Tue·Jul 16, 2024Tuesday·July 16, 2024

1. 01*

   Generalized CP Symmetries in Three-Higgs-Doublet Models

   Iris Bree🇵🇹 · Duarte D. Correia🇵🇹 · Joao P. Silva🇵🇹

   We study the scalar and Yukawa sectors of three Higgs doublets models with a generalized CP symmetry. We show that there are only four classes of scalar potentials, merely one more than in two Higgs doublet models (2HDM). In 2HDM with generalized CP symmetries extended to the Yukawa sector, there are only two possible cases: the usual CP, with 18 real Yukawa couplings; and a minimal generalized CP model, with 12 real Yukawa parameters. In contrast, with three Higgs there is a rich variety of allowed models. We classify all possible Yukawa textures, showing that there are 40 possibilities, several of which have only 10 real Yukawa couplings.

   hep-phPRD(2024)·10 citations
2. 02*

   Excitations of the Higgs boson

   Gregory A. Wright🇺🇸

   In a simplified version of the standard model with a single quark doublet, I derive a transcendental equation for the complex Higgs boson mass. The equation involves a divergent integral which is regularized and renormalized conventionally. Setting the Higgs mass to its observed value, the decay width is narrow and within experimental limits. The mass equation has additional roots on other sheets in the complex energy plane. The first two are at 186 and 219 GeV. The lightest excitations are well defined though wider than the 125 GeV Higgs because decays to $W^{+}{W}^{-}$ and $ZZ$ are allowed.

   hep-phhep-th0 citations
3. 03*

   Simultaneous Extraction of the Weak Radius and the Weak Mixing Angle from Parity-Violating Electron Scattering on ${}^{12}\mathrm{C}$

   Matteo Cadeddu🇮🇹 · Nicola Cargioli🇮🇹 · Jens Erler🇩🇪 · Mikhail Gorchtein🇩🇪 · Jorge Piekarewicz🇺🇸 · Xavier Roca-Maza🇮🇹 · Hubert Spiesberger🇩🇪

   We study the impact of nuclear structure uncertainties on a measurement of the weak charge of ${}^{12}\mathrm{C}$ at the future MESA facility in Mainz. Information from a large variety of nuclear models, accurately calibrated to the ground-state properties of selected nuclei, suggest that a $0.3$% precision measurement of the parity-violating asymmetry at forward angles will not be compromised by nuclear structure effects, thereby allowing a world-leading determination of the weak charge of ${}^{12}\mathrm{C}$. Furthermore, we show that a combination of measurements of the parity-violating asymmetry at forward and backward angles for the same electron beam energy can be used to extract information on the nuclear weak charge distribution. We conclude that a $0.34$% precision on the weak radius of ${}^{12}\mathrm{C}$ may be achieved by performing a $3$% precision measurement of the parity-violating asymmetry at backward angles.

   hep-phnucl-thPRC(2024)·11 citations
4. 04*

   Influence of magnetic field-induced anisotropic gluon pressure during pre-equilibrium in heavy-ion collisions: A faster road towards isotropization

   A. Ayala🇲🇽 · A. Mizher🇧🇷

   Magnetic fields of a large intensity can be generated in peripheral high-energy heavy-ion collisions. Although their intensity drops fast and, moreover, it is not clear whether these fields last long enough to induce a magnetization during the quark-gluon plasma phase, most of the models and simulations predict a significant intensity that lasts up to proper times of order 1 fm after the beginning of the reaction, which is a typical time for the hydrodynamical phase to start. This interval of time is referred to as the pre-equilibrium stage. The evolution of the reaction during pre-equilibrium is thus likely to be influenced by these fields. In this work we adopt a strong field approximation to study the effects of the magnetic field-induced anisotropy on the gluon pressure. We include this anisotropy within the description obtained by means of Effective Kinetic Theory and explore the consequences to reach isotropization at proper times of order 1 fm. We show that when including the magnetic field effects, isotropization is achieved faster.

   hep-phhep-thnucl-thPRD(2024)·10 citations
5. 05*

   A progress in inverse matrix method in QCD sum rules

   Zhen-Xing Zhao🇨🇳 · Yi-Peng Xing🇨🇳 · Run-Hui Li🇨🇳

   In traditional QCD sum rules, the simple hadron spectral density model of ``delta-function-type ground state + theta-function-type continuous spectrum" determines that there is no perfect parameter selection. In recent years, inverse problem methods, especially the inverse matrix method, have shown better handling of QCD sum rules. This work continues to develop the inverse matrix method. Considering that the narrow-width approximation may still be a good approximation, we separate the contribution of the ground state from the spectral density. Then follow the general steps of the inverse matrix method to extract physical quantities such as decay constants that we are sometimes more interested in.

   hep-phEPJC(2024)·9 citations
6. 06*

   Dark energy from non-degenerate Higgs-vacuum

   Muhammad Usman🇵🇰 · Asghar Qadir🇵🇰

   Scalar fields are favorite among the possible candidates for the dark energy. Most frequently discussed are those with degenerate minima at $\pm {\varphi }_{min}$. In this paper, a slightly modified two-Higgs doublet model is taken to contain the Higgs field(s) as the dark energy candidate(s). The model considered has two non-degenerate minima at ${\varphi }_{\pm }$, instead of one degenerate minimum at $\pm {\varphi }_{min}$. The component fields of one SU(2) doublet (${\varphi }_1$) act as the standard model (SM) Higgs, while the component fields of the second doublet (${\varphi }_2$) are taken to be the dark energy candidates (lying in the true vacuum). It is found that one \emph{can} arrange for late time acceleration (dark energy) by using an SU(2) Higgs doublet, whose vacuum expectation value is zero, in the quintessential regime.

   hep-phgr-qcInt.J.Mod.Phys.D(2019)·1 citation
7. 07*

   Properties of neutron stars and strangeness-mixed stars from a pion mean-field approach

