In a previous paper [Flores-Baez et al., <a href="http://dx.doi.org/10.1103/PhysRevD.76.096010">Phys. Rev. D 76, 096010 (2007)</a>] we have calculated the radiative corrections to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ρ</mi><mo stretchy="false">→</mo><mi>π</mi><mi>π</mi></math> decays, aiming to estimate the width difference between charged and neutral rho mesons. There, we have used the scalar quantum electrodynamics approximation and considered the convection terms to keep the loop contributions finite in the case of charged rho meson decays. Here we compute the radiative corrections by considering the electromagnetic structure of charged mesons and we also include the full Lorentz structure of the electromagnetic vertices. We reevaluate the width difference of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>ρ</mi><mo>±</mo></msup><mo>−</mo><msup><mi>ρ</mi><mn>0</mn></msup></math> vector mesons and calculate the structure-dependent contributions to final state radiation terms in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup><mo stretchy="false">→</mo><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup></math> cross section. Both effects are important inputs for evaluating the isospin breaking corrections in the dominant hadronic vacuum polarization contributions to the muon <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>g</mi><mo>−</mo><mn>2</mn></math> when using <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi></math> lepton data.

Mexico

F.V. Flores-Baez

G. López Castro

Genaro Toledo

Beyond scalar QED radiative corrections: The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>ρ</mi><mo>±</mo></msup><mo>−</mo><msup><mi>ρ</mi><mn>0</mn></msup></math> width difference, final state radiation corrections, and their impact on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Δ</mi></math> <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>a</mi><mi>μ</mi><mrow><mi>HVP</mi><mo>,</mo><mi>LO</mi></mrow></msubsup><mo stretchy="false">[</mo><mi>τ</mi><mo stretchy="false">]</mo></math>

We investigate the effective potential and the string tension for the spatial Wilson loop in hot dense quark-gluon plasma with two types of anisotropy, i.e., external magnetic field and spatial anisotropy, employing a holographic approach for the heavy quark model. In this approach, the string is extended in the fifth, holographic direction and has a turning point either on a dynamical wall (DW) configuration or on the horizon configuration in the fifth direction. We obtain the magnetic catalysis behavior for a phase transition between DW and horizon configuration of the string. The structure of the phase diagram does not depend on the boundary conditions choice for the dilaton field. Inclusion of the external magnetic field and spatial anisotropy enhance the string tension in the horizon configuration, namely drag force. For the spatially isotropic case <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ν</mi><mo>=</mo><mn>1</mn></math> at different magnetic field values, the string tension is proportional to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>T</mi><mn>2</mn></msup></math> and is qualitatively consistent with lattice results. However, for the anisotropic case, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ν</mi><mo>=</mo><mn>4.5</mn></math>, it deviates from the quadratic term.

Russia

Irina Ya. Aref’eva

Iran

Ali Hajilou

Kristina Rannu

Pavel Slepov

Spatial Wilson loops and energy loss for heavy quarks in a magnetized holographic QCD model

The scattering of dark matter (DM) particles within the Sun’s hot plasma can lead to the acceleration of dark matter, producing a high-energy solar-reflected DM flux detectable in ground-based experiments. In the vector portal model, the dark matter has a sub-MeV-scale mass, and interactions between the dark matter and Standard Model particles are mediated by a hidden vector field—referred to as a dark photon—which kinetically mixes with the conventional photon through a small mixing angle. Furthermore, the solar plasma generates intense magnetic fields. Due to the photon-dark photon mixing, this simultaneously sources a “dark magnetic field.” For sufficiently low dark photon masses, this dark magnetic field is capable of deflecting dark matter particles traversing the Sun. We found that if the dark magnetic force is sufficiently strong, the dark magnetic field becomes a wall, preventing the dark matter particles from reaching the deep core region, suppressing their reflected flux. This scenario corrects the sensitivity of the solar-reflected dark matter detection, offering critical insights for ground-based experiments aiming to probe dark matter.

