Wed·Mar 2, 2022Wednesday·March 2, 2022

1. 01*

   QCD Analysis of $\Delta S=0$ Hadronic Parity Violation

   Susan Gardner🇺🇸 · Girish Muralidhara🇺🇸

   We present a QCD analysis of the effective weak Hamiltonian at hadronic energy scales for strangeness-nonchanging ($\Delta S=0$) hadronic processes. Performing a leading-order renormalization group analysis in QCD from the $W$ to the $\mathcal{O}(2\mathrm{GeV})$ energy scale, we derive the pertinent effective Hamiltonian for hadronic parity violation, including the effects of both neutral and charged weak currents. We compute the complete renormalization group evolution of all isosectors and the evolution through heavy-flavor thresholds for the first time. We show that the additional four-quark operators that enter below the $W$ mass scale from QCD operator mixing effects form a closed set, and they result in a $12\times 12$ anomalous dimension matrix. Computing the resulting effective Hamiltonian and comparing to earlier results, we affirm the importance of operator mixing effects and find, as an example, that the parity-violating pion-nucleon coupling constant, using the factorization Ansatz and an assessment of the pertinent quark charge of the nucleon in lattice QCD at the 2 GeV scale, is in better agreement with recent experiments.

   hep-phnucl-thPLB(2022)·9 citations
2. 02*

   Entanglement based tomography to probe new macroscopic forces

   Peter F. Barker🇬🇧 · Sougato Bose🇬🇧 · Ryan J. Marshman🇦🇺 · Anupam Mazumdar🇳🇱

   Quantum entanglement provides a novel way to test short distance physics in the non-relativistic regime. We will provide a protocol to {\it potentially} test new physics by bringing two charged massive particle interferometers adjacent to each other. Being charged, the two superpositions will be entangled via electromagnetic interactions mediated by the photons, including the Coulomb and the Casimir-Polder potential. We will bring a method of {\it entanglement based tomography} to seek time evolution of very small entanglement phases to probe new physical effects mediated by {\it hitherto unknown macroscopic force} which might be responsible for entangling the two charged superpositions modelled by the Yukawa type potential. We will be able to constrain the Yukawa couplings $\alpha \ge 10^{-35}$ for $r\ge 10^{-6}$m for new physics occurring in the electromagnetic sector, and in the gravitational potential ${\alpha }_g\ge 10^{-8}$ for $r\ge 10^{-6}$m. Furthermore, our protocol can also constrain the axion like particle mass and coupling, which is complimentary to the existing experimental bounds.

   hep-phgr-qcquant-phPRD(2022)·40 citations
3. 03*

   Differentiable Matrix Elements with MadJax

   Lukas Heinrich🇩🇪 · Michael Kagan🇺🇸

   MadJax is a tool for generating and evaluating differentiable matrix elements of high energy scattering processes. As such, it is a step towards a differentiable programming paradigm in high energy physics that facilitates the incorporation of high energy physics domain knowledge, encoded in simulation software, into gradient based learning and optimization pipelines. MadJax comprises two components: (a) a plugin to the general purpose matrix element generator MadGraph that integrates matrix element and phase space sampling code with the JAX differentiable programming framework, and (b) a standalone wrapping API for accessing the matrix element code and its gradients, which are computed with automatic differentiation. The MadJax implementation and example applications of simulation based inference and normalizing flow based matrix element modeling, with capabilities enabled uniquely with differentiable matrix elements, are presented.

   hep-phcs.LGphysics.comp-phphysics.data-anJ.Phys.Conf.Ser.(2023)·30 citations
4. 04*

   Functional reduction of one-loop Feynman integrals with arbitrary masses

   O.V. Tarasov🇷🇺

   A method of functional reduction for the dimensionally regularized one-loop Feynman integrals with massive propagators is described in detail. The method is based on a repeated application of the functional relations proposed by the author. Explicit formulae are given for reducing one-loop scalar integrals to a simpler ones, the arguments of which are the ratios of polynomials in the masses and kinematic invariants. We show that a general scalar $n$-point integral, depending on $n(n+1)/2$ generic masses and kinematic variables, can be expressed as a linear combination of integrals depending only on $n$ variables. The latter integrals are given explicitly in terms of hypergeometric functions of $(n-1)$ dimensionless variables. Analytic expressions for the 2-, 3- and 4-point integrals, that depend on the minimal number of variables, were also obtained by solving the dimensional recurrence relations. The resulting expressions for these integrals are given in terms of Gauss' hypergeometric function ${}_2{F}_1$, the Appell function $F_1$ and the hypergeometric Lauricella - Saran function $F_S$. A modification of the functional reduction procedure for some special values of kinematical variables is considered.

