Thu·Oct 30, 2025Thursday·October 30, 2025

1. 01*

   A global analysis of ALP-mediated multiboson production at the LHC

   Fabian Esser🇨🇿 · Alexandre Salas-Bernardez🇪🇸 · Maria Ubiali🇬🇧 · Veronica Sanz🇪🇸

   Axion-like particles (ALPs) provide a well-motivated framework for physics beyond the Standard Model, coupling to gauge bosons through dimension-five operators protected by an approximate shift symmetry. At the LHC, such interactions lead to distinctive signatures in multiboson production, where the ALP appears as an off-shell mediator rather than a narrow resonance. In this work, we present the first global analysis of ALP-mediated multiboson processes, combining measurements of diphoton, ZZ, $W^{+}{W}^{-}$, dijet, and vector-boson-fusion final states. On the theory side, motivated from a UV perspective, we assume that the ALP couples only to the gauge sector of the SM, and classify the ALP-multiboson vertices that directly govern collider observables. Our results show that the dijet channel dominates the sensitivity to ALP couplings and determines the limits on $c_{\tilde{G}}$, while diboson and VBF processes provide complementary constraints on the electroweak couplings. We further assess the validity of the EFT expansion given the multi-TeV scales probed in the data. This global study provides the most comprehensive picture to date of ALP-gauge interactions from multiboson production at the LHC, and highlights the opportunities for significant improvements with future high-luminosity datasets.

   hep-phPRD(2026)·4 citations
2. 02*

   QCD chiral phase diagram from weak functional renormalization group

   Yuepeng Guan🇨🇳 · Masatoshi Yamada🇯🇵

   We investigate the QCD chiral phase transition at finite temperature and finite baryon density using the functional Renormalization Group (fRG). While conventional fRG studies often employ techniques such as dynamical bosonization to regularize divergences, we instead pursue the weak solution of the fRG equations which allows for non-analytic behavior in the flow to compute the pure fermionic potential $V_k(\psi ,\bar{\psi })$ within the local potential approximation. This approach enables us to explore the effects of purely quark-level fluctuations on dynamical chiral symmetry breaking without introducing any auxiliary bosonic fields. Based on this framework, we present the resulting chiral phase diagram as a function of temperature and baryon chemical potential.

   hep-phhep-thEPJC(2025)·1 citation
3. 03*

   Prospects for a fourth generation of leptons in a 13 TeV p-p collider

   Ramkrishna Joshi🇮🇳 · Riddhiman Roy🇮🇳

   In the Standard Model, three discovered generations of leptons and quarks are known to date. However, speculations about existence of next generations have a strong foothold. In this study, we sequentially extrapolate the Standard Model to include a fourth generation of leptons (l4, nu4) with a massive Dirac neutrino. We perform MC simulated event generation of pp -> l4 l4(bar) scattering processes at an LHC-like p-p collider with sqrt(s) = 13 TeV by considering l4 mass of 190 GeV and nu4 mass of 100 GeV with PYTHIA. We demonstrate mass constraints of sequential leptons from oblique parameters and study important jet and lepton kinematics in our simulation with CMS like constraints. Fourth generation neutrino is stable in this scenario making l4 -> W nu4 the only dominant channel in collider searches. With the cut-flow, we achieve global excess of (1.46 +/- 0.068(stat.)) sigma and local excess of (3.33 +/- 0.241(stat.)) sigma in the 180-300 GeV signal window. Missing Transverse Energy (MET) provides clean signature of nu4. We assess discovery potential of the BSM lepton against lepton mass, center-of-mass energy (Ecom) and luminosities. Higher luminosities and Ecom are promising to probe BSM moderate mass lepton scenarios at present and future colliders.

   hep-ph1 citation
4. 04*

   Impact of shell model interactions on WIMP-nucleus scattering observables for silicon and germanium targets

   Raghda Abdel Khaleq🇦🇺 · Madeleine J. Zurowski🇨🇦

   The nature of dark matter (DM) remains one of the biggest mysteries in physics today. Dark matter direct detection experiments look for nuclear recoil signals from DM-nucleus elastic scattering, which can be used to characterise DM. Nuclear modelling of the target nucleus may impact the predicted DM-nucleus scattering rates, and affect interpretation of experimental signals. In this work, we investigate the impact of nuclear shell model interactions on DM nuclear responses for silicon and germanium targets using a SuperCDMS-like experimental parameters. Nuclear uncertainties resulting from shell model interaction choice in the nuclear form factors are roughly retained at the scattering rate and exclusion limit levels for certain nuclear responses.

