Tue·Apr 23, 2024Tuesday·April 23, 2024

1. 01*

   Prospects for detecting the couplings of axion-like particle with neutrinos at the CEPC

   Chong-Xing Yue🇨🇳 · Xin-Yang Li🇨🇳 · Xiao-Chen Sun🇨🇳

   We explore the possibility of detecting the couplings of axion-like particle (ALP) with leptons from their loop-level impact on the ALP couplings to electroweak (EW) gauge bosons via the signal process $e^{+}{e}^{-}\to \gamma \gamma E/$ at the Circular Electron Positron Collider (CEPC) and obtain prospective sensitivities to the ALP-lepton couplings. Our numerical results show that the CEPC with the center of mass energy $\sqrt{s}=240(91)$ GeV and the integrated luminosity $\mathcal{L}=5.6(16)$ ab${}^{-1}$ might be sensitive for probing the ALP-lepton couplings in the ALP mass range from $10$ GeV to $130(50)$ GeV, where the prospective sensitivities to the ALP-neutrino coupling $Tr(g_{a\nu \nu })/f_a$ can be as low as $0.016(0.012)$ GeV${}^{-1}$ and $0.0031(2.8\times 10^{-4})$ GeV${}^{-1}$ for $c_R=0$ and $c_R=c_L$, and to the ALP-charged lepton coupling $Tr(g_{a\ell \ell })/f_a$ can be as low as $0.035(0.07)$ GeV${}^{-1}$ for $c_L=0$. We find that the prospective sensitivities given by the CEPC are not covered by the current and expected exclusion regions in some ALP mass intervals. The CEPC has the potential for exploring the ALP-neutrino couplings via some promising processes induced by the ALP-EW gauge boson couplings in the future.

   hep-phEPJC(2024)·6 citations
2. 02*

   String-based parametrization of nucleon GPDs at any skewness: a comparison to lattice QCD

   Kiminad A. Mamo🇺🇸 · Ismail Zahed🇺🇸

   We introduce a string-based parametrization for nucleon quark and gluon generalized parton distributions (GPDs) valid at all skewness values. The conformal moments of the GPDs are expressed as sums of the spin-j nucleon A-form factor, and the skewness-dependent spin-j nucleon D-form factor. This representation, which fulfills the polynomiality condition (due to Lorentz invariance) and does not rely on model-specific assumptions, is derived from t-channel string exchanges in AdS spaces. The spin-j nucleon D-form factor is closely related to the the spin-j nucleon A-form factor. We use the Mellin moments from empirical parton distributions to model the spin-j nucleon A-form factors. Using only five Regge slope parameters, fixed from the electromagnetic and gravitational form factors, our string-based parametrization generates accurate singlet, non-singlet, isovector, and flavor-separated nucleon quark GPDs, along with symmetric nucleon gluon GPDs from their Mellin-Barnes integral representations. Our isovector nucleon quark GPD is in agreement with existing lattice data. Our string-based parametrization should facilitate the empirical extraction and global analysis of nucleon GPDs in exclusive processes, bypassing the deconvolution challenge.

   hep-phhep-thPRD(2024)·21 citations
3. 03*

   Phenomenology of 3-3-1 models with radiative inverse seesaw mechanism

   V. H. Binh🇻🇳 · Cesar Bonilla🇨🇱 · A. E. Cárcamo Hernández🇨🇱 · D. T. Huong🇻🇳 · Vishnudath K. N.🇨🇱 · H. N. Long🇻🇳 · P. N. Thu🇻🇳 · Iván Schmidt🇨🇱

   We propose two models based on the $SU(3{)}_C\times SU(3{)}_L\times U(1{)}_X$ gauge symmetry, each incorporating distinct inverse seesaw mechanisms for generating neutrino masses at the radiative level. Therefore, neutrino masses are suppressed by the radiative nature of the mass generation mechanism, which occurs after the spontaneous breaking of the global lepton number symmetry. Both scenarios discussed here are characterized by the presence of vector-like charged leptons, which are involved in generating the masses of the Standard Model charged leptons. These additional vector-like fermions contribute to the anomalous magnetic moments of the electron and the muon. We perform a detailed analysis of the scalar sectors, show that these models can successfully accommodate the observed baryon asymmetry through resonant leptogenesis, and compute charged lepton flavor-violating decays, such as $\mu \to e\gamma$. We discuss the constraints of the model arising from these processes and those associated the non-unitarity of the lepton mixing matrix.

   hep-phPRD(2024)·9 citations
4. 04*

   Muon Anomalous Magnetic Moment in Noncommutative Space-Time

   Zahra Rezaei🇮🇷 · Aboozar Ghaffary🇮🇷

   The explanation of the muon anomalous magnetic moment ($\mu$-AMM) requires new physics beyond the Standard Model. In this work, we investigate the effects of noncommutative space-time on the $\mu$-AMM within the Seiberg-Witten map framework, analyzing both tree-level and loop-level diagrams. Additionally, we examine the $\mu$-AMM by studying the scattering cross-section of electron-positron annihilation into muon-antimuon pairs $(e^{-}{e}^{+}\to {\mu }^{-}{\mu }^{+})$. Previous studies have explored the implications of noncommutative space-time through various processes, leading to different bounds on the noncommutative parameter ${\theta }^{\mu \nu }$. Our analysis estimates ${\theta }^{\mu \nu }\sim (43\mathrm{T}eV{)}^{-2}$ for both tree-level and loop-level contributions when noncommutative space-time accounts for the entire observed $\mu$-AMM. If noncommutative effects are responsible for only 10$\%$ of the $\mu$-AMM, the constraint relaxes to approximately $(136\mathrm{T}eV{)}^{-2}$. Furthermore, by comparing the noncommutative cross-section of $e^{-}{e}^{+}\to {\mu }^{-}{\mu }^{+}$ with experimental data, we derive an approximate bound of $(90\mathrm{T}eV{)}^{-2}$ which corresponds to a 23$\%$ contribution to the $\mu$-AMM.

