We propose a novel observable for the precision measurements of a wide class of near-threshold dimer states: the short-range production rate of a dimer–spectator two-body system, composed of the given near-threshold state and one of its constituents. Within the framework of nonrelativistic effective field theory, these production rates exhibit characteristic line shapes for the specific partial wave and reach a model-independent minimum. This feature enables a precise extraction of their masses from experimental data, provided that the line shape can be resolved with sufficient accuracy. Applying this novel method to both the <math altimg='si5.svg'><mrow><msub><mi>T</mi><mrow><mi>b</mi><mover accent='true'><mi>b</mi><mo>&#175;</mo></mover><mn>1</mn></mrow></msub><mrow><mo>(</mo><mn>10610</mn><mo>)</mo></mrow><mi>B</mi></mrow></math> and <math altimg='si6.svg'><mrow><msub><mi>T</mi><mrow><mi>b</mi><mover accent='true'><mi>b</mi><mo>&#175;</mo></mover><mn>1</mn></mrow></msub><mrow><mo>(</mo><mn>10650</mn><mo>)</mo></mrow><msup><mi>B</mi><mo>*</mo></msup></mrow></math> systems allows for a precise determination of the binding energy <italic>&#948;</italic> of the <math altimg='si7.svg'><mrow><msub><mi>T</mi><mrow><mi>b</mi><mover accent='true'><mi>b</mi><mo>&#175;</mo></mover><mn>1</mn></mrow></msub><mrow><mo>(</mo><mn>10610</mn><mo>)</mo></mrow></mrow></math> and <math altimg='si8.svg'><mrow><msub><mi>T</mi><mrow><mi>b</mi><mover accent='true'><mi>b</mi><mo>&#175;</mo></mover><mn>1</mn></mrow></msub><mrow><mo>(</mo><mn>10650</mn><mo>)</mo></mrow></mrow></math> via the relation of <math altimg='si9.svg'><mrow><mi>&#948;</mi><mo linebreak='goodbreak'>=</mo><mo>&#8722;</mo><msubsup><mi>E</mi><mrow><mtext>dip</mtext></mrow><mtext>exp</mtext></msubsup><mo linebreak='goodbreak'>/</mo><mrow><mn>0.1983</mn></mrow></mrow></math> once the respective dip position <math altimg='si10.svg'><msubsup><mi>E</mi><mrow><mtext>dip</mtext></mrow><mtext>exp</mtext></msubsup></math> is experimentally identified.

China

Germany

Yong-Hui Lin

Hans-Werner Hammer

Ulf-G. Meißner

Model-independent mass determination of near-threshold states from short-range production

One or two negative mass singularities are found to occur in static inhomogeneous spatially closed solutions to the Einstein equations. The singularities produce a positive Komar mass, and this decreases the size of the cosmological constant relative to normal matter. The energy density of a perfect fluid vanishes at the singularities and is finite elsewhere. Numerical examples of these static solutions are provided, and their stability properties are found to be similar to the Einstein static universe. In an expanding universe, the effect of the singularities is to push the acceleration towards more positive values. Given the sentiment that naked singularities are to be avoided, we review just how benign the negative mass singularity is.

Canada

Bob Holdom

Negative mass singularities mimicking dark energy

The 83Se nucleus was studied in the context of shape coexistence employing a 82Se(d,p) 83Se reaction performed in inverse kinematics with the GALILEO-II + SPIDER setup to reach the desired selectivity on the reaction channel of interest via <italic>&#947;</italic>-particle coincidences. The lifetimes of the 1/2 <math altimg='si1.svg'><msup><mrow /><mo>+</mo></msup></math> 540-keV and 3/2 <math altimg='si15.svg'><msubsup><mrow /><mn>3</mn><mo>+</mo></msubsup></math> 1100-keV low-lying intruder states of 83Se were measured for the first time by employing the Recoil Distance Doppler Shift and the Doppler Shift Attenuation Method. The deduced transition probabilities, together with the mixing ratios obtained from a separate neutron-capture experiment performed at ILL with the FIPPS array, are compared and discussed in the framework of shell-model calculations performed with the PFSDG-U Hamiltonian. Large transition probabilities of hundreds of <italic>e</italic> 2 <italic>fm</italic> 4 were found for the <italic>E</italic>2 decays of the states built on top of the intruders, pointing to the development of quadrupole collectivity and large deformation in the proximity of <math altimg='si14.svg'><mrow><mi>N</mi><mo linebreak='goodbreak'>=</mo><mn>50</mn></mrow></math> shell closure.

