Tue·Apr 9, 2024Tuesday·April 9, 2024

1. 01*

   Detecting Ultralight Dark Matter Gravitationally with Laser Interferometers in Space

   Jiang-Chuan Yu🇨🇳 · Yan Cao🇨🇳 · Yong Tang🇨🇳 · Yue-Liang Wu🇨🇳

   Ultralight dark matter (ULDM) is one of the leading well-motivated dark matter candidates, predicted in many theories beyond the standard model of particle physics and cosmology. There have been increasing interests in searching for ULDM in physical and astronomical experiments, mostly assuming there are additional interactions other than gravity between ULDM and normal matter. Here we demonstrate that even if ULDM has only gravitational interaction, it shall induce gravitational perturbations in solar system that may be large enough to cause detectable signals in future gravitational-wave (GW) laser interferometers in space. We investigate the sensitivities of Michelson time-delay interferometer to ULDM of various spins, and show vector ULDM with mass $m\lesssim 10^{-18}$eV can be probed by space-based GW detectors aiming at $\mu$Hz frequencies. Our findings exhibit that GW detectors may directly probe ULDM in some mass ranges that otherwise are challenging to examine.

   hep-phastro-ph.COgr-qcPRD(2024)·22 citations
2. 02*

   Invisible and Semi-invisible Decays of Bottom Baryons

   Yong Zheng🇨🇳 · Jian-Nan Ding🇨🇳 · Dong-Hao Li🇨🇳 · Lei-Yi Li🇨🇳 · Cai-Dian Lü🇨🇳 · Fu-Sheng Yu🇨🇳

   The similar densities of dark matter and baryons in the universe imply that they might arise from the same ultraviolet model. The B-Mesogenesis, which assumes dark matter is charged under the baryon number, attempts to simultaneously explain the origin of baryon asymmetry and dark matter in the universe. In particular, the B-Mesogenesis might induce bottom-baryon decays into invisible or semi-invisible final states, which provide a distinctive signal for probing this scenario. In this work, we systematically study the invisible decays of bottom baryons into dark matters, and semi-invisible decays of bottom baryons into a meson or a photon together with a dark matter particle. In particular, the fully invisible decay can explore the stable particles in B-Mesogenesis. Some QCD-based frameworks are used to calculate the hadronic matrix elements under the B-Mesogenesis model. We estimate the constraints on the Wilson coefficients or the product of some new physics couplings with the Wilson coefficients by the semi-invisible and invisible decays of bottom baryons at future colliders.

   hep-phhep-exCPC(2024)·5 citations
3. 03*

   Parameters of the tensor tetraquark $bb\overline{c}\overline{c}$

   S. S. Agaev🇦🇿 · K. Azizi🇮🇷 · H. Sundu🇹🇷

   The mass and width of the tensor tetraquark $T=bb\overline{c}\overline{c}$ with spin-parity $J^{\mathrm{P}}=2^{+}$ are calculated in the context of the QCD sum rule method. The tetraquark $T$ is modeled as a diquark-antidiquark state built of components $b^{T}C{\gamma }_{\mu }b$ and $\overline{c}{\gamma }_{\nu }C{\overline{c}}^T$ with $C$ being the charge conjugation matrix. The mass $m=(12.795\pm 0.095)\mathrm{GeV}$ of the exotic tensor meson $T$ is found by means of the two-point sum rule approach. Its full width $\Gamma$ is evaluated by considering processes $T\to B_c^{-}{B}_c^{-}$, $B_c^{-}{B}_c^{\ast -}$, and $B_c^{\ast -}{B}_c^{\ast -}$. Partial widths of these decays are computed by means of the three-point sum rule approach which is used to determine the strong couplings at relevant tetraquark-meson-meson vertices. Predictions obtained for the width ${\Gamma }_{\mathrm{T}}=55.5_{-9.9}^{+10.6}\mathrm{MeV}$, as well as the mass of the tetraquark $T$ can be useful in investigations of fully heavy four-quark mesons.

   hep-phhep-exhep-latPLB(2024)·11 citations
4. 04*

   Boosted four-top production at the LHC : a window to Randall-Sundrum or extended color symmetry

   Debajyoti Choudhury🇮🇳 · Kuldeep Deka🇦🇪 · Lalit Kumar Saini🇮🇳

   Scenarios seeking to address the issue of electroweak symmetry breaking often have heavy colored gauge bosons coupling preferentially to the top quark. Considering the bulk Randall-Sundrum as a typical example, we consider the prospects of the first Kaluza-Klein mode ($G^{(1)}$) of the gluon being produced at the LHC in association with a $t\bar{t}$ pair. The enhanced coupling not only dictates that the dominant decay mode would be to a $t\bar{t}$ pair, but also to a very large $G^{(1)}$ width, necessitating the use of a renormalised $G^{(1)}$ propagator. This, alongwith the presence of large backgrounds (specially $t\bar{t}jj$), renders a conventional cut-based analysis ineffective, yielding only marginal significances of only around 2$\sigma$. The use of Machine Learning (ML) techniques alleviates this problem to a great extent. In particular, the use of Artificial Neural Networks helps us identify the most discriminating observables, thereby allowing a significance in excess of 4$\sigma$ for $G^{(1)}$ masses of $\sim$ 4 TeV.

   hep-phhep-thPRD(2024)·5 citations
5. 05*

   Quantum mechanical aspects of coherent photoproduction: the limits of coherence, and multiple vector mesons

   Spencer R. Klein🇺🇸

   Quantum mechanics is central to coherent photoproduction in ultra-peripheral collisions (UPCs). This writeup will discuss some surprising aspects of UPCs that stem from these quantum mechanical roots. The Good-Walker (GW) paradigm, which connects coherent photoproduction with the target nucleus remaining in its ground state. This contrasts with a semi-classical picture, where coherence depends on the positions of the individual nucleons and the momentum transfer. Unlike the GW approach, the semiclassical picture is consistent with the observed data on coherent photoproduction with nuclear breakup, and with coherent photoproduction in peripheral collisions. The semiclassical approach allows for a wider variety of coherent UPC reactions, such as coherent photoproduction of charged mesons, including some non $q\overline{q}$ exotica. Quantum mechanics is also key to the coherent photoproduction of multiple vector mesons by the interactions of a single ion pair. The vector mesons share a common impact parameter, and so can exhibit richer interference patterns than single mesons. At forward rapidities, the cross sections to produce multiple identical vector mesons are enhanced due to superradiance. With enough statistics, multi-meson events may provide an opportunity to observe stimulated decays.}

   hep-phnucl-exnucl-thquant-phPhys.Proc.UPC(2024)·3 citations
6. 06*

   On Capped Higgs Positivity Cone

   Dong-Yu Hong · Zhuo-Hui Wang🇨🇳 · Shuang-Yong Zhou🇨🇳

   The Wilson coefficients of the Standard Model Effective Field Theory are subject to a series of positivity bounds. It has been shown that, while the positivity part of the UV partial wave unitarity leads to the Wilson coefficients living in a convex cone, further including the non-positivity part caps the cone from above. For the Higgs scattering, a capped positivity cone have been obtained using a simplified, linear unitarity conditions and without utilizing the full internal symmetries of the Higgs scattering. Here we further implement the stronger nonlinear unitarity conditions from the UV, which generically gives rise to better bounds. We show that, for the Higgs case in particular, while the nonlinear unitarity conditions per se do not enhance the bounds, the fuller use of the internal symmetries do shrink the capped positivity cone significantly.

   hep-phhep-th14 citations
7. 07*

   Branching ratios and CP asymmetries of the quasi-two-body decays $B_c\to K_0^{\ast }(1430,1950)D_{(s)}\to K\pi D_{(s)}$ in the PQCD approach