   hep-phJ.Phys.G(2026)·0 citations
5. 05*

   The Cosmological Constant Problem and the Extra Dimensions of $\mathcal{N}=2$ $\mathcal{D}=5$ Supergravity

   Safinaz Salem🇪🇬

   We propose an interpretation for the cosmological constant problem based on modeling the universe as a 3-brane embedded in the bulk of 5-dimensional supergravity with hypermultiplets. When solving the modified Friedmann equations the complex structure moduli of the Calabi-Yau manifold cancel the large value of the vacuum energy density on the brane, wherein this value transfers to an Anti-de Sitter fifth dimensional bulk compactified on a scale $(\sim 10^{-26}\text{m})$. An effective dark energy density is produced on the brane which equals the observed value responsible for the late-time acceleration of the universe. The bulk undergoes a decelerated contraction while we show that cosmic expansion of the brane-universe consists with the recent observed data of the $\Lambda$CDM model. On the other hand, through this model, the hierarchy between the electroweak scale $(M_{EW}=100\text{GeV})$ and the Planck scale $(M_{pl}\sim 10^{18}\text{GeV})$ is interpreted by compactifying the 6-extra dimensions of $\mathcal{D}=5$ supergravity on a sub-millimeters scale, where the fundamental scale of gravity within these extra dimensions is ${\mathcal{M}}_{EW}$.

   hep-phPhys.Dark Univ.(2024)·1 citation
6. 06*

   Chern-Simmons electrodynamics and torsion dark matter axions

   Zhifu Gao (1)🇨🇳 · Luiz C. Garcia de Andrade (2) ((1) Xinjiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi, Xinjiang, China, (2) Cosmology and Gravitation group. Departamento deFísica Teórica - IF - UERJ, Rio de Janeiro, RJ, Brazil and Institute for Cosmology and Philosophy of Nature, Trg, Florjana, Croatia)🇧🇷

   In this paper, we delve into the influence of torsion axial pseudo vector on dark photons in an axion torsionic background, as investigated previously by Duncan et al[ Nucl Phys B 387:215 (1992)]. Notably, axial torsion, owing to its significantly greater mass compared to axions, gives rise to magnetic helicity in torsionful Chern-Simons (CS) electrodynamics, leading to the damping of magnetic fields. In QCD scale the damping from dark massive photons leads us to obtain a magnetic field of $10^{-8}$ Gauss, which is approximated the order of magnitude of magnetic fields at present universe. This result is obtained by considering that torsion has the value of the 1 MeV at the early universe, and can be improved to the higher value of $10^{-3}$ Gauss when the axial torsion 0-component is given by $10^8$ MeV and the mass of dark photon is approximated equal to the axion. The axion plays a crucial role in achieving CS dynamo action arising from axions. This study is useful in deepening our understanding of fundamental physics, from nuclear interactions to the nature of dark matter.

   hep-phastro-ph.HEhep-th4 citations
7. 07*

   Electron and Muon $(g-2{)}_{e,\mu }$ Anomalous Magnetic Moment in $U(1{)}_{L_e-L_{\mu }}$ Symmetry Model

   Rishu Verma🇮🇳 · Ankush🇮🇳 · B. C. Chauhan🇮🇳

   The nature of neutrino (whether Majorana or Dirac) and the origin of neutrino masses are still some of the mysteries to be resolved. Also, the recent results on (g-2)${}_{e,\mu }$ measurements deviate from the Standard Model (SM) predictions and motivate us towards new physics beyond the SM. In this work, we propose a model with the minimal field content in the framework of anomaly free extension of Standard Model; i.e. U(1)${}_{L_e-L_{\mu }}$ symmetry model. We find this model capable of explaining the low energy neutrino phenomenology and anomalous magnetic moment(g-2)${}_{e,\mu }$ of electron and muon, simultaneously. The field content is extended by a SU(2)${}_L$ singlet scalar field $\varphi$ and three right handed neutrinos N${}_R$(R = 1,2,3). Thus, the neutrino masses are generated using the Type-I seesaw mechanism. The extended model leads to the results, which are in consistency with the experimental values of (g-2)${}_{e,\mu }$ and also satisfy all the relevant experimental data.

   hep-ph1 citation
8. 08*

   Ratios of the light quark masses: Cubic curve vs ellipse

   A.A. Osipov🇷🇺

   The bounds on the light quark masses are obtained by fitting the squares of pseudoscalar meson masses $m_{\pi }^2$ and $m_K^2$ to second order in $1/N_c$ expansion. The result is an algebraic cubic curve whose coefficients are the known Weinberg values for the quark mass ratios $m_u/m_d$ and $m_s/m_d$. Additional restrictions arise when using the ratio $m_s/m_{ud}=27.23(10)$ quoted by FLAG for lattice simulations with four quark flavors. This provides a tight constraint on the ratio $m_u/m_d=0.455(8)$.

   hep-phPRD(2024)·4 citations
9. 09*

   Transverse structure of the proton beyond leading twist: A light-front Hamiltonian approach

   Zhimin Zhu · Siqi Xu · Jiatong Wu · Hongyao Yu · Zhi Hu · Jiangshan Lan · Chandan Mondal · Xingbo Zhao · James P. Vary · BLFQ Collaboration

   Within the Basis Light-Front Quantization framework, we systematically investigate the subleading twist (twist-3) transverse-momentum-dependent parton distribution functions (TMDs) of the proton beyond the Wandzura-Wilczek (WW) approximation. The subleading twist TMDs are not independent and can be decomposed into twist-2 and genuine twist-3 terms from the equations of motion. The latter involves quark-quark-gluon correlations and contains interferences between two light-front Fock sectors, $|qqq⟩$ and $|qqqg⟩$, which are usually neglected in the WW approximation.

