Tue·Mar 19, 2024Tuesday·March 19, 2024

1. 01*

   Quark anomalous magnetic moment in an extreme magnetic background from perturbative QCD

   Eduardo S. Fraga🇧🇷 · Leticia F. Palhares🇧🇷 · Cristian Villavicencio🇨🇱

   We compute the one-loop QCD correction to the photon-quark-antiquark vertex in an extremely strong magnetic background, i.e., one in which $\sqrt{eB}$ is much larger than all other mass scales. We resort to the lowest-Landau level approximation, and consider on shell fermions. We find that the total magnetic moment is such that the anomalous magnetic moment contributes to the electric part $\sim i{E}_3{\sigma }_3$, the other contributions to $\mathbf{B}\cdot \mathbf{\sigma }$ and $i\mathbf{E}\cdot {\mathbf{\sigma }}_{\perp }$ being completely suppressed. We show results for the anomalous magnetic moment of quarks up and down, scaled by their values in the vacuum, as a function of the external magnetic field, considering dressed gluons and a renormalization scale ${\mu }_{\overline{\mathrm{MS}}}=\sqrt{|eB|}$.

   hep-phnucl-thPRD(2024)·8 citations
2. 02*

   Three lectures on the Curci-Ferrari model

   Urko Reinosa🇫🇷

   In these lectures, we review the status of the Curci-Ferrari model as a phenomenological approach to Landau gauge-fixed YM theories in the infrared. More precisely, after discussing some of the general properties of the model, we explain in full detail the evaluation of the one-loop two-point correlators that allowed for a successful comparison to the corresponding Landau-gauge lattice data. We also review the renormalization group flow of the model which controls its fate at high and low momentum scales.

   hep-phhep-th5 citations
3. 03*

   Electroweak Monopole-Antimonopole Pair Production at LHC

   Petr Benes🇨🇿 · Filip Blaschke🇨🇿 · Y. M. Cho🇰🇷

   The monopole production at LHC crucially depends on the monopole production mechanism. We show that, if the monopole production mechanism at LHC is the thermal fluctuation of the Higgs vacuum as the early universe did, it is practically impossible for LHC to produce the monopole, even with the future FCC energy upgrade. This is because the temperature of the p-p fireball is simply too low to produce the monopole. But if the monopole production mechanism is the Drell-Yan and/or Schwinger mechanism, the 14 TeV LHC could produce the monopole in the form of the monopolium of mass around 5,7 TeV even when the monopole mass becomes 11 TeV. Or, it could produce the monopole when the mass is less than 7 TeV. Our result tells that, if the monopole production mechanism at LHC becomes the thermal fluctuation, searching for the remnant monopoles produced in the early universe could be the only way to detect the electroweak monopole. We discuss the physical implications of our result.

   hep-ph3 citations
4. 04*

   Power corrections to the modified QCD perturbative series based on conformal mapping of the Borel plane

   Irinel Caprini🇷🇴

   Modifications of the QCD perturbative expansions by the subtraction of the dominant infrared renormalon have been proposed recently as attempts to solve the long-standing discrepancy between fixed-order and contour-improved perturbation theory for the hadronic $\tau$ decays. In this approach, the modified perturbative series is supplemented by a modified gluon condensate in the operator product expansion of the Adler function. Motivated by these works, we revisited recently a formulation of the QCD perturbation theory, proposed some time ago, which takes into account the renormalons by means of the conformal mapping of the Borel plane. One expects that the modified perturbative series obtained in this framework should be accompanied by modified power-suppressed nonperturbative corrections. However, in the previous studies the focus was on the perturbative series and the question of the possible power corrections has not been considered. In the present paper, we investigate for the first time this problem. Using techniques from the mathematical resurgence theory, we derive the expression of the dominant power correction to the perturbative series obtained by conformal mapping of the Borel plane, and discuss its implications for phenomenological applications.

   hep-phPRD(2024)·3 citations
5. 05*

   Resolving the W-Boson Mass in the Lepton Specific Two Higgs Doublet Model

   Ali Cici · Huseyin Dag🇹🇷

   In 2022, the CDF Collaboration reported the $W$-boson mass, $M_W=80.4335\pm 0.0094\mathrm{GeV}$, which deviates from the Standard Model (SM) prediction, $M_W^{\mathrm{SM}}=80.357\pm 0.006\mathrm{GeV}$, by about $7\sigma$. By contrast, the CMS Collaboration obtained $M_W=80.3602\pm 0.0099\mathrm{GeV}$, very close to the SM global electroweak fit value of $\sim 80.357\mathrm{GeV}$. Motivated by this situation, we reassess the $W$-boson mass within the Lepton-Specific Two Higgs Doublet Model (LS-2HDM). We perform random scans (generated with SARAH 4.13.0 and evaluated with SPheno 4.0.3) and confront the results with up-to-date theoretical and experimental constraints. In the LS-2HDM, if $h_1$ is the SM-like Higgs at $m_{h_1}\simeq 125$ GeV with $|\cos (\beta -\alpha )|\lesssim 0.06$, $17\lesssim \tan \beta \lesssim 39$, $144\lesssim m_{h_2}\lesssim 414$ GeV, and $435\lesssim m_{A,H^{\pm }}\lesssim 685$ GeV, the model reproduces the 2024 CMS $W$-boson mass within $3\sigma$. Solutions near the 2022 CDF value, $M_W=80.4335\pm 0.0094\mathrm{GeV}$, survive; however, after applying all constraints, including HiggsTools, they approach it at best within $\lesssim 2\sigma$. Our findings emphasize that the LS-2HDM favors the CMS results consistently with the current experimental results. On the other hand, while one can accommodate also the CDF results in this model theoretically, up-to-date electroweak precision bounds on the oblique parameters $(S,T,U)$ together with the SM-like Higgs and LFU constraints exclude these solutions and our results for $W-$boson mass can be only as close as about $2\sigma$ to the CDF results.

   hep-phhep-exChin.Phys.C C(2026)·2 citations
6. 06*

   Radiative transitions of ${\chi }_{{}_{cJ}}\to \psi \gamma$ and ${\chi }_{{}_{bJ}}\to {\rm Y}\gamma$

