Fri·Jan 21, 2022Friday·January 21, 2022

1. 01*

   Parton distributions of light quarks and antiquarks in the proton

   Lei Chang🇨🇳 · Fei Gao🇨🇳 · Craig D. Roberts🇨🇳

   An algebraic Ansatz for the proton's Poincaré-covariant wave function, which includes both scalar and pseudovector diquark correlations, is used to calculate proton valence, sea, and glue distribution functions (DFs). Regarding contemporary data, a material pseudovector diquark component in the proton is necessary for an explanation of the neutron-proton structure function ratio; and a modest Pauli blocking effect in the gluon splitting function is sufficient to explain the proton's light-quark antimatter asymmetry. In comparison with pion DFs, the light-front momentum fractions carried by all identifiable parton classes are the same; on the other hand, the higher moments are different. Understanding these features may provide insights that explain distinctions between Nambu-Goldstone bosons and seemingly less complex hadrons.

   hep-phhep-exhep-latnucl-ex+1PLB(2022)·38 citations
2. 02*

   Second order chiral phase transition in three flavor quantum chromodynamics?

   G. Fejos🇭🇺

   We calculate the renormalization group flows of all perturbatively renormalizable interactions in the three-dimensional Ginzburg-Landau potential for the chiral phase transition of three-flavor quantum chromodynamics. On the contrary to the common belief we find a fixed point in the system that is able to describe a second-order phase transition in the infrared. This shows that long-standing assumptions on the transition order might be false. If the transition is indeed of second-order, our results may hint that the axial $U(1)$ symmetry restores at the transition temperature.

   hep-phPRD(2022)·37 citations
3. 03*

   Event-by-event investigation of the two-particle source function in heavy-ion collisions with EPOS

   Dániel Kincses🇭🇺 · Maria Stefaniak🇵🇱 · Máté Csanád🇭🇺

   Exploring the shape of the pair-source function for particles such as pions or kaons has been an important goal of heavy-ion physics, and substantial effort has been made in order to understand the underlying physics behind the experimental observations of non-Gaussian behavior. In experiments, since no direct measurement of the source function is possible, quantum-statistical momentum correlations are utilized to gain information about the space-time geometry of the particle emitting source. Event generators, such as EPOS, however, provide direct access to the freeze-out coordinates of final state particles, and thus the source function can be constructed and investigated. The EPOS model is a sophisticated hybrid model where the initial stage evolution of the system is governed by Parton-Based Gribov-Regge theory, and subsequently a hydrodynamic evolution is utilized, followed by hadronization and hadron dynamics. EPOS has already proven to be successful in describing several different experimental observations for systems characterized by baryon chemical potential close to zero, but so far the source shape has not been explored in detail. In this paper we discuss an event-by-event analysis of the two-particle source function in $\sqrt{s_{NN}}$ = 200 GeV Au+Au collisions generated by the EPOS model. We find that when utilizing all stages of the model, Lévy-shaped distributions (unlike Gaussian distributions) provide a good description of the source shape in the individual events. Hence it is clear that it is not the event averaging that creates the non-Gaussian features in the pair distributions. Based on this observation, we determine Lévy-parameters of the source as a function of event centrality and particle momentum.

   hep-phnucl-thEntropy(2022)·24 citations
4. 04*

   Generation of vortex particles via generalized measurements

   D. V. Karlovets🇷🇺 · S. S. Baturin🇷🇺 · G. Geloni🇩🇪 · G. K. Sizykh🇷🇺 · V. G. Serbo🇷🇺

   The hard X-ray twisted photons and relativistic massive particles with orbital angular momentum -- vortex electrons, muons, protons, etc. -- have many potential applications in high-energy and nuclear physics. However, such states can be obtained so far mainly via diffraction techniques, not applicable for relativistic energies. Here we show that the vortex states of different particles, including hadrons, ions, and nuclei, can be generated in a large class of processes with two final particles simply by altering a postselection protocol. Thanks to entanglement and to the uncertainty relations, an evolved state of a final particle becomes twisted if the momentum azimuthal angle of the other particle is measured with a large uncertainty. We give several examples, including Cherenkov and undulator radiation, particle collisions with intense laser beams, $e\mu \to e\mu ,ep\to ep$. This technique can be adapted for ultrarelativistic lepton and hadron beams of linear colliders, and it can also facilitate the development of sources of X-ray and $\gamma$-range twisted photons at storage rings and free-electron lasers.