Italy

J. Pellumaj

A. Gottardo

A. Goasduff

J.J. Valiente-Dobón

F. Conca

France

D.D. Dao

F. Nowacki

A. Poves

G. Benzoni

S. Bottoni

D. Brugnara

S. Capra

M. Cicerchia

Poland

N. Cieplicka-Oryńczak

G. Corbari

F.C.L. Crespi

G. De Angelis

B. Fornal

E. Gamba

A. Gozzelino

J. Ha

Y.H. Kim

U. Köster

S.M. Lenzi

S. Leoni

M. Luciani

T. Marchi

Romania

N. Mǎrginean

R. Mǎrginean

R. Menegazzo

D. Mengoni

C. Michelagnoli

C. Mihai

B. Million

S. Nagorny

A. Nannini

D.R. Napoli

R.M. Pérez-Vidal

S. Pigliapoco

S. Pirro

F. Recchia

D. Reygadas

K. Rezynkina

United States

M. Siciliano

Belgium

M. Sferrazza

A. Turturica

I. Zanon

S. Ziliani

G. Zhang

S. Carturan

M. Loriggiola

Development of deformed intruder structures along the <math altimg='si14.svg'><mrow><mi>N</mi><mo linebreak='goodbreak'>=</mo><mn>50</mn></mrow></math> magic number: Insights from 83Se

Motivated by the continued null results in direct detection, we explore a purely geometric dark matter paradigm. By modeling the quantum information vacuum as a <math altimg='si2.svg'><msup><mi mathvariant='double-struck'>CP</mi><mn>1</mn></msup></math> manifold, we demonstrate that localized topological defects dynamically generate a conserved energy-momentum tensor. Identifying the defect core radius with the physical symmetry-breaking scale ( <italic>r<inf>c</inf></italic>&#8239;&#8771;&#8239;1/ <italic>T<inf>c</inf></italic>), these macroscopic entities acquire a topologically protected mass ( <math altimg='si3.svg'><mrow><msub><mi>M</mi><mrow><mi>g</mi><mi>e</mi><mi>o</mi><mi>m</mi></mrow></msub><mo>&#8771;</mo><mfrac><mrow><mi>&#960;</mi><mi>&#954;</mi><msup><mi>k</mi><mn>2</mn></msup></mrow><mn>2</mn></mfrac><msub><mi>T</mi><mi>c</mi></msub></mrow></math>) and behave dynamically as pressureless dust ( <math altimg='si4.svg'><mrow><mo>&#9001;</mo><mi>w</mi><mo>&#9002;</mo><mo>=</mo><mn>0</mn></mrow></math>). Applying the Kibble-Zurek mechanism to their primordial formation, we derive a Master Geometric Constraint which, remarkably, transforms into a predictive cosmological framework. Assuming a fundamental winding number <math altimg='si5.svg'><mrow><mi>k</mi><mo linebreak='goodbreak'>=</mo><mn>1</mn></mrow></math> and topological stiffness <italic>&#954;</italic>&#8239;&#8776;&#8239;1, the universe dictates a symmetry-breaking temperature of <italic>T<inf>c</inf></italic>&#8239;&#8776;&#8239;2.6&#8239;&#215;&#8239;10 11&#8201;GeV, rigidly fixing the geometric dark matter mass at <italic>M<inf>geom</inf></italic>&#8239;&#8776;&#8239;4.1&#8239;&#215;&#8239;10 11&#8201;GeV. This purely geometric derivation perfectly reproduces the observed relic abundance (&#937; <inf><italic>CDM</italic></inf> <italic>h</italic> 2&#8239;&#8776;&#8239;0.120). Furthermore, this GUT-scale regime naturally explains the absence of direct detection signals and yields an exceptionally diffuse gravitational compactness ( <math altimg='si6.svg'><mrow><mi>C</mi><mo>&#8764;</mo><msup><mn>10</mn><mrow><mo>&#8722;</mo><mn>14</mn></mrow></msup></mrow></math>). Consequently, these geometric defects possess a non-zero tidal deformability, offering a distinct astrophysical signature for future gravitational wave observatories, effectively distinguishing them from primordial black holes.

