High Energy Physics - Experiment
- [1] arXiv:2405.09658 [pdf, ps, html, other]
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Title: Higgs and precision physics at CMSSpandan Mondal (on behalf of the CMS Collaboration)Comments: Contribution to the 2024 QCD session of the 58th Rencontres de MoriondSubjects: High Energy Physics - Experiment (hep-ex)
Since the discovery of the Higgs boson in 2012, significant progress has been made in measuring several properties related to the Higgs boson. The large dataset available now facilitates precise measurements of the Higgs boson mass, natural width, couplings, production cross sections, and even differential and fiducial cross sections. The latest precision measurements performed by the CMS experiment in the Higgs sector are presented in this note.
- [2] arXiv:2405.09910 [pdf, ps, html, other]
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Title: Performance testing of a novel short axis photomultiplier tube for the HUNT projectYijiang Peng, Zike Wang, Bo Gao, Yiyue Tang, Mingjun Chen, Kai Li, Ling Ren, Xiaohao You, Maoyuan LiuSubjects: High Energy Physics - Experiment (hep-ex); Instrumentation and Methods for Astrophysics (astro-ph.IM); Instrumentation and Detectors (physics.ins-det)
Photomultiplier tubes (PMTs) with large-area cathodes are increasingly being used in cosmic-ray experiments to enhance detection efficiency. The optical modules (OMs) of the High-Energy Underwater Neutrino Telescope (HUNT) have employed a brand new N6205 20-inch microchannel plate photomultiplier tube (MCP-PMT) developed by the North Night Vision Science & Technology (Nanjing) Research Institute Co. Ltd. (NNVT). In order to make the 20-inch PMT fit into the 23-inch diameter pressure-resistant glass sphere, NNVT improved the internal structure of PMT and shortened the height of PMT by more than 10~cm. The first batch of these PMTs has been delivered for preliminary research work. This paper describes a specific PMT testing platform built for the first batch of 15 MCP-PMTs, and some performance parameters of PMT, such as P/V ratio, TTS and nonliniearity, are measured.The measurement results show that the new PMT still has good performance and can meet the requirements of HUNT project.
- [3] arXiv:2405.09974 [pdf, ps, html, other]
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Title: Tau and low multiplicity physics at Belle and Belle IILuigi Corona (on behalf of the Belle II Collaboration)Journal-ref: Contribution to the 2024 Electroweak session of the 58th Rencontres de MoriondSubjects: High Energy Physics - Experiment (hep-ex)
The Belle and Belle II experiments have collected a 1.4 ab$^{-1}$ sample of $e^+e^-$ collision data at centre-of-mass energies near the $\Upsilon (nS)$ resonances, of which 424 fb$^{-1}$ were collected at Belle II in Run1 (2019--2022). We present a measurement of the lepton-flavour universality between electrons and muons, the search for the lepton-flavour violation decay $\tau^{-} \to \mu^{-}\mu^{+}\mu^{-}$, and a measurement of the $e^+e^- \to \pi^+\pi^-\pi^0$ cross section in the energy range from 0.62--3.5 GeV using an initial-state radiation technique, all performed with Belle II data.
- [4] arXiv:2405.10106 [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.
- [5] arXiv:2405.10261 [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.
New submissions for Friday, 17 May 2024 (showing 5 of 5 entries )
- [6] arXiv:2405.09625 (cross-list from hep-ph) [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.
- [7] arXiv:2405.09650 (cross-list from hep-ph) [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.
- [8] arXiv:2405.09912 (cross-list from physics.plasm-ph) [pdf, ps, html, other]
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Title: Driver at 10 MJ and 1 shot per 30 minutes for inertial confinement fusion at high gain: efficient, compact, low laser-plasma instabilities, multi-color, low-cost, applicable to multiple fusion schemesSubjects: Plasma Physics (physics.plasm-ph); High Energy Physics - Experiment (hep-ex)
The ignition at the National Ignition Facility (NIF) set off a global wave of research on the inertial fusion energy (IFE). However, IFE requires a necessary target gain G of 30-100, while it is hard to achieve the fusions at such high gain with the energy, configuration, and technical route of the NIF. We will present a conceptual design for the next generation laser driver of 10 MJ, 2~3 PW at the laser wavelength of 0.353 micrometer (or 0.353 micrometer, then the energy and power can be higher), and 1 shot per 30 minutes, which is efficient, compact, low-cost, low laser-plasma instabilities, applicable to multiple laser fusion schemes, and aiming for G > 30.
- [9] arXiv:2405.09994 (cross-list from hep-ph) [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.
- [10] arXiv:2405.10056 (cross-list from hep-ph) [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.
- [11] arXiv:2405.10111 (cross-list from hep-ph) [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 (cross-list from hep-ph) [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.