   Nam-Yong Ghim🇰🇷 · Hyun-Chul Kim🇰🇷 · Ulugbek Yakhshiev🇰🇷 · Ghil-Seok Yang🇰🇷

   We investigate the properties of the static neutron stars and strangeness-mixed stars, based on the equations of state derived from a pion mean-field approach. Using the empirical data on the pion-nucleus scattering and bulk properties of nuclear matter, we have already fixed all the parameters in a previous work, where the nucleons and hyperons were shown to be modified in various nuclear medium. In the current work, we first examine the energy and pressure inside a neutron star. We show that the central densities in various neutron stars vary within the range of $(3-4){\rho }_0$, where ${\rho }_0$ is the normal nuclear matter density. The mass-radius relations are obtained and discussed. As the slope parameter for neutron matter increases, the radii of the neutron stars increase with their masses fixed. We also study the strangeness-mixed stars or the hyperon stars using the same sets of the parameters. As the strangeness content of strange matter increases, the binding energy per nucleon is saturated and the corresponding equation of state becomes softened. Consequently, the central densities of the strangeness-mixed stars increase. Assuming that recently observed neutron stars are the strangeness-mixed ones, we find that the central densities increase.

   hep-phastro-ph.HEastro-ph.SRnucl-thPRD(2025)·0 citations
8. 08*

   Leptonic CP-violation in the sneutrino sector of the BLSSM with Inverse Seesaw

   Arindam Basu🇮🇳 · Amit Chakraborty🇮🇳 · Yi Liu🇬🇧 · Stefano Moretti🇬🇧 · Harri Waltari🇸🇪

   We study CP violation (CPV) in the sneutrino sector within the B-L extension of the Minimal Supersymmetric Standard Model (BLSSM), wherein an inverse seesaw mechanism has been implemented. CPV arises from the new superpotential couplings in the (s)neutrino sector, which can be complex and the mixing of CP-eigenstates induced by those couplings. CPV leads to asymmetries in so called T-odd observables, but we argue that such asymmetries also lead to a wider distribution of those observables. We look at a final state where a sneutrino decays to a lepton, two jets and missing transverse momentum at the Future Circular Collider operating in hadron-hadron mode at $100$ TeV and with a luminosity of 3 ab${}^{-1}$. In order to exclude the CP conserving scenario we need to improve traditional analysis by introducing boosted decision trees using both standard kinematic variables and T-odd observables and we need $Z^{\prime }$ boson not too much above current bounds as a portal to produce sneutrinos efficiently.

   hep-phhep-exPRD(2025)·1 citation
9. 09*

   Probing gluon saturation and nuclear structure in photon-nucleus collisions

   Heikki Mäntysaari🇫🇮 · Farid Salazar🇺🇸 · Björn Schenke🇺🇸 · Chun Shen🇺🇸 · Wenbin Zhao🇺🇸

   We calculate exclusive vector meson photoproduction within the Color Glass Condensate framework in high-energy photon-nucleus scattering probed experimentally in ultra peripheral heavy ion collisions at RHIC and at the LHC. When the free parameters are constrained by the $\gamma +p$ data from HERA, we predict significant nuclear suppression for both the coherent and incoherent photoproduction cross section in the TeV range. Our results indicate that the LHC data prefers even stronger saturation effects at the highest collision energies. Furthermore, we demonstrate how the linear polarization of photons in ulra peripheral collisions generates azimuthal modulations in the decay products of the exclusively produced vector meson. We show how these measurements can probe details of the nuclear geometry, specifically the deformed structure of the uranium nuclei.

   hep-phnucl-thPoS(2025)·1 citation
10. 10*

    The impact of data from future lepton colliders on light hadrons fragmentation functions

    Bin Zhou🇨🇳 · Jun Gao🇨🇳

    In this work, we study the constraining power of future lepton colliders on fragmentation functions (FFs) to light charged hadrons from quarks and gluon in the framework of QCD collinear factorization. We perform analyses of FFs at NLO by including a wide range of pseudo--data from future lepton colliders, such as measurements on hadron multiplicities in the production of two jets and $W$ boson pairs, at various center of mass energies, and from hadronic decays of the Higgs boson, including both to heavy quarks and to gluons. The high luminosity and high energies of future lepton colliders allow for quark flavor separations and ensure a precise determination of FFs based solely on data from electron-positron collisions. We find that either the CEPC, FCC-$ee$ or ILC can significantly reduce the uncertainties of FFs in a wide kinematic range, compared to the NPC23 set obtained with a global analysis to current world data. We also discuss the impact of higher-order QCD corrections, and the potential constraints from measurements of three-jet production. Furthermore, we describe an update of the FMNLO program allowing for calculating hadron production cross sections at next-to-next-to-leading order in QCD, which is used in this study.

    hep-phhep-exJHEP(2025)·11 citations
11. 11*

    Two-pion emission decays of negative parity singly heavy baryons

    Nongnapat Ponkhuha🇹🇭 · Ahmad Jafar Arifi🇯🇵 · Daris Samart🇹🇭

    We investigate two-pion emission decays of singly charmed and bottom baryons, focusing on ${\Lambda }_Q^{\ast }(1P)$ and ${\Xi }_Q^{\ast }(1P)$ with $Q=c$ (charm) or $b$ (bottom) quarks and $J^P=1/2^{-},3/2^{-}$, belonging to antisymmetric flavor triplet ${\bar{3}}_F$. Our analysis encompasses both sequential processes, involving intermediate states belonging to symmetric flavor sextet $6_F$ such as ${\Sigma }_Q(1S)$ and ${\Xi }_Q^{\prime }(1S)$ respectively with $J^P=1/2^{+},3/2^{+}$, derived from the chiral quark model, and direct process crucial for comparison with experimental data, whose coupling constants estimated using the chiral-partner scheme. We also incorporate the convolution of the parent particle's mass for the Dalitz plot, enabling a more realistic comparison with experimental data. We scrutinize the Dalitz plots of these negative parity states in light of recent Belle measurements for ${\Lambda }_c(2625{)}^{+}$. Our findings support the assignment of ${\Lambda }_c(2625{)}^{+}$ as the $\lambda$-mode excitation with $J^P=3/2^{-}$ in the quark model, deduced from the the ${\Lambda }_c\pi$ invariant mass distribution, and we then give predictions for other cases, including the ${\Xi }_Q^{\ast }$ decays. The observed asymmetry in the $\pi \pi$ invariant mass distribution underscores the important role of the direct process, reflecting the chiral-partner structure in the heavy baryon sector. It is evident that the presence of the direct process is not significant in the three-body decays unless the $S$-wave resonance contribution is suppressed. We suggest further experimental verification to test our predictions and get more insights into the structure of heavy baryons.