Thailand

Samak Boonpan

Thermodynamics and relic density of topological defects in quantum information geometry

We propose a cogenesis mechanism that unifies the origin of QCD axion dark matter and the baryon asymmetry of the Universe in the framework of Peccei-Quinn pole inflation. The model integrates the Peccei-Quinn symmetry with the seesaw mechanism for neutrino masses. This allows for spontaneous leptogenesis, which generates the required <math altimg='si7.svg'><mrow><mi>B</mi><mo linebreak='goodbreak'>&#8722;</mo><mi>L</mi></mrow></math> asymmetry around the seesaw scale. The necessary initial axion kinetic misalignment is naturally sourced by a PQ field driving pole inflation. Analysis within the KSVZ axion model demonstrates that achieving simultaneous correct DM abundance and baryon asymmetry limits the axion decay constant to be smaller than about 10 9 GeV. This framework offers a unified solution to four fundamental problems: the strong CP problem, neutrino mass, matter-antimatter asymmetry, and inflation.

South Korea

Eung Jin Chun

Hyun Min Lee

Jun-Ho Song

Peccei-Quinn genesis

We develop the eigen-microstate framework as a new approach to identify criticality in relativistic heavy-ion collisions. We construct the original microstate, defined as the final-state particle fluctuations of a single event. By examining ensembles of such original microstates with and without critical signals, we demonstrate that the corresponding eigen microstate can extract and reveal the dominant critical mode, with the largest eigenvalue serving as a robust order parameter. This framework avoids equilibrium assumptions and is insensitive to non-critical background, and the approach is directly applicable to RHIC Beam Energy Scan data, offering a powerful new tool in the search for the QCD critical point.

Ranran Guo

Jin Wu

Mingmei Xu

Xiaosong Chen

Zhiming Li

Zhengning Yin

Yuanfang Wu

Eigen-microstate signatures of criticality in relativistic heavy-ion collisions

We investigate the emergence and detection of Hawking radiation (HR) in a 1D chiral spin chain model, where the gravitational collapse is simulated by a sudden quantum quench that triggers a horizon-inducing phase transition. While our previous work [33] established that this model mimics black hole (BH) formation conditions even when the Hoop conjecture is seemingly violated, we here focus on the resulting stationary radiation spectrum and its detectability. By mapping the spin chain dynamics to a Dirac fermion in a curved <math altimg='si9.svg'><mrow><mo>(</mo><mn>1</mn><mo linebreak='goodbreak'>+</mo><mn>1</mn><mo>)</mo></mrow></math>-dimensional spacetime, we analyze the radiation using two complementary approaches: field-theoretic modes and operational quantum sensors. First, using localized Gaussian wave packets to model realistic detectors, we find that the radiation spectrum exhibits deviations from the ideal Planckian form, while retaining robust Poissonian statistics that signal the loss of formation-scale information. Second, we introduce a qubit coupled globally to the chiral spin chain. Rather than acting as a localized point detector (which would break translational invariance), the qubit couples to the collective chiral excitations of the analogue spacetime, functioning as a global quantum sensor. We demonstrate that the decoherence dynamics of this macroscopic probe faithfully encode the thermal nature of the HR in the weak-coupling limit, while strong-coupling dynamics reveal non-Markovian memory effects driven by the horizon. These results provide a clear operational protocol for distinguishing genuine analog HR from environmental noise in quantum simulation platforms.