   hep-phphysics.acc-phquant-phEPJC(2022)·23 citations
5. 05*

   Influence of cross-sectional uncertainty on sensitivity studies of DUNE and T2HK experiments

   Ritu Devi🇮🇳 · Jaydip Singh🇮🇳 · Baba Potukuchi🇮🇳

   The ultimate objectives of ongoing and upcoming neutrino experiments are the precise measurement of neutrino mixing parameters and the confirmation of mass hierarchy. The systematic inaccuracy in the cross-section models introduces inaccuracy in the neutrino mixing parameters estimation. It is important to secure a large decrease of uncertainties, particularly those relating to cross-section, neutrino-nucleus interactions, and neutrino-energy reconstruction, in order to achieve these ambitious goals. In this research article, we use three alternative neutrino event generators, GENIE, NuWro, and GiBUU, to analyze sensitivity studies of T2HK, DUNE, and combined sensitivity of DUNE, and T2HK for mass hierarchy, CP violation, and octant degeneracy caused by cross-section uncertainties. The cross-section models of these generators are separate and independent.

   hep-phInt.J.Theor.Phys.(2022)·2 citations
6. 06*

   Multivariable evolution in final state parton shower algorithms

   Zoltan Nagy🇩🇪 · Davison E. Soper🇺🇸

   One can use more than one scale variable to specify the family of surfaces in the space of parton splitting parameters that define the evolution of a parton shower. Considering $e^{+}{e}^{-}$ annihilation, we use two variables, with shower evolution following a special path in this two dimensional space. In addition, we treat in a special way the part of the splitting function that has a soft emission singularity but no collinear singularity. This leads to certain advantages compared to the usual shower formulation with only one scale variable.

   hep-phPRD(2022)·5 citations
7. 07*

   Electromagnetic and gravitational form factors of $\Delta$ resonance in a covariant quark-diquark approach

   Dongyan Fu🇨🇳 · Bao-Dong Sun🇨🇳 · Yubing Dong🇨🇳

   In this work, the electromagnetic and gravitational form factors of a spin-$3/2$ particle, $\Delta$ resonance, are simultaneously calculated with the help of a relativistic covariant quark-diquark approach. The two kinds of form factors are separately extracted from the matrix elements of the electromagnetic current and of the energy-momentum tensor of the system. Our numerical results show that the approach can well reproduce the electromagnetic monopole, dipole, quadrupole, and octupole form factors comparing to the Lattice calculations. Our obtained electromagnetic moments are also comparable with some other approaches. Moreover, the obtained gravitational form factors, which give the mechanical properties of the system like the mass and spin distributions, are also displayed for the $\Delta$ isobar. In addition, some discussions of the sign and the interpretation of the D-term are particularly given.

   hep-phPRD(2022)·30 citations
8. 08*

   Fluidity of the system produced in relativistic pp and heavy-ion collisions: Hadron resonance gas model approach

   Ronald Scaria🇮🇳 · Dushmanta Sahu🇮🇳 · Captain R. Singh🇮🇳 · Raghunath Sahoo🇮🇳 · Jan-e Alam🇮🇳

   We have estimated the dimensionless parameters such as Reynolds number ($Re$), Knudsen number ($Kn$) and Mach number ($Ma$) for a multi-hadron system by using the excluded volume hadron resonance gas (EVHRG) model along with Hagedorn mass spectrum to include higher resonances in the system. The size dependence of these parameters indicate that the system formed in proton+proton collisions may achieve thermal equilibrium making it unsuitable as a benchmark to analyze the properties of the system produced in heavy ion collisions at similar energies. While the magnitude of $Kn$ can be used to study the degree of thermalization and applicability of inviscid hydrodynamics, the variations of $Re$ and $Ma$ with temperature ($T$) and baryonic chemical potential (${\mu }_B$) assist to understand the change in the nature of the flow in the system. Indeed the nature of flow changes from laminar to turbulent as $Re$ increases and the system is characterized as incompressible for low $Ma(<<1)$ and compressible for larger $Ma$. $Ma$ can also be used to understand whether the flow is subsonic or supersonic.

