Mon·Sep 22, 2025Monday·September 22, 2025

1. 01*

   Analytic two-loop amplitudes for di-jet and $\gamma +$jet production mediated by a heavy-quark loop

   Federico Coro🇧🇪 · Christoph Nega🇩🇪 · Lorenzo Tancredi🇩🇪 · Fabian J. Wagner🇩🇪

   In this paper, we present analytical results for the two-loop QCD corrections to the production of two partons or a photon and a parton in hadronic collisions, mediated by loops of massive quarks. These amplitudes involve Feynman integrals defined on an elliptic curve. We compute them by generalizing our recent results for the production of two photons to include additional crossings of the corresponding master integrals, which we compute in terms of the same basis of independent iterated integrals. We discuss the analytical properties of the amplitudes, highlighting the cancellations of a large number of elliptic differential forms in their finite remainders. Finally, we elaborate on a strategy for their numerical evaluation based on generalized series expansions at singular points of the physical amplitude, through the introduction of suitable sets of variables that allow us to resolve all singularities.

   hep-phhep-thJHEP(2026)·15 citations
2. 02*

   Hamiltonian truncation and quantum simulation of strong-field QED beyond tree level

   Patrick Draper🇺🇸 · Luis Hidalgo🇺🇸 · Anton Ilderton🇬🇧

   Quantum electrodynamics in strong background fields provides an interesting class of problems for classical and quantum simulation. In this paper we formulate simulations of polarization (helicity) flip for a photon colliding with a high-intensity plane wave. Polarization flip is a one loop effect, which requires addressing new issues that do not arise in simulations of tree-level processes. Working in the momentum-space Fock basis, while convenient for the extraction of scattering amplitudes, requires tuning counterterms to cancel large cutoff effects. We compute analytic formulas for the counterterms at one loop. We then construct circuits for quantum simulations of the process, perform noiseless simulations on classical computers to assess discretization errors, and discuss resource estimates for future simulations on quantum hardware.

   hep-phhep-latquant-phPRD(2026)·5 citations
3. 03*

   Hadronic tensor molecule $B_c^{\ast +}{B}_c^{\ast -}$

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

   Mass and full decay width of the hadronic tensor molecule ${\mathcal{M}}_{\mathrm{T}}=B_c^{\ast +}{B}_c^{\ast -}$ are examined in the framework of QCD sum rule method. To find the mass $m$ and current coupling $\Lambda$ of this state, we use the two-point sum rules. The result $(12.87\pm 0.08)\mathrm{GeV}$ for $m$ indicates that ${\mathcal{M}}_{\mathrm{T}}$ can easily decay to pairs of $J/\psi {\rm Y}$, ${\eta }_b{\eta }_c$, $B_c^{+}{B}_c^{-}$, and $B_c^{\ast +}{B}_c^{\ast -}$ mesons. Kinematically permitted ways for ${\mathcal{M}}_{\mathrm{T}}$ to transform to conventional mesons include also processes ${\mathcal{M}}_{\mathrm{T}}\to D^{(\ast )+}{D}^{(\ast )-}$, $D^{(\ast )0}{\overline{D}}^{(\ast )0}$, and $D_s^{(\ast )+}{D}_s^{(\ast )-}$ triggered by annihilation of $b\overline{b}$ quarks in the molecule. The decays to meson pairs $B^{(\ast )+}{B}^{(\ast )-}$, $B^{(\ast )0}{\overline{B}}^{(\ast )0}$ , and $B_s^{(\ast )0}{\overline{B}}_s^{(\ast )0}$ generated by $c\overline{c}\to$ light quarks are also among possible channels of the hadronic molecule ${\mathcal{M}}_{\mathrm{T}}$. Technical tools of the three-point sum rule approach are applied to compute partial widths of these decays. Our results for the mass and width ${\Gamma }_{{\mathcal{M}}_{\mathrm{T}}}=(154\pm 19)\mathrm{MeV}$ of the tensor molecule ${\mathcal{M}}_{\mathrm{T}}$ are important for experimental studies of fully heavy exotic structures.