   Su-Yan Pei🇨🇳 · Wei Li🇨🇳 · Tianhong Wang🇨🇳 · Guo-Li Wang🇨🇳

   In the framework of instantaneous Bethe-Salpeter equation, according to the $J^{PC}$ of quarkonia, we find that their wave functions all contain multiple partial waves, rather than pure waves. In the radiative electromagnetic transitions ${\chi }_{{}_{cJ}}$$\to$$\gamma \psi$ and ${\chi }_{{}_{bJ}}$$\to$$\gamma {\rm Y}$ ($J=0,1,2$), the main wave of quarkonium gives the non-relativistic contribution, while other waves provide the relativistic corrections. Our results indicate that the relativistic effect of charmonium, especially highly excited states, is significant. Such as the relativistic effects of ${\chi }_{{}_{cJ}}(2P)\to \gamma \psi (1S)$ ($J=0,1,2$) are $\{49.7\%,30.9\%,37.5\%\}$, much larger than the corresponding $\{17.8\%,7.08\%,12.9\%\}$ of ${\chi }_{{}_{bJ}}(2P)\to \gamma {\rm Y}(1S)$. The decay of ${\chi }_{{}_{cJ}}(2P)\to \gamma \psi$ can be used to distinguish between ${\chi }_{{}_{c0}}(3860)$ and ${\chi }_{{}_{c0}}(3915)$, which particle is the charmonium ${\chi }_{{}_{c0}}(2P)$. Although our result of ${\chi }_{{}_{c1}}(3872)$$\to$$\gamma \psi (2S)$ is consistent with data, but the one of ${\chi }_{{}_{c1}}(3872)$$\to$$\gamma \psi (1S)$ is much larger than data, so whether ${\chi }_{{}_{c1}}(3872)$ is the conventional ${\chi }_{{}_{c1}}(2P)$ remains an open question. The undiscovered ${\rm Y}(1D)$ and ${\rm Y}(2D)$ have large production rates in decays of ${\chi }_{{}_{b0}}(2P)\to \gamma {\rm Y}(1D)$ and ${\chi }_{{}_{bJ}}(3P)\to \gamma {\rm Y}(2D)$ ($J=0,1$), respectively. To search for ${\chi }_{{}_{bJ}}(3P)$ $(J=0,1,2)$, the most competitive channels are the decays ${\chi }_{{}_{bJ}}(3P)\to \gamma {\rm Y}(3S)$. And the best way to find ${\chi }_{{}_{b2}}(1F)$ is to search for the decay of ${\chi }_{{}_{b2}}(1F)\to \gamma {\rm Y}(1D)$.

   hep-phhep-exJHEP(2024)·6 citations
7. 07*

   The masses and decay widths of the $S$-wave ${\Lambda }_c{\bar{\Lambda }}_c$ bound states

   Shi-Ji Cao🇨🇳 · Jing-Juan Qi🇨🇳 · Xin-Heng Guo🇨🇳 · Zhen-Yang Wang🇨🇳

   In this work, we investigate possible bound states of the ${\Lambda }_c{\bar{\Lambda }}_c$ system in the Bethe-Salpeter formalism in the ladder and instantaneous approximations. By numerically solving the Bethe-Salpeter equation, we confirm the existence of ${\Lambda }_c{\bar{\Lambda }}_c$ bound states with quantum numbers $J^{PC}=0^{-+}$ and $J^{PC}=1^{--}$. We further investigate the partial decay widths of the ${\Lambda }_c{\bar{\Lambda }}_c$ bound states into $N\bar{N}$, $D\bar{D}$, $D{\bar{D}}^{\ast }$, $D^{\ast }{\bar{D}}^{\ast }$, $\pi \bar{\pi }$, and $K\bar{K}$. Our results indicate that the decay width of the ${\Lambda }_c{\bar{\Lambda }}_c$ bound state with $J^{PC}=1^{--}$ is much larger than that with $J^{PC}=0^{-+}$, and among their decay channels, the $D{\bar{D}}^{\ast }$ final state is the main decay mode. We suggest experiments to search for the ${\Lambda }_c{\bar{\Lambda }}_c$ bound states in the $D{\bar{D}}^{\ast }$ final state.

   hep-phPRD(2024)·4 citations
8. 08*

   A note on the dimensional regularization and the on-mass-shell renormalization in the two-loop order

   Kiyoshi Kato

   The use of the dimensional regularization in the on-mass-shell renormalization scheme sometimes fails to locally cancel the ultraviolet divergence for a class of diagrams in the two-loop order. The mechanism is discussed based on an example with explicit computation.

   hep-phKogakuin Daigaku Kenkyuronso(ISSN 2186663…·0 citations
9. 09*

   $T_7$ Flavor Symmetry gym: The Key to Unlocking the Neutrino Mass Puzzle

   M.W. Aslam🇵🇰 · A.A. Zafar🇵🇰 · M.N. Aslam🇵🇰 · A.A. Bhatti🇺🇸 · T. Hussain🇵🇰

   Recent research has indicated that the Standard Model (SM), while historically highly effective, is found to be insufficient due to its prediction of zero mass for neutrinos. With the exception of a few, the majority of the parameters related to neutrinos have been determined by neutrino oscillation experiments with excellent precision. Experiments on neutrino oscillation and neutrino mixing have shown that neutrinos are massive. To fill in gaps, discrete symmetries are becoming more common alongside continuous symmetries while describing the observed pattern of neutrino mixing. Here, we present a $T_7$ flavor symmetry to explain the masses of charged leptons and neutrinos. The light neutrino mass matrix is derived using seesaw mechanism of type I, which involves the Dirac neutrino mass matrix as well as the right-handed neutrino mass matrix. We estimate the Pontecorvo-Maki-Nakagawa-Sakata matrix ($U_{PMNS}$), three mixing angles, ${\theta }_{12}$, ${\theta }_{23}$ and ${\theta }_{13}$, which are strongly correlated with the recent experimental results. The extent of $CP$ violation in neutrino oscillations is obtained by calculating Jarskog invariant $(J_{CP})$ on the behalf of $U_{PMNS}$. We also find the masses of three neutrinos and Effective Majorana neutrino mass parameter $⟨m_{ee}⟩$ which is $1.0960$ $meV$ and $10.9217$ $meV$ for normal and inverted hierarchy, respectively.

   hep-phPramana(2025)·0 citations
10. 10*

    Next-to-Leading-Order Weak Annihilation Correction to Rare $B\to \left\{K,\pi \right\}{\ell }^{+}{\ell }^{-}$ Decays

    Yong-Kang Huang🇨🇳 · Yue-Long Shen🇨🇳 · Chao Wang🇨🇳 · Yu-Ming Wang🇨🇳

    We accomplish for the first time the next-to-leading-order computation of the weak annihilation contribution to the exclusive electroweak penguin decays $B\to \left\{K,\pi \right\}{\ell }^{+}{\ell }^{-}$ with an energetic light-flavour meson, which is an essential missing piece of the complete QCD correction to the matrix elements of hadronic operators in the weak effective Hamiltonian. Both the hard functions and the jet functions in the perturbative factorization formulae from the short-distance fluctuations at the two distinct scales $m_b$ and $\sqrt{m_b\Lambda }$ are determined at $\mathcal{O}({\alpha }_s)$ with the soft-collinear factorization technique. We then demonstrate that the one-loop weak annihilation correction can bring about the noticeable impacts on theory predictions for the CP asymmetries and the isospin asymmetry in the $B\to \pi {\ell }^{+}{\ell }^{-}$ decays.

    hep-phhep-exhep-latPRL(2025)·13 citations
11. 11*

    Anomalous kaon correlations measured in Pb-Pb collisions at the LHC as evidence for the melting and refreezing of the QCD vacuum

    Joseph Kapusta🇺🇸 · Scott Pratt🇺🇸 · Mayank Singh🇺🇸

    Measurements of the dynamical correlations between neutral and charged kaons in central Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV by the ALICE Collaboration display anomalous behavior relative to conventional heavy-ion collision simulators. We consider other conventional statistical models, none of which can reproduce the magnitude and centrality dependence of the correlations. The data can be reproduced by coherent emission from domains which grow in number and volume with increasing centrality. We study the dynamical evolution of the strange quark condensate and show that the energy released during the expansion and cooling of the system may be sufficient to explain the anomaly.

