Thu·Oct 26, 2023Thursday·October 26, 2023

1. 01*

   The New Physics Case for Beam-Dump Experiments with Accelerated Muon Beams

   Cari Cesarotti🇺🇸 · Rikab Gambhir🇺🇸

   As the field examines a future muon collider as a possible successor to the LHC, we must consider how to fully utilize not only the high-energy particle collisions, but also any lower-energy staging facilities necessary in the R&D process. An economical and efficient possibility is to use the accelerated muon beam from either the full experiment or from cooling and acceleration tests in beam-dump experiments.Beam-dump experiments are complementary to the main collider as they achieve sensitivity to very small couplings with minimal instrumentation. We demonstrate the utility of muon beam-dump experiments for new physics searches at energies from 10 GeV to 5 TeV. We find that, even at low energies like those accessible at staging or demonstrator facilities, it is possible to probe new regions of parameter space for a variety of generic BSM models, including muonphilic, leptophilic, $L_{\mu }-L_{\tau }$, and dark photon scenarios. Such experiments could therefore provide opportunities for discovery of new physics well before the completion of the full multi-TeV collider.

   hep-phJHEP(2024)·32 citations
2. 02*

   19 Parameters Is All You Need: Tiny Neural Networks for Particle Physics

   Alexander Bogatskiy🇺🇸 · Timothy Hoffman🇺🇸 · Jan T. Offermann🇺🇸

   As particle accelerators increase their collision rates, and deep learning solutions prove their viability, there is a growing need for lightweight and fast neural network architectures for low-latency tasks such as triggering. We examine the potential of one recent Lorentz- and permutation-symmetric architecture, PELICAN, and present its instances with as few as 19 trainable parameters that outperform generic architectures with tens of thousands of parameters when compared on the binary classification task of top quark jet tagging.

   hep-phcs.LGhep-ex9 citations
3. 03*

   Nuclear modification factors and the Cronin effect

   Thomas A. Trainor🇺🇸

   Nuclear modification factors (NMFs) applied to A-B collision systems consist of $p_t$ spectrum ratios rescaled by an estimated number of nucleon-nucleon binary collisions. Interest in NMFs is motivated by possible modification (suppression?) of jet production in more-central A-B collisions conjectured to arise from a deconfined quark-gluon plasma or QGP. Interpretation of NMFs is complicated by the so-called Cronin effect wherein similar ratios derived from fixed-target p-A data exhibited suppression at lower $p_t$ and enhancement at higher $p_t$ with increasing atomic weight A. This presentation describes precision analysis of identified-hadron spectra from 5 TeV $p$-Pb collisions that accurately isolates the entire jet contribution. Evolution of NMF spectrum ratios with $p$-Pb centrality is interpreted in terms of variation of corresponding jet contributions to spectra. The same method is then applied to Chicago-Princeton fixed-target spectrum data from the seventies wherein the Cronin effect was first observed. Soft and hard particle densities vary as fixed powers of $A$. Inferred jet contributions are quantitatively consistent with extrapolation from higher energies. The Cronin effect is a simple result of rescaling particle-density spectra by factor $1/A^{1/3}$.

   hep-ph0 citations
4. 04*

   The effective QCD running coupling constant and a Dirac model for the charmonium spectrum

   M. De Sanctis🇨🇴

   The QCD effective charge extracted from the experimental data is used to construct the vector interaction of a Dirac relativistic model for the charmonium spectrum. The process required to fit the spectrum is discussed and the relationship with a previous study of the vector interaction is analyzed.

   hep-phActa Phys.Polon.B(2023)·4 citations
5. 05*

   Dyson-Schwinger equations towards cold-dense QCD matter with improved truncations

   Zhan Bai🇨🇳 · Yu-Xin Liu🇨🇳

   We take the Dyson-Schwinger equation (DSE) approach of QCD to study the phase transition and the equation of state of cold dense matter. Besides the bare vertex and Gauss gluon model, we take into account an improved truncation scheme, the CLRQ vertex and infrared-constant gluon model. For the dynamical chiral symmetry breaking solution of the DSE, we require that the emergence of quark number density to be at the chemical potential for the nuclear liquid-gas phase transition to take place, by incorporating a chemical potential dependent modification factor to the gluon model. The result shows that our modified scheme can not only describe the phase transition of the cold dense matter well but also the deduced equation of state of the matter can describe the recent astronomical observations consistently.

   hep-phnucl-th0 citations
6. 06*

   Generation of $\gamma$ photons with extremely large orbital angular momenta

   Ren-Tong Guo🇨🇳 · Mamutjan Ababekri🇨🇳 · Qian Zhao🇨🇳 · Yousef I. Salamin🇦🇪 · Liang-Liang Ji🇨🇳 · Zhi-Gang Bu🇨🇳 · Zhong-Feng Xu🇨🇳 · Xiu-Feng Weng🇨🇳 · Jian-Xing Li🇨🇳