India

Nitesh Jaiswal

S. Shankaranarayanan

Emergent Hawking radiation and quantum sensing in a quenched chiral spin chain

We discuss some entanglement features associated with cubic non-Gaussian perturbations in single-field inflationary scenarios. We adopt standard momentum-space techniques to show how multipartite entanglement arises for inflationary perturbation modes, focusing on the dynamics of the comoving curvature perturbation. In particular, we quantify entanglement generation via the recently proposed Entanglement Distance, which introduces a geometric interpretation of quantum correlations in terms of the Fubini-Study metric. In the continuum limit, we show that the Entanglement Distance arising from displacement transformations is proportional to the total number of excitations in the quantum state for cubic perturbations, thus providing an upper bound on the von Neumann entanglement entropy of any reduced state compatible with such excitations. Within the interaction picture, we further observe that the quantum correlations arising from cubic gravitational interactions are typically much larger than the standard squeezing contribution, in agreement with previous studies focusing on von Neumann entropy generation across the Hubble horizon. We further show how the inflationary parameters affect the total amount of such correlations, highlighting in particular their dependence on the inflationary energy scales and the number of e-foldings during slow-roll.

Alessio Belfiglio

Roberto Franzosi

Kazakhstan

Orlando Luongo

Multipartite entanglement features of primordial non-Gaussianities

This work studies light propagation near slowly rotating traversable wormholes supported by a quantum-inspired matter source. The model is based on the Dymnikova density profile, viewed as a gravitational analogue of the Schwinger mechanism, which yields a smooth, non-singular core. Quantum effects are included through the generalized uncertainty principle (GUP), introducing a minimal length scale while preserving regularity. Within a stationary and axisymmetric framework, we construct rotating wormhole solutions sustained by the GUP-corrected Dymnikova-Schwinger profile. The geometry satisfies key conditions such as asymptotic flatness and the flare-out requirement, and incorporates rotational features like frame dragging. We then examine photon motion via null geodesics. Both rotation and quantum corrections modify the photon sphere structure, with rotation producing a splitting between co-rotating and counter-rotating trajectories. This results in small asymmetries in photon paths and the shadow. These results provide a novel and consistent framework to probe quantum-gravity imprints in strong-field optics.

Azerbaijan

South Africa

A. Errehymy

Morocco

Y. Khedif

M. Daoud

Uzbekistan

B. Turimov

Saudi Arabia

Meraj Ali Khan

S. Usanov

Dymnikova-Schwinger quantum-corrected slowly rotating wormholes: Photon and spinning particle dynamics

We perform a model-independent reconstruction of the cosmic expansion history using Gaussian Process regression, investigating how the smoothness properties of covariance kernels influence the inferred Hubble parameter. Using 32 cosmic chronometer measurements, we reconstruct <italic>H</italic>( <italic>z</italic>) with the Mat&#233;rn 3/2, 5/2, 7/2, 9/2, and Squared Exponential kernels, which form a well-defined hierarchy of differentiability. Across this hierarchy, we observe a systematic and monotonic trend in which increasing kernel smoothness is associated with progressively lower reconstructed values of the present-day Hubble constant <italic>H</italic> <inf>0</inf>, accompanied by reduced statistical uncertainties. Rather than indicating a statistical preference for a specific kernel, this behaviour reflects the sensitivity of non-parametric reconstructions to the assumed smoothness prior encoded in the covariance function. The same ordering is reflected in descriptive goodness-of-fit statistics and remains stable when incorporating recent DESI DR2 BAO measurements and performing jackknife resampling tests, demonstrating robustness against individual data points and dataset variations. Additional analysis of derivative reconstructions shows that differences in kernel differentiability propagate into the local slope of the expansion history, providing a consistent interpretation of the observed ordering in <italic>H</italic> <inf>0</inf>. Our results highlight that kernel smoothness plays an important role in Gaussian Process reconstructions and should be carefully accounted for when interpreting non-parametric cosmological inferences.

Afaq Maqsood

Derivative hierarchy as the origin of kernel-dependent trends in Gaussian process reconstructions of the hubble parameter