   Zhi-Qing Zhang🇨🇳 · Zi-Yu Zhang🇨🇳 · Ming-Xuan Xie🇨🇳 · Ming-Yang Li🇨🇳 · Hong-Xia Guo🇨🇳

   In this paper, we investigate the quasi-two-body decays $B_c\to K_0^{\ast }(1430,1950)D_{(s)}\to K\pi D_{(s)}$ within the perterbative QCD (PQCD) framework. The S-wave two-meson distribution amplitudes (DAs) are introduced to describe the final state interactions of the $K\pi$ pair, which involve the time-like form factors and the Gegenbauer polynomials. In the calculations, we adopt two kinds of parameterization schemes to describe the time-like form factors: One is the relativistic Breit-Wigner (RBW) formula, which is usually more siutable for the narrow resonances, and the other is the LASS line shape proposed by the LASS Collaboration, which includes both the resonant and nonresonant components. We find that the branching ratios and the direct CP violations for the decays $B_c\to K_0^{\ast }(1430)D_{(s)}$ obtained from those of the quasi-two-body decays $B_c\to K_0^{\ast }(1430)D_{(s)}\to K\pi D_{(s)}$ under the narrow width approximation (NWA) can be consistent well with the previous PQCD results calculated in the two-body framework by assuming that $K_0^{\ast }(1430)$ being the lowest lying $\bar{q}s$ state, which is so-called scenario II (SII). We conclude that the LASS parameterization is more siutable to describe the $K_0^{\ast }(1430)$ than the RBW formula, and the nonresonant components play an important role in the branching ratios of the decays $B_c\to K_0^{\ast }(1430)D_{(s)}\to K\pi D_{(s)}$. In view of the large difference between the decay width measurements for the $K_0^{\ast }(1950)$ given by BaBar and LASS collaborations, we calculate the branching ratios and the CP violations for the quasi-two-body decays $B_c\to K_0^{\ast }(1950)D_{(s)}\to K\pi D_{(s)}$ by using two values, ${\Gamma }_{K_0^{\ast }(1950)}=0.100\pm 0.04$ GeV and ${\Gamma }_{K_0^{\ast }(1950)}=0.201\pm 0.034$ GeV, besides the two kinds of parameterizations for the resonance $K_0^{\ast }(1950)$.

   hep-phEPJC(2024)·2 citations
8. 08*

   Solving arbitrary one-loop reduction via generating function

   Tingfei Li🇨🇳 · Yuekai Song🇨🇳 · Liang Zhang🇨🇳

   Recently, the concept of generating function has been employed in one-loop reduction. For one-loop integrals encompassing arbitrary tensor ranks and higher-pole contributions, the generating function can be decomposed into a tensor part and a higher-pole part. While the tensor component has been thoroughly addressed in recent studies, there remains a lack of satisfactory investigations regarding the higher-pole part. In this work, we completely solve the problem. We first establish the partial differential equations governing the higher-pole generating function. Based on these equations, we derive an integration recursion relation and solve it iteratively. This approach enables us to explore the analytical structure of higher-pole reduction and provides a valuable tool for generating reduction coefficients efficiently.

   hep-phEPJC(2025)·8 citations
9. 09*

   Dark photon emission in elastic proton bremsstrahlung

   Ekaterina Kriukova🇷🇺

   We study the production of dark photons with masses in range 0.4-1.5\,GeV in elastic proton bremsstrahlung. In contrast to the known approaches to calculating the bremsstrahlung cross section, we consider the non-zero momentum transfer between protons. The numerical estimates show that the refined result agrees well with the generalized Weizsacker-Williams approximation, although it significantly differs from the result obtained by Blumlein and Brunner which is widely used in proton beam-dump phenomenology.

   hep-phPoS(2024)·3 citations
10. 10*

    Helicity-dependent parton distribution functions at next-to-next-to-leading order accuracy from inclusive and semi-inclusive deep-inelastic scattering data

    MAP (Multi-dimensional Analyses of Partonic distributions) Collaboration: Valerio Bertone🇫🇷 · Amedeo Chiefa🇬🇧 · Emanuele R. Nocera🇮🇹

    We present MAPPDFpol1.0, a new determination of the helicity-dependent parton distribution functions (PDFs) of the proton from a set of longitudinally polarised inclusive and semi-inclusive deep-inelastic scattering data. The determination includes, for the first time, next-to-next-to-leading order QCD corrections to both processes, and is carried out in a framework that combines a neural-network parametrisation of PDFs with a Monte Carlo representation of their uncertainties. We discuss the quality of the determination, in particular its dependence on higher-order corrections, on the choice of data set, and on theoretical constraints.

    hep-phhep-exPLB(2025)·40 citations
11. 11*

    Constraints on the $X17$ boson from IceCube searches for non-standard interactions of neutrinos

    Rikard Enberg🇸🇪 · Yaşar Hiçyılmaz🇹🇷 · Stefano Moretti🇬🇧 · Carlos Pérez de los Heros🇸🇪 · Harri Waltari🇸🇪

    We explain the ATOMKI anomaly with a very light $Z^{\prime }$ state that features non-anomalous and non-flavour-universal vector and axial-vector couplings to all leptons. This $Z^{\prime }$ comes from a theoretical framework with a spontaneously broken $U(1{)}^{\prime }$ symmetry in addition to the Standard Model gauge group and is compliant with current measurements of the anomalous magnetic moments of the electron and the muon as well as beam dump experiments. The lepton flavour structure of this model allows for $Z^{\prime }$ couplings to all light neutrinos, suggesting the possibility of $Z^{\prime }$-mediated Non-Standard Interactions (NSIs) of neutrinos in matter, so that measurements of the strength parameters of the NSIs can constrain the value of the couplings. We use experimental constraints on NSIs of neutrinos using older TEXONO data and newer IceCube data. The IceCube data, in particular, strongly constrain the flavour universality of the leptonic vector current. The constraints enable us to define the region of parameter space of this theoretical scenario that can be pursued in further phenomenological analyses.

    hep-phJHEP(2025)·5 citations
12. 12*

    Polarization analysis of two baryons with various spin combinations produced in electron-positron annihilation

    Zhe Zhang🇨🇳 · Rong-Gang Ping🇨🇳 · Tianbo Liu🇨🇳 · Jiao Jiao Song🇨🇳 · Weihua Yang🇨🇳 · Ya-jin Zhou🇨🇳

    We developed a method to analyze the polarization correlations of two baryons $B_1{\bar{B}}_2$ with various spin combinations in the annihilation process. We established spin density matrices for arbitrary spins in standard and Cartesian forms, and demonstrated their application in the helicity formalism. This paper provides parametrization schemes for the helicity amplitudes and details the analysis of two baryons with spin combinations of (1/2, 1/2), (1/2, 3/2), and (1/2, 5/2). We also illustrated methods for determining the spin and parity of the excited baryon ${\bar{\Xi }}^{\ast +}$ using the $e^{+}{e}^{-}\to {\gamma }^{\ast }/\psi \to {\Xi }^{-}{\bar{\Xi }}^{\ast +}$ process as an example. Our research offers broad opportunities for exploring the baryon spectrum and transition form factors in electron-positron annihilation.

    hep-phPRD(2024)·11 citations
13. 13*

    Five-body $D\to V$ Semileptonic Decays

    Yechun Yu · Han Zhang · Bai-Cian Ke · Yao Yu · Zhuang Xiong · Jia-Wei Zhang

    Our main objective is to derive the decay rate for the semileptonic decays $D\to V{\ell }^{+}{\nu }_{\ell }(\ell =e,\mu )$, where $V$ represents a vector particle. In these decays, the vector particle $V$ decays into three pseudo-scalar particles. To accomplish this, we evaluate the phase-space factor for the five-body decay with a set of eight independent variables which uniquely define a point in the phase space. We further conduct a detailed investigation of the $D\to \omega {\ell }^{+}{\nu }_{\ell }$, where $\omega$ subsequently decays into ${\pi }^{+}{\pi }^{-}{\pi }^0$, within the Standard Model and in a general effective field theory description of the weak interactions at low energies. The outcomes of this study have potential applications in the measurement of $D\to \omega$ form factors. These measurements can be performed using data obtained from BESIII.

