Thu·Nov 7, 2024Thursday·November 7, 2024

1. 01*

   Dark Matter in the High-Scale Seesaw Leptogenesis Paradigm

   Juan Herrero-Garcia🇪🇸 · Giacomo Landini🇪🇸 · Tsutomu T. Yanagida🇯🇵

   The seesaw mechanism with three heavy Majorana right-handed neutrinos provides an elegant explanation for neutrino masses and, combined with leptogenesis, can generate the baryon asymmetry of the universe (BAU). Naturally embedded in a Grand Unified Theory, this framework stands as one of the best-motivated extensions beyond the Standard Model, but it is very difficult to test it. Moreover, it does not account for dark matter (DM). In this paper, we propose a minimal extension that introduces a dark sector with a singlet Majorana fermion (as the DM candidate) and a complex scalar singlet. The heavy right-handed neutrinos serve another role beyond generating neutrino masses and the BAU: producing the cold DM density through their decays. Interestingly, the model also predicts a subdominant DM component from late scalar decays, which in some cases may be hot or warm at the onset of structure formation, as well as an equal number of non-thermal neutrinos. These components leave distinct signatures in various cosmological observables. Furthermore, electromagnetic energy injection from scalar decays alter predictions from Big Bang Nucleosynthesis and induce spectral distortions in the Cosmic Microwave Background black-body spectrum. In this context, upcoming experiments, such as the Primordial Inflation Explorer (PIXIE), could probe the mechanism of neutrino mass generation.

   hep-phPRD(2025)·4 citations
2. 02*

   Boxed in from all sides: a global fit to loopy dark matter and neutrino masses

   Karen Macías Cárdenas🇪🇸 · Gopolang Mohlabeng🇺🇸 · Aaron C. Vincent🇨🇦

   We investigate a dark matter model that couples to the standard model through a one-loop interaction with neutrinos, where the mediator particles also generate neutrino masses. We perform a global fit that incorporates dark matter relic abundance, primordial nucleosynthesis, neutrino mass, collider and indirect detection constraints. Thanks to the loop suppression, large couplings are allowed, and we find that the model parameters are constrained on all sides. Dark matter masses from 10 MeV to a few TeV are allowed, but sub-GeV masses are preferred for the model to also account for the heaviest neutrino mass. Though our results are valid for a single neutrino mass eigenstate at a time, the model and methods are generalizable to the full 3-flavor case.

   hep-phastro-ph.COPRD(2025)·6 citations
3. 03*

   Remarkable Scale Relation, Approximate SU(5), Fluctuating Lattice

   Holger Bech Nielsen🇩🇰

   We discuss a series of 8 energy scales, some of which just speculated by ourselves, and fit the logarithms of these energies as a straight line versus a quantity related to the dimensionalities of action terms in a way to be defined in the article. These terms in the action are related to the energy scales in question. So e.g. the dimensionality of Einstein Hilbert action coefficient is one related to the Planck scale. In fact we suppose in the cases described with quantum field theory, that there is for each of our energy scales a pair of associated terms in the Lagrangian density, one "kinetic" and one "mass- or current" term. We use for our plotting of the energy scales the ratio of the dimensionality of say the "non-kinetic" to the dimensionality of the "kinetic" one The explanation for our phenomenological finding that the logarithm of the energies depend as a straight line on the dimensionality defined integer $q$, we give as an ontological - i.e. it really exists in nature in our model -"fluctuating lattice" with a very broad distribution of say the link size $a$.We take it Gaussian in the logarithm, $\ln (a)$. A fluctuating lattice is very natural in a theory with general relativity, since it corresponds to fluctuations in the gauge d.o.f. of general relativity. Intriguing are the lowest ones of our energy scales, being by us not described by quantum field theory as the other ones, but by actions for single particle or single string respectivily, because the string scale fits well with hadronic strings, and the particle scale is presumably the mass scale of Standard Model group monopoles, a bound state of a couple of which might be the dimuon resonance (or statistical fluctuation) found in LHC with mass 28 GeV.

   hep-phUniverse(2025)·4 citations
4. 04*

   Tri-meson state $\bar{\mathbf{B}}{\bar{\mathbf{B}}}^{\ast }{\bar{\mathbf{B}}}^{\ast }$