   hep-phnucl-thEPJ Web Conf.(2026)·0 citations
5. 05*

   Vorticity-induced effects from Wess-Zumino-Witten terms

   Geraint W. Evans🇹🇼 · Naoki Yamamoto🇯🇵 · Di-Lun Yang🇹🇼

   We study vorticity-induced effects arising from the Wess-Zumino-Witten terms for Nambu-Goldstone modes in chiral perturbation theory. We first provide an alternative derivation of the Wess-Zumino-Witten terms in the presence of external vector, axial-vector, and pseudoscalar fields using a derivative expansion of the fermion determinant. We then employ the previously found correspondence in which vorticity is treated as an axial-vector field coupled to Dirac fermions in flat spacetime. Using this, we derive vorticity-induced contributions for Nambu-Goldstone modes in the presence of electromagnetic fields at finite baryon and isospin chemical potentials, including a vorticity-induced current, a magnetic-field-induced angular momentum, and a vorticity-modified photon-pion coupling. We also briefly discuss the phenomenological implications of these vorticity-induced effects.

   hep-phcond-mat.mes-hallhep-thnucl-thPRD(2026)·5 citations
6. 06*

   NLO event generation for LHC neutrinos and application to flux measurements at FASER

   Peter Krack🇳🇱

   The LHC generates an intense beam of high-energy neutrinos in the forward direction, whose scientific potential has been left unexploited for many years. The FASER and SND@LHC experiments, operating since 2023, have recently measured LHC neutrinos for the first time. In this contribution we discuss how to produce accurate predictions, including NLO QCD corrections and modern parton shower algorithms, for present and future LHC neutrino experiments, including those at the proposed Forward Physics Facility (FPF). To this end, the energy and rapidity distribution of the LHC neutrinos is encoded in a LHAPDF grid interfaced to the neutrino DIS event generator in the POWHEG-BOX-RES framework. This Monte Carlo tool enables the modelling of differential distributions that are sensitive to hadronic final states, initial- and final-state radiation, and realistic acceptance and selection cuts. As a first application, we deploy this event generator to compute fast-interpolation grids and carry out a first determination of the LHC forward neutrino fluxes directly from FASER data using the NNPDF fitting methodology.

   hep-phPoS(2025)·0 citations
7. 07*

   Reinforcement Learning techniques for the flavor problem in particle physics

   A. Giarnetti🇮🇹 · D. Meloni🇮🇹

   This short review discusses recent applications of Reinforcement Learning (RL) techniques to the flavor problem in particle physics. Traditional approaches to fermion masses and mixing often rely on extensions of the Standard Model based on horizontal symmetries, but the vast landscape of possible models makes systematic exploration infeasible. Recent works have shown that RL can efficiently navigate this landscape by constructing models that reproduce observed quark and lepton observables. These approaches demonstrate that RL not only rediscovers models already proposed in the literature but also uncovers new, phenomenologically acceptable solutions.

   hep-phhep-thSymmetry(2026)·5 citations
8. 08*

   Resonant production of millicharged scalars in $k^2>0$ electromagnetic wave background

   Ekaterina Dmitrieva🇷🇺 · Petr Satunin🇷🇺

   We investigate the solution of the Klein-Gordon equation for a charged scalar particle in an electromagnetic plane wave background with $k^2>0$, which can be realized in a medium with a refractive index $n<1$. We reduce the equation of motion to the Mathieu equation, which has resonant solutions that grow exponentially for certain parameter ranges. Physically, this effect leads to anomalous losses for certain beams of electromagnetic fields in a given medium. We set the constraints on the coupling and mass of millicharged particles from the absence of such anomalous losses for optical laser and radio beams.

