Tue·Jul 2, 2024Tuesday·July 2, 2024

1. 01*

   $W-$mass and Muon $g-2$ in Inert 2HDM Extended by Singlet Complex Scalar

   Hrishabh Bharadwaj🇮🇳 · Mamta Dahiya🇮🇳 · Sukanta Dutta🇮🇳 · Ashok Goyal🇮🇳

   The deviations of the recent measurements of the muon magnetic moment and the $W-$boson mass from their SM predictions hint to new physics beyond the SM. In this article, we address the observed discrepancies in the $W$-boson mass and muon anomalous magnetic moment in the Inert Two Higgs Doublet Model (I2HDM) extended by a complex scalar field singlet under the SM gauge group. The model is constrained from the existing LEP data and the measurements of partial decay widths to gauge bosons at LHC. It is shown that a large subset of this constrained parameter space of the model can simultaneously accommodate the $W$-boson mass and also explain the muon $g-2$ anomaly.

   hep-phPRD(2024)·4 citations
2. 02*

   Top-philic Machine Learning

   Rahool Kumar Barman🇯🇵 · Sumit Biswas🇺🇸

   In this article, we review the application of modern machine-learning (ML) techniques to boost the search for processes involving the top quarks at the LHC. We revisit the formalism of Convolutional Neural Networks (CNNs), Graph Neural Networks (GNNs), and Attention Mechanisms. Based on recent studies, we explore their applications in designing improved top taggers, top reconstruction, and event classification tasks. We also examine the ML-based likelihood-free inference approach and generative unfolding models, focusing on their applications to scenarios involving top quarks.

   hep-phhep-exEur.Phys.J.ST(2024)·3 citations
3. 03*

   High-Temperature QCD Static Potential beyond Leading Order

   Margaret E. Carrington🇨🇦 · Cristina Manuel🇪🇸 · Joan Soto🇪🇸

   We calculate the leading and next-to-leading corrections to the real-time QCD static potential in a high temperature medium in the region where bound states transit from narrow resonances to wide ones. We find sizable contributions to both the real and the imaginary part of the potential. The calculation involves both loop diagrams calculated in the Hard Thermal Loop (HTL) effective theory and power corrections to the HTL Lagrangian calculated in QCD. We compare our results with recent lattice data.

   hep-phhep-thPRL(2025)·4 citations
4. 04*

   Study of semileptonic $B\to DP{\ell }^{+}{\nu }_{\ell }$ decays based on the SU(3) flavor symmetry

   Ru-Min Wang🇨🇳 · Yi-Jie Zhang🇨🇳 · Meng-Yuan Wan🇨🇳 · Xiao-Dong Cheng🇨🇳 · Yuan-Guo Xu🇨🇳

   Decays $B\to DP{\ell }^{+}{\nu }_{\ell }(\ell =e,\mu ,\tau )$ with the non-resonance, the charmed vector resonances, the charmed scalar resonances and the charmed tensor resonances are calculated by using the SU(3) flavor symmetry. Firstly, the decay amplitudes of different modes are related by the SU(3) flavor symmetry. Then, relevant experiential data are used to constrain nonperturbative coefficients in the non-resonant and various resonant $B\to DP{\ell }^{+}{\nu }_{\ell }$ decays. Finally, using the constrained nonperturbative coefficients, the branching ratios of not-yet-measured $B\to D^{\ast }P{\ell }^{+}{\nu }_{\ell }$ decays with the non-resonant and various charmed resonant contributions are predicted. Many branching ratios are predicted for the first time. We find that $B\to D{\eta }^{\prime }{\ell }^{+}{\nu }_{\ell },B_s\to D_s{\eta }^{\prime }{\ell }^{+}{\nu }_{\ell }$ decays only receive the non-resonant contributions, $B\to D_{s}K{\ell }^{+}{\nu }_{\ell }$, $B_s\to DK{\ell }^{+}{\nu }_{\ell }$, $B\to D\eta {\ell }^{+}{\nu }_{\ell }$ and $B_s\to D_s\eta {\ell }^{+}{\nu }_{\ell }$ decays receive both non-resonant and charmed tensor resonant contributions, $B^{+}\to D^{-}{\pi }^{+}{\ell }^{+}{\nu }_{\ell }$ decays receive the non-resonant, the charmed scalar resonant and the charmed tensor resonant contributions, and other $B\to D\pi {\ell }^{+}{\nu }_{\ell }$ decays receive all four kinds of contributions. These results can be used to test the SU(3) flavor symmetry approach in the four-body semileptonic decays by the future LHCb and Belle-II experiments.

   hep-phAdv.High Energy Phys.(2025)·2 citations
5. 05*

   Analysis of Charmed Baryon Decays with Strong Phases under SU(3) Symmetry

   Jin Sun🇰🇷 · Zhi-Peng Xing🇨🇳 · Ruilin Zhu🇨🇳

   The SU(3) analysis is considered a powerful tool in charmed baryon decays. Motivated by recent measurements of anti-triplet charmed baryon two-body decays from the Belle, Belle II, and BESIII Collaborations, we have finally determined the last two IRA form factors, $f^{a\prime }$ and $g^{a\prime }$, which were absent in previous work. By considering both real and complex form factor cases in our work, we find that the phases of the form factors are necessary and that complex form factors can explain the experimental data well. Using the fitted form factors, we further numerically study the equivalence of the SU(3) irreducible representation amplitude (IRA) and topological diagrammatic approach (TDA) methods. We find that the IRA and TDA methods can be numerically equivalent with the addition of the new form factors. Based on the conclusions above, and considering some interesting scenarios, the CP violation effects can be predicted in these processes at the order of $O(10^{-3})$. This suggests a promising opportunity to observe CP violation for the first time in charmed baryon decays. Although our predictions depend on some assumptions, considering that the experimental data is far from sufficient to determine CPV through SU(3) analysis, our study is meaningful and instructive for observing CPV at experimental facilities.

   hep-phEPJC(2025)·13 citations
6. 06*

   Effects of Family Non-universal $Z^{\prime }$ Model in the angular observables of $B\to (\rho ,a_1){\mu }^{+}{\mu }^{-}$ decays

   Nimra Farooq🇵🇰 · Marwah Zaki🇵🇰 · M. Ali Paracha🇵🇰 · Faisal Munir Bhutta🇵🇰

   We present the angular distribution of the four-fold $B\to \rho (\to \pi \pi ){\mu }^{+}{\mu }^{-}$ and $B\to a_1(\to {\rho }_{\parallel ,\perp }\pi ){\mu }^{+}{\mu }^{-}$ decays both in the Standard Model and the family non-universal $Z^{\prime }$ model. At the quark level, these decays are governed by the $b\to d{\mu }^{+}{\mu }^{-}$ transition. Along with different angular observables, we also give predictions of differential branching ratios, forward-backward asymmetry, longitudinal polarization fraction of $\rho$, and $a_1$ mesons. Our analysis shows that the signatures of family non-universal $Z^{\prime }$ model are more distinct in the observables associated with the $B\to \rho (\to \pi \pi ){\mu }^{+}{\mu }^{-}$ decay, compared to that of the $B\to a_1(\to {\rho }_{\parallel ,\perp }\pi ){\mu }^{+}{\mu }^{-}$ decay. Future measurements of the predicted angular observables, both at current and future high energy colliders, will add to the useful complementary data required to clarify the structure of the family non-universal $Z^{\prime }$ model in $|\Delta b|$=$|\Delta d|=1$ processes.

   hep-phCPC(2024)·7 citations
7. 07*

   NNLO PDFs driven by top-quark data

   S. Alekhin🇩🇪 · M. V. Garzelli🇩🇪 · S.-O. Moch🇩🇪 · O. Zenaiev🇩🇪

   We study the impact of state-of-the-art top-quark data collected at the Large Hadron Collider on parton distribution functions (PDFs). Following the ABMP methodology, the fit extracts simultaneously proton PDFs, the strong coupling ${\alpha }_s(M_Z)$ and heavy-quark masses at next-to-next-to-leading order (NNLO) accuracy in QCD. It includes recent high-statistics data on absolute total inclusive cross sections for $t\bar{t}+X$, the sum of $(t+X)$ and $(\bar{t}+X)$ hadroproduction, and normalized inclusive data double-differential in the invariant mass and rapidity of the $t\bar{t}$ pair at $\sqrt{S}=13$ TeV. The gluon PDF at large $x$ and the top-quark mass value derived from these data are well compatible with the previous ABMP16 results, but with significantly smaller uncertainties, reduced by up to a factor of two. At NNLO in QCD we obtain for the strong coupling the value ${\alpha }_s^{(n_f=5)}(M_Z)=0.1150\pm 0.0009$ and for the top-quark mass in the $\overline{\text{mbox}MS}$-scheme $m_t(m_t)=160.6\pm 0.6$ GeV, corresponding to $m_t^{\mathrm{pole}}=170.2\pm 0.7$ GeV in the on-shell scheme. The new fit, dubbed ABMPtt, is publicly released in grids in LHAPDF format.