    hep-phEPJ Web Conf.(2024)·0 citations
12. 12*

    Impact of local CP-odd domain in hot QCD on axionic domain-wall interpretation for NANOGrav 15-year Data

    Linlin Huang🇨🇳 · Yuanyuan Wang🇨🇳 · He-Xu Zhang🇨🇳 · Shinya Matsuzaki🇨🇳 · Hiroyuki Ishida🇯🇵 · Mamiya Kawaguchi🇨🇳 · Akio Tomiya🇯🇵

    We argue that the axionic domain-wall with a QCD bias may be incompatible with the NANOGrav 15-year data on a stochastic gravitational wave (GW) background, when the domain wall network collapses in the hot-QCD induced local CP-odd domain. This is due to the drastic suppression of the QCD bias set by the QCD topological susceptibility in the presence of the CP-odd domain with nonzero $\theta$ parameter of order one which the QCD sphaleron could generate. We quantify the effect on the GW signals by working on a low-energy effective model of Nambu-Jona-Lasinio type in the mean field approximation. We find that only at $\theta =\pi$, the QCD bias tends to get significantly large enough due to the criticality of the thermal CP restoration, which would, however, give too big signal strengths to be consistent with the NANOGrav 15-year data and would also be subject to the strength of the phase transition at the criticality.

    hep-phastro-ph.COPRD(2024)·7 citations
13. 13*

    Refitting cosmological data with neutrino mass and degeneracy

    Shek Yeung🇦🇿 · Wangzheng Zhang🇦🇿 · Ming-chung Chu🇨🇳

    A simple and natural extension of the standard Lambda cold dark matter ($\Lambda$CDM) model is to allow relic neutrinos to have finite chemical potentials. We confront this $\Lambda$CDM$\xi$ model, a $\Lambda$CDM with neutrino mass $M_{\nu }$ and degeneracy ${\xi }_3$ as additional parameters, with various cosmological data sets. We find that the $H_0$ and $S_8$ tensions become significant only in the presence of the cosmic microwave background (CMB) polarization data. Specifically, the global and local measurements agree to within 0.8$\sigma$ and 1.6$\sigma$ for the $H_0$ and $S_8$ tensions, respectively, when the CMB polarization data are not included. Therefore, the $H_0$ and $S_8$ tensions exist between CMB temperature and polarization data, both being global measurements. Fitting the $\Lambda$CDM$\xi$ model to the CMB temperature data, we find 3$\sigma$ evidence for nonzero neutrino mass ($M_{\nu }=0.57_{-0.13}^{+0.17}\mathrm{eV}$) and degeneracy (${\xi }_3=1.13_{-0.19}^{+0.41}$), and the O(1) neutrino degeneracy parameter is compatible with Big Bang nucleosynthesis data. The scalar index $n_s$ exceeds 1 slightly, which is compatible with some hybrid inflation models. Furthermore, the recent DESI baryon acoustic oscillation data prefer the $\Lambda$CDM$\xi$ model to the Planck $\Lambda$CDM model. Similar results are obtained when including additional supernova data, while the inclusion of the Atacama Cosmology Telescope $\tau$ prior shifts the preferred $M_{\nu }$ and ${\xi }_3$ values closer to zero and brings $n_s$ back to the values favored when the polarization data are included.

    hep-phastro-ph.COApJL(2025)·12 citations
14. 14*

    Giant CP violation in charmless three-body $B$ meson decays at LHCb: all order formalism for meson-meson final state interactions

    A. Reyes-Torrecilla🇪🇸 · J. R. Pelaez🇪🇸 · P. C. Magalhães🇧🇷

    LHCb has observed giant CP violation in localized regions of the Dalitz plots of B to three charmless light mesons. This has been interpreted as an enhancement due to strong two-body final state interactions. In this talk, we show how such interactions, described with dispersive analyses of data, can be implemented beyond the leading order expansion in the two-body re-scattering amplitude.

    hep-phActa Phys.Polon.Supp.(2024)·0 citations
15. 15*

    Nonlinear Pulse Dynamics in a Magnetized and Nonextensive Quark-Gluon Plasma

    Trambak Bhattacharyya🇵🇱 · Md Hasanujjaman🇮🇳

    We investigate the propagation of nonlinear energy density waves in a nonextensive quark-gluon plasma under the influence of a magnetic field using the reductive perturbation technique. For a nonextensive MIT bag equation of state, we obtain the governing equation for the first order perturbation of the energy density. We observe that an increase in the strength of the magnetic field results in the localization of the waves.

    hep-phhep-thnucl-th0 citations
16. 16*

    Gravitational Form Factors and Mechanical Properties of Quarks in Protons: A Basis Light-Front Quantization Approach

    Sreeraj Nair🇨🇳 · Chandan Mondal🇨🇳 · Siqi Xu🇨🇳 · Xingbo Zhao🇨🇳 · Asmita Mukherjee🇮🇳 · James P. Vary🇺🇸

    We compute the gravitational form factors (GFFs) and study their applications for the description of the mechanical properties such as the pressure, shear force distributions, and the mechanical radius of the proton from its light-front wave functions (LFWFs) based on basis light-front quantization (BLFQ). The LFWFs of the proton are given by the lowest eigenvector of a light-front effective Hamiltonian that incorporates a three-dimensional confining potential and a one-gluon exchange interaction with fixed coupling between the constituent quarks solved in the valence Fock sector. We find acceptable agreement between our BLFQ computations and the lattice QCD for the GFFs. Our $D$-term form factor also agrees well with the extracted data from the deeply virtual Compton scattering experiments at Jefferson Lab, and the results of different phenomenological models. The distributions of pressures and shear forces are similar to those from different models.

    hep-phPRD(2024)·31 citations
17. 17*

    Combination and Reinterpretation of LHC SUSY Searches

    Alexander Feike🇩🇪 · Juri Fiaschi🇬🇧 · Benjamin Fuks🇫🇷 · Michael Klasen🇩🇪 · Alexander Puck Neuwirth🇩🇪

    To maximise the information obtained from various independent new physics searches conducted at the LHC, it is imperative to consider the combination of multiple analyses. To showcase the exclusion power gained by combining signal regions from different searches, we consider a simplified scenario inspired by supersymmetry, with all particles but one squark flavour and a bino-like neutralino decoupled. The corresponding signal therefore comprises strong squark pair production, associated squark-neutralino production, as well as weak neutralino pair production. We find that considering the associated and strong production mechanisms together significantly impacts mass limits, while contributions from the weak production are insignificant in the context of current exclusion limits. In addition, we demonstrate that the combination of uncorrelated signal regions as assessed from the recent TACO approach substantially pushes exclusion limits towards higher masses, relative to the bounds derived from the most sensitive individual analyses.

