Fri·Jan 24, 2025Friday·January 24, 2025

1. 01*

   Type-III Scotogenic Model: Inflation, Dark Matter and Collider Phenomenology

   Labh Singh🇮🇳 · Rahul Srivastava🇮🇳 · Surender Verma🇮🇳 · Sushant Yadav🇮🇳

   We investigate an extension of the Type-III scotogenic model by incorporating a real singlet scalar. This scalar plays a crucial role as the inflaton due to its non-minimal coupling with the Ricci scalar. The inflaton field subsequently decays into other particles within the Type-III scotogenic framework. In this framework, the inert scalar doublet and fermion triplet are crucial for neutrino mass generation and present strong candidates for 25\% energy budget or dark matter in the Universe. We study their relic abundance and potential for direct detection. Furthermore, we discuss possible observational signals that could be identified in future collider experiments.

   hep-phgr-qchep-exPRD(2025)·9 citations
2. 02*

   Renormalization of general Effective Field Theories: Formalism and renormalization of bosonic operators

   Renato M. Fonseca🇪🇸 · Pablo Olgoso🇮🇹 · José Santiago🇪🇸

   We describe the most general local, Lorentz-invariant, effective field theory of scalars, fermions and gauge bosons up to mass dimension 6. We first obtain both a Green and a physical basis for such an effective theory, together with the on-shell reduction of the former to the latter. We then proceed to compute the renormalization group equations for the bosonic operators of this general effective theory at one-loop order.

   hep-phJHEP(2025)·22 citations
3. 03*

   Distribution Functions of a Radially Excited Pion

   Z.-N. Xu🇪🇸 · Z.-Q. Yao🇪🇸 · D. Binosi🇮🇹 · M. Ding🇨🇳 · C. D. Roberts🇨🇳 · J. Rodríguez-Quintero🇪🇸

   A nonperturbatively-improved, symmetry-preserving approximation to the quantum field equations relevant in calculations of meson masses and interactions is used to deliver predictions for all distribution functions (DFs) of the ground state pion, ${\pi }_0$, and its first radial excitation, ${\pi }_1$, viz. valence, glue, and sea. Regarding Mellin moments of the valence DFs, the $m=0,1$ moments in both states are identical; but for each $m\ge 2$, that in the ${\pi }_0$ is greater than its partner in the ${\pi }_1$. Working with such information, pointwise reconstructions of the hadron-scale ${\pi }_{0,1}$ valence DFs are developed. The predicted ${\pi }_0$ valence DF is consistent with extant results. The ${\pi }_1$ valence DF is novel: it possesses three-peaks, with the central maximum partnered by secondary peaks on either side, each separated from the centre by a zero: the zeroes lie at $x\approx 0.2,0.8$ and the secondary peaks at $x\approx 0.1,0.9$. Evolution to $\zeta =3.2$GeV, a typical scale for nonperturbative calculations, is accomplished using an evolution scheme for parton DFs that is all-orders exact. At this higher scale, differences between the ${\pi }_{0,1}$ valence DFs remain significant, but analogous differences between glue and sea DFs are far smaller. This analysis shows that, owing to constraints imposed by chiral symmetry and the pattern by which it is broken in Nature, there are noticeable differences between the structural properties of the pion ground state and its radial excitations.

   hep-phhep-exhep-latnucl-ex+1EPJC(2025)·7 citations
4. 04*

   Tetraquarks in the Born-Oppenheimer approximation

   Davide Germani🇮🇹 · Benjamin Grinstein🇺🇸 · Antonio Davide Polosa🇮🇹

   The conventional loosely bound molecule interpretation of the $X(3872)$ is not compatible with the recent LHCb experimental measurement of the ratio of branching fractions $\mathcal{R}=\text{Br}(X\to {\psi }^{\prime }\gamma )/\text{Br}(X\to \psi \gamma )$. We systematically determine the entire tetraquark spectrum for $J=0,1,2$ and refine the calculation of $\mathcal{R}$ in an improved Born-Oppenheimer description of the $X(3872)$ compact tetraquark. This refinement yields a significantly better agreement with experimental data on $\mathcal{R}$ and on the spectroscopy of the states themselves. Extending the diquark-antidiquark paradigm to encompass tetraquarks that are linear superposition of open charm singlets and color octets, we discover that these exotic resonances manifest as compact shallow bound states of quarks in color force potentials.