   hep-phJHEP(2022)·14 citations
5. 05*

   Aspects of $Z_{cs}(3985)$ and $Z_{cs}(4000)$

   Shuai Han🇨🇳 · Li-Ye Xiao🇨🇳

   In the present work we investigate the ${\eta }_{c}K$, $J/\psi K$, ${\eta }_c{K}^{\ast }$ and $J/\psi K^{\ast }$ hidden-charm decay modes for the $c\bar{c}s\bar{u}$ four-quark system in the molecular and compact tetraquark scenarios using the quark-exchange model. Our theoretical results indicate that if the newly observed states $Z_{cs}(3985)$ and $Z_{cs}(4000)$ are two different states, $Z_{cs}(4000)$ may be interpreted as the mixture $\frac{1}{\sqrt{2}}(D^0{D}_s^{\ast -}+D^{\ast 0}{D}_s^{-})$ of which the $J/\psi K$ partial decay width is about $\Gamma \sim 2.89$ MeV, while $Z_{cs}(3985)$ may be explained as the mixture $\frac{1}{\sqrt{2}}(-D^0{D}_s^{\ast -}+D^{\ast 0}{D}_s^{-})$ of which the $J/\psi K$ partial decay width is small to zero. Moreover, if the state $Z_{cs}(4000)$ can be explained as the mixed state $\frac{1}{\sqrt{2}}(D^0{D}_s^{\ast -}+D^{\ast 0}{D}_s^{-})$ indeed, the partial decay width ratio between $J/\psi K$ and ${\eta }_c{K}^{\ast }$ is close to unit, which indicates the decay channel ${\eta }_c{K}^{\ast }$ may be a ideal channel as well to decode the inner structure of $Z_{cs}(4000)$. In addition, the partial decay width for the tensor molecular state $|D^{\ast 0}{D}_s^{\ast -}{⟩}_{2^{+}}$ decaying into $J/\psi K^{\ast }$ can reach up to a few MeV, which shows this tensor molecular state has a good potential to be observed in this decay channel.

   hep-phPRD(2022)·22 citations
6. 06*

   Topological susceptibility and fourth cumulant in a uniform magnetic field

   Prabal Adhikari🇺🇸

   We study the topological susceptibility and fourth cumulant of the QCD vacuum in a background magnetic field using three-flavor chiral perturbation theory ($\chi$PT) for arbitrary quark masses and $n$-flavor $\chi$PT with degenerate quark masses. We find that the enhancement of the topological susceptibility is larger in the three-flavor $\chi$PT compared to two-flavor $\chi$PT. Additionally, in comparing the fourth cumulant, we find that its suppression is comparable for magnetic fields, $eH\lesssim 0.8m_{\pi }^2$, and weaker for larger magnetic fields in three-flavor $\chi$PT with its enhancement beginning at a significantly lower critical magnetic field compared to two-flavor $\chi$PT. We also find that the enhancement of the topological susceptibility in $n$-flavor $\chi$PT with degenerate quarks is significantly larger and the suppression of the topological cumulant significantly greater at weak fields with the critical magnetic field pushed out to larger magnetic fields compared to both two and three-flavor $\chi$PT.

   hep-phhep-thNPB(2022)·4 citations
7. 07*

   Impact of the interference between the resonance and continuum amplitudes on vector quarkonia decay branching fraction measurements

   Y. P. Guo🇨🇳 · C. Z. Yuan🇨🇳

   The measurement of the branching fraction of a heavy quarkonium decaying into light hadronic final state at $e^{+}{e}^{-}$ colliders is revisited. In $e^{+}{e}^{-}$ annihilation experiments, background contributions from the continuum amplitude and its interference with the resonance amplitude are irreducible. These effects become more and more significant as the precision of experimental measurements improves. While the former can be easily subtracted with data taken off the resonance peak, the latter depends on the relative size and phase between the resonance and continuum amplitudes. Two ratios are defined to estimate the size of these effects, $r_R^f$ for the ratio of the contribution of the interference term to the resonance term and $r_c^f$ for that to the continuum term. We find that $r_R^f$ could be as large as a few percent for narrow resonances, and both $r_R^f$ and $r_c^f$ could be large for broad resonances. This indicates that the interference effect is crucial for the measurements of the branching fractions aiming at the percent level or better precision and needs to be measured or estimated properly.