   Cheng-Rong Deng🇨🇳 · Chun-Sheng An🇨🇳

   We systematically explore the trimeson states $\bar{B}{\bar{B}}^{\ast }{\bar{B}}^{\ast }$ with various isospin-spin configurations in the quark model by solving exactly the six-body Schrödinger equations with the Gaussian expansion method. The configuration ${\left[[\bar{B}{\bar{B}}^{\ast }{]}_0^1{\bar{B}}^{\ast }\right]}_{\frac{1}{2}}^0$ is not only approximately 10.2 MeV lower than the threshold of its constituent particles but also about 0.2 MeV below that of the compact tetraquark state $[\bar{B}{\bar{B}}^{\ast }{]}_0^1$ and ${\bar{B}}^{\ast }$. This configuration manifests a loose two-body bound state composed of $[\bar{B}{\bar{B}}^{\ast }{]}_0^1$ and ${\bar{B}}^{\ast }$, with a size of around 4.75 fm. In contrast, the configurations ${\left[[\bar{B}{\bar{B}}^{\ast }{]}_1^1{\bar{B}}^{\ast }\right]}_{\frac{1}{2}}^0$, ${\left[\bar{B}[{\bar{B}}^{\ast }{\bar{B}}^{\ast }{]}_1^0\right]}_{\frac{1}{2}}^0$, and ${\left[[\bar{B}{\bar{B}}^{\ast }{]}_1^1{\bar{B}}^{\ast }\right]}_{\frac{1}{2}}^1$ exhibit binding energies of less than 1 MeV relative to their constituent particles, establishing a loose three-meson bound state. After coupling three configurations with $\frac{1}{2}{0}^{-}$, the trimeson state with $\frac{1}{2}{0}^{-}$ remains a loosely two-body bound state with a binding energy around 1.5 MeV and a huge size of 2.20 fm, in which the configuration ${\left[[\bar{B}{\bar{B}}^{\ast }{]}_0^1{\bar{B}}^{\ast }\right]}_{\frac{1}{2}}^0$ is dominant, contributing $80\%$ to the overall probability. Among the four bound configurations, the $\sigma$-meson exchange plays a decisive role. The meson pair $[\bar{B}{\bar{B}}^{\ast }{]}_0^1$, resembling the short-range strong correlated $p$-$n$ pair in nuclear physics, prevails over other types of meson pairs. The meson pair $[\bar{B}{\bar{B}}^{\ast }{]}_0^1$ not only contributes to the binding mechanisms but also influences the spatial structures of those stable trimeson configurations.

   hep-phPRD(2025)·2 citations
5. 05*

   Next-to-Next-to-Leading-Order QCD Prediction for the Pion Form Factor

   Yao Ji🇩🇪 · Bo-Xuan Shi🇨🇳 · Jian Wang🇨🇳 · Ye-Fan Wang🇨🇳 · Yu-Ming Wang🇨🇳 · Hui-Xin Yu🇨🇳

   We accomplish for the first time the two-loop computation of the leading-twist contribution to the pion electromagnetic form factor by employing the effective field theory formalism rigorously. The next-to-next-to-leading-order short-distance matching coefficient is determined by evaluating the appropriate $5$-point QCD amplitude with the modern multi-loop technique and subsequently by implementing the ultraviolet renormalization and infrared subtractions with the inclusion of evanescent operators. The renormalization/factorization scale independence of the obtained form factor is then validated explicitly at $\mathcal{O}({\alpha }_s^3)$. The yielding two-loop QCD correction to this fundamental quantity turns out to be numerically significant at experimentally accessible momentum transfers. We further demonstrate that the newly computed two-loop radiative correction is highly beneficial for an improved determination of the leading-twist pion distribution amplitude.

   hep-phhep-exhep-latPRL(2025)·14 citations
6. 06*

   TMD-like functions through the twisted quark states

   I.V. Anikin🇷🇺 · Xurong Chen🇨🇳

   We investigate a new class of transverse momentum dependent functions (TMDs), as known as align-spin (AS) functions. In the paper, we propose the most suitable proof of the AS-function existence together with the demonstration of the preponderances if the framework of twisted quark states has been employed. The twisted state corresponds to the elementary particle (quark) which possesses the nontrivial intrinsic orbital angular momentum owing to the swirling trajectory of motion. In its turn, it leads to the cylindric system applied for the consideration. In this connection, we reveal that the twisted (vortex) quark states serve as effective tools for the study of TMDs, thereby facilitating a comprehensive analysis of AS-functions. In contrast to the previous studies, where the existence of new TMDs is related to the the corresponding interactions encoded in the correlators, we now focus on the leading order of interactions providing a simplified and robust method. This has been ensured by the twisted quark in the corresponding correlator because the essential transverse momentum dependence of quarks generated by interactions in the correlators can be alternatively described by the twisted states. Using a cylindrical formulation for twisted states, we can combine the properties of plane-wave particles with a description stemmed from spherical harmonics, resulting in well-defined propagation directions accompanied by essential OAM projections. In particular, this innovative framework opens a new window for the direct investigations of AS-functions, generating the unique angular $\varphi$-dependence of differential cross sections. It also points towards promising applications in experimental particle physics.