    hep-phnucl-thPRD(2024)·2 citations
12. 12*

    Gravitational wave signatures of first-order phase transition in two-component dark matter model

    Seyed Yaser Ayazi🇮🇷 · Mojtaba Hosseini🇮🇷 · Rouzbeh Rouzbehi🇮🇷

    Here, we consider a classically scale-invariant extension of the Standard Model (SM) with two-component dark matter (DM) candidates, including a Dirac spinor and a scalar DM. We probe the parameter space of the model, constrained by relic density and direct detection, and investigate the generation of gravitational waves (GWs) produced by an electroweak first-order phase transition. The analysis demonstrates that there are points in the parameter space, leading to a detectable GW spectrum arising from the first-order phase transition, which is also consistent with the DM relic abundance and direct detection bounds. These GWs could be observed by forthcoming space-based interferometers such as the Big Bang Observer, Decihertz Interferometer Gravitational-wave Observatory, and Ultimate-Decihertz Interferometer Gravitational-wave Observatory.

    hep-phastro-ph.COPRD(2024)·8 citations
13. 13*

    Understanding the non-trivial isoscalar pseudoscalar structures in the $K_S{K}_S{\pi }^0$ spectra in the $J/\psi$ radiative decay

    Yin Cheng🇨🇳 · Lin Qiu🇨🇳 · Qiang Zhao🇨🇳

    Initiated by the recent observation of a flattened lineshape of $I{J}^{PC}=00^{-+}$ around $1.4\sim 1.5$ GeV in the $K_S{K}_S{\pi }^0$ invariant mass spectrum by BESIII, we make a systematic partial wave analysis of $J/\psi \to \gamma {\eta }_X\to \gamma K\bar{K}\pi$ based on an isobaric approach. We demonstrate that in the scenario of the first radial excitations of the isoscalar pseudoscalar from the $K\bar{K}\pi$ threshold to about 1.6 GeV the non-trivial $K_S{K}_S{\pi }^0$ invariant mass spectrum can be explained by the coupled-channel effects with the presence of the triangle singularity mechanism. It shows that a combined fit of the Dalitz plots, three-body and two-body spectra can be achieved which suggests that the one-state solution around $1.4\sim 1.5$ GeV proposed before still holds well. In particular, we show that the coupled-channel effects between the three important quasi-two-body decay channels, $K^{\ast }\bar{K}+c.c.$, $\kappa \bar{K}+c.c.$ and $a_0(980)\pi$, can be well described by taking into account the one-loop corrections in the isobaric approach. This is because the isoscalar pseudoscalar states are coupled to the $K^{\ast }\bar{K}+c.c.$ and $a_0(980)\pi$ ($\kappa \bar{K}+c.c.$) channels via the $P$ and $S$ waves, respectively. As a consequence, the coupled-channel effects can be largely absorbed into the redefinition of the tree-level effective couplings with the transition amplitudes computed to the order of one-loop corrections. Then, the coupled-channel effects can be estimated by the contributions from the one-loop rescattering amplitudes in comparison with the tree-level ones, where we find that the rescattering contributions from the $P$-wave into the $S$-wave, or vice verse, are apparently suppressed in the kinematic region near threshold.

    hep-phPRD(2025)·4 citations
14. 14*

    Gravitational form factors of pseudoscalar mesons in a contact interaction

    M. Atif Sultan🇨🇳 · Zanbin Xing🇨🇳 · Khépani Raya🇪🇸 · Adnan Bashir🇲🇽 · Lei Chang🇨🇳

    Given the unique role played by the gravitational form factors (GFFs) in unraveling the internal mechanics of hadrons, we examine the GFFs of ground state pseudoscalar mesons $\pi$, ${\eta }_c$, ${\eta }_b$ and the hypothetical {\em strangeonium} ${\eta }_s(s\bar{s})$. We adopt the coupled framework of Dyson-Schwinger and Bethe-Salpeter equations within a contact interaction, and employ a novel approach to the dressed amputated meson-meson scattering amplitude which makes connection with the energy-momentum tensor and with the GFFs. The resulting GFFs fulfill the anticipated symmetry constraints. The corresponding charge and mass radii and the $D-$term are also computed. We show that the $D-$term for the pseudoscalar mesons is bounded within the $(-1,-1/3)$ range; these bounds correspond to the massless (chiral limit) and infinitely massive cases, respectively. Considering the current interest in the GFFs, understanding the \textit{D}-term of pseudoscalar mesons and their GFFs can provide an important first step for future endeavors in the field.

    hep-phPRD(2024)·25 citations
15. 15*

    Investigation on the stabilities of doubly heavy tetraquark states

    Woosung Park🇰🇷 · Sungsik Noh🇰🇷

    In our recent work\cite{Noh:2023zoq}, the mass and binding energy of $T_{cc}$ are found to be $3873$ MeV and $-2$ MeV, respectively, which align with the observations reported at LHCb\cite{LHCb:2021vvq}. Based on our latest quark model approach, we extend our search for other potentially stable configurations of doubly heavy tetraquarks using our nonrelativistic quark model described in Ref.~\cite{Noh:2023zoq}. Our numerical calculations indicate that the $\bar{u}\bar{s}cb$ configuration is deeply bound. However, the $\bar{u}\bar{d}cb$ configuration with the isospin symmetry in the light quark sector is relatively less bound. In this study, we emphasize a compulsory aspect for requiring a complete set of three dimensional harmonic oscillator bases through the discussion of the $\bar{u}\bar{s}cb$ configuration and investigate the essential differences between the $\bar{u}\bar{s}cb$ and $\bar{u}\bar{d}cb$ configurations.

    hep-phPRD(2024)·4 citations
16. 16*

    Contribution to the Proton Spin Puzzle from Helicity at small Bjorken $x$

    Yossathorn Tawabutr🇫🇮

    The contribution to proton helicity from the spins of quarks and gluons at small Bjorken $x$ can be conveniently studied through the small-$x$ helicity evolution. Recently, it has been employed in a global analysis that includes polarized inclusive and semi-inclusive deep-inelastic scattering measurements at small $x$. The analysis demonstrates an excellent agreement between the evolution and the data, but its predictions contain large uncertainties owing to the large number of free parameters in the initial conditions. The latest development aims to mitigate this issue by employing the valence quark model in the polarized proton target in order to replace most of the free parameters in the initial conditions by the physical information from the proton model.