   hep-phEPJC(2025)·29 citations
8. 08*

   Rotation effect on the spectral function of heavy vector mesons in holographic QCD

   Xiao-Long Wang🇨🇳 · Sheng-Qin Feng🇨🇳

   Exploring heavy vector mesons of the $J/\psi$ and ${\rm Y}(1S)$ is crucial for understanding the quark gluon plasma (QGP) formed in heavy ion collisions. The influences of rotational effect on the properties of the $J/\psi$ and the ${\rm Y}(1S)$ are investigated by incorporating rotation medium into the holographic QCD. It is found that temperature, chemical potential, and rotational radius effects enhance the dissociation process of the $J/\psi$ and the ${\rm Y}(1S)$ states within the medium. This rotation-induced effect is more significant for heavy vector mesons in the transverse direction than that of the longitudinal direction. The first holographic study on the influence of the radius of a homogeneous rotating system on the vector meson spectrum is proposed. It is found that increasing in rotation radius promotes the dissociation of vector mesons of the $J/\psi$ and ${\rm Y}(1S)$. We also find that the dissociation perpendicular to the direction of rotational angular velocity is more significant than that parallel to it at large rational radius.

   hep-phPRD(2024)·12 citations
9. 09*

   Study of ${\tau }^{-}\to \omega {\pi }^{-}{\nu }_{\tau }$ decay in resonance chiral theory with tensor sources

   Feng-Zhi Chen🇨🇳 · Xin-Qiang Li🇨🇳 · Shi-Can Peng🇨🇳 · Ya-Dong Yang🇨🇳 · Yuan-He Zou🇨🇳

   In this work, we make a study of the ${\tau }^{-}\to \omega {\pi }^{-}{\nu }_{\tau }$ decay in the framework of low-energy effective field theory. The $J^{\mathcal{P}G}$ decompositions of the quark currents and the $\omega \pi$ final state show that, besides the Standard Model vector interaction, only the non-standard tensor interaction can have a non-zero contribution to the decay. To discuss its effect, a reliable calculation of the $\omega \pi$ tensor form factors is necessary. After constructing the Lagrangian of resonance chiral theory with external tensor sources, we calculate both the vector and tensor form factors with the relevant resonance couplings determined by combining the QCD short-distance constraints, the fit to the spectral function of ${\tau }^{-}\to \omega {\pi }^{-}{\nu }_{\tau }$ decay, as well as the matching between the $\mathcal{O}(p^4)$ odd-intrinsic-parity operators after integrating out the vector resonances and the $\mathcal{O}(p^6)$ operators of chiral perturbation theory. The new physics effect is then investigated in the distributions of the spectral function and the forward-backward asymmetry of ${\tau }^{-}\to \omega {\pi }^{-}{\nu }_{\tau }$ decay. We find that the spectral function is dominated by the Standard Model, and the non-standard tensor contribution is negligible. However, since the forward-backward asymmetry can be only generated with a non-zero tensor interaction, the observable is quite sensitive to this kind of new physics. A future measurement of the observable at the Belle II experiment as well as at the proposed Tera-Z and STCF facilities is, therefore, strongly called for to check the existence of such a non-standard tensor interaction.

   hep-phJHEP(2024)·2 citations
10. 10*

    Two-loop Quarkonium Hamiltonian in Non-annihilation Channel

    Go Mishima🇯🇵 · Yukinari Sumino🇯🇵 · Hiromasa Takaura🇯🇵

    We calculate the two-loop heavy quarkonium Hamiltonian within potential-NRQCD effective field theory in the non-annihilation channel. This calculation represents the first non-trivial step towards determining the N${}^4$LO Hamiltonian in the weak coupling regime. The large amount of computation is systematically handled by employing the $\beta$ expansion, differential equations for master integrals, and adopting a single-step matching procedure, in contrast to the conventional two-step approach.

    hep-phPRL(2024)·4 citations
11. 11*

    The third family quark mass hierarchy and FCNC in the universal seesaw model

    Takuya Morozumi🇯🇵 · Albertus Hariwangsa Panuluh🇯🇵

    We present the study of the quark sector of the universal seesaw model with $\mathrm{SU}(2{)}_{\mathrm{L}}\times \mathrm{SU}(2{)}_{\mathrm{R}}\times \mathrm{U}(1{)}_{{\mathrm{Y}}^{\prime }}$ gauge symmetry in the massless case of the two lightest quark families. This model aims to explain the mass hierarchy of the third family quark by introducing a vector-like quark (VLQ) partner for each quark. In this model, we introduce $\mathrm{SU}(2{)}_{\mathrm{L}}$ and $\mathrm{SU}(2{)}_{\mathrm{R}}$ Higgs doublets. We derive explicitly the Lagrangian for the quark sector, Higgs sector, and kinetic terms of the gauge fields, starting from the Lagrangian, which is invariant under $\mathrm{SU}(2{)}_{\mathrm{L}}\times \mathrm{SU}(2{)}_{\mathrm{R}}\times \mathrm{U}(1{)}_{{\mathrm{Y}}^{\prime }}$ gauge symmetry. At each stage of the symmetry breaking, we present the Lagrangian with the remaining gauge symmetry. Additionally, we investigate the flavor-changing neutral currents (FCNC) of Higgs ($h$) and $Z$-boson in the interaction with the top, heavy top, bottom, and heavy bottom quark.

    hep-phhep-exPTEP(2024)·17 citations
12. 12*

    Spontaneous Symmetry Breaking: From the Effective Action to Cosmological Phase Transitions in the Standard Model and Beyond

    Apostolos Giovanakis🇬🇷

    The primary objective of this work is to investigate the cosmological phase transitions in the early Universe, with a focus on the electroweak phase transition in the Standard Model and its extensions. In the Standard Model, the spontaneously broken electroweak symmetry at zero temperature is restored in the early Universe due to finite-temperature effects. This phenomenon is studied using the effective potential at finite temperatures, which determines the true vacuum state of the theory. Symmetry restoration at high temperatures is also studied by the finite-temperature field theory introduced to derive the Feynman rules at finite temperatures using the imaginary-time formalism. Furthermore, we present the theory of cosmological phase transitions, focusing on the concepts of thermal tunneling and bubble nucleation. We additionally discuss the observed baryon asymmetry of the Universe to formulate the conditions for baryogenesis and describe electroweak baryogenesis. Therefore, the one-loop effective potential in the Standard Model at finite temperatures is derived in detail including the ring corrections to study further the electroweak baryogenesis. Our results indicate that the electroweak phase transition is not strong enough to explain the observed baryon asymmetry of the Universe. On the other hand, the real singlet extensions of the Standard Model describe a strong enough electroweak phase transition and the observed baryon asymmetry of the Universe. These extensions are also discussed including a dimension-six operator, which originates from an effective field theory. In particular, the parameter space of this singlet extension is examined extensively, while it is restricted by numerous phenomenological constraints, such as the invisible Higgs decay width.

    hep-phhep-th1 citation
13. 13*

    The plan for a super $\eta$ factory at Huizhou accelerator complex

    Xu-Rong Chen🇨🇳 · Xiong-Hong He🇨🇳 · Qiang Hu🇨🇳 · De-Xu Lin🇨🇳 · Yang Liu🇨🇳 · Hao Qiu🇨🇳 · Xu Sun🇨🇳 · Ye Tian🇨🇳 · Rong Wang🇨🇳 · Hong-Lin Zhang🇨🇳 · Ya-Peng Zhang🇨🇳 · Cheng-Xin Zhao🇨🇳

    As an approximate Goldstone boson with zero quantum number and zero standard model charge, the decay processes of long-lived $\eta$ meson offer a unique opportunity to explore new physics beyond the standard model and new sources of CP violation, as well as test the low-energy QCD theory and measure the fundamental parameters of light quarks. To pursue these goals in the physics frontiers, we propose a plan to construct a super $\eta$ factory at HIAF high-energy terminal or at CiADS after its energy upgrade. The high-intensity proton beam at HIAF enables the production of a vast number of $\eta$ samples, exceeding $10^{13}$ events per year in the first stage, utilizing multiple layers of thin targets made of light nucleus. This paper presents the physics goals, the first-version conceptual design of the spectrometer, and some preliminary simulation results.

