High Energy Physics - Phenomenology
- [1] arXiv:2405.09625 [pdf, ps, html, other]
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Title: Fundamental Tests of P and CP Symmetries Using Octet Baryons at the $J/\psi$ ThresholdComments: 15 pages + 4 pages of appendix, 7 tables, 1 figureSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
We investigate tests of the parity P and the combined parity and charge-conjugate CP symmetries from differential angular distributions of $J/\psi$ decaying into the lowest-lying baryon pairs at BESIII and the next-generation super tau-charm facilities (STCFs). Large corrections from $Z$ and $W$ exchange induced parity violating effects are found for $J/\psi$ decays with large logarithms resummed up to $\mathcal{O}(\alpha_s)$. The parity-violating asymmetries on the production and the decay sides of $J/\psi$ are both found to be of $\mathcal{O}(10^{-4})$, thus barely observable with the 10 billion $J/\psi$ events currently collected at BESIII. Nevertheless, these asymmetries utilizing the current BESIII data already permit a determination of the weak mixing angle with an absolute uncertainty $\delta s_w^2\approx0.08$, corresponding to the first determination of $s_w^2$ at the $J/\psi$ threshold. While limited by statistics currently, STCFs are estimated to improve this precision by a factor of $\sim\,20$ to $\delta s_w^2\approx0.004$ within one year based on luminosity rescaling. We also obtain the 95% confidence level upper bounds on the electric dipole moments of the octet baryons, which are of $\mathcal{O}(10^{-18})\,e{\rm\,cm}$ for BESIII and $\mathcal{O}(10^{-19})\,e{\rm\,cm}$ for STCFs. These bounds are improved by two to three orders of magnitude in comparison with the only existing one on $\Lambda$ from Fermilab. The method discussed in this work also paves a way for a first and direct measurement of the $\Xi$ and $\Sigma$ electric dipole moments.
- [2] arXiv:2405.09629 [pdf, ps, other]
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Title: CaloDREAM $\unicode{x2013}$ Detector Response Emulation via Attentive flow MatchingSubjects: High Energy Physics - Phenomenology (hep-ph)
Detector simulations are an exciting application of modern generative networks. Their sparse high-dimensional data combined with the required precision poses a serious challenge. We show how combining Conditional Flow Matching with transformer elements allows us to simulate the detector phase space reliably. Namely, we use an autoregressive transformer to simulate the energy of each layer, and a vision transformer for the high-dimensional voxel distributions. We show how dimension reduction via latent diffusion allows us to train more efficiently and how diffusion networks can be evaluated faster with bespoke solvers. We showcase our framework, CaloDREAM, on datasets 2 and 3 of the CaloChallenge.
- [3] arXiv:2405.09650 [pdf, ps, html, other]
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Title: The neutral-pion decay into electron-positron pair: A review and updateTomáš Husek (Charles U. and Birmingham U.)Comments: 10 pages, 5 figures, 2 tablesSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
This work aims to review several aspects of the current status of the rare $\pi^0\to e^+e^-$ decay. A particular emphasis is made on radiative corrections and detailed interpretation of related quantities, some numbers appearing in the literature are updated, and the connection with the Dalitz decay, $\pi^0\to e^+e^-\gamma$, is discussed. This comes timely as it is aligned with an announcement of a preliminary result of a new branching-ratio measurement done by the NA62 Collaboration, which brings new light into an earlier-reported discrepancy between the Standard Model prediction and the (until-recently-latest) precise KTeV result.
- [4] arXiv:2405.09723 [pdf, ps, html, other]
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Title: Gravitational Wave-Induced Freeze-In of Fermionic Dark MatterComments: 6 pages, 2 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)
The minimal coupling of massless fermions to gravity does not allow for their gravitational production solely based on the expansion of the Universe. We argue that this changes in presence of realistic and potentially detectable stochastic gravitational wave backgrounds. We compute the resulting energy density of Weyl fermions at 1-loop using in--in formalism. If the initially massless fermions eventually acquire mass, this mechanism can explain the dark matter abundance in the Universe. Remarkably, it may be more efficient than conventional gravitational production of superheavy fermions.
- [5] arXiv:2405.09870 [pdf, ps, html, other]
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Title: NNLO+PS predictions for Higgs production via bottom annihilationComments: 4 pages, contribution to the 2024 QCD session of the 58th Rencontres de MoriondSubjects: High Energy Physics - Phenomenology (hep-ph)
We report on the implementation of a new NNLO+PS event generator for the Higgs production via bottom annihilation using the MiNNLOPS method in the POWHEG framework. The calculation has been carried out in the five flavour scheme (5FS), where the bottom mass is neglected. We compare our results against fixed-order predictions at NNLO as well as resummed predictions at next-to-next-to-leading-logarithmic (NNLL) accuracy. We also present a preliminary study in the four flavour scheme (4FS) setup, achieving a new level of precision in the massive scheme.
- [6] arXiv:2405.09926 [pdf, ps, html, other]
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Title: Twenty years of $\Theta^+$Comments: 22 pages, 3 figuras, contribution to Corfu Summer Institute 2023 "School and Workshops on Elementary Particle Physics and Gravity" (CORFU2023)Subjects: High Energy Physics - Phenomenology (hep-ph)
Twenty years ago, in 2003, two experimental groups, LEPS and DIANA, announced the discovery of a light, narrow, exotic baryon with mass within the range of 1540 MeV, which was later dubbed as $\Theta^+$. In this talk we recall the history of this discovery and its theoretical foundations. We also discuss possible future experiments that could determine the existence of $\Theta^+$.
- [7] arXiv:2405.09994 [pdf, ps, html, other]
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Title: Probing neutrino-nucleus interaction in DUNE and MicroBooNESubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex); Nuclear Theory (nucl-th)
The neutrino experiments utilize heavy nuclear targets to achieve high statistics neutrino-nucleus interaction event rate, which leads to systematic uncertainties in the oscillation parameters due to the nuclear effects and uncertainties in the cross-section. Understanding the interaction of neutrinos with the nucleus becomes crucial in determining the oscillation parameters with high precision. We investigate the uncertainty in quasi-elastic interaction due to nuclear effects by selecting exactly 1 proton, 0 pions, and any number of neutrons in the final state using DUNE and MicroBooNE detectors, and the effects on oscillation parameters in the DUNE detector. The kinematic method along with this selection can be used for accurate neutrino energy reconstruction in the quasi-elastic channel where the nuclear effects are inevitable.
- [8] arXiv:2405.10039 [pdf, ps, html, other]
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Title: High-Scale SUSY from Sgoldstino InflationComments: Prepared for the Proceedings of the Corfu Summer Institute 2023 -- Conference: C23-05-01Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
We review a number of unimodular no-scale supergravity models with F-term SUSY breaking which support technically natural de Sitter vacua. A variant of these models develops a stage of inflection-point inflation which can be realized for subplanckian field values consistently with the observational data. For central value of the spectral index ns, the necessary tuning is of the order of 10^-6, the tensor-to-scalar ratio is tiny whereas the running of ns is around -3x10^-3. Our proposal is compatible with high-scale SUSY and the results of LHC on the Higgs boson mass.
- [9] arXiv:2405.10056 [pdf, ps, html, other]
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Title: Shedding Light on Hadronization by Quarkonium Energy CorrelatorComments: 7 pages, 4 figures + supplemental materials (3 pages)Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
We propose to measure the energy correlator in quarkonium production, which tracks the energy deposited in the calorimeter $\chi$-angular distance away from the identified quarkonium. The observable eliminates the need for jets while sustaining the perturbative predictive power. Analyzing the power correction to the energy correlator, we demonstrate the novel observable supplies a unique gateway to probing the hadronization, especially when $\cos\chi\gtrsim 0$ in the quarkonium rest frame where the perturbative emissions are depleted due to the dead-cone effects. We expect the quarkonium energy correlator to add a new dimension to quarkonium studies.