   hep-phhep-exPRD(2022)·19 citations
8. 08*

   Energy evolution of T-odd gluon TMDs at small $x$

   Daniël Boer🇳🇱 · Yoshikazu Hagiwara🇨🇳 · Jian Zhou🇨🇳 · Ya-jin Zhou🇨🇳

   We study the energy or TMD evolution of the three leading twist dipole type T-odd gluon TMDs inside a transversely polarized nucleon, all of which at small $x$ dynamically originate from the spin dependent odderon. Their energy dependence presents a unique opportunity to study the polarization dependent TMD evolution in the small-$x$ region, where the distributions are identical up to a normalization constant at tree level. We further propose to study their evolution via azimuthal asymmetries in virtual photon-jet production in polarized proton-proton collisions at RHIC. We present model predictions for the asymmetries as functions of the large jet or photon transverse momentum and $Q^2$ which set the hard scales in this process.

   hep-phPRD(2022)·17 citations
9. 09*

   Lack of evidence for an odderon at small t

   A Donnachie🇬🇧 · P V Landshoff🇬🇧

   It is fundamental that the phase of an elastic scattering amplitude is related to its energy variation. We repeat a previous fit to proton-proton and proton-antiproton elastic scattering data from 13 to 13000 GeV, taking better account of the very high accuracy of the 13 TeV data. The conclusion remains that there is no evidence for the existence of an odderon in the small-t data

   hep-phhep-exPLB(2022)·15 citations
10. 10*

    Statistical properties of partonic configurations and diffractive dissociation in high-energy electron-nucleus scattering

    Anh Dung Le🇫🇷

    In this thesis, we study the detailed partonic content of the quantum states of a quark-antiquark color dipole subject to high-energy evolution, which are represented by a set of dipoles generated by a stochastic binary branching process, in the scattering off a large nucleus, and produce predictions for diffractive dissociation in electron-ion collisions, based on the dipole picture of QCD. Our main results are as follows. First, the scattering events of a color dipole, when parameters are set in such a way that the total cross section is small, are triggered by rare partonic fluctuations, which look different as seen from different reference frames. It turns out that the freedom to select a frame allows to deduce an asymptotic expression for the rapidity distribution of the first branching of the slowest parent dipole of the set of those which scatter. In another aspect, such study implies the importance of the characterization of particle distribution in the frontier region in the states generated by the QCD dipole branching, and more generally, by any one-dimensional branching random walk model. To this aim, we develop a Monte Carlo algorithm to generate the frontier region of a branching random walk. Furthermore, we are able to calculate the diffractive cross section demanding a minimal rapidity gap $Y_0$ and the distribution of rapidity gaps $Y_{gap}$ in the diffractive dissociation of a small dipole off a large nucleus, in a well-defined parametric region. They are the asymptotic solutions to the so-called Kovchegov-Levin equation, which describes the diffractive dissociation at high energy. Finally, we present predictions for the rapidity gap distributionin realistic kinematics of future electron-ion machines, based on the numerical solutions of the original Kovchegov-Levin equation and of its next-to-leading extension taking into account the running of the strong coupling.

    hep-phcond-mat.stat-mech3 citations
11. 11*

    A description of charmonia decays $J/\psi \to B\bar{B}$ within the QCD factorisation framework

    Nikolay Kivel🇩🇪

    Decays $J/\psi \to B\bar{B}$ into octet baryon-antibaryons pairs are studied within the QCD factorisation framework. The next-to-leading power correction to the leading-order decay amplitude is calculated for the first time. The phenomenological analysis also includes the interference with the electromagnetic decay $J/\psi \to {\gamma }^{\ast }\to B\bar{B}$. The branching fractions and the angular coefficients ${\alpha }_B$ are described with an accuracy of about $20\%$. The obtained results allow us to conclude that the calculated amplitudes provide a dominant contribution and therefore QCD factorisation provides a suitable basis for understanding of these decays.