   hep-phhep-exhep-latPLB(2025)·6 citations
4. 04*

   Reviving the energy-dependent partonic structure of $f_0(980)$ via two-pion distribution amplitudes

   Shan Cheng🇨🇳 · Ling-yun Dai🇨🇳 · Jian-ming Shen🇨🇳 · Shu-lei Zhang🇨🇳

   We present a novel framework for analyzing four-body semileptonic weak decays, performing the first high-twist analysis of the $D_s\to {\left[\pi \pi \right]}_{\mathrm{S}}$ form factors using light-cone distribution amplitudes for the isoscalar two-pion state ($2\pi$DAs). It is motivated by persistent tensions between phenomenological cascade analyses and QCD-based interpretations of the partonic structure of $f_0$ meson. Our study reveals that the twist-3 $2\pi$DAs incorporate an asymmetry in the partial-wave expansion, a feature absent in single $f_0$ distribution amplitudes, that drives a substantial cancellation between twist-2 and twist-3 contributions to the form factors. As a result, the predicted decay rate falls significantly below the experimental value. These findings indicate that the isoscalar two-pion system near the charm scale is not primarily a $q\bar{q}$ state, reviving the energy-dependent partonic structures of light scalar mesons by highlighting a fundamental limitation of the single-meson LCDA approach in describing such complex systems.

   hep-phPRD(2026)·5 citations
5. 05*

   ${\Xi }_c(3055)$ as a scaling point to establish the excited ${\Xi }_c^{(\prime )}$ family

   Xiao-Huang Hu🇨🇳 · Zhe-Tao Miu · Zi-Xuan Ma🇨🇳 · Qi Huang🇨🇳 · Yue Tan🇨🇳 · Jia-Lun Ping🇨🇳

   The low-lying orbital excitations of ${\Xi }_c^{(\prime )}$ baryons are studied within the chiral quark model combined with the ${}^3{P}_0$ decay mechanism. Motivated by the LHCb observation that ${\Xi }_c(3055)$ is a $\lambda$-mode $1D$ state with $J^P=3/2^{+}$, we take it as a reference to constrain model parameters and perform a systematic analysis of states below 3.1 GeV. Our results provide a consistent interpretation of the observed ${\Xi }_c$ spectrum: ${\Xi }_c(2790)$ and ${\Xi }_c(2815)$ are well described as a $\lambda$-mode $1P$ doublet, the structures around 2.9 GeV can be interpreted as $P$-wave excitations with mixed $\lambda /\rho$ modes, and ${\Xi }_c(2970)$ is consistent with a $2S$ assignment. Furthermore, ${\Xi }_c(3055)$ together with ${\Xi }_c(3080)$ forms a $\lambda$-mode $D$-wave doublet, while ${\Xi }_c(3123)$ favors a $1D$ assignment. These results provide a coherent picture of the low-lying ${\Xi }_c$ spectrum and call for further experimental tests.

   hep-phPRD(2026)·2 citations
6. 06*

   Searching for dark photon dark matter from terrestrial magnetic fields

   Kimihiro Nomura🇯🇵 · Atsushi Nishizawa🇯🇵 · Atsushi Taruya🇯🇵 · Yoshiaki Himemoto🇯🇵

   We present a novel search for dark photon dark matter (DM) using terrestrial magnetic field measurements at frequencies below 100 Hz. Coherently oscillating dark photon DM can induce a monochromatic magnetic field via kinetic mixing with ordinary photons. Notably, for dark photon masses $m_{A^{\prime }}$ around $3\times 10^{-14}$ eV, the signal can be resonantly amplified within a cavity formed by the Earth's surface and the ionosphere. We compute the expected signal incorporating the effect of atmospheric conductivity, and derive new upper limits on the kinetic mixing parameter $\epsilon$ from long-term geomagnetic data. These limits improve upon previous ground-based constraints in the mass range of $1\times 10^{-15}$ eV $\lesssim m_{A^{\prime }}\lesssim 2\times 10^{-13}$ eV.