- [10] arXiv:2405.10101 [pdf, ps, html, other]
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Title: Global analysis of the $U(3)^5$ symmetric SMEFTComments: 4 pages, 2 figures, contribution to the 2024 Electroweak session of the 58th Rencontres de MoriondSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
The $U(3)^5$ symmetry within the SMEFT framework restricts the inclusion of only fully flavor-conserving operators at dimension six. This proceeding presents a global analysis of the SMEFT under this assumption. We provide global constraints on all 41 Wilson coefficients, utilizing leading-order and next-to-leading-order SMEFT predictions for various experiments including parity-violating experiments, Electroweak Precision Observables (EWPO), Higgs physics, top quark interactions, flavor observables, dijet production, and lepton scatterings. We address issues concerning the constraints of specific four-quark operators, investigate correlations between observables at different energy scales, and assess the impact of next-to-leading-order contributions on the global fit.
- [11] arXiv:2405.10111 [pdf, ps, html, other]
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Title: The $a_1$ factorisation coefficient in ${\overline{B}^0} \to D^{(*)+}M^{-}$ and ${\overline{B}^0} \to D^{(*)+}D_s^{(*)-}$ decays: measurements versus theoryComments: 40 pagesSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
Using recent measurements of exclusive B-meson decays we extract the $a_1$ factorization parameter in ${\overline{B}^{0}_{d}} \to D^{(*)^+} K^-/\pi^-$ decay channels. { The values obtained in the four channels are very similar, in agreement with the theoretical expectations obtained in the $m_Q \to \infty$ limit, but the measured values differ definitely from the expected central values. } Such differences have already been observed. Using recent data, we improve the accuracy by {a factor close to two} in this comparison. We study possible interpretations for such a difference and conclude that the claimed accuracy of corrections due to soft gluon contributions and finite mass effects has to be revisited before arguing for possible "New-Physics" effects. We observe that the corrections to the $m_Q \to \infty$ limit are larger in the spectator topology than effects from exchange amplitude contributions. We discuss also the way expected ratios of $a_1$ values, involving hypotheses from theory, are used to obtain the fraction of $B^0_s$ meson production in jets at LHC and conclude that the uncertainties attached to this approach are not well established. Finally, the $a_1$ values extracted from $\overline{B}^{0}_{d} \to D^{(*)+} D_s^-$ decays are found to be similar, within uncertainties, to the ones obtained with $K^-$ emission, once expected penguin contributions are corrected. Using the same approach, we note that $a_1$ values measured in channels with a $D_s^{*-}$ emission are about two standard deviations lower than $a_1(D^{(*)+}K^-$).
- [12] arXiv:2405.10265 [pdf, ps, html, other]
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Title: Production of electroweak gauge bosons at forward rapidities in the color - dipole $S$ - matrix frameworkComments: 18 pages, 2 figures, 1 tableSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
The cross-section for the production of an electroweak gauge boson ($G = W^{\pm}, Z^0, \gamma$) at forward rapidities in $pp$ collisions is derived within the color - dipole $S$ - matrix framework. We present the full expressions for the differential cross-section of the $q p \rightarrow G X$ process in the impact parameter and transverse momentum spaces, considering the longitudinal and transverse polarizations of the gauge boson. The particular cases associated with the Drell - Yan process and real photon production are discussed. We demonstrate that the final formulae are expressed in terms of the dipole - proton cross-section or the unintegrated gluon distribution, and can be used to estimate the impact of the saturation effects in the gauge boson production at the LHC and future colliders.
- [13] arXiv:2405.10303 [pdf, ps, html, other]
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Title: Asymmetric Warm Dark Matter: from Cosmological Asymmetry to Chirality of LifeComments: 22pages, 3figures, comments are welcomeSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM); Biological Physics (physics.bio-ph)
We investigate a novel scenario involving asymmetric keV-range dark matter (DM) in the form of right-handed (sterile) neutrinos. Based on the Fermi-Dirac distribution, we demonstrate that asymmetric fermionic DM forms a Fermi degenerate gas, making it potentially colder than symmetric fermionic DM. This setup simultaneously accounts for the Universe's baryon asymmetry through tiny Yukawa interactions with Standard Model leptons and the Higgs field, and the homochirality of amino acids via decay into circularly polarized photons. This scenario can be investigated through soft X-ray searches conducted by current and upcoming space missions. The helical X-rays is a smoking-gun signal of our scenario. Additionally, we propose a new mechanism to suppress DM thermal production by introducing a light modulus, which may also benefit cosmology involving generic right-handed neutrinos with large mixing.
New submissions for Friday, 17 May 2024 (showing 13 of 13 entries )
- [14] arXiv:2405.07385 (cross-list from hep-th) [pdf, ps, html, other]
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Title: All-multiplicity amplitudes in impulsive PP-waves from the worldline formalismComments: 29 pages, 3 figuresSubjects: High Energy Physics - Theory (hep-th); High Energy Physics - Phenomenology (hep-ph)
We use the worldline formalism to derive Bern-Kosower type Master Formulae for the tree-level scattering of a charged particle and an arbitrary number of photons on impulsive PP-waves, where the coupling of the PP-wave to matter is treated fully non-perturbatively. We show that, in a certain kinematic regime characterised by a semi-classical positive energy condition, both off-shell currents and scattering amplitudes exhibit two novel factorisation structures. First, they may be written as currents in vacuum but with a single additional photon, averaged over the momentum of that photon. This converts the all-orders interaction with the PP-wave into a single effective interaction. Second, the currents and amplitudes may be written as a weighted average of the corresponding quantities in an impulsive plane wave background, with the average taken over all possible field strengths of the plane wave. This generalises a known single-photon result to arbitrary multiplicity.
- [15] arXiv:2405.09578 (cross-list from astro-ph.IM) [pdf, ps, html, other]
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Title: Dark Matter Halo Parameters from Overheated Exoplanets via Bayesian Hierarchical InferenceComments: Comments are welcome. 14 pages, 11 figures, 2 tablesSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP); High Energy Physics - Phenomenology (hep-ph)
Dark Matter (DM) can become captured, deposit annihilation energy, and hence increase the heat flow in exoplanets and brown dwarfs. Detecting such a DM-induced heating in a population of exoplanets in the inner kpc of the Milky Way thus provides potential sensitivity to the galactic DM halo parameters. We develop a Bayesian Hierarchical Model to investigate the feasibility of DM discovery with exoplanets and examine future prospects to recover the spatial distribution of DM in the Milky Way. We reconstruct from mock exoplanet datasets observable parameters such as exoplanet age, temperature, mass, and location, together with DM halo parameters, for representative choices of measurement uncertainty and the number of exoplanets detected. We find that detection of $\mathcal{O}(100)$ exoplanets in the inner Galaxy can yield quantitative information on the galactic DM density profile, under the assumption of 10% measurement uncertainty. Even as few as $\mathcal{O}(10)$ exoplanets can deliver meaningful sensitivities if the DM density and inner slope are sufficiently large.
- [16] arXiv:2405.09599 (cross-list from gr-qc) [pdf, ps, html, other]
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Title: Gravitational wave spectrum from expanding string loops on domain walls: Implication to nano-hertz pulsar timing array signalComments: 32 pages, 8 figuresSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
We analytically calculate the spectrum of stochastic gravitational waves (GWs) emitted by expanding string loops on domain walls in the scenario where domain walls decay by nucleation of string loops. By introducing macroscopic parameters characterizing the nucleation of the loops, the stochastic GW spectrum is derived in a way that is independent of the details of particle physics models. In contrast to GWs emitted from bubble collisions of the false vacuum decay, the string loops do radiate GWs even when they are perfectly circular before their collisions, resulting in that more and more contribution to the spectrum comes from the smaller and smaller loops compared to the typical size of the collided loops. Consequently, the spectrum is linearly proportional to the frequency at the high-frequency region, which is peculiar to this GW source. Furthermore, the results are compared with the recent nano-Hertz pulsar timing array signal, as well as the projected sensitivity curves of future gravitational wave observatories.
