HEP Phenomenology·hep-ph

Thu·Oct 15, 2026Thursday·October 15, 2026

42 papers—31 primary·11 cross-listed

01
Measuring $V_{c b}$ at electron-proton colliders
David Marzocca
We study the prospects for an independent determination of $V_{c b}$ from bottom-tagged charged-current deep-inelastic scattering at future electron-proton colliders: the EIC, LHeC, and FCC-eh. The transition $e^{-} c \to ν_{e} b$ probes $∣ V_{c b} ∣^{2}$ through a process with different theoretical and experimental uncertainties from semileptonic $B$ decays. We fit ratios of $b$ -tagged charged-current event counts over flavour-inclusive ones in kinematic bins, including correlated parton-distribution and flavour-tag calibration uncertainties, and floating the other CKM parameters. With projected parton distributions and tagging performance motivated by existing studies, we find a potential relative sensitivity in $∣ V_{c b} ∣$ of about $0.8%$ at the LHeC with $1 ab^{- 1}$ of integrated luminosity and $0.7%$ at FCC-eh with $2 ab^{- 1}$ . The corresponding EIC sensitivity is instead at the level of $20 - 30%$ , depending on the configuration. The LHeC could thus provide a high-energy determination competitive with low-energy ones, but with substantially different dominant systematic uncertainties, on the timescale of its proposed operation between the HL-LHC and FCC-ee. We identify precise flavour-tag calibration and control of the kinematic response as the main requirements for realising this potential sensitivity.
hep-phhep-ex
02
Direct Detection of Solar Neutrinos to Probe Tensions and Break Degeneracies in Long-Baseline Neutrino Experiments
Dorian W. P. Amaral · David Cerdeño · Andrew Cheek · Valeria Costa · Peter B. Denton · Patrick Foldenauer
Long-baseline (LBL) accelerator experiments are sensitive not only to the standard neutrino oscillation parameters but also to new physics. Currently, there exists a tension between NOvA and T2K data that can be explained by vector non-standard neutrino interactions (NSI) with complex couplings, which in turn introduce degeneracies in LBL measurements. We demonstrate that dark matter direct detection experiments can use their measurements of solar neutrinos to test the NSI resolution of this tension and to break these degeneracies. Using recent solar neutrino data from LZ, XENONnT, and PandaX-4T, we show that dark matter direct detection experiments already constrain part of the NSI solution of the NOvA-T2K tension. These experiments can also probe parts of the NSI parameter space that even DUNE will be blind to. Our analysis combines nuclear recoils from $^{8}$ B neutrinos and electron recoils from $pp$ neutrinos. A future xenon experiment, such as XLZD or PandaX-xT, will be able to cover a significant fraction of the NSI solution of the NOvA-T2K tension.
hep-ph
03
Exothermic dark-photon dark matter and the LZ high-recoil event: finite-reheating constraints
Kuldeep Deka
An excited dark-matter state can produce a high-energy nuclear recoil by releasing its mass splitting in a collision. Motivated by the $248$ ~keV LUX--ZEPLIN candidate, we study freeze-in of a $45$ ~GeV pseudo-Dirac particle with a $1$ ~MeV splitting and a $1$ ~GeV dark photon during non-instantaneous reheating. We choose a recoil normalization compatible with the published INTEGRAL/SPI three-photon decay limit. It predicts $0.43$ events in the LZ window and retains the reference recoil shape. Including both dark-photon and $Z$ exchange, we calculate production and entropy dilution for backgrounds with $T \propto a^{- α}$ and $ρ_{ϕ} \propto a^{- 3 (1 + ω)}$ . For $\Tmax = m_{χ}$ , the observed abundance requires $\Trh = 1.32$ ~GeV for matter-like constant-width reheating, $3.09$ ~GeV for quartic oscillations with scalar decay, and $0.588$ ~GeV for quartic oscillations with constant width, compared with $4.10$ ~GeV for instantaneous reheating. These finite-reheating solutions are insensitive to increasing $\Tmax$ above $m_{χ}$ . For $\Tmax \geq m_{χ}$ , adiabatic kination has no solution with $\Trh > 5.96$ ~MeV, the BBN-motivated cutoff adopted for our scans. At $α_{D} = 1 0^{- 10}$ , the estimated thermal-mediator source is below $0.2%$ of the Standard Model source, and self-conversion does not appreciably deplete the excited population. The calculation relates an exothermic recoil benchmark to the production and dilution history before radiation domination.
hep-ph
04
A spurionic interpretation of RG-stable parameter relations in the two-Higgs-doublet model
Zackaria Chacko · Shourya Mukherjee
Recent work on the two-Higgs-doublet model (2HDM) has uncovered basis-invariant relations among the parameters in the scalar potential that are stable under renormalization group (RG) evolution but do not coincide with any of the standard Higgs-family or Generalized- $CP$ symmetry classes of the scalar sector. These relations have subsequently been reformulated in terms of so-called GOOFy transformations. In this paper, we show that the same fixed surface admits a conventional interpretation in terms of spurions. The gauge-covariant kinetic terms of the 2HDM possess a Higgs-family $U (2)_{H}$ symmetry, and the couplings in the potential may be organized into irreducible spurions under its nontrivial $SU (2)_{H}$ subgroup. We first explain the one-loop closure in the spurion language and then establish stability to all orders in the scalar and gauge couplings in any mass-independent scheme. General Yukawa couplings introduce additional Higgs-family covariants and can spoil the scalar-sector selection rule. We therefore consider the six conventional Higgs-family and Generalized- $CP$ symmetries of the 2HDM, imposed as exact symmetries of the full Lagrangian, and show that closure is controlled by whether the relevant Higgs-family triplet contains an invariant direction. The spurion formulation thus provides a basis-covariant and conventional group-theoretic explanation of the RG stability of the 2HDM parameter relations.
