In this work, we construct the <italic>D</italic>-wave isoscalar <math altimg='si1.svg'><mrow><mi>&#960;</mi><mi>&#960;</mi><mo linebreak='goodbreak'>/</mo><mi>K</mi><mover accent='true'><mi>K</mi><mo>&#175;</mo></mover></mrow></math> coupled-channel Omn&#232;s matrix, formulated to satisfy unitarity, analyticity, and the appropriate asymptotic behavior. We employ a two-channel <italic>K</italic>-matrix model containing poles associated with the <italic>f</italic> <inf>2</inf>(1270) and <math altimg='si7.svg'><mrow><msubsup><mi>f</mi><mrow><mn>2</mn></mrow><mo>&#8242;</mo></msubsup><mrow><mo>(</mo><mn>1525</mn><mo>)</mo></mrow></mrow></math> resonances. The resulting unitary scattering matrix, which reproduces the experimental <italic>&#960;&#960;</italic>&#8239;&#8594;&#8239; <italic>&#960;&#960;</italic> and <math altimg='si27.svg'><mrow><mi>&#960;</mi><mi>&#960;</mi><mo>&#8594;</mo><mi>K</mi><mover accent='true'><mi>K</mi><mo>&#175;</mo></mover></mrow></math> data and PDG information, serves as input to the homogeneous two-channel Muskhelishvili-Omn&#232;s equation. We compare our Omn&#232;s matrix with previous constructions based on <math altimg='si27.svg'><mrow><mi>&#960;</mi><mi>&#960;</mi><mo>&#8594;</mo><mi>K</mi><mover accent='true'><mi>K</mi><mo>&#175;</mo></mover></mrow></math> phases extracted from sums of Breit-Wigner amplitudes. The Omn&#232;s matrix developed here provides a reliable dispersive input for form-factor calculations and resonance studies in the tensor-meson sector. As an application, we show that it enables a simultaneous and accurate description of the BESIII <italic>J</italic>/ <italic>&#968;</italic>&#8239;&#8594;&#8239; <italic>&#960;</italic> 0 <italic>&#960;</italic> 0 <italic>&#947;</italic> and <italic>J</italic>/ <italic>&#968;</italic>&#8239;&#8594;&#8239; <italic>K<inf>S</inf>K<inf>S</inf>&#947;</italic> spectra in the <math altimg='si2.svg'><mrow><mi>J</mi><mo linebreak='goodbreak'>=</mo><mn>2</mn></mrow></math> electric-dipole (E1) partial wave.

Germany

Igor Danilkin

Oleksandra Deineka

United States

Spain

Emilie Passemar

Marc Vanderhaeghen

Coupled-channel Omnès matrix for the <italic>D</italic>-wave isoscalar <math altimg='si1.svg'><mrow><mi>&#960;</mi><mi>&#960;</mi><mo linebreak='goodbreak'>/</mo><mi>K</mi><mover accent='true'><mi>K</mi><mo>&#175;</mo></mover></mrow></math> system and its application to <italic>J</italic>/ <italic>&#968;</italic>&#8239;&#8594;&#8239; <italic>&#960;</italic> 0 <italic>&#960;</italic> 0 <italic>&#947;</italic>,&#8201; <italic>K<inf>S</inf>K<inf>S</inf>&#947;</italic>

We derive a parameter-free geometric constraint on residue phases dictated by the pole-threshold angle. Using the <italic>N</italic>(2190) anomaly as a test case, this constraint reveals a sign ambiguity in prior data; correcting the sign ambiguity yields a phase of <math altimg='si13.svg'><mrow><mo>&#8722;</mo><msup><mn>28</mn><mo>&#8728;</mo></msup><mo>&#177;</mo><msup><mn>10</mn><mo>&#8728;</mo></msup></mrow></math>, matching our prediction. This consistency validates the method as a model-independent diagnostic for distinguishing compact from molecular states, offering a rigorous tool for exotic spectroscopy.