    hep-phPoS(2025)·1 citation
17. 17*

    3D structure of hadrons and energy-momentum tensor

    Cédric Lorcé (Ecole Polytechnique)🇫🇷

    The three-dimensional spatial structure of hadrons is encoded in their form factors. Via appropriate Fourier transform, the latter describe how charge, energy, linear and angular momentum, but also pressure are distributed inside these systems. Electromagnetic form factors of the nucleon have been measured for a long time, but it is only recently that some gravitational form factors have been extracted from experimental data, creating a great deal of enthusiasm in the hadronic community. Here we summarize some of the recent developments on the interpretation of these form factors, and provide a quick overview of what we can learn about the nucleon mass, spin and internal pressure.

    hep-phnucl-thPoS(2025)·1 citation
18. 18*

    Confronting the low-scale seesaw and leptogenesis with neutrinoless double beta decay

    J. de Vries🇳🇱 · M. Drewes🇧🇪 · Y. Georis🇧🇪 · J. Klarić🇧🇪 · V. Plakkot🇳🇱

    We revisit the impact of heavy neutrinos with masses in the MeV-GeV range on neutrinoless double beta decay ($0\nu \beta \beta$) in view of updated results for the lifetime of this process. Working in a minimal realistic extension of the Standard Model by two right-handed neutrino flavours, we show that the non-observation of $0\nu \beta \beta$ will impose strong bounds on the heavy neutrino properties that are complementary to the limits obtained from Big Bang Nucleosynthesis and collider searches. For an inverted mass hierarchy of the light neutrinos we find that improved limits on $0\nu \beta \beta$ from next-generation experiments, assuming an improvement of two orders of magnitude on the current $0\nu \beta \beta$ limits will restrict the allowed parameter space for fixed mass splitting to narrow bands in the mass-mixing plane. Further combining this with the requirement to explain the baryon asymmetry of the universe via leptogenesis reduces these bands to windows in parameter space that are constrained in all directions and can be targeted by direct searches at accelerators, and restricts the mass splitting to values that can be resolved at experiments. For a normal mass hierarchy, restricting the allowed parameter will require even stronger $0\nu \beta \beta$ limits, and only parts of the parameter space can then be probed.

    hep-phastro-ph.COnucl-thJHEP(2025)·25 citations
19. 19*

    Bayesian approach to determine the initial condition for the Balitsky-Kovchegov equation

    Carlisle Casuga🇫🇮 · Mikko Karhunen🇫🇮 · Heikki Mäntysaari🇫🇮

    We present posterior distributions of parameters that characterize the nonperturbative initial input for the Balitsky-Kovchegov evolution equation. The BK equation evolves an initial dipole-target scattering amplitude at moderate $x_{\mathrm{Bj}}$ values toward smaller values. We use Bayesian inference to constrain the model parameters against the precise combined reduced cross section data from HERA, and obtain probability distributions for the free parameters. Our results show the data's preference for the anomalous dimension to be $\gamma \sim 1$. The distributions provide a rigorous method for propagating uncertainties of the BK initial condition for other CGC calculations. We demonstrate this for inclusive quark production in proton-proton collisions and nuclear modification factor for the total deep inelastic scattering cross section to be measured at the EIC.

    hep-phPoS(2025)·0 citations
20. 20*

    Muon-induced collisional flavor instability in core-collapse supernova

    Jiabao Liu🇯🇵 · Hiroki Nagakura🇯🇵 · Ryuichiro Akaho🇯🇵 · Akira Ito🇯🇵 · Masamichi Zaizen🇯🇵 · Shun Furusawa🇯🇵 · Shoichi Yamada🇯🇵

    Neutrinos are known to undergo flavor conversion among their three flavors. In the theoretical modeling of core-collapse supernova (CCSN), there has been a great deal of attention to recent discoveries of a new type of neutrino flavor conversions, namely collisional flavor instability (CFI), in which the instability is induced by the flavor-dependent decoherence due to the disparity of neutrino-matter interactions among flavors. In this paper, we study how the appearance of on-shell muons and associated neutrino-matter interactions can impact CFIs based on linear stability analysis of flavor conversions. Some striking results emerge from the present study. First, we analytically show that breaking beta- and pair equilibrium is a necessary condition to trigger CFIs. This also indicates that CFIs with on-shell muons could appear in $e\tau$ and $\mu \tau$ neutrino mixing sectors in very high-density region ($\gtrsim 10^{13}g/c{\mathrm{m}}^3$), exhibiting a possibility of large impacts of CFIs on CCSN. Second, resonance-like CFIs, having a much higher growth rate than normal CFIs, can be triggered by muons. The resonance point of CFIs is different between $e\tau$ and $\mu \tau$ sectors; the former (latter) occurs at ${\mu }_{e(\mu )}={\mu }_n-{\mu }_p$, where ${\mu }_i$ denotes the chemical potential of $i$ constitute ($n$ and $p$ represent neutrons and protons, respectively). Our result suggests that the non-linear evolution of CFI with on-shell muons would induce flavor conversions with the complex interplay among all three different neutrino-mixing sectors.

    hep-phastro-ph.HEPRD(2024)·15 citations
21. 21*

    Dual symmetries of dense isotopically and chirally asymmetric QCD

    K. G. Klimenko🇷🇺 · R. N. Zhokhov🇷🇺

    In the present paper, the dual symmetries of dense quark matter phase diagram found in some massless three- and two-color NJL models in the mean field approximation have been shown to exist at a more fundamental level as a dual transformations of fields and chemical potentials leaving the Lagrangian invariant. As a result, the corresponding dual symmetries of the full phase diagram can be shown without any approximation. And it has been shown not only in the NJL models, but also in framework of two- and three-color massless QCD itself. This is quite interesting, since one might say that it is not very common to show something completely non-perturbatively in QCD.