hep-ph
05
Two-loop $g g \to AA$ amplitudes near threshold and the double parton scattering singularity
Arunima Bhattacharya
The two-loop amplitudes for pseudoscalar pair production in gluon fusion, $g g \to AA$ , with each pseudoscalar emitted from its own effective gluon vertex, are known in closed form, but large cancellations near threshold obscure their analytic structure. We expand the IR-finite amplitudes in the pseudoscalar velocity $β_{A}$ through $β_{A}^{6}$ at fixed scattering angle. All inverse powers of $β_{A}$ and the odd powers through $β_{A}^{5}$ cancel, and at leading power the angular dependence enters only through $ln (2 p_{T} / m_{A})$ . We identify this logarithm with the double parton scattering (DPS) singularity: with the overall constant fixed at threshold, the factorisation formula of Gaunt and Stirling reproduces the velocity dependence of its one-loop coefficient in the forward limit to $3 \times 1 0^{- 15}$ , and a one-loop $g g \to H H$ analysis confirms the corresponding CP-even weight. At two loops the equal-helicity amplitude grows as $ln^{3} p_{T}$ , with the leading logarithmic ratio of planar $N = 4$ super Yang-Mills theory, while the opposite helicity amplitude, which has no one-loop DPS logarithm, grows as $ln^{2} p_{T}$ . In the finite virtual correction, relative to the squared tree amplitude, the highest logarithm at order $α_{s}^{2}$ is $- \frac{7}{64} α_{s}^{2} N_{c}^{2} ln^{2} (2 p_{T} / m_{A})$ . For $β_{A} \leq 0.2$ the series reproduce the unexpanded amplitudes with relative errors of at most $6.77 \times 1 0^{- 5}$ at the tested points; they provide this two-loop contribution to the hard function for soft-gluon resummation of the pair invariant-mass distribution near $m_{AA} = 2 m_{A}$ and are released with code for their numerical evaluation.
hep-ph
06
Born-Oppenheimer chiral effective field theory and its application to $X_{b}$
Yu Zhang · Feng-Kun Guo · Christoph Hanhart · Alexey Nefediev · Paul Pütz
Following the discovery of the exotic state $X (3872)$ in the charmonium spectrum, the possible existence of an analogous state, $X_{b}$ , in the bottomonium sector has attracted considerable attention of the hadronic physics community. In this work, we lay the ground for the development of Born-Oppenheimer chiral effective field theory (BO $χ$ EFT), that allows us to include both quark and hadron degrees of freedom as well as the full complexity of the meson-exchange potential in a systematic way. For illustration, the formalism to leading order (LO) is applied to the system of $χ_{b 1}$ states and in particular the $X_{b}$ . The two parameters that are present at this order are constrained using experimental information on the bottomonium spectrum together with lattice input on static quark-antiquark potentials, including string breaking effects. The framework identifies the observed $1^{++}$ state at 10.513 GeV with a predominantly molecular $X_{b}$ , the bottom counterpart of the $X (3872)$ , and predicts an additional predominantly compact bottomonium state at 10.544 GeV, about 60 MeV below the $B B ˉ^{*}$ threshold.
hep-phhep-exhep-lat
07
Quasiparticle Modeling of Strongly Magnetized Strange Quark Systems
Yogesh Kumar · Manas Lohani · Poonam Jain · Pargin Bangotra · Vinod Kumar · T. A. Nahool · Om Prakash · Sanjay Tyagi
We examine spin-polarized Strange Quark Matter and the complex structure of Strange Quark Stars in the existence of a strong magnetic field. Our framework uses a quasiparticle model, en hanced by a QCD-informed effective quark mass dependent on both chemical potential value and magnetic field strength. The resulting Equation of State yields an energy per baryon below the iron limit, supporting the hypothesis that the actual ground state of matter is strange matter. The Tolman-Oppenheimer-Volkoff expressions are solved and find that the maximum stellar mass decreases with the degree of spin polarization, reaching as high as 2.35 Mo with a related radius 12.33 km. Furthermore, the model predictions for mass, radius, and surface redshift are in excel lent conformance to observational limitations for the massive pulsar PSR J0952-0607. These results highlight the crucial role of quasiparticle medium effects and strong magnetic fields in describing dense matter.
hep-phActa Physica Polonica B (2026)
08
Pythia-Contrib: a modular contribution framework for the Pythia 8 event generator
Benoit Assi · Christian Bierlich · Rikab Gambhir · Philip Ilten · Tony Menzo · Stephen Mrenna · Manuel Szewc · Michael K. Wilkinson · Jure Zupan
Pythia is a general-purpose Monte Carlo event generator used in particle, astroparticle, and nuclear physics, by theorists and experimentalists, to simulate particle collisions. Because of the size and diversity of the user community, it is challenging to address all of the needs for new and varied physics models. This paper describes the Pythia-Contrib system, which allows for third-party developers to contribute code to Pythia without introducing external software dependencies to the Pythia code base.
hep-phhep-ex
09
Effective Fermion-Photon Vertex in a Rotating Relativistic Medium: Tree-Level Structure
Jorge David Castaño-Yepes · Alejandro Ayala · J. E. Martínez-Herrera · Enrique Muñoz
We study the tree-level fermion-photon effective vertex for on-shell particles in a relativistic environment undergoing rigid rotation at zero temperature. The rotational background breaks translational invariance in the transverse plane and introduces a preferred direction, leading to a distinct decomposition of the vertex into longitudinal and transverse structures with respect to the rotation axis. Using fermion and photon modes constructed in the rotating frame, we derive the corresponding selection rules and show that the energy and the longitudinal component of the momentum are conserved, whereas no independent transverse momentum-conservation condition arises. Instead, the transverse dependence is governed by radial integrals involving three Bessel functions, whose support constrains the magnitudes of the transverse momentum projections. The vertex can be organized in a circular basis for the transverse components and a Cartesian basis along the rotation axis, and expressed in terms of six Dirac structures. Their coefficients define 24 form-factor components associated with the photon-mode components, physical photon states, and spin-dependent structures induced by the rotating background. We also verify current conservation and gauge invariance of the resulting tree-level matrix element under the boundary conditions considered. These results provide the tree-level structure of the fermion-photon interaction in rotating relativistic matter and establish the basis for the study of radiative corrections in vortical backgrounds.
hep-phhep-th
10
Bottom-Charm $[b c]$ Diquark Masses from QCD Laplace Sum-Rules
T. de Oliveira · D. Harnett · J. Ho · R.T. Kleiv · Siyuan Li · N. Loewen · A. Palameta · T.G. Steele
Constituent mass predictions for bottom-charm $[b c]$ color-antitriplet diquarks are generated using QCD Laplace sum rules. We calculate the diquark correlator within the operator product expansion to next-to-leading-order (NLO), including terms proportional to the four- and six-dimensional gluon and six-dimensional quark condensates. Existing analytic expressions for the resulting multi-scale master integrals are insufficient for these calculations, so we utilize numerical $D$ -dimensional loop integration techniques. The sum rule analyses stabilize in all four channels yielding constituent masses in GeV of: scalar ( $0^{+}$ ) $(5.60 \pm 0.56)$ , pseudoscalar ( $0^{-}$ ) $(6.04 \pm 0.60)$ , axial vector ( $1^{+}$ ) $(5.60 \pm 0.56)$ and vector ( $1^{-}$ ) $(5.99 \pm 0.60)$ . These constituent mass results are discussed in comparison with values used in diquark models of tetraquark hadronic states. We also summarize QCD sum rule predictions for diquark masses for all possible quark-flavor combinations, providing QCD-based criteria for assessing the diquark mass parameters used in constituent diquark models of hadrons.