   Vortex $\gamma$ photons, which carry large intrinsic orbital angular momenta (OAM), have significant applications in nuclear, atomic, hadron, particle and astro-physics, but their production remains unclear. In this work, we investigate the generation of such photons from nonlinear Compton scattering of circularly polarized monochromatic lasers on vortex electrons. We develop a quantum radiation theory for ultrarelativistic vortex electrons in lasers by using the harmonics expansion and spin eigenfunctions, which allows us to explore the kinematical characteristics, angular momentum transfer mechanisms, and formation conditions of vortex $\gamma$ photons. The multiphoton absorption of electrons enables the vortex $\gamma$ photons, with fixed polarizations and energies, to exist in mixed states comprised of multiple harmonics. Each harmonic represents a vortex eigenmode and has transverse momentum broadening due to transverse momenta of the vortex electrons. The large topological charges associated with vortex electrons offer the possibility for $\gamma$ photons to carry adjustable OAM quantum numbers from tens to thousands of units, even at moderate laser intensities. $\gamma$ photons with large OAM and transverse coherence length can assist in influencing quantum selection rules and extracting phase of the scattering amplitude in scattering processes.

   hep-phPRA(2024)·10 citations
7. 07*

   Diffusion model approach to simulating electron-proton scattering events

   Peter Devlin🇺🇸 · Jian-Wei Qiu🇺🇸 · Felix Ringer🇺🇸 · Nobuo Sato🇺🇸

   Generative AI is a fast-growing area of research offering various avenues for exploration in high-energy nuclear physics. In this work, we explore the use of generative models for simulating electron-proton collisions relevant to experiments like CEBAF and the future Electron-Ion Collider (EIC). These experiments play a critical role in advancing our understanding of nucleons and nuclei in terms of quark and gluon degrees of freedom. The use of generative models for simulating collider events faces several challenges such as the sparsity of the data, the presence of global or event-wide constraints, and steeply falling particle distributions. In this work, we focus on the implementation of diffusion models for the simulation of electron-proton scattering events at EIC energies. Our results demonstrate that diffusion models can accurately reproduce relevant observables such as momentum distributions and correlations of particles, momentum sum rules, and the leading electron kinematics, all of which are of particular interest in electron-proton collisions. Although the sampling process is relatively slow compared to other machine learning architectures, we find diffusion models can generate high-quality samples. We foresee various applications of our work including inference for nuclear structure, interpretable generative machine learning, and searches of physics beyond the Standard Model.

   hep-phhep-exnucl-thPRD(2024)·16 citations
8. 08*

   Electron EDM and LFV decays in the light of Muon $(g-2{)}_{\mu }$ with U(2) flavor symmetry

   Morimitsu Tanimoto🇯🇵 · Kei Yamamoto🇯🇵

   We study the interplay of New Physics (NP) among the lepton magnetic moment, the lepton flavor violation (LFV) and the electron electric dipole moment (EDM) in light of recent data of the muon $(g-2{)}_{\mu }$. The NP is discussed in the leptonic dipole operator with the $U(2)$ flavor symmetry of the charged leptons, where possible CP violating phases of the three family space are taken into account. It is remarked that the third-family contributes significantly to the LFV decay, $\mu \to e\gamma$, and the electron EDM. The experimental upper-bound on $\mu \to e\gamma$ decay gives a severe constraint on the parameters of the flavor model. The predicted electron EDM is rather large due to the CP violating phases in the three family space. In addition, we also study $(g-2{)}_{e,\tau }$ of the electron and tauon, and EDMs of the muon and tauon as well as the $\tau \to e\gamma$ and $\tau \to \mu \gamma$ decays. The ${\tau }_R\to {\mu }_L\gamma$ decay is predicted to be close to the experimental upper-bound.

   hep-phEPJC(2024)·4 citations
9. 09*

   Constructing the Equation of State of QCD in a functional QCD based scheme

   Yi Lu🇨🇳 · Fei Gao🇨🇳 · Bao-Chi Fu🇨🇳 · Hui-Chao Song🇨🇳 · Yu-Xin Liu🇨🇳

   We construct the equation of state (EoS) of QCD based on the finite chemical potential information from the functional QCD approaches, with the assistance of the lattice QCD EoS. The obtained EoS is consistent with the up-to-date estimations of the QCD phase diagram, including a phase transition temperature at zero chemical potential of $T=155$ MeV, the curvature of the transition line $\kappa =0.016$ and also a critical end point at $(T,{\mu }_B)=(118,600)$ MeV. In specific, the phase diagram mapping is achieved by incorporating the order parameters into the EoS, namely the dynamical quark mass for the chiral phase transition together with the Polyakov loop parameter for the deconfinement phase transition. We also implement the EoS in hydrodynamic simulations to compute the particle yields, ratios and collective flow, and find that our obtained EoS agrees well with the commonly used one based on the combination of lattice QCD simulation and hadron resonance gas model.

