Fri·Feb 27, 2026Friday·February 27, 2026

1. 01*

   Fluctuation-Dissipation Relation for Hard Partons in a Gluonic Plasma

   Amit Kumar🇨🇦 · Abhijit Majumder🇺🇸 · Ismail Soudi🇩🇪 · Johannes Heinrich Weber🇩🇪

   We derive a fluctuation dissipation relation connecting the drag and diffusion jet transport coefficients for an energetic light quark traversing a non-perturbative thermalized gluon plasma. The hard quark is taken to be close to on-shell, with an energy scale parametrically larger than the medium temperature. We introduce a general complex-valued function for each transport coefficient. Evaluating these in the deep Euclidean momentum region enables their expression in terms of local operators. Using contour-integration techniques, we relate these local operators, after vacuum subtraction, to the physical transport coefficients that arise along a branch cut, close to light-like dispersion. The derived relation relates the longitudinal drag coefficient to the longitudinal and transverse diffusion coefficients, and the thermal gluon condensate.

   hep-phhep-latnucl-th0 citations
2. 02*

   Flavorful Lepton Number Violation at the EIC

   Sebastián Urrutia Quiroga🇺🇸 · Vincenzo Cirigliano🇺🇸 · Wouter Dekens🇺🇸 · Kaori Fuyuto🇯🇵 · Emanuele Mereghetti🇺🇸

   We explore the prospects of detecting flavorful lepton number violation at the Electron-Ion Collider (EIC) through resonant production of heavy neutral leptons (HNLs), resulting in $e^{-}p\to {\ell }_{\alpha }^{+}+kj+X$, where $\alpha \in \{e,\mu ,\tau \}$ and $k$ denotes the number of jets. We work in the $\nu$SMEFT framework of the Standard Model Effective Field Theory augmented with $n$ singlet HNLs, one of which is in the mass range $10-100$~GeV, within kinematic reach of the EIC. To explore the EIC sensitivity, we focus on the HNL production mechanism induced by mixing with light neutrinos. We study kinematic distributions for signal and backgrounds, including hadronization and detector effects, and suggest a set of cuts to minimize backgrounds. In the mass range considered, we find that the EIC with muon detection capabilities and an integrated luminosity of $100{\mathrm{fb}}^{-1}$ can reach sensitivities comparable to the strongest direct (LHC) and indirect constraints, and is especially relevant in the $\nu$SMEFT framework beyond dimension four. Our study motivates further assessment of muon detection capabilities at the EIC and $\tau$ hadronic reconstruction, as well as a more general theoretical analysis involving production mechanisms mediated by higher-dimensional operators in the effective theory.

   hep-phhep-exnucl-exnucl-th1 citation
3. 03*

   Current-carrying string network evolution in an external magnetic field

   P. B. Barbosa🇵🇹 · C. J. A. P. Martins🇵🇹

   Cosmic strings are topological defects arising in a variety of cosmological scenarios, as the Universe undergoes symmetry-breaking phase transitions, whose discovery would offer valuable insight into the high-energy physics that shaped the early Universe. To interpret such a detection, robust theoretical models are essential. The Velocity-dependent One-Scale (VOS) model is particularly prominent: it self-consistently treats the network as a thermodynamic system, characterizing its key properties, and predicting its large-scale evolution. This has recently been extended to include superconducting cosmic strings, which carry additional degrees of freedom, giving rise to the Charge-Velocity dependent One-Scale (CVOS) model. One limitation of the latter model is that it only included loss mechanisms for the charge and current. Here, we extend this model by phenomenologically including a possible energy source mechanism, specifically by allowing current-carrying strings interactions with an external magnetic field. We discuss how this coupling impacts the network's evolution, present and classify the physically allowed scaling solutions for this extended CVOS model, and comment on the different impacts of the external magnetic field on the evolution of the network's charge and current. Under our modeling assumptions, one of the ten physically plausible scaling solution enables the network to gain energy by this mechanism.

   hep-phastro-ph.COPRD(2026)·0 citations
4. 04*

   Effects of dispersion parity-violating interaction in electron scattering and atoms

   V. V. Flambaum🇦🇺 · I. B. Samsonov🇦🇺

   Exchange of two neutrinos (as well as other fermions) generates a long-range parity-violating potential of the form $\sim G^2/r^5$, with characteristic range $\hslash /(2m_{\nu }c)$. In atomic systems the corresponding matrix elements converge at distances $r<10/M_Z$, so that the interaction between electron and quarks effectively reduces to a contact term $\sim G^2{M}_Z^2{\delta }^3(\vec{r})\sim G\alpha {\delta }^3(\vec{r})$. This interaction produces a $-0.8\%$ correction to the effective weak charge of cesium, resolving the $2\sigma$ discrepancy between the Standard Model prediction and the measured Cs parity-violation amplitude. The corresponding value of the weak mixing angle is ${\sin }^2{\theta }_W=0.2375(19)$ at $q^2\approx 0$, in agreement with the Standard Model prediction ${\sin }^2{\theta }_W=0.23873$. The relative correction to the proton weak charge is about $3\%$. Using these results, we revisit the limits on an additional $Z^{\prime }$ boson and obtain a constraint on isospin-conserving oblique radiative corrections characterized by the Peskin--Takeuchi parameter $S=-0.32(53)$ at $q^2\approx 0$.