    hep-phJHEP(2024)·6 citations
18. 18*

    Integrating Physics Inspired Features with Graph Convolution

    Rameswar Sahu🇮🇳

    With the advent of advanced machine learning techniques, boosted object tagging has witnessed significant progress. In this article, we take this field further by introducing novel architectural modifications compatible with a wide array of Graph Neural Network (GNN) architectures. Our approach advocates for integrating capsule layers, replacing the conventional decoding blocks in standard GNNs. These capsules are a group of neurons with vector activations. The orientation of these vectors represents important properties of the objects under study, with their magnitude characterizing whether the object under study belongs to the class represented by the capsule. Moreover, capsule networks incorporate a regularization by reconstruction mechanism, facilitating the seamless integration of expert-designed high-level features into the analysis. We have studied the usefulness of our architecture with the LorentzNet architecture for quark-gluon tagging. Here, we have replaced the decoding block of LorentzNet with a capsulated decoding block and have called the resulting architecture CapsLorentzNet. Our new architecture can enhance the performance of LorentzNet by 20 \% for the quark-gluon tagging task.

    hep-phcs.LGhep-exPRD(2025)·5 citations
19. 19*

    Collider imprint of vector-like leptons in light of anomalous magnetic moment and neutrino data

    Parham Dehghani🇨🇦 · Mariana Frank🇨🇦 · Benjamin Fuks🇫🇷

    We investigate the impact of incorporating vector-like leptons into the Standard Model, aiming to address longstanding puzzles related to the anomalous magnetic moments of the muon and electron while maintaining consistency with neutrino masses and mixings. We find that among the various representations of vector-like leptons permitted by the Standard Model gauge symmetry, only weak doublets and singlets offer satisfactory solutions, all associated with a significantly constrained parameter space. Our analysis delves into the associated parameter space, identifying representative benchmark scenarios suitable for collider studies. These setups yield a distinctive six-lepton signature whose associated signals can easily be distinguished from the Standard Model background, providing a clear signal indicative of new physics models featuring vector-like leptons. Our work hence sheds light on the potential implications of vector-like leptons in resolving discrepancies inherent to the Standard Model, while also offering insights into experimental avenues for further exploration.

    hep-phEPJC(2024)·3 citations
20. 20*

    Isotropization of a longitudinally expanding system of scalar fields in the 2PI formalism

    François Gelis🇫🇷 · Sigtryggur Hauksson🇫🇷

    Motivated by isotropization of QCD matter in the initial stages of heavy-ion collisions, we consider a system of scalar fields that undergoes a boost invariant longitudinal expansion. We use the framework of the two-particle irreducible (2PI) effective action, which is close to the underlying quantum field theory, and resum self-energy corrections up to three loops. The resulting 2PI equations of motion are expressed in terms of the Milne coordinates to account for longitudinal expansion. By solving numerically these equations of motion, we can extract the occupation density and the effective mass generated by in-medium interactions. At the largest values of the coupling considered in this study, we observe the onset of isotropization both in the occupation number and in the momentum dependence of the effective mass.

    hep-phnucl-thJHEP(2024)·5 citations
21. 21*

    Image and Point-cloud Classification for Jet Analysis in High-Energy Physics: A survey

    Hamza Kheddar🇩🇿 · Yassine Himeur🇮🇳 · Abbes Amira🇦🇪 · Rachik Soualah🇦🇪

    Nowadays, there has been a growing trend in the field of high-energy physics (HEP), in both its experimental and phenomenological studies, to incorporate machine learning (ML) and its specialized branch, deep learning (DL). This review paper provides a thorough illustration of these applications using different ML and DL approaches. The first part of the paper examines the basics of various particle physics types and establishes guidelines for assessing particle physics alongside the available learning models. Next, a detailed classification is provided for representing Jets that are reconstructed in high-energy collisions, mainly in proton-proton collisions at well-defined beam energies. This section covers various datasets, preprocessing techniques, and feature extraction and selection methods. The presented techniques can be applied to future hadron-hadron colliders (HHC), such as the high-luminosity LHC (HL-LHC) and the future circular collider - hadron-hadron (FCChh). The authors then explore several AI techniques analyses designed specifically for both image and point-cloud (PC) data in HEP. Additionally, a closer look is taken at the classification associated with Jet tagging in hadron collisions. In this review, various state-of-the-art (SOTA) techniques in ML and DL are examined, with a focus on their implications for HEP demands. More precisely, this discussion addresses various applications in extensive detail, such as Jet tagging, Jet tracking, particle classification, and more. The review concludes with an analysis of the current state of HEP using DL methodologies. It highlights the challenges and potential areas for future research, which are illustrated for each application.

    hep-phcs.AIcs.CVeess.IV+1Front.Phys.(Beijing)(2025)·7 citations
22. 22*

    Strongly-ordered infrared counterterms from factorisation

    Lorenzo Magnea🇮🇹 · Calum Milloy🇮🇹 · Chiara Signorile-Signorile🇩🇪 · Paolo Torrielli🇮🇹

    In the context of infrared subtraction algorithms beyond next-to-leading order, it becomes necessary to consider multiple infrared limits of scattering amplitudes, in which several particles become soft or collinear in a strongly-ordered sequence. We study these limits from the point of view of infrared factorisation, and we provide general definitions of strongly-ordered soft and collinear kernels in terms of gauge-invariant operator matrix elements. With these definitions in hand, it is possible to construct local subtraction counterterms for strongly-ordered configurations. Because of their factorised structure, these counterterms cancel infrared poles of real-virtual contributions by construction. We test these ideas at tree level for multiple emissions, and at one loop for single and double emissions, contributing to NNLO and N3LO distributions, respectively.

    hep-phJHEP(2024)·15 citations
23. 23*

    Holographic Energy Correlators for Confining Theories

    Csaba Csáki🇺🇸 · Ameen Ismail🇺🇸

    We present a holographic calculation of energy correlators in a simple model of confinement based on a warped extra dimension with an IR brane. For small distances we reproduce the constant correlators of a strongly-coupled conformal field theory, while for large distances the effects of confinement dominate and the correlators decay exponentially. We find exact shockwave solutions to the Einstein equations in the presence of the IR brane, hence avoiding the need for a perturbative expansion in terms of Witten diagrams. While some of the expected qualitative features of energy correlators in quantum chromodynamics (QCD) are reproduced, our crude model of confinement does not capture the effects of asymptotic freedom nor exhibit jetty behavior. We expect that our method can also be applied to more realistic models of confinement incorporating asymptotic freedom, which should fix some of the deviations from QCD.

    hep-phhep-thJHEP(2024)·17 citations
24. 24*

    ALP contribution to the Strong CP problem

    Victor Enguita🇪🇸 · Belen Gavela🇪🇸 · Benjamin Grinstein🇺🇸 · Pablo Quilez🇺🇸

    We compute the one-loop contribution to the $\bar{\theta }$-parameter of an axion-like particle (ALP) with CP-odd derivative couplings. Its contribution to the neutron electric dipole moment is shown to be orders of magnitude larger than that stemming from the one-loop ALP contributions to the up- and down-quark electric and chromoelectric dipole moments. This strongly improves existing bounds on ALP-fermion CP-odd interactions, and also sets limits on previously unconstrained couplings. The case of a general singlet scalar is analyzed as well. In addition, we explore how the bounds are modified in the presence of a Peccei-Quinn symmetry.