   hep-phhep-thPLB(2024)·17 citations
10. 10*

    Entanglement in flavored scalar scattering

    Kamila Kowalska🇵🇱 · Enrico Maria Sessolo🇵🇱

    We investigate quantum entanglement in high-energy $2\to 2$ scalar scattering, where the scalars are characterized by an internal flavor quantum number acting like a qubit. Working at the 1-loop order in perturbation theory, we build the final-state density matrix as a function of the scattering amplitudes connecting the initial to the outgoing state. In this construction, the unitarity of the $S$-matrix is guaranteed at the required order by the optical theorem. We consider the post-scattering entanglement between the momentum and flavor degrees of freedom of the final-state particles, as well as the entanglement of the two-qubit flavor subsystem. In each case we identify the couplings of the scalar potential that can generate, destroy, or transfer entanglement between different bipartite subspaces of the Hilbert space.

    hep-phhep-thquant-phJHEP(2024)·61 citations
11. 11*

    Discovering Quirks through Timing at FASER and Future Forward Experiments at the LHC

    Jonathan L. Feng🇺🇸 · Jinmian Li🇨🇳 · Xufei Liao🇨🇳 · Jian Ni🇨🇳 · Junle Pei🇨🇳

    Quirks are generic predictions of strongly-coupled dark sectors. For weak-scale masses and a broad range of confining scales in the dark sector, quirks can be discovered only at the energy frontier, but quirk--anti-quirk pairs are produced with unusual signatures at low $p_T$, making them difficult to detect at the large LHC detectors. We determine the prospects for discovering quirks using timing information at FASER, FASER2, and an "ultimate detector" in the far-forward region at the LHC. NLO QCD corrections are incorporated in the simulation of quirk production, which can significantly increase the production rate. To accurately propagate quirk pairs from the ATLAS interaction point to the forward detectors, the ionization energy loss of charged quirks traveling through matter, the radiation of infracolor glueballs and QCD hadrons during quirk pair oscillations, and the annihilation of quirkonium are properly considered. The quirk signal is separated from the large muon background using timing information from scintillator detectors by requiring either two coincident delayed tracks, based on arrival times at the detector, or two coincident slow tracks, based on time differences between hits in the front and back scintillators. We find that simple cuts preserve much of the signal, but reduce the muon background to negligible levels. With the data already collected, FASER can discover quirks in currently unconstrained parameter space. FASER2, running at the Forward Physics Facility during the HL-LHC era, will greatly extend this reach, probing the TeV-scale quirk masses motivated by the gauge hierarchy problem for the broad range of dark-sector confining scales between 100 eV and 100 keV.

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

    Producing Fully-Charmed Tetraquarks via Charm Quark Fragmentation in Colliders

    Xiao-Wei Bai🇨🇳 · Feng Feng🇨🇳 · Chang-Man Gan🇨🇳 · Yingsheng Huang🇺🇸 · Wen-Long Sang🇨🇳 · Hong-Fei Zhang🇨🇳

    Within the framework of nonrelativistic QCD (NRQCD), we calculate the fragmentation function for a charm quark into an $S$-wave fully-charmed tetraquark, denoted as $T_{4c}$. The charm-to-$T_{4c}$ fragmentation function is expressed as a sum of products of the perturbatively calculable short-distance coefficients and the nonperturbative long-distance matrix elements (LDMEs). The short-distance coefficients are ascertained through the perturbative matching procedure at lowest order in ${\alpha }_s$ expansion. The LDMEs are approximated using the $T_{4c}$ four-body wave functions at the origin, which have been evaluated by various phenomenological potential models in literature. Incorporating the celebrated QCD factorization and the charm-to-$T_{4c}$ fragmentation function, we predict the $T_{4c}$ production rate at high transverse momentum $p_T$ regime in colliders. %After implementing appropriate kinematic constraints, Both the differential distribution over $p_T$ and the integrated cross sections are predicted at the \texttt{LHC}. The cross sections for $T_{4c}$ states production can reach several femtobarns to several hundreds femtobarns, suggesting a substantial potential for $T_{4c}$ event production at the \texttt{LHC}. Additionally, we estimate for the photoproduction of $T_{4c}$ in electron-proton ($ep$) collisions. It is observed that the cross sections for these processes are moderate at the \texttt{HERA} and \texttt{EIC}, and relatively small at the \texttt{EicC}. Given the luminosities of these colliders, the prospect of detecting these fully-charmed tetraquarks at $ep$ colliders is somewhat challenging.

    hep-phJHEP(2024)·28 citations
13. 13*

    Chiral-odd generalized parton distributions of sea quarks at $\xi =0$ in the light-cone quark model

    Xiaoyan Luan🇨🇳 · Zhun Lu🇨🇳

    We study the chiral-odd generalized parton distributions (GPDs) of the $\bar{u}$ and $\bar{d}$ quarks inside the proton at zero skewness using the overlap representation within the light cone formalism. Using the light cone wave functions (LCWFs) of the proton obtained from the baryon-meson fluctuation model in terms of the $|q\bar{q}B⟩$ Fock states, we provide the expressions of the GPDs ${\tilde{H}}_T^{\bar{q}/P}(x,0,t)$, $H_T^{\bar{q}/P}(x,0,t)$ and $E_T^{\bar{q}/P}(x,0,t)$ for $\bar{q}=\bar{u}$ and $\bar{d}$. Numerical results for these GPDs in momentum space as well as in impact parameter space are presented. We further investigate certain combinations of the chiral-odd GPDs in impact parameter space to the spin-orbit correlation effect of the sea quarks.

    hep-phPRD(2024)·4 citations
14. 14*

    DALI sensitivity to streaming axion dark matter

    Javier De Miguel🇯🇵 · Abaz Kryemadhi🇺🇸 · Konstantin Zioutas🇬🇷

    Dark matter substructures emerge naturally in a scenario in which the axion angular field acquires propagating degrees of freedom in a post-inflationary Universe. The DALI experiment is a new generation wavy dark matters interferometer currently in prototyping. Although DALI's main objective is to explore the virialized DM in our Galaxy, to a large degree in this article we explore the prospect for detection of fine grained streams made of axions that would enter the Solar System, as suggested by previous work. We find that DALI will have a sensitivity to encounters with these coherent objects that fully spans the window defined by the coupling strength to photons of representative axion models over a stacked bandwidth of two decades in mass.

