Mon·Sep 5, 2022Monday·September 5, 2022

1. 01*

   Towards a UV-Model of Kinetic Mixing and Portal Matter II: Exploring Unification in an $SU(N)$ Group

   Thomas G. Rizzo🇺🇸

   If dark matter (DM) interacts with the Standard Model (SM) via the $U(1{)}_D$ kinetic mixing (KM) portal at low energies, it necessitates not only the existence of portal matter (PM) particles which carry both dark and SM quantum numbers, but also a possible UV completion into which this $U(1{)}_D$ and the SM are both embedded. In earlier work, following a bottom-up approach, we attempted to construct a more unified framework of these SM and dark sector interactions. In this paper we will instead begin to explore, from the top-down, the possibility of the unification of these forces via the decomposition of a GUT-like group, $G\to G_{SM}\times G_{Dark}$, where $U(1{)}_D$ is now a low energy diagonal subgroup of $G_{Dark}$ and where the familiar $G_{SM}=SU(5)$ will play the role of a proxy for the conventional $SU(3{)}_c\times SU(2{)}_L\times U(1{)}_Y$ SM gauge group. In particular, for this study it will be assumed that $G=SU(N)$ with $N=6-10$. Although not our main goal, models that also unify the three SM generational structure within this same general framework will also be examined. The possibilities are found to be quite highly constrained by our chosen set of model building requirements which are likely too strong when they are employed simultaneously to obtain a successful model framework.

   hep-phPRD(2022)·20 citations
2. 02*

   Axial transition form factors of octet baryons in the perturbative chiral quark model

   X. Y. Liu🇹🇭 · A. Limphirat🇹🇭 · K. Xu🇹🇭 · Z. Zhao🇹🇭 · K. Khosonthongkee🇹🇭 · Y. Yan🇹🇭

   We study the axial transition form factors $G_A^{B\to B^{\prime }}(Q^2)$ as well as the axial charges $g_A^{B\to B^{\prime }}$ of the octet baryons in the perturbative chiral quark model~(PCQM) with including both the ground and excited states in the intermediate quark propagators. The PCQM results on the $G_A^{B\to B^{\prime }}(Q^2)$ and the $g_A^{B\to B^{\prime }}$ are found in good agreement with the existing experimental data and the lattice-QCD values. The study figures out that the $G_A^{B\to B^{\prime }}(Q^2)$ for all transitions behave in the dipolelike form, which is dominantly caused by the three-quark core. The meson cloud with the ground-state quark propagator also plays an extremely important role but results in a flat contribution. The excited-state quark propagator contributing to the $G_A^{B\to B^{\prime }}(Q^2)$ could be regarded as the higher order correction and it is very limited.

   hep-phPRD(2023)·6 citations
3. 03*

   Accelerating LHC event generation with simplified pilot runs and fast PDFs

   Enrico Bothmann🇩🇪 · Andy Buckley🇬🇧 · Ilektra A. Christidi🇬🇧 · Christian Gütschow🇬🇧 · Stefan Höche🇺🇸 · Max Knobbe🇩🇪 · Tim Martin🇬🇧 · Marek Schönherr🇬🇧

   Poor computing efficiency of precision event generators for LHC physics has become a bottleneck for Monte-Carlo event simulation campaigns. We provide solutions to this problem by focusing on two major components of general-purpose event generators: The PDF evaluator and the matrix-element generator. For a typical production setup in the ATLAS experiment, we show that the two can consume about 80% of the total runtime. Using NLO simulations of $pp\to {\ell }^{+}{\ell }^{-}+\text{jets}$ and $pp\to t\bar{t}+\text{jets}$ as an example, we demonstrate that the computing footprint of LHAPDF and Sherpa can be reduced by factors of order 10, while maintaining the formal accuracy of the event sample. The improved codes are made publicly available.

   hep-phEPJC(2022)·33 citations
4. 04*

   Gallium Anomaly: Critical View from the Global Picture of ${\nu }_e$ and ${\bar{\nu }}_e$ Disappearance