   hep-phphysics.atom-phPRD(2026)·7 citations
5. 05*

   ACT-Consistent B-L Higgs Inflation in Supergravity

   C. Pallis🇬🇷

   We consider a renormalizable extension of the minimal supersymmetric standard model (MSSM) endowed by an R and a gauged B - L symmetry. The model incorporates chaotic inflation driven by a quartic potential, associated with the Higgs superfields which lead to a spontaneous breaking of U(1)B-L. Consistency with the ACT data is achieved by considering a fractional shift-symmetric Kaehler potential which includes two free parameters (p,N) constrained in the ranges 1.355<p<6.7 and 6x10^-5<N<0.7. An explanation of the mu term of the MSSM is also provided, under the condition that a related parameter in the superpotential is somewhat small. Baryogenesis occurs via non-thermal leptogenesis which is also realized by the inflaton's decay to the lightest and/or next-to-lightest right-handed neutrinos for normal ordered light neutrino masses.

   hep-phastro-ph.COhep-thPoS(2026)·3 citations
6. 06*

   Charmed nuclei and exotic charmed meson production at CBM@FAIR and ALICE@LHC

   Thanaporn Chimruang🇹🇭 · Christoph Herold🇹🇭 · Ayut Limphirat🇹🇭 · Yupeng Yan🇹🇭 · Jan Steinheimer🇩🇪 · Benjamin Dönigus🇩🇪 · Tom Reichert🇨🇭 · Volodymyr Vovchenko🇺🇸 · Marcus Bleicher🇩🇪

   We make predictions for the expected multiplicities of exotic charmed hadrons and charmed nuclei in Au+Au collisions at SIS100 and LHC beam energies, using input on light hadron and charm production from the UrQMD transport model, and applying the Thermal-FIST model. We demonstrate that the CBM experiment has the capability to explore these states with production rates of one per 3 seconds for ${\chi }_{c0}(1P)$ and ${\chi }_{c1}(1P)$, and one every 3 minutes for $X(3872)$ at the expected data taking rates. Due to the higher baryon density at CBM compared to the LHC, charmed nuclei, if they exist, will be equally abundant at CBM as at the LHC, even though the total charm production at CBM is much lower.

   hep-phhep-thPLB(2026)·2 citations
7. 07*

   Weak dual symmetries of two color QCD phase diagram

   K. G. Klimenko🇷🇺 · R. N. Zhokhov🇷🇺

   The phase diagram of two color QCD under influence of baryon density (${\mu }_B$), isospin (${\mu }_I$), chiral (${\mu }_5$ and ${\nu }_5$) imbalances is investigated within the framework NJL model approach. This letter establishes the existence of weak dualities in two color quark matter--symmetries revealed when full thermodynamic potential is projected or restricted to specific condensation channels. These dualities provide a unified understanding of two interesting phenomena in the phase diagram: universal catalysis and chameleon effect of chiral chemical potential.

   hep-phMoscow Univ.Phys.Bull.(2025)·0 citations
8. 08*

   Testing beyond the Standard Model scenarios in next-generation long-baseline neutrino oscillation experiments

   Pragyanprasu Swain🇮🇳

   In this thesis, we assess the sensitivity of next-generation long-baseline neutrino oscillation experiments, DUNE, T2HK, and T2HKK, to three popular beyond the Standard Model (BSM) scenarios. Within the three BSM studies, we examine: (i) long-range neutrino-matter interactions induced by flavor-dependent, anomaly-free gauged baryon-lepton symmetries mediated by ultra-light vector boson, showing that DUNE and T2HK can constrain, discover, and in some favorable cases distinguish among different symmetries; (ii) Lorentz invariance violation (LIV), where we derive analytical dependencies of CPT-conserving and CPT-violating LIV parameters on baseline and energy, highlighting the superior reach of DUNE in probing all the LIV parameters, in contrast to T2HK, which is essentially blind to the CPT-conserving LIV parameters; and (iii) active-sterile oscillations over a broad range of $\Delta m_{41}^2$, where we derive sensitivity to CP phases for benchmark choices of $\Delta m_{41}^2$ and establish exclusion limits, emphasizing the role of near detectors. Together, these studies show that future long-baseline facilities not only resolve the neutrino mass ordering, value of ${\delta }_{\mathrm{CP}}$, and ${\theta }_{23}$ octant, but also provide powerful probes of BSM physics.

   hep-phhep-exphysics.ins-det0 citations
9. 09*

   Bottom-charmed meson states in inverse problem of QCD

   Halil Mutuk🇹🇷 · Duygu Yıldırım🇹🇷

   We present a comprehensive analysis of the bottom-charmed ($B_c$) meson spectrum within the inverse matrix QCD sum rules formalism. In this framework, conventional QCD sum rules are recast as an inverse problem, allowing for the direct reconstruction of hadronic spectral densities from first principles without invoking phenomenological continuum parametrizations or quark-hadron duality assumptions. We compute the masses and decay constants of conventional $B_c$ mesons with quantum numbers $J^P=0^{-}$, $1^{-}$, $0^{+}$, and $1^{+}$. The obtained results are in close agreement with available experimental measurements and are consistent with predictions from various theoretical and phenomenological approaches. The inverse matrix formulation exhibits improved numerical stability and reduced systematic uncertainties relative to standard implementations, highlighting its suitability for precision spectroscopy of heavy quarkonium systems.

   hep-phhep-exhep-latEPJC(2026)·0 citations
10. 10*

    Isospin symmetry breaking and the mass of the QCD axion in a three-flavor linear sigma model