   hep-phnucl-exnucl-thPRD(2024)·16 citations
10. 10*

    The ${\nu }_R$-philic scalar dark matter

    Xun-Jie Xu🇨🇳 · Siyu Zhou🇨🇳 · Junyu Zhu🇨🇳

    Right-handed neutrinos (${\nu }_R$) offer an intriguing portal to new physics in hidden sectors where dark matter (DM) may reside. In this work, we delve into the simplest hidden sector involving only a real scalar exclusively coupled to ${\nu }_R$, referred to as the ${\nu }_R$-philic scalar. We investigate the viability of the ${\nu }_R$-philic scalar to serve as a DM candidate, under the constraint that the coupling of ${\nu }_R$ to the standard model is determined by the seesaw relation and is responsible for the observed DM abundance. By analyzing the DM decay channels and solving Boltzmann equations, we identify the viable parameter space. In particular, our study reveals a lower bound ($2.6\times 10^5$ GeV) on the mass of ${\nu }_R$ for the ${\nu }_R$-philic scalar to be DM. The DM mass may vary from sub-MeV to sub-GeV. Within the viable parameter space, monochromatic neutrino lines from DM decay can be an important signal for DM indirect detection.

    hep-phastro-ph.COJCAP(2024)·10 citations
11. 11*

    Classification of three-family flavoured DFSZ axion models that have no domain wall problem

    Peter Cox🇦🇺 · Matthew J. Dolan🇦🇺 · Maaz Hayat🇦🇺 · Andrea Thamm🇦🇺 · Raymond R. Volkas🇦🇺

    We provide an exhaustive classification of three-family DFSZ axion models that have no cosmological domain wall problem. This result is obtained by making the Peccei-Quinn symmetry flavour dependent in certain specific ways, thus reinforcing a possible connection between the strong CP problem and the flavour puzzle. Known DFSZ flavour variants such as the top-specific model emerge as special cases. Key features of the phenomenology of these models are briefly discussed.

    hep-phJHEP(2024)·17 citations
12. 12*

    Bound states from the spectral Bethe-Salpeter equation

    Gernot Eichmann🇦🇹 · Andrés Gómez🇩🇪 · Jan Horak🇩🇪 · Jan M. Pawlowski🇩🇪 · Jonas Wessely🇩🇪 · Nicolas Wink🇩🇪

    We compute the bound state properties of three-dimensional scalar ${\varphi }^4$ theory in the broken phase. To this end, we extend the recently developed technique of spectral Dyson-Schwinger equations to solve the Bethe-Salpeter equation and determine the bound state spectrum. We employ consistent truncations for the two-, three- and four-point functions of the theory that recover the scaling properties in the infinite coupling limit. Our result for the mass of the lowest-lying bound state in this limit agrees very well with lattice determinations.

    hep-phhep-thPRD(2024)·14 citations
13. 13*

    Evolution of colour correlated double parton distributions: a quantitative study

    Markus Diehl🇩🇪 · Florian Fabry🇩🇪 · Peter Ploessl🇩🇪

    Double parton distributions satisfy the same evolution equations as ordinary single-parton densities, provided that the colours of the two partons are uncorrelated. The situation is different for colour correlated parton pairs, where evolution to higher scales results in a suppression by Sudakov double logarithms. We perform a detailed study of evolution for colour correlated double parton distributions, both analytically and numerically, at lowest order and beyond. When the two observed partons originate from the perturbative splitting of a single one, the Sudakov suppression of colour correlations at the cross section level is not as strong as one might expect.