   hep-phhep-thPTEP(2025)·0 citations
7. 07*

   Speed of sound and trace anomaly in a unified treatment of the two-color diquark superfluid, the pion-condensed high-isospin matter, and the 2SC quark matter

   Kenji Fukushima🇯🇵 · Shuhei Minato🇯🇵

   In a unified perturbative treatment from the high-density side, we compute the speed of sound and the trace anomaly as functions of the chemical potential $\mu$ for the two-color diquark superfluid, the pion-condensed high-isospin matter, and the 2SC quark matter. We find that the corrections induced by the gap energy $\Delta$ involve nontrivial interplay between the dimensionless magnitude $|\Delta /\mu |$ and the derivative $|\partial \Delta /\partial \mu |$. Even though the gap equation has a common structure for these phases of our interest, different numerical constants cause drastic changes in the speed of sound corrections. As long as $|\Delta /\mu |$ is dominant over the derivative, the gap effects increase the speed of sound, which is consistent with the expected behavior of exhibiting a peak at intermediate density. We then discuss the trace anomaly which is pushed down generally by the gap effects and turns out to be negative widely in the high density regime. For demonstration of non-perturbative enhancement, we take account of the instanton-induced interaction. We confirm a further increase in the speed of sound for the two-color diquark superfluid and the pion-condensed high-isospin matter, while the speed of sound for the 2SC quark matter deviates far below the conformal limit due to the derivative contribution.

   hep-phnucl-thPRD(2025)·35 citations
8. 08*

   The new states $X(1910)$ and $X(2300)$ and higher light excited $J^{PC}=1^{+-}$ mesons

   Ya-Rong Wang🇨🇳 · Xiao-Hai Liu🇨🇳 · Cheng-Qun Pang🇨🇳 · Hao Chen🇨🇳

   The BESIII Collaboration recently reported the observation of two new resonances, $X(1910)$ and $X(2300)$, which have sparked our interest in studying the light hadron family with $J^{PC}=1^{+-}$ . In this work, we investigate the mass spectra and OZI-allowed two-body strong decays of $b_1$, $h_1$, and $h_1^{\prime }$ using the MGI model and QPC model with newly fitted parameters. We also explore the possibility of identifying $X(1910)$ and $X(2300)$ as $h_1$ or $h_1^{\prime }$ states. Our numerical results suggest that $X(1910)$ could be a promising candidate for the $h_1^{\prime }(2^1{P}_1)$ state with quark content $s\bar{s}$, while the structure of $X(2300)$ remains uncertain.

   hep-phPRD(2025)·9 citations
9. 09*

   Dijet mass up to four-loops with(out) ${\mathbf{k}}_{\mathbf{t}}$ clustering

   K. Khelifa-Kerfa🇩🇿

   We compute the invariant mass of dijets produced in $e^{+}{e}^{-}$ annihilation processes up to four loops in perturbation theory for both anti-$k_t$ and $k_t$ jet algorithms. The calculations, performed within the eikonal approximation and employing strong-energy ordering, capture the full analytic structure of the leading Abelian and non-Abelian non-global logarithms, including full colour and jet-radius dependence. We evaluate the significance of these logarithms and the convergence of the four loop perturbative expansion by comparing with all-orders numerical results.

   hep-phhep-thEPJC(2025)·5 citations
10. 10*

    $B\to K\bar{K}(\pi \eta )h$ decays in the presence of isovector scalar resonances $a_0(980,1450)$