    hep-phastro-ph.COastro-ph.IMhep-exPRD(2025)·10 citations
15. 15*

    Two-Loop Contributions to the Anomalous Chromomagnetic Dipole Moment of the Top Quark in Two-Higgs-Doublet Models

    Subhadip Bisal🇮🇳

    We present the analytical results for the anomalous chromomagnetic moment of a quark at the one-loop and two-loop levels through model-independent parameterizations, considering the external gluon to be off-shell. Then, we consider different types of two-Higgs doublet models with the momentum transfer of the external gluon, $q^2=\pm M_Z^2$, and $0$, for the numerical evaluations thereof for the top quark. We find that the contributions in the two-Higgs-doublet models are on the order of $\mathcal{O}(10^{-3})$ at the one-loop level and $\mathcal{O}(10^{-4})$ at the two-loop level, where the one-loop and two-loop contributions interfere destructively, resulting in the overall contributions being on the order of $\mathcal{O}(10^{-3})$ with a positive sign.

    hep-phPLB(2024)·3 citations
16. 16*

    Likelihood analysis of the newly observed $f_0(2020)$, $f_0(2330)$, and $f_0(2470)$ in $J/\psi \to \gamma {\eta }^{\prime }{\eta }^{\prime }$ as high-lying unflavored scalar mesons

    Cheng-Xi Liu🇨🇳 · Li-Ming Wang🇨🇳 · Ting-Yan Li🇨🇳 · Xiang Liu🇨🇳

    Light mesons have always been an important part of the whole hadron family, once inspiring the SU(3) classification of hadrons as a typical example~\cite{Gell-Mann:1964ewy}. Until now, the search for light mesons has been an ongoing task in hadron physics. In particular, with the accumulation of experimental data, more and more light flavor mesons with the masses around 2.2 GeV were found, including the $Y(2175)$ observed in $J/\psi \to \eta \varphi f_0(980)$~\cite{BES:2007sqy} and the $X(2370)$ reported in the decay of $J/\psi \to \gamma {\eta }^{\prime }{\pi }^{+}{\pi }^{-}$~\cite{BESIII:2010gmv,BESIII:2019wkp}. These progresses show that there is a chance to construct the light meson family, which is also an effective approach to deepen our understanding of non-perturbative behavior of the strong interaction.

    hep-phhep-exPRD(2024)·2 citations
17. 17*

    Local univalence versus stability and causality in hydrodynamic models

    Roya Heydari🇮🇷 · Farid Taghinavaz🇮🇷

    Our main objective is to compare the analytic properties of hydrodynamic series with the stability and causality conditions applied to hydrodynamic modes. Analyticity, in this context, implies that the hydrodynamic series behaves as a univalent or single-valued function. Stability and causality adhere to physical constraints where hydrodynamic modes neither exhibit exponential growth nor travel faster than the speed of light. Through an examination of various hydrodynamic models, such as the Muller-Israel-Stewart (MIS) and the first-order hydro models like the BDNK (Bemfica-Disconzi-Noronha-Kovtun) model, we observe no new restrictions stemming from the analyticity limits in the shear channel of these models. However, local univalence is maintained in the sound channel of these models despite the global divergence of the hydrodynamic series. Notably, differences in the sound equations between the MIS and BDNK models lead to distinct analyticity limits. The MIS model's sound mode remains univalent at high momenta within a specific transport range. Conversely, in the BDNK model, the univalence of the sound mode extends to intermediate momenta across all stable and causal regions. Generally, the convergence radius is independent of univalence and the given dispersion relation predominantly influences their correlation. For second-order frequency dispersions, the relationship is precise, i.e. within the convergence radius, the hydro series demonstrates univalence. However, with higher-order dispersions, the hydro series is locally univalent within certain transport regions, which may fall within or outside the stable and causal zones.

    hep-phhep-thmath-phmath.MP+11 citation
18. 18*

    Complete $CP$ Eigen-bases of Mesonic Chiral Lagrangian up to $p^8$-order

    Xuan-He Li🇨🇳 · Hao Sun🇨🇳 · Feng-Jie Tang🇨🇳 · Jiang-Hao Yu🇨🇳

    Chiral perturbation theory systematically describes the low energy dynamics of meson and baryons using nonlinear Nambu-Goldstone fields. Using the Young tensor technique, we construct the pure mesonic effective operators up to $p^8$-order, one-to-one corresponding to contact amplitudes with the on-shell Adler zero condition. The off-shell external sources, non-vanishing under equation-of-motion conditions, are also added to the operator bases. We also show the invariant tensor bases using the Young tableau is equivalent to the trace bases with Cayley-Hamilton relations. Separated into different $CP$ eigenstates, at $\mathcal{O}(p^8)$ we obtain the operator lists of the 567 $C$+$P$+ operators, 483 $C$+$P$- operators, 376 $C$-$P$+ operators, and 408 $C$-$P$- operators for $SU(2)$ case, while there are 1959 $C$+$P$+ operators, 1809 $C$+$P$- operators, 1520 $C$-$P$+ operators, and 1594 $C$-$P$- operators for $SU(3)$ case, consistent with results using the Hilbert series.

    hep-phJHEP(2024)·10 citations
19. 19*

    Topological susceptibility and axion potential in two-flavor superconductive quark matter

    Fabrizio Murgana🇮🇹 · David E. Alvarez Castillo🇵🇱 · Ana G. Grunfeld🇦🇷 · Marco Ruggieri🇮🇹

