We present initial results on the detection of nuclear recoils in lithium fluoride (LiF) through the fluorescence of color centers created by particle interactions in the crystal lattice. Using light-sheet fluorescence microscopy, we image nuclear recoil tracks from both fast and thermal neutron interactions deep within a cubic-centimeter-scale sample. Automated three-dimensional feature extraction based on machine-learning tools enables the identification and classification of individual events. We observe that the fluorescence response of LiF to gamma irradiation is strongly suppressed, by a factor of 30–50 compared to neutron exposure, demonstrating intrinsic insensitivity to electromagnetic backgrounds. The observed and simulated event characteristics are consistent, including their number, size, and topology. These results establish the feasibility of LiF as a scalable detection medium for rare nuclear-recoil events and constitute a first step toward 10–1000 g scale detectors with single-event sensitivity for applications in reactor-neutrino detection, neutron spectroscopy, and dark matter searches.

Switzerland

Gabriela Araujo

Laura Baudis

United States

Nathaniel Bowden

Jordan Chapman

Anna Erickson

Mariano Guerrero Perez

Adam Hecht

Samuel Hedges

Patrick Huber

Vsevolod Ivanov

Igor Jovanovic

Giti Khodaparast

Brenden Magill

Jose Mateos

Maverick Morrison

Nicholas Smith

Slovenia

Patrick Stengel

Stuti Surani

Nikita Vladimirov

Keegan Walkup

Christian Wittweg

Xianyi Zhang

Nuclear recoil detection with color centers in bulk lithium fluoride

The internal structure of the exotic $$P_c$$ and $$P_{cs}$$ pentaquarks remains an open question. To address this, we demonstrate that pion emission serves as a sensitive probe by calculating its properties within a molecular scenario using the chiral quark model and coupled-channel effects. Our results reveal a strong dependence of the decay widths on the internal structure and spatial wave functions within the molecular framework. Notably, the relative ratios of the decay widths among different spin-parity assignments are found to be much more robust against model parameter variations than the absolute values, providing a clean discriminator for quantum numbers. We therefore expect this study to stimulate experimental measurements of these decays, which are crucial for determining the nature of these states and guiding the search for further molecular partners.

China

Li-Cheng Sheng

Yu-Jie Tang

Yu-Xin Wan

Rui Chen

Dian-Yong Chen

Exploring pion emission properties of (strange) hidden-charm molecular pentaquarks in a chiral quark model

In the present work, we numerically investigate the horizon structure of the Kerr–Sen black holes in anti-de Sitter (AdS) spacetime. Further, we investigate the phase transitions and critical phenomena in Kerr–Sen–AdS black holes at the critical points. Such black holes are characterized by its mass ($\textit{M}$), the dilaton charge ($\textit{Q}$), and the negative cosmological constant, $$\Lambda (<0)$$ . We define a dimensionless parameter $$\epsilon =\bar{J}/{\bar{Q}^2}$$ and express the mass, temperature, volume, and Gibbs free energy in terms of $$\epsilon $$ and its polynomials. Moreover, we numerically fit the data for the critical points and find that in the appropriate limit, the expressions for critical points would correspond to the respective critical points of the Kerr–AdS black hole thermodynamics. Such a study involves a systematic analysis of temperature, Gibbs free energy, and volume in the extended phase space. We provide an analytical verification of the nature of the phase transitions at the critical points by introducing the Ehrenfest equations. We find that the Ehrenfest equations are satisfied in accordance with the phase behaviour. We also check that all three quantities, e.g., the specific heat at constant pressure, $$C_P$$ , the volume expansion coefficient, $$\alpha $$ , and the isothermal compressibility, $$\kappa _T$$ , diverge at the critical points. We find the $\textit{Prigogine}$-$\textit{Defay}$ ratio using the expressions of $$C_P$$ , $$\alpha $$ , and $$\kappa _T$$ , and find that it identically equals unity. Hence, the phase transition behavior of the Kerr–Sen–AdS black holes at their critical points is of second order. In addition, we propose investigating the energy extraction process via the Penrose process by deriving work efficiency. Later, we calculate the speed of sound and adiabatic compressibility for the rotating Kerr–Sen–AdS black holes. Finally, on a specific note, we calculate the thermodynamic quantities of the boundary conformal field theory (CFT) dual to the extended phase space.

India

Md Ali

Arindam Mondal

South Africa

Sushant Ghosh

The extended phase space thermodynamics and Ehrenfest scheme for the Kerr–Sen AdS black holes

A parametric simulation tool for pixel sensors is presented. A realistic pixel response is simulated purely based on measurement input, without requiring detailed knowledge of the underlying manufacturing process. As such, it provides an efficient alternative to the use of Technology Computer-Aided Design simulations, which typically depend on proprietary process information. Due to its parametric approach, the package is fast and thus particularly useful for larger detector systems and high hit rate environments. This work presents measurements, simulation and its validation for the MALTA2 sensor. It is a small collection electrode monolithic active pixel sensor produced in the Tower 180 nm complementary metal-oxide-semiconductor imaging process. Modifications to the sensor’s periphery, mainly in the hit merger, are studied in order to optimize the performance for tracking and calorimetry. This optimization is of special interest as part of the MALTA3 sensor redesign in the 65 nm Tower Partners Semiconductor Co. process.