    hep-phJHEP(2024)·8 citations
14. 14*

    SU(3) breaking effect in the $Z_c$ and $Z_{cs}$ states

    Kan Chen🇨🇳

    Based on the hadronic resonance picture, we propose a possible framework to simultaneously describe the resonance parameters of the observed $Z_{cs}$ and $Z_c$ states that are close to the thresholds of the $D^{(\ast )}{\bar{D}}_s^{(\ast )}$ and $D^{(\ast )}{\bar{D}}^{(\ast )}$ systems, respectively. We construct the effective potentials of the $Z_{cs}$ and $Z_c$ states by analogy with the effective potentials of the leading order (LO) and next-to-leading-order (NLO) $N-\bar{N}$ interactions. Then we introduce an SU(3) breaking factor $g_x$ to identify the differences between the effective potentials in the $Z_{cs}$ and $Z_c$ states. We perform two calculations to discuss the differences and similarities of the $Z_{cs}$ and $Z_c$ states. In the first calculation, we adopt the LECs extracted from the experimental $Z_{cs}$ states to calculate the $Z_c$ states, and show that if the $Z_{cs}(4000)$ is the SU(3) partner of the $Z_c(3900)$, then our framework can reproduce the large width difference between the $Z_{cs}(4000)$ and $Z_c(3900)$ by adjusting the SU(3) breaking factor in a reasonable region. Besides, this SU(3) breaking effect also accounts for the absence of a $Z_c$ state with $J^{PC}=1^{++}$, which should be the SU(3) partner of the $Z_{cs}(3985)$. In the second calculation, we separately fit the LECs from the experimental $Z_{cs}$ and $Z_c$ states. We show that these two sets of LECs are very similar to each other, indicating a unified set of LECs that could describe the effective potentials of the $Z_{cs}$ and $Z_c$ states simultaneously. Then we proceed to systematically predict the other possible $Z_{cs}$ and $Z_c$ states that are close to the $D^{(\ast )}{\bar{D}}_s^{(\ast )}$ and $D^{(\ast )}{\bar{D}}^{(\ast )}$ systems, respectively. Further explorations on the $Z_{cs}$ states would be crucial to test our theory.

    hep-phhep-exPRD(2024)·2 citations
15. 15*

    Quantum corrections and the minimal Yukawa sector of $SU(5)$

    Ketan M. Patel🇮🇳 · Saurabh K. Shukla🇮🇳

    It is well-known that the $SU(5)$ grand unified theory, with the standard model quarks and leptons unified in $\overline{5}$ and $10$ and the electroweak Higgs doublet residing in $5$ dimensional representations, leads to relation, $Y_d=Y_e^T$, between the Yukawa couplings of the down-type quarks and the charged leptons. We show that this degeneracy can be lifted in a phenomenologically viable way when quantum corrections to the tree-level matching conditions are taken into account in the presence of one or more copies of gauge singlet fermions. The 1-loop threshold corrections arising from heavy leptoquark scalar and vector bosons, already present in the minimal model, and heavy singlet fermions can lead to realistic Yukawa couplings provided their masses differ by at least two orders of magnitude. The latter can also lead to a realistic light neutrino mass spectrum through the type I seesaw mechanism if the colour partner of the Higgs stays close to the Planck scale. Most importantly, our findings demonstrate the viability of the simplest Yukawa sector when quantum corrections are considered and sizeable threshold effects are present.

    hep-phhep-thPRD(2024)·5 citations
16. 16*

    The two-body strong decays of the fully-charm tetraquark states

    Zhi-Gang Wang🇨🇳 · Xiao-Song Yang🇨🇳

    We study the hadronic coupling constants in the two-body strong decays of the fully-charm tetraquark states with the $J^{PC}=0^{++}$, $1^{+-}$ and $2^{++}$ via the QCD sum rules based on rigorous quark-hadron duality. Then we obtain the hadronic coupling constants and partial decay widths therefore total decay widths, which support assigning the $X(6552)$ as the first radial excitation of the scalar tetraquark state. And other predictions can be used to diagnose exotic states in the future.

    hep-phAAPPS Bull.(2024)·24 citations
17. 17*

    Undecay

    Eugenio Megias🇪🇸 · Manuel Perez-Victoria🇪🇸 · Mariano Quiros🇪🇸

    Unstable particles decay sooner or later, so they are not described by asymptotic one-particle states and they should not be included as independent states in unitarity relations such as the optical theorem. The same applies to any countable collection of unstable particles. We show that the behaviour of unparticle stuff, that is, a continuous collection of particles with different masses and common decay channels, is pretty different: it has a non-vanishing probability of surviving for ever and the corresponding asymptotic states must be taken into account to comply with unitarity. We also discuss compressed spectra and the transition from the discrete to the continuous case.