- [17] arXiv:2405.09607 (cross-list from astro-ph.CO) [pdf, ps, html, other]
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Title: Probing Dark Matter Isocurvature with Primordial Non-GaussianityComments: 17 pages, 4 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
Multiple fields can become dynamical during the inflationary epoch. We consider an example where a light field acquires isocurvature fluctuations during inflation and contributes to the dark matter abundance at late times. Interactions between the light field and the adiabatic sector contribute to mixed adiabatic-isocurvature non-Gaussianity (NG). We show the resulting form of NG has a different kinematic dependence than the 'local shape' commonly considered, and highlight the parameter space where a dedicated search is expected to significantly improve the current $\textit{Planck}$ sensitivity. We interpret our results in the context of the QCD axion and illustrate how the proposed NG searches can improve upon the existing searches for isocurvature power spectrum and bispectrum.
- [18] arXiv:2405.09608 (cross-list from hep-th) [pdf, ps, html, other]
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Title: All-order splits and multi-soft limits for particle and string amplitudesComments: 59 pages, 17 figuresSubjects: High Energy Physics - Theory (hep-th); High Energy Physics - Phenomenology (hep-ph)
The most important aspects of scattering amplitudes have long been thought to be associated with their poles. But recently a very different sort of "split" factorizations for a wide range of particle and string tree amplitudes have been discovered away from poles. In this paper, we give a simple, conceptual origin for these splits arising from natural properties of the binary geometry of the curve integral formulation for scattering amplitudes for Tr$(\Phi^3)$ theory. The most natural way of "joining" smaller surfaces to build larger ones directly produces a choice of kinematics for which higher amplitudes factor into lower ones. This gives a generalization of splits to all orders in the topological expansion. These splits allow us to access and compute loop-integrated multi-soft limits for particle and string amplitudes, at all loop orders. This includes split factorizations and multi-soft limits for pion and gluon amplitudes, that are related to Tr$(\Phi^3)$ theory by a simple kinematical shift.
- [19] arXiv:2405.09620 (cross-list from astro-ph.CO) [pdf, ps, html, other]
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Title: Probing Reheating with Gravitational Waves from Graviton BremsstrahlungComments: 6 pages, 4 figures. Contribution to the 2024 Electroweak session of the 58th Rencontres de Moriond. Based on Refs. arXiv:2301.11345, arXiv:2305.16388 and arXiv:2311.12694Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
In this talk, based on arXiv:2301.11345, arXiv:2305.16388, arXiv:2311.12694, we discuss the production of primordial gravitational waves (GW) sourced by graviton bremsstrahlung during inflationary reheating. For reheating, we consider inflaton decays and annihilations into pairs of bosons or fermions, assuming an inflaton $\phi$ that oscillates around a generic monomial potential $V(\phi) \propto \phi^n$. The GW spectrum exhibits distinct features depending on the underlying reheating dynamics, which is controlled by the inflaton potential and the type of coupling between the inflaton and the matter fields. We show that the produced stochastic GW background could be probed in next-generation GW detectors, especially at high frequencies. We further highlight the potential of bremsstrahlung-induced GW to probe the underlying dynamics of reheating.
- [20] arXiv:2405.09648 (cross-list from nucl-th) [pdf, ps, html, other]
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Title: BSQ Conserved Charges in Relativistic Viscous Hydrodynamics solved with Smoothed Particle HydrodynamicsChristopher Plumberg, Dekrayat Almaalol, Travis Dore, Débora Mroczek, Jordi Salinas San Martín, Willian M. Serenone, Lydia Spychalla, Patrick Carzon, Matthew D. Sievert, Fernando G. Gardim, Jacquelyn Noronha-HostlerComments: 51 pages, 28 FiguresSubjects: Nuclear Theory (nucl-th); High Energy Physics - Phenomenology (hep-ph)
Conservation laws play a crucial role in the modeling of heavy-ion collisions, including the those for charges such as baryon number (B), strangeness (S), and electric charge (Q). In this study, we present a new 2+1 relativistic viscous hydrodynamic code called CCAKE which uses the Smoothed Particle Hydrodynamics (SPH) formalism to locally conserve BSQ charges, together with an extended description of the multi-dimensional equation of state (EoS) obtained from lattice Quantum Chromodynamics. Initial conditions for CCAKE are supplied by the ICCING model, which samples gluon splittings into quark anti-quark pairs to generate the initial BSQ charge distributions. We study correlations between the BSQ charges and find that local BSQ fluctuations remain finite during the evolution, with corresponding chemical potentials of ($\sim100$--$200 \,\rm MeV$) at freeze-out. We find that our framework produces reasonable multiplicities of identified particles and that ICCING has no significant effect on the collective flow of all charged particles nor of identified particles when only one particle of interest is considered. However, we show specifically for Pb+Pb collisions at the LHC $\sqrt{s_{NN}}=5.02$ TeV that ICCING does have an effect on collective flow of identified particles if two particles of interest are considered.
- [21] arXiv:2405.09714 (cross-list from gr-qc) [pdf, ps, html, other]
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Title: Cosmological Singularity and Power-Law Solutions in Modified GravitySubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
A bouncing Universe avoids the big-bang singularity. Using the time-like and null Raychaudhhuri equations, we explore whether the bounce near the big-bang, within a broad spectrum of modified theories of gravity, allows for cosmologically relevant power-law solutions under reasonable physical conditions. Our study shows that certain modified theories of gravity, such as Stelle gravity, do not demonstrate singularity resolution under any reasonable conditions, while others including $f(R)$ gravity and Brans-Dicke theory can demonstrate singularity resolution under suitable conditions. For these theories, we show that the accelerating solution is slightly favoured over ekypyrosis.
- [22] arXiv:2405.09790 (cross-list from astro-ph.CO) [pdf, ps, html, other]
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Title: Supermassive black hole formation from Affleck-Dine mechanism with suppressed clustering on large scalesComments: 26 pages, 7 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
We study a primordial black hole (PBH) formation model based on the framework of the inhomogeneous Affleck-Dine (AD) mechanism, which can explain the seeds of supermassive black holes (SMBHs). This model, however, predicts strong clustering of SMBHs that is inconsistent with the observation of angular correlation of quasars. In this paper, we propose a modified model that can significantly reduce the PBH clustering on large scales by considering a time-dependent Hubble-induced mass during inflation. The quasar angular correlation is suppressed by the large Hubble-induced mass in the early stage of inflation while the small Hubble-induced mass in the late stage leads to the AD field fluctuations large enough for PBH formation as in the original model. As a result, the modified scenario can successfully explain the seeds of SMBHs.
- [23] arXiv:2405.09971 (cross-list from nucl-th) [pdf, ps, html, other]
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Title: A study of the fine-structure constant dependence of radiative capture in Halo-EFTComments: 17 pages, 14 figuresSubjects: Nuclear Theory (nucl-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th); Nuclear Experiment (nucl-ex)
We study the fine-structure constant dependence of the rates of some selected radiative capture reactions within the framework of so-called Halo Effective Field Theory in order to assess the adequacy of some assumptions made on the Coulomb penetrability. We find that this dependence deviates from that implied by a parameterization of the cross sections of this effect via a simple penetration factor. Some features of this fine-structure dependence are discussed, in particular its potential impact on the abundances of the light elements in primordial nucleosynthesis.