   hep-phastro-ph.COPRD(2026)·6 citations
7. 07*

   Accessing nucleon transversity with one-point energy correlators

   Mei-Sen Gao🇨🇳 · Zhong-Bo Kang🇺🇸 · Wanchen Li🇨🇳 · Ding Yu Shao🇨🇳

   We propose a novel probe of the nucleon's transversity distribution, $h_1^q$, using the one-point energy correlator (OPEC), an infrared-and-collinear safe jet substructure observable. We demonstrate that in transversely polarized $p^{\uparrow }p$ collisions, the OPEC exhibits a single-spin asymmetry (SSA) with a clean $\sin ({\varphi }_s-{\varphi }_n)$ angular dependence. This method probes SSA over a much wider kinematic range in the angular scale ${\theta }_n$ compared to traditional measurements of hadron transverse momentum~$j_{\perp }$, establishing a complementary and systematically distinct channel to study the nucleon's three-dimensional structure at RHIC and the future Electron-Ion Collider.

   hep-phhep-exnucl-exnucl-thPRL(2026)·18 citations
8. 08*

   Hiding in Plain Sight, the electroweak ${\eta }_W$

   Giacomo Cacciapaglia🇫🇷 · Francesco Sannino🇩🇰 · Jessica Turner🇬🇧

   The presence of a topological susceptibility in the electroweak sector of the Standard Model implies the existence of a pseudoscalar state in the spectrum, ${\eta }_W$. We show that, within the Standard Model, no new particle is required to form this state. We identify the ${\eta }_W$ state with the CP-odd linear combination of the ground states of hydrogen and antihydrogen atoms.

   hep-phhep-thnucl-th4 citations
9. 09*

   Superconducting Strings in $E_6$

   Rinku Maji🇰🇷 · Qaisar Shafi🇺🇸

   We discuss the appearance of superconducting strings in $E_6$ grand unification, keeping track of the magnetic monopole flux that precedes the formation of the string flux tube. This flux matching ensures compatibility with the quantum tunneling of a monopole-antimonopole pair on a metastable string. We identify two realistic $E_6$ models with superconducting (metastable) strings that also carry zero modes of the right handed Majorana neutrinos and dark matter particles. Depending on the symmetry breaking scale associated with the strings, the latter could be a source of observable gravitational waves, intermediate scale dark matter, and the observed baryon asymmetry via leptogenesis. Topologically stable superconducting strings also appear if the $E_6$ symmetry breaking leaves unbroken the $Z_2$ subgroup of $Z_4$, the center of $SO(10)$. The zero modes of the SM fermions are the charge carriers in this case. Finally, the flux matching condition ensures that the Aharanov-Bohm phase change in going around the metastable strings is an integer multiple of $2\pi$ for all fields. The fields in the spinorial representation of SO(10) acquire a phase change of $\exp (\pm i\pi )$ if taken around the topologically stable $Z_2$ string.

   hep-phastro-ph.COhep-thPRD(2025)·4 citations
10. 10*

    The three-loop single-mass heavy-flavor corrections to the structure functions $F_2(x,Q^2)$ and $g_1(x,Q^2)$

    J. Ablinger🇦🇹 · A. Behring🇩🇪 · J. Blümlein🇩🇪 · A. De Freitas🇦🇹 · A. von Manteuffel🇩🇪 · C. Schneider🇦🇹 · K. Schönwald🇨🇭

    We present quantitative results on the single-mass heavy-flavor contributions in the region of large virtualities $Q^2$ up to three-loop order to the unpolarized structure function $F_2(x,Q^2)$ and the polarized structure function $g_1(x,Q^2)$ for the first time. These results are relevant for precision QCD analyses of the World deep-inelastic data and the data taken at future colliders, such as the Electron--Ion Collider, since the scaling violations due to massless and massive Wilson coefficients are significantly different. In order to measure the strong coupling constant ${\alpha }_s(M_Z^2)$ and the twist-2 parton distribution functions consistently at highest precision, the next-to-next-to-leading order corrections have to be taken into account. Furthermore, the complete three-loop corrections will allow to reduce the present theory error of the charm mass $m_c$ as measured form deep-inelastic data. We provide a fast and precise public numerical code for the unpolarized and polarized massive Wilson coefficients in the asymptotic region.