Croatia

S. Ceci

Bosnia and Herzegovina

R. Omerović

H. Osmanović

M. Uroić

United Kingdom

M. Vukšić

B. Zauner

Geometric constraint on residue phases: resolving the <italic>N</italic>(2190) anomaly and implications for exotic states

We investigate low-energy <italic>N&#981;</italic> scattering driven by a pole-enhanced triangle-like diagram, in which the two-Kaon-exchange contribution is promoted by the near-threshold &#923;(1405) pole in the <math altimg='si3.svg'><mrow><mi>N</mi><mover accent='true'><mi>K</mi><mo>&#175;</mo></mover></mrow></math> subsystem. Using an unphysical Kaon mass motivated by lattice simulations, we evaluate the <italic>N&#981;</italic> scattering length and find that this mechanism generates an attractive interaction with a magnitude of <math altimg='si7.svg'><mrow><mo>&#8722;</mo><mn>1.1</mn></mrow></math> to <math altimg='si8.svg'><mrow><mo>&#8722;</mo><mn>0.5</mn><mspace width='0.16em' /><mtext>fm</mtext></mrow></math>. Spin-dependent effects are not treated explicitly and are expected to provide subleading corrections in the near-threshold region. We further analyze the low-energy behavior of the triangle-like diagram amplitude and show that the scattering length depends on the parameter <italic>&#948;</italic>, defined as the mass difference between the <math altimg='si9.svg'><mrow><mi>K</mi><mover accent='true'><mi>K</mi><mo>&#175;</mo></mover></mrow></math> threshold and the <italic>&#981;</italic> meson, and the pole position of &#923;(1405), where the &#923;(1405) plays a crucial role to understand <italic>N&#981;</italic> interaction. Furthermore, by employing physical hadron masses, our calculated scattering length is found to be consistent with current experimental data, providing a unified description across both unphysical and physical mass regimes. This type of interaction differs from that associated with van der Waals-type forces or the long-range tail of two-pion exchange, highlighting the role of three-body dynamics encoded in the pole-enhanced triangle-like diagram in shaping the near-threshold <italic>N&#981;</italic> interaction.

China

Mao-Jun Yan

Chun-Sheng An

Cheng-Rong Deng

Low-energy <italic>N&#981;</italic> scattering from a pole-enhanced triangle diagram

Quantum information science has been broadly explored in Einstein gravity and in various modified gravity theories; however, its extension to quantum gravity settings remains largely unexplored. Motivated by this gap, in this paper we investigate the degradation of quantum entanglement of scalar and Dirac fields in the third-type black hole geometry arising from effective quantum gravity, which incorporates generic quantum gravitational corrections beyond classical general relativity. This quantum corrected spacetime is free of a Cauchy horizon and can be cast into a Rindler form in the near-horizon regime, allowing a direct identification of vacuum modes and a clear correspondence with the framework developed for uniformly accelerated observers. Within this framework, we compute the quantum entanglement and mutual information of uniformly entangled detector pairs in terms of the quantum parameter <math altimg='si6.svg'><mover accent='true'><mi>&#950;</mi><mo>&#732;</mo></mover></math>, the mode frequency <math altimg='si7.svg'><mover accent='true'><mi>&#969;</mi><mo>&#732;</mo></mover></math>, and Bob&#8217;s radial position <italic>R</italic> <inf>0</inf>. The quantum parameter <math altimg='si6.svg'><mover accent='true'><mi>&#950;</mi><mo>&#732;</mo></mover></math> consistently weakens the horizon-induced loss of correlations. For scalar fields this effect is pronounced, producing clear departures from the classical behavior, whereas for Dirac fields the familiar correlation pattern remains intact but its degradation is noticeably reduced. Overall, <math altimg='si6.svg'><mover accent='true'><mi>&#950;</mi><mo>&#732;</mo></mover></math> acts as a universal protective factor against gravitational suppression of quantum correlations. The third-type effective quantum black hole therefore provides a controlled and physically transparent arena for probing how quantum-gravity corrections influence relativistic quantum information.

Xiaobao Liu

Wentao Liu

Shu-Min Wu

Entanglement degradation of static black holes in effective quantum gravity

We propose to investigate short-range correlations (SRCs) in nuclei by studying sub and near-threshold photoproduction of <italic>&#981;</italic>-meson. The feasibility of exploring this nuclear structure in electron-positron collision experiments such as Beijing Spectrometer III (BESIII) and Super <italic>&#964;</italic>-Charm Facility (STCF) was investigated by utilizing their beryllium-based ( 9Be) beam pipe. The cross sections for these processes as well as the likelihood of detection by BESIII and STCF are calculated. Due to the limited number of events, BESIII is inadequate for the proposed measurement, while the future STCF provides a higher probability of successfully measuring this process. These findings suggest that electron-positron collider could play a valuable role in elucidating the fundamental physics behind the nuclear modification of parton distribution functions. This proposed analysis of photon-nucleon interactions represents uncharted territory, promising fresh prospects for applications in both particle and nuclear physics.