    Si-Yang Wang🇨🇳 · Zhi-Qing Zhang🇨🇳 · Zhi-Jie Sun🇮🇷 · Jian Chai🇨🇳 · Peng Li🇨🇳

    Different from the previous treatment in a two-body framework, we introduce the dimeson distribution amplitudes (DAs) to describe the strong dynamics between the S-wave resonances $a_0(980,1450)$ and the $K\bar{K}(\pi \eta )$ pair, where the Gegenbauer coefficient required is determined from the experimental data on the time-like form factors involved. The branching ratios and direct CP asymmetries of the decays $B\to a_0^{(\prime )}h\to K\bar{K}(\pi \eta )h$, with $a_0=a_0(980)$, $a_0^{\prime }=a_0(1450)$ and $h$ referring to a pion or a kaon, are then calculated in the perturbative QCD (PQCD) approach. We find that the branching ratios of the corresponding quasi-two-body decays $B\to a_0^{(\prime )}K$ obtained with the narrow width approximation are closer to those predicted in the QCD factorization (QCDF) approach compared to the previous PQCD calculations, no matter a three-body or a two-body framework is assumed. Furthermore, all our predictions for these $B\to a_0^{(\prime )}K$ decays are below the current experimental upper limits except for those of decays $B^0\to a_0^{(\prime )-}{K}^{+}$, which are (slightly) larger than the upper limits. Under the narrow width approximation, the branching ratios of the decays $B^{+}\to a_0^{(\prime )+}{\pi }^0$, $B^0\to a_0^{(\prime )+}{\pi }^{-}$ and $B^0\to a_0^{(\prime )0}{\pi }^0$ are comparable to or agree well with the previous PQCD and the QCDF calculations. While for the decays $B^{+}\to a_0^{(\prime )0}{\pi }^{+}$ and $B^0\to a_0^{(\prime )-}{\pi }^{+}$, their branching ratios are predicted to be unexpectedly large, for example, the obtained branching ratio of decay $B^{+}\to a_0^0{\pi }^{+}$ is even higher than the current experimental upper limit.

    hep-phhep-exPRD(2025)·0 citations
11. 11*

    Astrophysical constraints on color-superconducting phases in compact stars within the RG-consistent NJL model

    Hosein Gholami🇩🇪 · Ishfaq Ahmad Rather🇩🇪 · Marco Hofmann🇩🇪 · Michael Buballa🇩🇪 · Jürgen Schaffner-Bielich🇩🇪

    We determine parameters of the renormalization group-consistent three-flavor color-superconducting Nambu-Jona-Lasinio (NJL) model that are suited to investigate possible compact-star configurations. Our goal is to provide quark-matter equations of state (EoS) that can be used for hadron-quark hybrid-star constructions. To that end, we mainly focus on the parameters of the quark-matter model. By varying the vector and diquark coupling constants, we analyze their impact on the EoS, the speed of sound, the maximum diquark gap, and the mass-radius relation. In almost all configurations, a stable color-flavor-locked (CFL) phase appears in the core of the maximum-mass configurations, typically spanning several kilometers in radius. In other cases, the star's two-flavor color-superconducting (2SC) branch of the EoS becomes unstable before reaching the CFL transition density. At neutron-star densities, the speed of sound squared reaches up to $c_s^2\sim 0.6$ and the CFL gap up to $\Delta \sim 250$MeV. We argue that adding a hadronic EoS at lower densities by performing a Maxwell construction does not increase the maximum mass substantially. Thus we use the $2.0M_{\odot }$ constraint to constrain the NJL model parameters that are suited for the construction of hybrid-star EoS. We construct three examples of the hybrid-star model, demonstrating that there is room for different color-superconducting compositions. The hybrid EoSs obtained in this way can have no 2SC matter or different ratios of 2SC and CFL quark matter in the core. We show that early hadron-quark transitions are possible that can modify the tidal deformability at 1.4 $M_{\odot }$. We find that these EoSs are consistent with the imposed constraints from astrophysics and perturbative QCD. They allow for different hybrid-star scenarios with a hadronic EoS that is soft at low to intermediate densities ($\sim 1-3n_{\text{sat}}$).

    hep-phastro-ph.SRnucl-thPRD(2025)·55 citations
12. 12*

    Double Parton Scattering Effects on the Measurement of the W-Boson Mass

    Rui Zhang🇨🇳 · Zhen Zhang🇨🇳

    Double parton scattering (DPS) corresponds to events where two parton-parton scatterings occur in a single hadron-hadron collision. The DPS effects may arise from the spectator scatterings that are somewhat related to semi-hard QCD activities. In this work, we investigate the DPS effects on the W-boson mass measurements. Especially, our analysis reveals that the DPS effects contribute additional missing transverse momenta from spectator scatterings as well as relevant inclusive cross sections, potentially altering the distribution of total missing transverse momenta. Consequently, the DPS effects have the potential to cause an increase in the measured W-boson mass by the CDF detector, which helps to understand the deviation of the CDF-II measurements from other measurements and the predicted value in the Standard Model. This could be further validated in upcoming studies, such as the W-like analyses of the Z boson production, which will potentially open new avenues for probing QCD dynamics in the semi-hard regime.