China

Haoming Nie

Solar reflected dark matter under the influence of a dark magnetic field

Thallium-doped sodium iodide (NaI(Tl)) scintillation detectors play an important role in the field of direct dark matter (DM) searches. The DAMA/LIBRA experiment stands out for its reported observation of an annually modulating DM-like signal, which is in direct contrast with other results. To accurately calibrate the energies of nuclear recoil signals with electron recoils, precise measurements of the quenching factor of the NaI(Tl) crystals are essential, as the two processes have different scintillation light yield. In this article, we present results of a systematic study carried out by the COSINUS collaboration and Duke University to measure the quenching factor of sodium (Na) recoils as a function of nuclear recoil energy and for differing Thallium (Tl) dopant concentrations in the bulk crystal. Five ultrapure NaI(Tl) crystals, manufactured by the Shanghai Institute for Ceramics, were irradiated with a quasi-monoenergetic neutron beam at the Triangle Universities Nuclear Laboratory, North Carolina, USA. The quenching factor for nuclear recoils off Na with low energies of 6–26keV $$_{\text {nr}}$$ was extracted for all crystals, using two proportional calibration schemas with lines from a $$^{241}$$ Am source and a $$^{133}$$ Ba source. A Tl-dependence could be deduced in both cases, where a lower Tl concentration leads to smaller observed QF.

Germany

G. Angloher

M. Bharadwaj

Austria

A. Böhmer

M. Cababie

Italy

I. Colantoni

I. Dafinei

N. Marco

C. Dittmar

L. Einfalt

F. Ferella

F. Ferroni

S. Fichtinger

A. Filipponi

T. Frank

M. Friedl

M. Gapp

L. Gai

Z. Ge

Finland

M. Heikinheimo

M. Hughes

K. Huitu

M. Kellermann

R. Maji

M. Mancuso

L. Pagnanini

F. Petricca

S. Pirro

F. Pröbst

G. Profeta

A. Puiu

F. Reindl

K. Schäffner

J. Schieck

P. Schreiner

C. Schwertner

K. Shera

M. Stahlberg

A. Stendahl

Canada

M. Stukel

C. Tresca

Switzerland

F. Wagner

S. Yue

V. Zema

Y. Zhu

United States

P. Barbeau

S. Hedges

C. Awe

J. Runge

T. Johnson

D. Markoff

P. An

C. Prior

A. Bracho

S. Alawabdeh

Quenching factors for Na recoils as a function of Tl dopant concentrations in NaI(Tl) crystals

The paper is devoted to the three-loop renormalization of the effective action for a two-dimensional non-linear sigma model using the background field method and a cutoff regularization in the coordinate representation. The coefficients of the renormalization constant and the necessary auxiliary vertices are found, as well as the asymptotic expansions of all three-loop diagrams, and their dependence on the type of regularizing function. A comparison is also made with the standard case of cutoff in the momentum representation.

P. Akacevich

A. Ivanov

I. Korenev

Three-loop singularity structure for a non-linear sigma model

We explore potential quantum gravity signatures by studying periodic orbits and their GW emissions around a novel regular black hole (BH) featuring a Minkowski core. Using a rational number $\textit{q}$, periodic orbits are classified, revealing that the deviation parameter $$\alpha _0$$ reshapes the bound-orbit region while preserving characteristic “zoom-whirl” structures. Numerical kludge waveforms reveal detectable phase shifts and amplitude modulations induced by quantum gravity effects with radiation reaction breaking orbital periodicity. Faithfulness analysis demonstrates that larger $$\alpha _{0}$$ and $\textit{q}$ enhance distinguishability from the Schwarzschild case, and a comparison with Hayward and quantum Oppenheimer–Snyder BHs shows their similar large-scale behaviors yield macroscopically indistinguishable orbits and waveforms.

Huajie Gong

Sheng Long

Xi-Jing Wang

Zhongwu Xia

Jian-Pin Wu

Qiyuan Pan

Gravitational waveforms from periodic orbits around a novel regular black hole

We present a systematic framework for constructing exactly-solvable lattice models of symmetry-enriched topological (SET) phases based on an enlarged version of the string-net model. We also gauge the global symmetries of our SET models to obtain string-net models of pure topological phases. Without invoking externally imposed onsite symmetry actions, our approach promotes the string-net model of a pure topological order, specified by an input unitary fusion category $$ \mathcal{F} $$ , to an SET model, specified by a multifusion category together with a set of isomorphisms. Two complementary construction strategies are developed in the main text: (i) promotion via outer automorphisms of $$ \mathcal{F} $$ and (ii) promotion via the Frobenius algebras of $$ \mathcal{F} $$ . The global symmetries derived via these two strategies are intrinsic to topological phases and are thus termed blood symmetries, as opposed to adopted symmetries, which can be arbitrarily imposed on topological phases. We propose the concept of symmetry-gauging family of topological phases, which are related by gauging their blood symmetries. With our approach, we construct the first explicit lattice realization of a nonabelian-symmetry-enriched topological phase — the $\textit{S}$ symmetry-enriched $\textit{ℤ}$ × $\textit{ℤ}$ quantum-double phase. The approach further reveals the role of local excitations in SET phases and establishes their symmetry constraints.