hep-ph
11
Constraints on pion parton distributions at small $x$ from leading-neutron electroproduction data
C. Yang · P. C. Barry · W. Melnitchouk · N. Sato
We revisit the extraction of parton distribution functions (PDFs) in the pion in a global QCD analysis of pion--nucleus Drell--Yan and leading-neutron (LN) electroproduction data, in view of recent suggestions that uncertainties on the pion PDFs at small parton momentum fraction $x$ are dramatically underestimated. We perform a set of controlled fits that vary the LN data coverage, PDF parametrization, and positivity constraints, determining both the PDFs and pion-nucleon splitting functions simultaneously. While the use of a restricted H1 LN data sample used by the Fantômas group is found to enlarge the PDF uncertainties and admit solutions with vanishing gluon PDFs, our global analysis provides a good description of an extended H1 and ZEUS LN database, significantly reducing the parametrization dependence and strongly disfavoring a zero gluon distribution.
hep-phhep-exnucl-th
12
Magnetically Charged Black Holes from Grand Unified Theory
Tanmay Vachaspati · Anja Wachowitz
Grand Unified models of particle physics inevitably give rise to magnetic monopoles. Often the model will also contain a weakly broken discrete symmetry that leads to the formation of biased domain walls that survive for a limited period in cosmology. For a range of the discrete symmetry breaking parameter, domain walls can collapse to form magnetically charged extremal black holes lighter than $≃ 1 kg$ but these are not expected to survive until the present epoch due to Hawking evaporation and Schwinger pair production of monopoles. If the parameter is smaller still, the black holes may be astrophysical, with mass greater than $1 0^{15} g$ and with sub-extremal magnetic charge: $Q ≃ 1 0^{8}$ (for our canonical choice of parameters). The cosmological energy density in residual magnetic monopoles depends on the discrete symmetry breaking parameter and for sufficiently small values of the parameter, the magnetic monopole density can satisfy all observational constraints.
hep-phastro-ph.COhep-th
13
Thermal spectral functions of heavy and exotic Mesons from a hQCD at finite density
Zhou-Run Zhu · Zhanyuan Gao · Zhaohui Feng · Man-Li Tian · Defu Hou
In this work, we study spectral functions of heavy and exotic mesons in a self-consistent Einstein-Maxwell-dilaton model at finite temperature and chemical potential, where the dilaton is allowed to back-react on the geometry. A non-quadratic dilaton profile is introduced to reproduce the nonlinear Regge trajectories of heavy-flavor mesons, and the corresponding spectral functions are computed for charmonium, bottomonium, tetraquark, and hybrid channels. In all cases, increasing either temperature or chemical potential suppresses and broadens the quasiparticle peaks, signaling sequential in-medium dissociation; for each radial family, the 2S-like state melts before the 1S-like state. The predicted melting temperatures obey the mass ordering $T_{melt}^{π_{1} (1400)} < T_{melt}^{J / ψ} < T_{melt}^{Z_{c} (3900)} < T_{melt}^{Υ (1 S)}$ , with $T_{melt} ≃ 1.08, 2.96, 4.44$ , and $5.93 T_{c}$ , respectively, so heavier states remain bound up to higher temperatures. These results provide quantitative, testable predictions for heavy-ion experiments probing tetraquark and hybrid mesons in hot and dense QCD matter.
hep-ph
14
Superhorizon enhancement of the hydrodynamic GW tail in Standard Model embedded warm inflation
Simone Biondini · M. Laine
Hydrodynamic fluctuations in the primordial plasma generate a gravitational-wave (GW) background that grows like $f_{0}^{3}$ in terms of the current frequency. However, within the ( $1 0_{- 4} ...1 0_{4})$ Hz band of upcoming interferometers, the modes likely re-entered the Hubble horizon when the hydrodynamic noise was no longer at its maximal value. To address this situation, we define a model-independent transfer function for GWs generated by hydrodynamic (or other white-noise) fluctuations at any time. Employing appropriate variables, we show how this transfer function, together with the simpler vacuum one, can be determined numerically for a general expansion history. The results are illustrated for Standard Model embedded warm inflation scenarios, including both the vacuum and hydrodynamic parts. Following previous estimates, we find that a pre-exit-generated hydrodynamic tail becomes almost flat below $(1 0_{5} ...1 0_{7})$ Hz. Its small- $f_{0}$ intercept remains finite, and can then moderately influence observational constraints through the tensor-to-scalar ratio ( $r$ ).
hep-phgr-qc
15
Radion/Dilaton portal freeze-in dark matter in extra-dimensional theories
Amrita Mukherjee · George Sanamyan · Dipan Sengupta
We perform a comprehensive analysis of a radion/dilaton portal freeze-in dark matter in models of stabilized warped extra-dimensions. We show that the relic abundance of a generic dark matter particle (scalars, vectors, or fermions) is obtained via the conformal coupling of the radial mode in a consistent model stabilized warped extra- dimensions; our calculations show that in scenarios where the reheating temperature is much smaller than the radion mass, keV-TeV scale dark matter particles can saturate the relic density. We perform a comprehensive analysis of a radion/dilaton portal freeze-in dark matter in models of stabilized warped extra-dimensions. We show that the relic abundance of a generic dark matter particle (scalars, vectors, or fermions) is obtained via the conformal coupling of the radial mode in a consistent model stabilized warped extra- dimensions; our calculations show that in scenarios where the reheating temperature is much smaller than the radion mass, keV-TeV scale dark matter particles can saturate the relic density. Furthermore, we show that the model is subject to Lyman-alpha constraints in the keV-GeV range, providing a unique, model-independent probe of this sector. Our calculations extend previous attempts to calculate the freeze-in relic abundance in extra-dimensional portals by providing a consistent theoretical calculation of matrix elements, clearly laying out the underlying motivation and assumptions and providing a comprehensive account of the cosmological constraints on the model.
hep-phastro-ph.HEhep-th
16
Decoherence as a Detector-Resolution Flow
Yao Ji · Yuqi Wang
We consider the QED final-state radiation modeled by $γ γ^{*} \to π^{+} π^{-} + X$ , including its finite-temperature generalization, as an open quantum system, and study the evolution of the pion-pair momentum density matrix as the detector resolution scale is varied. We derive an explicit relation between the Lindblad jump operator and the Wilson line associated with soft photon radiation. We find that real emission and virtual correction serve as two separate contributions to momentum decoherence, and together they give rise to the real--virtual cancellation at the density-matrix level. The external finite-temperature photon bath modifies the decoherence rate by a Bose factor consistent with the Feynman--Vernon influence-functional approach. We emphasize that our conclusions also apply to hard fermion production thanks to the universality of the soft radiation.