    hep-phEPJA(2022)·6 citations
12. 12*

    Spin-Dependent Scattering of Scalar and Vector Dark Matter and an Electron

    Ke-Yun Wu🇨🇳 · Zhao-Hua Xiong🇨🇳

    The property of dark matter is unknown so far. However, a model-independent classification of dark matter candidates can be achieved by using various symmetries, as done in the Standard Model. Fermionic dark matter has been researched extremely, one favored candidate is the neutralino in the Minimal Supersymmetric Standard Model, which are required by fermion-boson symmetry and preservation of R-parity. Bosonic dark matter has not been studied sufficiently, especially the scenario of dark matter with mass of sub-GeV. In this paper, we consider the effect of spin-dependent (SD) on scalar and vector dark matter, which are mediated by pseudo-scalar and axial-vector, and evaluate effect on the dark matter-electron scattering cross section. We list all the interaction and form factor of dark matter-electron SD scattering, and use XENON10/100/1T experiment data to derive the exclude limit of SD cross section. We find that the SD scattering of scalar and vector dark matter can be three orders of magnitude stronger than spin-independent (SI) scattering, due to the $p$-wave scattering.

    hep-phhep-exSymmetry(2022)·8 citations
13. 13*

    The influence of the scalar unparticle on the Z-production at high energy $e^{-}{e}^{+}$ scattering process

    Bui Thi Ha Giang🇻🇳

    An attempt is made to present the contribution of the scalar unparticle on the Z-production cross-section at International Linear Colliders (ILC) with polarized initial beams in the Randall-Sundrum model. The cross-sections depend strongly on the polarization of $e^{-}$, $e^{+}$ initial beams, the center of mass energy $\sqrt{s}$, the scaling dimension $d_U$ of the unparticle operator ${\mathcal{O}}_U$ and the energy scale ${\Lambda }_U$. The results indicate that with the effect of the scalar propagators in the s-channel, including radion, Higgs and scalar unparticle, the cross-section for the ZZ production is enhanced and larger than that in the Standard model under the same conditions.

    hep-ph0 citations
14. 14*

    Higgs boson decays into a pair of heavy vector quarkonia

    Dao-Neng Gao🇨🇳 · Xi Gong🇨🇳

    Rare Higgs decays into a pair of heavy vector quarkonia, $h\to VV$ ($V=J/\Psi$, ${\rm Y}$ etc.), have been investigated in the standard model. Different from the past literature in which these decays are thought to be only dominated by the longitudinally polarized final states, we also include the transitions, which proceed through $h\to {\gamma }^{\ast }{\gamma }^{\ast }$/$h\to V{\gamma }^{\ast }$, followed by ${\gamma }^{\ast }\to V$. The final vector quarkonia via these ways are dominantly transversely polarized. Our calculation however shows that these transitions could lead to significant contributions to the decay rate, especially for the charmonium final states. The total branching ratios of these processes are predicted to be around $10^{-10}$, far below the current experimental upper bounds. Hopefully, experimental studies of these very rare decays in future high-precision experimental facilities might be interesting both to test the standard model and to look for new physics scenarios.

    hep-phhep-exPLB(2022)·20 citations
15. 15*

    Spelling Out Leptonic CP Violation in the Language of Invariant Theory

    Bingrong Yu🇨🇳 · Shun Zhou🇨🇳

    In terms of flavor invariants, we establish the intimate connection between leptonic CP violation in the canonical seesaw model for neutrino masses and that in the seesaw effective field theory (SEFT). For the first time, we calculate the Hilbert series and explicitly construct the primary flavor invariants in the SEFT by considering both the dimension-five Weinberg operator ${\mathcal{O}}_5^{\alpha \beta }=\overline{{\ell }_{\alpha \mathrm{L}}^{}}\tilde{H}{\tilde{H}}^{\mathrm{T}}{\ell }_{\beta \mathrm{L}}^{\mathrm{C}}$ and the dimension-six operator ${\mathcal{O}}_6^{\alpha \beta }=\overline{{\ell }_{\alpha \mathrm{L}}^{}}\tilde{H}\mathrm{i}/\partial {\tilde{H}}^{†}{\ell }_{\beta \mathrm{L}}^{}$ at the tree-level matching. The inclusion of only the Wilson coefficients $C_5^{\alpha \beta }$ and $C_6^{\alpha \beta }$ already enables the SEFT to incorporate all physical information about the full seesaw model. Moreover, the minimal sufficient and necessary conditions for CP conservation both in the SEFT and in the full theory are clarified, and the matching between the flavor invariants in both theories is accomplished. Through the matching of flavor invariants, the CP asymmetries necessary for successful leptogenesis are directly linked to those in neutrino-neutrino and neutrino-antineutrino oscillations at low energies. Surprisingly, it is revealed that the precise measurements of $C_5^{\alpha \beta }$ and $C_6^{\alpha \beta }$ in low-energy experiments are powerful enough to probe the full seesaw model, including CP violation for cosmological matter-antimatter asymmetry.