- [24] arXiv:2405.10106 (cross-list from hep-ex) [pdf, ps, html, other]
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Title: Advancing Set-Conditional Set Generation: Graph Diffusion for Fast Simulation of Reconstructed ParticlesComments: 18 pages, 10 figures, 1 tableSubjects: High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph)
The computational intensity of detailed detector simulations poses a significant bottleneck in generating simulated data for collider experiments. This challenge inspires the continued development of fast simulation techniques based on machine learning to serve as efficient surrogate models. In our approach, a network generates a set of reconstructed objects conditioned on input particle sets. Building on the success of a slot-attention-based model, we present a new architecture utilizing diffusion, showcasing an enhanced performance in the context of single jets.
- [25] arXiv:2405.10137 (cross-list from hep-th) [pdf, ps, html, other]
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Title: Light-ray sum rules and the c-anomalySubjects: High Energy Physics - Theory (hep-th); High Energy Physics - Phenomenology (hep-ph)
In a four-dimensional quantum field theory that flows between two fixed points under the renormalization group, the change in the conformal anomaly $\Delta a$ has been related to the average null energy. We extend this result to derive a sum rule for the other anomaly coefficient, $\Delta c$, in terms of the stress tensor three-point function. While the sum rule for $\Delta a$ is an expectation value of the averaged null energy operator, and therefore positive, the result for $\Delta c$ involves the off-diagonal matrix elements, so it does not have a fixed sign.
- [26] arXiv:2405.10201 (cross-list from gr-qc) [pdf, ps, html, other]
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Title: Investigating cosmic histories with a stiff era through Gravitational WavesComments: 18 pages, 9 figuresSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
We investigate the potential of gravitational-wave background searches to constrain cosmic histories characterised by a stiff equation of state, preceded by a period of matter domination. Such a scenario leads to a characteristic peak in the primordial gravitational-wave spectrum originating from cosmological inflation. Assuming instant transitions between distinct epochs, which allows an analytical treatment of the gravitational-wave spectrum, we perform a Bayesian inference analysis to derive constraints from the first three observing runs of the LIGO-Virgo-KAGRA Collaboration. Additionally, we consider a smooth transition, employing an axion-like particle physics model, and highlight the difference with the instant transition approximation. We then forecast detection prospects for such a cosmic history through future gravitational-wave experiments.
- [27] arXiv:2405.10261 (cross-list from hep-ex) [pdf, ps, html, other]
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Title: Summary of CKM 2023 working group 5: Direct CP violation (DCPV) including $\phi_{3}/\gamma$ from $B\to DK$, DCPV effects, branching fractions and polarisation in charmless $B_{(s)}$ decaysComments: 35 pages, 13 figures, Presented at the 12th Workshop on the CKM Unitarity Triangle, 18-22 September 2023, Santiago de CompostelaSubjects: High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph)
In this contribution a summary of the activities of Working Group 5 (WG5) presented during the 12th International Workshop on the CKM Unitarity Triangle (CKM2023) is reported. This includes new results on $\phi_{3}/\gamma$ measurements using $B\to DK$ decays, search for $CP$ violation using charmless $B$ decays and $b$-Baryon decays, measurement of branching ratios in hadronic $B$ to charm decays, and theory of three-body nonleptonic $B$ decays.
- [28] arXiv:2405.10268 (cross-list from nucl-th) [pdf, ps, html, other]
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Title: The Magic in Nuclear and Hypernuclear ForcesComments: 14 pages, 6 figuresSubjects: Nuclear Theory (nucl-th); High Energy Physics - Phenomenology (hep-ph); Quantum Physics (quant-ph)
Toward an improved understanding of the role of quantum information in nuclei and exotic matter, we examine the magic (non-stabilizerness) in low-energy strong interaction processes. As stabilizer states can be prepared efficiently using classical computers, and include classes of entangled states, it is magic and fluctuations in magic, along with entanglement, that determine resource requirements for quantum simulations. As a measure of fluctuations in magic induced by scattering, the "magic power" of the S-matrix is introduced. Using experimentally-determined scattering phase shifts and mixing parameters, the magic power in nucleon-nucleon and hyperon-nucleon scattering, along with the magic in the deuteron, are found to exhibit interesting features. The $\Sigma^-$-baryon is identified as a potential candidate catalyst for enhanced spreading of magic and entanglement in dense matter, depending on in-medium decoherence.
- [29] arXiv:2405.10284 (cross-list from quant-ph) [pdf, ps, html, other]
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Title: Quantum Vision Transformers for Quark-Gluon ClassificationMarçal Comajoan Cara, Gopal Ramesh Dahale, Zhongtian Dong, Roy T. Forestano, Sergei Gleyzer, Daniel Justice, Kyoungchul Kong, Tom Magorsch, Konstantin T. Matchev, Katia Matcheva, Eyup B. UnluComments: 14 pages, 8 figures. Published in MDPI Axioms 2024, 13(5), 323Journal-ref: Axioms 2024, 13(5), 323Subjects: Quantum Physics (quant-ph); Machine Learning (cs.LG); High Energy Physics - Phenomenology (hep-ph)
We introduce a hybrid quantum-classical vision transformer architecture, notable for its integration of variational quantum circuits within both the attention mechanism and the multi-layer perceptrons. The research addresses the critical challenge of computational efficiency and resource constraints in analyzing data from the upcoming High Luminosity Large Hadron Collider, presenting the architecture as a potential solution. In particular, we evaluate our method by applying the model to multi-detector jet images from CMS Open Data. The goal is to distinguish quark-initiated from gluon-initiated jets. We successfully train the quantum model and evaluate it via numerical simulations. Using this approach, we achieve classification performance almost on par with the one obtained with the completely classical architecture, considering a similar number of parameters.
- [30] arXiv:2405.10304 (cross-list from hep-lat) [pdf, ps, html, other]
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Title: Towards Unpolarized GPDs from Pseudo-DistributionsH. Dutrieux, R. Edwards, C. Egerer, J. Karpie, C. Monahan, K. Orginos, A. Radyushkin, D. Richards, E. Romero, S. ZafeiropoulosComments: 56 pages, 24 figuresSubjects: High Energy Physics - Lattice (hep-lat); High Energy Physics - Phenomenology (hep-ph)
We present an exploration of the unpolarized isovector proton generalized parton distributions (GPDs) $H^{u-d}(x, \xi, t)$ and $E^{u-d}(x, \xi, t)$ in the pseudo-distribution formalism using distillation. Taking advantage of the large kinematic coverage made possible by this approach, we present results on the moments of GPDs up to the order $x^3$ -- including their skewness dependence -- at a pion mass $m_\pi = 358$ MeV and a lattice spacing $a = 0.094$ fm.
- [31] arXiv:2405.10321 (cross-list from gr-qc) [pdf, ps, html, other]
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Title: Probing Hidden Dimensions via Muon Lifetime MeasurementsComments: Honorable Mention in the Gravity Research Foundation 2024 Awards for Essays on Gravitation. 11 pagesSubjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
In the context of Kaluza-Klein theories, the time dilation of charged particles in an external field depends on the charge in a specific way. Experimental tests are proposed to search for extra dimensions using this distinctive feature.
Cross submissions for Friday, 17 May 2024 (showing 18 of 18 entries )
- [32] arXiv:1912.13386 (replaced) [pdf, ps, other]
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Title: Infrared structure of $SU(N)\times U(1)$ gauge theory to three loopsComments: The updated version, which include corrected expression for beta function, mixed QCD-QED anomalous dimensions and soft-virtual parsonic cross sectionSubjects: High Energy Physics - Phenomenology (hep-ph)
We study the infrared (IR) structure of $SU(N) \times U(1)$ (QCD $\times$ QED) gauge theory with $n_f$ quarks and $n_l$ leptons within the framework of perturbation theory. In particular, we unravel the IR structure of the form factors and inclusive real emission cross sections that contribute to inclusive production of color neutral states, such as a pair of leptons or single W/Z in Drell-Yan processes and a Higgs boson in bottom quark annihilation, in Large Hadron Collider (LHC) in the threshold limit. Explicit computation of the relevant form factors to third order and the use of Sudakov's $K+G$ equation in $SU(N)\times U(1)$ gauge theory demonstrate the universality of the cusp anomalous dimensions ($A_I , I = q, b$). The abelianization rules that relate $A_I$ of $SU(N)$ with those from $U(1)$ and $SU(N)\times U(1)$ can be used to predict the soft distribution that results from the soft gluon emission subprocesses in the threshold limit. Using the latter and the third order form factors, we can obtain the collinear anomalous dimensions ($B_I$ ) and the renormalisation constant $Z_b$ to third order in perturbation theory. The form factors, the process independent soft distribution functions can be used to predict fixed and resummed inclusive cross sections to third order in couplings and in leading logarithmic approximation respectively.