   hep-phhep-exnucl-exnucl-thEPJA(2023)·9 citations
9. 09*

   Quasiclassical representation of the Volkov propagator and the tadpole diagram in a plane wave

   A. Di Piazza🇩🇪 · F. P. Fronimos🇩🇪

   The solution of the Dirac equation in the presence of an arbitrary plane wave, corresponding to the so-called Volkov states, has provided an enormous insight in strong-field QED. In [Phys. Rev. A \textbf{103}, 076011 (2021)] a new "fully quasiclassical" representation of the Volkov states has been found, which is equivalent to the one known in the literature but which more transparently shows the quasiclassical nature of the quantum dynamics of an electron in a plane-wave field. Here, we derive the corresponding expression of the propagator by constructing it using the fully quasiclassical form of the Volkov states. The found expression allows one, together with the fully quasiclassical expression of the Volkov states, to compute probabilities in strong-field QED in an intense plane wave by manipulating only 2-by-2 rather than 4-by-4 Dirac matrices as in the usual approach. Moreover, apart from the exponential functions featuring the classical action of an electron in a plane wave, the fully quasiclassical Volkov propagator depends only on the electron kinetic four-momentum in the plane wave, which is a gauge-invariant quantity. Finally, we also compute the one-loop tadpole diagram in a plane wave starting from the Volkov propagator and we find that after renormalization it identically vanishes.

   hep-phPRD(2022)·5 citations
10. 10*

    Axions in Baryon Chiral Perturbation Theory

    Thomas Vonk🇩🇪

    I give an overview of recent developments in the study of the coupling of the QCD axion to nucleons and other octet baryons. I demonstrate how axions can be included into heavy baryon chiral perturbation theory, and present recent numerical results for the several axion-baryon couplings in SU(2) and SU(3) chiral perturbation theory for the Kim--Shifman--Vainstein--Zakharov (KSVZ) and the Dine--Fischler--Srednicki--Zhitnitsky (DFSZ) axion model.

    hep-phnucl-thPoS(2022)·0 citations
11. 11*

    Decay of the charged Higgs boson and the top quark in two-Higgs-doublet model at NNLO in QCD

    Xiao-Min Shen🇨🇳 · YaLu Hu🇨🇳 · ChuanLe Sun🇨🇳 · Jun Gao🇨🇳

    We present numerical calculations of the partial width of the charged Higgs boson decay into a top quark, $H^{-}\to \bar{t}+b+X$, and the partial width of the top quark decay into a light charged Higgs boson $t\to H^{+}+b+X$ at next-to-next-to-leading order (NNLO) in QCD, based on a factorization formula of the jet mass. The NNLO corrections significantly reduce the renormalization scale dependence of the partial decay width in both cases. We show relative size of the NNLO corrections for different charged Higgs boson masses and for different renormalization scales. The NNLO corrections are about 16% (1%) of the leading order widths for the charged Higgs boson mass of 200GeV (2000GeV), while it is quite small for the top quark decay. Our analyses are independent of the detailed structure of the Yukawa couplings, and can be applied to various new physics models, as demonstrated by the decay branching ratio in different types of the two-Higgs-doublet models.

    hep-phhep-exJHEP(2022)·4 citations
12. 12*

    Unified Explanation of the Anomalies in Semi-Leptonic $B$ decays and the $W$ Mass

    Marcel Algueró🇪🇸 · Andreas Crivellin🇨🇭 · Claudio Andrea Manzari🇨🇭 · Joaquim Matias🇪🇸

    The discrepancies between the measurements of rare (semi-)leptonic $B$ decays and the corresponding Standard Model predictions point convincingly towards the existence of new physics for which a heavy neutral gauge boson ($Z^{\prime }$) is a prime candidate. However, the effect of the mixing of the $Z^{\prime }$ with the SM $Z$, even though it cannot be avoided by any symmetry, is usually assumed to be small and thus neglected in phenomenological analyses. In this letter we point out that a mixing of the naturally expected size leads to lepton flavour universal contributions, providing a very good fit to $B$ data. Furthermore, the global electroweak fit is affected by $Z-Z^{\prime }$ mixing where the tension in the $W$ mass, recently confirmed and strengthened by the CDF measurement, prefers a non-zero value of it. We find that a $Z^{\prime }$ boson with a mass between $\approx 1-5\mathrm{TeV}$ can provide a unified explanations of the $B$ anomalies and the $W$ mass. This strongly suggests that the breaking of the new gauge symmetry giving raise to the $Z^{\prime }$ boson is linked to electroweak symmetry breaking with intriguing consequences for model building.