   hep-phJHEP(2025)·12 citations
5. 05*

   CosmiXs: Improved spectra for dark matter indirect detection

   Chiara Arina🇧🇪 · Mattia Di Mauro🇮🇹 · Nicolao Fornengo🇮🇹 · Jan Heisig🇩🇪 · Adil Jueid🇰🇷 · Roberto Ruiz de Austri🇪🇸

   The spectra of stable particles produced from dark matter (DM) are one of the most important ingredients to calculate the fluxes for DM indirect detection experiments. At energies above a few GeV, most of the particles are produced following a complex sequence of phenomena including resonance decays, QED and QCD final-state radiation, radiation of weak gauge bosons, hadronization and hadron decays. In this contribution, we discuss improvements on the calculation of the energy spectra at the source using state-of-the-art tools that include effects that were not taken previously into account. We include helicity information of the particles produced in the annihilation channels, which leads to proper inclusion of electroweak radiation during the entire showering history. These effects are taken into account using the Vincia, which is based on the helicity-dependent antenna shower formalism. Off-shell contributions are also taken into account for annihilation channels into $WW$ and $ZZ$ through the four-body processes into fermions and for DM masses below the gauge boson mass. We also revisit the tune of the Lund fragmentation function parameters in Pythia using LEP data at the $Z$-boson pole. The spectra of cosmic messengers are provided for DM masses between 5 GeV and 100 GeV and are publicly distributed in this \href{https://github.com/ajueid/CosmiXs.git}{GitHub repository}.

   hep-phastro-ph.HE1 citation
6. 06*

   Probing new light scalars with the lepton anomalous magnetic moment and the weak equivalence principle violation

   Xitong Mei🇨🇳 · Dongfeng Gao🇨🇳 · Wei Zhao🇨🇳 · Jin Wang🇨🇳 · Mingsheng Zhan🇨🇳

   A new scalar particle with generic couplings to the standard-model particles is a possible source for the lepton anomalous magnetic moment and the violation of the weak equivalence principle. Here, one-loop contributions to the lepton anomalous magnetic moment, involving the scalar-photon and scalar-lepton couplings, are calculated. Then, employing the recent experimental results of the electron anomalous magnetic moment, the muon anomalous magnetic moment, and the MICROSCOPE mission, we find the improved constraints on scalar-lepton and scalar-photon couplings: $|{\lambda }_e|\le 6.0\times 10^{-6}$, $|{\lambda }_{\mu }|\le 3.5\times 10^{-4}$, and $|{\lambda }_{\gamma }|\le 4.5\times 10^{-13}$ $\mathrm{e}{\mathrm{V}}^{-1}$ for scalar mass below $10^4$ eV. We find that the naive scaling relationship between the scalar-muon coupling and the scalar-electron coupling is favored by three experimental results. Furthermore, the minimal standard-model extension by one scalar is also favored by all three experiments, and the model parameter is constrained best to $|\mathcal{A}|\le 1.7\times 10^{-11}$ eV for $m_{\varphi }<10^{-13}$ eV.

   hep-phgr-qcEPJC(2025)·0 citations
7. 07*

   Gluon polarization contribution to the spin alignment of vector mesons from holography

   Hiwa A. Ahmed🇨🇳 · Yidian Chen🇨🇳 · Mei Huang🇨🇳

   We investigate the behaviour of vector mesons $\rho$, $\varphi$, and $J/\Psi$ in both non-rotating and rotating thermal media using the soft-wall holographic QCD model with four flavours. By incorporating anisotropic backgrounds derived from the Einstein-Maxwell-dilaton action, we incorporate rotational effects via a $U(1)$ gauge field, and the induced polarization of gluons is described by a rotation dependent dilation field. Spectral function analysis reveals that $\rho$ and $\varphi$ mesons exhibit broad peaks at lower temperatures, indicating their presence in the medium, while these peaks disappear at higher temperatures. Rotation delays this melting process, increasing the dissociation temperature. In contrast, the $J/\Psi$ meson, owing to its heavy charm quark content, demonstrating its resilience to thermal effects. We further explore the global spin alignment of these mesons in the event plane frame. For the $\varphi$ meson, the averaged ${\rho }_{00}$ over the full range of azimuthal angle shows weak temperature dependence at low transverse momentum ($p_T$) but significant suppression at high $p_T$, aligning with experimental observations. Rotation enhances ${\rho }_{00}$ at high $p_T$, a phenomenon attributed to angular momentum transfer via spin-orbit coupling. The $J/\Psi$ meson, however, displays insensitivity to temperature and rotation up to $p_T=5$ GeV, with a very small suppression observed at higher $p_T$, likely due to its heavy quark nature. Although $\rho$ meson spin alignment is not yet experimentally measured, it exhibits behaviour qualitatively similar to the $\varphi$ meson, with thermal fluctuations dampening alignment and rotation enhancing it.