    hep-phPRD(2024)·1 citation
14. 14*

    Two-photon production of $f_0$ and $a_0$ resonances as hadronic molecules composed of two vector mesons

    Li-Ke Yang (1 and 2)🇨🇳 · Zheng-Li Wang (2)🇨🇳 · Jia-Jun Wu (2)🇨🇳 · Bing-Song Zou (3, 1, 2) ((1) CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, China, (2) School of Physics, University of Chinese Academy of Sciences (UCAS), Beijing, China, (3) Department of Physics, Tsinghua University, Beijing, China)🇨🇳

    Ascribed as $\rho \rho$ and $K^{\ast }{\bar{K}}^{\ast }$ molecular states, respectively, iso-scalar $f_0(1500)$ and $f_0(1710)$ states are expected to have iso-vector partners, potentially identified as $a_0(1450)$ and $a_0(1710)$. The predicted dominant decay modes for these two $a_0$ resonances are $a_0(1450)\to \omega \pi \pi$ and $a_0(1710)\to \omega \pi \pi ,\varphi \pi \pi$. We estimate cross sections for two-photon production of these four resonances within the hadronic molecular picture, and demonstrate that SuperKEKB's luminosity is sufficient for their observation and more precise parameter measurements.

    hep-phPRD(2024)·2 citations
15. 15*

    Dark Matter-Induced Low-Mass Gap Black Hole Echoing LVK Observations

    Shuailiang Ge🇨🇳 · Yuxin Liu🇨🇳 · Jing Shu🇨🇳 · Yue Zhao🇺🇸

    The recent detection of gravitational waves from a binary merger involving a potential low-mass gap black hole (LMBH) by LIGO-Virgo-KAGRA (LVK) Collaboration motivates investigations into mechanisms beyond conventional stellar evolution theories to account for their existence. We study a mechanism in which dark matter (DM), through its capture and accumulation inside main sequence stars, induces the formation of black holes within the mass range of $[3,5]M_{\odot }$. We examine the distribution of these LMBHs as a function of galaxy halo mass, particularly when paired with neutron stars. This gives a distinct signature that can be tested with future gravitational wave observations. We find that a viable portion of the DM parameter space predicts a merger rate of such binaries consistent with LVK observations.

    hep-phastro-ph.HEJCAP(2026)·3 citations
16. 16*

    Lightcone and quasi distribution amplitudes for light octet and decuplet baryons

    Chao Han (1)🇨🇳 · Wei Wang (1 and 2)🇨🇳 · Jun Zeng (1)🇨🇳 · Jia-Lu Zhang (1) ((1) NPAC, Key Laboratory for Particle Astrophysics and Cosmology (MOE), Shanghai Key Laboratory for Particle Physics and Cosmology, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, China, (2) Southern Center for Nuclear-Science Theory (SCNT), Institute of Modern Physics, Chinese Academy of Sciences, Huizhou, Guangdong Province, China)🇨🇳

    We present a comprehensive investigation of leading-twist lightcone distribution amplitudes (LCDAs) and quasi distribution amplitudes (quasi-DAs) for light octet and decuplet baryons within large momentum effective theory. In LaMET, LCDAs can be factorized in terms of a hard kernel and quasi-DAs that are defined as spatial correlators and calculable on Lattice QCD. To renormalize quasi-DAs and eliminate the singular terms $\ln ({\mu }^2{z}_i^2{)}^{\prime }s$ in them, which undermine the efficacy in perturbative expansion, we adopt a hybrid renormalization scheme that combines the self-renormalization and ratio scheme. Through self-renormalization, we eliminate UV divergences and linear divergences at large spatial separations in quasi distribution amplitudes without introducing additional nonperturbative effects. By taking a ratio with respect to the zero-momentum matrix element, we effectively remove UV divergences at small spatial separations. Under the hybrid renormalization scheme, we calculate the hard kernels up to one-loop accuracy. It turns out that only four different hard kernels are needed for all leading-twist LCDAs of octet and decuplet baryons. These results are crucial for the lattice-based exploration of the LCDAs of a light baryon from the first principle of QCD.

    hep-phJHEP(2024)·28 citations
17. 17*

    On the cosmological abundance of magnetic monopoles

    Chen Zhang🇺🇸 · Shi-Hao Zhang🇺🇸 · Bowen Fu🇺🇸 · Jing-Fei Zhang🇺🇸 · Xin Zhang🇨🇳

    We demonstrate that Debye shielding cannot be employed to constrain the cosmological abundance of magnetic monopoles, contrary to what is stated in the previous literature. Current model-independent bounds on the monopole abundance are then revisited for unit Dirac magnetic charge. We find that the Andromeda Parker bound can be employed to set an upper limit on the monopole flux at the level of $F_M\lesssim 5.3\times 10^{-19}{\text{cm}}^{-2}{\text{s}}^{-1}{\text{sr}}^{-1}$ for a monopole mass $10^{13}\text{GeV}/c^2\lesssim m\lesssim 10^{16}\text{GeV}/c^2$, which is more stringent than the MACRO direct search limit by two orders of magnitude. This translates into stringent constraints on the monopole density parameter ${\Omega }_M$ at the level of $10^{-7}-10^{-4}$ depending on the mass. For larger monopole masses the scenarios in which magnetic monopoles account for all or the majority of dark matter are disfavored.

    hep-phastro-ph.COastro-ph.GAastro-ph.HE+1JHEP(2024)·12 citations
18. 18*

    Influence of the chiral magnetic effect on particle-pair elliptic anisotropy

    Han-Sheng Li🇺🇸 · Yicheng Feng🇺🇸 · Fuqiang Wang🇨🇳

    Chiral Magnetic Effect (CME) is a phenomenon in which electric charge is separated by a strong magnetic field from local domains of chirality imbalance in quantum chromodynamics. The CME-sensitive, azimuthal correlator difference $\Delta \gamma$ between opposite-sign (OS) and same-sign (SS) charged hadron pairs is contaminated by a major physics background proportional to the particle elliptic anisotropy ($v_2$). The CME signal, on the other hand, contributes to the difference in the pair elliptic anisotropies between OS and SS pairs ($\Delta v_{2,\mathrm{pair}}$). We investigate $\Delta v_{2,\mathrm{pair}}$ and found its sensitivity to CME to be similar to that of the $\Delta \gamma$ observable.

    hep-phnucl-exnucl-thPRC(2025)·6 citations
19. 19*

    Quasiparton distributions in massive QED2: Toward quantum computation

    Sebastian Grieninger🇺🇸 · Kazuki Ikeda🇺🇸 · Ismail Zahed🇺🇸

    We analyze the quasi-parton distributions of the lightest ${\eta }^{\prime }$ meson in massive two-dimensional Quantum electrodynamics (QED2) by performing a digital quantum simulation on a classical computer (exact diagonalization). The Hamiltonian and boost operators are mapped onto spin qubits in a spatial lattice with open boundary conditions. The lowest excited state in the exact diagonalization is shown to interpolate continuously between an anomalous ${\eta }^{\prime }$ state at strong coupling,and a non-anomalous heavy meson at weak coupling, with a cusp at the critical point. The boosted ${\eta }^{\prime }$ state follows relativistic kinematics but with large deviations in the luminal limit. The spatial quasi-parton distribution function and amplitude for the ${\eta }^{\prime }$ state are computed numerically for increasing rapidity both at strong and weak coupling, and compared to the exact light front results. The numerical results from the boosted form of the spatial parton distributions, compare fairly with the inverse Fourier transformation of the luminal parton distributions, derived in the lowest Fock space approximation. Our analysis points out some of the limitations facing the current lattice program for the parton distributions.