   hep-ph3 citations
9. 09*

   Mixed Electroweak-QCD Corrections to $H\to \gamma \gamma$

   Wen-Long Sang🇨🇳 · Feng Feng🇨🇳 · Yu Jia🇨🇳

   We present for the first time the complete three-loop mixed electroweak-QCD ($\mathcal{O}(\alpha {\alpha }_s)$) corrections for the decay channel $H\to \gamma \gamma$, by implementing three different on-shell $\alpha$ schemes in computing the electroweak correction. Our studies indicate that the $\mathcal{O}({\alpha }_s)$ correction amounts to approximately $1.7\%$ of the leading-order prediction for the diphoton width, while the $\mathcal{O}(\alpha )$ correction varies from $-4.8\%$ to $1.4\%$ depending on the specific $\alpha$ scheme. The three-loop mixed electroweak-QCD correction may reach $0.6\%$, $0.5\%$, and $0.2\%$ of the LO diphoton width in $\alpha (0)$, $\alpha (M_Z)$, and $G_{\mu }$ schemes, respectively, which is much more significant than the less-than-$0.1\%$ contribution from the three-loop QCD correction. It is also worth noting that the inclusion of the $\mathcal{O}(\alpha {\alpha }_s)$ correction significantly reduces the scheme dependence of the partial width from $0.6$ keV at leading order down to $0.03$ keV. The state-of-the-art Standard Model predictions are $\Gamma [H\to \gamma \gamma ]=9.389÷9.420$ keV, providing a valuable theoretical benchmark for future Higgs factory collider program.

   hep-phhep-ex2 citations
10. 10*

    Advanced parametrisations for hadronic form factors

    Nienke C. Balz🇩🇪 · Florian Herren🇨🇭 · Bastian Kubis🇩🇪 · Simon Mutke🇩🇪 · Méril Reboud🇫🇷

    The rich analytic structure of hadronic form factors makes a theoretically consistent yet easily applicable parametrisation cumbersome. Consequently, most parametrisations are limited to reproducing the simplest analytic features sufficient to describe form factors on their first Riemann sheet. Here, we introduce two novel form factor parametrisations that allow resonance poles and left-hand cuts on the second Riemann sheet to be studied, while also making the connection to partial-wave amplitudes manifest.

    hep-phhep-exhep-latnucl-thJHEP(2026)·4 citations
11. 11*

    Out-of-equilibrium contributions to charm hadrons in a fluid-dynamic approach

    Rossana Facen🇩🇪 · Federica Capellino🇩🇪 · Eduardo Grossi🇮🇹 · Andrea Dubla🇩🇪 · Silvia Masciocchi🇩🇪

    Building on previous studies that demonstrated the applicability of a fluid-dynamic description of charm quarks in the quark-gluon plasma, the present work extends the framework by computing the out-of-equilibrium contributions to the distribution function of charm hadrons. The analysis includes corrections arising from the initial out-of-equilibrium distribution of charm quarks after a free-streaming phase, as well as from the freeze-out surface within fluid dynamics. These results enable the exact computation of integrated yields and transverse momentum distributions of charm hadrons for different values of the spatial diffusion coefficient, thereby providing the basis for a systematic determination of the charm transport coefficients. A preliminary comparison of our model with the available experimental data shows compatibility within uncertainties. In addition, the limits of applicability of the approach are identified by determining the transverse-momentum region in which charm hadrons are described by a well-defined, positive distribution function.

    hep-phnucl-thPRD(2026)·1 citation
12. 12*

    $QQ\bar{Q}\bar{Q}$ Quark System and Gauge/String Duality

    Oleg Andreev🇩🇪

    We propose a stringy description of a system composed of two heavy quarks and two heavy antiquarks, mimicking that in pure $SU(3)$ gauge theory. We present both analytical and numerical studies of the string configurations for rectangular geometries. As an application, we analyze the two lowest Born-Oppenheimer potentials. Our results suggest that, depending on the geometry and quark ordering, the ground state of the $QQ\bar{Q}\bar{Q}$ system may be a hadronic molecule, a tetraquark state, or a superposition of the two. For general geometries, we derive the asymptotic expression for the energy of the tetraquark configuration in the infrared limit and extend this result to multiquark configurations. Here we also demonstrate the universality of the string tension.

    hep-phhep-lathep-thnucl-thPRD(2026)·0 citations
13. 13*

    Muon Beam Dump Experiments probe five-dimensional nature of $U(1{)}_{L_{\mu }-L_{\tau }}$