    hep-phhep-thJHEP(2024)·4 citations
18. 18*

    Strong decays of the $\varphi (2170)$ as a fully-strange tetraquark state

    Yi-Wei Jiang🇨🇳 · Wei-Han Tan🇨🇳 · Hua-Xing Chen🇨🇳 · Er-Liang Cui🇨🇳

    We study strong decays of the $\varphi (2170)$, along with its possible partner $X(2436)$, as two fully-strange tetraquark states of $J^{PC}=1^{--}$. We consider seven decay channels: $\varphi \eta$, $\varphi {\eta }^{\prime }$, $\varphi f_0(980)$, $\varphi f_1(1420)$, $h_1(1415)\eta$, $h_1(1415){\eta }^{\prime }$, and $h_1(1415)f_1(1420)$. Some of these channels are kinematically possible, and we calculate their relative branching ratios through the Fierz rearrangement. Future experimental measurements on these ratios can be useful in determining the nature of the $\varphi (2170)$ and $X(2436)$. The $\varphi (2170)$ has been observed in the $\varphi f_0(980)$, $\varphi \eta$, and $\varphi {\eta }^{\prime }$ channels, and we propose to further examine it in the $h_1(1415)\eta$ channel. Evidences of the $X(2436)$ have been observed in the $\varphi f_0(980)$ channel, and we propose to verify whether this structure exists or not in the $\varphi \eta$, $\varphi {\eta }^{\prime }$, $h_1(1415)\eta$, and $h_1(1415){\eta }^{\prime }$ channels.

    hep-phSymmetry(2024)·9 citations
19. 19*

    CP-like Symmetry with Discrete and Continuous Groups and CP Violation/Restoration

    Hiroshi Ohki🇯🇵 · Shohei Uemura🇯🇵

    We study physical implications of general CP symmetry including CP-like symmetry. Various scattering amplitudes of CP asymmetry are calculated in CP-like symmetric models. We explicitly show that the CP-like transformation leads to a specific relation between different CP asymmetries. The resultant relation is similar to the one obtained in GUT baryogenesis and sphaleron processes, where we also obtain a required condition for generating particle number asymmetry in CP-like symmetric models. In addition, we propose a generalization of a CP-like transformation for continuous symmetry groups. Since the CP transformation is an outer automorphism, which depends on the internal symmetry group, it turns out that the physical CP and CP-like symmetries can be mutually converted through the spontaneous symmetry breaking (SSB) of the internal symmetry. We investigate properties of physical CP asymmetry in both CP and CP-like symmetric phases, and find that the spontaneous CP violation and restoration can be observed even in models with continuous groups. We demonstrate that CP-like symmetric models with continuous Lie groups can be naturally realized in physical CP symmetric models through the SSB.

    hep-phhep-thJHEP(2024)·4 citations
20. 20*

    Primordial Black Holes with QCD Color Charge

    Elba Alonso-Monsalve🇺🇸 · David I. Kaiser🇺🇸

    We describe a realistic mechanism whereby black holes with significant QCD color charge could have formed during the early universe. Primordial black holes (PBHs) could make up a significant fraction of the dark matter if they formed well before the QCD confinement transition. Such PBHs would form by absorbing unconfined quarks and gluons, and hence could acquire a net color charge. We estimate the number of PBHs per Hubble volume with near-extremal color charge for various scenarios, and discuss possible phenomenological implications.

    hep-phastro-ph.COgr-qchep-thPRL(2024)·22 citations
21. 21*

    Light Dilaton in Rare Meson Decays and Extraction of its CP Property

    Sudhakantha Girmohanta🇨🇳 · Yuichiro Nakai🇨🇳 · Yoshihiro Shigekami🇨🇳 · Kohsaku Tobioka🇺🇸

    The dilaton $\varphi$ is a pseudo-Nambu-Goldstone boson associated with the spontaneous breaking of scale invariance in a nearly conformal theory, and couples to the trace of the stress-energy tensor. We analyze experimental constraints on a light dilaton with mass in the MeV-GeV range from rare meson decays. New model-independent inclusive bounds for the $b\to s\varphi$ transition largely exclude the parameter space of a light dilaton that could explain the muon $g-2$ anomaly. Despite similarities between a dilaton and a Higgs-portal scalar, the dilaton-photon coupling is enhanced compared to the Higgs-portal scalar due to contributions from loops of the conformal sector. Consequently, the shortened lifetime of the dilaton relaxes bounds from $K\to \pi$ + invisible searches at the NA62 experiment and constraints from the Big Bang Nucleosynthesis. We utilize this fact to search for the dilaton signature at a lepton collider such as the ongoing Belle II experiment. Further, we demonstrate how to extract the CP property of the dilaton using the variation of the differential cross-section of $e^{+}{e}^{-}\to e^{+}{e}^{-}\varphi$ with the azimuthal angle between the outgoing leptons.