    András Patkós🇭🇺

    The topology of the ground state of QCD manifests itself through the dependence of its potential energy density on the CP-violating angle $\Theta$. This is computed in the present note within a three-flavor linear meson model. It is shown that the isospin symmetry breaking condensate leads to a 5\% shift in the scale of topological fluctuations, due to which a value emerges in close agreement with lattice QCD determinations. Transparent analytical computation makes explicit the physical content of each step significantly correcting the starting crude estimate of topological susceptibility and eventually achieving the quite accurate final result. This clear physical interpretation lends also a certain pedagogical value to the proposed treatment.

    hep-phMod.Phys.Lett.A(2026)·0 citations
11. 11*

    NNLO QCD corrections to hadron production in DIS at finite transverse momentum

    Liang Dong🇨🇳 · Shen Fang🇨🇳 · Jun Gao🇨🇳 · Hai Tao Li🇨🇳 · Ding Yu Shao🇨🇳 · Yu Jiao Zhu🇩🇪

    We present the first complete calculation of hadron production in deep-inelastic scattering (DIS) at finite transverse momentum to next-to-next-to-leading order (NNLO) in perturbative QCD. To overcome the long-standing challenge of infrared divergences in semi-inclusive processes with identified final state hadrons at finite transverse momentum, we implement the recently developed $q_T$-subtraction framework based on the recoil-free jet definition. By utilizing the winner-take-all recombination scheme, we achieve a consistent factorization for hadron-jet associated production, enabling the inclusion of $\mathcal{O}({\alpha }_s^3)$ corrections. Our results demonstrate a significantly improved stabilization of the perturbative expansion and a reduction in scale uncertainties compared to previous next-to-leading order predictions. We find that the NNLO corrections are essential for a robust description of high precision multiplicity data from the ZEUS collaborations. This work provides a high precision theoretical foundation for the upcoming Electron-Ion Collider era and establishes a new benchmark for the exploration of the nucleon's three-dimensional structure.

    hep-phhep-exPRL(2026)·2 citations
12. 12*

    A Predictive Non-Holomorphic Modular $A_4$ Linear Seesaw Framework Testable at DUNE

    Rudra Majhi🇮🇳 · Mitesh Kumar Behera🇮🇳 · Rukmani Mohanta🇮🇳

    We study a realization of neutrino masses and mixing phenomena within a linear seesaw mechanism based on non-holomorphic modular $A_4$ symmetry, which extends modular-invariant flavor models beyond the conventional holomorphic framework. The model is constructed in a non-supersymmetric setting and involves six heavy $SU(2{)}_L$ singlet fermions, $N_{Ri}$ and $S_{Li}$, together with a single flavon field, thereby significantly reducing the field content compared to conventional $A_4$ flavor models that typically require multiple flavon fields as well as supersymmetric (holomorphic) modular frameworks involving additional superfields. The modular transformation properties of the Yukawa couplings under $A_4$ symmetry lead to a highly constrained neutrino mass matrix with a distinctive flavor structure. After presenting the general theoretical framework, we perform a systematic numerical analysis of neutrino phenomenology by restricting the modulus parameter $\tau$ to the fundamental domain and scanning the allowed parameter space. We identify regions consistent with current neutrino oscillation data at the $3\sigma$ level and obtain predictions for currently unknown observables, including the absolute neutrino mass scale and leptonic CP-violating phases. We further examine the implications for neutrinoless double beta decay, highlighting testable signatures in the upcoming precision oscillation as well as rare-process experiments. These results demonstrate the phenomenological viability and predictive power of non-holomorphic modular symmetry in linear seesaw neutrino mass models.

    hep-phJHEP(2026)·6 citations
13. 13*

    Ruling Out Spiky WIMP Dark Matter using Indirect Searches

    Dibya S. Chattopadhyay🇺🇸 · P. S. Bhupal Dev🇺🇸 · Yago Porto🇩🇪

    The dark matter (DM) density profile in the innermost region of the Galaxy remains an open question. In particular, while adiabatic growth of the supermassive black hole Sgr A${}^{\ast }$ at the Galactic Center (GC) can induce a 'spike' in central DM density, the existence of such a spike is still under debate. Here we present new constraints on the spike slope ${\gamma }_{\mathrm{sp}}$ using conventional DM indirect detection searches. We first recast existing photon and neutrino line searches, which include the contribution from the GC region, into constraints on the thermally-averaged DM annihilation cross section $⟨\sigma v⟩$ in the presence of a DM spike. We then derive new bounds on the spike profile for a generic Weakly Interacting Massive Particle (WIMP) DM scenario, where the thermal freeze-out mechanism fixes the annihilation cross-section at $⟨\sigma v⟩\sim (2-3)\times 10^{-26}{\mathrm{cm}}^3{\mathrm{s}}^{-1}$. We find that, for DM annihilation to photons, existing \emph{Fermi}-LAT and MAGIC data place strong constraints on spike profiles at the GC over a broad range of WIMP DM masses, from 10 GeV to 100 TeV, for photon branching fractions down to $\sim 10^{-2}$, and remain sensitive to values as small as $\sim 10^{-4}$ in parts of the parameter space. For the neutrino channel, we use the recent IceCube data to constrain the existence of an extremely steep spike in the $\mathcal{O}(1-10)$~TeV DM mass range. Our analysis can be easily extended to other annihilation channels.