    hep-phNucl.Sci.Tech.(2025)·18 citations
14. 14*

    Revisiting the origin of neutrino flavor transformations

    Shi-Biao Zheng🇨🇳

    To account for neutrino oscillations, it was postulated that the neutrino has nonvanishing mass and each flavor eigenstate is formed by a quantum superposition of three distinct mass eigenstates, whose probability amplitudes interfere with each other during its propagation. However, I find that a neutrino or antineutrino produced by the decay of an unstable particle cannot be in such a superposition, as different mass eigenstates, if they exist, are necessarily correlated with different momentum states of the composite system produced by the decay, which would destroy the quantum coherence among these mass eigenstates. I further find that the states of a neutrino and an electron become nonseparable after their charged-current interaction. This nonseparability leads to decoherence for neutrinos propagating in matter, but was not taken into consideration in previous investigations of the matter effect. Due to this decoherence, the deficit of solar electron neutrinos cannot exceed 1/2 based on the aforementioned postulation even if the corresponding superposition of mass eigenstates can be produced. These results unambiguously show that the origin of neutrino flavor transformations needs to be revisited. I propose an alternative mechanism that can reasonably account for neutrino transformations. It is based on virtual excitation of the Z bosonic field diffusing over the space. During the propagation, the neutrino can continually excite and then immediately re-absorb a virtual Z boson. This virtual bosonic excitation produces a backaction on the neutrino, enabling it to oscillate among three flavors. When the neutrino propagates in matter, its behavior is determined by the competition between the coherent flavor transformation and decoherence effect resulting from scatterings.

    hep-phquant-ph6 citations
15. 15*

    Dark matter-electron scattering and freeze-in scenarios in the light of $Z^{\prime }$ mediation

    Basabendu Barman🇮🇳 · Arindam Das🇯🇵 · Sanjoy Mandal🇰🇷

    We investigate dark matter (DM)-electron scattering in a minimal $U(1{)}_X$ extension of the Standard Model (SM), where the DM can appear as a Majorana fermion, a complex singlet scalar or a Dirac fermion. To study bounds on the $U(1{)}_X$ gauge coupling $(g_X)$ and new gauge boson mass $(M_{Z^{\prime }})$, from DM-electron scattering, we consider several direct search experiments like CDMS, DAMIC, SENSEI, PandaX-II, DarkSide-50 and XENON1T-S2 for different $U(1{)}_X$ charges. In this set-up we consider DM production via freeze-in both in radiation dominated and modified cosmological background to project sensitivities on $g_X-M_{Z^{\prime }}$ plane satisfying observed relic abundance. DM-electron scattering could provide comparable, or even stronger bounds than those obtained from the electron/ muon $(g-2)$, low energy scattering and intensity frontier experiments within 0.01 GeV $\lesssim M_{Z^{\prime }}\lesssim$ 0.1 GeV. Constrains from freeze-in could provide stronger sensitivities for $M_{Z^{\prime }}\gtrsim \mathcal{O}(1)$ GeV, however, these limits are comparable to those obtained from LHCb, LEP experiments for $\mathcal{O}(10)$ GeV $\lesssim M_{Z^{\prime }}\lesssim 150$ GeV. In future, electron-muon scattering (MUonE), proton (FASER, DUNE) and electron/positron (ILC) beam dump experiments could probe these parameters.

    hep-phastro-ph.COPRD(2024)·21 citations
16. 16*

    Nonleptonic B-decays at NNLO

    Manuel Egner🇩🇪

    The decay of B mesons can be predicted within the Heavy Quark Expansion as the decay of a free bottom quark plus corrections which are suppressed by powers of $1/m_b$. This contribution to Loops&Legs 2024 describes the calculation of the NNLO QCD corrections to nonleptonic decays of a free bottom quark including charm quark mass effects. In particular it outlines the challenges in connection to the computation of master integrals, the renormalization of the effective operators and the problems which arise from calculating traces with ${\gamma }_5$ in $d$ dimensions.

    hep-phPoS(2024)·0 citations
17. 17*

    Higgs-Portal Spin-1 Dark Matter with Parity-Violating Interaction

    Kimiko Yamashita🇯🇵

    We introduce the spin-1 $U(1{)}_X$ gauged field $X$ with $Z_2$ odd dark parity to evade the current strong constraints on kinetic mixing. Then, $X$ becomes stable and a candidate for the dark matter. The lowest mass dimension of interaction is six, and the type is the Higgs portal. Two types of dim-6 operators are introduced. We consider the freeze-out dark matter scenario. With the limit of null momentum transfer, a parity odd operator is free from the direct detection constraints. Accordingly, the strong constraints on a parity even operator indicate turning on this parity odd operator to realize the dark matter relic density of the Universe. With the 1 TeV cut-off scale, our dark matter of around 400 GeV mass can explain the dark matter relic density and is allowed from the LUX-ZEPLIN experiment of the direct detection.

    hep-phhep-exJHEP(2024)·6 citations
18. 18*

    Dark Photon Dark Matter in Quantum Electromagnetodynamics and Detection at Haloscope Experiments

    Chang-Jie Dai🇨🇳 · Tong Li🇨🇳 · Rui-Jia Zhang🇨🇳

    The ultralight dark photon is one of intriguing dark matter candidates. The interaction between the visible photon and dark photon is introduced by the gauge kinetic mixing between the field strength tensors of the Abelian gauge groups in the Standard Model and dark sector. The relativistic electrodynamics was generalized to quantum electromagnetodynamics (QEMD) in the presence of both electric and magnetic charges. The photon is described by two four-potentials corresponding to two $U(1)$ gauge groups and satisfying non-trivial commutation relations. In this work, we construct the low-energy dark photon-photon interactions in the framework of QEMD and obtain new dark photon-photon kinetic mixings. The consequent field equations and the new Maxwell's equations are derived in this framework. We also investigate the detection strategies of dark photon as light dark matter as well as the generic kinetic mixings at haloscope experiments.

    hep-phhep-exCPC(2025)·1 citation
19. 19*

    Indirect detection constraints on semi-annihilation of inert scalar multiplets

    Hugues Beauchesne🇹🇼 · Cheng-Wei Chiang🇹🇼

    Certain models of inert multiplets allow for semi-annihilation processes, in which two dark matter candidates annihilate to a dark matter particle and a non-dark matter particle. The existence of these processes can alleviate certain constraints and substantially modify the indirect detection signal. In this paper, we study current indirect detection constraints on the semi-annihilation of inert scalar multiplets. We show that there exist gauge numbers for which dark matter can be thermally produced and be compatible with indirect detection constraints even for very cuspy galactic dark matter density profiles.

    hep-phJHEP(2025)·2 citations
20. 20*

    Gemini Dark Matter

    Andrew Cheek🇨🇳 · Yu-Cheng Qiu🇨🇳 · Liang Tan🇨🇳

    The $S_8/{\sigma }_8$ tension in the large scale structure can be explained by decaying dark matter with an almost degenerate spectrum and small enough decay width. Here we propose the Gemini dark matter model, which contains a heavy mother particle ${\chi }_3$ and two twins ${\chi }_{1/2}$ which are almost degenerate in mass and are produced at the same time. The dark sector is charged under the same Froggatt-Nielsen symmetry that can explain the hierarchy of the Standard model Yukawa couplings. The slightly heavier ${\chi }_2$ decays into ${\chi }_1$ and the axionic component of the flavon, which washes out the small scale structure and resolves $S_8/{\sigma }_8$ tension. We present the production mechanism of Gemini dark matter and viable parameter regions. We find that despite the preferred dark matter mass being $\mathcal{O}(1)$--$\mathcal{O}(100)$ keV, they constitute cold dark matter. The Gemini dark matter model predicts an abundance of dark radiation that will be probed in future measurements of the cosmic microwave background.

    hep-phastro-ph.COPRD(2024)·7 citations
21. 21*

    Relevance of the coupled channels in the $\varphi$p and ${\rho }^0$p Correlation Functions