    hep-phhep-exJHEP(2026)·1 citation
13. 13*

    Twist-3 contribution to deeply virtual electroproduction of pions

    Kornelija Passek-K.🇭🇷

    We discuss deeply virtual meson production (DVMP), focusing on the role of higher-twist contributions in the description of deeply virtual pseudoscalar mesons at experimentally accessible energies. The standard collinear approach at the lowest twist does not adequately describe deeply virtual ${\pi }_0$ production. By incorporating twist-2 transversity generalized parton distributions (GPDs) and a twist-3 meson distribution amplitude, we have determined the twist-3 contribution, which includes both the 2-body ($q\bar{q}$) and 3-body ($q\bar{q}g$) meson Fock components. Two methods to regularize the end-point singularities are introduced - quark transverse momenta and a gluon mass. The resulting cross sections show good agreement with experimental data, paving the way for a more comprehensive confrontation of theory and experiment at leading order and beyond.

    hep-phhep-exPoS(2024)·0 citations
14. 14*

    TeV-scale particles and LHC events with dijet pairs

    Bogdan A. Dobrescu🇺🇸

    Scalar particles that couple to two up quarks may be produced at the LHC even if they are ultraheavy, in the $8-10$ TeV mass range. A renormalizable theory that includes a diquark particle of this type ($S_{uu}$), two vectorlike quarks (${\chi }_1,{\chi }_2$), and a gauge-singlet pseudoscalar, predicts LHC signals involving four or more jets of very high $p_T$. Two remarkable events observed by the CMS experiment, each involving four high $p_T$-jets, may be due to an $S_{uu}$ of mass near 8.5 TeV, and a ${\chi }_2$ mass of 2.1 TeV. A separate excess reported by CMS in the nonresonant dijet pair search is consistent with a ${\chi }_1$ mass of $0.95$ TeV. This hypothesis may be tested through CMS and ATLAS searches for signals with a pair of dijet resonances of masses clustered around 1 TeV, and separately around 2 TeV, which have $4j$ invariant masses in the $5-8$ TeV range. These additional signals would arise from cascade decays of $S_{uu}\to {\chi }_2{\chi }_2$, which lead to $5j$ and $6j$ events with invariant masses around 8 TeV. Depending on the couplings of the heavy colored particles, additional signals are possible, involving for example highly-boosted top quarks.

    hep-phJHEP(2025)·11 citations
15. 15*

    Parametrization of GPDs from t-channel string exchange in AdS spaces

    Kiminad A. Mamo🇺🇸 · Ismail Zahed🇺🇸

    We introduce a string-based parametrization for nucleon quark and gluon generalized parton distributions (GPDs) that is valid for all skewness. Our approach leverages conformal moments, representing them as the sum of spin-j nucleon A-form factor and skewness-dependent spin-j nucleon D-form factor, derived from t-channel string exchange in AdS spaces consistent with Lorentz invariance and unitarity. This model-independent framework, satisfying the polynomiality condition due to Lorentz invariance, uses Mellin moments from empirical data to estimate these form factors. With just five Regge slope parameters, our method accurately produces various nucleon quark GPD types and symmetric nucleon gluon GPDs through pertinent Mellin-Barnes integrals. Our isovector nucleon quark GPD is in agreement with existing lattice data, promising to improve the empirical extraction and global analysis of nucleon GPDs in exclusive processes, by avoiding the deconvolution problem at any skewness, for the first time.

    hep-phhep-lathep-thnucl-thPRL(2024)·20 citations
16. 16*

    Probing QCD Axions or Axion-like Particles in three-body $K$ Decays

    Mael Cavan-Piton🇫🇷 · Diego Guadagnoli🇫🇷 · Axel Iohner🇫🇷 · Diego Martinez Santos🇪🇸 · Ludovico Vittorio🇫🇷