Wei Wang

Ji Xu

Xing-Hua Yang

Ya-Teng Zhang

Shuai Zhao

Exploring nucleon structure through sub- and near-threshold <italic>&#981;</italic>-meson photoproduction

The neutron energy spectrum measured at the Earth’s surface shows three distinct peaks: a thermal energy peak, an evaporation peak between 2-3 MeV, and a cascade peak near 100 MeV. However, the spectrum measured at a depth of 1604 metres water equivalent reveals the absence of cascade peak. This indicates an effective shielding of cosmogenic component of neutron background by the rock overburden. A comprehensive analysis of measured neutron fluence data from various facilities, combined with simulation data, indicates that the radiogenic component is the primary source of neutron background at the underground laboratories even at a depth of 1000 metres water equivalent. The concentrations of uranium and thorium in the surrounding rock are identified as the major factors influencing this background.

India

Sujoy Chatterjee

K. Banerjee

S. Dawn

Arijit Sen

S. Manna

A.K. Bakshi

Pratap Roy

V.N. Jha

R. Datta

B.K. Sapra

Depth-dependent background neutron distribution at the deep underground laboratory

In this work, we investigate the relativistic structure of white dwarfs (WDs) within the framework of modified gravity theory <math altimg='si3.svg'><mrow><mi>f</mi><mrow><mo>(</mo><mi>R</mi><mo>,</mo><mi>T</mi><mo>,</mo><msub><mi>L</mi><mi>m</mi></msub><mo>)</mo></mrow><mo linebreak='goodbreak'>=</mo><mi>R</mi><mo linebreak='goodbreak'>+</mo><mi>&#945;</mi><mi>T</mi><msub><mi>L</mi><mi>m</mi></msub></mrow></math>, which introduces a non-minimal coupling between matter and curvature. Using a realistic equation of state (EoS) that includes contributions from a relativistic degenerate electron gas and ionic lattice effects, we solve the modified Tolman-Oppenheimer-Volkoff (TOV) equations for two standard choices of the matter Lagrangian density: <math altimg='si9.svg'><mrow><msub><mi>L</mi><mi>m</mi></msub><mo linebreak='goodbreak'>=</mo><mi>p</mi></mrow></math> and <math altimg='si6.svg'><mrow><msub><mi>L</mi><mi>m</mi></msub><mo linebreak='goodbreak'>=</mo><mo>&#8722;</mo><mi>&#961;</mi></mrow></math>. We show that the extra <italic>&#945;TL<inf>m</inf></italic> term significantly alters the mass-radius relation of WDs, especially at high central densities <math altimg='si11.svg'><mrow><mo>(</mo><msub><mi>&#961;</mi><mi>c</mi></msub><mo>&#8819;</mo><msup><mn>10</mn><mn>8</mn></msup><mo linebreak='goodbreak'>&#8722;</mo><msup><mn>10</mn><mn>9</mn></msup><mspace width='0.16em' /><mrow><mi mathvariant='normal'>g</mi></mrow><mo linebreak='goodbreak'>/</mo><mi>c</mi><msup><mi>m</mi><mn>3</mn></msup><mo>)</mo></mrow></math>, allowing for stable super-Chandrasekhar configurations. In particular, depending on the sign and magnitude of the parameter <italic>&#945;</italic>, the maximum mass can increase or decrease, and in some regimes, the usual critical point indicating the transition from stability to instability disappears. Our findings suggest that <italic>f</italic>( <italic>R, T, L<inf>m</inf></italic>) gravity provides a viable framework to explain the existence of massive WDs beyond the classical Chandrasekhar limit. Using Bayesian inference with WD observational data, we further constrain the coupling parameter <italic>&#945;</italic> for the two choices of the Lagrangian density <italic>L<inf>m</inf></italic>.

Brazil

Edson Otoniel

Juan M.Z. Pretel

Clésio E. Mota

César O.V. Flores

Victor B.T. Alves

Franciele M. da Silva

White dwarf structure in <italic>f</italic>( <italic>R, T, L<inf>m</inf></italic>) gravity: Beyond the Chandrasekhar mass limit

A nonzero neutrino magnetic moment arises already in the minimally extended Standard Model with right-handed massive Dirac neutrinos. The well-known consequence of the neutrino magnetic moment is the phenomenon of neutrino spin oscillations in a magnetic field. It can manifest itself not only as a lack in the flux of active cosmic neutrinos arriving on Earth but also as characteristic features in low-energy neutrino elastic scattering processes. Following our approach developed earlier, in this work we study the influence of arbitrary spin-flavor state of incoming neutrino on low-energy neutrino scattering off different particles in a detector. We demonstrate that superposition of left- and right-handed helicity neutrino states gives rise to an azimuthal asymmetry in the angular distribution of the recoil momenta. We present numerical calculations for elastic neutrino scattering on electrons, protons and 40Ar and 132Xe nuclei, demonstrating the azimuthal-asymmetry effect. Our results indicate the unique potential of directional neutrino detection to observe the neutrino spin oscillations.