    hep-phPRD(2024)·4 citations
25. 25*

    Mixed Species Charge and Baryon Balance Functions Studies with PYTHIA

    Claude Pruneau🇺🇸 · Sumit Basu🇸🇪 · Victor Gonzalez🇺🇸 · Brian Hanley🇺🇸 · Ana Marin🇩🇪 · Alexandru F. Dobrin🇷🇴 · Alexandru Manea🇷🇴

    Mixed species charge and baryon balance functions are computed based on proton--proton (pp) collisions simulated with the PYTHIA8 model. Simulations are performed with selected values of the collision energy $\sqrt{s}$ and the Monash tune and the Ropes and Shoving modes of PYTHIA8 to explore whether such measurements provide useful new information and constraints on mechanisms of particle production in pp collisions. Charge balance functions are studied based on mixed pairs of pions, kaons, and protons, whereas baryon balance functions are computed for mixed low mass strange and non-strange baryons. Both charge and baryon balance functions of mixed particle pairs feature shapes and amplitudes that sensitively depend on the particle considered owing largely to the particle production mechanisms implemented in PYTHIA. The evolution of balance functions integrals with the longitudinal width of the acceptance are presented and one finds that sums of such integrals for a given reference particle obey expected sum rules for both charge and baryon balance functions. Additionally, both types of balance functions are found to evolve in shape and amplitude with increasing collision energy $\sqrt{s}$ and the PYTHIA tunes considered.

    hep-phhep-exnucl-exnucl-thPRC(2024)·4 citations
26. 26*

    Anatomy of Vector-Like Bottom-Quark Models in the Alignment Limit of the 2-Higgs Doublet Model Type-II

    Abdesslam Arhrib (1)🇲🇦 · Rachid Benbrik (2)🇲🇦 · Mohammed Boukidi (2)🇲🇦 · Stefano Moretti (3) (4) ((1) Abdelmalek Essaadi University, Faculty of Sciences and Techniques, Tangier, Morocco, (2) Polydisciplinary Faculty, Laboratory of Fundamental and Applied Physics, Cadi Ayyad University, Sidi Bouzid, Safi, Morocco, (3) School of Physics and Astronomy, University of Southampton, United Kingdom, (4) Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden)🇬🇧

    Expanding upon our ongoing investigation of Vector-Like Quark (VLQ) phenomenology within a 2-Higgs Doublet Model (2HDM) framework, in this paper, we complement a previous one dedicated to Vector-Like Top-quarks (VLTs) by studying Vector-Like Bottom-quarks (VLBs), specifically focusing on their behavior in the alignment limit of a Type-II Yukawa structure. We examine the potential for detecting VLBs at the Large Hadron Collider (LHC) and analyze their decay signatures, encompassing both Standard Model (SM) processes and exotic decays. The objective is to differentiate among singlet, doublet, and triplet configurations of VLBs by identifying distinct decay patterns, thereby providing insights into the structure of Beyond the SM (BSM) physics.

    hep-phEPJC(2024)·19 citations
27. 27*

    Simulations of stochastic fluid dynamics near a critical point in the phase diagram

    Chandrodoy Chattopadhyay🇺🇸 · Josh Ott🇺🇸 · Thomas Schaefer🇺🇸 · Vladimir V. Skokov🇺🇸

    We present simulations of stochastic fluid dynamics in the vicinity of a critical endpoint belonging to the universality class of the Ising model. This study is motivated by the challenge of modeling the dynamics of critical fluctuations near a conjectured critical endpoint in the phase diagram of Quantum Chromodynamics (QCD). We focus on the interaction of shear modes with a conserved scalar density, which is known as model H. We show that the observed dynamical scaling behavior depends on the correlation length and the shear viscosity of the fluid. As the correlation length is increased or the viscosity is decreased we observe a cross-over from the dynamical exponent of critical diffusion, $z\simeq 4$, to the expected scaling exponent of model H, $z\simeq 3$. We use our method to investigate time-dependent correlation function of non-Gaussian moments $M^n(t)$ of the order parameter. We find that the relaxation time depends in non-trivial manner on the power $n$.

    ↳ nucl-thhep-phphysics.flu-dynPRL(2024)·29 citations
28. 28*

    Two-dimensional gauge anomalies and $p$-adic numbers

    Imogen Camp🇬🇧 · Ben Gripaios🇬🇧 · Khoi Le Nguyen Nguyen🇬🇧

    We show how methods of number theory can be used to study anomalies in gauge quantum field theories in spacetime dimension two. To wit, the anomaly cancellation conditions for the abelian part of the local anomaly admit solutions if and only if they admit solutions in the reals and in the $p$-adics for every prime $p$ and we use this to build an algorithm to find all solutions.

    ↳ hep-thhep-phJHEP(2024)·3 citations
29. 29*

    Simulating quantum field theories on continuous-variable quantum computers

    Steven Abel🇬🇧 · Michael Spannowsky🇬🇧 · Simon Williams🇬🇧

    We delve into the use of photonic quantum computing to simulate quantum mechanics and extend its application towards quantum field theory. We develop and prove a method that leverages this form of Continuous-Variable Quantum Computing (CVQC) to reproduce the time evolution of quantum-mechanical states under arbitrary Hamiltonians, and we demonstrate the method's remarkable efficacy with various potentials. Our method centres on constructing an evolver-state, a specially prepared quantum state that induces the desired time-evolution on the target state. This is achieved by introducing a non-Gaussian operation using a measurement-based quantum computing approach, enhanced by machine learning. Furthermore, we propose a framework in which these methods can be extended to encode field theories in CVQC without discretising the field values, thus preserving the continuous nature of the fields. This opens new avenues for quantum computing applications in quantum field theory.

    ↳ quant-phhep-phhep-thPRA(2024)·32 citations
30. 30*

    Gauge Theory Bootstrap: Pion amplitudes and low energy parameters

    Yifei He🇫🇷 · Martin Kruczenski🇺🇸

    Following the Gauge Theory Bootstrap method proposed in our previous work [arXiv:2309.12402], we compute pion scattering phase shifts for all partial waves with angular momentum $\ell \le 3$ up to 2 GeV and calculate the low energy $\chi$PT coefficients ${\bar{\ell }}_{1,2,4,6}$. The method looks for the most general S-matrix that matches at low energy the tree level amplitudes of the non-linear sigma model and at high energy, QCD sum rules and form factors. This is a theoretical/numerical calculation that uses as only data the pion mass $m_{\pi }$, pion decay constant $f_{\pi }$ and the QCD parameters $N_c=3$, $N_f=2$, $m_q$ and ${\alpha }_s$. All results are in reasonable agreement with experiment. In particular, we find the $\rho (770)$, $f_2(1270)$ and $\rho (1450)$ resonances. The interplay between the UV gauge theory and low energy pion physics is an example of a general situation where we know the microscopic theory as well as the effective theory of long wavelength fluctuations but we want to solve the strongly coupled dynamics at intermediate energies. The bootstrap builds a bridge between the low and high energy by determining the consistent S-matrix that matches both and provides, in this case, a new direction to understand the strongly coupled physics of gauge theories.