    hep-phhep-lathep-thnucl-th+1PRD(2024)·27 citations
20. 20*

    Analysis of $B_s^0\to X(3872)[\psi (2S)]{\pi }^{+}{\pi }^{-}(K^{+}{K}^{-})$ decays

    Hao-Nan Wang🇨🇳 · Li-Sheng Geng🇨🇳 · Gang Li🇨🇳 · Ju-Jun Xie🇨🇳

    We have phenomenologically investigated the decays $B_s^0\to X(3872){\pi }^{+}{\pi }^{-}(K^{+}{K}^{-})$ and $B_s^0\to \psi (2S){\pi }^{+}{\pi }^{-}(K^{+}{K}^{-})$. In our analysis, the scalar meson $f_0(980)$ is formed through the final state interactions of coupled channels $\pi \pi$ and $K\bar{K}$. Our findings indicate that the ${\pi }^{+}{\pi }^{-}$ invariant mass distribution of the $B_s^0\to \psi (2S){\pi }^{+}{\pi }^{-}$ decay can be accurately reproduced. Furthermore, we have explored the ${\pi }^{+}{\pi }^{-}(K^{+}{K}^{-})$ invariant mass distribution of the $B_s^0\to X(3872){\pi }^{+}{\pi }^{-}(K^{+}{K}^{-})$ decay, accounting for the different production mechanisms between $X(3872)$ and $\psi (2S)$, up to a global factor. It is found that the production rates for $X(3872)$ and $\psi (2S)$ are much different, which indicates that the structure of $X(3872)$ is more complicated than the $\psi (2S)$, which is a conventional $c\bar{c}$ state. Additionally, we have considered the contributions from $f_0(1500)$ to ${\pi }^{+}{\pi }^{-}$ and the $\varphi$ meson to $K^{+}{K}^{-}$ in our analysis. Utilizing the model parameters, we have calculated the branching fraction of $B_s^0\to X(3872)K^{+}{K}^{-}$, and anticipate that the findings of our study can be experimentally tested in the future.

    hep-phhep-exnucl-exnucl-thPRD(2024)·3 citations
21. 21*

    T-odd Parton Distribution Functions and Azimuthal Anisotropy at High Transverse Momentum in $p$-$p$ and $p$-$A$ Collisions

    Ismail Soudi🇺🇸 · Abhijit Majumder🇺🇸

    Various azimuthal anisotropies ($v_1,v_2,v_3,v_4$), at high transverse momentum (high-$p_T$), are shown to arise from the asymmetric scattering of transverse polarized quarks and gluons, arising from unpolarized nucleons (the Boer-Mulders' effect) and resulting in unpolarized hadrons (the Collins effect). Combined with the asymmetric scattering of partons from polarization independent but transverse momentum dependent (TMD) distributions, we obtain a possible mechanism to understand the azimuthal anisotropy of hadrons at large transverse momentum observed in $p$-$p$ collisions. Constraining the ratio of polarization dependent TMD distributions to polarization independent distributions by comparing with the data from $p$-$p$ collisions, we find that scaling the acquired transverse momentum of the initial state partons from the proton, due to prescattering before the hard interaction, with the length of the nucleus ($k_{\perp }^2\propto A^{1/3}$), straightforwardly yields the azimuthal anisotropy at high $p_T$ in $p$-$A$ collisions.

    hep-phnucl-thPRC(2025)·8 citations
22. 22*

    Reduction of (pseudo-)Critical Temperatures of Chiral Restoration and Deconfinement Phase Transitions in a Magnetized PNJL Model

    Shijun Mao🇨🇳

    We investigate the chiral restoration and deconfinement phase transitions under external magnetic field in frame of a Pauli-Villars regularized PNJL model. A running Polyakov loop scale parameter $T_0(eB)$ is introduced to mimic the reaction of the gluon sector to the presence of magnetic fields. It is found that a decreasing $T_0(eB)$ with magnetic fields can realize the inverse magnetic catalysis phenomena of chiral condensates of $u$ and $d$ quarks, increase of Polyakov loop and the reduction of (pseudo-)critical temperatures of chiral restoration and deconfinement phase transitions.

    hep-phnucl-thPRD(2024)·9 citations
23. 23*

    $c\bar{c}$ and $b\bar{b}$ suppression in Glasma

    Pooja🇮🇳 · Mohammad Yousuf Jamal🇮🇳 · Partha Pratim Bhaduri🇮🇳 · Marco Ruggieri🇮🇹 · Santosh K. Das🇮🇳

    This study investigates the evolution and dissociation dynamics of $c\bar{c}$ and $b\bar{b}$ pairs within the pre-equilibrium, gluon-dominated stage of high energy nuclear collisions. An attractive potential made of a perturbative Coulomb-like term and of a confining term is used to simulate the attractive strong force in the pairs. Besides, we implement the interaction of the pairs with the evolving Glasma fields by virtue of the Wong equations. The interaction with the classical color fields dominates the dynamics, causing an increase in pair separation and subsequent dissociation. The observed finite probability of dissociation for these states reveals the intricate interplay between QCD dynamics and the suppression of $c\bar{c}$ and $b\bar{b}$ states during the pre-equilibrium stage. The research highlights differences between $c\bar{c}$ and $b\bar{b}$ pairs, revealing the role of quark flavor in the dissociation process. Dissociation spectra analysis indicates a peak shift towards higher momentum, reflecting a slight energy gain by the pairs. This investigation provides valuable insights into the complex dynamics of $c\bar{c}$ and $b\bar{b}$ pairs in the Glasma, which may help in better interpretation of experimental results on further integration with subsequent phases of the created matter.

    hep-phnucl-thPRD(2024)·24 citations
24. 24*

    XYZ spectroscopy at electron-hadron facilities III: Semi-inclusive processes with vector exchanges

    Joint Physics Analysis Center Collaboration: D. Winney🇩🇪 · A. Pilloni🇮🇹 · R. J. Perry🇪🇸 · L. Bibrzycki🇵🇱 · C. Fernandez-Ramirez🇪🇸 · N. Hammoud🇵🇱 · V. Mathieu🇪🇸 · G. Montana🇺🇸 · A. Rodas🇺🇸 · V. Shastry🇺🇸 · W. A. Smith🇺🇸 · A. P. Szczepaniak🇺🇸

    Inclusive production processes will be important for the first observations of $XYZ$ states at new generation electron-hadron colliders, as they generally benefit from larger cross sections than their exclusive counterparts. We make predictions of semi-inclusive photoproduction of the ${\chi }_{c1}(1P)$ and $X(3872)$, whose peripheral production is assumed to be dominated by vector exchanges. We validate the applicability of Vector Meson Dominance in the axial-vector charmonium sector and calculate production rates at center-of-mass energies relevant for future experimental facilities. We find the semi-inclusive cross sections near threshold to be enhanced by a factor of $\sim 2-3$ compared to the exclusive reaction and well suited for a first observation in photoproduction.

    hep-phhep-exPRD(2024)·5 citations
25. 25*

    Strong decays of the vector tetraquark states with the masses about $4.5\mathrm{GeV}$ via the QCD sum rules