   C. Giunti🇮🇹 · Y.F. Li🇨🇳 · C.A. Ternes🇮🇹 · O. Tyagi🇮🇹 · Z.Xin🇨🇳

   The significance of the Gallium Anomaly, from the BEST, GALLEX, and SAGE radioactive source experiments, is quantified using different theoretical calculations of the neutrino detection cross section, and its explanation due to neutrino oscillations is compared with the bounds from the analyses of reactor rate and spectral ratio data, $\beta$-decay data, and solar neutrino data. In the 3+1 active-sterile neutrino mixing scheme, the Gallium Anomaly is in strong tension with the individual and combined bounds of these data sets. In the combined scenario with all available data, the parameter goodness of fit is below 0.042%, corresponding to a severe tension of 4-5$\sigma$, or stronger. Therefore, we conclude that one should pursue other possible solutions beyond short-baseline oscillations for the Gallium Anomaly. We also present a new global fit of ${\nu }_e$ and ${\bar{\nu }}_e$ disappearance data, showing that there is a 2.6-3.3$\sigma$ preference in favor of short-baseline oscillations, which is driven by an updated analysis of reactor spectral ratio data.

   hep-phhep-exJHEP(2022)·58 citations
5. 05*

   Sivers, Boer-Mulders and worm-gear distributions at next-to-leading order

   Felix Rein🇩🇪 · Simone Rodini🇩🇪 · Andreas Schäfer🇩🇪 · Alexey Vladimirov🇪🇸

   We compute the Sivers, Boer-Mulders, worm-gear (T and L) transverse momentum dependent distributions in terms of twist-two and twist-three collinear distributions in the small-b limit up to next-to-leading order (NLO) in perturbation theory.

   hep-phhep-thJHEP(2023)·23 citations
6. 06*

   Jet modification in absence of QGP-medium: the role of multiparton interactions and color reconnection

   Prottoy Das🇮🇳 · Abhi Modak🇮🇳 · Debjani Banerjee🇮🇳 · Rathijit Biswas🇨🇳 · Supriya Das🇮🇳 · Sanjay K. Ghosh🇮🇳 · Sibaji Raha🇮🇳 · Sidharth Kumar Prasad🇮🇳

   Recent studies of high-multiplicity events in small collision systems (proton-proton and proton-lead) have drawn research interest towards the possibility of the formation of partonic medium in such systems. One of the important consequences of the formation of dense partonic medium is quenching of high-momentum final-state particles resulting in several experimental observations such as suppression in nuclear modification factor $R_{\mathrm{AA}}$, modification of jet shape observable $\rho (r)$ and jet fragmentation ($z^{\mathrm{ch}}$) distributions, etc. In this work, we study $\rho (r)$ and $z^{\mathrm{ch}}$ for inclusive charged-particle jets in proton-proton (pp) collisions at $\sqrt{s}$~=~13~TeV using PYTHIA~8 Monash~2013 Monte Carlo simulation. We show that the color reconnection (CR) and multiparton interaction (MPI) mechanisms in PYTHIA~8 can lead to an increased rate of jet production. We also find that the mechanisms of MPI and CR and change in the gluonic contribution in high-multiplicity events result in significant modification of $\rho (r)$ and $z^{\mathrm{ch}}$ compared to those in minimum bias events for 10~$<p_{\mathrm{T},\mathrm{jet}}^{\mathrm{ch}}<$~20~GeV/$c$. We notice a direct connection of $⟨N_{\mathrm{MPI}}⟩$ and gluonic contribution with the amount of modification in $\rho (r)$ -- the larger the number of MPIs and/or gluonic contribution, the larger the amount of modification of $\rho (r)$.

   hep-phnucl-thCPC(2024)·4 citations
7. 07*

   Comments on low mass dissociation at the LHC in the context of the discrepancy between the ATLAS and TOTEM measurements of ${\sigma }_{tot}$

   Per Grafstrom🇮🇹

   The cross section for low mass dissociation at LHC energies is estimated in a partly data driven approach. The result is compared to the Monte Carlo estimate from the QGSJET-II-03 model used by the TOTEM experiment in the determination of ${\sigma }_{tot}$ via the luminosity-independent method. Significant differences are found and possible consequences are explored and discussed.