    Dibyendu Chakraborty🇮🇳 · Arindam Chatterjee🇮🇳 · Ayushi Kaushik🇮🇳 · Kenji Nishiwaki🇮🇳

    We have investigated the prospects of probing the five-dimensional $U(1{)}_{L_{\mu }-L_{\tau }}$ interactions in present and future muon dump experiments, namely, NA64${}_{\mu }$, M${}^3$, MuSIC, and a future muon beam dump experiment. These experiments are classified into two categories: the first two can probe processes where feebly interacting massive particles go into invisible channels, while the latter two can probe processes where these states decay into muon pairs. These two types of experiments are complementary in that they allow exploration of different parameter regions of a model. In our scenario, the presence of multiple massive gauge bosons as Kaluza-Klein (KK) particles leads to an enhancement in the signal events compared to the corresponding four-dimensional scenario. In particular, the decay process into muon pairs enables mass reconstruction of the parent particle, making it possible to directly demonstrate the existence of multiple KK particles in at least some parameter regions. This can provide clear evidence that the origin of the $U(1{)}_{L_{\mu }-L_{\tau }}$ interaction lies in five dimensions. Furthermore, the muon $(g-2)$ value, which is now consistent with the SM, can be used to exclude specific parameter regions for new particles interacting with muons. We also carefully discuss the non-trivial effects arising from nonzero kinetic mixing.

    hep-phhep-exPRD(2026)·2 citations
14. 14*

    Extra dip in ultrahigh energy neutrino spectrum from generalized uncertainty principle

    J. Barranco🇲🇽 · Emiliano Durán🇲🇽

    We revisited the scenario of a resonant enhancement in the oscillation probability due to an interaction potential between neutrinos and dark matter with the novelty of the inclusion of the generalized uncertainty principle. It is shown that a new resonant conversion appears at higher energies. This effect could be tested with future neutrino data as new dips in the ultrahigh energy neutrino flux.

    hep-phastro-ph.HE0 citations
15. 15*

    Minijet thermalization and jet transport coefficients in QCD kinetic theory

    Kirill Boguslavski🇦🇹 · Florian Lindenbauer🇦🇹 · Aleksas Mazeliauskas🇩🇪 · Adam Takacs🇩🇪 · Fabian Zhou🇩🇪

    We apply weakly coupled QCD kinetic theory to investigate the thermalization of high-momentum on-shell partons (minijets) in a Quark-Gluon Plasma (QGP). Our approach incorporates isotropic hard thermal loop screening to model soft quark and gluon exchanges, allowing us to verify consistency with established analytic results of jet transport coefficients. We perform kinetic simulations of minijets propagating through a thermal gluon plasma, incorporating both collinear radiation and elastic scatterings. The resulting evolution is compared to predictions from jet transport coefficients, including the longitudinal and transverse jet-quenching parameters $\hat{q}$, energy loss, and the drag coefficient. We find that standard definitions of jet transport coefficients neglect the contributions from recoiling medium particles. Including these contributions restores consistency with the kinetic evolution. Finally, we show that the minijet thermalization time scales remarkably well with $\hat{q}$ and we produce a phenomenological estimate of the minijet quenching time in heavy-ion collisions.

    hep-phnucl-thJHEP(2026)·6 citations
16. 16*

    Cavendish Tests of Millicharged Particles

    Asher Berlin🇺🇸 · Zachary Bogorad🇺🇸 · Peter W. Graham🇺🇸 · Harikrishnan Ramani🇺🇸

    A terrestrial population of room-temperature millicharged particles can arise if they make up a dark matter subcomponent or if they are light enough to be produced in cosmic ray air showers. In a companion paper, we showed that a simple electrified shell acts as an efficient accumulator for such particles, parametrically enhancing their local density by many orders of magnitude. Here we demonstrate that Cavendish tests of Coulomb's Law, performed since the late 18th century, function as both quasistatic accumulators and detectors for this overdensity. Reinterpretations of these past Cavendish tests thus provide some of the strongest bounds on a terrestrial millicharge population. We also propose surrounding a Cavendish test with an additional charged shell, which significantly improves the sensitivity and can even enable detection of the irreducible density of millicharged particles generated from cosmic rays. Using decades-old technology, this can outperform future accelerator searches for sub-GeV masses.