    Two-body decays like $K\to \pi a$ rank among the most constraining collider probes for new, low-mass, feebly interacting pseudoscalar particles $a$. We explore an alternative class of kaon decay modes, specifically three-body decays to $\pi \pi a$ or $\mu \mu a$. The former occur at tree level, while the latter is loop-suppressed yet accidentally finite. These modes specifically leverage the accurate tracking capabilities at LHCb. We present an estimation approach for the sensitivity achievable in future searches within these channels. Our argument uses the current uncertainty in leading irreducible backgrounds identified for each channel. Our findings suggest that dedicated searches could probe $f_a$ scales between $10^4$ and $10^6$ TeV, highlighting their strong potential. A direct comparison with actual searches, only available in the $K^{+}\to {\pi }^{+}{\pi }^{0}a$ channel, supports this conclusion. Finally, we show that, in these searches, reconstruction efficiency maps are such that large efficiencies are naturally aligned with regions of higher yields in Dalitz plots.

    hep-phhep-exJHEP(2025)·7 citations
17. 17*

    The Geometric Universal One-Loop Effective Action

    Xu-Xiang Li🇺🇸 · Xiaochuan Lu🇺🇸 · Zhengkang Zhang🇺🇸

    We derive universal formulae for integrating out heavy degrees of freedom in scalar field theories up to one-loop level in terms of covariant quantities associated with the geometry of the field manifold. The universal matching results can be readily applied to phenomenologically interesting extensions of the Standard Model, as we demonstrate using a singlet scalar example. We also discuss the role of field redefinitions in effective field theory matching and simplifications resulting from going to a field basis where interactions are encoded in a nontrivial metric on the field manifold.

    hep-phhep-thJHEP(2025)·14 citations
18. 18*

    Cosmic (super)strings with a time-varying tension

    Filippo Revello🇧🇪 · Gonzalo Villa🇬🇧

    Cosmic (super)strings offer promising ways to test ideas about the early universe and physics at high energies. While in field theory constructions their tension is usually assumed to be constant (or at most slowly-varying), this is often not the case in the context of String Theory. Indeed, the tensions of both fundamental and field theory strings within a string compactification depend on the expectation values of the moduli, which in turn can vary with time. We discuss how the evolution of a cosmic string network changes with a time-dependent tension, both for long-strings and closed loops, by providing an appropriate generalisation of the Velocity One Scale (VOS) model and its implications. The resulting phenomenology is very rich, exhibiting novel features such as growing loops, percolation and a radiation-like behaviour of the long string network. We conclude with a few remarks on the impact for gravitational wave emission.

    hep-phastro-ph.COhep-thJCAP(2025)·22 citations
19. 19*

    Gravitational Wave Production During Reheating: From the Inflaton to Primordial Black Holes

    Mathieu Gross🇫🇷 · Essodjolo Kpatcha🇪🇸 · Yann Mambrini🇫🇷 · Maria Olalla Olea-Romacho🇬🇧 · Rishav Roshan🇬🇧

    We calculate the gravitational waves (GWs) produced by primordial black holes (PBHs) in the presence of the inflaton condensate in the early Universe. Combining the GW production from the evaporation process, the gravitational scattering of the inflaton itself, and the density fluctuations due to the inhomogeneous distribution of PBHs, we propose for the first time a complete coherent analysis of the spectrum, revealing three peaks, one for each source. Three frequency ranges ($\sim$ kHz, GHz, and PHz, respectively) are expected, each giving rise to a similar GW peak amplitude ${\Omega }_{\mathrm{GW}}$. We also compare our predictions with current and future GWs detection experiments.

    hep-phastro-ph.COPRD(2025)·23 citations
20. 20*

    Constraining low scale dark hypercharge symmetry at spallation, reactor and Dark Matter direct detection experiments

    Anirban Majumdar🇮🇳 · Dimitrios K. Papoulias🇪🇸 · Hemant Prajapati🇮🇳 · Rahul Srivastava🇮🇳

    Coherent elastic neutrino-nucleus (CE$\nu$NS) and elastic neutrino-electron scattering (E$\nu$ES) data are exploited to constrain ``chiral'' $U(1{)}_X$ gauged models with light vector mediator mass. These models fall under a distinct class of new symmetries called dark hypercharge symmetries. A key feature is the fact that the $Z^{\prime }$ boson can couple to all Standard Model fermions at tree level, with the $U(1{)}_X$ charges determined by the requirement of anomaly cancellation. Notably, the charges of leptons and quarks can differ significantly depending on the specific anomaly cancellation solution. As a result, different models exhibit distinct phenomenological signatures and can be constrained through various experiments. In this work, we analyze the recent data from the COHERENT experiment, along with results from dark matter (DM) direct detection experiments such as XENONnT, LUX-ZEPLIN, and PandaX-4T, and place new constraints on three benchmark models. Additionally, we set constraints from a performed analysis of TEXONO data and discuss the prospects of improvement in view of the next-generation DM direct detection DARWIN experiment.