    hep-phhep-exPLB(2026)·11 citations
11. 11*

    Automatizing the search for mass resonances using BumpNet

    Jean-François Arguin🇨🇦 · Georges Azuelos🇨🇦 · Émile Baril🇨🇦 · Ilan Bessudo🇮🇱 · Fannie Bilodeau🇨🇦 · Maryna Borysova🇮🇱 · Shikma Bressler🇮🇱 · Samuel Calvet🇫🇷 · Julien Donini🇫🇷 · Etienne Dreyer🇮🇱 · Michael Kwok Lam Chu🇮🇱 · Eva Mayer🇫🇷 and 6 other authors

    Physics Beyond the Standard Model (BSM) has yet to be observed at the Large Hadron Collider (LHC), motivating the development of model-agnostic, machine learning-based strategies to probe more regions of the phase space. As many final states have not yet been examined for mass resonances, an accelerated approach to bump-hunting is desirable. BumpNet is a neural network trained to map smoothly falling invariant-mass histogram data to statistical significance values. It provides a unique, automatized approach to mass resonance searches with the capacity to scan hundreds of final states reliably and efficiently.

    hep-phhep-ex0 citations
12. 12*

    Sensitivity of seasonal variations of the muon energy spectrum in air showers to hadronic interaction models and the cosmic-ray mass composition

    Stef Verpoest🇺🇸 · Marisol Catalan Olais · Frank Schroeder🇺🇸

    The energy spectrum of muons produced in air showers depends not only on the properties of the primary particle, but also on the atmosphere. This is because of the competition between decay and interaction of the parent mesons, which depends on the atmospheric density. As a result, the number of muons at ground shows a seasonal variation, with the strength of the variation depending on the primary cosmic-ray energy, mass, as well as the energy of the detected muons. In this contribution, we study the variations of the muon energy spectrum in air showers using MCEq, a numerical solver of the cascade equations. In particular, we show how the amplitude of the seasonal variations of the number of high-energy (O(TeV)) muons in the shower depends on the primary energy, mass, as well as the assumed hadronic interaction model. A measurement of these variations is possible with the combination of a surface air-shower array and a deep underground detector, which provide a simultaneous measurement of the primary energy and the high-energy muon multiplicity, and may provide a new way to probe the cosmic-ray mass composition and hadronic interactions.

    ↳ astro-ph.HEhep-phPoS(2025)·0 citations
13. 13*

    The Impact of Muon and Pion Cooling on the Neutrino Spectrum of NGC 1068

    Carlos Blanco🇺🇸 · Dan Hooper🇺🇸 · Tim Linden🇸🇪 · Elena Pinetti🇺🇸

    The IceCube Neutrino Observatory has detected a flux of $\sim 1-10\mathrm{TeV}$ neutrinos from the active galaxy, NGC 1068. The soft spectral index of these neutrinos has previously been interpreted as an indication that this source accelerates protons only up to energies of several hundred TeV. Here, we propose that this source might instead accelerate protons to significantly higher energies, but that the charged pions and muons produced in their interactions undergo significant synchrotron energy losses before they can decay, leading to a cutoff in the neutrino spectrum at TeV-scale energies. This scenario would require very strong magnetic fields to be present in the acceleration region of NGC 1068, on the order of $B\sim 10^7\mathrm{G}$. We point out that this synchrotron cooling would impact the flavor ratios of the neutrinos from this source, providing a means to test this scenario with future very-large volume neutrino telescopes.