    hep-phastro-ph.GAJCAP(2026)·4 citations
14. 14*

    Black hole scalar sirens in the Milky Way

    Daniel Gavilan-Martin🇩🇪 · Olivier Simon🇺🇸 · Dhashin Krishna🇩🇪 · Derek F. Jackson Kimball🇺🇸 · Dmitry Budker🇩🇪 · Arne Wickenbrock🇩🇪

    Hypothetical light scalar particles trigger the superradiant instability around spinning black holes (BHs), causing clouds of scalars to grow around the BH. In the presence of sufficiently strong particle self-interactions (characterized by the decay constant $f$), scalars are ejected from BH orbits, resulting in coherent, non-relativistic emissions that continuously carry away the BH's angular momentum. Parameters exist for which cloud growth is much faster, and scalar depletion is much slower, than the age of the Galaxy. This defines a distinct class of astrophysical sources of scalars, which we call BH scalar sirens -- BHs that persistently emit scalars effectively forever. We compute the scalar background from the expected population of $N_{\text{BH}}\sim 10^8$ isolated stellar-mass BHs in the Milky Way, which are sirens for scalars in the mass range $10^{-13}$--$10^{-11}$eV and $f\lesssim 10^{14}$--$10^9$GeV. This provides a detection target independent of early-universe scalar production or cosmological initial conditions. The generated observable signals are up to two orders-of-magnitude larger than those expected from a misaligned cosmic scalar in this mass range. The energy spectrum of emitted scalars is distinctly broader and at higher velocities (up to $\sim 10^{-1}c$) than that of virialized dark matter, and encodes the mass and spin distributions of the BH population. While stellar-mass Milky Way BHs are our primary target, our framework extends to supermassive, intermediate-mass and light BHs. Given the difficulty of directly observing populations of isolated BHs, scalar emissions offer a novel probe of these otherwise invisible objects, highlighting the potential for joint discovery between scalars and BHs, and broadly motivating searches for scalars over many orders-of-magnitude in mass.

    hep-phastro-ph.HEhep-exphysics.atom-ph6 citations
15. 15*

    Neutrino NSI in archaeological Pb

    D. Alloni🇮🇹 · G. Benato🇮🇹 · P. Carniti🇮🇹 · M. Cataldo🇮🇹 · D. Cerdeño🇪🇸 · A. Cheek🇨🇳 · L. Cheng🇨🇳 · M. Clemenza🇮🇹 · M. Consonni🇮🇹 · G. Croci🇮🇹 · I. Dafinei🇮🇹 · F.A. Danevich🇺🇦 and 38 other authors

    Dark matter direct detection experiments can observe solar neutrinos via coherent elastic neutrino-nucleus scattering, making it possible to test new physics in the neutrino sector. In this article, we study the sensitivity of RES-NOVA, a novel cryogenic calorimetric experiment employing PbWO${}_4$ crystals grown from archaeological lead, to neutrino non-standard interactions (NSI). We perform a sensitivity study for a benchmark setup with a nominal energy threshold of 1 keV and an exposure of 1 ton$\cdot$y, both for a conservative (only heat readout) and ideal (heat and scintillation) background rejection scenario. We find that, in its nominal configuration, while not being sensitive to Standard Model solar $\nu$ interactions, RES-NOVA can reach sensitivities to NSI at the level of current global fits. With moderate or significant improvements of the threshold down to $0.5$ keV and $0.2$ keV, RES-NOVA will be able to achieve sensitivities beyond NSI global fit results, testing new areas of the parameter space in the electron and tau sectors, ${\epsilon }_{ee}$, ${\epsilon }_{\tau \tau }$, and ${\epsilon }_{e\tau }$. A similar improvement in sensitivities is expected when instead increasing the exposure to 10 ton$\cdot$y.

    hep-phJHEP(2026)·3 citations
16. 16*

    Axiverse Lampposts

    Masha Baryakhtar🇺🇸 · David Cyncynates🇺🇸 · Ella Henry🇺🇸

    The string axiverse predicts a unique connection between the high scales approachable only through theory and the low energies within reach of experimental verification: a multitude of light, feebly interacting axions. In order to capture the collective effects of such an axion ensemble, we model the string axiverse by $N$ coupled axions with a simple assumption: hierarchical axion masses that arise from hierarchical instantons with statistically distributed axion couplings. In this limit, we find that axion field ranges, which determine late-time cosmological abundances, shrink as $1/\sqrt{N}$ as the number of axions grows. Moreover, the heaviest modes tend to align with the smallest kinetic eigenvalues, further reducing their field ranges. Interactions with the Standard Model (SM) are largely set by the kinetic structure and do not grow with $N$, thus suppressing detection prospects relative to the individual-axion expectation. The main exception is the QCD axion, whose coupling is tied to its potential and is therefore unsuppressed. The heaviest and lightest axions can also avoid the typical suppression in certain limits. We further find that coupled axiverse dark matter has parametrically relaxed tuning on initial conditions when produced via long, low-scale inflation relative to independent axions and high-scale inflation. Taken together, these results sharpen the observational outlook: the most accessible signals typically come from the QCD axion and from heavy axions that make up small dark matter subcomponents. An anthropic plateau of comparable energy density states produces subdominant signals; meanwhile, if light axions have SM interactions independent of QCD, they can also be within reach of future direct-detection experiments.