    ↳ hep-thhep-lathep-ph24 citations
31. 31*

    Mode Recombination Formula and Nonanalytic Term in Effective Potential at Finite Temperature on Compactified Space

    Makoto Sakamoto🇯🇵 · Kazunori Takenaga🇯🇵

    We develop a new formula called a mode recombination formula, and we can recast the effective potential at finite temperature in one-loop approximation for fermion and scalar fields on the $D$-dimensional spacetime, $S_{\tau }^1\times R^{D-(p+1)}\times {\prod }_{i=1}^p{S}_i^1$ into a convenient form for discussing nonanalytic terms, which cannot be written in the form of any positive integer power of the field-dependent mass squared, in the effective potential. The formula holds irrespective of whether the field is a fermion or a scalar and of boundary conditions for spatial $S_i^1$ directions and clarifies the importance of zero modes in the Matsubara and Kaluza-Klein modes for the existence of the nonanalytic terms. The effective potential is drastically simplified further to obtain the nonanalytic terms in easier and more transparent way. In addition to reproducing previous results, we find that there exists no nonanalytic term for the fermion field with arbitrary boundary condition for the spatial $S_i^1$ direction, which is also the case for the scalar field with the antiperiodic boundary condition for the spatial direction.

    ↳ hep-thhep-phPRD(2024)·1 citation
32. 32*

    Test of lepton universality and measurement of the form factors of $D^0\to K^{\ast }(892{)}^{-}{\mu }^{+}{\nu }_{\mu }$

    BESIII Collaboration: M. Ablikim · M. N. Achasov · P. Adlarson · O. Afedulidis · X. C. Ai · R. Aliberti · A. Amoroso · Q. An · Y. Bai · O. Bakina · I. Balossino · Y. Ban and 649 other authors

    We report a first study of the semileptonic decay $D^0\to K^{-}{\pi }^0{\mu }^{+}{\nu }_{\mu }$ by analyzing an $e^{+}{e}^{-}$ annihilation data sample of $7.9{\mathrm{fb}}^{-1}$ collected at the center-of-mass energy of 3.773 GeV with the BESIII detector. The absolute branching fraction of $D^0\to K^{-}{\pi }^0{\mu }^{+}{\nu }_{\mu }$ is measured for the first time to be $(0.729\pm 0.014_{\mathrm{stat}}\pm 0.011_{\mathrm{syst}})\%$. Based on an amplitude analysis, the $S\text{-}\mathrm{wave}$ contribution is determined to be $(5.76\pm 0.35_{\mathrm{stat}}\pm 0.29_{\mathrm{syst}})\%$ of the total decay rate in addition to the dominated $K^{\ast }(892{)}^{-}$ component. The branching fraction of $D^0\to K^{\ast }(892{)}^{-}{\mu }^{+}{\nu }_{\mu }$ is given to be $(2.062\pm 0.039_{\mathrm{stat}}\pm 0.032_{\mathrm{syst}})\%$, which improves the precision of the world average by a factor of 5. Combining with the world average of $\mathcal{B}(D^0\to K^{\ast }(892{)}^{-}{e}^{+}{\nu }_e)$, the ratio of the branching fractions obtained is $\frac{\mathcal{B}(D^0\to K^{\ast }(892{)}^{-}{\mu }^{+}{\nu }_{\mu })}{\mathcal{B}(D^0\to K^{\ast }(892{)}^{-}{e}^{+}{\nu }_e)}=0.96\pm 0.08$, in agreement with lepton flavor universality. Furthermore, assuming single-pole dominance parameterization, the most precise hadronic form factor ratios for $D^0\to K^{\ast }(892{)}^{-}{\mu }^{+}{\nu }_{\mu }$ are extracted to be $r_V=V(0)/A_1(0)=1.37\pm 0.09_{\mathrm{stat}}\pm 0.03_{\mathrm{syst}}$ and $r_2=A_2(0)/A_1(0)=0.76\pm 0.06_{\mathrm{stat}}\pm 0.02_{\mathrm{syst}}$.

    ↳ hep-exhep-phPRL(2025)·17 citations
33. 33*

    Force metrology with plane parallel plates: Final design review and outlook

    Hamid Haghmoradi🇦🇹 · Hauke Fischer🇦🇹 · Alessandro Bertolini🇳🇱 · Ivica Galić🇦🇹 · Francesco Intravaia🇩🇪 · Mario Pitschmann🇦🇹 · Raphael Schimpl🇦🇹 · René I.P. Sedmik🇦🇹

    During the past few decades, abundant evidence for physics beyond the two standard models of particle physics and cosmology was found. Yet, we are tapping into the dark regarding our understanding of the dark sector. For more than a century, open problems related to the nature of the vacuum remain unresolved. Besides the traditional high-energy frontier and cosmology, technological advancement provides complementary access to new physics via high-precision experiments. Among the latter, the Casimir And Non-Newtonian force EXperiment (\cannex{}) has successfully completed its proof-of-principle phase and will soon commence operation. Benefiting from its plane parallel plate geometry, both interfacial and gravity-like forces are maximized, leading to increased sensitivity. A wide range of dark sector forces, Casimir forces in and out of thermal equilibrium, and gravity will be tested. This article describes the final experimental design, its sensitivity, and expected results.

    ↳ hep-exastro-ph.COgr-qchep-ph+1MDPI Physics(2024)·7 citations
34. 34*

    Probing multi-particle bunching from intermittency analysis in relativistic heavy-ion collisions

    Valeria Zelina Reyna Ortiz🇵🇱 · Maciej Rybczynski🇵🇱 · Zbigniew Wlodarczyk🇵🇱

    It has been demonstrated that factorial moments analysis in dependence from the size of phase-space cells (when the latter is decreased but is still considerably large), exhibits sensitivity to particle bunching within a system situated in the two-dimensional cell. Based on recent findings concerning fluctuations in charge particle density observed in central Au + Au collisions at various energies ranging from $\sqrt{s_{NN}}$ = 7.7 to 200 GeV at RHIC/STAR, it is proposed that analyzing factorial moments in relativistic heavy-ion collisions could serve as a method to investigate density fluctuations linked to correlation phenomena. Our understanding of particle production mechanisms may be enriched by using factorial moments analysis to gain new information contained in them that was previously unavailable.

    ↳ nucl-thhep-phNPA(2025)·1 citation
35. 35*

    Tidal Formation of dark matter deficit diffuse galaxy NGC1052-DF2 by SIDM

    Zhao-Chen Zhang🇨🇳 · Xiao-Jun Bi🇨🇳 · Peng-Fei Yin🇨🇳

    Observations have revealed a significant dark matter deficit in the ultra-diffuse galaxy NGC1052-DF2 (DF2). It is widely accepted that the formation of this unique galaxy can be attributed to the tidal stripping of its host galaxy, NGC1052. In this study, we simulate the evolution of a satellite system containing globular clusters (GCs) within an accreting host halo in the framework of self-interacting dark matter (SIDM). Our simulation results suggest that the heightened tidal stripping resulting from DM self-interactions can give rise to the transformation of a conventional dwarf galaxy into a dark matter deficit galaxy resembling DF2. By comparing the simulation results with identical initial conditions in both the standard cold dark matter (CDM) and SIDM models, we find that the latter is more likely to replicate the properties of DF2. Furthermore, we demonstrate that a DF2 analog can also be produced on an orbit with a greater pericenter distance by increasing the strength of DM self-interactions. This suggests that the issue of extreme orbital parameters can be mitigated by implementing the SIDM model. The distributions of the GC population derived in our SIDM simulation are consistent with the observed characteristics of DF2. For comparison, we also explored the potential for achieving GC distributions in the context of CDM.