Cross submissions for Friday, 17 May 2024 (showing 7 of 7 entries )
- [13] arXiv:2312.13945 (replaced) [pdf, ps, html, other]
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Title: First search for dark-trident processes using the MicroBooNE detectorMicroBooNE collaboration: P. Abratenko, O. Alterkait, D. Andrade Aldana, L. Arellano, J. Asaadi, A. Ashkenazi, S. Balasubramanian, B. Baller, G. Barr, D. Barrow, J. Barrow, V. Basque, O. Benevides Rodrigues, S. Berkman, A. Bhanderi, A. Bhat, M. Bhattacharya, M. Bishai, A. Blake, B. Bogart, T. Bolton, J.Y. Book, M.B. Brunetti, L. Camilleri, Y. Cao, D. Caratelli, F. Cavanna, G. Cerati, A. Chappell, Y. Chen, J.M. Conrad, M. Convery, L. Cooper-Troendle, J.I. Crespo-Anadon, R. Cross, M. Del Tutto, S.R. Dennis, P. Detje, A. Devitt, R. Diurba, Z. Djurcic, R. Dorrill, K. Duffy, S. Dytman, B. Eberly, P. Englezos, A. Ereditato, J.J. Evans, R. Fine, O.G. Finnerud, B.T. Fleming, W. Foreman, D. Franco, A.P. Furmanski, F. Gao, D. Garcia-Gamez, S. Gardiner, G. Ge, S. Gollapinni, E. Gramellini, P. Green, H. Greenlee, L. Gu, W. Gu, R. Guenette, P. Guzowski, L. Hagaman, O. Hen, C. Hilgenberg, G.A. Horton-Smith, Z. Imani, B. Irwin, M.S. Ismail, C. James, X. Ji, J.H. Jo, R.A. Johnson, Y.J. Jwa, D. Kalra, N. Kamp, G. Karagiorgi, W. Ketchum, M. Kirby, T. Kobilarcik, I. Kreslo, M. B. Leibovitch, I. Lepetic, J.-Y. Li, K. Li, Y. Li, K. Lin, B.R. Littlejohn, H. Liu, W.C. Louis, X. Luo, C. Mariani, D. Marsden, J. Marshall, N. MartinezSubjects: High Energy Physics - Experiment (hep-ex)
We present a first search for dark-trident scattering in a neutrino beam using a data set corresponding to $7.2 \times 10^{20}$ protons on target taken with the MicroBooNE detector at Fermilab. Proton interactions in the neutrino target at the Main Injector produce $\pi^0$ and $\eta$ mesons, which could decay into dark-matter (DM) particles mediated via a dark photon $A^\prime$. A convolutional neural network is trained to identify interactions of the DM particles in the liquid-argon time projection chamber (LArTPC) exploiting its image-like reconstruction capability. In the absence of a DM signal, we provide limits at the $90\%$ confidence level on the squared kinematic mixing parameter $\varepsilon^2$ as a function of the dark-photon mass in the range $10\le M_{A^\prime}\le 400$ MeV. The limits cover previously unconstrained parameter space for the production of fermion or scalar DM particles $\chi$ for two benchmark models with mass ratios $M_{\chi}/M_{A^\prime}=0.6$ and $2$ and for dark fine-structure constants $0.1\le\alpha_D\le 1$.
- [14] 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.
- [15] 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.
- [16] 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.
- [17] arXiv:2311.09985 (replaced) [pdf, ps, html, other]
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Title: Measurement of forward charged hadron flow harmonics in peripheral PbPb collisions at $\sqrt{s_{NN}}=5.02$ TeV with the LHCb detectorLHCb collaboration: R. Aaij, A.S.W. Abdelmotteleb, C. Abellan Beteta, F. Abudinén, T. Ackernley, B. Adeva, M. Adinolfi, P. Adlarson, C. Agapopoulou, C.A. Aidala, Z. Ajaltouni, S. Akar, K. Akiba, P. Albicocco, J. Albrecht, F. Alessio, M. Alexander, A. Alfonso Albero, Z. Aliouche, P. Alvarez Cartelle, R. Amalric, S. Amato, J.L. Amey, Y. Amhis, L. An, L. Anderlini, M. Andersson, A. Andreianov, P. Andreola, M. Andreotti, D. Andreou, A. Anelli, D. Ao, F. Archilli, M. Argenton, S. Arguedas Cuendis, A. Artamonov, M. Artuso, E. Aslanides, M. Atzeni, B. Audurier, D. Bacher, I. Bachiller Perea, S. Bachmann, M. Bachmayer, J.J. Back, A. Bailly-reyre, P. Baladron Rodriguez, V. Balagura, W. Baldini, J. Baptista de Souza Leite, M. Barbetti, I. R. Barbosa, R.J. Barlow, S. Barsuk, W. Barter, M. Bartolini, F. Baryshnikov, J.M. Basels, G. Bassi, B. Batsukh, A. Battig, A. Bay, A. Beck, M. Becker, F. Bedeschi, I.B. Bediaga, A. Beiter, S. Belin, V. Bellee, K. Belous, I. Belov, I. Belyaev, G. Benane, G. Bencivenni, E. Ben-Haim, A. Berezhnoy, R. Bernet, S. Bernet Andres, H.C. Bernstein, C. Bertella, A. Bertolin, C. Betancourt, F. Betti, J. Bex, Ia. Bezshyiko, J. Bhom, M.S. Bieker, N.V. Biesuz, P. Billoir, A. Biolchini, M. Birch, F.C.R. Bishop, A. Bitadze, A. Bizzeti, M.P. Blago, T. Blake, F. Blanc, J.E. BlankComments: All figures and tables, along with any supplementary material and additional information, are available at this https URL (LHCb public pages)Journal-ref: Phys. Rev. C 109 (2024) 054908Subjects: Nuclear Experiment (nucl-ex); High Energy Physics - Experiment (hep-ex)