    hep-phhep-th10 citations
17. 17*

    Extracting a Toponium Signal at the LHC with Spin and Quantum Information Tools

    Laura Antozzi🇮🇹 · Esteban Chalbaud🇵🇹 · Frédéric Déliot🇫🇷 · Federica Fabbri🇮🇹 · Miguel C.N. Fiolhais🇵🇹 · Benjamin Fuks🇫🇷 · António Onofre🇵🇹 · Martin White🇦🇺 · Pengxuan Zhu🇦🇺

    We investigate near-threshold top-antitop production at the LHC, focusing on the impact of toponium formation on spin correlations and quantum information properties of the final state. Considering the top-antitop system as a mixed two-qubit state, we reconstruct spin density matrices via quantum tomography and evaluate several observables including some inspired by quantum information. We then compare their sensitivity in discriminating toponium effects from top-antitop production without these effects. Our results demonstrate that combining these variables is expected to significantly enhance sensitivity to toponium effects, bringing new ways to explore these subtle features.

    hep-phhep-exJHEP(2026)·8 citations
18. 18*

    Fluctuations in atom interferometers as a new tool for dark matter

    Clara Murgui🇨🇭 · Ryan Plestid🇨🇭

    We propose the use of the super-binomial variance in the count rate of an atom interferometer as a novel signature of dark matter. We show that the dark matter induced shift in this observable is enhanced by N, the number of atoms used per run of the interferometer, and therefore offers sensitivity that is enhanced by orders of magnitude relative to an independent-atom estimate. As an application, we consider dark matter that interacts with electrons, protons, and/or neutrons, via a long-range Yukawa interaction and new constraints on strongly interacting dark matter that thermalizes in the overburden of conventional direct detection experiments. We find that searches for super-binomial variance extend, and complement, existing atom interferometer observables; they are well suited to search for both short- and long-ranged forces.

    hep-ph0 citations
19. 19*

    AGN Feedback and the Development of Dusty Multiphase Gas in X-ray Emitting Elliptical Galaxies

    Pasquale Temi · Francesco Ubertosi · Fabrizio Brighenti · Alexandros Maragkoudakis · Valeria Olivares · Alexandre Amblard · Massimo Gaspari · Myriam Gitti · Pamela M. Marcum · Kevin Fogarty · Alejandro S. Borlaff · William G. Mathews

    This paper investigates the physical and kinematic properties of dust-rich regions in a small sample of group-centered elliptical galaxies, emphasizing their connection with the hot X-ray emitting gas and detailed dust grain characteristics. Comprehensive multi-wavelength data, including H-alpha and CO emission detected by MUSE and ALMA, demonstrate the presence of dust clouds embedded within complex, hot X-ray atmospheres shaped by AGN feedback. X-ray images show bubbles and cavities surrounded by bright rims. We find that dust regions containing molecular gas traced by CO are preferentially located at the rims of these X-ray cavities, suggesting that AGN-driven outflows enhance the condensation of cold, dusty gas at these compressive interfaces. Kinematic measurements indicate that molecular and ionized gas phases are dynamically and spatially linked, supporting the framework of a multiphase medium arising from the top-down condensation rain in the hot plasma and related chaotic cold accretion. Crucially, spatial variations in the total-to-selective extinction ratio Rv show that regions where dust, CO, and H-alpha emission coincide exhibit notably smaller Rv values, implying steeper extinction curves and the predominance of smaller or less evolved dust grains within these mixed-phase environments. This contrasts with larger Rv values found elsewhere in the dust clouds, suggesting grain growth or survival mechanisms within shielded cold gas.

    ↳ astro-ph.GAhep-phApJ(2026)·2 citations
20. 20*

    The shape of transverse momentum spectra in hybrid hydrodynamic models

    Thiago S. Domingues🇧🇷 · Fernando G. Gardim🇧🇷 · Cicero D. Muncinelli🇧🇷 · Andre V. Giannini🇵🇹 · Gabriel S. Denicol🇧🇷 · Tiago Nunes da Silva🇧🇷 · David D. Chinellato🇦🇹 · Giorgio Torrieri🇧🇷 · Mauricio Hippert🇧🇷 · Jun Takahashi🇧🇷 · Matthew Luzum🇧🇷

    We study the scaled transverse momentum spectra over a wide parameter space of state-of-the-art hydrodynamic simulation models in order to learn what information can be obtained from the shape of identified-particle spectra -- previously observed to be surprisingly universal across centrality and collision systems in both experimental data and hydrodynamic simulations. We study its sensitivity to each of 17 model parameters in the context of 4 different models for particlization when switching from the hydro description to the kinetic theory afterburner. We find that the strongest sensitivity is to parameters relating to bulk viscosity, free-streaming time, and the \texttt{T_\mathrm{R}ENTo} nucleon width parameter $w$. However, we find that the model generally has surprisingly little flexibility in describing the scaled spectrum observable, despite the large number of parameters. Within this small range of parameter dependence, we further find significant tension in a simultaneous description of momentum-integrated observables. In particular, while the mean transverse momentum prefers a large value of the nucleon width parameter $w$, a small value is required to obtain scaled spectra that are consistent with experimental measurements. We speculate on the origin of these model tensions and possible missing physics in the commonly-used \texttt{T_\mathrm{R}ENTo}+free streaming+hydro+afterburner simulation model.