   hep-phhep-ex3 citations
8. 08*

   Production of $D_{s0}^{\ast }(2317)$ and $D_{s1}(2460)$ in $B$ decays as $D^{(\ast )}K$ and $D_s^{(\ast )}\eta$ molecules

   Ming-Zhu Liu🇨🇳 · Xi-Zhe Ling🇨🇳 · Li-Sheng Geng🇨🇳 · En-Wang🇨🇳 · Ju-Jun Xie🇨🇳

   The molecular nature of $D_{s0}^{\ast }(2317)$ and $D_{s1}(2460)$ have been extensively studied from the perspective of their masses, decay properties, and production rates. In this work, we study the weak decays of $B\to {\bar{D}}^{(\ast )}{D}_{s0}^{\ast }(2317)$ and $B\to {\bar{D}}^{(\ast )}{D}_{s1}(2460)$ by invoking triangle diagrams where the $B$ meson first decays weakly into ${\bar{D}}^{(\ast )}{D}_s^{(\ast )}$ and $J/\psi K$(${\eta }_{c}K$), and then the $D_{s0}^{\ast }(2317)$ and $D_{s1}(2460)$ are dynamically generated by the final-state interactions of $D_s^{(\ast )}\eta$ and $D^{(\ast )}K$ via exchanges of $\eta$ and $D^{(\ast )}$ mesons. The obtained absolute branching fractions of Br$[B\to {\bar{D}}^{(\ast )}{D}_{s0}^{\ast }(2317)]$ are in reasonable agreement with the experimental data, while the branching fractions of Br$[B\to {\bar{D}}^{(\ast )}{D}_{s1}(2460)]$ are smaller than the experimental central values by almost a factor of two to three. We tentatively attribute such a discrepancy to either reaction mechanisms missing in the present work or the likely existence of a relatively larger $c\bar{s}$ component in the $D_{s1}(2460)$ wave function.

   hep-phhep-exPRD(2022)·36 citations
9. 09*

   Statistical analysis of initial state and final state response in heavy-ion collisions

   Nicolas Borghini🇩🇪 · Marc Borrell🇩🇪 · Nina Feld🇩🇪 · Hendrik Roch🇩🇪 · Sören Schlichting🇩🇪 · Clemens Werthmann🇩🇪

   We develop a general decomposition of an ensemble of initial density profiles in terms of an average state and a basis of modes that represent the event-by-event fluctuations of the initial state. The basis is determined such that the probability distributions of the amplitudes of different modes are uncorrelated. Based on this decomposition, we quantify the different types and probabilities of event-by-event fluctuations in Glauber and Saturation models and investigate how the various modes affect different characteristics of the initial state. We perform simulations of the dynamical evolution with KoMPoST and MUSIC to investigate the impact of the modes on final-state observables and their correlations.

   hep-phnucl-thPRC(2023)·26 citations
10. 10*

    $h\to {\rm Y}\gamma$ Decay: Smoking Gun Signature of Wrong-Sign $hb\bar{b}$ Coupling

    Aditya Batra🇮🇳 · Sanjoy Mandal🇰🇷 · Rahul Srivastava🇮🇳

    We perform a model-independent study of new physics effects in the Higgs decay $h\to {\rm Y}\gamma$, focusing on scenarios that spoil the accidental cancellation between the direct and indirect amplitudes. After imposing all existing constraints from Higgs production and decay measurements, we find that a wrong-sign $hb\bar{b}$ coupling is the only viable scenario capable of enhancing the $h\to {\rm Y}\gamma$ decay width by nearly two orders of magnitude. Therefore, an observation of a significantly enhanced $h\to {\rm Y}\gamma$ rate at the LHC or future colliders would provide unambiguous evidence for a wrong-sign $hb\bar{b}$ coupling, directly pointing to the presence of an extended Higgs sector.