    hep-phhep-exnucl-exnucl-thPRD(2022)·36 citations
13. 13*

    Forward-backward multiplicity distribution with the Chou-Yang model for $pp$ collisions at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS experiment

    Z. Ong🇸🇬 · P. Agarwal🇸🇬 · H.W. Ang🇸🇬 · A.H. Chan🇸🇬 · C.H. Oh🇸🇬

    A Chou-Yang type multiplicity distribution comprising a total multiplicity component and a binomial asymmetry component is used to describe charged hadron multiplicity data at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS experiment at CERN. The data was obtained and processed from the CERN Open Data Portal. For the total multiplicity component, it was found that a convex sum of a Negative Binomial Distribution and a Furry-Yule Distribution is able to describe the shoulder-like structure characteristic of KNO scaling violation well. The mean cluster size produced from collisions was also found to increase with collision energy. A prediction is given for $pp$ collisions at $\sqrt{s}=$ 14 TeV.

    hep-phhep-exMod.Phys.Lett.A(2023)·1 citation
14. 14*

    Multifractal behaviour in multiparticle production in $pp$ collisions at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS experiment

    Z. Ong🇸🇬 · P. Agarwal🇸🇬 · H.W. Ang🇸🇬 · A.H. Chan🇸🇬 · C.H. Oh🇸🇬

    Multifractal analysis was performed on $pp$ collision data at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS experiment at CERN. The data was obtained and processed from the CERN Open Data Portal. Vertical analysis was used to compute the generalised dimensions $D_q$ and the multifractal spectra $f(\alpha )$ of the data, which reveals the level of complexity of its pseudorapidity distribution. It was found that the $f(\alpha )$ curves widen with increasing collision energy, signalling an increase in branching complexity.

    hep-phhep-ex1 citation
15. 15*

    An Efficient Lorentz Equivariant Graph Neural Network for Jet Tagging

    Shiqi Gong🇨🇳 · Qi Meng · Jue Zhang · Huilin Qu🇨🇭 · Congqiao Li🇨🇳 · Sitian Qian🇨🇳 · Weitao Du🇨🇳 · Zhi-Ming Ma🇨🇳 · Tie-Yan Liu

    Deep learning methods have been increasingly adopted to study jets in particle physics. Since symmetry-preserving behavior has been shown to be an important factor for improving the performance of deep learning in many applications, Lorentz group equivariance - a fundamental spacetime symmetry for elementary particles - has recently been incorporated into a deep learning model for jet tagging. However, the design is computationally costly due to the analytic construction of high-order tensors. In this article, we introduce LorentzNet, a new symmetry-preserving deep learning model for jet tagging. The message passing of LorentzNet relies on an efficient Minkowski dot product attention. Experiments on two representative jet tagging benchmarks show that LorentzNet achieves the best tagging performance and improves significantly over existing state-of-the-art algorithms. The preservation of Lorentz symmetry also greatly improves the efficiency and generalization power of the model, allowing LorentzNet to reach highly competitive performance when trained on only a few thousand jets. Code and models are available at \url{https://github.com/sdogsq/LorentzNet-release}.

    hep-phhep-exJHEP(2022)·161 citations
16. 16*

    Bubble wall dynamics at the electroweak phase transition

    Stefania De Curtis🇮🇹 · Luigi Delle Rose🇪🇸 · Andrea Guiggiani🇮🇹 · Ángel Gil Muyor🇪🇸 · Giuliano Panico🇮🇹