hep-ph
17
Quantum-enhanced Search for Galactic Dark Photons Using Cat-State Cavities
Aoying Wang · Yanjie Zeng · Yanyan Cai · Jing Shu · Bin Xu · Yuan Xu · Pan Zheng
We present a quantum-enhanced search for the Galactic dark-photon background (GDPB), a relativistic and anisotropic vector field that can be produced by dark-matter decay or annihilation in the Milky Way halo. We reinterpret an existing quantum-enhanced dark-photon dataset obtained with a superconducting circuit QED platform originally developed for wave-like dark-photon dark-matter searches, consisting of a high- $Q$ niobium cavity in the $TM_{010}$ mode dispersively coupled to a transmon qubit. By preparing four-component cat states and performing repeated quantum non-demolition parity measurements, analyzed with a hidden Markov model, we extract photon-transition probabilities for multiple cat amplitudes and integration times. The coupling to the GDPB is governed by a polarization- and angle-dependent cavity overlap function, which predicts a distinctive diurnal modulation of the excitation rate for both longitudinal and transverse polarizations. From the absence of such modulation, we set 90\% confidence-level bounds on the kinetic-mixing parameter $ϵ$ for two benchmark production mechanisms (parametric and cascade decay) over the relativistic mass range $m_{X} ≪ ω_{c}$ .
hep-phhep-exquant-ph
18
The Semileptonic B Frontier: LHC, B-factories, Lattice QCD & the Hunt for Precision
F. De Fazio · P. De Simone · M. Fedele · G. Finocchiaro · F. Mescia · M. Rotondo · A. Barone · B. Capdevila · M. De Cian · L. Dreyfus · M. Fael · G. Finauri and 24 other authors
This review document summarizes the main outcomes and key theoretical and experimental developments discussed at the workshop ``The Semileptonic $B$ Frontier: LHC, $B$ -Factories, Lattice QCD & the Hunt for Precision'', held at Laboratori Nazionali di Frascati on 16--18 February, https://agenda.infn.it/event/49469/. Bringing together experimentalists and theorists, the meeting addressed recent advances and outstanding challenges in both charged-current ( $b \to c / u ℓ ν$ ) and neutral-current ( $b \to s ℓ^{+} ℓ^{-}$ ) semileptonic $b$ -hadron decays. We synthesize current experimental measurements from Belle, Belle~II, and LHCb with state-of-the-art theoretical inputs---including Lattice QCD determinations, Heavy Quark Expansion (HQE) frameworks, and QED radiative corrections. In addition to reviewing the status of CKM matrix elements, hadronic form factor extractions, and Lepton Flavor Universality (LFU) tests, this report highlights novel observables and fitting techniques designed to maximize the sensitivity of future analyses and guide upcoming data-taking campaigns.
hep-ph
19
The dead-cone effect in charm, bottom and top quark jets in angular and momentum space
Redamy Perez-Ramos · Stefan Kluth · Wolfgang Ochs
The dead-cone effect reflects the mass dependence of QCD radiation from heavy quarks. We investigate this phenomenon from charm and bottom to top quarks using two-dimensional angular distributions and single-particle inclusive momentum spectra. The angular distributions illustrate the depletion of radiation around the heavy-quark direction, while the momentum spectra provide a quantitative observable of the effect. For charm and bottom jets, fragmentation functions reconstructed from LEP data at the $Z$ pole exhibit a strong suppression of high-momentum particles, quantitatively described within the Modified Leading Logarithmic Approximation of perturbative QCD. The analysis is extended to $s = 1$ TeV using Monte Carlo simulations. A hypothetical stable-top sample isolates the primary top-quark radiation pattern, whereas the physical decay $t \to bW$ introduces coherent radiation from the $t b$ colour dipole, obscuring the primary dead cone. By exploiting the dependence on the $b$ -quark emission angle $Θ_{b}$ , we reconstruct the primary top-quark parton momentum spectrum through extrapolation to $Θ_{b} \to 0$ . In contrast, the small-angle gluon and parton distributions do not converge to the stable-top dead-cone pattern because of radiation from the decay $b$ quark. These findings establish the inclusive momentum spectrum as a robust quantitative observable of the top-quark dead-cone effect and provide a unified description of mass-dependent QCD radiation from charm to top.
hep-phhep-ex
20
Correlation between gravitational wave frequencies as a signature of new black hole physics
Ngo Phuc Duc Loc
We point out that for black holes (BH) of the same mass, despite of arising from two entirely different physical arguments, the peak frequency of the coarse-grained gravitational wave (GW) spectrum of gravitons $f_{peak}^{graviton}$ is very close to the peak frequency of the GW spectrum produced from binary BH mergers $f_{peak}^{merger}$ . In particular, we find that $f_{peak}^{graviton} / f_{peak}^{merger} \approx 2.3$ independent from BH mass or population. If BHs are still evaporating, the peak frequencies scale as $\propto M_{i}^{- 1}$ with $M_{i}$ is the initial BH mass. If BHs evaporated in the radiation (matter) dominated era, the peak frequencies scale as $\propto M_{i}^{1/2}$ ( $\propto M_{i}$ ) respectively after taking into account redshift effect. Any deviation from the aforementioned magical ratio would indicate new BH physics. The sweetest frequency ballpark to look for this correlation is around $1 0^{14} Hz - 1 0^{20} Hz$ where both GW spectra are allowed to have maximum amplitude. As a demonstration of what the new physics could be, we consider a phenomenological self-similar regular BH model of Hayward featuring a single hair parameter. The observed ratio of peak frequencies can be used to directly infer the hair parameter, along with crucial properties of the novel BH solution such as Hawking temperature, horizon size, and innermost stable circular orbit. We also comment on the pros and cons of correlating frequencies among other GW sources such as formation, population fluctuation, and sudden transition of adiabatic perturbation.
hep-phastro-ph.COgr-qchep-th
21
Spin and 3D structure: theoretical advances
Markus Diehl
Theoretical studies of hadron structure have made important progress since the previous DIS workshop in 2025. This talk reviews selected new results and developments, with a focus on spin dependent parton distributions, on transverse-momentum distributions and their rapidity dependence, on generalised parton distributions, and on the evaluation of power corrections.