    We study the potential of the axion, $a$, of Quantum Chromodynamics, in the two-flavor color superconducting phase of cold and dense quark matter. We adopt a Nambu-Jona-Lasinio-like model. Our interaction contains two terms, one preserving and one breaking the $U(1{)}_A$ symmetry: the latter is responsible of the coupling of axions to quarks. We introduce two quark condensates, $h_L$ and $h_R$, describing condensation for left-handed and right-handed quarks respectively; we then study the loci of the minima of the thermodynamic potential, $\Omega$, in the $(h_L,h_R)$ plane, noticing how the instanton-induced interaction favors condensation in the scalar channel when the $\theta -$angle, $\theta =a/f_a$, vanishes. Increasing $\theta$ we find a phase transition where the scalar condensate rotates into a pseudo-scalar one. We present an analytical result for the topological susceptibility, $\chi$, in the superconductive phase, which stands both at zero and at finite temperature. Finally, we compute the axion mass and its self-coupling. In particular, the axion mass $m_a$ is related to the full topological susceptibility via $\chi =m_a^2{f}_a^2$, hence our result for $\chi$ gives an analytical result for $m_a$ in the superconductive phase of high-density Quantum Chromodynamics.

    hep-phhep-thnucl-thPRD(2024)·11 citations
20. 20*

    Deviation from $\mu -\tau$ Symmetry with New Approaches

    Pralay Chakraborty🇮🇳 · Tanmay Dev🇮🇳 · Subhankar Roy🇮🇳

    We propose two new predictive neutrino mass matrix textures that deviate from $\mu$-$\tau$ symmetry and explore their phenomenological implications. These textures are significant due to their predictive nature and the unique approach they introduce for breaking the $\mu$-$\tau$ symmetry. Both textures predict six physical parameters and impose sharp constraints on ${\theta }_{23}$ and $\delta$, considering both normal and inverted neutrino mass orderings. In addition, we realize the textures in their exact form within the framework of the seesaw mechanism, based on the $SU(2{)}_L\times A_4\times Z_3$ symmetry group.

    hep-phEPL(2025)·6 citations
21. 21*

    Study of exclusive decays of $B_s\to \psi (1S,2S)K_s$ and $B_s\to {\eta }_c(1S,2S)K_s$

    Lopamudra Nayak🇮🇳 · Sonali Patnaik🇮🇳 · Priyanka Sadangi🇮🇳 · Sanjay Kumar Swain🇮🇳

    We analyze the exclusive two-body nonleptonic decays of $B_s$ meson to ground as well as radially excited $2S$ charmonium state with a light meson $K_s$, induced by the $b\to c\bar{c}d$ transition. Within the framework of relativistic independent quark (RIQ) model based on a flavor-independent interaction potential in scalar-vector harmonic form, we calculate the weak form factors from the overlapping integrals of meson wave function obtained in this model. Using the factorization approximation, we predict the branching fractions for the $B_s\to \psi (1S,2S)K_s$ and $B_s\to {\eta }_c(1S,2S)K_s$, which can be compared with future theoretical predictions. Branching fraction for $B_s\to J/\psi K_s$ decay is found to be in good agreement with the data from LHCb Collaboration, whereas for $B_s\to \psi (2S)K_s$, it is found to be within the detection ability of the CMS Collaboration. We also predict the ratios of branching fractions $(\mathcal{R})$, which are in broad agreement with the data from LHCb Collaboration. These results indicate that the present approach works well in the description of exclusive nonleptonic $B_s$ decays within the framework of the RIQ model.

    hep-phPRD(2024)·5 citations
22. 22*

    The Alaric parton shower for hadron colliders

    Stefan Höche🇺🇸 · Frank Krauss🇬🇧 · Daniel Reichelt🇬🇧

    We introduce the Alaric parton shower for simulating QCD radiation at hadron colliders and present numerical results from an implementation in the event generator Sherpa. Alaric provides a consistent framework to quantify certain systematic uncertainties which cannot be eliminated by comparing the parton shower with analytic resummation. In particular, it allows to study recoil effects away from the soft and collinear limits without the need to change the evolution variable or the splitting functions. We assess the performance of Alaric in Drell-Yan lepton pair and QCD jet production, and present the first multi-jet merging for the new algorithm.

    hep-phPRD(2025)·46 citations
23. 23*

    Leading Axion-Photon Sensitivity with NuSTAR Observations of M82 and M87

    Orion Ning🇺🇸 · Benjamin R. Safdi🇺🇸

    We perform the most sensitive search to-date for the existence of ultralight axions using data from the NuSTAR telescope. We search for stellar axion production in the M82 starburst galaxy and the M87 central galaxy of the Virgo cluster and then the subsequent conversion into hard X-rays in the surrounding magnetic fields. We sum over the full stellar populations in these galaxies when computing the axion luminosity, and we account for the conversion of axions to photons by using magnetic field profiles in simulated IllustrisTNG analogue galaxies. We show that analyzing NuSTAR data towards these targets between roughly 30 to 70 keV shows no evidence for axions and leads to robust constraints on the axion-photon coupling at the level of $|g_{a\gamma \gamma }|\lesssim 6.4\times 10^{-13}$ GeV${}^{-1}$ for $m_a\lesssim 10^{-10}$ eV at 95% confidence.

    hep-phastro-ph.GAastro-ph.HEPRL(2025)·61 citations
24. 24*

    Holography for Sp(2$N_c$) Gauge Dynamics: from Composite Higgs to Technicolour

    Johanna Erdmenger🇩🇪 · Nick Evans🇬🇧 · Yang Liu🇩🇪 · Werner Porod🇩🇪

    We study Sp(2$N_c$) gauge dynamics with two Dirac fermion flavours in the fundamental representation. These strongly coupled systems underlie some composite Higgs models with a global symmetry breaking pattern SU(4)$\to$Sp(4), leading to a light quartet of pseudo-Goldstone bosons that can play the role of the Higgs. Including four-fermion interactions can rotate the vacuum to a technicolour breaking pattern. Using gauge/gravity duality, we study the underlying gauge dynamics. Our model incorporates the $N_c$-specific running of the fermion anomalous dimension and can thus distinguish between specific gauge groups. We determine the bound-state spectrum of the UV SU(4)$\to$Sp(4) symmetry breaking model, also including fermion masses and mass splitting, and display the $N_c$ dependence. The inclusion of a four-fermion interaction shows the emergence of three Goldstone bosons on the path to technicolour dynamics.