    A. Feijoo🇩🇪 · M. Korwieser🇩🇪 · L. Fabbietti🇩🇪

    The vector meson-baryon interaction in a coupled channel scheme is revisited within the correlation function framework. As illustrative cases to reveal the important role played by the coupled channels, we focus on the $\varphi$p and ${\rho }^0$p systems given their complex dynamics and the presence of quasi-bound states or resonances in the vicinity of their thresholds. We show that the $\varphi$p femtoscopic data provide novel information about a $N^{\ast }$ state present in the experimental region and anticipate the relevance of a future ${\rho }^0$p correlation function measurement in order to pin down the $S=0,Q=+1$ vector meson-baryon interaction as well as to disclose the characterizing features of the $N^{\ast }(1700)$ state.

    hep-phnucl-thPRD(2025)·38 citations
22. 22*

    Probing leptophobic dark sector with a pseudoscalar portal in the NA64 experiment at CERN

    Sergei N. Gninenko🇷🇺 · Dmitry V. Kirpichnikov🇷🇺 · Nikolai V. Krasnikov🇷🇺 · Sergey Kuleshov🇨🇱 · Valery E. Lyubovitskij🇩🇪 · Alexey S. Zhevlakov🇷🇺

    We propose the possibility of discovering a light pseudoscalar particle $a$, axion-like particle (ALP), interacting mainly with quarks using the electron and photon scattering reaction chain $e+Z\to e+\gamma +Z$; $\gamma +Z\to a+Z$ on nuclei in the NA64 experiment at the CERN SPS. We consider the mixing of ALP with light pseudoscalar mesons $P=\pi ,\eta ,{\eta }^{\prime }$ with taking into account of the ALP mass explicitly breaking the Peccei-Quinn symmetry. It could open invisible channels of ALP decaying into dark fermion matter by analogy with $P$ mesons decays. New bounds on the coupling strengths of the ALP with quarks and of pseudoscalar mesons with dark fermions are obtained by using existing upper bounds on invisible decay modes of $P$s including those recently derived by NA64. We also study a scenario when the $a$ plays the role of a messenger in the communication between our world and the dark sector. New upper limits on axion couplings with quarks and its mixing parameters with $\pi ,\eta ,{\eta }^{\prime }$ mesons are established.

    hep-phJHEP(2025)·3 citations
23. 23*

    From the $P_{\psi }^N$/$P_{\psi s}^{\Lambda }$ to ${\bar{T}}_{cc}^f$: symmetry analysis to the interactions of the $(\bar{c}q)(\bar{c}q)$/$(ccq)(\bar{c}q)$/$(ccq)(ccq)$ di-hadron systems

    Kan Chen🇨🇳 · Bo Wang🇨🇳

    We investigate the interactions of the $(\bar{c}q)(\bar{c}q)$/$(ccq)(\bar{c}q)$/$(ccq)(ccq)$ di-hadron systems based on a contact lagrangian possessing the SU(3) flavor and SU(2) spin symmetries. Under the assumptions of two scenarios for the $J^P$ quantum numbers of the $P_{\psi }^N(4440)$ and $P_{\psi }^N(4457)$ states, we obtain the parameters (${\tilde{g}}_s$, ${\tilde{g}}_a$) introduced from this contact lagrangian. Then we include the SU(3) breaking effect by introducing a factor $g_x$, this quantity can be further constrained by the experimental mass of the $P_{\psi s}^{\Lambda }(4338)$ state. We can reproduce the mass of the $T_{cc}^f(3875)$ state with the parameters extracted from the observed $P_{\psi }^N$ states, this consistency indicates a unified description of the di-hadron molecular states composed of two heavy-light hadrons. With the same parameters, we discuss the possible mass spectra of the ${\bar{T}}_{cc}^f$/$P_{\psi c}^{\Lambda }$/$H_{{\Omega }_{ccc}c}^{\Lambda }$ systems. Then we proceed to discuss the existences of the ${\bar{T}}_{cc\bar{s}}^{\theta }$/$P_{\psi cs}^N$/$H_{{\Omega }_{ccc}cs}^N$ states by investigating the SU(3) breaking effects. Our results show that the states in the ${\bar{T}}_{cc\bar{s}}^{\theta }$/$P_{\psi cs}^N$ systems can hardly form bound states, while the states in the $H_{{\Omega }_{ccc}cs}^N$ system can form bound states due to their larger reduced masses.

    hep-phhep-exPRD(2024)·3 citations
24. 24*

    Higgs Decay to $Z\gamma$ in the Minimal Supersymmetric Standard Model and Its Nonholomorphic Extension

    Sajid Israr🇵🇰 · Muhammad Rehman🇵🇰

    Recent measurements of $h\to Z\gamma$ from CMS and ATLAS indicate an excess over Standard Model (SM) predictions, suggesting the presence of new physics. In this work, we investigate the $h\to Z\gamma$ decay within the minimal supersymmetric standard model (MSSM) and its nonholomorphic extension, the NHSSM. Calculations are performed using the FeynArts/FormCalc setup, utilizing the pre-existing model file for MSSM and generating the NHSSM model file with the support of {\tt SARAH}. In the allowed parameter space, MSSM contributions to $h\to Z\gamma$ can significantly surpass SM predictions reaching to the value $\Gamma (h\to Z\gamma )=9.77\times 10^{-6}\text{GeV}$, thereby bringing $\Gamma (h\to Z\gamma )$ closer to the experimental value. The SM predicted value deviates from the experimental value by $1.7\sigma$. However, the MSSM contributions can reduce this deviation to less than $1\sigma$. In contrast, NHSSM contributions remain negligible and do not produce sizable corrections to the $h\to Z\gamma$ decay width.

    hep-phEur.Phys.J.Plus(2025)·17 citations
25. 25*

    Anomalous triple gauge couplings in $e^{-}{e}^{+}\to 4j$: Role of polarizations, spin correlations and interference

    Amir Subba🇮🇳 · Ritesh K. Singh🇮🇳

    We investigate the anomalous charged triple gauge boson couplings generated via $SU(2{)}_l\times U(1{)}_Y$ gauge invariant dimension-6 operators with final state four jet events in an $e^{-}{e}^{+}$ Collider at $\sqrt{s}=250$~GeV. We consider all the leading order contributions including the contribution from the interference of $W^{-}{W}^{+}$ diagrams with other possible diagrams. The tagging of two $W$ bosons with a pair of jets is done using the jet charge, while the decay products of $W^{\prime }$s are tagged as \emph{up/down}-type using boosted decision trees to construct polarizations and spin correlations. Marginalized limits on five anomalous couplings are obtained by Markov Chain Monte Carlo analysis using polarizations, spin correlations, and cross~section. We found that the full-hadronic channel provides tighter limits on anomalous couplings than compared to the usually sought-after clean semi-leptonic channel, owing to the large contribution from interference.

    hep-ph1 citation
26. 26*

    Effects of saturation and fluctuating hotspots for flow observables in ultrarelativistic heavy-ion collisions

    Henry Hirvonen🇫🇮 · Mikko Kuha🇫🇮 · Jussi Auvinen🇫🇮 · Kari J. Eskola🇫🇮 · Yuuka Kanakubo🇫🇮 · Harri Niemi🇫🇮

    We investigate the effects of saturation dynamics on midrapidity flow observables by adding fluctuating hotspots into the novel Monte Carlo EKRT (MC-EKRT) event generator for high-energy nuclear collisions. We demonstrate that the intensity of the saturation effects significantly affects the ratio between the flow coefficients $v_3$ and $v_2$ at the LHC. Adding a hotspot substructure to the nucleons enhances the saturation effects and improves the agreement with the measured data. We show that the collision-energy dependence of the flow coefficients obtained using the MC-EKRT initial states with hotspots is improved in comparison with the earlier event-by-event EKRT model. In addition, we present the results for the charged hadron multiplicity distribution in Pb+Pb collisions at the LHC, and show that the minijet-multiplicity originating fluctuations of the saturation scale included in MC-EKRT, as well as the presence of hotspots, are necessary for describing the measured large-multiplicity tail in the distribution.

    hep-phnucl-thPRC(2024)·6 citations
27. 27*

    Search for charged Higgs bosons through vector-like top quark pair production at the LHC

    Abdesslam Arhrib🇲🇦 · Rachid Benbrik🇲🇦 · Mbark Berrouj🇲🇦 · Mohammed Boukidi🇲🇦 · Bouzid Manaut🇲🇦