    hep-phPRD(2022)·18 citations
16. 16*

    Meson masses and decay constants in holographic QCD consistent with ChPT and HQET

    Valery E. Lyubovitskij🇩🇪 · Ivan Schmidt🇨🇱

    We focus on the chiral and heavy quark mass expansion of mesons masses and decay constants. We propose a light-front QCD formalism for the evaluation of these quantities, consistent with chiral perturbation theory and heavy quark effective theory.

    hep-phPRD(2022)·12 citations
17. 17*

    Revealing the Cosmic History with Gravitational Waves

    Andreas Ringwald🇩🇪 · Carlos Tamarit🇩🇪

    The characteristics of the cosmic microwave background provide circumstantial evidence that the hot radiation-dominated epoch in the early universe was preceded by a period of inflationary expansion. Here, we show how a measurement of the stochastic gravitational wave background can reveal the cosmic history and the physical conditions during inflation, subsequent pre- and re-heating, and the beginning of the hot big bang era. This is exemplified with a particularly well-motivated and predictive minimal extension of the Standard Model which is known to provide a complete model for particle physics -- up to the Planck scale, and for cosmology -- back to inflation.

    hep-phastro-ph.COgr-qcPRD(2022)·57 citations
18. 18*

    Radiative Plateau Inflation with Conformal Invariance: Dynamical Generation of Electroweak and Seesaw Scales

    Anish Ghoshal🇵🇱 · Nobuchika Okada🇺🇸 · Arnab Paul🇮🇳

    We investigate a scale-invariant $B-L$ scenario where the Standard Model (SM) is supplemented with a dark scalar $\varphi$ which has gauge \& Yukawa interactions, with the couplings $g_{BL}$ and $y$, respectively, leading to radiative plateau inflation at scale $\varphi =M$ in the ultraviolet (UV), while dynamically generating the Electroweak and Seesaw scales \textitá lá Coleman-Weinberg in the infrared (IR). This is particularly achieved by implementing threshold corrections at an energy scale ${\mu }_T$ arising due to the presence of vector-like fermions. We show that implementing the inflationary observables makes the couplings solely dependent on the plateau scale $M$, leaving us with only two independent parameters $M$ and ${\mu }_T$. Within the theoretically consistent parameter space defined by $m_{Z_{BL}}>850\mathrm{GeV}$, from the assumption of independent evolution of the dark sector couplings from the SM couplings and $M<5.67M_P$ required for the realisation of inflationary \textit{plateau-like} behaviour of the potential around $\varphi =M$, where $M_P=2.4\times 10^{18}$ GeV is the reduced Planck mass, we identify the parameter space that is excluded by the current LHC results from the search for the heavy $Z_{BL}$ boson. For typical benchmark points in the viable parameter regions, we estimate the reheating temperature to be $\mathcal{O}(TeV)$ thus consistent with the standard Big Bang Nucleosynthesis (BBN) constraints. For typical benchmark points ($M=5.67,1,0.1M_P$) we predict the scales of inflation to be ${\mathcal{H}}_{inf}=2.79\times 10^{12}$ GeV, $1.53\times 10^{10}$ GeV and $1.53\times 10^7$ GeV, respectively.

    hep-phastro-ph.COPRD(2022)·12 citations
19. 19*

    Gravitational Waves from Incomplete Inflationary Phase Transitions

    Joel Barir🇮🇱 · Michael Geller🇮🇱 · Chen Sun🇮🇱 · Tomer Volansky🇮🇱

    We study the observable implications of an incomplete first order phase transition during inflation. In such a phase transition, the nucleated bubbles do not percolate and instead are continuously produced until the onset of reheating. The process creates an inhomogeneity with a distinct power spectrum that depends on both the physics of the phase transition and the inflationary dynamics. Upon horizon re-entry, this spectrum generates gravitational waves through non-linear effects. This stochastic gravitational wave background is predicted to have unique signatures that may be detectable by future experiments spanning a wide frequency range. The discovery of such a gravitational wave signal would shed a light on the detailed dynamics of inflation.