    First order phase transitions could play a major role in the early universe, providing important phenomenological consequences, such as the production of gravitational waves and the generation of baryon asymmetry. An important aspect that determines the properties of the phase transition is the dynamics of the true-vacuum bubbles, which is controlled by the density perturbations in the hot plasma. We study this aspect presenting, for the first time, the full solution of the linearized Boltzmann equation for the top quark species coupled to the Higgs field during a first-order electroweak phase transition. Our approach, differently from the traditional one based on the fluid approximation, does not rely on any ansatz and can fully capture the density perturbations in the plasma. We find that our results significantly differ from the ones obtained in the fluid approximation (including its extensions and modifications), both at the qualitative and quantitative level. In particular sizable differences are found for the friction acting on the bubble wall.

    hep-phastro-ph.COhep-thJHEP(2022)·97 citations
17. 17*

    A combined analysis of the $Z_c(3900)$ and the $Z_{cs}(3985)$ exotic states

    Meng-Lin Du🇪🇸 · Miguel Albaladejo🇪🇸 · Feng-Kun Guo🇨🇳 · Juan Nieves🇪🇸

    We have performed a combined analysis of the BESIII data for both the $Z_c(3900)$ and $Z_{cs}(3985)$ structures, assuming that the latter is an SU(3) flavor partner of the former one. We have improved on the previous analysis of Albaladejo $et$ $al.$ [Phys. Lett. B 755, 337 (2016)] by computing the amplitude for the $D_1\bar{D}{D}^{\ast }$ triangle diagram considering both $D$ and $S$-wave $D_1{D}^{\ast }\pi$ couplings. We have also investigated effects from SU(3) light-flavor violations, which are found to be moderate and of the order of 20%. The successful reproduction of the BESIII spectra, in both the hidden-charm and hidden-charm strange sectors, strongly supports that the $Z_{cs}(3985)$ and $Z_c(3900)$ are SU(3) flavor partners placed in the same octet multiplet. The best results are obtained when an energy-dependent term in the diagonal $D^{(\ast )}{\bar{D}}_{(s)}^{(\ast )}$ interaction is included, leading to resonances (poles above the thresholds) to describe these exotic states. We have also made predictions for the isovector $Z_c^{\ast }$ and isodoublet $Z_{cs}^{\ast }$, $D^{\ast }{\bar{D}}^{\ast }$ and $D^{\ast }{\bar{D}}_s^{\ast }$ molecules, with $J^{PC}=1^{+-}$ and $J^P=1^{+}$, respectively. These states would be heavy-quark spin symmetry partners of the $Z_c$ and $Z_{cs}$. Besides the determination of the masses and widths of the $Z_c(3900)$ and $Z_{cs}(3985)$, we also predict those of the $Z_c^{\ast }$ and $Z_{cs}^{\ast }$ resonances.

    hep-phPRD(2022)·55 citations
18. 18*

    Quantum dual-path interferometry scheme for axion dark matter searches

    Qiaoli Yang🇨🇳 · Yu Gao🇨🇳 · Zhihui Peng🇨🇳

    Exploring the mysterious dark matter is a key quest in modern physics. Currently, detecting axions, a hypothetical particle proposed as a primary component of dark matter, remains a significant challenge due to their weakly interacting nature. Here we show at quantum level that in a cavity permeated by a magnetic field, the single axion-photon conversion rate is enhanced by the cavity quality factor and is quantitatively larger than the classical result by $\pi /2$. The axion cavity can be considered a quantum device emitting single photons with temporal separations. This differs from the classical picture and reveals a possibility for the axion cavity experiment to handle the signal sensitivity at the quantum level, e.g., a dual path quantum interferometry with cross-power and second-order correlation measurements. This scheme would greatly reduce the signal scanning time and improve the sensitivity of the axion-photon coupling, potentially leading to the direct observation of axions.

    hep-phastro-ph.COquant-phCommun.Phys.(2024)·10 citations
19. 19*

    Bottomonium spectroscopy using Coulomb plus linear (Cornell) potential

    Virendrasinh Kher🇮🇳 · Raghav Chaturvedi🇦🇪 · Nayneshkumar Devlani🇮🇳 · A. K. Rai🇮🇳

    The coulomb plus linear (Cornell) potential is used to investigate the mass spectrum of bottomonium. Gaussian wave function is used in position and momentum space to estimate values of potential and kinetic energies, respectively. Based on our calculations, we study newly observed ${\rm Y}(10860)$ as an admixture of $4^3{S}_1$ with $4^3{D}_1$, and ${\rm Y}(10753)$ as an admixture of $6^3{S}_1$ with $4^3{D}_1$ also, we try to assign $\mathbf{{\rm Y}}(11020)$ as a pure $4^3{D}_1$ bottomonium state. We also study the Regge trajectories in the $(J,M^2)$ and $(n_r,M^2)$ planes to help prove our association. We estimate the pseudoscalar and vector decay constants, the radiative (Electric and Magnetic Dipole) transition rates, and the annihilation decay width for bottomonium states.