    hep-phhep-thEPJC(2024)·5 citations
22. 22*

    Classification of Coupled-Channel Near-Threshold Structures

    Zhen-Hua Zhang🇨🇳 · Feng-Kun Guo🇨🇳

    Since 2003, plenty of resonant structures have been observed in the heavy quarkonium regime. Many of them are close to the thresholds of a few pairs of heavy hadrons. They are candidates of exotic hadrons and have attracted immense attentions. Based on a coupled-channel nonrelativistic effective field theory, we classify the near-threshold structures of a symmetry-related two-channel system by studying the evolution of the scattering amplitude line shapes and pole positions with the variation of the single-channel scattering length and channel coupling strength. We show that the evolution of the scattering amplitude line shapes can be understood from the pole trajectories in the complex energy plane, and the pole evolution can be traced back to the renormalization group fixed points. We provide a dictionary of correspondence between the evolution of line shapes and pole trajectories along with varying interaction and channel coupling strengths, which can be used to understand the experimental observations of the near-threshold structures.

    hep-phhep-exnucl-thPLB(2025)·26 citations
23. 23*

    Global analysis of nuclear parton distribution functions

    M. Klasen🇩🇪

    We review the theoretical foundations, methodological approaches and current status of the determination of nuclear parton distribution functions (PDFs). A large variety of measurements in fixed-target and collider experiments provide increasingly precise constraints on various aspects of nuclear PDFs, including shadowing, antishadowing, the EMC effect, Fermi motion, flavour separation, deuteron binding, target-mass and other higher-twist effects. We give particular emphasis to measurements carried out in proton-lead collisions at the Large Hadron Collider, which have revolutionised the global analysis during the past decade. These measurements include electroweak boson, isolated photon, single inclusive hadron, jet, and heavy-flavour observables.

    hep-phhep-exnucl-exnucl-thPoS(2025)·2 citations
24. 24*

    A phenomenological investigation of the beauty content of a proton in the framework of $k_t$-factorization using KMR and MRW unintegrated parton distributions

    Naeimeh Olanj🇮🇷

    In this paper, we address the reduced beauty cross section (${{\sigma }_{red}}^{b\overline{b}}(x,Q^2)$) and the beauty structure function (${F_2}^{b\overline{b}}(x,Q^2)$), to study the beauty content of a proton. We calculate ${{\sigma }_{red}}^{b\overline{b}}$ and ${F_2}^{b\overline{b}}$ in the $k_t$-factorization formalism by using the integral form of the Kimber-Martin-Ryskin and Martin-Ryskin-Watt unintegrated parton distribution function with the angular ordering constraint ($AOC$) and the MMHT2014 PDF set as the input. Recently Guiot and van Hameren demonstrated that the upper limit, $K_{max}$, of the transverse-momentum integration performed in the $k_t$-factorization formalism should be almost equal to Q, where Q is the hard scale, otherwise it leads to an overestimation of the proton structure function ($F_2(x,Q^2)$). In the present work, we show that $k_{max}$ cannot be equal Q at low and moderate energy region, and also by considering the gluon and quark contributions to the same perturbative order and a physical gauge for the gluon, i. e., $A^{\mu }{q}_{\mu }^{\prime }=0$ in the calculation of ${F_2}^{b\overline{b}}$ in the $k_t$-factorization formalism, we do not encounter any overestimation of the theoretical predictions due to different choices of $K_{max}>Q$. Finally, the resulted ${{\sigma }_{red}}^{b\overline{b}}$ and ${F_2}^{b\overline{b}}$ are compared to the experimental data and the theoretical predictions. In general, the extracted ${{\sigma }_{red}}^{b\overline{b}}$ and ${F_2}^{b\overline{b}}$ based on the KMR and MRW approaches are in perfect agreement with the experimental data and theoretical predictions at high energies, but at low and moderate energies, the one developed from the KMR approach has better consistency than that of MRW approach.

    hep-phPRD(2024)·3 citations
25. 25*

    The infamous 95 GeV $\mathrm{b}\bar{\mathrm{b}}$ excess at LEP: Two b or not two b?

    Patrick Janot🇨🇭

    A small deviation observed around 95 GeV in the diphoton invariant mass distribution in the LHC Run 2 data has been subject to considerable attention in the past couple of years. The interpretation of this excess as the manifestation of an additional scalar particle at this mass is often claimed to be supported by a previously observed, even smaller, excess in the bb̄ invariant mass distribution in LEP data. This short note aims at confronting this claim to factual experimental observations, through a careful scrutiny of the detailed LEP public notes written at the time on the topic. It is found that the LEP data strongly disfavour the production of a new 95 GeV scalar particle, as well as any other new physics interpretation in the 95-100 GeV mass range.

    hep-phhep-exJHEP(2024)·13 citations
26. 26*

    Flavour Deconstructing the Composite Higgs

    Sebastiano Covone🇨🇭 · Joe Davighi🇨🇭 · Gino Isidori🇨🇭 · Marko Pesut🇨🇭

    We present a flavour non-universal extension of the Standard Model combined with the idea of Higgs compositeness. At the TeV scale, the gauge groups $SU(2{)}_R$ and $U(1{)}_{B-L}$ are assumed to act in a non-universal manner on light- and third-generation fermions, while the Higgs emerges as a pseudo Nambu-Goldstone boson of the spontaneous global symmetry breaking $Sp(4)\to SU(2{)}_L\times SU(2{)}_R^{[3]}$, attributed to new strong dynamics. The flavour deconstruction means the couplings of the light families to the composite sector (and therefore the pNGB Higgs) are suppressed by powers of a heavy mass scale (from which the Higgs is nevertheless shielded by compositeness), explaining the flavour puzzle. We present a detailed analysis of the radiatively generated Higgs potential, showing how this intrinsically-flavoured framework has the ingredients to justify the unavoidable tuning in the Higgs potential necessary to separate electroweak and composite scales. This happens for large enough values of the $SU(2{)}_R^{[3]}$ gauge coupling and light enough flavoured gauge bosons resulting from the deconstruction, whose phenomenology is also investigated. The model is compatible with current experimental bounds and predicts new states at the TeV scale, which are within the reach of near future experimental searches.