    hep-phhep-ex7 citations
11. 11*

    Accessing CKM suppressed top decays at the LHC

    Darius A. Faroughy🇨🇭 · Jernej F. Kamenik🇸🇮 · Manuel Szewc🇸🇮 · Jure Zupan🇺🇸

    We propose an extension of the existing experimental strategy for measuring branching fractions of top quark decays, targeting specifically $t\to j_{q}W$, where $j_q$ is a light quark jet. The improved strategy uses orthogonal $b$- and $q$-taggers, and adds a new observable, the number of light-quark-tagged jets, to the already commonly used observable, the fraction of $b$-tagged jets in an event. Careful inclusion of the additional complementary observable significantly increases the expected statistical power of the analysis, with the possibility of excluding $|V_{tb}|=1$ at $95\%$ C.L. at the HL-LHC, and accessing directly the standard model value of $|V_{td}{|}^2+|V_{ts}{|}^2$.

    hep-phhep-exSciPost Phys.(2024)·10 citations
12. 12*

    Bosonic and Fermionic Holographic Fluctuation and Dissipation at finite temperature and density

    Nathan G. Caldeira🇧🇷 · Carlos A. D. Zarro🇧🇷 · Henrique Boschi-Filho🇧🇷

    In this paper we investigate some general aspects of fluctuation and dissipation in the holographic scenario at zero and finite density. We model this situation with a probe string in a diagonal metric representing a black brane. The string stretches from the black brane to a probe brane thus simulating a stochastic driven particle. In this scenario, we compute the admittance, the diffusion coefficient, the correlation functions and the regularized mean square displacement, for bosons and fermions, all from the metric components. We check these calculations with the fluctuation-dissipation theorem. Further, we show that at finite temperature and density, the mean square displacement in the limit of short times reproduces the usual quadratic (ballistic) behavior, for bosons and fermions. For large times, we find ultraslow diffusive processes in various cases, except for bosons at zero chemical potential. We apply this general analysis in two different models: hyperscaling violation at finite temperature and a charged dilatonic AdS black hole, both for bosons and fermions. This is important because we found the fermionic diffusion in systems which allow the appearance of Fermi surfaces and Fermi liquids.

    ↳ hep-thcond-mat.otherhep-phPRD(2024)·2 citations
13. 13*

    Holographic cold dense matter constrained by neutron stars

    Lin Zhang🇨🇳 · Mei Huang🇨🇳

    The equation of state (EoS) for cold dense matter inside neutron stars is investigated by using holographic QCD models in the framework of the Einstein-Maxwell-dilaton (EMD) system and the improved Karch-Katz-Son-Stephanov (KKSS) action for matter part. This method of describing holographic nuclear matter in the EMD$+$KKSS framework is different from that by using the Dirac-Born-Infeld (DBI) action and the Chern-Simons (CS) terms. Combining with the Hebeler-Lattimer-Pethick-Schwenk (HLPS) intermediate equation of state (EoS), the hybrid EoS inside the neutron stars is constructed. The obtained hybrid EoS is located in the range that is defined by the low-density chiral effective theory, the high-density perturbative QCD, and the polytropic interpolations between them, and is constrained by the astrophysics observations. The square of the sound velocity reaches a maximum value larger than $0.8$ in the region of $2-5$ times the saturation baryon number density and approaches the conformal limit at the high baryon density range. The mass-radius relation and the tidal deformability of the neutron stars are in agreement with astrophysical measurements. The possible maximum mass for the neutron star is about $2.5M_{\odot }$ and the radius is about $12\mathrm{km}$ then. It is noticed that the holographic quark matter branch in the mass-radius relation is always unstable and the holographic nuclear matter can produce a stable branch. These results indicate that even in the core of the NS, the matter is still in the confinement phase and the quark matter is not favored.

    ↳ nucl-thastro-ph.HEhep-phPRD(2022)·22 citations
14. 14*

    Exotic Dark Matter Search with CDEX-10 Experiment at China's Jinping Underground Laboratory

    W. H. Dai🇨🇳 · L. P. Jia🇨🇳 · H. Ma🇨🇳 · Q. Yue🇨🇳 · K. J. Kang🇨🇳 · Y. J. Li🇨🇳 · H. P. An🇨🇳 · Greeshma C.🇹🇼 · J. P. Chang🇨🇳 · Y. H. Chen🇨🇳 · J. P. Cheng🇨🇳 · Z. Deng🇨🇳 and 72 other authors