    ↳ astro-ph.HEastro-ph.GAhep-phPRD(2026)·8 citations
14. 14*

    Compressibility and speed of sound in magnetized nuclear matter with broken scale invariance

    Pallabi Parui🇮🇳 · Nilanjan Chaudhuri🇮🇳 · Pradip Roy🇮🇳 · Sourav Sarkar🇮🇳

    The thermodynamical properties of magnetized nuclear matter at finite temperature and baryon chemical potential are studied within an effective model incorporating the QCD trace anomaly effect. The presence of magnetic field induces anisotropic structure in the energy momentum tensor due to the broken rotational invariance. The study exhibits a phase transition through the sudden change of the effective nucleon mass in a certain range of baryon chemical potential and temperature. The addition of nucleonic vacuum contribution at finite magnetic field leads to the magnetic catalysis effect. The change in squared speed of sound with chemical potential at various temperatures is closely connected to the nature of phase transition in nuclear matter. The pressure anisotropy results in different values of sound speed and isothermal compressibility in the parallel and perpendicular directions with respect to the magnetic field. The smaller values of isothermal compressibility in the parallel direction compared to the perpendicular one indicate that the equation of state is stiffer along the magnetic field direction. The studies of these thermodynamic observables can have significant importance in analyzing the properties of some compact astrophysical objects as well as in the context of non-central heavy ion collision experiments.

    ↳ nucl-thhep-phPRD(2025)·2 citations
15. 15*

    Quantum Metric Corrections to Liouville's Theorem and Chiral Kinetic Theory

    Kazuya Mameda🇯🇵 · Naoki Yamamoto🇯🇵

    Quasiparticles may possess not only Berry curvature but also a quantum metric in momentum space. We develop a canonical formalism for such quasiparticles based on the Dirac brackets, and demonstrate that quantum metric modifies the phase-space density of states at $\mathcal{O}({\hslash }^2)$, leading to corrections to Liouville's theorem, kinetic theory, and related physical quantities. In particular, we show that, in the presence of an inhomogeneous electric field, quantum metric induces corrections to the energy density and energy current. Applied to chiral fermions, this framework provides a nonlinear extension of chiral kinetic theory consistent with quantum field theory. Our work paves the way to potential applications of the quantum metric in high-energy physics and astrophysics.

    ↳ hep-thcond-mat.mes-hallcond-mat.str-elgr-qc+16 citations
16. 16*

    Detecting milli-Hz gravitational waves with optical resonators

    G. Barontini🇬🇧 · X. Calmet🇬🇧 · V. Guarrera🇬🇧 · A. Smith🇬🇧 · A. Vecchio🇬🇧

    We propose a gravitational wave detector based on ultrastable optical cavities enabling the detection of gravitational wave signals in the mostly unexplored $10^{-5}-1$ Hz frequency band. We illustrate the working principle of the detector and discuss that several classes of gravitational wave sources, both of astrophysical and cosmological origin, may be within the detection range of this instrument. Our work suggests that terrestrial gravitational wave detection in the milli-Hz frequency range is potentially within reach with current technology.

    ↳ astro-ph.IMgr-qchep-phhep-th+1Class.Quant.Grav.·2 citations
17. 17*

    A Unified Neural-Network Framework for Nucleon Imaging from Numerical Simulations of QCD

    Min-Huan Chu🇵🇱 · Krzysztof Cichy🇵🇱 · Martha Constantinou🇺🇸 · Paweł Sznajder🇵🇱 · Jakub Wagner🇵🇱

    Parton distributions encode the momentum-space structure and, in their generalizations, the spatial tomography of quarks and gluons inside hadrons, the building blocks of visible matter. We present a unified neural-network approach that learns these distributions directly from matrix elements calculated via numerical simulations of quantum chromodynamics (QCD) on the lattice by fitting two complementary inputs simultaneously: data matched to physical quantities via known momentum-space and coordinate-space formalisms. Utilizing data from both methods stabilizes the extraction and mitigates biases that can arise when either is used alone. We validate the method on controlled mock data and apply it to lattice-QCD matrix elements to extract parton distribution functions (PDFs). We show benefits of such an approach for determining the physical quantities. We further extend the framework to zero-skewness generalized parton distributions and demonstrate nucleon tomography within the same neural-network parameterization. Our results provide an adaptable and systematically improvable approach for extracting partonic distributions from Euclidean correlators. It can incorporate polarization, additional channels, and future experimental constraints from current and future facilities, such as the Electron-Ion Collider.