    hep-phhep-exPRL(2026)·11 citations
17. 17*

    Irreducible Bhabha background in the detection of muonium-antimuonium conversion

    Mitrajyoti Ghosh🇺🇸 · Kevin Liguori🇺🇸 · Takemichi Okui🇺🇸 · Kohsaku Tobioka🇺🇸

    Experiments such as MACS and the proposed MACE study muonium-antimuonium conversion by the energies of the final-state $e^{\pm }$. The $e^{+}$ and $e^{-}$ from an antimuonium decay tend to be non-relativistic and relativistic, respectively, and vice versa for muonium. However, these $e^{\pm }$ can exchange their energies by hard Bhabha scattering, causing muonium to fake an antimuonium decay signal. We compute the rate for this background and find that, while negligible for MACE, it will become larger than the signal for conversion probabilities less than $10^{-18}$. Measuring the helicity of the $e^{-}$ will reduce this to $10^{-22}$.

    hep-phhep-exPRD(2026)·0 citations
18. 18*

    Electric Accumulation of Millicharged Particles

    Asher Berlin🇺🇸 · Zachary Bogorad🇺🇸 · Peter W. Graham🇺🇸 · Harikrishnan Ramani🇺🇸

    A terrestrial population of millicharged particles that interact significantly with normal matter can arise if they make up a dark matter subcomponent or if they are light enough to be produced in cosmic ray air showers. Such particles thermalize to terrestrial temperatures through repeated scatters with normal matter in Earth's environment. We show that a simple electrified shell (e.g., a Van de Graaff generator) functions as an efficient accumulator of such room-temperature millicharged particles, parametrically enhancing their local density by as much as twelve orders of magnitude. This can be used to boost the sensitivity of any detector housed in the shell's interior, such as ion traps and tests of Coulomb's law. In a companion paper, we apply this specifically to Cavendish tests of Coulomb's law, and show that a well-established setup can probe a large region of unexplored parameter space, with sensitivity to the irreducible density of millicharged particles generated from cosmic rays that outperforms future accelerator searches for sub-GeV masses.

    hep-phhep-exPRD(2026)·10 citations
19. 19*

    Determining (All) Dark Matter-Electron Scattering Rates From Material Properties

    Yonit Hochberg🇮🇱 · Majed Khalaf🇮🇱 · Alessandro Lenoci🇮🇱 · Rotem Ovadia🇮🇱

    We show that the scattering rate for any dark matter (DM) interaction with electrons in any target is proportional to several measurable material properties, encapsulated by a single master formula. This generalizes the dielectric function formalism--developed for DM interactions that couple to electron density--to any interaction, incorporating both spin-dependent and spin-independent interactions simultaneously. This formalism links the full many-body response of a target system to the DM probe in a clear and simple form, providing a reliable event rate prediction from measurable material quantities. We demonstrate the utility of our formalism by placing new limits from existing data on a class of spin-dependent light DM interactions, as their rates--contrary to common lore--are determined entirely by the dielectric function. We further highlight a promising avenue for the detection of sub-MeV DM using the rare earth metal Praseodymium, which exhibits a spin-dependent anisotropic response down to the meV scale. Our results lay the groundwork for a rapid systematic investigation of novel electron scattering targets going beyond the classic spin-independent searches, enhancing the prospects for DM detection.

    hep-phhep-ex11 citations
20. 20*

    Deriving a parton shower for jet thermalization in QCD plasmas

    Ismail Soudi🇫🇮 · Adam Takacs🇩🇪

    Jet quenching - the modification of high-energy jets in the quark-gluon plasma - has been extensively studied through weakly coupled scattering amplitudes embedded in parton-shower frameworks. These models, often combined with bulk hydrodynamic evolution, successfully describe a wide range of observables, though they typically rely on assumptions of rapid thermalization and simplified treatments of medium response. Parallel to these developments, jet thermalization has been investigated within the finite-temperature QCD effective kinetic theory, which provides our best microscopic understanding of equilibration in heavy-ion collisions. Early studies of linearized perturbations have highlighted both the promise and the limitations of current approaches, as existing MC implementations face challenges - particularly in the treatment of recoils and particle merging. Building on this foundation, we introduce a new parton-shower algorithm that exactly reproduces the dynamics of the linearized EKT, enabling a first-principles description of jet thermalization with proper inclusion of recoils, holes, quantum statistics, and merging processes.