    hep-phJHEP(2025)·27 citations
27. 27*

    A Nuclear Interferometer for Ultra-Light Dark Matter Detection

    Hannah Banks🇬🇧 · Elina Fuchs🇩🇪 · Matthew McCullough🇨🇭

    We propose the nuclear interferometer - a single-photon interferometry experiment based upon the thorium-229 nuclear clock transition - as a novel detector for ultra-light dark matter. Thanks to the enhanced sensitivity of this transition to the variation of fundamental constants, we find that possible realisations of such an experiment deploying either single ions or clouds of atoms have the potential to complement advanced very-long-baseline terrestrial clock atom interferometers in the search for ultra-light dark matter with scalar couplings to photons in the future. Nuclear interferometry may also offer an unparalleled window to new physics coupling to the QCD sector via quarks or gluons, with a discovery reach that could enhance existing and proposed experiments over a range of frequencies in the direction of well-motivated parameter space.

    hep-phhep-exnucl-exphysics.atom-phPRD(2026)·6 citations
28. 28*

    Q-Balls in the presence of attractive force

    Yu Hamada🇩🇪 · Kiyoharu Kawana🇰🇷 · TaeHun Kim🇰🇷 · Philip Lu🇰🇷

    Q-balls are non-topological solitons in field theories whose stability is typically guaranteed by the existence of a global conserved charge. A classic realization is the Friedberg-Lee-Sirlin (FLS) Q-ball in a two-scalar system where a real scalar $\chi$ triggers symmetry breaking and confines a complex scalar $\Phi$ with a global $U(1)$ symmetry. A quartic interaction $\kappa {\chi }^2|\Phi {|}^2$ with $\kappa >0$ is usually considered to produce a nontrivial Q-ball configuration, and this repulsive force contributes to its stability. On the other hand, the attractive cubic interaction $\Lambda \chi |\Phi {|}^2$ is generally allowed in a renormalizable theory and could induce an instability. In this paper, we study the behavior of the Q-ball under the influence of this attractive force which has been overlooked. We find approximate Q-ball solutions in the limit of weak and moderate force couplings using the thin-wall and thick-wall approximations respectively. Our analytical results are consistent with numerical simulations and predict the parameter dependencies of the maximum charge. A crucial difference with the ordinary FLS Q-ball is the existence of the maximum charge beyond which the Q-ball solution is classically unstable. Such a limitation of the charge fundamentally affects Q-ball formation in the early Universe and could plausibly lead to the formation of primordial black holes.

    hep-phastro-ph.COhep-thJHEP(2024)·6 citations
29. 29*

    A Simplified Model of Heavy Vector Singlets for the LHC and Future Colliders

    Michael J. Baker🇺🇸 · Timothy Martonhelyi🇺🇸 · Andrea Thamm🇺🇸 · Riccardo Torre🇮🇹

    We study a simplified model of two colourless heavy vector resonances in the singlet representation of $SU(2{)}_L$, with zero and unit hypercharge. We discuss mixing with the Standard Model gauge bosons due to electroweak symmetry breaking, semi-analytic formulae for production at proton colliders, requirements to obey the narrow width approximation and selected low energy constraints. We show current LHC constraints and sensitivity projections for the HL-LHC, HE-LHC, SPPC and FCC-hh on the charged and neutral heavy vectors. The utility of the simplified model Lagrangian is demonstrated by matching these results onto three explicit models: a weakly coupled abelian extension of the Standard Model gauge group, a weakly coupled non-abelian extension and a strongly coupled minimal composite Higgs model. All our results are presented in terms of physical resonance masses, using expressions which are accurate even at vector masses near the electroweak scale due to a parameter inversion we derive. We discuss the importance of this inversion and point out that its effect, and the effects of electroweak symmetry breaking, can remain important up to resonance masses of several TeV. Finally, we clarify the relation between this simplified model and the Heavy Vector Triplet (HVT) model, a simplified model for heavy $SU(2{)}_L$ triplets with zero hypercharge, and provide exact and approximate matching relations.

    hep-phhep-exJHEP(2025)·7 citations
30. 30*

    Detection of hidden emissions in two rotating radio transients with high surface magnetic fields

    S.B. Zhang🇨🇳 · X. Yang🇨🇳 · J.J. Geng🇨🇳 · Y.P. Yang🇨🇳 · X.F. Wu🇨🇳

    Rotating Radio Transients (RRATs) are neutron stars emitting sporadic radio pulses. The unique emission of RRATs has been proposed to resemble those of known pulsar types, such as extreme nulling pulsars or pulsars with giant pulses. However, the presence of additional radiation beyond these sporadic pulses remains unclear. Through high-sensitivity observations and extended tracking, we detected the sequential weak emissions in two RRATs with relatively high surface magnetic fields (Bs > 10^13 G): J1846-0257 and J1854+0306. These emissions show peak flux densities of 0.15 and 0.41 mJy, up to 687 and 512 times weaker than our detected RRAT single pulses, respectively. The weak emissions contribute small fractions (~ 16% and 5%) to the total radio pulse energy releases, contrasting significantly with giant-pulse pulsars where normal pulses dominate. Polarization analysis of J1854+0306 suggests that its sporadic RRAT pulses may originate from intermittent enhanced sparking processes due to magnetospheric evolution. Our findings indicate that some RRATs may represent a novel class of pulsars, distinct from any previously known subclass. Further observations of sources with similar rotational properties using high-sensitivity instruments could validate the generality of these hidden emissions.

    ↳ astro-ph.HEhep-phApJL(2024)·5 citations
31. 31*

    Incoherent solar-neutrino scattering off the stable Tl-isotopes

    Dimitrios K. Papoulias🇬🇷 · Matti Hellgren🇫🇮 · Jouni Suhonen🇫🇮

    Nuclear-structure calculations for the description of low-energy neutral-current neutrino scattering off the stable ${}^{203,205}$Tl isotopes are performed in the context of the nuclear shell model using the model space jj56pn. Cross-section and event-rate calculations focusing on inelastic solar-neutrino scattering off ${}^{203,205}$Tl are performed. The individual contributions of the various nuclear responses are presented and discussed, and the results are also illustrated in terms of the nuclear recoil energy. Analytical expressions entering the cross sections are given in order to achieve a direct connection with experimental observables.

    ↳ nucl-thhep-phPRC(2024)·4 citations
32. 32*

    Threshold photo-production of $J/\Psi$ off light nuclei

    Fangcheng He🇺🇸 · Ismail Zahed🇺🇸

    We analyze threshold photoproduction of heavy mesons off a deuteron and Helium-4, using the QCD factorization method. Assuming large skewness, the production amplitude is dominated by the leading twist-2 gluonic energy-momentum tensor (EMT). We use our recent results for the gluonic gravitational form factors of light nuclei in the impulse approximation, to estimate the differential cross sections for $J/\Psi$ production off a deuteron and Helium-4 at current electron facilities.