Nianrui Fu

Yu Zhao

Yidun Wan

Symmetry-enriched topological phases and their gauging: a string-net model realization

We construct a pseudo-Newtonian potential (PNP) corresponding to a rotating black hole solution in a modified gravity (MGR) framework using a metric-based prescription. The motivation is to enable realistic accretion disk studies in MGR, where full relativistic MHD simulations remain computationally prohibitive. Effective potentials and the underlying Newtonian-like forces are derived for both massive and massless particles in the equatorial plane, relevant for disk dynamics. The reliability of the PNP is tested by comparing key orbital properties – marginally stable, marginally bound, photon orbits and energies at marginally stable orbit radii – with exact MGR predictions. The PNP reproduces the marginally stable and photon orbits exactly, while marginally bound orbits and specific energies deviate by less than about 7–10%. The influence of the MGR parameter on particle dynamics and effective potentials is analyzed, revealing non-trivial departures from simple Newtonian intuition. The study demonstrates that the proposed PNP accurately captures essential spatial properties of MGR spacetime and provides an efficient, physically consistent tool for investigating accretion phenomena and strong-gravity astrophysics beyond general relativity.

India

Sriraj Chandra

Banibrata Mukhopadhyay

Pseudo-Newtonian potential for accretion disks in a modified gravity spacetime around the black hole and underlying properties

It is a common lore that in thermal leptogenesis within the type-I seesaw framework and a hierarchical spectrum of heavy right-handed neutrinos (RHNs), the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math>-violating, out-of-equilibrium decay of the lightest RHN (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mn>1</mn></msub></math>) is the only relevant source of the final <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo>−</mo><mi>L</mi></math> asymmetry, since any asymmetry produced by the heavier RHNs is expected to be erased by subsequent <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mn>1</mn></msub></math>-mediated washout processes. In this work, we revisit this assumption by solving the density-matrix equations, including decay, inverse decay, and relevant scattering processes, and by fully accounting for flavor-projection effects induced by the Yukawa coupling structure. We show that the asymmetries generated by the heavier RHNs (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mn>2</mn></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mn>3</mn></msub></math>) generally possess components that are misaligned in flavor space with respect to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mn>1</mn></msub></math>, resulting in a partially protected contribution that survives the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mn>1</mn></msub></math> washout. Unlike the conventional picture of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mn>2</mn></msub></math>-dominated leptogenesis, this memory effect arises even when <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mn>1</mn></msub></math> remains dynamically relevant and cannot be captured within the classical Boltzmann framework. Furthermore, imposing consistency with low-energy neutrino mass and mixing data, we find that at most one RHN can lie in the weak washout regime, which naturally divides the parameter space into four distinct dynamical regimes. We systematically quantify the memory effect in each regime and demonstrate that it can significantly modify the final <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo>−</mo><mi>L</mi></math> asymmetry. We find that including projection effects can indeed extend the viable parameter space into the sensitivity range of neutrinoless double beta decay experiments.

Partha Kumar Paul

Narendra Sahu

Shashwat Sharma

Does thermal leptogenesis in a canonical seesaw scenario rely on initial memory?

We investigate the emergence of spacetime geometry within the AdS/CFT correspondence by explicitly incorporating quantum coherence effects arising from finite coherent superpositions of closed-string modes forming mesoscopic quantum D-branes. We show that the stage at which quantum coherence is suppressed relative to the construction of the emergent geometry significantly influences the resulting spacetime structure. Suppressing coherence prior to constructing the effective geometric description yields a purely classical Anti-de Sitter (AdS) geometry, whereas constructing the geometry from a coherent state and only subsequently suppressing interference leads to controlled quantum corrections of order $$O(M^{-2})$$ to the AdS background. We further demonstrate that both microscopic coherence between string modes and mesoscopic coherence among D-branes distinctly shape the resulting spacetime structure, introducing measurable quantum deviations from classical geometry. Our results provide critical insights into how quantum coherence may underpin the emergence of classical gravity and offer new directions for studying quantum-gravitational phenomena within holographic frameworks.

Andrei Patrascu

Quantum corrections to the AdS bulk from a semiclassical description of D-branes