    ↳ astro-ph.COhep-phApJ(2025)·8 citations
36. 36*

    Connecting 2-Forms, Conformal Transformations, Curvature Invariants and Topological Classes in Einstein Spacetimes

    Jack C. M. Hughes🇦🇪 · Fedor V. Kusmartsev🇦🇪

    The unique Nature of the Lorentz group in four dimensions is the root cause of the many remarkable properties of the Einstein spacetimes, in particular their operational structure on the 2-forms. We show how this operational structure can be used for two ends. First, it allows for a simple generalization of the Birkhoff theorem to Schwarzschild (A)de-Sitter spacetime. Second, it provides the means to construct an Abelian endomorphism group on the space of 2-forms. It is observed that taking the trace over this group element-wise induces a further Abelian group which may be identified with a tensor representation of conformal transformations, giving Einstein spacetimes access to their own conformal equivalence class. A further trace over the group yields the curvature invariants of the spacetime. The Kretschmann scalar becomes the topological Euler density, which may be linked in a simple way to the Hawking temperature of horizons.

    ↳ gr-qchep-phhep-thmath-ph+14 citations
37. 37*

    Detecting superfluid transition in the pulsar core

    Partha Bagchi (1) · Biswanath Layek (2) · Dheeraj Saini (3) · Anjishnu Sarkar (3) · Ajit M. Srivastava (4) · Deepthi Godaba Venkata (2) ((1) School of Physical Sciences, National Institute of Science Education and Research, Bhubaneswar, India, (2) Department of Physics, Birla Institute of Technology and Science, Pilani-333031, India, (3) Physics Department, The LNM Institute of Information Technology, Jaipur-302031, India, (4) Institute of Physics, Sachivalaya Marg, Bhubaneswar-751005, India)

    It is believed that the core of a neutron star can be host to various novel phases of matter, from nucleon superfluid phase to exotic high baryon density quantum chromodynamics (QCD) phases. Different observational signals for such phase transitions have been discussed in the literature. Here, we point out a unique phenomenon associated with phase transition to a superfluid phase, which may be the nucleon superfluid phase or a phase like the CFL phase, allowing for superfluid vortices. In any superfluid phase transition, a random network of vortices forms via the so-called Kibble-Zurek mechanism, which eventually mostly decays away, finally leaving primarily vortices arising from the initial angular momentum of the core. This transient, random vortex network can have a non-zero net angular momentum for the superfluid component, which will generally be oriented in an arbitrary direction. This is in contrast to the final vortices, which arise from initial rotation and hence have the initial angular momentum of the neutron star. The angular momentum of the random vortex network is balanced by an equal and opposite angular momentum in the normal fluid due to the conservation of angular momentum, thereby imparting an arbitrarily oriented angular momentum component to the outer shell of the neutron star. This will affect the pulse timing and pulse profile of a pulsar. These changes in the pulses will decay away in a characteristic manner such that the random vortex network decays, obeying specific scaling laws leading to universal features for the detection of superfluid transitions occurring in a pulsar core.

    ↳ astro-ph.HEhep-phnucl-thMNRAS(2024)·2 citations
38. 38*

    Rare Charm Decays at BESIII

    Zhijun Li🇨🇳 · Zhengyun You🇨🇳

    The rare and forbidden processes within the Standard Model offer an opportunity to explore potential new physics beyond the SM. We summarize the research method and the recent results of rare charm decays at BESIII based on the extensive data samples in the $\tau -c$ energy region, many of which impose stringent constraints on the new physics.

    ↳ hep-exhep-ph11 citations
39. 39*

    On the weak and strong field effects in antiscalar background

    Eduard Mychelkin🇰🇿 · Maxim Makukov🇰🇿 · Gulnara Suliyeva🇰🇿 · Nosratollah Jafari🇰🇿

    The triumph of general relativity under the banner "gravity is geometry" began with confirming the crucial effects within the Solar system and proceeded recently to the strong-field shadow effect for the compact object in the center of the Milky Way. Here, we examine some of those phenomena for the Einstein-scalar equations in the antiscalar regime to reveal the difference from vacuum both in weak and strong fields. As a result, we find that for week-field perihelion shift the difference between vacuum and antiscalar cases proves to be observationally imperceptible in practice, even for S-cluster stars with high eccentricities, and even if accumulated over a century. In strong-field case, we reconsider the shadow effect (this time without involving complex-valued scalar field) as the most perspective from an observational viewpoint. Even though the resulting difference is quite appreciable (about 5%), no conclusion can be made until the mass of the central object is known with the accuracy an order of magnitude higher than the currently available.

    ↳ gr-qchep-phGen.Rel.Grav.(2024)·3 citations
40. 40*

    Lattice QCD estimates of thermal photon production from the QGP

    Sajid Ali🇩🇪 · Dibyendu Bala🇩🇪 · Anthony Francis🇹🇼 · Greg Jackson🇫🇷 · Olaf Kaczmarek🇩🇪 · Jonas Turnwald🇩🇪 · Tristan Ueding🇩🇪 · Nicolas Wink🇩🇪

    Thermal photons produced in heavy-ion collision experiments are an important observable for understanding quark-gluon plasma (QGP). The thermal photon rate from the QGP at a given temperature can be calculated from the spectral function of the vector current correlator. Extraction of the spectral function from the lattice correlator is known to be an ill-conditioned problem, as there is no unique solution for a spectral function for a given lattice correlator with statistical errors. The vector current correlator, on the other hand, receives a large ultraviolet contribution from the vacuum, which makes the extraction of the thermal photon rate difficult from this channel. We therefore consider the difference between the transverse and longitudinal part of the spectral function, only capturing the thermal contribution to the current correlator, simplifying the reconstruction significantly. The lattice correlator is calculated for light quarks in quenched QCD at $T=470$MeV ($\sim 1.5T_c$), as well as in 2+1 flavor QCD at $T=220$MeV ($\sim 1.2T_{pc}$) with $m_{\pi }=320$ MeV. In order to quantify the non-perturbative effects, the lattice correlator is compared with the corresponding $\text{NLO}+{\text{LPM}}^{\text{LO}}$ estimate of correlator. The reconstruction of the spectral function is performed in several different frameworks, ranging from physics-informed models of the spectral function to more general models in the Backus-Gilbert method and Gaussian Process regression. We find that the resulting photon rates agree within errors.