- [33] arXiv:2206.14441 (replaced) [pdf, ps, html, other]
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Title: Quantum Chromodynamics Resolution of the ATOMKI Anomaly in ${\rm {^4He}}$ Nuclear TransitionsComments: Experimental signatures of the model added, 9 pages, 3 figures, comments welcomeSubjects: High Energy Physics - Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
Observations of anomalous angular correlations in electron-positron pairs produced from excited states of $^{4}$He, $^{8}$Be and $^{12}$C nuclei have been suggested as due to the creation and subsequent decay of a new light particle of mass $\sim$17 MeV. In this work, we investigate the possibility that the source of the observed signals is a set of new excitation channels created by the 12-quark hidden-color Fock state within the ${\rm {^4He}}$ nuclear wavefunction dubbed the "hexadiquark." We calculate the invariant $e^+e^-$ mass spectrum for the electromagnetic transition from a new excitation of $^{4}$He, estimating its differential and total decay width. We find that we can fit the shape of the anomalous signal with the QCD Fock state at excitation energy $\rm E^{*} = 17.9 \pm 1$ MeV and a Gaussian form factor for the electromagnetic decay. We address the physical issues with the fit parameters using properties of the hexadiquark state, in particular the three weakly repulsive $\rm 6_C$ interactions of $\rm SU(3)_C$ between diquark pairs. Experimental tests of our model are described in detail. In light of this work, we emphasize the need for independent experimental confirmation or refutation of the ATOMKI results as well as dedicated experiments to search for the proposed new excitations of ${\rm ^4He}$ and other $\alpha$-cluster nuclei.
- [34] arXiv:2209.07541 (replaced) [pdf, ps, html, other]
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Title: Improved Constraints on Dark Matter Annihilations Around Primordial Black HolesComments: 37 pages, 11 FiguresSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Cosmology may give rise to appreciable populations of both particle dark matter and primordial black holes (PBH) with the combined mass density providing the observationally inferred value $\Omega_{\rm DM}\approx0.26$. However, previous studies have highlighted that scenarios with both particle dark matter and PBH are strongly excluded by $\gamma$-ray limits for particle dark matter with a velocity independent thermal cross section $\langle\sigma v\rangle\sim3\times10^{-26}{\rm cm}^3/{\rm s}$, as is the case for classic WIMP dark matter. Here we extend these existing studies on $s$-wave annihilating particle dark matter to ascertain the limits from diffuse $\gamma$-rays on velocity dependent annihilations which are $p$-wave with $\langle\sigma v \rangle\propto v^2$ or $d$-wave with $\langle\sigma v \rangle\propto v^4$, which we find to be considerably less constraining. Furthermore, we highlight that even if the freeze-out process is $p$-wave it is relatively common for (loop/phase-space) suppressed $s$-wave processes to actually provide the leading contributions to the experimentally constrained $\gamma$-ray flux from the PBH halo. This work also utilyses a refined treatment of the PBH dark matter density profile and outlines an improved application of extra-galactic $\gamma$-ray bounds.
- [35] arXiv:2306.17239 (replaced) [pdf, ps, html, other]
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Title: Can supercooled phase transitions explain the gravitational wave background observed by pulsar timing arrays?Comments: 12 pages, 3 figures, Replaced to match published version in PRLSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Several pulsar timing array collaborations recently reported evidence of a stochastic gravitational wave background (SGWB) at nHz frequencies. Whilst the SGWB could originate from the merger of supermassive black holes, it could be a signature of new physics near the 100 MeV scale. Supercooled first-order phase transitions (FOPTs) that end at the 100 MeV scale are intriguing explanations, because they could connect the nHz signal to new physics at the electroweak scale or beyond. Here, however, we provide a clear demonstration that it is not simple to create a nHz signal from a supercooled phase transition, due to two crucial issues that could rule out many proposed supercooled explanations and should be checked. As an example, we use a model based on non-linearly realized electroweak symmetry that has been cited as evidence for a supercooled explanation. First, we show that a FOPT cannot complete for the required transition temperature of around 100 MeV. Such supercooling implies a period of vacuum domination that hinders bubble percolation and transition completion. Second, we show that even if completion is not required or if this constraint is evaded, the Universe typically reheats to the scale of any physics driving the FOPT. The hierarchy between the transition and reheating temperature makes it challenging to compute the spectrum of the SGWB.
- [36] arXiv:2309.09743 (replaced) [pdf, ps, html, other]
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Title: The NFLikelihood: an unsupervised DNNLikelihood from Normalizing FlowsComments: 16 pages, 5 figures, 11 tables. Minor revisionSubjects: High Energy Physics - Phenomenology (hep-ph); Machine Learning (cs.LG); High Energy Physics - Experiment (hep-ex)
We propose the NFLikelihood, an unsupervised version, based on Normalizing Flows, of the DNNLikelihood proposed in Ref.[1]. We show, through realistic examples, how Autoregressive Flows, based on affine and rational quadratic spline bijectors, are able to learn complicated high-dimensional Likelihoods arising in High Energy Physics (HEP) analyses. We focus on a toy LHC analysis example already considered in the literature and on two Effective Field Theory fits of flavor and electroweak observables, whose samples have been obtained throught the HEPFit code. We discuss advantages and disadvantages of the unsupervised approach with respect to the supervised one and discuss possible interplays of the two.
- [37] arXiv:2311.09012 (replaced) [pdf, ps, html, other]
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Title: Estimation of the chances to find new phenomena at the LHC in a model-agnostic combinatorial analysisComments: 13 pages,1 figure, submitted to a journalSubjects: High Energy Physics - Phenomenology (hep-ph)
In this paper, we estimate the number of event topologies that have the potential to be produced in $pp$ collisions at the Large Hadron Collider (LHC) without violating kinematic and other constraints. We use numerical calculations and combinatorics, guided by large-scale Monte Carlo simulations of Standard Model (SM) processes. Then, we set the upper limit on the probability that new physics may escape detection, assuming a model-agnostic approach. The calculated probability is unexpectedly large, and the fact that the LHC has not found new physics until now is not entirely surprising. We argue that the optimal direction for maximizing the chances of finding new physics is to use unsupervised machine learning for anomaly detection or algorithms designed for event classification.
- [38] arXiv:2312.02270 (replaced) [pdf, ps, html, other]
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Title: Study of a cubic cavity resonator for gravitational waves detection in the microwave frequency rangeComments: 26 pages, 12 figures; v2 matches published versionSubjects: High Energy Physics - Phenomenology (hep-ph); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Experiment (hep-ex); Instrumentation and Detectors (physics.ins-det)
The direct detection of gravitational waves (GWs) of frequencies above MHz has recently received considerable attention. In this work we present a precise study of the reach of a cubic cavity resonator to GWs in the microwave range, using for the first time tools allowing to perform realistic simulations. Concretely, the BI-RME 3D method, which allows us to obtain not only the detected power but also the detected voltage (magnitude and phase), is used here. After analyzing three cubic cavities for different frequencies and working simultaneously with three different degenerate modes at each cavity, we conclude that the sensitivity of the experiment is strongly dependent on the polarization and incidence angle of the GW. The presented experiment can reach sensitivities up to $ 1 \cdot 10^{-19}$ at 100\, MHz, $ 2 \cdot 10^{-20}$ at 1\, GHz, and $ 6 \cdot 10^{-19}$ at 10\, GHz for optimal angles and polarizations, and where in all cases we assumed an integration time of $\Delta t = 1$ ms. These results provide a strong case for further developing the use of cavities to detect GWs. Moreover, the possibility of analyzing the detected voltage (magnitude and phase) opens a new interferometric detection scheme based on the combination of the detected signals from multiple cavities.