    ↳ nucl-thhep-phhep-th2 citations
21. 21*

    Statistical properties of non-flow correlations in pp and heavy-ion collisions at RHIC energies

    Satya Ranjan Nayak🇮🇳 · Akash Das🇮🇳 · B.K. Singh🇮🇳

    In this work, we have studied the two-particle cumulant in pp, d-Au, and Au-Au collisions. The two-particle cumulant was treated as an event-by-event distribution, and its skewness and kurtosis were analyzed. The non-flow correlations, like jets and decays, constantly produced a skewed distribution, regardless of the model used. On the contrary, HYDJET++ produced a smooth Gaussian distribution at higher $\eta$ windows in fixed impact parameter collisions. The skewness increased consistently for higher $\eta$ windows in all non-QGP models like PYTHIA, PHOJET, QGSJET, and DPMJET. The kurtosis of the distribution also increased with $\eta$ windows in non-QGP models. The skewness and kurtosis of the distributions produced by HYDJET++ decreased with $\Delta \eta$ and eventually reached zero at higher $\Delta \eta$.

    ↳ nucl-thhep-ph0 citations
22. 22*

    Space-time regions of high baryon density and baryon stopping in heavy-ion collisions

    Yuri B. Ivanov🇷🇺

    Four-volumes ($V_4=$ spatial-3-volume$\times$lifetime) are calculated within the model of three-fluid dynamics (3FD) and compared with those of the the JET AA Microscopic Transport Model (JAM). The calculations are performed for central Au+Au collisions at energies $\sqrt{s_{NN}}=$ 3 -- 19.6 GeV. These $V_4$ indicate optimal collision-energy ranges for realizing macroscopic high baryon-density matter. It is found that the 3FD four-volumes noticeably exceed those in the JAM, which indicates a stronger baryon stopping in the 3FD model as compared to that JAM. It is argued that this difference in the baryon stopping correlates with stiffness of the EoS implemented in these models. Contrary to JAM, the four-volume, where a baryon density ($n_B$) exceeds three times the normal nuclear density ($n_0$), does not exhibit a maximum as a function of $\sqrt{s_{NN}}$. It decreases monotonically with increasing $\sqrt{s_{NN}}$, remaining at a fairly macroscopic level (i.e. $V_4\ge 5.5^4$ fm${}^4$/c). For higher baryon densities, $V_4$ exhibits maxima in its dependence on $\sqrt{s_{NN}}$. The optimal energy range for densities $n_B/n_0>$ 4 is located at $\sqrt{s_{NN}}=$ 3.2 -- 8 GeV. Even for $n_B/n_0>$ 6, the four-volume remains quite macroscopic ($V_4\ge 4^4$ fm${}^4$/c) at $\sqrt{s_{NN}}=$ 4.5 -- 9 GeV contrary to the JAM.

    ↳ nucl-thhep-phPRC(2026)·1 citation
23. 23*

    BPS lumps in the Nonminimal $C{P}^1$ Maxwell-Chern-Simons Model

    I. B. Cunha🇧🇷 · F. C. E. Lima🇧🇷 · Aldo Vera🇨🇱

    We investigate self-dual radially symmetric configurations in the $C{P}^1$ model coupled to a Maxwell and Chern-Simons (CS) gauge fields through nonminimal interactions. Starting from the nonlinear $O(3)$-sigma model, we explicitly construct its classical mapping to the $C{P}^1$ formulation, highlighting the emergence of a local $U(1)$ gauge symmetry intrinsically associated with the Fubini-Study geometry of the target space. In the static regime, the combined effects of the Chern-Simons term and the Pauli-like nonminimal coupling modify the effective gauge connection, render the electric sector unavoidable, and give rise to magnetized and electrically polarized BPS lump configurations. By implementing the Bogomolnyi procedure, we determine the self-interaction potential required for self-duality and derive the corresponding BPS equations. We show that the magnetic flux remains quantized and is completely fixed by the asymptotic behavior of the gauge field, even in the presence of the Chern-Simons and nonminimal couplings. A detailed asymptotic analysis further reveals that finite-energy solutions necessarily correspond to lump-like configurations in which the $C{P}^1$ scalar field vanishes at spatial infinity. Numerical solutions of the BPS equations confirm that the resulting configurations are regular, spatially localized, and free of singularities, exhibiting confined magnetic flux together with a nontrivial localized electric field. These results show that the generalized $C{P}^1$-Maxwell-CS model supports self-dual solitons whose internal structure is rigidly governed by the target-space geometry rather than by spontaneous symmetry breaking.

    ↳ hep-thhep-phEPJC(2026)·3 citations
24. 24*

    Tight bounds on the Maxwell-Carroll-Field-Jackiw parameters using Fast Radio Bursts

    Filipe S. Ribeiro🇧🇷 · Pedro D. S. Silva🇧🇷 · Rodolfo Casana🇧🇷 · Manoel M. Ferreira Jr🇧🇷

    We investigate the arrival time and the Faraday rotation of extragalactic electromagnetic signals from fast radio bursts (FRBs) propagating through chiral cosmic media within the framework of Maxwell-Carroll-Field-Jackiw (MCFJ) electrodynamics. By treating the interstellar medium as a cold, ionized chiral plasma, we derive the time delay between two traveling signals, expressing it in terms of modified dispersion measures (DMs) containing chiral contributions. The Faraday rotation angle is then written in terms of modified rotation measures (RMs). By combining the DMs and redshift data from a set of FRBs, we obtain constraints on the chiral parameter magnitude at the order of $10^{-26}$--$10^{-24}$ GeV. Using the Faraday rotation formulae and RM measurements, upper bounds as stringent as $10^{-43}$ GeV on the MCFJ parameters are also obtained.