    hep-phEur.Phys.J.Plus(2022)·38 citations
20. 20*

    A New Paradigm for Precision Top Physics: Weighing the Top with Energy Correlators

    Jack Holguin🇫🇷 · Ian Moult🇺🇸 · Aditya Pathak🇬🇧 · Massimiliano Procura🇦🇹

    Final states in collider experiments are characterized by correlation functions, $⟨E({\vec{n}}_1)\cdots E({\vec{n}}_k)⟩$, of the energy flow operator $E({\vec{n}}_i)$. We show that the top quark imprints itself as a peak in the three-point correlator at an angle $\zeta \sim m_t^2/p_T^2$, with $m_t$ the top quark mass and $p_T$ its transverse momentum, providing access to one of the most important parameters of the Standard Model in one of the simplest field theoretical observables. Our analysis provides the first step towards a new paradigm for a precise top mass determination that is, for the first time, highly insensitive to soft physics and underlying event contamination whilst remaining directly calculable from the Standard Model Lagrangian.

    hep-phhep-exhep-thPRD(2023)·83 citations
21. 21*

    Factorization connecting continuum and lattice TMDs

    Markus A. Ebert🇩🇪 · Stella T. Schindler🇺🇸 · Iain W. Stewart🇺🇸 · Yong Zhao🇺🇸

    Transverse-momentum-dependent parton distribution functions (TMDs) can be studied from first principles by a perturbative matching onto lattice-calculable quantities: so-called lattice TMDs, which are a class of equal-time correlators that includes quasi-TMDs and TMDs in the Lorentz-invariant approach. We introduce a general correlator that includes as special cases these two Lattice TMDs and continuum TMDs, like the Collins scheme. Then, to facilitate the derivation of a factorization relation between lattice and continuum TMDs, we construct a new scheme, the Large Rapidity (LR) scheme, intermediate between the Collins and quasi-TMDs. The LR and Collins schemes differ only by an order of limits, and can be matched onto one another by a multiplicative kernel. We show that this same matching also holds between quasi and Collins TMDs, which enables us to prove a factorization relation between these quantities to all orders in ${\alpha }_s$. Our results imply that there is no mixing between various quark flavors or gluons when matching Collins and quasi TMDs, making the lattice calculation of individual flavors and gluon TMDs easier than anticipated. We cross-check these results explicitly at one loop and discuss implications for other physical-to-lattice scheme factorizations.

    hep-phhep-latnucl-thJHEP(2022)·55 citations
22. 22*

    Modelling $W^{+}{W}^{-}$ production with rapidity gaps at the LHC

    S. Bailey🇬🇧 · L. A. Harland-Lang🇬🇧

    We present a new calculation of $W^{+}{W}^{-}$ production in the semi-exclusive channel, that is either with intact outgoing protons or rapidity gaps present in the final state, and with no colour flow between the colliding protons. This study provides the first complete prediction of the $W^{+}{W}^{-}$ semi-exclusive cross section, as well as the breakdown between elastic and proton dissociative channels. It combines the structure function calculation for a precise modelling of the region of low momentum transfers with a parton-level calculation in the region of high momentum transfers. The survival factor probability of no additional proton-proton interactions is fully accounted for, including its kinematic and process dependence. We analyse in detail the role that the pure photon-initiated ($\gamma \gamma \to W^{+}{W}^{-}$) subprocess plays, a comparison that is only viable by working in the electroweak axial gauge. In this way, we find that the dominance of this is not complete in the proton dissociative cases, although once $Z$-initiated production is included a significantly better matching to the complete calculation is achieved. A direct consequence of this is that the relative elastic, single and double dissociative fractions are in general different in comparison to the case of lepton pair production. We present a direct comparison to the recent ATLAS data on semi-exclusive $W^{+}{W}^{-}$ production, finding excellent agreement within uncertainties. Our calculation is provided in the publicly available SuperChic 4.1 Monte Carlo (MC) generator, and can be passed to a general purpose MC for showering and hadronization of the final state.