    hep-phhep-exPRD(2025)·17 citations
21. 21*

    Investigating the Origin of CMB Large-Scale Features Using LiteBIRD and CMB-S4

    Catherine Petretti🇺🇸 · Matteo Braglia🇺🇸 · Xingang Chen🇺🇸 · Dhiraj Kumar Hazra🇮🇳 · Sonia Paban🇺🇸

    Several missions following Planck are currently under development, which will provide high-precision measurements of the Cosmic Microwave Background (CMB) anisotropies. Specifically, measurements of the E modes will become nearly limited by cosmic variance, which, especially when considering the sharpness of the E-mode transfer functions, may allow for the ability to detect deviations from the concordance model in the CMB data. We investigate the capability of upcoming missions to scrutinize models that have been proposed to address large-scale anomalies observed in the temperature spectra from WMAP and Planck. To this purpose, we consider four benchmarks that modify the CMB angular power spectra at large scales: models producing suppression, a dip, and amplification in the primordial scalar power spectrum, as well as a beyond-Lambda CDM prescription of dark energy. Our analysis shows that large-scale measurements from LiteBIRD will be able to distinguish between various types of primordial and late-time models that predict modifications to the angular spectra at these scales. Moreover, if these deviations from the standard cosmological model are determined to be systematic and do not reflect the true universe model, future experiments could potentially dismiss these features as statistical fluctuations. We also show that additional measurements from CMB-S4 can impose more stringent constraints by probing correlated signals that these models predict at smaller scales (l>100). A byproduct of our analysis is that a recently proposed "Dark Dimension" scenario, featuring power amplification at large scales, is strongly bound by current data, pushing the deviation from the standard model to unobservable scales. Overall, our results demonstrate that future CMB measurements can provide valuable insights into large-scale anomalies that are present in the current CMB data.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2025)·15 citations
22. 22*

    A pathway to unveiling neutrinoless $\beta \beta$ decay nuclear matrix elements via $\gamma \gamma$ decay

    Beatriz Romeo🇪🇸 · Damiano Stramaccioni🇮🇹 · Javier Menéndez🇪🇸 · Jose Javier Valiente-Dobón🇮🇹

    We investigate the experimental feasibility of detecting second-order double-magnetic dipole ($\gamma \gamma$-$M1M1$) decays from double isobaric analog states (DIAS), which have recently been found to be strongly correlated with the nuclear matrix elements of neutrinoless $\beta \beta$ decay. Using the nuclear shell model, we compute theoretical branching ratios for $\gamma \gamma$-$M1M1$ decays and compare them with other competing processes, such as single-$\gamma$ decay and proton emission, which represent the dominant decay channels. We also estimate the potential competition from internal conversion and internal pair creation, which can influence the decay dynamics. Additionally, we propose an experimental strategy based on using LaBr${}_3$ scintillators to identify $\gamma \gamma$-$M1M1$ transitions from the DIAS amidst the background of the competing processes. Our approach emphasizes the challenges of isolating the rare $\gamma \gamma$-$M1M1$ decay and suggests ways to enhance the experimental detection sensitivity. Our simulations suggest that it may be possible to access experimentally $\gamma \gamma$-$M1M1$ decays from DIAS, shedding light on the neutrinoless $\beta \beta$ decay nuclear matrix elements.

    ↳ nucl-thhep-exhep-phnucl-exPLB(2025)·4 citations
23. 23*

    Phase transition on superfluid vortices in Higgs-Confinement crossover

    Tomoya Hayata🇯🇵 · Yoshimasa Hidaka🇯🇵 · Dan Kondo🇯🇵

    We propose a novel method to distinguish states of matter by identifying spontaneous symmetry breaking on extended objects, such as vortices, even in the absence of a bulk phase transition. As a specific example, we investigate the phase transition on superfluid vortices in the Higgs-confinement crossover using a $\mathrm{U}(1{)}_{\mathrm{gauge}}\times \mathrm{U}(1{)}_{\mathrm{global}}$ model. This model exhibits superfluidity of $\mathrm{U}(1{)}_{\mathrm{global}}$ symmetry and allows for a crossover between the Higgs and confinement regimes by varying the gauge coupling constant from weak to strong. We demonstrate that, on vortices, spontaneous breaking of the ${\mathbb{Z}}_2$ flavor symmetry occurs in the weak coupling (Higgs) regime, while it does not in the strong coupling (confinement) regime. We also confirm that those regimes are separated by a second-order phase transition through Monte Carlo simulations, whose universality class corresponds to the two-dimensional Ising model.