    A search for exotic dark matter (DM) in the sub-GeV mass range has been conducted using 205 kg$\cdot$day data taken from a p-type point contact germanium detector of CDEX-10 experiment at China Jinping underground laboratory. New low-mass dark matter searching channels, neutral current fermionic DM absorption ($\chi +A\to \nu +A$) and DM-nucleus 3$\to$2 scattering ($\chi +\chi +A\to \varphi +A$), have been analyzed with an energy threshold of 160 eVee. No significant signal was found. Thus new limits on the DM-nucleon interaction cross section are set for both models at sub-GeV DM mass region. A cross section limit for the fermionic DM absorption is set to be $2.5\times 10^{-46}\mathrm{c}{\mathrm{m}}^2$(90\% C.L.) at DM mass of 10 MeV/c${}^2$. For the DM-nucleus 3$\to$2 scattering scenario, limits are extended to DM mass of 5 MeV/c${}^2$ and 14 MeV/c${}^2$ for the massless dark photon and bound DM final state, respectively.

    ↳ hep-exhep-phPRL(2022)·32 citations
15. 15*

    Dark Matter: DAMA/LIBRA and its perspectives

    R. Bernabei (1)🇮🇹 · P. Belli (1)🇮🇹 · F. Cappella (2)🇮🇹 · V. Caracciolo (1)🇮🇹 · R. Cerulli (1)🇮🇹 · C.J. Dai (3)🇨🇳 · A. d'Angelo (2)🇮🇹 · A. Incicchitti (2)🇮🇹 · A. Leoncini (1)🇮🇹 · X.H. Ma (3)🇨🇳 · V. Merlo (1)🇮🇹 · F. Montecchia (1,4)🇮🇹 · X.D. Sheng (3)🇨🇳 · Z.P. Ye (3,5) ((1) Univ. Roma Tor Vergata and INFN Roma Tor Vergata, (2) Univ. Roma and INFN Roma, (3) IHEP CAS Beijing, (4) Univ. Tor Vergata, (5) Univ. Jinggangshan)🇨🇳

    The long-standing model-independent annual modulation effect measured by DAMA deep underground at Gran Sasso Laboratory with different experimental configurations is summarized and perspectives will be highlighted. DAMA/LIBRA-phase2 set-up, $\simeq$ 250 kg highly radio-pure NaI(Tl) confirms the evidence of a signal that meets all the requirements of the model independent Dark Matter annual modulation signature at high C.L.; the full exposure is 2.86 ton $\times$ yr over 22 annual cycles. The experiment is currently collecting data in the DAMA/LIBRA-phase2 empowered configuration with an even lower software energy threshold. Other recent claims are shortly commented.

    ↳ hep-exastro-ph.COhep-phphysics.ins-detSciPost Phys.Proc.(2023)·20 citations
16. 16*

    Emission of gravitational waves by superconducting cosmic strings

    I. Yu. Rybak🇵🇹 · L. Sousa🇵🇹

    We study the gravitational radiation emission efficiency $\Gamma$ of superconducting cosmic strings. We demonstrate, by using a solvable model of transonic strings, that the presence of a current leads to a suppression of the gravitational emission of cusps, kinks and different types of loops. We also show that, when a current is present, the spectrum of emission of loops with cusps is exponentially suppressed as the harmonic mode increases, thus being significantly different from the power law spectrum of currentless loops. Furthermore, we establish a phenomenological relationship between $\Gamma$ and the value of the current on cosmic strings. We conjecture that this relation should be valid for an arbitrary type of current-carrying string. We use this result to study the potential impact of current on the stochastic gravitational wave background generated by cosmic strings with additional degrees of freedom and show that both the amplitude and shape of the spectrum may be significantly affected.