    hep-phhep-exPRD(2022)·15 citations
23. 23*

    Event-by-event jet anisotropy and hard-soft tomography of the quark-gluon plasma

    Yayun He🇨🇳 · Wei Chen🇨🇳 · Tan Luo🇪🇸 · Shanshan Cao🇨🇳 · Long-Gang Pang🇨🇳 · Xin-Nian Wang🇨🇳

    Suppression of jet spectra or jet quenching in high-energy heavy-ion collisions is caused by jet energy loss in the dense medium. The azimuthal anisotropy of jet energy loss in non-central heavy-ion collisions can lead to jet anisotropy which in turn can provide insight into the path-length dependence of jet quenching. This is investigated within the Linear Boltzmann Transport (LBT) model which simulates both elastic scattering and medium-induced gluon radiation based on perturbative QCD for jet shower and medium recoil partons as well as radiated gluons as they propagate through the quark-gluon plasma (QGP). The dynamical evolution of the QGP in each event of heavy-ion collisions is provided by the (3+1)D CLVisc hydrodynamic model with fully fluctuating initial conditions. This framework has been shown to describe the suppression of single inclusive jet spectra well. We calculate in this study the elliptic ($v_2^{\mathrm{jet}}$) and triangular ($v_3^{\mathrm{jet}}$) anisotropy coefficients of the single inclusive jet spectra in Pb+Pb collisions at the LHC energies. We investigate the colliding energy, centrality, jet transverse momentum dependence of the jet anisotropy, as well as their event-by-event correlation with the flow coefficients of the soft bulk hadrons. An approximate linear correlation between jet and bulk $v_2$ is found. Effect of the bulk $v_n$ fluctuation on $v_n^{\mathrm{jet}}$ is found negligible. The jet-induced medium excitation, which is influenced by radial flow, is shown to enhance $v_2^{\mathrm{jet}}$ and the enhancement increases with the jet cone size. The jet elliptic anisotropy $v_2^{\mathrm{jet}}$ is also found to be slightly enhanced by the shear viscosity of the bulk medium in comparison to the LBT results when jets propagate through an ideal hydrodynamic QGP medium.

    hep-phnucl-thPRC(2022)·35 citations
24. 24*

    Chiral anomaly in non-relativistic systems: Berry curvature and chiral kinetic theory

    Lan-Lan Gao🇨🇳 · Xu-Guang Huang🇨🇳

    Chiral anomaly and the novel quantum phenomena it induces have been widely studied for Dirac and Weyl fermions. In most typical cases, the Lorentz covariance is assumed and thus the linear dispersion relations are maintained. However, in realistic materials, such as Dirac and Weyl semimetals, the non-linear dispersion relations appear naturally. We develop a kinetic framework to study the chiral anomaly for Weyl fermions with non-linear dispersions by using the methods of Wigner function and semi-classical equations of motion. In this framework, the chiral anomaly is sourced by Berry monopoles in momentum space and could be enhanced or suppressed due to the windings around the Berry monopoles. Our results can help understand the chiral anomaly-induced transport phenomena in non-relativistic systems.

    ↳ cond-mat.mes-hallcond-mat.str-elhep-phnucl-th+1Chin.Phys.Lett.(2022)·9 citations
25. 25*

    New insight in the 2-flavor Schwinger model based on lattice simulations

    Jaime Fabián Nieto Castellanos🇲🇽 · Wolfgang Bietenholz🇲🇽 · Ivan Hip🇭🇷

    We consider the Schwinger model with two degenerate, light fermion flavors by means of lattice simulations. At finite temperature, we probe the viability of a bosonization method by Hosotani et al. Next we explore an analogue to the pion decay constant, which agrees for independent formulations based on the Gell-Mann--Oakes--Renner relation, the 2-dimensional Witten--Veneziano formula and the $\delta$-regime. Finally we confront several conjectures about the chiral condensate with lattice results.

