The transverse momentum spectra and integrated yields of anti- $$\Sigma $$ hyperons ( $$\overline{\Sigma }^{\pm } $$ ) have been measured in $$\text {pp}$$ and $$\text {p}{-}\text {Pb}$$ collisions at $$\sqrt{s_{\textrm{NN}}}=5.02$$ TeV with the ALICE experiment. Measurements are performed via the newly accessed decay channel $$\overline{\Sigma }^{\pm } \!\!\rightarrow \mathrm{\overline{n}} \pi ^{\pm }$$ . A new method of antineutron reconstruction with the PHOS electromagnetic spectrometer is developed and applied to this analysis. The $$p_{\textrm{T}}$$ spectra of $$\overline{\Sigma }^{\pm } $$ are measured in the range $$0.5<p_{\textrm{T}} <3$$ GeV/ $$c$$ and compared to predictions of the PYTHIA 8, DPMJET, PHOJET, EPOS LHC and EPOS4 models. The EPOS LHC and EPOS4 models provide the best descriptions of the measured spectra both in $$\text {pp}$$ and $$\text {p}{-}\text {Pb}$$ collisions, while models which do not account for multiparton interactions provide a considerably worse description at high $$p_{\textrm{T}}$$ . The total yields of $$\overline{\Sigma }^{\pm } $$ in both $$\text {pp}$$ and $$\text {p}{-}\text {Pb}$$ collisions are compared to predictions of the Thermal-FIST model and dynamical models PYTHIA 8, DPMJET, PHOJET, EPOS LHC and EPOS4. All models reproduce the total yields in both colliding systems within uncertainties. The nuclear modification factors $$R_\textrm{pPb}$$ for both $$\overline{\Sigma }^{+} $$ and $$\overline{\Sigma }^{-} $$ are evaluated and compared to those of protons, $$\Lambda $$ and $$\Xi $$ hyperons, and predictions of EPOS LHC and EPOS4 models. No deviations of $$R_\textrm{pPb}$$ for $$\overline{\Sigma }^{\pm } $$ from the model predictions or measurements for other hadrons are found within uncertainties.

United States

I. Abualrob

Italy

S. Acharya

Switzerland

G. Aglieri Rinella

L. Aglietta

M. Agnello

N. Agrawal

India

Z. Ahammed

S. Ahmad

Slovakia

I. Ahuja

Indonesia

ZUL. Akbar

A. Akindinov

Germany

V. Akishina

M. Al-Turany

D. Aleksandrov

B. Alessandro

China

H. Alfanda

Mexico

R. Alfaro Molina

B. Ali

A. Alici

South Korea

A. Alkin

Norway

J. Alme

G. Alocco

T. Alt

A. Altamura

I. Altsybeev

Romania

C. Andrei

United Kingdom

N. Andreou

A. Andronic

E. Andronov

V. Anguelov

F. Antinori

P. Antonioli

N. Apadula

H. Appelshäuser

France

C. Arata

S. Arcelli

R. Arnaldi

Brazil

J. Arneiro

I. Arsene

M. Arslandok

A. Augustinus

R. Averbeck

M. Azmi

Japan

H. Baba

A. Babu

A. Badalà

J. Bae

Y. Bae

Y. Baek

X. Bai

R. Bailhache

Y. Bailung

R. Bala

A. Baldisseri

Poland

B. Balis

S. Bangalia

Z. Banoo

V. Barbasova

F. Barile

L. Barioglio

Greece

M. Barlou

B. Barman

Hungary

G. Barnaföldi

L. Barnby

E. Barreau

V. Barret

L. Barreto

K. Barth

E. Bartsch

N. Bastid

G. Batigne

D. Battistini

B. Batyunya

D. Bauri

Peru

J. Bazo Alba

Denmark

I. Bearden

P. Becht

D. Behera

S. Behera

I. Belikov

V. Bella

F. Bellini

R. Bellwied

L. Beltran

Y. Beltran

G. Bencedi

A. Bensaoula

S. Beole

Y. Berdnikov

A. Berdnikova

L. Bergmann

L. Bernardinis

L. Betev

P. Bhaduri

T. Bhalla

A. Bhasin

B. Bhattacharjee

S. Bhattarai

L. Bianchi

Czechia

J. Bielčík

$$\overline{\Sigma }^{\pm }$$ production in $$\text {pp}$$ and $$\text {p}{-}\text {Pb}$$ collisions at $$\sqrt{s_{\textrm{NN}}} = 5.02$$ TeV with ALICE