    ↳ gr-qcastro-ph.COhep-phJCAP(2022)·26 citations
17. 17*

    Machine Learning Post-Minkowskian Integrals

    Ryusuke Jinno🇪🇸 · Gregor Kälin🇩🇪 · Zhengwen Liu🇩🇪 · Henrique Rubira🇩🇪

    We study a neural network framework for the numerical evaluation of Feynman loop integrals that are fundamental building blocks for perturbative computations of physical observables in gauge and gravity theories. We show that such a machine learning approach improves the convergence of the Monte Carlo algorithm for high-precision evaluation of multi-dimensional integrals compared to traditional algorithms. In particular, we use a neural network to improve the importance sampling. For a set of representative integrals appearing in the computation of the conservative dynamics for a compact binary system in General Relativity, we perform a quantitative comparison between the Monte Carlo integrators VEGAS and i-flow, an integrator based on neural network sampling.

    ↳ hep-thgr-qchep-phJHEP(2023)·16 citations
18. 18*

    Early dark energy by dark Higgs, and axion-induced non-thermal trapping

    Shota Nakagawa🇯🇵 · Fuminobu Takahashi🇯🇵 · Wen Yin🇯🇵

    We propose a new scenario of early dark energy (EDE) with a dark Higgs trapped at the origin. To keep this dark Higgs trapped until around the matter-radiation equality, we use dark photons produced non-thermally by coherent oscillations of axions, which have a much stronger trapping effect than thermal mass. When the trapping ends, the dark Higgs quickly decays into dark photons, which are then red-shifted as radiation. The dark Higgs EDE scenario works well for an ordinary Mexican-hat potential, and the dark Higgs naturally sits at the origin from the beginning, since it is the symmetry-enhanced point. Thus, unlike the axion EDE, there is no need for elaborate potentials or fine-tuning with respect to the initial condition. Interestingly, the axion not only produces dark photons, but also explains dark matter. We find the viable parameter region of the axion decay constant and the axion mass where dark matter and the $H_0$ tension can be simultaneously explained. We also discuss the detectability of the axion in the presence of axion-photon coupling, and show that the axion can be the QCD axion.

    ↳ astro-ph.COhep-phPRD(2023)·26 citations
19. 19*

    Compact Binary Foreground Subtraction in Next-Generation Ground-Based Observatories

    Bei Zhou🇺🇸 · Luca Reali🇺🇸 · Emanuele Berti🇺🇸 · Mesut Çalışkan🇺🇸 · Cyril Creque-Sarbinowski🇺🇸 · Marc Kamionkowski🇺🇸 · B. S. Sathyaprakash🇺🇸

    The stochastic gravitational-wave backgrounds (SGWBs) for current detectors are dominated by binary black-hole (BBH) and binary neutron-star (BNS) coalescences. The sensitivity of current networks of gravitational-wave (GW) detectors allows only a small fraction of BBHs and BNSs to be resolved and subtracted, but previous work indicated that the situation should significantly improve with next-generation (XG) observatories. We revisit these conclusions by taking into account waveform-modeling uncertainties, updated astrophysical models, and (crucially) the full set of parameters that must be estimated to remove the resolved sources. Compared to previous studies, we find that the residual background from BBHs and BNSs is large even with XG detector networks. New data analysis methods will thus be required to observe the SGWB from cosmic supernovae or contributions from early-Universe phenomena like cosmic strings, stiff post-inflation fluids, or axion inflation.

    ↳ gr-qcastro-ph.HEhep-ph33 citations
20. 20*

    Superkicks and momentum density tests via micromanipulation

    Andrei Afanasev (George Washington Univ.)🇺🇸 · Carl E. Carlson (William & Mary)🇺🇸 · Asmita Mukherjee (I.I.T., Bombay)🇮🇳

    There is an unsettled problem in choosing the correct expressions for the local momentum density and angular momentum density of electromagnetic fields (or indeed, of any non-scalar field). If one only examines plane waves, the problem is moot, as the known possible expressions all give the same result. The momentum and angular momentum density expressions are generally obtained from the energy-momentum tensor, in turn obtained from a Lagrangian. The electrodynamic expressions obtained by the canonical procedure are not the same as the symmetric Belinfante reworking. For the interaction of matter with structured light, for example, twisted photons, this is important; there are drastically different predictions for forces and angular momenta induced on small test objects. We show situations where the two predictions can be checked, with numerical estimates of the size of the effects.

    ↳ physics.opticsgr-qchep-phquant-ph0 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.