- [39] arXiv:2312.14016 (replaced) [pdf, ps, html, other]
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Title: LHCb potential to discover long-lived new physics particles with lifetimes above 100 psVolodymyr Gorkavenko, Brij Jashal, Valerii Kholoimov, Yehor Kyselov, Diego Mendoza, Maksym Ovchynnikov, Arantza Oyanguren, Volodymyr Svintozelskyi, Jiahui ZhuoComments: Matches the version accepted for the publication in EPJCSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
For years, it has been believed that the main LHC detectors can only restrictively play the role of a lifetime frontier experiment exploring the parameter space of long-lived particles (LLPs) - hypothetical particles with tiny couplings to the Standard Model. This paper demonstrates that the LHCb experiment may become a powerful lifetime frontier experiment if it uses the new Downstream algorithm reconstructing tracks that do not let hits in the LHCb vertex tracker. In particular, for many LLP scenarios, LHCb may be as sensitive as the proposed experiments beyond main LHC detectors for various LLP models, including heavy neutral leptons, dark scalars, dark photons, and axion-like particles.
- [40] arXiv:2402.12322 (replaced) [pdf, ps, html, other]
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Title: Simultaneous reweighting of Transverse Momentum Dependent distributionsMariaelena Boglione, Umberto D'Alesio, Carlo Flore, Josè Osvaldo Gonzalez-Hernandez, Francesco Murgia, Alexei ProkudinComments: 11 pages, 11 figures. Revised results section, extended discussion on Bayesian reweighting. To appear on Physics Letters BSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex); High Energy Physics - Theory (hep-th); Nuclear Theory (nucl-th)
The Bayesian reweighting procedure is extended to the case of multiple independent extractions of transverse momentum dependent parton distributions (TMDs). By exploiting the data on transverse single spin asymmetries, $A_N$, for inclusive pion production in polarized proton-proton collisions measured at RHIC, we perform a simultaneous reweighting of the quark Sivers, transversity and Collins TMD functions extracted from semi-inclusive deep inelastic scattering (SIDIS) and $e^+ e^-$ annihilation into hadron pairs. The impact of the implementation of the Soffer bound, as well as the differences between older and newer $A_N$ data, are investigated. The agreement with $A_N$ data at large-$x_F$ values, a kinematical region complementary to those explored in SIDIS measurements, is enhanced, improving the knowledge of the polarized quark TMDs in the large-$x$ region.
- [41] arXiv:2402.14097 (replaced) [pdf, ps, html, other]
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Title: Introductory visual lecture on QCD at large-$N_{c}$: bound states, chiral models, and phase diagramComments: 104 pages, 51 figures. Lectures prepared for the 63. Cracow School of Theoretical Physics, September 17-23, 2023 Zakopane, Tatra Mountains, Poland. Update and corrected vs with restyling of figuresSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th); Nuclear Theory (nucl-th)
In these lectures, we present the behavior of conventional $\bar{q}q$ mesons, glueballs, and hybrids in the large-$N_{c}$ limit of QCD. To this end, we use an approach based on rather simple NJL-like bound-state equations. The obtained large-$N_{c}$ scaling laws are general and coincide with the known results. A series of consequences, such as the narrowness of certain mesons and the smallness of some interaction types, the behavior of chiral and dilaton models at large-$N_{c},$ and the relation to the compositeness condition and the standard derivation of large-$N_{c}$ results, are explained. The bound-state formalism shows also that mesonic molecular and dynamically generated states do not form in the large-$N_{c}$ limit. The same fate seems to apply also for tetraquark states, but here further studies are needed. Next, following the same approach, baryons are studied as bound states of a generalized diquark ($N_{c}-1$ antisymmetric object) and a quark. Similarities and differences with regular mesons are discussed. All the standard scaling laws for baryons and their interaction with mesons are correctly reproduced. The behavior of chiral models involving baryons and describing chirally invariant mass generation is investigated. Finally, properties of QCD in the medium at large-$N_{c}$ are studied: the deconfinement phase transition is investigated along the temperature and the chemical potential directions, respectively. Within the QCD phase diagrams, the features of different models at large-$N_{c}$ are reviewed and the location of the critical endpoint is discussed. In the end, the very existence of nuclei and the implications of large-$N_{c}$ arguments for neutron stars are outlined.
- [42] arXiv:2403.07084 (replaced) [pdf, ps, html, other]
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Title: Is the effective potential, effective for dynamics?Comments: 51 pages, 5 figures, more references and discussionsJournal-ref: Phys. Rev. D 109, 105021 (2024)Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th); Quantum Physics (quant-ph)
We critically examine the applicability of the effective potential within dynamical situations and find, in short, that the answer is negative. An important caveat of the use of an effective potential in dynamical equations of motion is an explicit violation of energy conservation.
An \emph{adiabatic} effective potential is introduced in a consistent quasi-static approximation, and its narrow regime of validity is discussed. Two ubiquitous instances in which even the adiabatic effective potential is not valid in dynamics are studied in detail: parametric amplification in the case of oscillating mean fields, and spinodal instabilities associated with spontaneous symmetry breaking. In both cases profuse particle production is directly linked to the failure of the effective potential to describe the dynamics. We introduce a consistent, renormalized, energy conserving dynamical framework that is amenable to numerical implementation. Energy conservation leads to the emergence of asymptotic highly excited, entangled stationary states from the dynamical evolution. As a corollary, decoherence via dephasing of the density matrix in the adiabatic basis is argued to lead to an emergent entropy, formally equivalent to the entanglement entropy. The results suggest novel characterization of asymptotic equilibrium states in terms of order parameter vs. energy density. - [43] arXiv:2403.12692 (replaced) [pdf, ps, html, other]
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Title: Mass spectra of heavy hybrid quarkonia and $\overline{b}gc$ mesonsComments: 13 Pages, 5 Figures and 5 TablesSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex); High Energy Physics - Lattice (hep-lat)
Masses and current couplings of the charmonium and bottomonium hybrids $ \overline{c}gc$ and $\overline{b}gb$ with spin-parities $J^{\mathrm{PC} }=0^{++},\ 0^{+-},\ 0^{-+},\ 0^{--}$ and $1^{++},\ 1^{+-},\ 1^{-+},\ 1^{--}$ are calculated using QCD two-point sum rule method. Computations are performed by taking into account gluon condensates up to dimension 12 including terms $\sim \langle g_{s}^{3}G^{3}\rangle ^{2}$. The parameters of the bottom-charm hybrids $\overline{b}gc$ with quantum numbers $J^{\mathrm{PC }}=0^{+},\ 0^{-},\ 1^{+}$, and $1^{-}$ are calculated as well. In computations the dominance of the pole contribution to sum rule results is ensured. It is demonstrated that all charmonia hybrids decay strongly to two-meson final states. The bottomonium hybrids $0^{-+}$ and $1^{-+}$ as well as the bottom-charm hybrid mesons $0^{-(+)}$ and $1^{-(+)}$ may be stable against strong two-meson decay modes. Results of the present work are compared with ones obtained using the sum rule and alternative approaches. Our predictions for parameters of the heavy hybrid mesons may be useful to study their various decay channels which are important for interpretation of ongoing and future experiments.