    ↳ astro-ph.HEhep-ph1 citation
25. 25*

    Confinement transition to gravitational waves in the one-flavor $SU(4)$ Hyper Stealth Dark Matter theory

    V. Ayyar🇺🇸 · R. C. Brower🇺🇸 · G. T. Fleming🇺🇸 · J. Ingoldby🇬🇧 · X. Y. Jin🇺🇸 · N. Matsumoto🇺🇸 · A. S. Meyer🇺🇸 · E. T. Neil🇺🇸 · J. C. Osborn🇺🇸 · S. Park🇺🇸 · C. T. Peterson🇺🇸 · D. Schaich🇬🇧 · P. Vranas🇺🇸 · O. Witzel (Lattice Strong Dynamics Collaboration)🇩🇪

    The thermodynamics of the $SU(4)$ gauge theory with a single flavor of fundamental quarks is analyzed on the lattice with dynamical fermion simulations, which is the low-energy sector of a realistic, strongly-interacting dark matter model -- the Hyper Stealth Dark Matter. The gravitational wave spectrum from the first-order confinement transition in the early universe is further calculated, where the effect of the dark sea quarks, which decrease the interface tension in the effective potential of the Polyakov loop, is shown numerically to lower the gravitational wave amplitude.

    ↳ hep-latastro-ph.COhep-ph3 citations
26. 26*

    Form factors of the $\rho$ meson from effective field theory and the lattice

    Ulf-G. Meißner🇩🇪 · Akaki Rusetsky🇩🇪 · Ajay S. Sakthivasan🇩🇪 · Gerrit Schierholz🇩🇪 · Jia-Jun Wu🇨🇳

    The calculation of resonance form factors in effective field theory as well as on the lattice is a highly challenging task. In a recent paper, we proposed a novel method based on the introduction of a background field and the Feynman-Hellmann theorem to address the problem, and applied it to a toy model. In the present work we use this method for the electromagnetic form factors of the $\rho$-meson. By matching the results to Chiral Perturbation Theory, we provide a first, crude estimate of all three form factors of the $\rho$-meson within the effective field theory. Contact contributions to these form factors turn out to be substantial. A procedure for lattice calculations is outlined, paving the way for an ab initio approach to the problem.

    ↳ hep-lathep-phnucl-thJHEP(2026)·7 citations
27. 27*

    Spatially inhomogeneous confinement-deconfinement phase transition in rotating QGP

    V. V. Braguta🇷🇺 · M. N. Chernodub🇫🇷 · Ya. A. Gershtein🇷🇺 · A. A. Roenko🇷🇺

    Using first-principles numerical simulations, we find a new spatially inhomogeneous phase in a rotating gluon plasma. This mixed phase simultaneously contains regions of both confining and deconfining states in thermal equilibrium, separated by a spatial transition. The position of the boundary between the two phases is determined by the local critical temperature. We calculate the critical temperature of the local transition as a function of angular velocity and radius for a full (imaginary) rotating system and within a local thermalization approximation, and find an excellent agreement between these approaches. An analytic continuation of the results to the domain of real angular frequencies indicates that the confinement phase localizes at the periphery of the rotating system and the deconfinement phase appears closer to the rotation axis. We argue that the anisotropy of the gluon action in the curved co-rotating background can quantitatively explain the remarkable property that the spatial structure of this inhomogeneous phase disobeys the picture based on a straightforward implementation of the Tolman-Ehrenfest law. We also perform the first lattice simulation of rotating $N_f=2$ QCD which confirms that a similar picture is expected for theory with dynamical quarks.

    ↳ hep-lathep-phhep-thPoS(2026)·1 citation
28. 28*

    Analytic Expressions for Shielded Halbach Multipoles

    Volker Ziemann

    We employ the method of images to derive analytic expressions for the magnetic field of Halbach multipoles that are enclosed in high-permeability shielding.

    ↳ physics.acc-phhep-phphysics.app-phMagn.·0 citations
29. 29*

    Universal and non-universal finite-volume effects in the vicinity of chiral phase transition in (2+1)-flavor QCD

    Sabarnya Mitra🇩🇪 · Jishnu Goswami🇩🇪 · Frithjof Karsch🇩🇪

    In this proceeding, we discuss the finite-size scaling analysis of the order parameter related to the chiral phase transition in QCD with two massless quarks. We use data obtained in lattice QCD calculations performed with highly improved staggered quarks (HISQ) for a range of light quark masses, $1/240\le m_{\ell }/m_s\le 1/27$ for different spatial volumes ($N_{\sigma }$) on Euclidean lattices with temporal extent $N_{\tau }=8$, satisfying $3N_{\tau }\le N_{\sigma }\le 10N_{\tau }$. We observe that infinite volume extrapolated data for the order parameter agree reasonably well with the expected $O(2)$ scaling behavior even for physical ratios of the light-to-strange quark mass ratio. We quantify deviations from asymptotic scaling and perform a detailed analysis of the influence of finite-size effects in terms of temperature and quark masses at a fixed lattice cutoff. This is crucial for improving the reliability of the infinite-volume extrapolated estimate of the chiral order parameter and for a more precise determination of chiral phase transition temperature from direct Lattice QCD simulations.