   hep-phPRD(2025)·8 citations
8. 08*

   A systematic investigation on vector dark matter-nucleus scattering in effective field theories

   Jin-Han Liang🇨🇳 · Yi Liao🇨🇳 · Xiao-Dong Ma🇨🇳 · Hao-Lin Wang🇨🇳

   In this paper, we systematically investigate the general spin-one dark matter-nucleus interactions within the framework of effective field theories (EFT). We consider both the nonrelativistic (NR) and the relativistic EFT descriptions of the DM interactions with nucleons and quarks. In the NREFT framework, we present a complete list of NR operators for spin-one DM coupling to nucleons and compute their contributions to the DM response functions. Next, we consider all possible leading-order relativistic EFT operators between DM and light quarks and the photon, and perform NR reductions to match them onto the NREFT. We then derive the nuclear scattering rate from these interactions, and employ recent DM direct detection data (from both the nuclear recoil and the Migdal effect) to constrain all these EFT operators and DM electromagnetic properties. We find the elastic nuclear recoil data (from PandaX-4T, XENONnT, LZ, and DarkSide-50) set stringent bounds on the EFT coefficients for a DM mass above a few GeV while the Migdal effect datasets (from PandaX-4T, XENONnT, and DarkSide-50) can probe the DM mass region as small as 20 MeV. Lastly, we construct a UV complete model that can provide a complex spin-one DM candidate, and at the same time generate DM-quark/photon operators discussed in this work.

   hep-phPRD(2025)·6 citations
9. 09*

   Testing the hypothesis of vector X17 boson by D meson, Charmonium, and $\varphi$ meson decays

   Fei-Fan Lee🇨🇳 · Lam Thi Thuc Uyen🇹🇼 · Guey-Lin Lin🇹🇼

   The recent ATOMKI experiments provided evidence pointing towards the existence of an X17 boson in the anomalous nuclear transitions of Beryllium-8, Helium-4, and Carbon-12. In this work, we consider X17 boson contributions to the previously measured $D$ meson decays which include $D_s^{\ast +}\to D_s^{+}{e}^{+}{e}^{-}$, $D_s^{\ast +}\to D_s^{+}\gamma$, $D^{\ast 0}\to D^0{e}^{+}{e}^{-}$, and $D^{\ast 0}\to D^0\gamma$, as well as the measured decays of $\psi (2S)\to {\eta }_c{e}^{+}{e}^{-}$, $\psi (2S)\to {\eta }_c\gamma$, $\varphi \to \eta e^{+}{e}^{-}$, and $\varphi \to \eta \gamma$. Using the data of the above meson decays, we perform a fitting to the coupling parameters ${\epsilon }_u,{\epsilon }_c$, and ${\epsilon }_s$ by treating the couplings ${\epsilon }_u$ and ${\epsilon }_c$ as independent from each other rather than assuming the generation universality ${\epsilon }_u={\epsilon }_c$. It is found that the above fitting renders $|{\epsilon }_c|=7.6\times 10^{-3}$, $|{\epsilon }_s|=2.4\times 10^{-3}$ and a huge magnitude for ${\epsilon }_u$, which is in serious tension with $\left|{\epsilon }_u\right|$ determined from ATOMKI measurements. Using our fitted range for ${\epsilon }_c$ and the range for ${\epsilon }_d$ from ATOMKI measurements, we predict the range for $D^{\ast +}\to D^{+}{e}^{+}{e}^{-}$ decay rate.

   hep-phhep-exEPJC(2026)·4 citations
10. 10*

    Analysis of inflationary models in higher-dimensional uniform inflation

    Takuya Hirose🇯🇵

    We consider higher-dimensional uniform inflation, in which the extra dimensions expand at the same rate as three-dimensional non-compact space during inflation. We compute the cosmological perturbation in $D+4$ dimensions and derive the spectral index $n_s$ and the tensor-scalar ratio $r$. We analyze five inflationary models: chaotic inflation, natural inflation, quartic hilltop inflation, inflation with spontaneously broken SUSY, and $R^2$ inflation. By combining the results from these models with the Planck 2018 constraints, we discuss that it is not desirable for the extra-dimensional space to expand at the same rate as the three-dimensional non-compact space, except for the case of one extra dimension.