Germany

Dumitru Berlea

Lucian Fasselt

Prafulla Behera

United Kingdom

Daniela Bortoletto

Craig Buttar

Theertha Chembakan

Valerio Dao

Ganapati Dash

Sebastian Haberl

Tomohiro Inada

Türkiye

Fuat Isik

Cigdem Issever

Xuan Li

Long Li

Heinz Pernegger

Petra Riedler

Walter Snoeys

Carlos Sánchez

Anna Swoboda

Ilkay Cakir

Milou Rijnbach

Anusree Vijay

Julian Weick

Steven Worm

Design optimization of MAPS-based detectors using a data-driven fast simulation approach

In this paper we explore the potential of Ultra-peripheral Collisions at the LHC to investigate new physics, focusing on the production of new charged vector bosons $${V}^{\pm }$$ that decay into heavy neutral leptons $$N_{L}$$ in the context of the Vector Scotogenic Model. We show that the ATLAS experiment, searching for dilepton+met final states via UPCs of lead ions, can directly probe the existence of new charged vector bosons in the 5 GeV $$<M_{V^{\pm }}, M_{N_L}<$$ 105 GeV mass range. Our analysis identifies regions in the parameter space where the signal can be distinguished from the background with high statistical significance. Within this mass range, ATLAS can exclude at 95% CL specific ( $${M}_{{V}^{\pm }}$$ , $${M}_{{N}_{L}}$$ ) mass scenarios such as (30 GeV, 20 GeV), (30 GeV, 10 GeV) and (20 GeV, 10 GeV). In a discovery scenario, ATLAS could reach a significance of 5 $$\sigma $$ for (20 GeV, 10 GeV). In addition, we show that HL-LHC with proton–proton UPCs could explore higher mass ranges, specifically 100 GeV $$< M_{V^{\pm }}, M_{N_L}<$$ 350 GeV. We find that the HL-LHC can exclude this mass range with 95% CL, covering a larger parameter space than previous SUSY searches, and most scenarios can achieve a discovery significance of 5 $$\sigma $$ .

Chile

Y. Oviedo-Torres

Sebastian Tapia

J. Zamora-Saa

Probing the existence of a new charged vector boson decaying into heavy neutral leptons using ultra-peripheral heavy ion collisions at ATLAS

We derive the complete first post-Newtonian (1PN) Lagrangian and corresponding equations of motion for the relativistic $\textit{N}$-body system in Scalar-Tensor-Fourth-Order Gravity (STFOG), including the Non-Commutative Spectral Geometry (NCSG) sector as a special case. In the regime $$\Phi \sim \Psi $$ ( $$\gamma \sim 1$$ ), the linearized fourth-order field equations are solved in the Standard Post-Newtonian gauge, and the variational Lagrangian is built directly from the point-particle action. The resulting dynamics is governed by three Yukawa functions $$\zeta $$ , $$\mathcal {W}$$ and $$\Xi $$ , which encode the scalar, gravitomagnetic and three-body sectors and depend on the effective masses $$(m_R,m_Y,m_\phi )$$ of the additional propagating modes. In this context, we show that the nonlinear metric component $$g_{00}$$ plays no role at 1PN level. The 1PN orbital motion of the above extended theories is thus obtained in closed form, and the Einstein–Infeld–Hoffmann equations are recovered in the corresponding general-relativistic limit. The formalism provides a common framework for relativistic celestial mechanics and applies to Solar-System dynamics, binary pulsars such as PSR J0737–3039, Galactic-center stellar orbits, and triple systems.

Italy

Antonio Tedesco

Post-Newtonian N-body dynamics in extended theories of gravity

We perform a systematic investigation of the interactions between heavy-strange and fully-heavy mesons, specifically the $$B_s^{(*)} D_s^{(*)}$$ , $$B_s^{(*)} B_c^{(*)}$$ , and $$D_s^{(*)} B_c^{(*)}$$ systems, to search for possible hadronic molecular states. By employing the coupled-channel unitary approach within the extended local hidden gauge formalism, we evaluate the interaction potentials driven by the exchange of vector mesons. The Bethe–Salpeter equation with the on-shell approximation is solved to search for poles in the complex energy plane across the pseudoscalar–pseudoscalar ($\textit{PP}$), pseudoscalar–vector ($\textit{PV}$), and vector–vector ($\textit{VV}$) sectors. We account for anomalous parity constraints in the $\textit{PV}$ sector and spin-dependent contact interactions in the $\textit{VV}$ sector. Our analysis reveals several dynamically generated bound states and resonances. The robustness of these predictions is confirmed through a systematic scan of the regularization cutoff, revealing monotonic pole trajectories. We extract their pole positions, decay widths, binding energies, coupling constants, scattering lengths, effective ranges, and molecular probabilities. Furthermore, we characterize the spatial extent of the generated states relative to their constituents to qualify the hadronic molecular interpretation. The predicted states serve as excellent candidates for strange exotic hadrons to be searched for in future experiments.