hep-ph
22
Transport of hard probes in the glasma
Dana Avramescu
The quark-gluon plasma (QGP) formed in relativistic heavy-ion collisions at RHIC and the LHC thermalizes from an out-of-equilibrium state of strong classical gluon fields known as the glasma. Jets and heavy quarks, produced in the initial scatterings, traverse these pre-equilibrium fields, but the glasma stage is neglected in phenomenology, which may bias the extracted QGP transport coefficients. This thesis studies its impact on jet and heavy quark transport. The glasma is described in the Color Glass Condensate framework by solving the classical Yang-Mills equations on a real-time lattice. The fields initially form longitudinal electric and magnetic flux tubes whose transverse correlation length is set by the saturation scale $Q_{s}$ . Probes are studied with both classical transport equations and quantum evolution in the light-front Hamiltonian approach. The transport coefficients for jets and heavy quarks are much larger than in the QGP and anisotropic between transverse and longitudinal directions. The azimuthal decorrelation of back-to-back $c c ˉ$ pairs in the glasma is comparable to that from the QGP, making $D D ˉ$ angular correlations a potentially measurable glasma signature. The glasma also modifies the nuclear modification factor $R_{AA}$ , though the effect is moderate compared to the nuclear parton distribution contribution. A systematic gauge-invariance analysis shows that the distinction between kinetic and canonical momenta is essential when comparing classical and quantum results, and that Coulomb gauge fixing largely reduces gauge artifacts. Finally, the eikonal quantum evolution of a high-energy quark is studied with time-dependent Basis Light-Front Quantization. The resulting momentum broadening agrees with the classical estimates and lays the groundwork for including quantum radiation.
hep-phJYU Dissertations (1174) 2026, ISBN 978-9…
23
Thermal properties of the $ρ$ meson from a machine-learning-improved holographic QCD model
Jia-Jie Jiang · Han Tang · Danning Li · Lang Yu
The thermal properties of the $\rho$ meson are revisited within the soft-wall AdS/QCD framework. The dilaton background is calibrated against lattice QCD screening-mass data through a neural-network-assisted inverse procedure. Using this calibrated background, we compute the temporal vector spectral function and the lowest vector quasi-normal modes. The pole mass $m_{\mathrm{pole}}(T)$ and thermal width $\Gamma(T)$ are then extracted from the corresponding complex quasi-normal mode frequencies. Adopting the vanishing real part of the quasi-normal mode frequency, $\omega_{\mathrm{Re}}(T_d)=0$, as a criterion for meson dissociation, we estimate $T_d\approx168\,\mathrm{MeV}$. As the temperature increases, the thermal width grows, and the spectral function evolves from a narrow Breit-Wigner-like resonance peak into a transport peak, confirming the QNM prediction that the vanishing of the pole mass is accompanied by the emergence of a transport peak and making it difficult to identify a quasiparticle peak. A numerical extraction of the dispersion relation shows that the propagator can be described by a finite-temperature simple-pole form with momentum-dependent thermal width, characterized by a diffusion coefficient $D(T)$ and an effective propagation speed $u(T)$, whose temperature dependences are also extracted. This form modifies the usual relation between the screening and pole masses. These results may provide a useful reference for effective studies of the hot hadronic medium.
hep-ph
24
Displaced tracks as a signal of dark matter co-annihilation: a case study using inert doublet model at $e^{+} e^{-}$ collider
Hrishikesh Deka · Subhaditya Bhattacharya · Amir Subba · Ritesh K. Singh
Dark sector containing heavy (charged) particles with small mass splitting with dark matter (DM) can co-annihilate and produce correct relic density, evading direct detection bounds. In such compressed spectra, the charged state can be long-lived and decay to DM along with a very soft charged particle, giving rise to distinctive disappearing or kink track signatures at colliders. As an example, we consider the Inert Doublet Model (IDM), where the charged scalar $H^{\pm}$ can be nearly degenerate with the neutral DM state ( $H^{0}$ ), and produce a soft pion ( $π^{\pm}$ ) when it decays. We investigate this signature at a future $e^{+} e^{-}$ collider, focusing on electroweak $H^{+} H^{-}$ pair production and its displaced decays. By varying the mass splitting, we explore the transition from prompt soft-particle signatures to long-lived and disappearing-track signatures. Our analysis demonstrates the potential of future lepton colliders to probe the interplay between the charged-particle lifetime, its decay probability within the tracking volume, and the production rate sensitivity to the compressed DM scenarios over a broad range of masses, allowed by cosmological constraints.
hep-ph
25
Evolution of multihadron fragmentation functions with nonperturbative behavior
K. Makino · T. C. Rogers
QCD calculations that use multihadron fragmentation functions usually involve multiple invariant mass scales simultaneously, with only one being the hard scale associated with an overall hard process. The other scales are associated with relative internal motion intrinsic to the fragmenting parton and the multihadron system. Nonperturbative contributions to this later type of dependence attract interest for their association with intrinsic partonic structures, but care is needed in disentangling the truly nonperturbative effects from perturbative behavior and relating the former to universal nonperturbative matrix elements. To this end, we show how to evolve collinear multihadron fragmentation functions in a way that accounts for the simultaneous presence of these extra scales. The general multihadron fragmentation functions evolve in the same way as ordinary single hadron fragmentation functions, with the dependence on the extra scales separated out. We use this to unify treatments of perturbative and nonperturbative effects in multihadron systems in a way that optimizes for interpretations focused on partonic structure.
hep-phhep-thnucl-th
26
Strangeness suppression, the $ϕ$ meson and $Λ Λ ˉ$ spin correlations from exact strangeness conservation at the quark level
P. Castorina · H. Satz
In small collision systems strange hadrons are suppressed, and the suppression grows with the number of strange quarks. Exact strangeness conservation in a finite volume accounts for this, but when it is imposed on hadrons it leaves the $ϕ$ meson unsuppressed, contrary to observation. We impose the conservation law on the strange quarks in a causally connected cluster, before hadronization, and count separately the combinations of a strange quark with the antiquark created together with it. A pair created from the vacuum cannot form a $ϕ$ , a pair created from a gluon can only if it loses its color. With one function of multiplicity, the mean number of strange quarks per cluster, the model describes kaons, $ϕ$ , $Ξ$ and $Ω$ in pp and p--Pb collisions at the LHC; the data require that about half of the same-pair combinations are excluded from the $ϕ$ , and reject both an unsuppressed $ϕ$ and a $ϕ$ built only from different pairs at about five standard deviations. The same-pair combinations are those that carry the spin correlation observed in $Λ Λ ˉ$ production, whose dilution is thereby tied to the $ϕ$ suppression and is predicted to decrease with multiplicity
hep-ph
27
Brownian GPDs: A Stochastic Calculus Approach to Generalized Parton Distributions from Integral Constraints
Douglas Q. Adams · Simonetta Liuti · Zaki Panjsheeri · Brannon Semp
We present a stochastic calculus approach for modeling generalized parton distribution functions using information provided from lattice QCD calculations of Mellin moments, without assuming a functional form. Reconstructing the underlying dependence on the partonic momentum fraction from a limited number of moments constitutes an intrinsically non-unique inverse problem. Our goal is to provide a model agnostic way to determine GPDs subject to integral constraints. Thus, we derive and show usage of a controlled Langevin approach based on stochastic calculus and Brownian motion. The method combines a variational formulation, based on minimizing a Dirichlet action subject to the imposed constraints, with stochastic dynamics that generates an ensemble of admissible functions. The resulting ensemble provides a preferred reconstruction and characterizes the variability associated with incomplete integral information within the chosen stochastic model. The framework can accommodate general integral kernels and prescribed function values, offering a flexible approach to reconstructing functions from indirect constraints. Beyond its application to GPD phenomenology, the method provides a general strategy for investigating inverse problems in which integral observables are known but the underlying functional dependence remains undetermined. The approach may have more general applications beyond the scope of studying 3D hadron structure, and it is particularly useful in situations where we know definite integrals of functions with kernels, but do not know the underlying function.