    hep-phastro-ph.COhep-thJHEP(2025)·9 citations
11. 11*

    Dark Photon Polarimetry

    Fiesta Ting Yan Leung · Tao Liu🇨🇳 · Sida Lu🇨🇳 · Jing Ren🇨🇳 · Cheuk Kan Kelvin Yue · Kaifeng Zheng

    We propose detecting dark photons (DP), a major candidate for wave dark matter, through polarimetry. The DP can modify Maxwell's equations due to its kinetic mixing with regular photons, inducing an oscillating component in the electromagnetic field. This may leave an imprint on polarimetric light signals, such as Faraday rotation, characterized by a distinctive wave pattern in spacetime. We then apply this method to investigate ultralight DPs produced through the superradiance of supermassive black holes for demonstration. Using the polarimetric measurements of radiation from the M87${}^{\ast }$ and Sgr A${}^{\ast }$ at the Event Horizon Telescope, we show that novel limits on the photon-DP mixing parameter can be set for the rarely-explored DP mass ranges: explicitly $10^{-22}-10^{-20}$eV with the best reach of $\sim 10^{-8}$ achieved at $\sim 10^{-20}$eV, and $10^{-19}-10^{-17}$eV with the best reach of $\sim 10^{-11}$ achieved at $\sim 10^{-17}$eV. Given the universality of its underlying physics, we expect DP polarimetry to be broadly applicable for DP detection in laboratory experiments and astronomical observations.

    hep-ph1 citation
12. 12*

    Apples to Apples in Jet Quenching: robustness of Machine Learning classification of quenched jets to Underlying Event contamination

    João Arruda Gonçalves🇵🇹 · José Guilherme Milhano🇵🇹

    Progress in the theoretical understanding of parton branching dynamics within an expanding Quark Gluon Plasma relies on detailed and fair comparisons with experimental data for reconstructed jets. Such comparisons are only meaningful when the computed jet, be it analytically or via event generation, accounts for the complexity of jets reconstructed in the challenging environment of heavy-ion collisions. Jet reconstruction in heavy ion collisions involves a necessarily imperfect subtraction of the large and fluctuating underlying event: reconstructed jets always include underlying event contamination. To identify true jet quenching effects, modifications due to the interaction of the branching partonic system with the Quark Gluon Plasma, we establish a baseline that accounts for possible background contamination on unmodified jets. In practical terms, jet quenching effects are only those not present in jets produced in proton-proton collisions that have been embedded in a realistic heavy-ion background and where subtraction has been carried out analogously to that in the heavy ion case. With this setup, we assess the sensitivity to underlying event of commonly discussed jet quenching observables and its impact on the robustness of Machine Learning studies, aimed at classifying jets according to their degree of modification by the Quark Gluon Plasma, that rely on those observables. We find the discrimination power of a simple Boosted Decision Tree to be robust in the realistic scenario where both medium response and underlying event are present, giving support to portability to the experimental context.

    hep-phJHEP(2025)·4 citations
13. 13*

    Chiral Effective Field Theories for Strong and Weak Dynamics

    Hao Sun🇨🇳 · Yi-Ning Wang🇨🇳 · Jiang-Hao Yu🇨🇳

    The chiral effective field theory (ChEFT) is an extension of the chiral perturbation theory that includes the nuclear forces and weak currents at the hadronic and nuclear scales. We propose a systematic framework of parametrising the pion-nucleon and nucleon-nucleon Lagrangian via the Weinberg power counting rules. We enumerate the operator bases of ChEFT by extending the Hilbert series of the pure meson sector to the nucleon sector with the CP symmetries. The Young tensor method is utilized to obtain the complete sets of the nucleon-nucleon, three-nucleon operators with/without pions ($/\pi$-EFT). Then we use the spurion technique to reconstruct the ChEFT Lagrangian by taking the adjoint spurion and leptonic fields as the building blocks, without the need of external sources. These operators can be applied to both the strong dynamics, and the nucleon/nuclear weak current processes.