    hep-phhep-exhep-thnucl-thPRD(2026)·3 citations
21. 21*

    Covariance of Scattering Amplitudes from Counting Carefully

    Mohammad Alminawi🇨🇭

    Invariance of on-shell scattering amplitudes under field redefinitions is a well known property in field theory that corresponds to covariance of on-shell amputated connected functions. In recent years there have been great efforts to define a formalism in which the covariance is manifest at all stages of calculation, mainly resorting to geometrical interpretations. In this work covariance is analysed using combinatorial methods relying only on the properties of the tree level effective action, without referring to specific formulations of the Lagrangian. We provide an explicit proof of covariance of on-shell connected functions and of the existence of covariant Feynman rules and we derive an explicitly covariant closed formula for tree level on-shell connected functions with any number of external legs.

    ↳ hep-thhep-phmath-phmath.MPJHEP(2026)·2 citations
22. 22*

    The cosmological analysis of DES 3$\times$2pt data from the Effective Field Theory of Large-Scale Structure

    Guido D'Amico🇮🇹 · Alexandre Refregier🇨🇭 · Leonardo Senatore🇨🇭 · Pierre Zhang🇨🇭

    We analyze the Dark Energy Survey (DES) Year 3 data using predictions from the Effective Field Theory of Large-Scale Structure (EFTofLSS). Specifically, we fit three two-point observables (3$\times$2pt), galaxy clustering, galaxy-galaxy lensing, and cosmic shear, using the one-loop expressions for the projected angular correlation functions. We validate our pipeline against numerical simulations and we check for several internal consistencies before applying it to the observational data. Fixing the spectral tilt and the baryons abundance, we measure $S_8=0.833\pm 0.032$, ${\Omega }_m=0.272\pm 0.022$, and $h=0.773\pm 0.049$, to about $3.8\%$, $8.1\%$, and $6.3\%$, at $68\%$CL, respectively. Our results are consistent at the $\sim 1.5-2\sigma$ level with those from Planck and the BOSS full-shape analyses, as well as with those from DES collaboration 3$\times$2pt analysis combined with a Big-Bang Nucleosynthesis prior and a Planck prior on $n_s$. The shift in the posterior compared to DES collaboration results highlights the impact of modeling, scale cuts, and choice of prior. The theory code and likelihood used for our analyses, \texttt{PyFowl}, is made publicly available.

    ↳ astro-ph.COhep-phhep-thJCAP(2026)·16 citations
23. 23*

    Isotensor $\pi \pi \pi$ scattering with a $\rho$ resonant subsystem from QCD

    Raúl A. Briceño🇺🇸 · Maxwell T. Hansen🇬🇧 · Andrew W. Jackura🇺🇸 · Robert G. Edwards🇺🇸 · Christopher E. Thomas🇬🇧

    This work presents a lattice quantum chromodynamics (QCD) determination of $\pi \pi \pi$ scattering amplitudes for the isospin-2 channel with angular momentum and parity $J^P=1^{+}$. The calculation is performed using unphysically heavy light-quark masses, corresponding to a pion mass of $m_{\pi }\approx 400$~MeV, for which the $\rho$ meson manifests as a narrow resonance. The analysis employs a previously developed formalism that non-perturbatively relates the finite-volume spectra of two- and three-pion systems to their infinite-volume scattering amplitudes. We combine earlier lattice QCD results for $\pi \pi$ systems with isospins 1 and 2 with new determinations of the isospin-2 three-pion finite-volume spectrum, obtained for three cubic, periodic lattice volumes with box length ranging from $\approx 4/m_{\pi }$ to $6/m_{\pi }$. These combined data constrain the low-lying partial waves of the infinite-volume three-pion K matrix, from which we solve a set of coupled integral equations to extract the corresponding scattering amplitudes.