    hep-phhep-thJHEP(2024)·20 citations
25. 25*

    Boosting Beyond: A Novel Approach to Probing Top-Philic Resonances at the LHC

    Luc Darmé🇫🇷 · Benjamin Fuks🇫🇷 · Hao-Lin Li🇧🇪 · Matteo Maltoni🇧🇪 · Olivier Mattelaer🇧🇪 · Julien Touchèque🇧🇪

    We introduce a novel search strategy for heavy top-philic resonances that induce new contributions to four-top production at the LHC. We capitalize on recent advances in top-tagging performance to demonstrate that the final state, that is expected to be boosted based on current limits, can be fully reconstructed and exploited. Notably, our approach promises bounds on new physics cross-sections that are a few to 60 times stronger than those obtained with existing searches, showcasing its unprecedented effectiveness in probing top-philic new physics.

    hep-phhep-exPRD(2025)·4 citations
26. 26*

    Enhanced Muonization by Active-Sterile Neutrino Mixing in Protoneutron Stars

    Anupam Ray🇺🇸 · Yong-Zhong Qian🇺🇸

    We study ${\nu }_{\mu }$-${\nu }_s$ and ${\bar{\nu }}_{\mu }$-${\bar{\nu }}_s$ mixing in the protoneutron star (PNS) created in a core-collapse supernova (CCSN). We point out the importance of the feedback on the general composition of the PNS in addition to the obvious feedback on the ${\nu }_{\mu }$ lepton number. We show that for our adopted mixing parameters $\delta m^2\sim 10^2$~keV${}^2$ and ${\sin }^{2}2\theta$ consistent with the current constraints, sterile neutrino production is dominated by the Mikheyev-Smirnov-Wolfenstein conversion of ${\bar{\nu }}_{\mu }$ into ${\bar{\nu }}_s$ and that the subsequent escape of ${\bar{\nu }}_s$ increases the ${\nu }_{\mu }$ lepton number, which in turn enhances muonization of the PNS primarily through ${\nu }_{\mu }+n\to p+{\mu }^{-}$. While these results are qualitatively robust, their quantitative effects on the dynamics and active neutrino emission of CCSNe should be evaluated by including ${\nu }_{\mu }$-${\nu }_s$ and ${\bar{\nu }}_{\mu }$-${\bar{\nu }}_s$ mixing in the simulations.

    hep-phastro-ph.HEPRD(2024)·9 citations
27. 27*

    Growing Evidence for a Higgs Triplet

    Andreas Crivellin🇨🇭 · Saiyad Ashanujjaman🇨🇳 · Sumit Banik🇨🇭 · Guglielmo Coloretti🇨🇭 · Siddharth P. Maharathy🇮🇳 · Bruce Mellado🇿🇦

    Despite intensive searches at the LHC, no new fundamental particle has been discovered since the discovery of the 125 GeV Higgs boson. In general, a new physics discovery is challenging without a UV-complete model because different channels and observables cannot be combined directly and unambiguously. Moreover, without indirect hints for new particles, the parameter space to be searched is huge, resulting in diminished significance due to the look-elsewhere effect. Several LHC searches with multiple leptons in the final state point towards the existence of a new Higgs boson with a mass in the 140-160 GeV range, decaying mostly to a pair of W bosons. This dominant decay mode motivates a Higgs triplet with zero hypercharge, which also predicts a heavier-than-expected $W$-boson as indicated by the CDF-II measurement. Within this simple and predictive model, we simulate and combine channels of associated di-photon production. Considering the run-2 results of ATLAS, including those presented recently at the Moriond conference, a significance of 4.3$\sigma$ is obtained for a mass of 152 GeV. This is the largest statistical evidence for a new narrow resonance observed at the LHC.

    hep-phhep-exCPC(2025)·25 citations
28. 28*

    Cosmic-Ray Propagation Models Elucidate the Prospects for Antinuclei Detection

    Pedro De La Torre Luque🇸🇪 · Martin Wolfgang Winkler🇺🇸 · Tim Linden🇸🇪

    Tentative observations of cosmic-ray antihelium by the AMS-02 collaboration have re-energized the quest to use antinuclei to search for physics beyond the standard model. However, our transition to a data-driven era requires more accurate models of the expected astrophysical antinuclei fluxes. We use a state-of-the-art cosmic-ray propagation model, fit to high-precision antiproton and cosmic-ray nuclei (B, Be, Li) data, to constrain the antinuclei flux from both astrophysical and dark matter annihilation models. We show that astrophysical sources are capable of producing $\mathcal{O}(1)$ antideuteron events and $\mathcal{O}(0.1)$ antihelium-3 events over 15~years of AMS-02 observations. Standard dark matter models could potentially produce higher levels of these antinuclei, but showing a different energy-dependence. Given the uncertainties in these models, dark matter annihilation is still the most promising candidate to explain preliminary AMS-02 results. Meanwhile, any robust detection of antihelium-4 events would require more novel dark matter model building or a new astrophisical production mechanism.

    ↳ astro-ph.HEhep-phJCAP(2024)·18 citations
29. 29*

    Stochastic fluctuations and stability in birth-death population dynamics: two-component Langevin equation in path-integral formalism

    Shigehiro Yasui🇯🇵 · Yutaka Hatakeyama · Yoshiyasu Okuhara

    We discuss the stochastic process of creation and annihilation of particles, i.e., the $A^n\rightleftarrows B$ process in which $n$ particles $A$s and one particle $B$ are transformed to each other. Considering the case that the stochastic fluctuations are dependent on the numbers of $A$ and $B$, we apply the Langevin equation for the stochastic time-evolution of the numbers of $A$ and $B$. We analyze the Langevin equation in the path-integral formalism, and show that the new driving force is generated dynamically by the stochastic fluctuations. We present that the generated driving force leads to the nontrivial stable equilibrium state. This equilibrium state is regarded as the new state of order which is induced effectively by stochastic fluctuations. We also discuss that the formation of such equilibrium state requires at least two stochastic variables in the stochastic processes.