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

    Precise Predictions for Event Shapes in Diphoton Production at the LHC

    Federico Buccioni🇩🇪 · Xuan Chen🇨🇳 · Wei-Jie Feng🇨🇭 · Thomas Gehrmann🇨🇭 · Alexander Huss🇨🇭 · Matteo Marcoli🇬🇧

    Photon pair production is an important benchmark process at the LHC, entering Higgs boson studies and new physics searches. It has been measured to high accuracy, allowing for detailed studies of event shapes in diphoton final states. To enable precision physics with diphoton event shapes, we compute the second-order QCD corrections, $\mathcal{O}({\alpha }_s^3)$, to them and study their phenomenological impact.

    hep-phPRL(2025)·14 citations
15. 15*

    A plethora of long-range neutrino interactions probed by DUNE and T2HK

    Sanjib Kumar Agarwalla🇮🇳 · Mauricio Bustamante🇩🇰 · Masoom Singh🇮🇳 · Pragyanprasu Swain🇮🇳

    The next-generation neutrino oscillation experiments would be sensitive to the new neutrino interactions that would strengthen the search for physics beyond the Standard Model. In this context, we explore the capabilities of the two leading future long-baseline neutrino oscillation experiments, DUNE and T2HK, to search for new flavor-dependent neutrino interactions with electrons, protons, and neutrons that could potentially modify neutrino flavor transitions. We forecast their sensitivities in the context of long-range neutrino interactions mediated by a neutral vector boson lighter than $10^{-10}$ eV and sourced by the vast amount of nearby and distant matter in the Earth, Moon, Sun, Milky Way, and local Universe. For the first time, we explore a plethora of $U(1{)}^{\prime }$ symmetries inducing the new interactions built from the combination of lepton and baryon numbers. We find that in all cases, DUNE and T2HK may constrain or discover the existence of new long-range neutrino interaction, and in some favorable cases, may identify the new $U(1{)}^{\prime }$ symmetry responsible for it. In this short proceeding, we only summarize the prospects of constraining the new interaction in case of all our candidate $U(1{)}^{\prime }$ symmetries, which have been discussed in JHEP 09 (2024) 055.

    hep-phhep-exphysics.ins-det0 citations
16. 16*

    Comparison of Three Methods for Triggering Core-collapse Supernova Explosions in Spherical Symmetry

    Liliya Imasheva (1,2) · H.-Thomas Janka (1)🇩🇪 · Achim Weiss (1,2) ((1) MPI Astrophysics, Garching, (2) LMU Munich)

    Despite the three-dimensional nature of core-collapse supernovae (CCSNe), simulations in spherical symmetry (1D) play an important role to study large model sets for the progenitor-remnant connection, explosion properties, remnant masses, and CCSN nucleosynthesis. To trigger explosions in 1D, various numerical recipes have been applied, mostly with gross simplifications of the complex microphysics governing stellar core collapse, the formation of the compact remnant, and the mechanism of the explosion. Here we investigate the two most popular treatments, piston-driven and thermal-bomb explosions, in comparison to 1D explosions powered by a parametric neutrino engine in the P-HOTB code. For this comparison we calculate CCSNe for eight stars and evolution times up to 10,000 s, targeting the same progenitor-specific explosion energies as obtained by the neutrino-engine results. Otherwise we employ widely-used ("classic") modelling assumptions, and alternatively to the standard contraction-expansion trajectory for pistons, we also test suitably selected Lagrangian mass shells adopted from the neutrino-driven explosions as "special trajectories." Although the 56Ni production agrees within roughly a factor of two between the different explosion triggers, neither piston nor thermal bombs can reproduce the correlation of 56Ni yields and explosion energies found in neutrino-driven explosions. This shortcoming as well as the problem of massive fallback witnessed in classical piston models, which diminishes or extinguishes the ejected nickel, can be largely cured by the special trajectories. These and the choice of the explosion energies, however, make the modelling dependent on pre-existing neutrino-driven explosion results.

    ↳ astro-ph.HEhep-phnucl-thMNRAS(2025)·15 citations
17. 17*

    The neutrino luminosity and energy spectrum of nova outburst

    Hao Wang🇨🇳 · Chunhua Zhu🇨🇳 · Guoliang Lü🇨🇳 · Lin Li🇨🇳 · Helei Liu🇨🇳 · Sufen Guo🇨🇳 · Xizhen Lu🇨🇳