    ↳ hep-lathep-exhep-phJHEP(2026)·15 citations
18. 18*

    Why Do We See So Few Black Holes in Massive Binaries?

    S.Karpov · V.Lipunov

    We offer a simple explanation for the small number of black holes observed in pairs with massive stars. In detached massive binaries, spherically symmetric accretion takes place. This accretion could result in effective energy release in the hard band only if the equipartition of the gravitational and magnetic energy of plasma is established (Shvartsmans theorem). However, we show that due to the magnetic exhaust effect this equilibrium is virtually never established for the actual magnetic fields observed on massive stars: Shvartsmans theorem does not work. As a result, it is virtually impossible to detect black holes in detached massive binaries by currently available means (mainly, through X-ray observations).

    ↳ astro-ph.HEhep-phAstron.Lett.(2001)·6 citations
19. 19*

    ${\eta }_{\mathrm{w}}$-meson from topological properties of the electroweak vacuum

    Gia Dvali🇩🇪 · Archil Kobakhidze🇦🇺 · Otari Sakhelashvili🇩🇪

    We further scrutinize the evidence for a recently suggested pseudo-scalar particle, the electroweak ${\eta }_{\mathrm{w}}$-meson. Its existence is demanded by matching the removal of the weak vacuum angle ${\theta }_{\mathrm{w}}$ by the anomalous $B+L$ - symmetry with a massive pole in the topological susceptibility of the vacuum. We specifically focus on the possibility of the emergence of ${\eta }_{\mathrm{w}}$ as a collective excitation of the phase of the condensate of the 't Hooft fermion determinant, generated by the electroweak instantons, which breaks the $B+L$ - symmetry spontaneously. We argue that the generation of the 't Hooft vertex is in one-to-one correspondence with its non-zero vacuum expectation value which is cutoff insensitive. We outline certain puzzles about the nature of the emergent ${\eta }_{\mathrm{w}}$ which require further investigations.

    ↳ hep-thgr-qchep-phmath-ph+1PRD(2025)·11 citations
20. 20*

    Analytic derivation of GW spectrum from bubble collisions in FLRW Universe

    Masaki Yamada🇯🇵

    We generalize the analytic formula for the gravitational-wave spectrum from bubble collisions during a cosmological first-order phase transition, under the thin-wall and envelope approximations, by incorporating the effect of cosmic expansion in the FLRW metric. Along with presenting the complete analytic expression and corresponding numerical results, we also derive simplified formulas valid in the large- and small-$k$ limits, as well as in the Minkovski limit. The latter expansion reveals that the Minkovski approximation breaks down for $\beta /H_{\ast }\lesssim 10$, where $\beta$ denotes the inverse duration of the phase transition and $H_{\ast }$ the Hubble parameter at its completion. Furthermore, the next-to-leading-order term contributes about a $10\%$ correction for $\beta /H_{\ast }\sim 140$, a typical value for the electroweak phase transition.

    ↳ astro-ph.COgr-qchep-phPRD(2026)·10 citations
21. 21*

    Pair luminosity and cooling of newborn strange star: unpaired quarks

    Mikalai Prakapenia🇧🇾 · Gregory Vereshchagin🇧🇾

    It was shown that pair luminosity of the newborn strange star with temperature of $10^{11}$ K may be as high as $L_{\pm }\simeq 10^{52}$ erg/s. The question remains: can a strange star maintain such a high surface temperature for a long time? To answer this question we studied thermal evolution of newborn strange star made of unpaired quarks taking into account its thermal conductivity and neutrino emission by the URCA processes $d\to u+e+{\bar{\nu }}_e$ and $u+e\to d+{\nu }_e$. Our results show that extremely high luminosity due to the Schwinger process and insufficient thermal conductivity of quarks leads to development of steep temperature gradient at the surface of strange star. As a result, the temperature at the surface and hence its luminosity decreases, reaching $10^{43}$ erg/s already at $10^2$ seconds. This result holds even in the presence of neutrinosphere.