    Zhi-Gang Wang🇨🇳

    We suppose that there exist three vector hidden-charm tetraquark states with the $J^{PC}=1^{--}$ at the energy about $4.5\mathrm{GeV}$, and investigate the two-body strong decays systematically. We obtain thirty QCD sum rules for the hadronic coupling constants based on rigorous quark-hadron duality, then obtain the partial decay widths, therefore the total widths approximately, which are compatible with the experimental data of the $Y(4500)$ from the BESIII collaboration. The $Y(4500)$ may be one vector tetraquark state having three main Fock components, or consists of three different vector tetraquark states. We can search for the typical decays $Y\to \frac{{\bar{D}}_1^0{D}^0-{\bar{D}}^0{D}_1^0}{\sqrt{2}}$, $\frac{{\bar{D}}_1^{-}{D}^{+}-{\bar{D}}^{-}{D}_1^{+}}{\sqrt{2}}$, $\frac{{\bar{D}}_0^0{D}^{\ast 0}-{\bar{D}}^{\ast 0}{D}_0^0}{\sqrt{2}}$, $\frac{{\bar{D}}_0^{-}{D}^{\ast +}-{\bar{D}}^{\ast -}{D}_0^{+}}{\sqrt{2}}$, ${\eta }_c\omega$, $J/\psi \omega$ to diagnose the nature of the $Y(4500)$.

    hep-phNPB(2024)·9 citations
26. 26*

    Dark matter phenomenology and phase transition dynamics of the next to minimal composite Higgs model with dilaton

    Borui Zhang🇨🇳 · Zhao Zhang🇨🇳 · Chengfeng Cai🇨🇳 · Hong-Hao Zhang🇨🇳

    In this paper, we conduct a comprehensive study of the Next-to-Minimal Composite Higgs Model (NMCHM) extended with a dilaton field $\chi$ (denoted as NMCHM${}_{\chi }$). A pseudo-Nambu-Goldstone boson (pNGB) $\eta$, resulting from the SO(6)$\to$SO(5) breaking, serves as a dark matter (DM) candidate. The inclusion of the dilaton field is helpful for evading the stringent constraints from dark matter direct detection, as it allows for an accidental cancellation between the amplitudes of DM-nucleon scattering, an outcome of the mixing between the dilaton and Higgs fields. The presence of the dilaton field also enriches the phase transition patterns in the early universe. We identify two types of phase transitions: (i) a 1-step phase transition, where the chiral symmetry and electroweak symmetry breaking (EWSB) occur simultaneously, and (ii) a 2-step phase transition, where the chiral symmetry breaking transition takes place first, followed by a second phase transition corresponding to EWSB. Since the first-order phase transitions can be strong due to supercooling in our model, we also examine the stochastic background of gravitational waves generated by these phase transitions. We find that these gravitational waves hold promise for detection in future space-based gravitational wave experiments, such as LISA, Taiji, BBO, and DECIGO.

    hep-phastro-ph.HEPRD(2024)·3 citations
27. 27*

    Testing of Pythia modes to study identified particle production in high-multiplicity pp collisions at $\sqrt{\mathbf{s}}$ = 7 TeV

    Rabia Bashir🇵🇰 · Ramoona Shahzadi · M. U. Ashraf🇺🇸

    This study presents a comprehensive analysis of particle production in proton-proton ($pp$) collisions at $\sqrt{s}$ = 7 TeV using Pythia~8 event generator. We investigate the transverse momentum $p_T$ spectra of light charged hadrons (${\pi }^{\pm }$, $K^{\pm }$ and $p(\bar{p})$), their yield ratios (${\pi }^{-}/{\pi }^{+}$, $K^{-}/K^{+}$ and $\bar{p}/p$), and $p_T$-differential ratios ($(K^{+}+K^{-})/({\pi }^{+}+{\pi }^{-})$, $(\overline{p}+p)/({\pi }^{+}+{\pi }^{-})$) and mean transverse momentum ($⟨p_{\mathrm{T}}⟩$). Our analysis employs various Pythia~8 tunes (Simple, Vincia, and Dire) to explore the impact of different model configurations on particle production. We optimize a key parameter ($p_{\mathrm{T}}HatMin$) within each tune to achieve the best agreement between the simulated \ppt spectra and those measured by the CMS collaboration. Interestingly, we find that the optimal values for $p_{\mathrm{T}}HatMin$ differ between hadron species, potentially reflecting the influence of particle mass on production mechanisms. It is not possible to simultaneously and qualitatively describe both, the strangeness enhancement and collectivity in $pp$ collisions from \pythia~8. Further investigation such as final-state effects such as color ropes or junctions may require to explain these effects. These types of studies help us identify limitations in current models and refine their parameters to better explain experimental observations.

    hep-ph0 citations
28. 28*

    Rewording Theoretical Predictions at Colliders with Vacuum Amplitudes

    Selomit Ramírez-Uribe🇪🇸 · Prasanna K. Dhani🇪🇸 · German F.R. Sborlini🇪🇸 · Germán Rodrigo🇪🇸

    We propose multiloop vacuum amplitudes as the optimal building blocks for efficiently assembling theoretical predictions at high-energy colliders. This hypothesis is strongly supported by the manifestly causal properties of the loop-tree duality (LTD) representation of a vacuum amplitude. The vacuum amplitude, acting as a kernel, encodes all the final states contributing to a given scattering or decay process through residues in the on-shell energies of the internal propagators. It also naturally implements gauge invariance and the wave function renormalisation of the external legs. This methodological approach, dubbed LTD causal unitary, leads to a novel representation of differential cross sections and decay rates that is locally free of ultraviolet and infrared singularities at all orders in perturbation theory. Threshold singularities also match between different phase-space residues. Most notably, it allows us to conjecture for the first time the local functional form of initial-state collinear singularities. The fulfillment of all these properties provides a theoretical description of differential observables at colliders that is well defined in the four physical dimensions of the space-time.

    hep-phhep-exhep-thPRL(2024)·33 citations
29. 29*

    Vacuum amplitudes and time-like causal unitary in the loop-tree duality

    The LTD Collaboration · Selomit Ramírez-Uribe · Andrés E. Rentería-Olivo · David F. Rentería-Estrada · Jorge J. Martínez de Lejarza · Prasanna K. Dhani · Leandro Cieri · Roger J. Hernández-Pinto · German F. R. Sborlini · William J. Torres Bobadilla · Germán Rodrigo

    We present the first proof-of-concept application to decay processes at higher perturbative orders of LTD causal unitary, a novel methodology that exploits the causal properties of vacuum amplitudes in the loop-tree duality (LTD) and is directly well-defined in the four physical dimensions of the space-time. The generation of loop- and tree-level contributions to the differential decay rates from a kernel multiloop vacuum amplitude is shown in detail, and explicit expressions are presented for selected processes that are suitable for a lightweight understanding of the method. Specifically, we provide a clear physical interpretation of the local cancellation of soft, collinear and threshold singularities, and of the local renormalisation of ultraviolet singularities. The presentation is illustrated with numerical results that showcase the advantages of the method.

    hep-phhep-exhep-thJHEP(2025)·31 citations
30. 30*

    $(g-2{)}_{e,\mu }$ anomalies and decays $h,Z\to e_b{e}_a$ in 3-3-1 models with inverse seesaw neutrinos

    T.T. Hong🇻🇳 · L.T.T. Phuong🇻🇳 · T.Phong Nguyen🇻🇳 · N. H. T. Nha🇻🇳 · L. T. Hue🇻🇳

    The lepton flavor violating (LFV) decays $h,Z\to e_b{e}_a$, and $e_b\to e_a\gamma$ are discussed in a class of general 3-3-1 models adding heavy neutral leptons and singly charged Higgs bosons to accommodate experimental data of neutrino oscillation and $(g-2{)}_{e_a}$ anomalies of charged leptons through the inverse seesaw mechanism. We show that the models with the minimal number of inverse seesaw neutrinos cannot reach the $1\sigma$ range of $(g-2{)}_{\mu }$ data due to the experimental upper bounds on decay rates of $(\tau \to \mu \gamma )$ and $(\mu \to e\gamma )$. Features of LFV decays are presented in detail, focusing on the regions of parameter space satisfying the $1\sigma$ ranges of $(g-2{)}_{e,\mu }$ data.

    hep-phPRD(2024)·11 citations
31. 31*

    Complete Next-to-Leading Order QCD Corrections to $ZZ$ Production in Gluon Fusion