    hep-phhep-exJHEP(2024)·9 citations
22. 22*

    Instanton effects in twist-3 generalized parton distributions

    June-Young Kim🇺🇸 · Christian Weiss🇺🇸

    The instanton vacuum picture is used to study hadronic matrix elements of the twist-3 (dimension-4, spin-1) QCD operators measuring the quark spin density and spin-orbit correlations. The QCD operators are converted to effective operators in the low-energy effective theory emerging after chiral symmetry breaking, in a systematic approach based on the diluteness of the instanton medium and the $1/N_c$ expansion. The instanton fields induce spin-flavor-dependent "potential" terms in the effective operators, complementing the "kinetic" terms from the quark field momenta. As a result, the effective operators obey the same equation-of-motion relations as the original QCD operators. The spin-orbit correlations are qualitatively different from naive quark model expectations.

    hep-phPLB(2024)·9 citations
23. 23*

    Precise Cosmological Constraints from BOSS Galaxy Clustering with a Simulation-Based Emulator of the Wavelet Scattering Transform

    Georgios Valogiannis🇺🇸 · Sihan Yuan · Cora Dvorkin🇺🇸

    We perform a reanalysis of the BOSS CMASS DR12 galaxy dataset using a simulation-based emulator for the Wavelet Scattering Transform (WST) coefficients. Moving beyond our previous works, which laid the foundation for the first galaxy clustering application of this estimator, we construct a neural net-based emulator for the cosmological dependence of the WST coefficients and the 2-point correlation function multipoles, trained from the state-of-the-art suite of \textsc{AbacusSummit} simulations combined with a flexible Halo Occupation Distribution (HOD) galaxy model. In order to confirm the accuracy of our pipeline, we subject it to a series of thorough internal and external mock parameter recovery tests, before applying it to reanalyze the CMASS observations in the redshift range $0.46<z<0.57$. We find that a joint WST + 2-point correlation function likelihood analysis allows us to obtain marginalized 1$\sigma$ errors on the $\Lambda$CDM parameters that are tighter by a factor of $2.5-6$, compared to the 2-point correlation function, and by a factor of $1.4-2.5$ compared to the WST-only results. This corresponds to a competitive $0.9\%$, $2.3\%$ and $1\%$ level of determination for parameters ${\omega }_c$, ${\sigma }_8$ $\&$ $n_s$, respectively, and also to a $0.7\%$ $\&$ $2.5\%$ constraint on derived parameters h and $f(z){\sigma }_8(z)$, in agreement with the \textit{Planck} 2018 results. Our results reaffirm the constraining power of the WST and highlight the exciting prospect of employing higher-order statistics in order to fully exploit the power of upcoming Stage-IV spectroscopic observations.

    ↳ astro-ph.COastro-ph.GAastro-ph.IMhep-ph+1PRD(2024)·47 citations
24. 24*

    The renormalization of the shell-model GT operator starting from effective field theory for nuclear systems

    L. Coraggio🇮🇹 · N. Itaco🇮🇹 · G. De Gregorio🇮🇹 · A. Gargano🇮🇹 · Z. H. Cheng🇨🇳 · Y. Z. Ma🇨🇳 · F. R. Xu🇨🇳 · M. Viviani🇮🇹

    For the first time, we approach in this work the problem of the renormalization of the Gamow-Teller decay operator for nuclear shell-model calculations by way of many-body perturbation theory, starting from a nuclear Hamiltonian and electroweak currents derived consistently by way of the chiral perturbation theory. These are the inputs we need to construct microscopically the effective shell-model Hamiltonians and decay operators. The goal is to assess the role of both electroweak currents and many-body correlations as the origins of the well-known problem of the quenching of the axial coupling constant gA. To this end, the calculation of observables related to the Gamow-Teller transitions has been performed for several nuclear systems outside the 40Ca and 56Ni closed cores and compared with the available data.

    ↳ nucl-thhep-exhep-phnucl-exPRC(2024)·25 citations
25. 25*

    Space-time structure of particle emission and femtoscopy scales in ultrarelativistic heavy-ion collisions

    Yu. M. Sinyukov · V. M. Shapoval · M. D. Adzhymambetov

    The analysis of the spatiotemporal picture of particle radiation in relativistic heavy-ion collisions in terms of correlation femtoscopy scales, emission and source functions allows one to probe the character of evolution of the system created in the collision. Realistic models, like the integrated hydrokinetic model (iHKM), used in the present work, are able to simulate the entire evolution process of strongly interacting matter produced in high-energy nuclear collision. The mentioned model describes all the stages of the system's evolution, including formation of the very initial state and its consequent gradual thermalization, hydrodynamic expansion and afterburner hadronic cascade, that can help researchers to figure out the specific details of the process and better understand the formation mechanisms of certain observables. In the current paper we investigate the behavior of the pion and kaon interferometry radii and their connection with emission functions in ultrarelativistic heavy-ion collisions at the Large Hadron Collider within iHKM. We are focusing on the study of the emission time scales at different energies for both particle species (pions and kaons) aiming to get deeper insight into relation of these scales and the peculiarities of the mentioned system's collective expansion and decay with the experimentally observed femtoscopy radii. One of our main interests is the problem of the total system's lifetime estimation based on the femtoscopy analysis.