    ↳ astro-ph.HEhep-phPRD(2026)·1 citation
22. 22*

    Probing QGP using local charge fluctuations in heavy-ion collisions

    Jonathan Parra🇺🇸 · Roman Poberezhniuk🇺🇸 · Volker Koch🇺🇸 · Claudia Ratti🇺🇸 · Volodymyr Vovchenko🇺🇸

    We revisit the D-measure of event-by-event net-electric charge fluctuations, an idea first introduced over 20 years ago as a potential signature for the presence of quark-gluon plasma (QGP) in heavy-ion collisions. We developed a quantitative framework that incorporates resonance-decay effects, global and local charge conservation, and experimental kinematic cuts. Folding these effects into a formalism of density correlations yields an improved expression for the $D$-measure inside acceptance. We make comparisons with ALICE data for Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$~TeV. We find that a hadron-gas scenario can describe the data only for a very short charge conservation range, while a QGP scenario is in good agreement with the measurement and is relatively insensitive to the charge conservation range. A Bayesian comparison of both scenarios shows moderate evidence for freeze-out of charge fluctuations in the QGP phase.

    ↳ nucl-thhep-phEPJ Web Conf.(2026)·1 citation
23. 23*

    Cosmographic Footprints of Dynamical Dark Energy

    Elisa Fazzari🇮🇹 · William Giarè🇬🇧 · Eleonora Di Valentino🇬🇧

    We introduce a novel cosmographic framework to trace the late-time kinematics of the Universe without assuming any underlying dynamics. The method relies on generalized Padé-$(2,1)$ expansions around arbitrary pivot redshifts, which, compared to state-of-the-art calculations, reduce truncation errors by up to two orders of magnitude at high redshift and yield more precise constraints by defining cosmographic parameters exactly where the data lie. This avoids extrapolations, mitigates degeneracies, and enables a clean disentangling of their effects. Using the latest low-redshift datasets, we center the generalized expansion in multiple bins across $z\in [0,1]$ and obtain precise constraints on the redshift evolution of cosmographic parameters. We find that all key parameters deviate from their $\Lambda$CDM predictions in a redshift-dependent way that can be naturally explained within dynamical Dark Energy scenarios. The deceleration parameter $q(z)$ follows a redshift evolution consistent with the Chevallier-Polarski-Linder (CPL) parameterization, while the generalized $Om(z)$ diagnostic shows deviations of up to $\sim 4\sigma$ from the constant $\Lambda$CDM expectation, closely matching the CPL predictions. Taken together, these results point to footprints of dynamical Dark Energy in the kinematics of the Universe at $z\lesssim 1$.

    ↳ astro-ph.COhep-phApJL(2026)·64 citations
24. 24*

    New determination of the neutrino hadronic production cross sections from GeV to beyond PeV energies