    ↳ hep-lathep-phhep-thnucl-ex+1PoS(2026)·2 citations
30. 30*

    The Axion-Photon Mixing and the Extragalactic Magnetic Background: Plateau Regimes, Resonances, and Non-Gaussian Boosts

    Andrea Addazi🇨🇳 · Yi-Fu Cai🇨🇳 · Salvatore Capozziello🇮🇹 · Qingyu Gan🇮🇹 · Gaetano Lambiase🇮🇹

    We present an analytical treatment of Axion-Like-Particle (ALP)--photon mixing with extragalactic background light (EBL) attenuation for constant, Gaussian-stochastic, and non-Gaussian magnetic field configurations--with direct implications for Very High Energy (VHE) gamma-ray observations such as LHAASO, HAWC, and CTA experiments. For constant fields, we derive exact probabilities and identify a perturbative plateau regime where photon survival scales as quartic order of magnetic field, isolating the four-point magnetic correlation as a sensitive probe of non-Gaussianity. For Gaussian stochastic fields, we obtain--for the first time--analytical formulas for non-exponential-decay components in the strong-attenuation regime. Contrary to the widely used domain-like model, photon survival is suppressed by 4-6 orders of magnitude, while both conversion and survival probabilities exhibit distinct multi-peak structures from mass-equal resonance, stochastic resonance, and EBL attenuation. Extending to non-Gaussian fields, we show that non-Gaussianity can enhance photon survival by several orders of magnitude relative to the Gaussian case, potentially explaining the unexpectedly VHE photon event observed by LHAASO. Our results demonstrate that stochastic magnetic fields cannot be reduced to domain-like coherence without losing essential physics, and that VHE gamma-ray spectra encode observable information about both the power spectrum and non-Gaussian structure of intergalactic magnetic fields--critical as next-generation observatories push toward PeV sensitivities.

    ↳ astro-ph.HEgr-qchep-phhep-thEPJC(2026)·0 citations
31. 31*

    Imprints of primordial magnetic fields in gravitational collapse during early structure formation

    Jennifer Schober🇨🇭 · Molly Abramson · Sayan Mandal🇺🇸 · Salome Mtchedlidze · Tina Kahniashvili🇺🇸

    Context. Primordial magnetic fields (PMFs) generated in the early Universe might have left observable imprints on present-day large-scale structure. However, the spatial scales on which primordial signatures are able to survive the nonlinear processes that accompany structure formation remain unclear. Aims. The aim of this study is to investigate the evolution of the statistical properties of PMFs during the onset of gravitational collapse. Methods. We performed a suite of high-resolution direct numerical simulations of isothermal self-gravitating, magnetized gas clouds. By varying the viscosity, we probed different Reynolds-number regimes and follow the coupled evolution of gravitational collapse and magnetohydrodynamic turbulence. Results. At sufficiently high Reynolds numbers, turbulence generated during collapse triggers the onset of a small-scale dynamo, which amplifies magnetic energy below the Jeans scale and modifies the magnetic energy spectrum significantly. The question of whether dynamo amplification dominates the magnetic field evolution is determined by the competition between the dynamo growth time and the free-fall time. Conclusions. Our results highlight the importance of resolving the Jeans scale and the associated turbulent inertial range in cosmological magnetohydrodynamic (MHD) simulations to accurately capture the interplay between gravitational compression and dynamo amplification and to assess which structures retain memory of primordial fields.

    ↳ astro-ph.COastro-ph.GAhep-phphysics.plasm-phAstron.Astrophys.(2026)·4 citations
32. 32*

    Polarisation Singularities of Gravitational Waves

    Claire Rigouzzo🇬🇧 · Sebastian Golat🇬🇧 · Alex J. Vernon🇪🇸 · Kyan Louisia🇬🇧 · Eugene Lim🇬🇧 · Francisco J. Rodriguez-Fortuno🇬🇧

    Departure from idealised plane waves gives rise to intricate geometric structures in wave fields. One such structure is the polarisation singularity, which emerges when multiple monochromatic waves interfere (such as would be the case for stochastic backgrounds), producing loci of purely circular or linear polarisation. In this work, we extend the theory of polarisation singularities to gravitational waves and higher spin fields. Building on the electromagnetic description, we formulate the gravitational analogue of polarisation singularities and show that they are generic features of gravitational waves. Their dimension, however, depends on the spin of the field. We illustrate these results with simulations of plane-wave interference and analyse the resulting singularity densities.

    ↳ gr-qcastro-ph.COhep-phphysics.optics0 citations
33. 33*

    Hyperon-Induced Inhomogeneous Pion Condensation and Moat Regimes in Neutron Star Cores

    Theo F. Motta🇧🇷 · Randall H. V. Pradinett🇧🇷 · Gastão Krein🇧🇷

    We perform a stability analysis of the homogeneous ground state of nuclear matter against inhomogeneous perturbations of the pion condensate. In $\beta$-equilibrium, restricting the baryon species to nucleons only, we observe no instability; however, at high densities, the pseudoscalar density-density correlations assume a moat regime, i.e. a damped oscillatory patterned spatial correlation, which in momentum space appears as a non-zero global minimum for some finite three-momentum. When hyperons are permitted to appear, this minimum can cross down to negative values, which configures an instability towards an inhomogeneous pion condensate which ultimately will affect the equation of state.

    ↳ nucl-thhep-phPRD(2026)·1 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.