    ↳ nucl-thhep-exhep-phnucl-exUniverse(2023)·5 citations
26. 26*

    Baryons as Vortexes on the ${\eta }^{\prime }$ Domain Wall

    Fan Lin🇨🇳 · Yong-Liang Ma🇨🇳

    We show that the recent construction of $N_f=1$ baryons on the ${\eta }^{\prime }$ domain wall can be understood as vortexes of the principal effective theory -- the Chern-Simons-Higgs theory -- on a 2+1-dimensional sheet. This theory has a series of vertex solutions, and the vortex with unit topological charge naturally spins $N_c/2$, which coincides with the spin of the one-flavor baryon in QCD. Since the $N_c$ scaling of the vortexes is the same as that of baryons, baryons can be regarded as vortexes. By virtue of the particle-vortex symmetry, the dual Zhang-Hansson-Kivelson theory indicates that the quark carries topological charge $1/N_c$ and obeys fractional statistics. The generalization to arbitrary $N_f$ is also discussed.

    ↳ hep-thhep-phnucl-thJHEP(2024)·10 citations
27. 27*

    Relating ${\beta }_{\ast }^{\prime }$ and ${\gamma }_{Q\ast }^{\prime }$ in the $\mathcal{N}=1$ SQCD Conformal Window

    Mikhail Shifman🇺🇸 · Roman Zwicky🇬🇧

    In this note we show that ${\beta }_{\ast }^{\prime }$, the $\beta$-function slopes in the electric and magnetic theories are equal at the corresponding infrared fixed points. This follows from the scaling of the correlators of the trace of the energy momentum tensors. The slopes ${\beta }_{\ast }^{\prime }$ determine the scaling dimensions. Our paper can be considered as a commentary to Anselmi et al. [1] -- it proposes an improved derivation not based on a rather contrived construction by Kutasov et al. [2]. As a byproduct we note that ${\gamma }_{Q^{\ast }}^{\prime }$ -- the slopes of the matter superfield anomalous dimension -- vanish at both edges of the conformal window where one of the dual theories is strongly coupled. Finally, we determine the two-coupling magnetic fixed point at weak coupling correcting the result of [3]}.

    ↳ hep-thhep-phPRD(2023)·9 citations
28. 28*

    Probing photon-ALP oscillations from the MAGIC observations of FSRQ QSO B1420+326

    Bhanu Prakash Pant🇮🇳

    At the beginning of 2020, MAGIC reported a very-high-energy (VHE) flaring activity from the FSRQ QSO B1420+326. It is now the fourth known most distant blazar (z=0.682) with an observed VHE gamma-ray emission. In this work, we investigate the effect of photon-axionlike particle (ALP) oscillations in the gamma-ray spectra measured by Fermi-LAT and MAGIC around the flaring state. We set 95% C.L. upper limit on the ALP parameters and obtain a constraint on the photon-ALP coupling constant $g_{a\gamma }<2\times 10^{-11}$ GeV${}^{-1}$ for ALP masses $m_a\sim 10^{-10}-10^{-9}$ eV. Assuming the hadronic origin of VHE photons, we also estimate the expected neutrino flux from this source and the contribution to diffuse neutrino flux from QSO B1420+326-like FSRQs at sub-PeV energies. Furthermore, we study the implications of photon-ALP oscillations on the counterpart $\gamma$-rays of the sub-PeV neutrinos. Finally, we investigate a viable scenario of invisible neutrino decay to ALPs on the gamma-ray spectra and diffuse $\gamma$-ray flux at sub-PeV energies. Interestingly, we find that for the choice of neutrino lifetime ${\tau }_2/m_2=10^3$ s eV${}^{-1}$, the $\gamma$-ray flux has a good observational sensitivity towards LHAASO-KM2A.