    ↳ hep-thcond-mat.supr-conhep-lathep-ph+1JHEP(2025)·3 citations
24. 24*

    RHIC $\sqrt{s_{NN}}=200$ GeV hadron yields and the isospin dependent equation of state

    Feyisola Nana · Jordi Salinas San Martín🇺🇸 · Jacquelyn Noronha-Hostler🇺🇸

    The statistical hadronization model has been successful in extracting information at chemical freeze-out in heavy-ion collisions. At RHIC, with a collision energy of $\sqrt{s_{NN}}=200$ GeV, many different ion species have been used for $A$+$A$ collisions. This allows for a scan across the charge fraction $Y_Q=Z/A$, where $Z$ is the proton number and $A$ is the baryon number. We first make predictions for $A$+$A$ collisions that do not yet have published experimental data on hadron yield ratios (O+O, Ru+Ru, Zr+Zr). We then use both the experimental and predicted yield ratios to perform thermal fits across $Y_Q$, enabling us to extract $s/n_B$ and other thermodynamic information at chemical freeze-out. Using the relation between $s/n_B$ and $Y_Q$, we can calculate a new constraint on the finite temperature equation of state at finite densities. We discuss implications of this constraint and propose future runs that can help connect to the equation of state relevant for neutron star mergers.

    ↳ nucl-thhep-ph3 citations
25. 25*

    Science and Project Planning for the Forward Physics Facility in Preparation for the 2024-2026 European Particle Physics Strategy Update

    Jyotismita Adhikary🇵🇱 · Luis A. Anchordoqui🇺🇸 · Akitaka Ariga🇨🇭 · Tomoko Ariga🇯🇵 · Alan J. Barr🇬🇧 · Brian Batell🇺🇸 · Jianming Bian🇺🇸 · Jamie Boyd🇨🇭 · Matthew Citron🇺🇸 · Albert De Roeck🇨🇭 · Milind V. Diwan🇺🇸 · Jonathan L. Feng🇺🇸 and 14 other authors

    The recent direct detection of neutrinos at the LHC has opened a new window on high-energy particle physics and highlighted the potential of forward physics for groundbreaking discoveries. In the last year, the physics case for forward physics has continued to grow, and there has been extensive work on defining the Forward Physics Facility and its experiments to realize this physics potential in a timely and cost-effective manner. Following a 2-page Executive Summary, we present the status of the FPF, beginning with the FPF's unique potential to shed light on dark matter, new particles, neutrino physics, QCD, and astroparticle physics. We summarize the current designs for the Facility and its experiments, FASER2, FASER$\nu$2, FORMOSA, and FLArE, and conclude by discussing international partnerships and organization, and the FPF's schedule, budget, and technical coordination.

    ↳ hep-exhep-phphysics.ins-detEPJC(2025)·41 citations
26. 26*

    Search for Axions from Magnetic White Dwarfs with Chandra

    Orion Ning🇺🇸 · Christopher Dessert🇺🇸 · Vi Hong🇺🇸 · Benjamin R. Safdi🇺🇸

    Low mass axion-like particles could be produced in abundance within the cores of hot, compact magnetic white dwarf (MWD) stars from electron bremsstrahlung and converted to detectable X-rays in the strong magnetic fields surrounding these systems. In this work, we constrain the existence of such axions from two dedicated Chandra X-ray observations of $\sim$40 ks each in the energy range $\sim$1 - 10 keV towards the magnetic white dwarfs (MWDs) WD 1859+148 and PG 0945+246. We find no evidence for axions, which constrains the axion-electron times axion-photon coupling to $|g_{a\gamma \gamma }{g}_{aee}|\lesssim 1.54\times 10^{-25}$ ($3.54\times 10^{-25}$) GeV${}^{-1}$ for PG 0945+246 (WD 1859+148) at 95% confidence for axion masses $m_a\lesssim 10^{-6}$ eV. We find an excess of low-energy X-rays between 1 - 3 keV for WD 1859+148 but determine that the spectral morphology is too soft to arise from axions; instead, the soft X-rays may arise from non-thermal emission in the MWD magnetosphere.

    ↳ astro-ph.HEastro-ph.SRhep-phPRD(2025)·15 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.