    ↳ nucl-thhep-phPRC(2025)·4 citations
33. 33*

    Personal Reminiscences of Steven Weinberg

    Fernando Quevedo🇬🇧

    My personal recollections are presented regarding my interactions with Steven Weinberg and the impact he had in my career from when I was his graduate student until the present.

    ↳ physics.hist-phhep-phhep-thNPB(2024)·0 citations
34. 34*

    Charged hadron spectra and anisotropic flow from the AMPT model with shear viscous transport dynamics simulations at RHIC

    Yao Zhang🇨🇳

    We utilized the AMPT model to simulate the shear viscous transport dynamics of parton matter in Au+Au collisions at a constant specific shear viscosity and varying phase transition temperatures at 200 GeV. The resulting charged hadron spectra and anisotropic flow profiles correspond closely with experimental data. The transverse momentum spectra and longitudinal decorrelations are essentially unaffected by the phase transition temperature. An increase in the phase transition temperature leads to a rise in particle yields at midrapidity, accompanied by a decrease in both elliptic and triangular flows over a range of transverse momenta and pseudorapidities.

    ↳ nucl-thhep-phEPJA(2025)·5 citations
35. 35*

    Search for Dark Matter Annihilation to gamma-rays from SPT-SZ selected Galaxy Clusters

    Siddhant Manna🇮🇳 · Shantanu Desai🇮🇳

    We search for dark matter annihilation from galaxy clusters in the energy range from 1-300 GeV using nearly 16 years of Fermi-LAT data. For this purpose, we use 350 galaxy clusters selected from the 2500 $\mathrm{de}{\mathrm{g}}^2$ SPT-SZ survey. We model the dark matter distribution using the NFW profile for the main halo along with the Einasto profile for the substructure. The largest signal is seen for the cluster SPT-CL J2021-5257 with a significance of around $3\sigma$. The best-fit dark matter mass and annihilation cross-section for this cluster are equal to $(60.0\pm 11.8)$ GeV and $⟨\sigma v⟩=(6.0\pm 0.6)\times 10^{-25}\mathrm{c}{\mathrm{m}}^3{\mathrm{s}}^{-1}$ for the $\bar{b}b$ annihilation channel. However, this central estimate is in conflict with the limits on annihilation cross-section from dwarf spheroidal galaxies, and hence cannot be attributed to dark matter annihilation. Three other clusters show significance between $2-2.5\sigma$, whereas all the remaining clusters show null results. The most stringent 95\% c.l. upper limit for the WIMP annihilation cross-section among all the clusters is from SPT-CL J0455-4159, viz. $⟨\sigma v⟩=6.44\times 10^{-26}{\text{cm}}^3{\text{s}}^{-1}$ for $m_{\chi }=10$ GeV and $b\bar{b}$ annihilation channel.

    ↳ astro-ph.COastro-ph.HEhep-phJCAP(2024)·4 citations
36. 36*

    A Semi-Empirical Formula for Two-Neutrino Double-Beta Decay

    Ovidiu Niţescu🇸🇰 · Fedor Šimkovic🇸🇰

    We propose a semi-empirical formula (SEF) for calculating the nuclear matrix elements (NMEs) for two-neutrino double-beta decay. The SEF's dependence on the proton and neutron numbers, the pairing, isospin, and deformation properties of the initial and final nuclei is inspired by the insights offered by nuclear many-body methods and trends in experimental data. Compared with the previous phenomenological and nuclear models, the SEF yields the best agreement with the experimental NMEs. Its stability and predictive power are cross-validated, and predictions are provided for nuclear systems of experimental interest.

    ↳ nucl-thhep-phPRC(2025)·4 citations
37. 37*

    Polarized $\varphi$ meson rates with viscous corrections at RHIC

    Eduardo Grossi🇮🇹 · Andrea Palermo🇺🇸 · Ismail Zahed🇺🇸

    We discuss the emission of $\varphi$ mesons with longitudinal and transverse polarization in ultra-relativistic heavy ion collisions. In the hadronic phase and in leading order in the kaon diluteness, $\varphi$ emission is isotropic and driven by the flavor singlet and octet vector spectral functions. At next to leading order, the emissivities receive a non-isotropic correction from the flavor octet spectral function, and the non-equilibrium contributions originating from the shear and bulk viscosities. Implications for the $\varphi$ meson alignment in heavy-ion collisions are discussed.

    ↳ nucl-thhep-phPRC(2025)·10 citations
38. 38*

    Probing QGP droplets with charmonium in high-multiplicity proton-proton collisions

    Yunfan Bai🇬🇧 · Baoyi Chen🇨🇳

    We study the hot medium effects in high-multiplicity proton-proton (pp) collisions at $\sqrt{s_{NN}}=13$ TeV via the charmonium probes. The hot medium is described with the hydrodynamic model, while charmonium evolutions in the medium are studied with a time-dependent Schrödinger equation. The hot medium dissociation on charmonium is considered with the temperature-dependent complex potential parametrized with the results from lattice QCD calculations. The ratio ${\sigma }_{\psi (2S)}/{\sigma }_{J/\psi }$ of $J/\psi$ and $\psi (2S)$ production cross sections are calculated and compared with the LHCb experimental data in pp collisions. Our calculations explain the charmonium relative suppression in different transverse momentum and multiplicity bins. The suppression of this ratio is mainly affected by the effects of the deconfined medium. It is less affected by the initial effects before the generation of the heavy quark pair. We suggest this to be a clear signal of the small QGP droplets generated in high multiplicity pp collisions.