    The nova outburst can produce a large number of neutrinos, whether it is the nuclear reaction process during the explosion or the shock wave acceleration proton process. We study the low-energy nuclear and thermal neutrino luminosity of novae with CO white dwarf (WD) mass ranging from 0.6 to 1.1 ${\mathrm{M}}_{\odot }$ with different accretion rates $\dot{M}$, core temperatures $(T_{\mathrm{C}})$, and mixing degrees. We find that during the accretion phase, low-energy neutrinos are mainly produced by pp chains and plasma decay, and photon luminosity is greater than low-energy nuclear and thermal neutrino luminosity. During the thermonuclear runaway (TNR) phase, low-energy neutrinos are mainly produced by the CNO cycle and photon-neutrino, and the low-energy nuclear and thermal neutrino luminosity far exceeds the photon luminosity. We find that the more massive the WD, the shorter the cycle time and the higher the low-energy nuclear neutrino luminosity. The higher the accretion rate, the lower the low-energy nuclear neutrino luminosity. If the accretion mixing effect is not taken into account, the outburst interval becomes longer, the low-energy nuclear neutrino luminosity will be increased. And for the cooler nova model $(T_{\mathrm{C}}=1\times 10^7\mathrm{K})$, the low-energy nuclear neutrino luminosity will be lower during the accretion phase and higher at the TNR. We also predict the neutrino luminosity and energy spectrum of the upcoming recurrent nova T Coronae Borealis (T CrB). We estimate that the next T CrB outburst has a low-energy nuclear neutrino peak luminosity of $2.7\times 10^8{\mathrm{L}}_{\nu ,\odot }$ and a low-energy nuclear neutrino outburst duration of 88 days. In addition, we predict that the high-energy hadronic neutrino flux produced by T CrB nova can not be observed by the current-generation IceCube.

    ↳ astro-ph.SRastro-ph.HEhep-phPRD(2025)·4 citations
18. 18*

    A proposal for removing $\pi N$-state contamination from the nucleon induced pseudoscalar form factor in lattice QCD

    Shoichi Sasaki🇯🇵 · Yasumichi Aoki🇯🇵 · Ken-Ichi Ishikawa🇯🇵 · Yoshinobu Kuramashi🇯🇵 · Kohei Sato🇯🇵 · Eigo Shintani🇯🇵 · Ryutaro Tsuji🇯🇵 · Hiromasa Watanabe🇯🇵 · Takeshi Yamazaki🇯🇵

    In the PACS10 project, the PACS collaboration has generated three sets of the PACS10 gauge configurations at the physical point with lattice volume larger than $(10\mathrm{fm}{)}^4$ and three different lattice spacings. The isovector nucleon form factors had been already calculated by using two sets of the PACS10 gauge configurations. In our strategy, the smearing parameters of the nucleon interpolation operator were highly optimized to eliminate as much as possible the contribution of excited states in the nucleon two-point function. This strategy was quite successful in calculations of the electric ($G_E$), magnetic ($G_M$) and axial-vector ($F_A$) form factors, while the induced pseudoscalar ($F_P$) and pseudoscalar ($G_P$) form factors remained strongly affected by residual contamination of $\pi N$-state contribution. In this work, we propose a simple method to remove the $\pi N$-state contamination from the $F_P$ form factor, and then evaluate the induced pseudoscalar charge $g_P^{\ast }$ and the pion-nucleon coupling $g_{\pi NN}$ from existing data in a new analysis. Applying this method to the $G_P$ form factor is also considered with a help of the axial Ward-Takahashi identity.

    ↳ hep-lathep-phPoS(2025)·3 citations
19. 19*

    Towards a parameter-free analysis of the QCD chiral phase transition and its universal critical behavior

    Sabarnya Mitra🇩🇪 · Frithjof Karsch🇩🇪

    To quantify the universal properties of chiral phase transition in (2+1)-flavor QCD, we use an improved, renormalized order parameter for the chiral symmetry breaking. We construct ratios of this divergence-free order parameter from its values for different pairs of light quark masses. From this, we determine in a parameter-independent manner, the chiral phase transition temperature $T_c$ and the associated critical exponent $\delta$ of the universality class. We present first numerical results of these calculations on $N_{\tau }=8$ lattices, with staggered fermions.