    Bakul Agarwal🇩🇪 · Stephen Jones🇬🇧 · Matthias Kerner🇩🇪 · Andreas von Manteuffel🇩🇪

    We calculate the complete NLO QCD corrections to loop-induced $gg\to ZZ$ production including full top-quark mass effects. The two-loop virtual corrections are obtained by combining analytic results for the massless, Higgs-mediated, and one-loop factorizable contributions with numerically computed amplitudes containing the top-quark mass. We show that the choice of subtraction scheme for the virtual contribution impacts the precision with which the virtual contribution must be evaluated in order to obtain sufficiently precise phenomenological predictions. For direct production through a massive top-quark loop, we observe that the relative NLO corrections are large. The direct massive and Higgs-mediated contributions individually increase relative to the massless production at high diboson invariant mass, but interfere destructively with each other. At the Large Hadron Collider, the NLO corrections to the gluon channel give a sizable contribution to the $pp\to ZZ+X$ cross-section at N${}^3$LO.

    hep-phPRL(2025)·17 citations
32. 32*

    Novel collider signatures in the type-I 2HDM+$a$ model

    Spyros Argyropoulos🇩🇪 · Ulrich Haisch🇩🇪 · Ilia Kalaitzidou🇩🇪

    The 2HDM+$a$ model is one of the main models used in the interpretations of dark matter searches at the LHC. So far, all the 2HDM+$a$ benchmarks considered by the ATLAS and CMS experiments are limited to a type-II Yukawa sector, in which the Higgs bosons $A$, $H$, and $H^{\pm }$ are all constrained to be mass-degenerate and heavier than around $600\mathrm{GeV}$. In this work, we present the first detailed study of 2HDM+$a$ models with a type-I Yukawa sector, which, for moderate values of $\tan \beta$, lift the constraints from flavour physics, allowing the extra Higgs bosons to be even lighter than the $125\mathrm{GeV}$ Higgs boson discovered at the LHC. We discuss several benchmarks where the $A$, $H$, and $H^{\pm }$ states are not necessarily mass-degenerate and the signatures that arise in these models, some of which have not yet been explored at the LHC. We present the dominant channels in the studied benchmarks and the expected sensitivity in Run 2 data using truth-level analyses and discuss potential improvements in the experimental searches for Run 3.

    hep-phhep-exJHEP(2024)·9 citations
33. 33*

    Pati-Salam models with $A_4$ modular symmetry

    Gui-Jun Ding🇨🇳 · Si-Yi Jiang🇨🇳 · Stephen F. King🇬🇧 · Jun-Nan Lu🇨🇳 · Bu-Yao Qu🇨🇳

    The flavor structure of quarks and leptons and quark-lepton unification are studied in the framework of Pati-Salam models with $A_4$ modular symmetry. The three generations of the left-handed and right-handed fermions are assigned to be triplet or singlets of $A_4$. The light neutrino masses are generated through the type-I seesaw mechanism. We perform a systematic classification of Pati-Salam models according to the transformations of matter fields under the $A_4$ modular symmetry, and the general form of the fermion mass matrix is given. We present four phenomenologically viable benchmark models which provide excellent descriptions of masses and flavor mixing of quarks and leptons, including neutrinos. In such models we find that the normal ordered neutrino mass spectrum is preferred over the inverted case, with neutrinoless double beta decay predicted to be too small to be observed by the next generation of experiments.

    hep-phJHEP(2024)·10 citations
34. 34*

    Perspectives from a cold antideuteron beam in the AD/ELENA facility

    Ruggero Caravita🇮🇹

    The perspectives opened by the development of a low-energy antideuteron beam are here reviewed: precision measurements of the antideuteron properties; formation and spectroscopic analysis of antideuteronic atoms and antideuterium; the pioneering synthesis of heavier anti-elements in particle traps and at low energies. Some practical aspects of generating a low-energy antideuteron beam in the existing AD/ELENA facility are discussed.

    hep-phnucl-exphysics.acc-phphysics.atom-ph6 citations
35. 35*

    Xiwu: A Basis Flexible and Learnable LLM for High Energy Physics

    Zhengde Zhang🇫🇷 · Yiyu Zhang🇨🇳 · Haodong Yao🇺🇸 · Jianwen Luo🇨🇳 · Rui Zhao · Bo Huang🇨🇳 · Jiameng Zhao🇨🇳 · Yipu Liao🇨🇳 · Ke Li🇺🇸 · Lina Zhao🇨🇳 · Jun Cao · Fazhi Qi🇨🇳 · Changzheng Yuan🇨🇳

    Large Language Models (LLMs) are undergoing a period of rapid updates and changes, with state-of-the-art (SOTA) model frequently being replaced. When applying LLMs to a specific scientific field, it's challenging to acquire unique domain knowledge while keeping the model itself advanced. To address this challenge, a sophisticated large language model system named as Xiwu has been developed, allowing you switch between the most advanced foundation models and quickly teach the model domain knowledge. In this work, we will report on the best practices for applying LLMs in the field of high-energy physics (HEP), including: a seed fission technology is proposed and some data collection and cleaning tools are developed to quickly obtain domain AI-Ready dataset; a just-in-time learning system is implemented based on the vector store technology; an on-the-fly fine-tuning system has been developed to facilitate rapid training under a specified foundation model. The results show that Xiwu can smoothly switch between foundation models such as LLaMA, Vicuna, ChatGLM and Grok-1. The trained Xiwu model is significantly outperformed the benchmark model on the HEP knowledge question-and-answering and code generation. This strategy significantly enhances the potential for growth of our model's performance, with the hope of surpassing GPT-4 as it evolves with the development of open-source models. This work provides a customized LLM for the field of HEP, while also offering references for applying LLM to other fields, the corresponding codes are available on Github.

    hep-phcs.AIcs.CLcs.LG+212 citations
36. 36*

    Global fit to $b\to c\tau \nu$ anomalies as of Spring 2024

    Syuhei Iguro🇩🇪 · Teppei Kitahara🇯🇵 · Ryoutaro Watanabe🇨🇳

    Recently, several new experimental results of the test of lepton flavor universality (LFU) in $B\to D^{(\ast )}$ semi-leptonic decays were announced: the first result of $R_D$ from the LHCb Run 1 data, the first results of $R_D$ and $R_{D^{\ast }}$ from the LHCb Run 2 data, and the first result of $R_{D^{\ast }}$ from the Belle II collaboration. Including these new data, a global analysis still prefers the violation of the LFU between the tau and light leptons. A new world average of the data from the BaBar, LHCb, Belle, and Belle II collaborations is $R_D=0.342\pm 0.026$ and $R_{D^{\ast }}=0.287\pm 0.012$. Including this new data, we update a circumstance of the $b\to c\tau \overline{\nu }$ measurements and their implications for new physics (NP). Incorporating recent developments for the $B\to D^{(\ast )}$ form factors in the Standard Model (SM), we observe a $4.4\sigma$ deviation from the SM prediction. Our updates also include; model-independent NP formulae for the related observables; and the global fittings of parameters for leptoquark scenarios as well as single NP operator scenarios. Furthermore, we show future potential to indirectly distinguish different NP scenarios with the use of the precise measurements of the polarization observables in $B\to D^{(\ast )}\tau \overline{\nu }$ at the Belle II and the high-$p_{\mathrm{T}}$ flavored-tail searches at the LHC. We also discuss an impact on the LFU violation in ${\rm Y}\to l^{+}{l}^{-}$.

    hep-phhep-exPRD(2024)·55 citations
37. 37*

    QCD Predictions for Meson Electromagnetic Form Factors at High Momenta: Testing Factorization in Exclusive Processes

    Heng-Tong Ding🇨🇳 · Xiang Gao🇺🇸 · Andrew D. Hanlon🇺🇸 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸 · Qi Shi🇨🇳 · Sergey Syritsyn🇺🇸 · Rui Zhang🇺🇸 · Yong Zhao🇺🇸

    We report the first lattice QCD computation of pion and kaon electromagnetic form factors, $F_M(Q^2)$, at large momentum transfer up to 10 and 28 ${\mathrm{GeV}}^2$, respectively. Utilizing physical masses and two fine lattices, we achieve good agreement with JLab experimental results at $Q^2\lesssim 4{\mathrm{GeV}}^2$. For $Q^2\gtrsim 4{\mathrm{GeV}}^2$, our results provide $\text{ab-initio}$ QCD benchmarks for the forthcoming experiments at JLab 12 GeV and future electron-ion colliders. We also test the QCD collinear factorization framework utilizing our high-$Q^2$ form factors at next-to-next-to-leading order in perturbation theory, which relates the form factors to the leading Fock-state meson distribution amplitudes. Comparisons with independent lattice QCD calculations using the same framework demonstrate, within estimated uncertainties, the universality of these nonperturbative quantities.