    We investigate the discovery prospects for a vector-like top partner (VLT) in the Type-II Two-Higgs-Doublet Model (2HDM-II) extended by a vector-like quark doublet ($TB$) at the 14~TeV LHC. The study focuses on the pair production process $pp\to T\bar{T}\to b{H}^{+}\bar{b}{H}^{-}\to b(tb)\bar{b}(\bar{t}b)$, yielding fully hadronic final states characterized by high $b$-jet multiplicity. Two analysis strategies are employed, requiring at least four or five $b$-tagged jets (4$b$ and 5$b$), to exploit the signal topology. Assuming a charged Higgs mass of $m_{H^{\pm }}\sim 600$~GeV and a systematic uncertainty of $\delta =5\%$, the 4$b$ channel enables discovery up to $m_T\sim 1200$~GeV at $\mathcal{L}=300{\text{fb}}^{-1}$, while the 5$b$ analysis extends the reach to $m_T\sim 1300$~GeV. At higher luminosities of 1000--3000~fb${}^{-1}$, the 5$b$ strategy achieves discovery sensitivity up to $m_T\sim 1400$~GeV. The reach is significantly reduced as $m_{H^{\pm }}$ increases, due to the suppression of the $\text{BR}(T\to H^{+}b)$: for $m_{H^{\pm }}\sim 1000$~GeV, discovery becomes unattainable across all luminosity and systematic uncertainty configurations. Sensitivity is also strongly impacted by systematic uncertainties: for $\delta =10\%$ and $m_{H^{\pm }}<1000$~GeV, discovery remains viable up to $m_T\sim 1200$~GeV in the 5$b$ analysis, while for $\delta =20\%$, no discovery is achievable for $m_T\ge 1000$~GeV.

    hep-phPRD(2025)·18 citations
28. 28*

    Higgs-boson production in the full theory at NNLO+PS

    Marco Niggetiedt🇩🇪 · Marius Wiesemann🇩🇪

    We consider the production of a Standard-Model (SM) Higgs boson in gluon fusion in hadronic collisions and compute the QCD corrections up to next-to-next-to-leading order (NNLO) and match them to parton showers (NNLO+PS). The complete dependence on the top-quark mass is taken into account without making any approximations to the top quark loops mediating the coupling between the gluons and the Higgs boson. To this end, we have included the $gg\to H$ amplitudes up to three loops and the $pp\to H$+jet amplitudes up to two loops in the full SM theory. This is the first fully differential calculation of the top-quark mass effects up to NNLO in QCD, and we study their impact on relevant observables for the LHC.

    hep-phhep-exPLB(2024)·15 citations
29. 29*

    Towards the next Kira release

    Fabian Lange🇨🇭 · Johann Usovitsch🇨🇭 · Zihao Wu🇨🇳

    The reduction of Feynman integrals to a basis of master integrals plays a crucial role for many high-precision calculations and Kira is one of the leading tools for this task. In these proceedings we discuss some of the new features and improvements currently being developed for the next release.

    hep-phhep-thPoS(2024)·5 citations
30. 30*

    Precise determination of the $\eta \Lambda$ scattering length and effective range and relationship to the $\Lambda (1670)$ resonance

    Man-Yu Duan🇨🇳 · Melahat Bayar🇹🇷 · Eulogio Oset🇪🇸

    We use the Belle data on the $K^{-}p$ mass distribution of the ${\Lambda }_c^{+}\to p{K}^{-}{\pi }^{+}$ reaction near the $\eta \Lambda$ threshold to determine the $\eta \Lambda$ scattering length and effective range. We show that from these data alone we can determine the value of $a$ with better precision than so far determined, and the value of $r_0$ for the first time. The addition of the $K^{-}p\to \eta \Lambda$ data allows us to improve the precision of these magnitudes, with errors smaller than $15\%$. We also determine with high precision the pole position of the $\Lambda (1670)$.

    hep-phnucl-thPLB(2024)·16 citations
31. 31*

    Unveiling desert region in inert doublet model assisted by Peccei-Quinn symmetry

    Anupam Ghosh🇮🇳 · Partha Konar🇮🇳

    The Inert Higgs Doublet model (IDM), assisted by Peccei-Quinn (PQ) symmetry, offers a simple but natural framework of a dark sector that accommodates Weakly Interacting Massive Particle (WIMP) and axion as dark matter components. Spontaneous breaking of $U(1{)}_{PQ}$ symmetry, which was originally proposed as an elegant solution to the strong charge-parity (CP) problem, also ensures the stability of WIMP through a residual ${\mathbb{Z}}_2$ symmetry. Interestingly, additional fields necessitated by PQ symmetry further enrich the dark sector. These include a scalar field proprietor for axion DM and a vector-like quark (VLQ) that acts as a portal for the dark sector through Yukawa interactions. Moreover, this combination of the axion and WIMP components satisfies the observed DM relic density and reopens the phenomenologically exciting region of the IDM parameter space where the WIMP mass falls between 100 - 550 GeV. We investigate the model-independent pair production of VLQs exploring this region at the Large Hadron Collider (LHC), incorporating the effects of next-to-leading order (NLO) QCD corrections. After production, each VLQ decays into a top or bottom quark accompanied by an inert scalar, a consequence of the residual ${\mathbb{Z}}_2$ symmetry. Utilising relevant observables with a leptonic search channel and employing multivariate analysis, we demonstrate the ability of this analysis to exclude a significant portion of the parameter space with an integrated luminosity of 300 ${\text{fb}}^{-1}$.

    hep-phJHEP(2024)·17 citations
32. 32*

    Bounds to strong gravity from electron-positron annihilations near threshold

    Nathaniel Alden🇺🇸 · Roberto Onofrio🇺🇸

    We discuss bounds to strong gravity arising from annihilation of electron and positrons and the corresponding enhancement of the cross section for the production of massive particles. Two complementary examples are discussed, the case of the $e^{+}{e}^{-}\to W^{+}{W}^{-}$ processes, with maximum mass and short lifetime for the particle pairs in the final state, and the case of electron positron annihilation into heavier charged lepton pairs, $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}$ and $e^{+}{e}^{-}\to {\tau }^{+}{\tau }^{-}$. These bounds may be improved by the next generation of electron-positron colliders, and are complementary to bounds arising from direct graviton searches.

    hep-phgr-qchep-exphysics.ins-detPRD(2024)·1 citation
33. 33*

    New multiloop capabilities of FeynCalc 10

    Vladyslav Shtabovenko🇩🇪

    We briefly introduce new multiloop capabilities of the Mathematica package FeynCalc 10 and a collection of interfaces connecting FeynCalc to such popular tools as QGRAF, Fiesta, pySecDec, LoopTools, KIRA, FIRE or Fermat. In addition to that, we showcase the application of these codes to the ongoing study of the soft-overlap contribution to $B_c\to {\eta }_c$ transition form factors at large hadronic recoil.

    hep-phPoS(2024)·6 citations
34. 34*

    Quark-Hadron Duality Violations and Higher-Order $1/m_b$ Corrections in Inclusive Semileptonic $B$ Decays

    Thomas Mannel🇩🇪 · Ilija S. Milutin🇩🇪 · Rens Verkade🇳🇱 · K. Keri Vos🇳🇱

    The theoretical description and data for inclusive semileptonic $B$ decays have reached incredible precision. This motivated us to re-animate the discussion of possible Quark-Hadron Duality violations. There seems that there is currently no evidence of a failure of the Heavy Quark Expansion (HQE) used to compute observables for these decays. However, we might arrive at a point where an asymptotic behaviour of the HQE would limit a further increase of precision. We discuss this possibility and suggest a simple model, which can be used to study the effects of higher orders in the $1/m_b$ expansion and possible quark-hadron duality violations. We devise observables sensitive only to such higher-order effects to test the behaviour of the HQE. Using these observables we obtain a first estimate of possible quark-hadron duality violations using the measured $q^2$ moments.

    hep-phJHEP(2024)·4 citations
35. 35*

    Interpretation of recently discovered single bottom baryons in the relativistic flux tube model