    ↳ hep-lathep-phhep-thnucl-th12 citations
24. 24*

    Characterization of the Three-Flavor Composition of Cosmic Neutrinos with IceCube

    R. Abbasi🇺🇸 · M. Ackermann🇩🇪 · J. Adams🇳🇿 · S. K. Agarwalla🇺🇸 · J. A. Aguilar🇧🇪 · M. Ahlers🇩🇰 · J.M. Alameddine🇩🇪 · S. Ali🇺🇸 · N. M. Amin🇺🇸 · K. Andeen🇺🇸 · C. Argüelles🇺🇸 · Y. Ashida🇺🇸 and 420 other authors

    Neutrinos oscillate over cosmic distances. Using 11.4 years of IceCube data, the flavor composition of the all-sky neutrino flux from 5\,TeV--10\,PeV is studied. We report the first measurement down to the $\mathcal{O}$(TeV) scale using events classified into three flavor-dependent morphologies. The best fit flavor ratio is $f_e:f_{\mu }:f_{\tau }=0.30:0.37:0.33$, consistent with the standard three-flavor neutrino oscillation model. Each fraction is constrained to be $>0$ at $>$ 90\% confidence level, assuming a broken power law for cosmic neutrinos. We infer the flavor composition of cosmic neutrinos at their sources, and find production via neutron decay lies outside the 99\% confidence interval.

    ↳ astro-ph.HEhep-exhep-phPRL(2026)·15 citations
25. 25*

    Primordial black hole formation from the merger of oscillons

    Kentaro Kasai🇯🇵 · Naoya Kitajima🇯🇵

    We show that the merger of oscillons results in a broad spectrum of the oscillon mass. A huge number of oscillon samples obtained from numerical lattice simulations reveal that the oscillon mass distribution has an exponential tail in a heavy-mass region. This enables us to infer the fractional abundance of heavy oscillons. Using the criterion for the primordial black hole (PBH) formation from the oscillon collapse obtained in previous studies, we estimate the abundance of PBHs and conclude that a sizable number of PBHs can be produced from oscillons. It can be an alternative PBH formation mechanism without employing the tuning of the inflaton potential to enhance the small-scale density fluctuations in the conventional PBH formation scenario.

    ↳ astro-ph.COhep-phPRD(2026)·6 citations
26. 26*

    Morphology of Inflationary Gravitational Wave Spectra imprinted by a Sequence of Post-Inflationary Epochs $via$ $\mathrm{GWInSpect}$

    Swagat S. Mishra🇬🇧 · Athul K. Soman🇮🇹

    The expansion history of the Universe prior to Big Bang Nucleosynthesis (BBN) remains largely unconstrained. The high-energy post-inflationary era may involve multiple distinct epochs, each characterized by a different equation of state (EoS). A key prediction of inflation is the generation of tensor perturbations that later manifest as a stochastic background of primordial gravitational waves (GWs). The large-scale amplitude and small-scale spectral tilt ($n_{\mathrm{GW}}$) of these GWs encode the inflationary energy scale and the subsequent expansion history, respectively. A soft post-inflationary EoS ($w<1/3$) yields red-tilted GW spectra ($n_{\mathrm{GW}}<0$), while a stiff EoS ($w>1/3$) results in a blue-tilt ($n_{\mathrm{GW}}>0$). In our previous work [arXiv:2407.07956], we developed an analytical framework for computing the GW spectral energy density, ${\Omega }_{\mathrm{GW}}(f)$, for multiple post-inflationary transitions ($w_1\to w_2\to \cdots \to w_n\to 1/3$), focusing on the parameter space relevant for future GW observations. In this paper, we extend that framework to systematically investigate the $morphologicaldiversity$ of inflationary GW spectra generated by multi-epoch post-inflationary histories. Remaining model agnostic, we demonstrate that a wide variety of spectral shapes, ranging from convex and concave monotonic profiles to multi-peaked non-monotonic spectra, can naturally emerge depending on the sequence and duration of these epochs. We also introduce GWInSpect, a publicly available Python package that computes ${\Omega }_{\mathrm{GW}}(f)$ for arbitrary sequences of EoS transitions, providing a practical tool to study the pre-BBN expansion history of the Universe.