- [44] arXiv:2404.12996 (replaced) [pdf, ps, html, other]
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Title: Axion-induced Casimir force between nuclei and dynamical axion pair creationComments: 6 pages, 1 figureSubjects: High Energy Physics - Phenomenology (hep-ph)
We study the interaction between axions and nuclei by combining the Peccei-Quinn mechanism with results from quantum chromo-dynamics (QCD) which imply that the QCD condensates are reduced within nuclear matter. Thus, the effective axion mass is also reduced, yielding a finite axion-nucleon scattering cross section. Even in the absence of real axions, this interaction would manifest itself in a Casimir type attraction between two nuclei. Finally, accelerated nuclei can create entangled pairs of axions via the dynamical Casimir effect (or as signatures of the Unruh effect).
- [45] arXiv:2404.17526 (replaced) [pdf, ps, html, other]
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Title: QCD analysis of $xF_3$ structure functions in deep-inelastic scattering: Mellin transform by Gegenbauer polynomial up to N$^3$LO approximationComments: 9 pages, 8 figures, 2 tablesSubjects: High Energy Physics - Phenomenology (hep-ph)
This paper provides a thorough examination of the $xF_3$ structure functions in deep-inelastic scattering through a comprehensive QCD analysis. Our approach harnesses sophisticated mathematical techniques, namely the Mellin transform combined with Gegenbauer polynomials. We have employed the Jacobi polynomials approach for analysis, conducting investigations at three levels of precision: Next-to-Leading Order (NLO), Next-to-Next-to-Leading Order (N$^2$LO), and Next-Next-Next-to-Leading Order (N$^3$LO). We have performed a comparison of our sets of valence-quark parton distribution functions with those of recent research groups, specifically CT18 and MSHT20 at NLO and N$^2$LO, and MSTH23 at N$^3$LO, which are concurrent with our current analysis. The combination of Mellin transforms with Gegenbauer polynomials proves to be a powerful tool for investigating the $xF_3$ structure functions in deep-inelastic scattering and the results obtained from our analysis demonstrate a favorable alignment with experimental data.
- [46] arXiv:2405.06970 (replaced) [pdf, ps, html, other]
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Title: Leptoquark-induced CLFV decays with a light SM-singlet scalarComments: 8 pages, 8 figures, 3 tablesSubjects: High Energy Physics - Phenomenology (hep-ph)
The Standard Model (SM), if augmented with a light SM-singlet scalar $\phi$, 2-body charged lepton flavor violating (CLFV) decay channels can be accessed with $\phi$ as one of the final states. The effective ineteractions between $\phi$ and the SM fields can arise at TeV-scale where the governing theory extends the SM particle spectrum with a scalar leptoquark (LQ) $S_1$. Further, in the presence of $S_1$, $\phi$ can mediate 3-body CLFV processes with either two photons or two gluons in the final states. Thus, the model predicts an exotic 3-body CLFV channel: $\ell_A\to\ell_B gg$, which can be tested/constrained only through some future high-energy experiments looking for di-gluon signal from a leptonic decay.
- [47] arXiv:2210.14245 (replaced) [pdf, ps, html, other]
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Title: CaloFlow for CaloChallenge Dataset 1Comments: 36 pages, 21 figures, v3: match published versionJournal-ref: SciPost Phys. 16, 126 (2024)Subjects: Instrumentation and Detectors (physics.ins-det); Machine Learning (cs.LG); High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph); Data Analysis, Statistics and Probability (physics.data-an)
CaloFlow is a new and promising approach to fast calorimeter simulation based on normalizing flows. Applying CaloFlow to the photon and charged pion Geant4 showers of Dataset 1 of the Fast Calorimeter Simulation Challenge 2022, we show how it can produce high-fidelity samples with a sampling time that is several orders of magnitude faster than Geant4. We demonstrate the fidelity of the samples using calorimeter shower images, histograms of high-level features, and aggregate metrics such as a classifier trained to distinguish CaloFlow from Geant4 samples.
- [48] arXiv:2306.12914 (replaced) [pdf, ps, html, other]
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Title: The Dilaton Improves GoldstonesComments: 19 pages + refs, 1 figure, major revision. Includes discussion on Weyl-gauging and more general soft theorem discussionSubjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Lattice (hep-lat); High Energy Physics - Phenomenology (hep-ph)
The free scalar field is only conformally invariant when non-minimally coupled to gravity. In flat space this amounts to amending, or improving, the energy momentum tensor. A no-go theorem prohibits the improvement for Goldstone bosons, originating from global internal spontaneous symmetry breaking. It is shown that the no-go theorem can be circumvented in the presence of a dilaton. The latter is a (pseudo) Goldstone boson originating from spontaneous conformal symmetry breaking in a theory with an infrared fixed point. Specifically, the tracelessness of the energy momentum tensor is demonstrated for a generic $d$-dimensional curved space. Additionally, the Goldstone gravitational form factors are shown to obey conformality constraints in the soft limit. The crucial point is that the remainder term of the soft theorem is non-zero due to the presence of the dilaton pole. For Goldstone systems with a trivial infrared fixed point the leading order analysis of this paper ought to be sufficient. Loop effects govern the improvement term outside the fixed point and are scheme-dependent as briefly discussed towards the end of the paper.
- [49] arXiv:2308.11700 (replaced) [pdf, ps, html, other]
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Title: Calorimeter shower superresolutionComments: 16 pages, 13 figures, v3: title changed, matches published versionJournal-ref: Phys. Rev. D 109, 092009 (2024)Subjects: Instrumentation and Detectors (physics.ins-det); Machine Learning (cs.LG); High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph); Data Analysis, Statistics and Probability (physics.data-an)
Calorimeter shower simulation is a major bottleneck in the Large Hadron Collider computational pipeline. There have been recent efforts to employ deep-generative surrogate models to overcome this challenge. However, many of best performing models have training and generation times that do not scale well to high-dimensional calorimeter showers. In this work, we introduce SuperCalo, a flow-based superresolution model, and demonstrate that high-dimensional fine-grained calorimeter showers can be quickly upsampled from coarse-grained showers. This novel approach presents a way to reduce computational cost, memory requirements and generation time associated with fast calorimeter simulation models. Additionally, we show that the showers upsampled by SuperCalo possess a high degree of variation. This allows a large number of high-dimensional calorimeter showers to be upsampled from much fewer coarse showers with high-fidelity, which results in additional reduction in generation time.
- [50] arXiv:2308.12330 (replaced) [pdf, ps, html, other]
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Title: Astrometric Weak Lensing with Gaia DR3 and Future Catalogs: Searches for Dark Matter SubstructureComments: 16 pages, 8 figures; v2: published version, references and minor comments addedSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA); High Energy Physics - Phenomenology (hep-ph)
Small-scale dark matter structures lighter than a billion solar masses are an important probe of primordial density fluctuations and dark matter microphysics. Due to their lack of starlight emission, their only guaranteed signatures are gravitational in nature. We report on results of a search for astrometric weak lensing by compact dark matter subhalos in the Milky Way with Gaia DR3 data. Using a matched-filter analysis to look for correlated imprints of time-domain lensing on the proper motions of background stars in the Magellanic Clouds, we exclude order-unity substructure fractions in halos with masses $M_{l}$ between $10^{7} \, M_{\odot}$ and $10^{9} \, M_{\odot}$ and sizes of one parsec or smaller. We forecast that a similar approach based on proper accelerations across the entire sky with data from Gaia DR4 may be sensitive to substructure fractions of $f_{l} \gtrsim 10^{-3}$ in the much lower mass range of $10 \, M_{\odot} \lesssim M_{l} \lesssim 3 \times 10^{3} \, M_{\odot}$. We further propose an analogous technique for stacked star-star lensing events in the regime of large impact parameters. Our first implementation is not yet sufficiently sensitive but serves as a useful diagnostic and calibration tool; future data releases should enable average stellar mass measurements using this stacking method.