    Luca Orusa🇺🇸 · Mattia Di Mauro🇮🇹 · Fiorenza Donato🇮🇹

    The flux of astrophysical neutrinos is now measured with unprecedented accuracy and over several decades of energy spectrum. Their origin traces back to hadronic collisions between protons and nuclei in the cosmic rays with hydrogen and helium in the target gas. To accurately interpret the data, a precise determination of the underlying cross sections is therefore mandatory. We present a new evaluation of the neutrino production cross section from $p+p$ collisions, building on our previous analysis of the production cross section for ${\pi }^{\pm }$, $K^{\pm }$, and minor baryonic and mesonic channels. Cross sections for scatterings involving nuclei heavier than protons are also derived. The novelty of our approach is the analytical description of the Lorentz invariant cross section ${\sigma }_{\mathrm{inv}}$, and the fit of the model to the available accelerator data. We work with neutrino energies from $10$ GeV to $10^7$ GeV, and, correspondingly, to incident proton (nuclei) energies from $10$ GeV to $10^9$ GeV (GeV/n). We obtain the total differential cross section, $d\sigma (p+p\to \nu +X)/d{E}_{\nu }$ as a function of neutrino and proton energies, with an estimated uncertainty of 5% for neutrino energies below 100 GeV, increasing to 10% above TeV energies. Predictions are given for ${\nu }_e,{\nu }_{\mu },\overline{{\nu }_e}$ and $\overline{{\nu }_{\mu }}$. A comparison with state-of-the-art cross sections, all relying on Monte Carlo generators, is also presented. To facilitate the use by the community, we provide numerical tables and a script for accessing our energy-differential cross sections.

    ↳ astro-ph.HEhep-phPRD(2026)·2 citations
25. 25*

    Neutrinos from core-collapse supernovae

    Georg G. Raffelt (MPP)🇩🇪 · Hans-Thomas Janka (MPA)🇩🇪 · Damiano F. G. Fiorillo (DESY Zeuthen)🇩🇪

    The core of a massive star (M > 8 Msun) eventually collapses. This implosion usually triggers a supernova (SN) explosion that ejects most of the stellar envelope and leaves behind a neutron star (NS) with a mass of up to about 2 Msun. Sometimes the explosion fails and a black hole forms instead. The NS radiates its immense binding energy (some 10% of its rest mass or $2-4\times 10^{53}$ erg) almost entirely as neutrinos and antineutrinos of all flavors with typical energies of some 10 MeV. This makes core-collapse SNe the most powerful neutrino factories in the Universe. Such a signal was observed once - with limited statistics - from SN 1987A in the Large Magellanic Cloud. Today, however, many large neutrino detectors act as SN observatories and would register a high-statistics signal. A future Galactic SN, though rare (1-3 per century), would produce a wealth of astrophysical and particle-physics information, including possible signatures for new particles. Neutrinos are key to SN dynamics in the framework of the Bethe-Wilson delayed explosion paradigm. After collapse, they are trapped in the core for a few seconds, forming a dense neutrino plasma that can exhibit collective flavor evolution caused by the weak interaction, a subject of intense theoretical research.

    ↳ astro-ph.HEhep-ph35 citations
26. 26*

    Spectral instability of horizonless compact objects within astrophysical environments

    Kyriakos Destounis🇵🇹 · Mateus Malato Corrêa🇧🇷 · Caio F. B. Macedo🇧🇷 · Rodrigo Panosso Macedo🇩🇰

    Recent non-modal analyses have uncovered spectral instabilities in the quasinormal-mode spectrum of black holes; a phenomenon that intriguingly extends to spherically-symmetric exotic compact objects. These results point to a sensitivity of the spectrum with potentially far-reaching implications for black-hole spectroscopy. At the same time, growing attention has turned to astrophysical environments around compact objects and their role in shaping gravitational-wave astrophysics. In this work, we establish a direct link between spectral instabilities and environmental effects by modeling matter as a localized bump outside the light ring of a spectrally-unstable exotic compact object with a purely reflective surface. We find that while such environments can destabilize the fundamental quasinormal modes of loosely-compact exotic objects, the fundamental modes of ultra-compact horizonless objects remain remarkably robust. In contrast, overtones are shown to develop spectral instabilities in the presence of the bump. By tracking both interior modes, trapped between the light ring and the surface of the exotic compact object, and exterior modes, confined between the bump and the light ring, we uncover an overtaking instability in which ``unperturbed'' exterior overtones metamorphose into ``perturbed'' fundamental modes as the bump moves outward. Finally, we demonstrate that environmental effects, while capable of further amplifying spectral instabilities, cannot induce next-to-leading-order perturbations strong enough to trigger a modal instability.

    ↳ gr-qcastro-ph.HEhep-phhep-thPRD(2026)·16 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.