Russia

Konstantin A. Kouzakov

Fedor M. Lazarev

Alexander I. Studenikin

The potential of directional neutrino detection to observe neutrino spin oscillations

We consider the resummation of large logarithmic corrections arising in the two-particle limit at next-to-next-to-leading logarithmic (NNLL) accuracy for the heavy-jet mass and <italic>C</italic>-parameter distributions in the decay of a Higgs boson to quarks and gluons: <math altimg='si2.svg'><mrow><mi>H</mi><mo>&#8594;</mo><mi>b</mi><mover accent='true'><mi>b</mi><mo>&#175;</mo></mover></mrow></math>, <math altimg='si3.svg'><mrow><mi>H</mi><mo>&#8594;</mo><mi>c</mi><mover accent='true'><mi>c</mi><mo>&#175;</mo></mover></mrow></math>, and <italic>H</italic>&#8239;&#8594;&#8239; <italic>gg</italic>. We demonstrate how the matched NNLO+NNLL results clarify the relative contributions of key hadronic Higgs-decay channels ( <math altimg='si2.svg'><mrow><mi>H</mi><mo>&#8594;</mo><mi>b</mi><mover accent='true'><mi>b</mi><mo>&#175;</mo></mover></mrow></math>, <math altimg='si3.svg'><mrow><mi>H</mi><mo>&#8594;</mo><mi>c</mi><mover accent='true'><mi>c</mi><mo>&#175;</mo></mover></mrow></math>, <italic>H</italic>&#8239;&#8594;&#8239; <italic>gg</italic>) yielding reduced uncertainties for both event-shape observables &#8211; especially for heavy-jet mass &#8211; while revealing substantial effects that shift the <italic>C</italic>-parameter peak in gluonic decays.

Elliot Fox

Switzerland

Aude Gehrmann-De Ridder

Thomas Gehrmann

Nigel Glover

Matteo Marcoli

Christian T. Preuss

NNLO+NNLL predictions for heavy-jet mass and <italic>C</italic>-parameter in Higgs decays to quarks and gluons

We investigate the decay modes of a CP-even scalar boson <italic>&#981;</italic> that mixes with the Standard Model Higgs boson, focusing on the mass range between 2&#8239;GeV and 2 <italic>m<inf>&#964;</inf></italic>. Starting from a higher-order perturbative calculation of the inclusive decays <italic>&#981;</italic>&#8239;&#8594;&#8239; <italic>gg</italic> and <math altimg='si3.svg'><mrow><mi>&#981;</mi><mo>&#8594;</mo><mi>s</mi><mover accent='true'><mi>s</mi><mo>&#175;</mo></mover></mrow></math>, we employ a hadronisation model to obtain predictions for individual hadronic final states. Our hadronisation model is based on the Herwig cluster model, but incorporates various conservation laws to determine the allowed final states and their respective weights. The model includes two tunable parameters, which we determine using dispersion relation results at <math altimg='si4.svg'><mrow><msub><mi>m</mi><mi>&#981;</mi></msub><mo linebreak='goodbreak'>=</mo><mn>2</mn></mrow></math> GeV, enabling extrapolation to higher masses. Our predictions show that two-particle hadronic final states like <math altimg='si5.svg'><mrow><msup><mi>&#960;</mi><mo>+</mo></msup><msup><mi>&#960;</mi><mo>&#8722;</mo></msup></mrow></math> and <math altimg='si6.svg'><mrow><msup><mi>K</mi><mo>+</mo></msup><msup><mi>K</mi><mo>&#8722;</mo></msup></mrow></math> dominate over <math altimg='si7.svg'><mrow><msup><mi>&#956;</mi><mo>+</mo></msup><msup><mi>&#956;</mi><mo>&#8722;</mo></msup></mrow></math> for <italic>m<inf>&#981;</inf></italic> near 2&#8239;GeV, suggesting promising targets for future experimental searches.

Stefan Gieseke

Felix Kahlhoefer

Henry Seebach

Branching ratios for Higgs-mixed scalars at the GeV scale from hadronisation models with conservation laws