    Pooja Jakhad🇮🇳 · Juhi Oudichhya🇮🇳 · Ajay Kumar Rai🇮🇳

    Following recent experimental progress in the study of bottom baryons, we systematically calculate the mass spectra of ${\Lambda }_b$, ${\Xi }_b$, ${\Sigma }_b$, ${\Xi }_b^{{}^{\prime }}$, and ${\Omega }_b$ baryons with a quark-diquark picture in the framework of a relativistic flux tube model with spin-dependent interactions in the j-j coupling scheme. Furthermore, we calculate the strong decay width of bottom baryons decaying into a bottom baryon and a light pseudoscalar meson. A good agreement is found between the calculated masses and the experimentally available masses of singly bottom baryons. %We interpret ${\Sigma }_b(6097)$ as a $1P(3/2^{-})$ state, ${\Xi }_b(6100)$ as $1P(1/2^{-})$ state of ${\Xi }_b$ baryon, ${\Xi }_b(6227)$ as a $1P(1/2^{-})$ or $1P(3/2^{-})$ state of ${\Xi }_b^{\prime }$ baryon, ${\Xi }_b(6327)$ as a $1P(3/2^{-})$ state of ${\Xi }_b^{\prime }$ baryon, and ${\Xi }_b(6333)$ as a $1P(3/2^{-})$ state of ${\Xi }_b^{\prime }$ baryon. By analysing both mass spectra and strong decay widths, we interpret ${\Sigma }_b(6097)$ as a $1P(3/2^{-})$ state and ${\Xi }_b(6100)$ as a $1P(1/2^{-})$ state of ${\Xi }_b$ baryon. The ${\Xi }_b(6227)$ is identified to be an orbital excitation $1P$ of the ${\Xi }_b^{{}^{\prime }}$ baryon with $J^P=3/2^{-}$. Further, we determine ${\Xi }_b(6327)$ and ${\Xi }_b(6333)$ as a $1P(3/2^{-})$ state and $1P(5/2^{-})$ state, respectively, of ${\Xi }_b^{{}^{\prime }}$ baryon. From the obtained mass spectra, we construct the Regge trajectories in the $(J,M^2)$ plane, which are found to be essentially linear, parallel, and equidistant. Our predictions for higher orbital and radial excited states can help experimentalists identify missing excited states of singly bottom baryons.

    hep-phPRD(2024)·17 citations
36. 36*

    Hadronic Top Quark Polarimetry with ParticleNet

    Zhongtian Dong🇺🇸 · Dorival Gonçalves🇺🇸 · Kyoungchul Kong🇺🇸 · Andrew J. Larkoski🇺🇸 · Alberto Navarro🇺🇸

    Precision studies for top quark physics are a cornerstone of the Large Hadron Collider program. Polarization, probed through decay kinematics, provides a unique tool to scrutinize the top quark across its various production modes and to explore potential new physics effects. However, the top quark most often decays hadronically, for which unambiguous identification of its decay products sensitive to top quark polarization is not possible. In this Letter, we introduce a jet flavor tagging method to significantly improve spin analyzing power in hadronic decays, going beyond exclusive kinematic information employed in previous studies. We provide parametric estimates of the improvement from flavor tagging with any set of measured observables and demonstrate this in practice on simulated data using a Graph Neural Network (GNN). We find that the spin analyzing power in hadronic decays can improve by approximately 20% (40%) compared to the kinematic approach, assuming an efficiency of 0.5 (0.2) for the network.

    hep-phhep-exPLB(2025)·18 citations
37. 37*

    ALP leptogenesis

    Martina Cataldi🇩🇪 · Alberto Mariotti🇧🇪 · Filippo Sala🇮🇹 · Miguel Vanvlasselaer🇧🇪

    We propose a novel realisation of leptogenesis that relies on the out-of-equilibrium decay of an axion-like particle (ALP) into right-handed Majorana neutrinos (RHNs) in the early Universe. With respect to standard thermal leptogenesis, our mechanism lowers by two orders of magnitude the RHN mass, or the tuning in the RHN mass splittings, needed to reproduce the baryon asymmetry of the Universe and neutrino masses. We find that ALP leptogenesis requires $m_a>10^4$ GeV and $f_a>10^{11}$ GeV for the ALP mass and decay constant, and predicts an early period of matter domination induced by the ALP in parts of its parameter space. We finally provide a viable supersymmetric realisation of ALP leptogenesis where the ALP is the $R$-axion, which accommodates GeV gravitino dark matter and predicts RHN below 10 TeV.

    hep-phastro-ph.COJHEP(2024)·14 citations
38. 38*

    Dark Matter Raining on DUNE and Other Large Volume Detectors

    Javier F. Acevedo🇺🇸 · Joshua Berger🇺🇸 · Peter B. Denton🇺🇸

    Direct detection is a powerful means of searching for particle physics evidence of dark matter (DM) heavier than about a GeV with $\mathcal{O}(kiloton)$ volume, low-threshold detectors. In many scenarios, some fraction of the DM may be boosted to large velocities enhancing and generally modifying possible detection signatures. We investigate the scenario where 100% of the DM is boosted at the Earth due to new attractive long-range forces. This leads to two main improvements in detection capabilities: 1) the large boost allows for detectable signatures of DM well below a GeV at large-volume neutrino detectors, such as DUNE, Super-K, Hyper-K, and JUNO, as possible DM detectors, and 2) the flux at the Earth's surface is enhanced by a focusing effect. In addition, the model leads to a significant anisotropy in the signal with the DM flowing dominantly vertically at the Earth's surface instead of the typical approximately isotropic DM signal. We develop the theory behind this model and also calculate realistic constraints using a detailed GENIE simulation of the signal inside detectors.

    hep-phastro-ph.HEhep-exJHEP(2024)·11 citations
39. 39*

    Optimizing Entanglement and Bell Inequality Violation in Top Anti-Top Events

    Kun Cheng🇺🇸 · Tao Han🇺🇸 · Matthew Low🇺🇸

    A top quark and an anti-top quark produced together at colliders have correlated spins. These spins constitute a quantum state that can exhibit entanglement and violate Bell's inequality. In realistic collider experiments, most analyses allow the axes, as well the Lorentz frame to vary event-by-event, thus introducing a dependence on the choice of event-dependent basis leading us to adopt "fictitious states," rather than genuine quantum states. The basis dependence of fictitious states allows for an optimization procedure, which makes the usage of fictitious states advantageous in measuring entanglement and Bell inequality violation. In this work, we show analytically that the basis which diagonalizes the spin-spin correlations is optimal for maximizing spin correlations, entanglement, and Bell inequality violation. We show that the optimal basis is approximately the same as the fixed beam basis (or the rotated beam basis) near the $t\bar{t}$ production threshold, while it approaches the helicity basis far above threshold. Using this basis, we present the sensitivity for entanglement and Bell inequality violation in $t\bar{t}$ events at the LHC and a future $e^{+}{e}^{-}$ collider. Since observing Bell inequality violation appears to be quite challenging experimentally, and requires a large dataset in collider experiments, choosing the optimal basis is crucially important to observe Bell inequality violation. Our method and general approach are equally applicable to other systems beyond $t\bar{t}$, including interactions beyond the Standard Model.

    hep-phhep-thquant-phPRD(2025)·68 citations
40. 40*

    Hawking Radiation of Nonrelativistic Scalars: Applications to Pion and Axion Production

    Hao-Ran Cui🇺🇸 · Yuhsin Tsai🇺🇸 · Tao Xu🇺🇸

    In studying secondary gamma-ray emissions from Primordial Black Holes (PBHs), the production of scalar particles like pions and axion-like particles (ALPs) via Hawking radiation is crucial. While previous analyses assumed relativistic production, asteroid-mass PBHs, relevant to upcoming experiments like AMEGO-X, likely produce pions and ALPs non-relativistically when their masses exceed 10 MeV. To account for mass dependence in Hawking radiation, we revisit the greybody factors for massive scalars from Schwarzschild black holes, revealing significant mass corrections to particle production rates compared to the projected AMEGO-X sensitivity. We highlight the importance of considering non-relativistic ${\pi }^0$ production in interpreting PBH gamma-ray signals, essential for determining PBH properties. Additionally, we comment on the potential suppression of pion production due to form factor effects when producing extended objects via Hawking radiation. We also provide an example code for calculating the Hawking radiation spectrum of massive scalar particles.

    hep-phastro-ph.COJHEP(2024)·5 citations
41. 41*

    Axion Relic Pockets -- a theory of dark matter

    Pierluca Carenza🇸🇪 · Joshua Eby🇸🇪 · Oksana Iarygina🇸🇪 · M.C. David Marsh🇸🇪

    We propose a new theory of dark matter based on axion physics and cosmological phase transitions. We show that theories in which a gauge coupling increases through a first-order phase transition naturally result in `axion relic pockets': regions of relic false vacua stabilised by the pressure from a kinematically trapped, hot axion gas. Axion relic pockets provide a viable and highly economical theory of dark matter: the macroscopic properties of the pockets depend only on a single parameter (the phase transition temperature). We describe the formation, evolution and present-day properties of axion relic pockets, and outline how their phenomenology is distinct from existing dark matter paradigms. We briefly discuss how laboratory experiments and astronomical observations can be used to test the theory, and identify gamma-ray observations of magnetised, dark-matter-dense environments as particularly promising.