    ↳ cond-mat.stat-mechhep-phq-bio.PE0 citations
30. 30*

    The Self-Consistency of DESI Analysis and Comment on "Does DESI 2024 Confirm $\Lambda$CDM?"

    Deng Wang (IFIC, Spain)🇪🇸

    We demonstrate that the constraints on the evolution of dark energy implemented by the DESI collaboration may be insufficient or incomplete using their own BAO data. Using large enough prior ranges for the present-day equation of state of dark energy ${\omega }_0$ and amplitude of dark energy evolution ${\omega }_a$, we obtain the complete $1\sigma$ and $2\sigma$ constraints ${\omega }_0=1.04_{-1.00-1.90}^{+0.91+2.00}$ and ${\omega }_a=-7.4_{-3.2-7.3}^{+3.8+6.8}$ indicating a beyond $2\sigma$ preference of quintessence-like dark energy today and an evidence of evolving dark energy at beyond $2\sigma$ CL, respectively. Our results are different from ${\omega }_0=-0.55_{-0.21}^{+0.39}$ and the $2\sigma$ upper limit ${\omega }_a<-1.32$ reported by the DESI collaboration \cite{DESI:2024mwx}. Employing a data combination of cosmic microwave background, DESI BAO and type Ia supernova, we obtain the $1\sigma$, $2\sigma$ and $3\sigma$ constraints ${\omega }_0=-0.707_{-0.089-0.17-0.22}^{+0.089+0.18+0.24}$ and ${\omega }_a=-1.09_{-0.31-0.72-1.00}^{+0.38+0.67+0.82}$, which reveals a $\sim 4\sigma$ evidence of dynamical dark energy when the redshift $z\lesssim 0.1$. We verify that the BAO data point from luminous red galaxies at the effective redshift $z_{\mathrm{eff}}=0.51$ hardly affects the joint constraint from the data combination of cosmic microwave background, DESI BAO and type Ia supernova. We also point out the shortcomings and advantages of the binning method widely used in cosmological analyses.

    ↳ astro-ph.COastro-ph.HEgr-qchep-ph+170 citations
31. 31*

    Special Issue on Modified Gravity Approaches to the Tensions of $\Lambda$CDM: Goals and Highlights

    Eleonora Di Valentino🇬🇧 · Leandros Perivolaropoulos🇬🇷 · Jackson Levi Said🇲🇹

    The Special Issue on "Modified Gravity Approaches to the Tensions of $\Lambda$CDM"} in the Universe journal tackles significant challenges faced by the $\Lambda$CDM model, including discrepancies in the Hubble constant, growth rate of structures, and cosmological anisotropies. These issues suggest foundational cracks in the model, raising questions about the validity of General Relativity, dark energy, and cosmological principles at large scales. This collection brings together leading researchers to delve into Modified Gravity theories as potential solutions. Covering approaches from Scalar-Tensor theories to $f(R,T)$ gravity and beyond, each contribution presents innovative research aimed at addressing the limitations of the $\Lambda$CDM model. This Special Issue not only highlights the theoretical and empirical strengths of Modified Gravity models but also opens avenues for future investigations, emphasizing the synergy between theoretical advancements and observational evidence to deepen our cosmological understanding.

    ↳ gr-qchep-phhep-th5 citations
32. 32*

    Superoscillations in High Energy Physics and Gravity

    Andrea Addazi🇨🇳 · Qingyu Gan🇮🇹

    We explore superoscillations within the context of classical and quantum field theories, presenting novel solutions to Klein-Gordon's, Dirac's, Maxwell's and Einstein's equations. In particular, we illustrate a procedure of second quantization of fields and how to construct a Fock space which encompasses Superoscillating states. Furthermore, we extend the application of superoscillations to quantum tunnelings, scatterings and mixings of particles, squeezed states and potential advancements in laser interferometry, which could open new avenues for experimental tests of Quantum Gravity effects. By delving into the relationship among superoscillations and phenomena such as Hawking radiation, the Black Hole (BH) information and the Firewall paradox, we propose an alternative mechanism for information transfer across the BH event horizon.

    ↳ hep-thgr-qchep-phquant-phEPJC(2024)·1 citation
33. 33*

    $\Lambda$ polarization in very high energy heavy ion collisions as a probe of the Quark-Gluon Plasma formation and properties

    Andrea Palermo🇺🇸 · Eduardo Grossi🇮🇹 · Iurii Karpenko🇨🇿 · Francesco Becattini🇮🇹

    We have studied the spin polarization of $\Lambda$ hyperons in heavy ion collisions at center-of-mass energies $\sqrt{s_{NN}}=200$ GeV and $\sqrt{s_{NN}}=5.02$ TeV carried out at RHIC and LHC colliders. We have calculated the mean spin vector at local thermodynamic equilibrium, including all known first-order terms in the gradients of the thermo-hydrodynamic fields, assuming that the hadronization hypersurface has a uniform temperature. We have also included the feed-down contributions to the polarization of $\Lambda$ stemming from the decays of polarized ${\Sigma }^{\ast }$ and ${\Sigma }^0$ hyperons. The obtained results are in good agreement with the data. In general, the component of the spin vector along the global angular momentum, orthogonal to the reaction plane, shows strong sensitivity to the initial longitudinal flow velocity. Furthermore, the longitudinal component of the spin vector turns out to be very sensitive to the bulk viscosity of the plasma at the highest LHC energy. Therefore, the azimuthal dependence of spin polarization can effectively constrain the initial hydrodynamic conditions and the transport coefficients of the Quark Gluon Plasma.