    ↳ hep-lathep-phPRD(2024)·19 citations
41. 41*

    Finite nuclear mass correction to the hyperfine splitting in hydrogenic systems

    Krzysztof Pachucki🇵🇱

    A general quantum electrodynamic method for derivation of nuclear recoil corrections in hydrogenic systems, which are exact in the nuclear charge parameter $Z\alpha$, is introduced. The exemplary derivation is presented for the $O(m/M)$ nuclear pure recoil correction to the hyperfine splitting. The obtained result is verified by comparison to the known $(Z\alpha {)}^5$ contribution

    ↳ physics.atom-phhep-phPRA(2024)·3 citations
42. 42*

    Precise measurement of the cosmic-ray spectrum and $⟨\ln A⟩$ by LHAASO -- connecting the Galactic to the extragalactic components

    Xing-Jian Lv🇨🇳 · Xiao-Jun Bi🇨🇳 · Kun Fang🇨🇳 · Yi-Qing Guo🇨🇳 · Hui-Hai He🇨🇳 · Ling-Ling Ma🇨🇳 · Peng-Fei Yin🇨🇳 · Qiang Yuan🇨🇳 · Meng-Jie Zhao🇨🇳

    Recently LHAASO Collaboration gives precise measurements of cosmic rays (CR) all particle energy spectrum and mean logarithmic mass $⟨\ln A⟩$ from 0.3 PeV to 30 PeV. Combining the CR measurements by AMS-02 and DAMPE in space and that by LHAASO and Auger on the ground we construct a model to recover all these measurements from tens of GeV to tens of EeV. We find the LHAASO measurement is crucial in the model construction by connecting the Galactic component to the extragalactic component. The precise measurements of CR spectra for individual species by AMS-02 and DAMPE together with the newest LHAASO results clearly indicates three Galactic CR components, that is, a soft low energy background, a hard high energy component, and a local source contribution. However, the LHAASO data show that above $\sim 10^{16}$ eV a nonnegligible extragalactic component must be included. Combining the Auger results and the LHAASO results we figure out the extragalactic CRs which need at least two components at lower and higher energies. Thanks to the precise measurements by LHAASO the constraints on the model parameters are quite stringent. The spectra features and mass measurements in all energy range are all well reproduced in the model.

    ↳ astro-ph.HEhep-phApJ(2025)·18 citations
43. 43*

    Form factor for Dalitz decays from $J/\psi$ to light pseudoscalars

    Chunjiang Shi🇨🇳 · Ying Chen🇨🇳 · Xiangyu Jiang🇨🇳 · Ming Gong🇨🇳 · Zhaofeng Liu🇨🇳 · Wei Sun🇨🇳

    We calculate the form factor $M(q^2)$ for the Dalitz decay $J/\psi \to {\gamma }^{\ast }(q^2){\eta }_{(N_f=1)}$ with ${\eta }_{(N_f)}$ being the SU($N_f$) flavor singlet pseudoscalar meson. The difference among the partial widths $\Gamma (J/\psi \to \gamma {\eta }_{(N_f)})$ at different $N_f$ can be attributed in part to the ${\mathbf{U}}_A(1)$ anomaly that induces a $N_f$ scaling. $M(q^2)$'s in $N_f=1,2$ are both well described by the single pole model $M(q^2)=M(0)/(1-q^2/{\Lambda }^2)$. Combined with the known experimental results of the Dalitz decays $J/\psi \to P{e}^{+}{e}^{-}$, the pseudoscalar mass $m_P$ dependence of the pole parameter $\Lambda$ is approximated by $\Lambda (m_P^2)={\Lambda }_1(1-m_P^2/{\Lambda }_2^2)$ with ${\Lambda }_1=2.64(4)\mathrm{GeV}$ and ${\Lambda }_2=2.97(33)\mathrm{GeV}$. These results provide inputs for future theoretical and experimental studies on the Dalitz decays $J/\psi \to P{e}^{+}{e}^{-}$.

    ↳ hep-lathep-exhep-phCPC(2024)·7 citations
44. 44*

    Revisiting the effect of lens mass models in cosmological applications of strong gravitational lensing

    Christopher Harvey-Hawes🇳🇿 · David L. Wiltshire🇳🇿

    Strong gravitational lens system catalogues are typically used to constrain a combination of cosmological and empirical power-law lens mass model parameters, often introducing additional empirical parameters and constraints from high resolution imagery. We investigate these lens models using Bayesian methods through a novel alternative that treats spatial curvature via the non-FLRW timescape cosmology. We apply Markov Chain Monte Carlo methods using the catalogue of 161 lens systems of Chen et al (arXiv:1809.09845) in order to constrain both lens and cosmological parameters for: (i) the standard $\Lambda$CDM model with zero spatial curvature; and (ii) the timescape model. We then generate large mock data sets to further investigate the choice of cosmology on fitting simple power-law lens models. In agreement with previous results, we find that in combination with single isothermal sphere parameters, models with zero FLRW spatial curvature fit better as the free parameter approaches an unphysical empty universe, ${\Omega }_{\mathrm{M}0}\to 0$. By contrast, the timescape cosmology is found to prefer parameter values in which its cosmological parameter, the present void fraction, is driven to $f_{\mathrm{v}0}\to 0.73$ and closely matches values that best fit independent cosmological data sets: supernovae Ia distances and the cosmic microwave background. This conclusion holds for a large range of seed values $f_{\mathrm{v}0}\in \{0.1,0.9\}$, and for timescape fits to both timescape and FLRW mocks. Regardless of cosmology, unphysical estimates of the distance ratios given from power-law lens models result in poor goodness of fit. With larger datasets soon available, separation of cosmology and lens models must be addressed.

    ↳ astro-ph.COastro-ph.GAgr-qchep-phMNRAS(2024)·4 citations
45. 45*

    Soft Scalars in Effective Field Theory

    Maria Derda🇺🇸 · Andreas Helset🇨🇭 · Julio Parra-Martinez🇨🇦

    We derive a soft theorem for a massless scalar in an effective field theory with generic field content using the geometry of field space. This result extends the geometric soft theorem for scalar effective field theories by allowing the massless scalar to couple to other scalars, fermions, and gauge bosons. The soft theorem keeps its geometric form, but where the field-space geometry now involves the full field content of the theory. As a bonus, we also present novel double soft theorems with fermions, which mimic the geometric structure of the double soft theorem for scalars.

    ↳ hep-thhep-phJHEP(2024)·29 citations
46. 46*

    Many body gravity and the galaxy rotation curves

    S Ganesh🇺🇸

    A novel theory was proposed earlier to model systems with thermal gradients, based on the postulate that the spatial and temporal variation in temperature can be recast as a variation in the metric. Combining the variation in the metric due to the thermal variations and gravity, leads to the concept of thermal gravity in a 5-D space-time-temperature setting. When the 5-D Einstein field equations are projected to a 4-D space, they result in additional terms in the field equations. This may lead to unique phenomena such as the spontaneous symmetry breaking of scalar particles in the presence of a strong gravitational field. This theory, originally conceived in a quantum mechanical framework, is now adapted to explain the galaxy rotation curves. A galaxy is not in a state of thermal equilibrium. A parameter called the "degree of thermalization" is introduced to model partially thermalized systems. The generalization of thermal gravity to partially thermalized systems, leads to the theory of many-body gravity. The theory of many-body gravity is now shown to be able to explain the rotation curves of the Milky Way and the M31 (Andromeda) galaxies, to a fair extent. The radial acceleration relation (RAR) for 63 galaxies, with their galactic masses spanning three orders of magnitude, has been replicated. Finally, the wide binary star (WBS) system is touched upon.

    ↳ gr-qcastro-ph.GAhep-phhep-th+2EPJC(2024)·2 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.