    hep-phastro-ph.COhep-thJHEP(2024)·5 citations
42. 42*

    Scattering amplitudes in the Randall-Sundrum model with brane-localized curvature terms

    R. Sekhar Chivukula🇺🇸 · Kirtimaan A. Mohan🇺🇸 · Dipan Sengupta🇦🇺 · Elizabeth H. Simmons🇺🇸 · Xing Wang🇺🇸

    In this paper we investigate the scattering amplitudes of spin-2 Kaluza-Klein (KK) states in Randall-Sundrum models with brane-localized curvature terms. We show that the presence of brane-localized curvature interactions modifies the properties of (4D) scalar fluctuations of the metric, resulting in scattering amplitudes of the massive spin-2 KK states which grow as $\mathcal{O}(s^3)$ instead of $\mathcal{O}(s)$. We discuss the constraints on the size of the brane-localized curvature interactions based on the consistency of the Sturm-Liouville mode systems of the spin-2 and spin-0 metric fluctuations. We connect the properties of the scattering amplitudes to the diffeomorphism invariance of the compactified KK theory with brane-localized curvature interactions. We verify that the scattering amplitudes involving brane-localized external sources (matter) are diffeomorphism-invariant, but show that those for matter localized at an arbitrary point in the bulk are not. We demonstrate that, in Feynman gauge, the spin-0 Goldstone bosons corresponding to helicity-0 states of the massive spin-2 KK bosons behave as a tower of Galileons, and that it is their interactions that produce the high-energy behavior of the scattering amplitudes. We also outline the correspondence between our results and those in the Dvali-Gabadadze-Porrati (DGP) model. In an appendix we discuss the analogous issue in extra-dimensional gauge theory, and show that the presence of a brane-localized gauge kinetic-energy term does not change the high-energy behavior of corresponding KK vector boson scattering amplitudes.

    hep-phgr-qchep-thPRD(2024)·3 citations
43. 43*

    $CP$ asymmetries in $\tau \to K_S\pi {\nu }_{\tau }$ decays

    Feng-Zhi Chen🇨🇳 · Xin-Qiang Li🇨🇳

    We present here the CP asymmetries in the decay rate and angular distributions of $\tau \to K_S\pi {\nu }_{\tau }$ decays in the Standard Model (SM) and beyond (BSM). The CP asymmetries in the SM are induced by the CP violation in $K^0-{\bar{K}}^0$ mixing. To investigate the BSM CP-violating (CPV) effects, a model-independent analysis is performed by using the low-energy effective field theory (LEFT) framework at $\mu =2$~GeV. If one further assumes the BSM physics to stem from above the electroweak scale, the LEFT shall then be matched onto the SM effective field theory (SMEFT), the operators of which contributing to $\tau \to K_S\pi {\nu }_{\tau }$ decays will also contribute to the neutron electric dipole moment (EDM) and $D^0-{\bar{D}}^0$ mixing. The stringent bounds from the latter suggest that no remarkable CPV effects can be observed in either the decay rate or the angular distributions. The prospects for future measurements of these observables are also mentioned.

    hep-phInt.J.Mod.Phys.A(2024)·1 citation
44. 44*

    Global analysis of fragmentation functions to charged hadrons with high-precision data from the LHC

    Jun Gao🇨🇳 · ChongYang Liu🇨🇳 · XiaoMin Shen🇨🇳 · Hongxi Xing🇨🇳 · Yuxiang Zhao🇨🇳

    Fragmentation functions (FFs) are essential non-perturbative QCD inputs for predicting hadron production cross sections in high energy scatterings. In this study, we present a joint determination of FFs for light charged hadrons through a global analysis at next-to-leading order (NLO) in QCD. Our analysis incorporates a wide range of precision measurements from the LHC, as well as data from electron-positron collisions and semi-inclusive deep inelastic scatterings. By including measurements of jet fragmentation at the LHC in our global analysis, we are able to impose strong constraints on the gluon FFs. A careful selection of hadron kinematics is applied to ensure the validity of factorization and perturbative calculations of QCD. In addition, we introduce several methodological advances in fitting, resulting in a flexible parametrization form and the inclusion of theoretical uncertainties from perturbative calculations. Our best-fit predictions show very good agreement with the global data, with ${\chi }^2/N_{pt}\sim 0.90$. We also generate a large number of Hessian error sets to estimate uncertainties and correlations of the extracted FFs. FFs to charged pions (kaons and protons) are well constrained for momentum fractions down to 0.01 (0.1). Total momentum of partons carried by light charged hadrons are determined precisely. Their values for $u$, $d$ quarks and gluon saturate at about 50\% for a lower cut of the momentum fraction of 0.01. Pulls from individual datasets and impact of various choices of the analysis are also studied in details. Additionally, we present an update of the FMNLO program used for calculating hadron production cross sections. Our FFs, including the error sets (denoted as NPC23), are publicly available in the form of LHAPDF6 grids.

    hep-phhep-exnucl-exnucl-thPRD(2024)·49 citations
45. 45*

    LVK constraints on PBHs from stochastic gravitational wave background searches

    Alba Romero-Rodríguez🇧🇪 · Sachiko Kuroyanagi🇪🇸

    Primordial black holes (PBHs) may have left an imprint in the form of a stochastic gravitational wave background (SGWB) throughout their evolution in the history of the Universe. This review highlights two types of SGWB: those generated by scalar curvature perturbations associated with PBH formation in the early Universe and those composed of ensembles of GWs emitted by PBH binaries. After describing detection methods and a brief introduction on Bayesian inference, we discuss current constraints imposed by LIGO-Virgo-KAGRA (LVK) observations through the non-detection of the SGWBs and discuss their physical implications.

    ↳ astro-ph.COgr-qchep-ph6 citations
46. 46*

    Lattice QCD Calculation of $x$-dependent Meson Distribution Amplitudes at Physical Pion Mass with Threshold Logarithm Resummation

    Ian Cloet🇺🇸 · Xiang Gao🇺🇸 · Swagato Mukherjee🇺🇸 · Sergey Syritsyn🇺🇸 · Nikhil Karthik🇺🇸 · Peter Petreczky🇺🇸 · Rui Zhang🇺🇸 · Yong Zhao🇺🇸

    We present a lattice quantum chromodynamics (QCD) calculation of the $x$-dependent pion and kaon distribution amplitudes (DA) in the framework of large momentum effective theory. This calculation is performed on a fine lattice of $a=0.076$ fm at physical pion mass, with the pion boosted to $1.8$ GeV and kaon boosted to $2.3$ GeV. We renormalize the matrix elements in the hybrid scheme and match to $\overline{\mathrm{MS}}$ with a subtraction of the leading renormalon in the Wilson-line mass. The perturbative matching is improved by resumming the large logarithms related to the small quark and gluon momenta in the soft-gluon limit. After resummation, we demonstrate that we are able to calculate a range of $x\in [x_0,1-x_0]$ with $x_0=0.25$ for pion and $x_0=0.2$ for kaon with theoretical systematic errors under control. The kaon DA is shown to be slighted skewed, and narrower than pion DA. Although the $x$-dependence cannot be direct calculated beyond these ranges, we estimate higher moments of the pion and kaon DAs by complementing our calculation with short-distance factorization.

    ↳ hep-lathep-exhep-phnucl-thPRD(2024)·27 citations
47. 47*

    Prospects for the detection of very-high-energy pulsars with LHAASO and SWGO

    Quan Hu🇨🇳 · Yi Zhang🇨🇳 · Kaikai Duan🇨🇳 · Houdun Zeng🇨🇳

    Pulsations from the Crab pulsar have been detected by the MAGIC telescopes at energies up to 1.5 TeV, and the pulsed emission from the Vela pulsar was detected by H.E.S.S., reaching tens of TeV. These discoveries, along with the proposed additional emission due to inverse Compton scattering at TeV energies, lead us to consider suitable candidates for detection with current and future extensive air show (EAS) experiments at very-high-energy (VHE; 0.1 $-$ 100 TeV) ranges. Leveraging energy spectrum data from pulsars as observed by Fermi and Imaging Atmospheric Cherenkov Telescopes (IACTs) and considering the sensitivities of both LHAASO and SWGO, this study evaluates their detectability and estimates the time required for their significant detection. Our results indicate that LHAASO could detect the Crab's pulsed signal within six years, while SWGO might detect Vela's signal within one year. Observations of the most energetic Fermi pulsars with EAS experiments will provide insight into the nature of VHE pulsar emissions, helping to clarify the primary characteristics of VHE pulsars.