    hep-phastro-ph.COPRD(2023)·20 citations
20. 20*

    Isotope dependence of muon-to-electron conversion

    Julian Heeck🇺🇸 · Robert Szafron🇺🇸 · Yuichi Uesaka🇯🇵

    The lepton-flavor-violating conversion of a muon into an electron in the field of a nucleus is one of the most sensitive probes of physics beyond the Standard Model and the experiments Mu2e, COMET, and DeeMe will explore uncharted terrain in the near future. An observation of this ${\mu }^{-}\to e^{-}$ conversion process opens up the possibility to distinguish the underlying operator or new-physics model by exploiting the target-nucleus dependence of the conversion rate. To facilitate the choice of optimal targets we provide ${\mu }^{-}\to e^{-}$ conversion rates for all stable isotopes and estimate nuclear-structure uncertainties. Our results enable studies of mixed or enriched target materials that are particularly promising for distinguishing scenarios in which the muon converts either on protons or neutrons.

    hep-phhep-exNPB(2022)·25 citations
21. 21*

    MuMuPy: A Dimuonium-Matter Interaction Calculator

    Artem Uskov🇷🇺 · Abdaljalel Alizzi🇷🇺 · Z.K. Silagadze🇷🇺

    In this article, we present MuMuPy, a computational library and cloud-based tool for calculating cross sections for the interaction of dimuonium (true muonium) with matter. MuMuPy calculates corresponding form factors and allows one to find the probabilities of dimuonium transitions in the electric field of the nucleus. MuMuPy was developed in the context of the $\mu \mu$-tron facility, the project of a low-energy electron-positron collider for production and experimental study of dimuonium, proposed in our home institute, Budker Institute of Nuclear Physics. The reliability of MuMuPy was verified by three independent methods, one of which was developed by the authors earlier.

    hep-phphysics.comp-phComput.Phys.Commun.(2022)·1 citation
22. 22*

    Magnetising the $\mathcal{N}=4$ Super Yang-Mills plasma

    Alfonso Ballon-Bayona🇧🇷 · Jonathan P. Shock🇿🇦 · Dimitrios Zoakos🇬🇷

    We investigate the thermodynamics of the anisotropic magnetic $\mathrm{Ad}{\mathrm{S}}_5$ black brane solution found by D'Hoker and Kraus arXiv:0908.3875. This solution is the gravity dual of a strongly coupled $\mathcal{N}=4$ Super Yang-Mills plasma in ${\mathbb{R}}^{3,1}$, with temperature $T$, in the presence of a magnetic field $\mathcal{B}$. Following the procedure of holographic renormalisation we calculate the Gibbs free energy and the holographic stress tensor of the conformal plasma. We evaluate several thermodynamic quantities including the magnetisation, the anisotropic pressures and the speeds of sound. Our results are consistent with an RG flow from a perturbed $\mathrm{Ad}{\mathrm{S}}_5$ black brane at small $\mathcal{B}/T^2$ to a $\mathbf{BTZ}\times {\mathbb{R}}^2$ black brane at large $\mathcal{B}/T^2$. We also perform a phenomenological analysis where we compare the thermodynamics of a magnetised conformal plasma against the lattice QCD results for the thermodynamics of the magnetised quark-gluon plasma.

    ↳ hep-thhep-lathep-phJHEP(2022)·12 citations
23. 23*

    Transport coefficients of the quark-gluon plasma at the critical point and across the first-order line

    Joaquin Grefa🇺🇸 · Mauricio Hippert🇺🇸 · Jorge Noronha🇺🇸 · Jacquelyn Noronha-Hostler🇺🇸 · Israel Portillo🇺🇸 · Claudia Ratti🇺🇸 · Romulo Rougemont🇺🇸