hep-ph
28
Effects of quadratic frequency chirping and carrier-envelope phase on Schwinger pair production in polarized electric fields
Abhinav Jangir
We investigate electron-positron pair production in spatially homogeneous, time-dependent polarized electric fields using the Dirac-Heisenberg-Wigner formalism, focusing on the effects of symmetric and asymmetric quadratic frequency chirping and the carrier-envelope phase (CEP). Our analysis reveals how these field parameters govern both the momentum-space structure and the overall yield of the produced pairs. Frequency chirping substantially reshapes the momentum distributions by modifying their interference patterns and peak occupations. The momentum distributions are particularly sensitive to weak chirping, whereas strong chirping produces pronounced oscillatory and ring-like structures across all polarization states. The total pair yield increases with chirp strength, with symmetric chirping consistently producing a higher yield than asymmetric chirping for the parameter range considered. Moreover, the sensitivity of the total number density to polarization decreases progressively with increasing chirp strength, becoming negligible in the strongly chirped regime. The CEP further modifies the momentum distributions by altering their shapes and relative peak occupations, with the extent of these changes depending on the polarization state. Our findings establish a theoretical framework for exploring external-field configurations that optimize the yield of Schwinger pair production.
hep-ph
29
Top-Quark Mass Scheme Uncertainties in Higgs Boson Pair Production via Gluon Fusion
Clara Del Pio · Sebastian Jaśkiewicz · Rebecca von Kuk · Robert Szafron
We investigate theoretical uncertainties arising from the choice of the top-quark mass scheme in Higgs boson pair production via gluon fusion. First, we implement the resummation of the top-quark mass logarithms obtained for the $g g \to H H$ amplitude at high energy and study its phenomenological impact on cross sections. Second, we formulate a threshold-aware treatment of the top-quark mass based on short-distance mass definitions, combining an MSR description near the top-pair threshold with an $MS$ treatment in the high-energy regime. Within the dynamical prescription, the combined mass-scheme variation of the SM inclusive NLO cross section at $s = 14$ TeV is $_{- 0.2%}^{+ 5.2%}$ . This estimate provides an alternative to the conventional OS- $MS$ envelope.
hep-ph
30
Transient PULSE: Code for the Transient Propagation of UltraLight (pseudo)Scalars to Earth
Jason Arakawa · Charles Cheung · Muhammad Hani Zaheer · Volodymyr Takhistov · Marianna Safronova
We present Transient PULSE, a software package that numerically implements a previously developed source-to-detector framework for transient ultralight bosonic signals from astrophysical bursts. Predicting these signals relies on connecting the source emission spectrum to its evolution during propagation and the resulting observables at a terrestrial detector. The package discretizes a user supplied energy spectrum into momentum modes, propagates them through a specified matter density profile and constructs the time-frequency energy density distribution at Earth, accounting for dispersion and in-medium screening effects. This treatment accommodates non-Gaussian source spectra and provides inputs for detector specific analyses. A complementary analytical module estimates coupling sensitivities, arrival time delays and screening thresholds from parameterized source and detector properties.
hep-phastro-ph.HEastro-ph.IMphysics.comp-ph
31
A global analysis of $B ˉ \to D P$ and $B ˉ \to D ˉ P$ decays
Bhubanjyoti Bhattacharya · Rida Boumris · David London
Recently, a fit to the 15 measured branching ratios of $B ˉ \to D P$ decays ( $B = {B^{+}, B^{0}, B_{s}^{0}}$ , $D = {D^{0}, D^{+}, D_{s}^{+}}$ , $P \in {π, K}$ ) was performed under the assumption of flavor SU(3) symmetry [SU(3) $_{F}$ ]. A terrible fit was found: there was a $> 5 σ$ disagreement with the SU(3) $_{F}$ limit of the Standard Model [SM $_{SU (3)_{F}}$ ]. It was also found that this discrepancy can be removed by adding $\sim 20%$ SU(3) $_{F}$ -breaking effects. Now, the $B ˉ \to D^{0} P$ amplitudes can contribute to other observables (direct and indirect CP asymmetries) if they interfere with the amplitudes for $B ˉ \to D ˉ^{0} P$ decays. This happens if the $D^{0}$ and $D ˉ^{0}$ decay to the same final state (e.g., $K^{+} K^{-}$ , $π^{+} π^{-}$ , $K^{\pm} π^{\mp}$ , etc.). In this paper, we perform a combined fit of $B ˉ \to D P$ and $B ˉ \to D ˉ P$ decays, including all observables. We again find a $> 5 σ$ disagreement with the SM $_{SU (3)_{F}}$ , and we find that the data can be explained if $\sim 60%$ SU(3) $_{F}$ -breaking effects are included.
hep-ph
32
Stabilizer Rényi Entropy Without a Phase Reference
Jinwei Chu · Savan Kharel
Stabilizer Rényi entropy quantifies magic relative to a complete Pauli frame. In settings such as helicity states of massless particles, unsynchronized qubit registers, energy eigenbases, and systems under superselection rules, the computational basis may be fixed while the transverse Pauli axes remain unspecified. The stabilizer Rényi entropy then depends on the choice of those axes. We define a phase-averaged stabilizer Rényi entropy by averaging the Pauli moments before taking the logarithm. It is exactly invariant under independent local rephasings. For pure states, it vanishes precisely when the state is a stabilizer state in every phase convention. For a broad class of sparse supports, it reduces to a closed-form function of the basis-state probabilities alone. Within this class, the ceiling for $n$ channels is $ln [n^{3} / (6 n - 5)]$ for $n \geq 3$ and $ln \frac{7}{5}$ for two channels. We apply the invariant to tree-level gluon scattering at four and five points, where the helicity-basis phases are unspecified. It saturates the two- and three-channel ceilings: $ln \frac{7}{5}$ at four points and $ln \frac{27}{13}$ in $3 \to 2$ scattering. In same-helicity $2 \to 3$ scattering, it lies between a floor of $ln \frac{8}{7}$ and a ceiling of $ln \frac{184}{125}$ , reached in the resolved soft limit and particular collinear limits, respectively. In every configuration studied, the invariant is independent of the fixed external colors.