    ↳ hep-lathep-phRev.Mex.Fis.Suppl.(2022)·3 citations
26. 26*

    Intermittency analysis of $pp$ collisions at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS experiment

    Z. Ong🇸🇬 · P. Agarwal🇸🇬 · H.W. Ang🇸🇬 · A.H. Chan🇸🇬 · C.H. Oh🇸🇬

    The method of horizontal scaled factorial moments as outlined by Bialas and Peschanski was used to conduct intermittency analysis for $pp$ collisions at $\sqrt{s}=$ 0.9, 7 and 8 TeV from the CMS experiment. The data was obtained and processed from the CERN Open Data Portal. It was found from 1D analysis that the intermittency strength decreases with increasing energy, indicating that the signature of the $\alpha$-model of random cascading that the former is based on seems to be weakening. Intermittency was stronger in 2D, but did not reveal any clear trend with increasing collision energy.

    ↳ hep-exhep-ph0 citations
27. 27*

    Strangeness $S=-3$ and $-4$ baryon-baryon interactions in chiral effective field theory

    J. Haidenbauer🇩🇪 · U.-G. Meißner🇩🇪

    Studies of the baryon-baryon interaction involving hyperons within chiral effective field theory, so far performed up to next-to-leading order (NLO) in the chiral expansion, have shown that for the strangeness $S=-1$ ($\Lambda N$, $\Sigma N$) and $S=-2$ ($\Lambda \Lambda$, $\Xi N$) sectors a consistent and satisfactory description of the available scattering data and experimental constraints can be achieved based on the assumption of broken SU(3) flavor symmetry. We explore the possible extension of this approach at the NLO level to strangeness $S=-3$ and $S=-4$ baryon-baryon systems where empirical information is rather scarce. Specifically we address the question how measurements of two-body correlation functions in heavy-ion collisions and/or in high-energetic proton-proton collisions can help to constrain the interaction in channels like $\Xi \Lambda$ or $\Xi \Xi$.

    ↳ nucl-thhep-phPoS(2024)·6 citations
28. 28*

    Superradiance in massive vector fields with spatially varying mass

    Zipeng Wang🇺🇸 · Thomas Helfer🇺🇸 · Katy Clough🇬🇧 · Emanuele Berti🇺🇸

    Superradiance is a process by which massive bosonic particles can extract energy from spinning black holes, leading to the build up of a "cloud" if the particle has a Compton wavelength comparable to the black hole's Schwarzschild radius. One interesting possibility is that superradiance may occur for photons in a diffuse plasma, where they gain a small effective mass. Studies of the spin-0 case have indicated that such a build up is suppressed by a spatially varying effective mass, supposed to mimic the photons' interaction with a physically realistic plasma density profile. We carry out relativistic simulations of a massive Proca field evolving on a Kerr background, with modifications to account for the spatially varying effective mass. This allows us to treat the spin-1 case directly relevant to photons, and to study the effect of thinner disk profiles in the plasma. We find similar qualitative results to the scalar case, and so support the conclusions of that work: either a constant asymptotic mass or a shell-like plasma structure is required for superradiant growth to occur. We study thin disks and find a leakage of the superradiant cloud that suppresses its growth, concluding that thick disks are more likely to support the instability.

    ↳ gr-qcastro-ph.HEhep-phPRD(2022)·28 citations
29. 29*

    The Weak Gravity Conjecture: A Review

    Daniel Harlow🇺🇸 · Ben Heidenreich🇺🇸 · Matthew Reece🇺🇸 · Tom Rudelius🇺🇸

    The Weak Gravity Conjecture holds that in a theory of quantum gravity, any gauge force must mediate interactions stronger than gravity for some particles. This statement has surprisingly deep and extensive connections to many different areas of physics and mathematics. Several variations on the basic conjecture have been proposed, including statements that are much stronger but are nonetheless satisfied by all known consistent quantum gravity theories. We review these related conjectures and the evidence for their validity in the string theory landscape. We also review a variety of arguments for these conjectures, which tend to fall into two categories: qualitative arguments which claim the conjecture is plausible based on general principles, and quantitative arguments for various special cases or analogues of the conjecture. We also outline the implications of these conjectures for particle physics, cosmology, general relativity, and mathematics. Finally, we highlight important directions for future research.

    ↳ hep-thhep-phRMP(2023)·287 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.