    A bottom-up Einstein-Maxwell-Dilaton holographic model is used to compute, for the first time, the behavior of several transport coefficients of the hot and baryon-rich strongly coupled quark-gluon plasma at the critical point and also across the first-order phase transition line in the phase diagram. The observables under study are of the shear and bulk viscosities, baryon diffusion, thermal conductivity, the jet quenching parameter $\hat{q}$, as well as the heavy-quark drag force and Langevin diffusion coefficients. These calculations provide a phenomenologically promising estimate for these coefficients, given that our model quantitatively reproduces lattice QCD thermodynamics results, both at zero and finite baryon density, besides naturally incorporating the nearly-perfect fluidity of the quark-gluon plasma. We find that the diffusion of baryon charge, and also the shear and bulk viscosities, are suppressed with increasing baryon density, indicating that the medium becomes even closer to perfect fluidity at large densities. On the other hand, the jet quenching parameter and the heavy-quark momentum diffusion are enhanced with increasing density. The observables display a discontinuity gap when crossing the first-order phase transition line, while developing an infinite slope at the critical point. The transition temperatures associated with different transport coefficients differ in the crossover region but are found to converge at the critical point.

    ↳ nucl-thhep-phnucl-exPRD(2022)·66 citations
24. 24*

    Do Atoms Age?

    Mark G. Raizen🇺🇸 · David E. Kaplan🇺🇸 · Surjeet Rajendran🇺🇸

    Time evolution generically entangles a quantum state with environmental degrees of freedom. The resulting increase in entropy changes the properties of that quantum system leading to "aging". It is interesting to ask if this familiar property also applies to simple, single particle quantum systems such as the decay of a radioactive particle. We propose a test of such aging in an ion clock setup where we probe for temporal changes to the energies of the electronic state of an ion containing a radioactive nucleus. Such effects are absent in standard quantum mechanics and this test is thus a potent null test for violations of quantum mechanics. As a proof of principle, we show that these effects exist in causal non-linear modifications of quantum mechanics.

    ↳ quant-phhep-phhep-thPLB(2022)·6 citations
25. 25*

    Particle-based Fast Jet Simulation at the LHC with Variational Autoencoders

    Mary Touranakou🇨🇭 · Nadezda Chernyavskaya🇨🇭 · Javier Duarte🇺🇸 · Dimitrios Gunopulos🇬🇷 · Raghav Kansal🇺🇸 · Breno Orzari🇧🇷 · Maurizio Pierini🇨🇭 · Thiago Tomei🇧🇷 · Jean-Roch Vlimant🇺🇸

    We study how to use Deep Variational Autoencoders for a fast simulation of jets of particles at the LHC. We represent jets as a list of constituents, characterized by their momenta. Starting from a simulation of the jet before detector effects, we train a Deep Variational Autoencoder to return the corresponding list of constituents after detection. Doing so, we bypass both the time-consuming detector simulation and the collision reconstruction steps of a traditional processing chain, speeding up significantly the events generation workflow. Through model optimization and hyperparameter tuning, we achieve state-of-the-art precision on the jet four-momentum, while providing an accurate description of the constituents momenta, and an inference time comparable to that of a rule-based fast simulation.

    ↳ physics.comp-phcs.LGhep-exhep-phMach.Learn.Sci.Tech.(2022)·25 citations
26. 26*

    Impact of hypermagnetic fields on relic gravitational waves, neutrino oscillations and baryon asymmetry

    Maxim Dvornikov (IZMIRAN)🇷🇺

    We study the evolution of random hypermagnetic fields (HMFs) in the symmetric phase of the early universe before the electroweak phase transition. The behavior of HMFs is driven by the analog of the chiral magnetic effect accounting for the asymmetries of leptons and Higgs bosons. These asymmetries are also dynamical variables of the model and evolve together with HMFs. Moreover, we account for the contribution of the hyper-MHD turbulence in the effective diffusion coefficient and the $\alpha$-dynamo parameter. The realistic spectrum of seed HMFs consists of two branches: Batchelor and Kolmogorov ones. The impact of HMFs on the production of relic gravitational waves (GWs) and the baryon asymmetry of the universe (BAU), as well as flavor oscillations of supernova neutrinos in the stochastic GWs generated, are considered. We establish the constraint on the strength of the seed HMF comparing the spectral density of produced GWs with the observations of the LIGO-Virgo-KAGRA collaborations. The stronger upper bound on the seed HMF is obtained from the condition of not exceeding the observed value of BAU.

    ↳ astro-ph.COhep-phInt.J.Mod.Phys.D(2023)·6 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.