    ↳ hep-lathep-phnucl-exnucl-thSpringer Proc.Phys.(2026)·4 citations
20. 20*

    A Fast and Accurate Implementation of the Effective Fluid Approximation for Ultralight Axions

    Adam Moss🇬🇧 · Lauren Gaughan🇬🇧 · Anne M. Green🇬🇧

    We present a numerically efficient and accurate implementation of the Passaglia-Hu effective fluid approximation for ultralight axions (ULAs) within the Boltzmann code CAMB. This method is specifically designed to evolve the axion field accurately across cosmological timescales, mitigating the challenges associated with its rapid oscillations. Our implementation is based on the latest version of CAMB, ensuring compatibility with other cosmological codes., e.g. for calculating cosmological parameter constraints. Compared to exact solutions of the Klein-Gordon equation, our method achieves sub-percent accuracy in the CMB power spectrum across a broad range of axion masses, from $10^{-28}\mathrm{eV}$ to $10^{-24}\mathrm{eV}$. We perform Markov Chain Monte Carlo (MCMC) analyses incorporating our implementation, and find improved constraints on the axion mass and abundance compared to previous, simpler fluid-based approximations. For example, using \Planck\ PR4 and DESI BAO data, we find $2\sigma$ upper limits on the axion fraction $f_{\mathrm{ax}}<0.0082$ and physical density ${\Omega }_{\mathrm{ax}}{h}^2<0.0010$ for $m=10^{-28}$ eV. The code is publicly available at \url{https://github.com/adammoss/AxiCAMB}.

    ↳ astro-ph.COhep-phPRD(2025)·3 citations
21. 21*

    Antiquity, Dark Ages and Renaissance of Light-Front Higher Spin Theory

    Anders K H Bengtsson🇸🇪

    These notes contain -- apart from some physics -- scattered reminiscences of everyday life at the Institute for Theoretical Physics in Göteborg in the early eighties. The text has been in the making for many years. Some of it was written inspired by the Lars Brink 70-fest at The Solvay Institute in Brussels in 2014, but was never finished or published. Parts of the old text has now been replaced by a review of the quite unexpected recent renaissance for light-front higher spin theory. Lars sadly did not live to experience more than the very beginnings of this quite remarkable development. The text was finalized in the spring of 2023.

    ↳ physics.hist-phhep-phhep-thInt.J.Mod.Phys.A(2024)·0 citations
22. 22*

    A solution to the S8 tension through neutrino-dark matter interactions

    Lei Zu🇵🇱 · William Giarè🇬🇧 · Chi Zhang🇨🇳 · Eleonora Di Valentino🇬🇧 · Yue-Lin Sming Tsai🇨🇳 · Sebastian Trojanowski🇵🇱

    Neutrinos and dark matter (DM) are two of the least understood components of the Universe, yet both play crucial roles in cosmic evolution. Clues about their fundamental properties may emerge from discrepancies in cosmological measurements across different epochs of cosmic history. Possible interactions between them could leave distinctive imprints on cosmological observables, offering a rare window into dark sector physics beyond the standard $\Lambda$CDM framework. We present compelling evidence that DM-neutrino interactions can resolve the persistent structure growth parameter discrepancy, $S_8={\sigma }_8\sqrt{{\Omega }_m/0.3}$, between early and late universe observations. By incorporating cosmic shear measurements from current Weak Lensing surveys, we demonstrate that an interaction strength of $u\sim 10^{-4}$ not only provides a coherent explanation for the high-multipole observations from the Atacama Cosmology Telescope (\texttt{ACT}), but also alleviates the $S_8$ discrepancy. Combining early universe constraints with \texttt{DES Y3 cosmic shear} data yields a nearly $3\sigma$ preference for non-zero DM neutrino interactions. This strengthens previous observational claims and provides a clear path toward a significant breakthrough in cosmological research. Our findings challenge the standard $\Lambda$CDM paradigm and highlight the potential of future large-scale structure surveys, which can rigorously test this interaction and unveil the fundamental properties of DM.

    ↳ astro-ph.COastro-ph.HEhep-phNature Astron.(2026)·13 citations
23. 23*

    Free-Streaming Neutrinos and Their Phase Shift in Current and Future CMB Power Spectra

    Gabriele Montefalcone🇺🇸 · Benjamin Wallisch🇸🇪 · Katherine Freese🇺🇸

    The cosmic neutrino background and other light relics leave distinct imprints in the cosmic microwave background anisotropies through their gravitational influence. Since neutrinos decoupled from the primordial plasma about one second after the big bang, they have been free-streaming through the universe. This induced a characteristic phase shift in the acoustic peaks as a unique signature. In this work, we constrain the free-streaming nature of these relativistic species and other light relics beyond the Standard Model of particle physics by establishing two complementary template-based approaches to robustly infer the size of this phase shift from the temperature and polarization power spectra. One template shifts the multipoles in these spectra, while the other novel template more fundamentally isolates the phase shift at the level of the underlying photon-baryon perturbations. Applying these methods to Planck data, we detect the neutrino-induced phase shift at about $10\sigma$ significance, which rises to roughly $14\sigma$ with additional data from the Atacama Cosmology Telescope and the South Pole Telescope. We also infer that the data is consistent with the Standard Model prediction of three free-streaming neutrinos. In addition, we forecast the capabilities of future experiments which will enable significantly more precise phase-shift measurements, with the Simons Observatory and CMB-S4 reducing the $1\sigma$ uncertainties to roughly 4.3% and 2.5%, respectively. More generally, we establish a new analysis pipeline for the phase shift induced by neutrinos and other free-streaming dark radiation which additionally offers new avenues for exploring physics beyond the Standard Model in a signature-driven and model-agnostic way.