    ↳ astro-ph.COgr-qchep-phhep-th2 citations
27. 27*

    Scaling flow-based approaches for topology sampling in $\mathrm{SU}(3)$ gauge theory

    Claudio Bonanno🇪🇸 · Andrea Bulgarelli🇩🇪 · Elia Cellini🇮🇹 · Alessandro Nada🇮🇹 · Dario Panfalone🇮🇹 · Davide Vadacchino🇬🇧 · Lorenzo Verzichelli🇮🇹

    We develop a methodology based on out-of-equilibrium simulations to mitigate topological freezing when approaching the continuum limit of lattice gauge theories. We reduce the autocorrelation of the topological charge employing open boundary conditions, while removing exactly their unphysical effects using a non-equilibrium Monte Carlo approach in which periodic boundary conditions are gradually switched on. We perform a detailed analysis of the computational costs of this strategy in the case of the four-dimensional $\mathrm{SU}(3)$ Yang-Mills theory. After achieving full control of the scaling, we outline a clear strategy to sample topology efficiently in the continuum limit, which we check at lattice spacings as small as $0.045$ fm. We also generalize this approach by designing a customized Stochastic Normalizing Flow for evolutions in the boundary conditions, obtaining superior performances with respect to the purely stochastic non-equilibrium approach, and paving the way for more efficient future flow-based solutions.

    ↳ hep-latcond-mat.stat-mechcs.LGhep-phJHEP(2026)·16 citations
28. 28*

    Conformal gauge theory of vector-spinors and spin-3/2 particles

    Dario Sauro🇩🇪

    The unique off-shell fermionic gauge invariance of a vector-spinor field theory is found, and the invariant action is derived. The latter is Weyl invariant in any dimension in the massless limit, and it coincides with the singular point of the one-parameter family of Rarita-Schwinger Lagrangians, in agreement with previous findings in flat space. Pure gauge configurations are represented by gamma-trace vector-spinors, which can be gauged away in a global fashion. Previous claims that this theory is classically inconsistent are shown to be flawed, and the Velo-Zwanziger instability is proved to be absent. The theory propagates a massive spin-3/2 particle together with a spin-1/2 state whose mass is twice that of the j=3/2 mode. The causal construction of the quantum field is consistent with the field equations in that the ratio of the masses is the same, while it shows that the lower-spin component is a negative-norm state. The conformal anomaly is derived using known results for the heat kernel of nonminimal second-order operators, and the resulting $a$ charge is negative consistently with the Hofman-Maldacena bound, which applies only to unitary theories.

    ↳ hep-thgr-qchep-phPRD(2026)·1 citation
29. 29*

    The dark dimension, proton decay, and the length of the M-theory interval

    Mario Reig🇨🇭 · Ignacio Ruiz🇨🇭

    The existence of a large extra dimension in which only gravity propagates would have spectacular consequences for cosmology and laboratory experiments. In the strong coupling limit of the $E_8\times E_8$ heterotic string theory, the gauge and matter fields live at the end of the eleventh dimension, which becomes a natural candidate for a micron-size \textit{dark dimension}. In this work, however, we show that the length of the M-theory interval is severely constrained by proton decay searches. Our results indicate that in such constructions the size of the eleventh dimension is $R\lesssim \mathcal{O}(10^{-28})$ meters.

    ↳ hep-thhep-phJHEP(2026)·7 citations
30. 30*

    Electroweak form factors of large nuclei as BPS skyrmions

    Alberte Xosé López Freire · Christoph Adam🇪🇸 · Alberto García Martín-Caro🇪🇸 · Diego González Díaz🇪🇸

    We employ the Bogomolnyi-Prasad-Sommerfield (BPS) Skyrme model within the framework of semi-classical quantization as an effective model to compute both the electromagnetic and neutral current form factors for heavy nuclei. Our results show excellent agreement with the experimental data for low- to moderate momentum transfer. Further, we present an analytic expression of the neutral current form factor for generic nuclei, expressed as a power series in the momentum transfer. Our method provides an alternative to existing phenomenological approaches which, after fitting just one global radial parameter, allows for a surprisingly precise determination of the electroweak form factors at low momentum transfer for all heavy nuclei. Such a simple and robust description is particularly relevant for precision neutrino experiments, because it allows for a certain control over model-dependent systematics, which is essential for probing physics beyond the Standard Model.

    ↳ nucl-thhep-phhep-th1 citation

* 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.