    ↳ hep-lathep-phnucl-exnucl-thPRL(2024)·34 citations
38. 38*

    Matter in Discrete Space-Times

    P. P. Divakaran

    The unitary representations of the Poincare group of a discrete space-time are constructed, following the Wigner method in continuum relativity. They can be interpreted as elementary particles with one significant new feature: the momentum space being the 4-torus is identified as the Brillouin zone of space-time where all physical phenomena occur. Consequently 4-momentum is defined and conserved only modulo a reciprocal lattice vector of the order of the Planck mass, implying that there is no notion of an invariant mass except when it vanishes. In particular the propagation of massive particles have superluminal phases under very large (trans-Planckian) boosts. This behaviour leads to new features in early cosmology which are not in conflict with current knowledge.

    ↳ gr-qchep-phhep-thmath-ph+21 citation
39. 39*

    Constraining Axion-Like Particles Dark Matter in Coma Berenices with FAST

    Wen-Qing Guo🇨🇳 · Zi-Qing Xia🇨🇳 · Xiaoyuan Huang🇨🇳

    Axions and axion-like particles (ALPs) appear in many extensions of the Standard Model and are being investigated as promising dark matter (DM) candidates. One viable methodology for their detection involves the investigation of the line-like radio emissions from the dwarf spheroidal galaxy, potentially originating from the radiative decay of ALPs or the conversion of ALPs in the magnetic field. In this work, we constrain the properties of ALPs using the 2-hour radio observation of Coma Berenices through the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The $95\%$ upper limits of the ALP-photon coupling are calculated for the ALP decay and conversion scenarios, respectively. Note that the sensitive ALP masses for FAST range from $\sim \mu \mathrm{eV}$ to tens of $\mu \mathrm{eV}$, where ALP can explain the DM abundance naturally. However, our limits are weaker than those of the CAST helioscope, which can provide an independent and complementary check on the ALP non-detection for ground experiments. Furthermore, we evaluate the expected sensitivity on the ALP of FAST with its full designed bandwidth (70 $\mathrm{MHz}$ - 3 $\mathrm{GHz}$) for 100 hours of observation time. Our results indicate that, even with the exceptional sensitivity of the FAST, it is challenging to surpass the existing experimental constraints on ALP DM using radio observation of dSphs, unless the possible enhancements of ALP signals by compact stars in dSphs are considered.

    ↳ astro-ph.HEhep-phPLB(2024)·12 citations
40. 40*

    Note on Warped Compactification -- Finite Brane Potentials and Non-Hermiticity --

    Sudhakantha Girmohanta🇨🇳 · Yuichiro Nakai🇨🇳 · Motoo Suzuki🇺🇸 · Yaoduo Wang🇨🇳 · Junxuan Xu🇨🇳

    We study radius stabilization in the Randall-Sundrum model without assuming any unnaturally large stabilizing scalar potential parameter at the boundary branes ($\gamma$) by the frequently used superpotential method. Employing a perturbative expansion in $1/{\gamma }^2$ and the backreaction parameter, we obtain approximate analytical expressions for the radion mass and wavefunction. We validate them through a dedicated numerical analysis, which solves the linearized coupled scalar and metric field equations exactly. It is observed that the radion mass decreases with decreasing $\gamma$. Below a critical value of $\gamma$, the radion becomes tachyonic, suggesting destabilization of the extra dimension. We also address the issue of non-Hermiticity of the differential operator that determines the radion and Kaluza-Klein (KK) mode wavefunctions in the finite $\gamma$ limit. It is accomplished by finding an explicit form of the general scalar product that re-establishes the orthogonality in the KK decomposition.

    ↳ hep-thgr-qchep-phJHEP(2024)·3 citations
41. 41*

    Hybrid inflation from supersymmetry breaking

    Yermek Aldabergenov🇨🇳 · Ignatios Antoniadis🇹🇭 · Auttakit Chatrabhuti🇹🇭 · Hiroshi Isono🇹🇭

    We extend a recently proposed framework, dubbed inflation by supersymmetry breaking, to hybrid inflation by introducing a waterfall field that allows to decouple the supersymmetry breaking scale in the observable sector from the inflation scale, while keeping intact the inflation sector and its successful predictions: naturally small slow-roll parameters, small field initial conditions and absence of the pseudo-scalar companion of the inflaton, in terms of one free parameter which is the first order correction to the inflaton Kähler potential. During inflation, supersymmetry is spontaneously broken with the inflaton being the superpartner of the goldstino, together with a massive vector that gauges the R-symmetry. Inflation arises around the maximum of the scalar potential at the origin where R-symmetry is unbroken. Moreover, a nearby minimum with tuneable vacuum energy can be accommodated by introducing a second order correction to the Kähler potential. The inflaton sector can also play the role of the supersymmetry breaking 'hidden' sector when coupled to the (supersymmetric) Standard Model, predicting a superheavy superparticle spectrum near the inflation scale. Here we show that the introduction of a waterfall field provides a natural way to end inflation and allows for a scale separation between supersymmetry breaking and inflation. Moreover, the study of the global vacuum describing low energy Standard Model physics can be done in a perturbative way within a region of the parameter space of the model.

    ↳ hep-thhep-phEPJC(2024)·0 citations
42. 42*

    Constraints on the dense matter equation of state from young and cold isolated neutron stars

    Alessio Marino (1,2) · Clara Dehman (1,2)🇪🇸 · Konstantinos Kovlakas (1,2) · Nanda Rea (1,2)🇪🇸 · Jose A. Pons (3)🇪🇸 · D. Viganò (1,2) ((1) Institute of Space Sciences ICE, CSIC, (2) Institut d'Estudis Espacials de Catalunya IEEC, (3) Universitat d'Alacant)

    Neutron stars are the dense and highly magnetic relics of supernova explosions of massive stars. The quest to constrain the Equation of State (EoS) of ultra-dense matter and thereby probe the behavior of matter inside neutron stars, is one of the core goals of modern physics and astrophysics. A promising method involves investigating the long-term cooling of neutron stars, and comparing theoretical predictions with various sources at different ages. However, limited observational data, and uncertainties in source ages and distances, have hindered this approach. In this work, re-analyzing XMM-Newton and Chandra data from dozens of thermally emitting isolated neutron stars, we have identified three sources with unexpectedly cold surface temperatures for their young ages. To investigate these anomalies, we conducted magneto-thermal simulations across diverse mass and magnetic fields, considering three different EoS. We found that the "minimal" cooling model, failed to explain the observations, regardless the mass and the magnetic field, as validated by a machine learning classification method. The existence of these young cold neutron stars suggests that any dense matter EoS must be compatible with a fast cooling process at least in certain mass ranges, eliminating a significant portion of current EoS options according to recent meta-modelling analysis.