Flow harmonic coefficients, $v_n$, which are the key to studying the hydrodynamics of the quark-gluon plasma (QGP) created in heavy-ion collisions, have been measured in various collision systems and kinematic regions and using various particle species. The study of flow harmonics in a wide pseudorapidity range is particularly valuable to understand the temperature dependence of the shear viscosity to entropy density ratio of the QGP. This paper presents the first LHCb results of the second- and the third-order flow harmonic coefficients of charged hadrons as a function of transverse momentum in the forward region, corresponding to pseudorapidities between 2.0 and 4.9, using the data collected from PbPb collisions in 2018 at a center-of-mass energy of $5.02$ TeV. The coefficients measured using the two-particle angular correlation analysis method are smaller than the central-pseudorapidity measurements at ALICE and ATLAS from the same collision system but share similar features.
- [18] 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.
- [19] arXiv:2312.06572 (replaced) [pdf, ps, html, other]
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Title: Evidence for an excess of charged over neutral $K$ meson production in high-energy collisions of atomic nucleiNA61/SHINE Collaboration: H. Adhikary, P. Adrich, K.K. Allison, N. Amin, E.V. Andronov, I.-C. Arsene, M. Bajda, Y. Balkova, D. Battaglia, A. Bazgir, S. Bhosale, M. Bielewicz, A. Blondel, M. Bogomilov, Y. Bondar, A. Brandin, W. Brylinski, J. Brzychczyk, M. Buryakov, A.F. Camino, M. Cirkovic, M. Csanád, J. Cybowska, T. Czopowicz, C. Dalmazzone, N. Davis, A. Dmitriev, P. von Doetinchem, W. Dominik, J. Dumarchez, R. Engel, G.A. Feofilov, L. Fields, Z. Fodor, M. Friend, M. Gazdzicki, O. Golosov, V. Golovatyuk, M. Golubeva, K. Grebieszkow, F. Guber, S.N. Igolkin, S. Ilieva, A. Ivashkin, A. Izvestnyy, N. Kargin, N. Karpushkin, E. Kashirin, M. Kiełbowicz, V.A. Kireyeu, R. Kolesnikov, D. Kolev, Y. Koshio, V.N. Kovalenko, S. Kowalski, B. Kozłowski, A. Krasnoperov, W. Kucewicz, M. Kuchowicz, M. Kuich, A. Kurepin, A. László, M. Lewicki, G. Lykasov, V.V. Lyubushkin, M. Mackowiak-Pawłowska, Z. Majka, A. Makhnev, B. Maksiak, A.I. Malakhov, A. Marcinek, A.D. Marino, H.-J. Mathes, T. Matulewicz, V. Matveev, G.L. Melkumov, A. Merzlaya, Ł. Mik, S. Morozov, Y. Nagai, T. Nakadaira, M. Naskret, S. Nishimori, A. Olivier, V. Ozvenchuk, O. Panova, V. Paolone, O. Petukhov, I. Pidhurskyi, R. Płaneta, P. Podlaski, B.A. Popov, B. Pórfy, D.S. Prokhorova, D. Pszczel, S. Puławski, J. Puzovic, R. Renfordt, L. RenComments: The paper includes updates based on the final results of $K^+$ and $K^-$ yields published in Eur. Phys. J.C 84 (2024) 4, 416Subjects: Nuclear Experiment (nucl-ex); High Energy Physics - Experiment (hep-ex)
Collisions of atomic nuclei at relativistic velocities produce new particles, predominantly mesons containing one valence quark and one valence anti-quark. These particles are produced in strong interactions, which preserve an approximate symmetry between up ($u$) and down ($d$) quarks. In the case of $K$ meson production, if this symmetry were exact, it would result in equal numbers of charged ($K^+$ and $K^-$) and neutral ($K^0$ and $\overline K^0$) mesons in the final state. In this Letter, we report a measurement of the relative abundance of charged over neutral $K$ meson production in collisions of argon and scandium nuclei at a center-of-mass energy of 11.9 GeV per nucleon pair. We find that production of $\mathit{K^+}$ and $\mathit{K^-}$ mesons at mid-rapidity is $(18.4\pm 6.1)\%$ higher than that of the neutral $K$ mesons. The origin of this unexpected excess remains to be elucidated.
- [20] 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.
- [21] 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.
- [22] 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.