    ↳ astro-ph.HEhep-phPRD(2024)·9 citations
29. 29*

    Optimal Inflationary Potentials

    Tomás Sousa🇬🇧 · Deaglan J. Bartlett🇫🇷 · Harry Desmond🇬🇧 · Pedro G. Ferreira🇬🇧

    Inflation is a highly favoured theory for the early Universe. It is compatible with current observations of the cosmic microwave background and large scale structure and is a driver in the quest to detect primordial gravitational waves. It is also, given the current quality of the data, highly under-determined with a large number of candidate implementations. We use a new method in symbolic regression to generate all possible simple scalar field potentials for one of two possible basis sets of operators. Treating these as single-field, slow-roll inflationary models we then score them with an information-theoretic metric ("minimum description length") that quantifies their efficiency in compressing the information in current data. We explore two possible priors on the parameter space of potentials, one related to the functions' structural complexity and one that uses a Katz back-off language model to prefer functions that may be theoretically motivated. This enables us to identify the inflaton potentials that optimally balance simplicity with accuracy at explaining current data, which may subsequently find theoretical motivation. Our exploratory study opens the door to extraction of fundamental physics directly from data, and may be augmented with more refined theoretical priors in the quest for a complete understanding of the early Universe.

    ↳ astro-ph.COcs.LGgr-qchep-ph+1PRD(2024)·22 citations
30. 30*

    Quasithermal GeV neutrinos from neutron-loaded magnetized outflows in core-collapse supernovae: spectra and light curves

    Jose Alonso Carpio🇺🇸 · Nick Ekanger🇺🇸 · Mukul Bhattacharya🇺🇸 · Kohta Murase🇺🇸 · Shunsaku Horiuchi🇺🇸

    Rapidly rotating and strongly magnetized protoneutron stars (PNSs) created in core-collapse supernovae can drive relativistic magnetized winds. Ions and neutrons can be co-accelerated while they remain coupled through elastic collisions. We investigate the nucleosynthesis and subsequent nuclear disintegration, and find that relativistic neutrons can be generated in such magnetized winds. Upon eventual decoupling, resulting inelastic collisions with ejecta lead to pion production, resulting in $0.1-10\mathrm{GeV}$ neutrinos. Following this scenario presented in Murase, Dasgupta \& Thompson, Phys. Rev. D, 89, 043012 (2014), we numerically calculate the spectra and light curves of quasithermal neutrino emission. In the event of a Galactic supernova, $\sim 10-1000$ neutrino events could be detected with Hyper-Kamiokande, KM3Net-ORCA and IceCube-Upgrade for PNSs with surface magnetic field $B_{\mathrm{dip}}\sim 10^{13-15}\mathrm{G}$ and initial spin period $P_i\sim 1-30\mathrm{ms}$. Successful detection will enable us to study supernovae as multienergy neutrino sources and may provide clues to the roles of PNSs in diverse classes of transients.

    ↳ astro-ph.HEastro-ph.SRhep-phPRD(2024)·9 citations
31. 31*

    Gravitational wave triggered searches for high-energy neutrinos from binary neutron star mergers: prospects for next generation detectors

    Mainak Mukhopadhyay🇺🇸 · Shigeo S. Kimura🇯🇵 · Kohta Murase🇺🇸

    The next generation gravitational wave (GW) detectors -- Einstein Telescope (ET) and Cosmic Explorer (CE) will have distance horizons up to $\mathcal{O}(10)$ Gpc for detecting binary neutron star (BNS) mergers. This will make them ideal for triggering high-energy neutrino searches from BNS mergers at the next generation neutrino detectors, such as IceCube-Gen2. We calculate the distance limits as a function of the time window of neutrino analysis, up to which meaningful triggers from the GW detectors can be used to minimize backgrounds and collect a good sample of high-energy neutrino events at the neutrino detectors, using the sky localization capabilities of the GW detectors. We then discuss the prospects of the next generation detectors to work in synergy to facilitate coincident neutrino detections or to constrain the parameter space in the case of non-detection of neutrinos. We show that good localization of GW events, which can be achieved by multiple third generation GW detectors, is necessary to detect a GW-associated neutrino event or put a meaningful constraint ($\sim 3\sigma$ confidence level) on neutrino emission models. Such an analysis can also help constrain physical models and hence provide insights into neutrino production mechanisms in binary neutron star mergers.

    ↳ astro-ph.HEgr-qchep-phPRD(2024)·15 citations
32. 32*

    Effective Action Approach for Preheating

    Bin Xu🇺🇸 · Wei Xue🇺🇸

    We present a semiclassical non-perturbative approach for calculating the preheating process at the end of inflation. Our method involves integrating out the decayed particles within the path integral framework and subsequently determining world-line instanton solutions in the effective action. This enables us to obtain the effective action of the inflaton, with its imaginary part linked to the phenomenon of particle creation driven by coherent inflaton field oscillations. Additionally, we utilize the Bogoliubov transformation to investigate the evolution of particle density within the medium after multiple inflaton oscillations. We apply our approach to various final state particles, including scalar fields, tachyonic fields, and gauge fields. The non-perturbative approach provides analytical results for preheating that are in accord with previous methods.

    ↳ hep-thastro-ph.COhep-phJCAP(2024)·1 citation

* 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.