    ↳ astro-ph.COhep-phhep-thJCAP(2025)·19 citations
24. 24*

    Inflaton Self Resonance, Oscillons, and Gravitational Waves in Small Field Polynomial Inflation

    Manuel Drees🇩🇪 · Chenhuan Wang🇩🇪

    In this work, we investigate the post-inflationary dynamics of a simple single-field model with a renormalizable inflaton potential featuring a near-inflection point at a field value ${\varphi }_0$. Due to the concave shape of the scalar potential, the effective mass of the inflaton becomes imaginary during as well as for some period after slow-roll inflation. As a result, in the initial reheating phase, where the inflaton oscillates around its minimum with a large amplitude, some field fluctuations grow exponentially; this effect becomes stronger at smaller ${\varphi }_0$. This aspect can be analyzed using the Floquet theorem. We also analytically estimate the backreaction time after which the perturbations affect the evolution of the average inflaton field. In order to fully analyze this non-perturbative regime, we perform a (classical) lattice simulation, which reveals that the exponential growth of field fluctuations can fragment the system. This leads to a large amount of non-Gaussianity at very small scales, but the equation of state remains close to matter-like. The evolution of the background field throughout the fragmentation phase can be understood using the Hartree approximation. For sufficiently small ${\varphi }_0$ soliton-like objects, called oscillons in the literature, are formed. This leads to areas with high local over-density, $\delta \rho \gg \bar{\rho }$ where $\bar{\rho }$ is the average energy density. We speculate that this could lead to the formation of light primordial black holes, with lifetime $\gtrsim 10^{-19}\text{sec}$. Other possibly observational consequences, in particular gravitational waves in the $\text{MHz}-\text{GHz}$ range, are discussed as well. Although a complete analytical study is difficult in our case, we obtain a power law scaling for the potential observables on ${\varphi }_0$.

    ↳ astro-ph.COhep-phJCAP(2025)·13 citations
25. 25*

    Redshift leverage for the search of GRB neutrinos affected by quantum properties of spacetime

    Giovanni Amelino-Camelia🇮🇹 · Giacomo D'Amico🇳🇴 · Vittorio D'Esposito🇮🇹 · Giuseppe Fabiano🇺🇸 · Domenico Frattulillo🇮🇹 · Giulia Gubitosi🇮🇹 · Dafne Guetta🇮🇱 · Alessandro Moia🇮🇹 · Giacomo Rosati🇮🇹

    Some previous studies based on IceCube neutrinos had found intriguing preliminary evidence that some of them might be GRB neutrinos with travel times affected by quantum properties of spacetime delaying them proportionally to their energy, an effect often labeled as "quantum-spacetime-induced in-vacuo dispersion". Those previous studies looked for candidate GRB neutrinos in a fixed (neutrino-energy-independent) time window after the GRB onset and relied rather crucially on crude estimates of the redshift of GRBs whose redshift has not been measured. We here introduce a complementary approach to the search of quantum-spacetime-affected GRB neutrinos which restricts the analysis to GRBs of sharply known redshift, and, in a way that we argue is synergistic with having sharp information on redshift, adopts a neutrino-energy-dependent time window. We find that knowing the redshift of the GRBs strengthens the analysis enough to compensate for the fact that of course the restriction to GRBs of known redshift reduces the number of candidate GRB neutrinos. And rather remarkably our estimate of the magnitude of the in-vacuo-dispersion effects is fully consistent with what had been found using the previous approach. Our findings are still inconclusive, since their significance is quantified by a $p$-value of little less than $0.01$, but provide motivation for monitoring the accrual of neutrino observations by IceCube and KM3NeT as well as for further refinements of the strategy of analysis here proposed.

    ↳ gr-qcastro-ph.HEhep-phJCAP(2026)·4 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.