    ↳ astro-ph.HEhep-phMNRAS(2024)·3 citations
48. 48*

    Even- and odd-parity stabilities of black holes in Einstein-Aether gravity

    Antonio De Felice🇯🇵 · Shinji Mukohyama🇯🇵 · Shinji Tsujikawa🇯🇵 · Anzhong Wang🇺🇸 · Chao Zhang🇨🇳

    In Einstein-Aether theories with a timelike unit vector field, we study the linear stability of static and spherically symmetric black holes against both even- and odd-parity perturbations. For this purpose, we formulate a gauge-invariant black hole perturbation theory in the background Aether-orthogonal frame where the spacelike property of hypersurfaces orthogonal to the timelike Aether field is always maintained even inside the metric horizon. Using a short-wavelength approximation with large radial and angular momenta, we show that, in general, there are three dynamical degrees of freedom arising from the even-parity sector besides two propagating degrees of freedom present in the odd-parity sector. The propagation speeds of even-parity perturbations and their no-ghost conditions coincide with those of tensor, vector, and scalar perturbations on the Minkowski background, while the odd sector contains tensor and vector modes with the same propagation speeds as those in the even-parity sector (and hence as those on the Minkowski background). Thus, the consistent study of black hole perturbations in the Aether-orthogonal frame on static and spherically symmetric backgrounds does not add new small-scale stability conditions to those known for the Minkowski background in the literature.

    ↳ gr-qcastro-ph.COhep-phhep-thJCAP(2024)·5 citations
49. 49*

    Landscape of QCD Vacuum

    George Savvidy🇬🇷

    We found new solutions of the sourceless Yang-Mills equation describing the superposition of chromomagnetic vortices of oppositely oriented magnetic fluxes. These gauge field configurations have constant energy densities and are separated by potential barriers forming a complicated landscape. It is suggested that the solutions describe the condensate of chromomagnetic vortices and represent a dual analog of the Cooper pairs condensate in a superconductor. In the presence of an Abelian field and in a particular limit the solutions reduce to the flat connections of zero energy density and are forming a complicated potential landscape of the QCD vacuum. A possible tunnelling transition between these superfluxon flat configurations and the flat configurations with non-vanishing Chern-Pontryagin index will wash out the CP violating $\theta$ angle to zero, dynamically restoring CP symmetry.

    ↳ hep-thhep-lathep-phPLB(2025)·3 citations
50. 50*

    Evolution and detection of vector superradiant instabilities

    Yin-Da Guo🇨🇳 · Nayun Jia🇨🇳 · Shou-Shan Bao🇨🇳 · Hong Zhang🇨🇳 · Xin Zhang🇨🇳

    Ultralight vectors can extract energy and angular momentum from a Kerr black hole (BH) due to superradiant instability, resulting in the formation of a BH-condensate system. In this work, we carefully investigate the evolution of this system numerically with multiple superradiant modes. Simple formulas are obtained to estimate important timescales, maximum masses of different modes, as well as the BH mass and spin at various times. Due to the coexistence of modes with small frequency differences, the BH-condensate system emits gravitational waves with a unique beat signature, which could be directly observed by current and projected interferometers. Besides, the current BH spin-mass data from the binary BH merger events already exclude the vector mass in the range $5\times 10^{-15}\mathrm{eV}<\mu <9\times 10^{-12}\mathrm{eV}$.

    ↳ gr-qchep-phPRD(2024)·9 citations
51. 51*

    Magnetic Polarisability of Octet Baryons via Lattice QCD

    Thomas Kabelitz (1) · Ryan Bignell (2) · Waseem Kamleh (1) · Derek Leinweber (1) ((1) University of Adelaide · (2) Trinity College)

    Drawing on recent advances in lattice-QCD background-field techniques, the magnetic polarisability of octet baryons is calculated from the first principles of QCD. The results are presented in the context of new constituent quark-model calculations providing a framework for understanding the lattice results and a direct comparison with simulation results at unphysical quark masses. Using smeared quark sources, low-lying Laplacian eigenmode projection and final-state Landau mode projection, considerable attention is devoted to ensuring single-state isolation in the lattice correlation functions. We also introduce new weighting methods to reduce the sensitivity to correlation-function fits, averaging over many fits based on merit drawn from the full correlated ${\chi }^2$ of the fits. The techniques are implemented on the $32^3\times 64$, 2+1-flavour dynamical-fermion lattices provided by the PACS-CS collaboration following the introduction of uniform magnetic fields quantised to the lowest nontrivial values available. After some fine tuning of the constituent quark model parameters, we find the model captures the patterns observed in the lattice QCD results very well, providing important insights into the physics underpinning the magnetic polarisabilities. Finally, comparison with the most recent results from experiment proceeds through an effective field theory formalism which incorporates estimates of finite-volume corrections and small electro-quenching corrections as the results are brought to the physical point. We find excellent agreement with experiment where available, including the proton and neutron polarisabilities.

    ↳ hep-lathep-phnucl-thPRD(2024)·4 citations
52. 52*

    Combining pre- and post-recombination new physics to address cosmological tensions: case study with varying electron mass and sign-switching cosmological constant

    Yo Toda🇯🇵 · William Giarè🇬🇧 · Emre Özülker🇹🇷 · Eleonora Di Valentino🇬🇧 · Sunny Vagnozzi🇮🇹

    It has recently been argued that the Hubble tension may call for a combination of both pre- and post-recombination new physics. Motivated by these considerations, we provide one of the first concrete case studies aimed at constructing such a viable combination. We consider models that have individually worked best on either end of recombination so far: a spatially uniform time-varying electron mass leading to earlier recombination (also adding non-zero spatial curvature), and a sign-switching cosmological constant inducing an AdS-to-dS transition within the ${\Lambda }_{\mathrm{s}}$CDM model. When confronted against Cosmic Microwave Background (CMB), Baryon Acoustic Oscillations, and Type Ia Supernovae data, we show that no combination of these ingredients can successfully solve the Hubble tension. We find that the matter density parameter ${\Omega }_m$ plays a critical role, driving important physical scales in opposite directions: the AdS-to-dS transition requires a larger ${\Omega }_m$ to maintain the CMB acoustic scale fixed, whereas the varying electron mass requires a smaller ${\Omega }_m$ to maintain the redshift of matter-radiation equality fixed. Despite the overall failure, we use our results to draw general model-building lessons, highlighting the importance of assessing tension-solving directions in the parameter space of new physics parameters and how these correlate with shifts in other standard parameters, while underscoring the crucial role of ${\Omega }_m$ in this sense.

    ↳ astro-ph.COgr-qchep-phhep-thPhys.Dark Univ.(2024)·81 citations
53. 53*

    Kurtosis consistency relation in large-scale structure as a probe of gravity theories

    Sora Yamashita🇯🇵 · Takahiko Matsubara🇯🇵 · Tomo Takahashi🇯🇵 · Daisuke Yamauchi🇯🇵

    Various gravity theories beyond general relativity have been rigorously investigated in the literature such as Horndeski and degenerate higher-order scalar-tensor (DHOST) theories. In general, numerous model parameters are involved in such theories, which should be constrained to test the theories with experiments and observations. We construct the kurtosis consistency relations, calculated based on matter density fluctuations, in which the information of gravity theories is encoded. We derive two independent consistency relations that should hold in the framework of the DHOST theories and argue that such consistency relations would be useful for testing gravity theories.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2024)·2 citations
54. 54*

    A String Theoretic Derivation of Gibbons-Hawking Entropy

    Gia Dvali🇩🇪

    We describe an attempt of string theoretic derivation of the Gibbons-Hawking entropy. Despite not admitting a de Sitter vacuum, the string theory, by the power of open-close correspondence, captures the Gibbons-Hawking entropy as the entropy of Chan-Paton species on a de Sitter-like state obtained via $D$-branes. Moreover, this derivation sheds a new light at the origin of the area-form, since the equality takes place for a critical 't Hooft coupling for which the species entropy of open strings saturates the area-law unitarity bound.

    ↳ hep-thgr-qchep-phGen.Rel.Grav.(2025)·7 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.