- [51] arXiv:2311.04977 (replaced) [pdf, ps, html, other]
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Title: A visual tool for assessing tension-resolving models in the $H_0$-$\sigma_8$ planeComments: 15 pages, 3 figures, 5 tables. Replaced to match PRD accepted version (May 2024)Journal-ref: Phys. Rev. D 109, 103525 (2024)Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
Beyond-$\Lambda$CDM models have been proposed to address various shortcomings of the standard cosmological model, such as the ``Hubble tension.'' These models often have an impact on the discrepancy in the amplitude of matter clustering, the ``$\sigma_8$-tension.'' To explore the interplay between the two tensions, we suggest a simple method to visualize the relation between the two parameters: $H_0$ and $\sigma_8$. For a given extension of the $\Lambda$CDM model and dataset, we plot the relation between $H_0$ and $\sigma_8$ for different amplitudes of the beyond-$\Lambda$CDM physics. In this work, we use this visualization method to illustrate the trend of selected cosmological models, including nonminimal Higgs-like inflation, early dark energy, a varying effective electron mass, an extra number of relativistic species and modified dark energy models. Although already studied in the literature, some of these models have not been analyzed in view of the two joint tensions. We stress that the method used here could be a useful diagnostic tool to illustrate the behavior of complex cosmological models with many parameters in the context of the $H_0$ and $\sigma_8$ tensions.
- [52] arXiv:2401.14331 (replaced) [pdf, ps, html, other]
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Title: Collapsing Domain Wall Networks: Impact on Pulsar Timing Arrays and Primordial Black HolesComments: 15 pages, 13 figures, minor additions, version to appear on JCAPSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
Unstable domain wall (DW) networks in the early universe are cosmologically viable and can emit a large amount of gravitational waves (GW) before annihilating. As such, they provide an interpretation for the recent signal reported by Pulsar Timing Array (PTA) collaborations. A related important question is whether such a scenario also leads to significant production of Primordial Black Holes (PBH). We investigate both GW and PBH production using 3D numerical simulations in an expanding background, with box sizes up to $N=3240$, including the annihilation phase. We find that: i) the network decays exponentially, i.e. the false vacuum volume drops as $\sim \exp(-\eta^3)$, with $\eta$ the conformal time; ii) the GW spectrum is larger than traditional estimates by more than one order of magnitude, due to a delay between DW annihilation and the sourcing of GWs. We then present a novel semi-analytical method to estimate the PBH abundances: rare false vacuum pockets of super-Hubble size collapse to PBHs if their energy density becomes comparable to the background when they cross the Hubble scale. Smaller (but more abundant) pockets will instead collapse only if they are close to spherical. This introduces very large uncertainties in the final PBH abundance. The first phenomenological implication is that the DW interpretation of the PTA signal is compatible with observational constraints on PBHs, within the uncertainties. Second, in a different parameter region, the dark matter can be entirely in the form of asteroid-mass PBHs from the DW collapse. Remarkably, this would also lead to a GW background in the observable range of LIGO-Virgo-KAGRA and future interferometers, such as LISA and Einstein Telescope.
- [53] arXiv:2401.17262 (replaced) [pdf, ps, html, other]
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Title: Post-inflationary Leptogenesis and Dark Matter production: Metric versus Palatini formalismComments: 47 pages, 15 figures, accepted in JHEP with minor revisionsSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
We investigate production of non-thermal dark matter particles and heavy sterile neutrinos from inflaton during the reheating era, which is preceded by a slow-roll inflationary epoch with a quartic potential and non-minimal coupling ($\xi$) between inflaton and gravity. We compare our analysis between metric and Palatini formalism. For the latter, the tensor-to-scalar ratio, r, decreases with $\xi$. We find that for $\xi=0.5$ and number of $e$-folds $\sim 60$, $r$ can be as small as $\sim {\cal O}\left(10^{-3}\right)$ which may be validated at future reaches of upcoming CMB observation such as CMB-S4 etc. We identify the permissible range of Yukawa coupling $y_\chi$ between inflaton and fermionic DM $\chi$, to be ${\cal O}\left(10^{-3.5}\right)\gtrsim y_\chi \gtrsim {\cal O}\left(10^{-20}\right)$ for metric formalism and ${\cal O}\left(10^{-4}\right)\gtrsim y_\chi \gtrsim {\cal O}\left(10^{-11}\right)$ for Palatini formalism which is consistent with current PLANCK data and also within the reach of future CMB experiments. For the scenario of leptogenesis via the decay of sterile neutrinos produced from inflaton decay, we also investigate the parameter space involving heavy neutrino mass $M_{N_1}$ and Yukawa coupling $y_{N_1}$ of sterile neutrino with inflaton, which are consistent with current CMB data and successful generation of the observed baryon asymmetry of the universe via leptogenesis. In contrast to metric formalism, in the case of Palatini formalism, for successful leptogenesis to occur, we find that $y_{N_1}$ has a very narrow allowable range and is severely constrained from the consistency with CMB predictions.
- [54] arXiv:2404.00181 (replaced) [pdf, ps, html, other]
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Title: Oscillations in the Dark?Luis A. Escamilla, Supriya Pan, Eleonora Di Valentino, Andronikos Paliathanasis, J. Alberto Vázquez, Weiqiang YangComments: 12 pages, 5 figures, 4 tablesSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
The main aim of this work is to use a model-independent approach, along with late-time observational probes, to reconstruct the dark energy (DE) equation of state $w_{\rm DE}(z)$. Our analysis showed that, for a late time universe, $w_{\rm DE}$ deviates from being a constant but in contrast exhibits an oscillatory behavior, hence both quintessence ($w_{\rm DE}> -1$) and phantom ($w_{\rm DE} < -1$) regimes are equally allowed. In order to portray this oscillatory behavior, we explored various parametrizations for the equation of state and identified the closest approximation based on the goodness of fit with the data and the Bayesian evidence analysis. Our findings indicated that while all considered oscillating DE parametrizations provided a better fit to the data, compared to the cosmological constant, they are penalized in the Bayesian evidence analysis due to the additional free parameters. Overall, the present article demonstrates that in the low redshift regime, the equation of state of the DE prefers to be dynamical and oscillating. We anticipate that future cosmological probes will take a stand in this direction.
- [55] arXiv:2405.07695 (replaced) [pdf, ps, html, other]
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Title: High-energy neutrinos from late-time jets of gamma-ray bursts seeded with cocoon photonsComments: 18 pages, 7 figures, and 1 table, submitted to ApJSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)
In gamma-ray bursts (GRBs), $\sim$ 100 - 1000 s after the prompt emission, afterglow observations have consistently shown X-ray excesses detected in the form of flares (XFs; in long GRBs) or extended emission (EEs; in short GRBs). These observations are interpreted as emissions from jets launched by late central engine activity. However, the characteristics of these late-time jets, particularly the dissipation radius ($r_{\rm diss}$), Lorentz factor ($\Gamma$), and cosmic-ray loading factor ($\xi_p$), remain unknown despite their importance. Here, in order to understand the properties of the late-time jets with future multi-messenger observations, we estimate the detectability of neutrinos associated with late-time emissions for a wide range of $r_{\rm diss}$ and $\Gamma$, assuming $\xi_p=10$. We take into account external seed photons from the cocoon around the jets, which can enhance the neutrino production through photohadronic interaction in the jet dissipation region. Our results are still consistent with the upper limit obtained by IceCube. Our calculations indicate a promising prospect for neutrino detection with IceCube-Gen2 through the stacking of $\sim 1000-2000$ events, for a wide range of $r_{\rm diss}$ and $\Gamma$. We found that setting an optimal energy threshold of 10 TeV can significantly reduce noise without negatively affecting neutrino detection. Furthermore, even in the case of non-detection, we show that meaningful constraints on the characteristics of the late-time jets can be obtained.