    ↳ astro-ph.HEhep-exhep-phnucl-thNature Astron.(2024)·35 citations
43. 43*

    A theoretical perspective on the almost dark galaxy Nube: exploring the fuzzy dark matter model

    Yu-Ming Yang🇨🇳 · Xiao-Jun Bi🇨🇳 · Peng-Fei Yin🇨🇳

    In recent astronomical observations, an almost dark galaxy, designated as Nube, has unveiled an intriguing anomaly in its stellar distribution. Specifically, Nube exhibits an exceptionally low central brightness, with the 2D half-light radius of its stars far exceeding the typical values found in dwarf galaxies, and even surpassing those observed in ultra-diffuse galaxies (UDGs). This phenomenon is difficult to explain within the framework of cold dark matter (CDM). Meanwhile, due to its ultralight particle mass, fuzzy dark matter (FDM) exhibits a de Broglie wavelength on the order of kiloparsecs under the typical velocities of galaxies. The interference between different modes of the FDM wave gives rise to fluctuations in the gravitational field, which can lead to the dynamical heating of stars within galaxies, resulting in an expansion of their spatial distribution. In this paper, we aim to interpret the anomalous stellar distribution observed in Nube as a consequence of the dynamical heating effect induced by FDM. Our findings suggest that a FDM particle mass around $1-2\times 10^{-23}$ eV can effectively account for this anomaly. And we propose that the FDM dynamical heating effect provides a new insight into understanding the formation of field UDGs.

    ↳ astro-ph.COhep-phJCAP(2024)·7 citations
44. 44*

    New ideas on the formation and astrophysical detection of primordial black holes

    Marcos M. Flores🇫🇷 · Alexander Kusenko🇺🇸

    Recently, a number of novel scenarios for primordial black hole (PBH) formation have been discovered. Some of them require very minimal new physics, some others require no new ingredients besides those already present in commonly considered models, such as supersymmetry. At the same time, new strategies have emerged for detection of PBHs. For example, an observation of an orphan kilonova unaccompanied by the gravitational waves signal of merging neutron stars, but associated with a fast radio burst, could be a smoking gun of PBH dark matter. We review some new ideas for PBH formation and detection.

    ↳ astro-ph.COhep-ph11 citations
45. 45*

    Low energy limit from high energy expansion in mass gapped theory

    Hiromasa Takaura🇯🇵

    We present a method to extract the low energy behavior of physical observables from their high energy expansions, systematically calculable via the operator product expansion (OPE), in asymptotically free and mass-gapped theories. By applying the inverse Laplace transform to correlation functions, their analytic structure is modified such that low-energy information connects with high energy expansions. Furthermore, this transformation alleviates the renormalon problem, enabling a more straightforward application of the OPE compared to the OPE before the transformation. We demonstrate that the low energy limit of correlation functions can be accurately extracted using the OPE in the two dimensional $O(N)$ nonlinear $\sigma$ model, serving as a first testing ground.

    ↳ hep-thhep-lathep-phJHEP(2024)·1 citation
46. 46*

    First-order phase transitions in the cores of neutron stars

    Oleg Komoltsev🇳🇴

    I explore various scenarios for the phase transition within neutron-star matter. I do so by generating large model-agnostic ensemble using Gaussian processes, both with and without explicit inclusion of first-order phase transitions (FOPTs). The ensemble is conditioned with state-of-the-art astrophysical and theoretical inputs in a fully Bayesian approach. I study how the current data affect the posterior probability of the location and the strength of FOPT. I find that the previously observed peak structure of the sound speed remains stable against inclusion of FOPTs. While the current data cannot differentiate between a smooth crossover and a first-order phase transition, 91% of the total evidence consists of equations of state with some form of phase changes, such as FOPT occurring within or terminating the stable branch of neutron stars, or an indication of a crossover to quark matter.

    ↳ nucl-thastro-ph.HEhep-phPRD(2024)·26 citations
47. 47*

    The neutrino background from non-jetted active galactic nuclei

    P. Padovani🇩🇪 · R. Gilli🇮🇹 · E. Resconi🇩🇪 · C. Bellenghi🇩🇪 · F. Henningsen🇨🇦

    Aims. We calculate the contribution to the neutrino background from the non-jetted active galactic nuclei (AGN) population following the recent IceCube association of TeV neutrinos with NGC 1068. Methods. We exploit our robust knowledge of the AGN X-ray luminosity function and evolution and convert it to the neutrino band by using NGC 1068 as a benchmark and a theoretically motivated neutrino spectrum. Results. The resulting neutrino background up to redshift 5 does not violate either the IceCube diffuse flux or the upper bounds for non-jetted AGN, although barely so. This is consistent with a scenario where the latter class makes a substantial contribution mostly below 1 PeV, while jetted AGN, i.e. blazars, dominate above this energy, in intriguing agreement with the dip in the neutrino data at ~ 300 TeV. More and better IceCube data on Seyfert galaxies will allow us to constrain the fraction of neutrino emitters among non-jetted AGN.

    ↳ astro-ph.HEastro-ph.GAhep-exhep-phAstron.Astrophys.(2024)·28 citations
48. 48*

    Quintessential interpretation of the evolving dark energy in light of DESI

    Yuichiro Tada🇯🇵 · Takahiro Terada🇯🇵

    The recent result of Dark Energy Spectroscopic Instrument (DESI) in combination with other cosmological data shows evidence of the evolving dark energy parameterized by $w_0{w}_a$CDM model. We interpret this result in terms of a quintessential scalar field and demonstrate that it can explain the DESI result even though it becomes eventually phantom in the past. Relaxing the assumption on the functional form of the equation-of-state parameter $w=w(a)$, we also discuss a more realistic quintessential model. The implications of the DESI result for Swampland conjectures, cosmic birefringence, and the fate of the Universe are discussed as well.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2024)·162 citations
49. 49*

    A Calabi-Yau-to-Curve Correspondence for Feynman Integrals

    Hans Jockers🇩🇪 · Sören Kotlewski🇩🇪 · Pyry Kuusela🇩🇪 · Andrew J. McLeod🇬🇧 · Sebastian Pögel🇩🇪 · Maik Sarve🇩🇪 · Xing Wang🇩🇪 · Stefan Weinzierl🇩🇪

    It has long been known that the maximal cut of the equal-mass four-loop banana integral is a period of a family of Calabi-Yau threefolds that depends on the kinematic variable $z=m^2/p^2$. We show that it can also be interpreted as a period of a family of genus-two curves. We do this by introducing a general Calabi-Yau-to-curve correspondence, which in this case locally relates the original period of the family of Calabi-Yau threefolds to a period of a family of genus-two curves that varies holomorphically with the kinematic variable $z$. In addition to working out the concrete details of this correspondence for the equal-mass four-loop banana integral, we outline when we expect a correspondence of this type to hold.

    ↳ hep-thhep-phmath.AGJHEP(2025)·22 citations
50. 50*

    Black holes, multiple propagation speeds, and energy extraction

    Vitor Cardoso🇩🇰 · Shinji Mukohyama🇯🇵 · Naritaka Oshita🇯🇵 · Kazufumi Takahashi🇯🇵

    The Standard Model of particle physics predicts the speed of light to be a universal speed of propagation of massless carriers. However, other possibilities exist -- including Lorentz-violating theories -- where different fundamental fields travel at different speeds. Black holes are interesting probes of such physics, as distinct fields would probe different horizons. Here, we build an exact spacetime for two interacting scalar fields which have different propagation speeds. One of these fields is able to probe the black hole interior of the other, giving rise to energy extraction from the black hole and a characteristic late-time relaxation. Our results provide further stimulus to the search for extra degrees of freedom, black hole instability, and extra ringdown modes in gravitational-wave events.

    ↳ gr-qcastro-ph.HEhep-phhep-thPRD(2024)·10 citations

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