    ↳ nucl-thhep-phEPJC(2024)·8 citations
39. 39*

    Comparing matching prescriptions between pre-equilibrium and hydrodynamic models in high-energy nuclear collisions

    Nicolas Borghini🇩🇪 · Renata Krupczak🇩🇪 · Hendrik Roch🇺🇸

    State-of-the-art simulations of high-energy nuclear collisions rely on hybrid setups, involving in particular a pre-equilibrium stage to let the system evolve from a far-from-equilibrium initial condition towards a near-equilibrated state after which fluid dynamics can be applied meaningfully. A known issue is the mismatch between the equation of state in the fluid-dynamical evolution and the effective one in the previous stage, which leads to discontinuities at the interface between the two models. Here we introduce a new matching prescription at this interface, based on the entropy, and we compare it with the standard one relying on local energy conservation. We study the behavior of various quantities at the switching time between the models and investigate a number of final-state hadronic observables. For the latter, we show that they are not modified significantly by the choice of matching prescription, provided an appropriate normalization is chosen for the initial state. In turn, our approach reduces sizeably the ratio of bulk over thermodynamic pressure at the beginning of the fluid-dynamical stage.

    ↳ nucl-thhep-phEPJC(2024)·5 citations
40. 40*

    Vacuum energy density from the form factor bootstrap

    André LeClair🇺🇸

    The form-factor bootstrap is incomplete until one normalizes the zero-particle form factor. For the stress energy tensor we describe how to obtain the vacuum energy density ${\rho }_{\mathrm{vac}}$, defined as $⟨0|T_{\mu \nu }|0⟩={\rho }_{\mathrm{vac}}{g}_{\mu \nu }$, from the form-factor bootstrap. Even for integrable QFT's in D=2 spacetime dimensions, this prescription is new, although it reproduces previously known results obtained in a different and more difficult thermodynamic Bethe ansatz computation. We propose a version of this prescription in D=4 dimensions. For these even dimensions, the vacuum energy density has the universal form ${\rho }_{\mathrm{vac}}\propto m^D/\mathfrak{g}$ where $\mathfrak{g}$ is a dimensionless interaction coupling constant which can be determined from the high energy behavior of the S-matrix. In the limit $\mathfrak{g}\to 0$, ${\rho }_{\mathrm{vac}}$ diverges due to well understood UV divergences in free quantum field theories. If we assume the the observed Cosmological Constant originates from the vacuum energy density ${\rho }_{\mathrm{vac}}$ computed as proposed here, then this suggests there must exist a particle which does not obtain its mass from spontaneous symmetry breaking in the electro-weak sector, which we designate as the "zeron". A strong candidate for the zeron is a massive Majorana neutrino.

    ↳ hep-thhep-phmath-phmath.MPJHEP(2024)·1 citation
41. 41*

    Hybrid calculation of hadronic vacuum polarization in muon g-2 to 0.48\%

    A.Boccaletti🇩🇪 · Sz.Borsanyi🇩🇪 · A.Cotellucci🇩🇪 · M.Davier🇫🇷 · Z.Fodor🇩🇪 · F.Frech🇩🇪 · A.Gerardin🇫🇷 · D.Giusti🇩🇪 · A.Yu.Kotov🇩🇪 · L.Lellouch🇫🇷 · Th.Lippert🇩🇪 · A.Lupo🇫🇷 and 10 other authors

    We present a new lattice QCD calculation of the leading order hadronic vacuum polarization (LO-HVP) contribution to the muon anomalous magnetic moment $a_{\mu }$. We reduce uncertainties compared to our earlier computation arXiv:2002.12347 by a factor of 1.6. We perform simulations on finer lattices allowing for an even more accurate continuum extrapolation. We also include a small, long-distance contribution obtained using input from experiments in a low-energy regime where they all agree. Combined with other standard model contributions our result, $a_{\mu }^{LO-HVP}=715.1(2.5)(2.3)[3.4]\times 10^{-10}$, leads to a prediction that differs from the recent measurement of $a_{\mu }$ by only 0.5 standard deviations. This provides a remarkable validation of the standard model to 11 digits.

    ↳ hep-lathep-phhep-thNature(2026)·189 citations
42. 42*

    Benchmarking neutrino interaction models via a comparative analysis of kinematic imbalance measurements from the T2K, MicroBooNE and MINERvA experiments

    Wissal Filali🇨🇭 · Laura Munteanu🇨🇭 · Stephen Dolan🇨🇭

    Recent neutrino-nucleus cross-section measurements of observables characterising kinematic imbalance from the T2K, MicroBooNE and MINERvA experiments are used to benchmark predictions from widely used neutrino interaction event generators. Given the different neutrino energy spectra and nuclear targets employed by the three experiments, comparisons of model predictions to their measurements breaks degeneracies that would be present in any single measurement. In particular, the comparison of T2K and MINERvA measurements offers a probe of energy dependence, whilst a comparison of T2K and MicroBooNE investigates scaling with nuclear target. In order to isolate the impact of individual nuclear effects, model comparisons are made following systematic alterations to: the nuclear ground state; final state interactions and multi-nucleon interaction strength. The measurements are further compared to the generators used as an input to DUNE/SBN and T2K/Hyper-K analyses. Whilst no model is able to quantitatively describe all the measurements, evidence is found for mis-modelling of A-scaling in multi-nucleon interactions and it is found that tight control over how energy is distributed among hadrons following final state interactions is likely to be crucial to achieving improved agreement. Overall, this work provides a novel characterisation of neutrino interactions whilst offering guidance for refining existing generator predictions.

    ↳ hep-exhep-phPRD(2025)·25 citations
43. 43*

    Negative neutrino masses as a mirage of dark energy

    Willem Elbers🇬🇧 · Carlos S. Frenk🇬🇧 · Adrian Jenkins🇬🇧 · Baojiu Li🇬🇧 · Silvia Pascoli🇮🇹

    The latest cosmological constraints on the sum of the neutrino masses depend on prior physical assumptions about the mass spectrum. To test the accordance of cosmological and laboratory constraints in the absence of such priors, we introduce an effective neutrino mass parameter that extends consistently to negative values. For the $\Lambda$CDM model, we analyze data from Planck, ACT, and DESI and find a $2.8-3.3\sigma$ tension with the constraints from oscillation experiments. Motivated by recent hints of evolving dark energy, we analyze the $w_0{w}_a$ and mirage dark energy models, showing that they favour larger masses consistent with laboratory data, respectively $\sum m_{\nu ,\mathrm{eff}}=0.06_{-0.10}^{+0.15}\mathrm{eV}$ and $\sum m_{\nu ,\mathrm{eff}}=0.04_{-0.11}^{+0.15}\mathrm{eV}$ (both at 68%).

    ↳ astro-ph.COhep-phPRD(2025)·92 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.