    ↳ nucl-thhep-phhep-thEPJC(2024)·47 citations
34. 34*

    Full Event Particle-Level Unfolding with Variable-Length Latent Variational Diffusion

    Alexander Shmakov🇺🇸 · Kevin Greif🇺🇸 · Michael James Fenton🇺🇸 · Aishik Ghosh🇺🇸 · Pierre Baldi🇺🇸 · Daniel Whiteson🇺🇸

    The measurements performed by particle physics experiments must account for the imperfect response of the detectors used to observe the interactions. One approach, unfolding, statistically adjusts the experimental data for detector effects. Recently, generative machine learning models have shown promise for performing unbinned unfolding in a high number of dimensions. However, all current generative approaches are limited to unfolding a fixed set of observables, making them unable to perform full-event unfolding in the variable dimensional environment of collider data. A novel modification to the variational latent diffusion model (VLD) approach to generative unfolding is presented, which allows for unfolding of high- and variable-dimensional feature spaces. The performance of this method is evaluated in the context of semi-leptonic top quark pair production at the Large Hadron Collider.

    ↳ hep-excs.AIcs.LGhep-phSciPost Phys.(2025)·26 citations
35. 35*

    Quantifying Scalar Field Dynamics with DESI 2024 Y1 BAO measurements

    Kim V. Berghaus🇺🇸 · Joshua A. Kable🇺🇸 · Vivian Miranda🇺🇸

    Quintessence scalar fields are a natural candidate for evolving dark energy. Unlike the phenomenological $w_0{w}_a$ parameterization of the dark energy equation of state, they cannot accommodate the phantom regime of dark energy $w(z)<-1$, or crossings into the phantom regime. Recent baryon acoustic oscillation (BAO) measurements by the Dark Energy Spectroscopic Instrument (DESI) indicate a preference for evolving dark energy over a cosmological constant, ranging from $2.6\sigma -3.9\sigma$ when fitting to $w_0{w}_a$, and combining the DESI BAO measurements with other cosmological probes. In this work, we directly fit three simple scalar field models to the DESI BAO data, combined with cosmic microwave background anisotropy measurements and supernova data sets. We find the best fit model to include a $2-4\%$ kinetic scalar field energy ${\Omega }_{\mathrm{scf},\mathrm{k}}$, for a canonical scalar field with a quadratic or linear potential. However, only the DESY-Y5 supernova data set combination shows a preference for quintessence over $\Lambda$CDM at the $95\%$ confidence level. Fitting to the supernova data sets Pantheon, Pantheon+, DES-Y5, and Union3, we show that the mild tension ($n_{\sigma }<3.4$) under $\Lambda$CDM emerges from a BAO preference for smaller values of fractional mass-energy density ${\Omega }_m<0.29$, while all supernova data sets, except for Pantheon, prefer larger values, ${\Omega }_m>0.3$. The tension under $\Lambda$CDM remains noticeable ($n_{\sigma }<2.8$), when replacing two of the DESI BAO redshift bins with effective redshifts $z_{\text{eff}}=0.51$, and $z_{\text{eff}}=0.706$ with comparable BOSS DR 12 BAO measurements at $z_{\text{eff}}=0.51$, and $z_{\text{eff}}=0.61$. Canonical scalar fields as dark energy are successful in mitigating that tension.

    ↳ astro-ph.COhep-phPRD(2024)·94 citations
36. 36*

    Wormholes in the axiverse, and the species scale

    Luca Martucci🇮🇹 · Nicolò Risso🇮🇹 · Alessandro Valenti🇨🇭 · Luca Vecchi🇮🇹

    We analyze a large class of four-dimensional $\mathcal{N}=1$ low-energy realizations of the axiverse satisfying various quantum gravity constraints. We propose a novel upper bound on the ultimate UV cutoff of the effective theory, namely the species scale, which only depends on data available at the two-derivative level. Its dependence on the moduli fields and the number $N$ of axions matches expectations from other independent considerations. After an assessment of the regime of validity of the effective field theory, we investigate the non-perturbative gravitational effects therein. We identify a set of axionic charges supported by extremal and non-extremal wormhole configurations. We present a universal class of analytic wormhole solutions, explore their deformations, and analyze the relation between wormhole energy scales and species scale. The connection between these wormholes and a special subclass of BPS fundamental instantons is discussed, and an argument in favor of the genericity of certain axion-dependent effective superpotentials is provided. We find a lower bound increasing with $N\gg 1$ on the Gauss-Bonnet coefficient, resulting in an exponential suppression of non-extremal wormhole effects. Our claims are illustrated and tested in concrete string theory models.

    ↳ hep-thhep-phJHEP(2024)·29 citations
37. 37*

    On possible embeddings of the standard model of particle physics and gravity in $E_8$

    Robert A. Wilson🇬🇧

    I investigate the structure of $E_8$ under the action of the subalgebra/subgroup $A_1+G_2+C_3$, as a potential route to unification of the fundamental forces of nature into a single algebraic structure. The particular real form $E_{8(-24)}$ supports a decomposition into compact $G_2$ plus split $A_1+C_3$, which allows a restriction from $G_2$ to $SU(3)$ for the strong force, together with split $S{L}_2(\mathbb{R})$ to break the symmetry of the weak interaction and give mass to the intermediate vector bosons. The factor $C_3$ contains various copies of the Lorentz group $S{L}_2(\mathbb{C})$ and extends the `spacetime' symmetries to the full group of symplectic symmetries of real $3+3$-dimensional phase space. Restricting $G_2$ to the Standard Model $SU(3)$ extends $C_3$ to $A_5$, in the real form $SU(3,3)$, acting on a complex phase space that includes both momentum and current. There is then a natural restriction from $SU(3,3)$ to $SO(3,3)$, describing the action of $S{L}_4(\mathbb{R})$ on phase space. The resulting action of $S{L}_4(\mathbb{R})$ on $E_8$ includes tensors that are equivalent to the stress-energy tensor, the Ricci tensor and the Riemann tensor, and therefore permits the formalism of general relativity to be developed inside $E_{8(-24)}$. The model then suggests unexpected and perhaps subtle ways in which general relativity and particle physics may be forced to modify each other, in order to produce a unified theory.

    ↳ physics.gen-phhep-ph2 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.