↳ quant-phhep-phhep-th
33
Audible curvaton: modulated phase transition as the origin of large-scale curvature perturbations and gravitational wave anisotropies
Wen-Yuan Ai · Gabriele Franciolini · Xin Wang · Xiang-Xi Zeng
We propose a post-inflationary first-order phase transition modulated by a light spectator field as the origin of primordial large-scale curvature perturbations. Spectator fluctuations acquired during inflation modulate the bubble nucleation history, generating curvature perturbations together with correlated intrinsic gravitational-wave (GW) anisotropies. We show that this mechanism can reproduce the observed amplitude of curvature perturbations while producing a loud stochastic GW background in the frequency bands of space-based detectors such as LISA, Taiji, and TianQin. A concrete benchmark yields strongly enhanced intrinsic GW anisotropies and a local primordial non-Gaussianity signal within reach of future large-scale-structure surveys.
↳ astro-ph.COhep-ph
34
Infrared-Finite Positivity Bounds in 4D Gravity
Ziyu Dong
We formulate an S-matrix bootstrap in an exactly flat half-space, where boundary reflection provides geometric infrared control for four-dimensional gravity. Under the channel positivity conditions, we obtain an infrared-finite positivity bound on local four-scalar Wilson coefficients that includes a finite gravitational correction of order $G_{N}$ and is derived from the full UV absorptive spectrum without specifying a UV theory, imposing a spectral ansatz, requiring weak coupling or expanding the spectrum perturbatively. At fixed dimensionless external state parameters, the coefficient of the leading gravitational correction is independent of the EFT scale and requires neither an arbitrary soft resolution scale nor a model-dependent UV scale. Gaussian wave-packet scattering localizes interactions within the flat region and directly probes bulk Wilson coefficients while exponentially suppressing sensitivity to the boundary. Long-range gravitons remain sensitive to the boundary and give a finite contribution. The smearing functional passes numerical positivity tests with general half-space absorptive kernels in both crossed channels. An explicit string example shows how boundary reflection suppresses the collective contribution of string resonances to the absorptive part of the amplitude, connecting infrared control of low-energy scattering to the UV spectrum of quantum gravity in the same dispersion relation. The framework opens a route to infrared-finite constraints on effective interactions across particle physics and gravity.
↳ hep-thhep-ph
35
Chandra-JWST Probing the Effects of Moderate X-Ray Superflares on Protoplanetary Disks
Konstantin V. Getman · Kevin L. Luhman · Bayron Portilla-Revelo · Christian Rab · Valentin Brunn · Eric D. Feigelson · Arjan Bik · Jan Forbrich · Jenny Frediani · Thomas J. Haworth · Charles J. Law · Marco Padovani and 8 other authors
Powerful X-ray flares from young stars may rapidly alter the physical and chemical conditions of their planet-forming disks, but direct observational tests remain scarce. We present a Chandra-JWST/NIRSpec study of infrared spectral variability associated with pre-main-sequence (PMS) X-ray flares in the Orion Nebula. Combining six Chandra/ACIS-I observations with three NIRSpec-MOS visits, we analyze two-epoch spectra of 10 X-ray Flare stars and 12 matched non-flaring Controls among 84 observed disk-bearing PMS stars. We investigate three diagnostics: narrow 2.8-4.3 micron features, HI Br-alpha, and the CO fundamental band. Flare stars show tentative evidence for relatively fewer variable narrow features at longer wavelengths than Controls, while feature incidence decreases strongly with projected distance from the dominant ionizing O star Theta1 Ori C. Most classifiable features appear in absorption. These properties suggest that at least some features may arise in externally irradiated disk atmospheres and/or associated photoevaporative flows, with their apparent epoch-to-epoch variability potentially reflecting spatial sampling of such locally structured material rather than intrinsic temporal changes. Br-alpha behaves differently: flare stars show systematically stronger variability and uniquely exhibit absorption-core profiles, suggesting control by magnetospheric accretion and stellar magnetic processes rather than disk irradiation. The CO fundamental band shows no significant flare-associated variability, consistent with thermochemical models predicting weak responses to moderate X-ray superflares. This pilot study demonstrates the potential of coordinated Chandra-JWST observations to probe how young stellar magnetic activity affects planet-forming environments, motivating future monitoring to build larger superflare samples and extend them into the rare X-ray mega-flare regime.
↳ astro-ph.SRastro-ph.EPhep-ph
36
Binding energies in the $0^{-+}$ and $1^{--}$ fermion--antifermion channels from the ladder Bethe-Salpeter and Schrödinger equations
Wei He · Hai-Qing Zhou
In this work, we calculate the binding energies of an equal-mass fermion--antifermion system in the $0^{-+}$ and $1^{--}$ channels from the ladder Bethe--Salpeter (BS) equation with scalar, pseudoscalar, and vector exchange. The results are compared with those of the Schrödinger equation with the corresponding leading static interaction in two regimes: pointlike massless exchange at weak coupling and finite-mass exchange with monopole form factors at stronger coupling. For the BS calculation, we use two independent numerical methods based on momentum-space integral equations and coordinate-space differential equations. The differential-equation method gives estimated relative binding-energy errors below $1 0^{- 9}$ in both regimes. For massless vector exchange in Coulomb gauge, the numerical results are consistent with the uncrossed-ladder perturbative spectrum through the $O (m α^{5})$ terms. The results for massless scalar exchange and vector exchange in Feynman gauge are consistent with the common Wick--Cutkosky expansion through order $m α^{3}$ . For finite exchange masses, the differences from the leading static Schrödinger spectra at the same masses, couplings, and form factors depend strongly on the exchange and channel. Scalar exchange gives nearly degenerate channels with much weaker binding than the Schrödinger reference. In contrast, vector exchange with only the metric term retained gives stronger binding than the Schrödinger reference in $0^{-+}$ and weaker binding in $1^{--}$ . Notably, retaining the full Proca numerator substantially increases the vector binding in both channels. Pseudoscalar exchange also supports bound states and favors $1^{--}$ , although its leading static central interaction vanishes.