Mexico

Sara Rahmani

Dynamical generation of strange molecular states via vector meson exchange

We investigate the thermodynamic, optical, and dynamical properties of Reissner–Nordström–de Sitter black holes in a noncommutative spacetime endowed with a fundamental minimal length scale $$\Theta $$ . Working within a consistent two-horizon framework, we formulate an effective first law of thermodynamics and introduce an entanglement entropy that captures correlation effects between the event and cosmological horizons. Imposing the lukewarm condition, under which both horizons share a common temperature, uniquely fixes the entropy correction and yields closed-form expressions for the temperature, pressure, and electric potential. An analysis of the heat capacity, entropy, Helmholtz free energy, and pressure reveals a noncommutativity-induced second-order phase transition, highlighting the crucial role of short-distance structure in the critical behavior of the system. On the optical side, we examine photon motion and weak gravitational lensing in this geometry. We show that noncommutativity deforms the photon effective potential and shifts the critical impact parameter separating capture from scattering. Using the Gauss–Bonnet method, we derive an analytical expression for the weak deflection angle and demonstrate how charge and the minimal length scale modify the optical response in the presence of a cosmological constant. Finally, we establish a direct link between geometry and dynamics by analyzing the Lyapunov exponent of circular photon orbits and the imaginary part of the quasinormal mode frequencies. We show that the black hole parameters leave distinct and systematic imprints on both orbital instability and damping: increasing the mass suppresses the instability and leads to longer-lived modes, charge enhances both the divergence of null geodesics and the decay rate, the cosmological constant slightly reduces damping, and noncommutativity amplifies the instability and accelerates relaxation.

Thailand

Phongsakorn Sereewat

David Senjaya

Piyabut Burikham

Thermodynamics and geometrical optics of Reissner–Nordström–de Sitter black holes in noncommutative geometry

Motivated by the recent observation of the pseudoscalar toponium $${\eta }_{t}$$ at the LHC and by the ongoing interest in its properties, we phenomenologically investigate the $${\eta }_{t}$$ $${\rightarrow }$$ $$W^{+}W^{-}$$ process, one of the characteristic decays of toponium $${\eta }_{t}$$ . The branching ratio for the $${\eta }_{t}$$ $${\rightarrow }$$ $$W^{+}W^{-}$$ decay is estimated with two scenarios of the decay constant $$f_{{\eta }_{t}}$$ . It is found that tens of dilepton events from the cascade decays, $${\eta }_{t}$$ $${\rightarrow }$$ $$W^{+}W^{-}$$ $${\rightarrow }$$ $${\ell }^{-}\bar{\nu }_{\ell }{\ell }^{{\prime }+}{\nu }_{{\ell }^{\prime }}$$ with $${\ell }$$ , $${\ell }^{\prime }$$ $$=$$ $\textit{e}$ and $${\mu }$$ , could be experimentally observed, when considering the realistic identification efficiency of the charged lepton and assuming more than $$3{\times }10^{7}$$ $${\eta }_{t}$$ events available at the future HL-LHC. We propose searching for $${\eta }_{t}$$ via the $${\eta }_{t}$$ $${\rightarrow }$$ $$W^{+}W^{-}$$ $${\rightarrow }$$ $${\ell }^{-}\bar{\nu }_{\ell }{\ell }^{{\prime }+}{\nu }_{{\ell }^{\prime }}$$ channel, which features no $\textit{b}$-jets and clean dilepton signatures, thus offering a complementary and potentially more sensitive probe.

Yueling Yang

Bingbing Yang

Junfeng Sun

Prospects for observing the $${\eta }_{t}$$ $${\rightarrow }$$ $$W^{+}W^{-}$$ decay at the HL-LHC

In this study, we investigate the influence of deconfined QCD matter on quarkonium spin alignment in ultra-relativistic heavy-ion collisions. We estimate the spin alignment of charmonium ( $$J/\psi $$ , and $$\psi $$ (2 S)) and bottomonium ( $$\Upsilon $$ (1 S), and $$\Upsilon $$ (2 S)) states for Pb+Pb collisions at $$\sqrt{s_\textrm{NN}} = 5.02$$ TeV as a function of transverse momentum by calculating the energy eigenvalues in a thermal rotating medium. We solve the Schrödinger equation with a medium-modified color-singlet potential, considering the coupling of spin with vorticity and magnetic field. Furthermore, we evaluate the effect of medium temperature, vorticity, magnetic field, and momentum-space anisotropy on the elements of the spin density matrix. Our findings reveal that vorticity increases the spin alignment, while the magnetic fields and anisotropy modify the observables in a state-dependent manner. These findings deepen our understanding of quarkonium spin alignment in an anisotropic magneto-vortical thermal medium, shedding light on spin transport phenomena in heavy-ion collisions.

Bhagyarathi Sahoo

Captain Singh

Raghunath Sahoo

Spin alignment of quarkonia: a possible probe of deconfined QCD matter in Pb+Pb collisions at $$\sqrt{s_\textrm{NN}} = 5.02$$ TeV