↳ nucl-thhep-ph
37
Correlation of galactic very-high-energy gamma-ray sources detected by LHAASO with high-energy neutrinos
Long-Yu Zhang · Kai Wang
We conducted an investigation into the possible correlation between very-high-energy (VHE, $E >$ 0.1 TeV) gamma-ray sources, as identified by the Large High Altitude Air Shower Observatory (LHAASO), and high-energy neutrino events captured by the IceCube Neutrino Observatory. For this analysis, we utilized the First LHAASO catalog, which comprises 90 VHE gamma-ray sources, and the IceCube Event Catalog of Alert Tracks (IceCat-1), which includes 348 track-like neutrino events. Through Monte Carlo simulations, we assessed the correlations between the neutrino events and LHAASO sources, achieving the best p-values of 0.237, 0.312, and 0.115, respectively, for all LHAASO sources, KM2A sources, and WCDA sources. These findings imply that the spatial coincidence between LHAASO sources and neutrino alerts is relatively weak. Furthermore, under the assumption that gamma-rays are exclusively generated through hadronic interactions, we estimated the most optimistic theoretical neutrino fluxes from LHAASO sources and compared them with the IceCube observed fluxes. The results indicate that the majority of these sources are improbable counterparts to the detected neutrinos. In conclusion, LHAASO sources could be potential galactic neutrino emitters but currently do not exhibit compelling evidence, thereby underscoring the necessity for elevated sensitivity levels in forthcoming detection instruments like IceCube-Gen2.
↳ astro-ph.HEhep-ph
38
Constraint on particle mass of dark matter based on XTE J1814-338 observation and DANS model
Lin Wang · Dehua Wen
The small observed radius of neutron star XTE J1814-338 (with mass of $1.2 1_{- 0.05}^{+ 0.05}$ $M_{⊙}$ and radius of $7_{- 0.4}^{+ 0.4}$ $km$ ) poses a great challenge to the traditional neutron star model composed of normal nuclear matter. The dark matter admixed neutron star (DANS) model provides a clue to solve this challenge. By employing the self-interacting fermionic dark matter model, we investigate the effects of dark matter parameters including the particle mass, self-interaction strength, and mass fraction of dark matter on the properties of DANSs. Our results indicate that the joint constraints from the observation of XTE J1814-338 and the astrophysical limits on the dark matter self-interaction cross section derived from observations of different colliding galaxy clusters can provide effective constraints on the particle mass of dark matter. Specifically, to simultaneously satisfy the small radius of XTE J1814-338 and the self-interaction limit, the particle mass of self-interacting fermionic dark matter is constrained to the range from sub-GeV to a few GeV.
↳ astro-ph.HEastro-ph.SRhep-phChinese Physics C Vol. 50, No. 11 (2026) …
39
MoEDAL-MAPP: the first dedicated search experiment at the LHC
John R. Ellis · Nick E. Mavromatos · Vasiliki A. Mitsou · James L. Pinfold
This special issue brings together a collection of original research articles and review papers addressing topics directly related to the MoEDAL-MAPP experiment at the Large Hadron Collider (LHC). The experiment is designed to search for (meta-)stable, anomalously ionising particles predicted by theoretical extensions of the Standard Model. Several contributions explore the theoretical and phenomenological aspects of models of particular relevance to the experiment, including scenarios involving magnetic monopoles, highly electrically charged particles, and millicharged particles. Other contributions focus on experimental developments, highlighting novel detection techniques and technological advances aimed at identifying these unconventional signatures and probing new phenomena beyond the Standard Model.
↳ hep-exhep-phhep-thphysics.ins-detEur.Phys.J.ST 235 (2026) 25, 5353-5359
40
The stability of non-Abelian $A_{4}$ vortices in $S O (3)$ gauge theory
Yoshihiko Abe · Tetsutaro Higaki · Kazuya Murakami · Muneto Nitta · Ryo Yokokura
We study the linear energetic stability of non-Abelian vortices in an $S O (3)$ gauge-Higgs theory with residual gauge group $A_{4}$ . In our previous work, we identified two families of such vortices associated with order-two and order-three elements of $A_{4}$ , and found Bogomol'nyi--Prasad--Sommerfield-like behavior at special ratios of the Higgs and gauge-boson mass scales. Here, we investigate their stability against $S O (3)$ gauge and Higgs perturbations by analyzing the second order variation of the vortex tension using analytical and numerical methods. In particular, when all relevant mass scales are equal, we prove linear stability for all vortices in the order-three family. By contrast, at the same mass point, we prove that a vortex in the order-two family is unstable. Thus, although both vortex families exhibit Bogomol'nyi--Prasad--Sommerfield-like behavior in their reduced equations at this mass point, their stability properties in the full $S O (3)$ theory are qualitatively different.
↳ hep-thhep-phmath-phmath.MP
41
Excited-State Effects in Nucleon Sigma Terms from a Variational Analysis
Constantia Alexandrou · Giannis Koutsou · Yan Li · Srijit Paul · Ferenc Pittler
We investigate excited-state effects in nucleon sigma-terms in lattice QCD using twisted-mass clover-improved fermion ensembles. We study correlation functions with nucleon and multihadron nucleon- $σ$ -meson interpolating operators. The analysis is performed using three gauge ensembles, including one ensemble simulated with two degenerate light, a strange, and a charm quark with quark masses tuned to approximately their physical value. We solve the generalized eigenvalue problem that arises from the matrix of correlators and show that the three-point function for the light sigma-term obtained using the optimal linear combination of interpolating operators has substantially reduced time dependence without loss of statistical precision. We apply Laplace filtering and investigate residual excited-state contributions in the extraction of $σ_{π N}$ . Using the same optimal linear combination of correlators as for $σ_{π N}$ for the strange sigma-term we also observe suppressed excited state contributions over an extended range of source--sink time separations. For the charm sigma-term, we observe negligible time dependence within the large statistical uncertainties, and these improvements show no significant effect.
↳ hep-lathep-phnucl-th
42
Can bosenovae deplete the galactic dark matter?
Samuel Gómez Gómez · Joshua Eby
No: neither through the bosenovae of gravitational atoms formed around stars and compact objects, nor through those of boson stars formed in the galactic dark-matter halo. We assume that all the dark matter consists of ultralight bosons with attractive self-interactions, which can be captured in the gravitational potential of astrophysical objects or condense into self-gravitating configurations. When these systems collapse in a bosenova, part of their mass is turned into relativistic radiation that escapes the galaxy. We bound the mass that a single object can eject and sum it over realistic models of the Milky Way and of other types of galaxies. For gravitational atoms, with realistic stellar populations and stellar evolution, the stars of the Milky Way deplete at most $ϵ_{⋆}^{GA} ≃ 3 \times 1 0^{- 9}$ of its halo, and the pump is equally negligible in other galaxies. The central black hole, Sgr A $^{*}$ , could reach $ϵ^{GA} \sim 1 0^{- 3}$ , but only for a boson mass disfavoured by ultrafaint dwarf galaxies and beyond the validity of the perturbative treatment, where only a geometric bound on the dark matter flux is available. For boson stars feeding on the rest of the halo, these would radiate at most $\sim 3 \times 1 0^{- 5}$ of the Milky-Way halo and $0.1%$ of a DF2-like one.
↳ astro-ph.HEastro-ph.COastro-ph.GAhep-ph