We investigate scalar-induced gravitational waves (SIGWs) in the framework of spatially covariant gravity (SCG), a broad class of Lorentz-violating modified gravity theories respecting only spatial diffeomorphism invariance. Extending earlier SCG formulations, we compute the general kernel function for SIGWs on a flat Friedmann–Lemaître–Robertson–Walker background, focusing on polynomial-type SCG Lagrangians up to $$d=3$$ , where $\textit{d}$ denotes the total number of derivatives in each monomial. We derive explicit expressions for the kernel in the case of power-law time evolution of the coefficients, and restrict attention to the subset of SCG operators whose tensor modes propagate at the speed of light, thereby avoiding late-time divergences in the fractional energy density of SIGWs. Instead of the usual Newtonian gauge, the breaking of time reparametrization symmetry in SCG necessitates a unitary gauge analysis. We compute the energy density of SIGWs for representative parameter combinations, finding distinctive deviations from general relativity (GR), including scale-dependent modifications to both the amplitude and the spectral shape. Our results highlight the potential of stochastic GW background measurements to probe spatially covariant gravity and other Lorentz-violating extensions of GR.

Jiehao Jiang

Jieming Lin

Xian Gao

Scalar-induced gravitational waves in spatially covariant gravity

The simplest approach to include a mass into the electromagnetic vector potential is to modify the Einstein–Maxwell action to the Einstein–Proca form. There are currently no exact analytical solutions for this scenario. However, by using perturbation theory, where both the Proca mass and the black hole charge are small parameters, it is possible to find an exact analytical solution. In this solution, the metric tensor remains unchanged, but the vector potential deviates from the Coulomb potential. In particular, even if the Proca mass is limited by the value $$m_{\gamma }<10^{-48}\text {g}$$ , which is the current experimental upper limit for photon mass, it makes a significant contribution to the dynamical equations. In this paper, we study the motion of neutral and charged particles in the vicinity of a weakly Proca-charged black hole, and test the observational implications of the solution of the Einstein–Proca equations for gravitational bending, the black hole shadow, and the fit to the orbits of the Galactic center flares observed by the near-infrared GRAVITY instrument. We find that only extremely cold photons, which are likely scattered before reaching a distant observer, could reveal the non-zero photon mass effect through the black hole shadow. For the Galactic center flare analysis we obtained constraints on the dimensionless Proca parameter to $$\mu \le 0.125$$ for the electric interaction parameter in the range $$-1.1< \mathcal{Q} < 0.5$$ , which can be potentially tested by future GRAVITY flare astrometry. Since the Proca parameter is coupled to the black hole mass, the effect of the Proca charge becomes more pronounced for supermassive black holes compared to stellar-mass objects. Our perturbative treatment remains valid essentially up to the horizon, with divergences appearing only in the immediate near-horizon region, where a fully non-perturbative analysis would be required.

Abylaikhan Tlemissov

Arman Tursunov

Jiří Kovář

Zdeněk Stuchlík

Dynamical and observational properties of weakly Proca-charged black holes

In this work, we present an exact solution describing a static, spherically symmetric black hole immersed in a cored Navarro–Frenk–White (NFW) dark matter halo. We examine the energy conditions and find that the null, weak, strong and dominant energy conditions are all satisfied, confirming the physical plausibility of our solution. Furthermore, we examine its optical and scalar perturbation properties, highlighting their connections to the Lyapunov exponent and black hole thermodynamics. By applying the principle of least action, we derive the null geodesics to study gravitational lensing and light ring phenomena in the presence of the dark matter halo. The stability of photon orbits is analyzed using the Lyapunov exponent, which we relate to the imaginary part of the massless quasinormal modes in the eikonal limit. We also investigate the thermodynamic behavior of the black hole–dark matter system by evaluating the mass function, entropy, temperature, heat capacity, Gibbs free energy and the entropy to assess both local and global stability. Overall, our results demonstrate that the surrounding dark matter halo significantly influences the black hole’s properties, enhancing its thermodynamic stability and allowing the possibility of phase transitions.

Thailand

David Senjaya

Cored Navarro-Frenk-White dark matter halo: novel black hole solution, energy condition, optical properties, quasinormal modes and thermodynamics

Double Higgs production is challenging even at the High Luminosity LHC. The Standard Model (SM) $$hh\rightarrow b{\bar{b}}WW(ZZ)\rightarrow b{\bar{b}}\ell \ell \nu \nu $$ has a moderate cross section compared to other decay modes, but its backgrounds, mainly top quark pairs, are overwhelming. In this work, we propose new kinematic features designed to improve the discrimination of double Higgs pairs, in the $$b{\bar{b}}\ell \ell \nu \nu $$ channel, with cut-based and multivariate analyses. The new features are built with the neutrinos’ momenta solutions obtained from imposing mass constraints when calculating $\textit{Higgsness}$ and $\textit{Topness}$ variables. For the SM $\textit{hh}$ production, we estimate a $$3.7\sigma $$ statistical significance from an optimized cut-based strategy, improving about 20% over the best estimates of the literature, and $$5\sigma $$ from a multivariate analysis if systematic uncertainties on the backgrounds are small at the 14 TeV HL-LHC after 3000 $$\hbox {fb}^{-1}$$ . The new variables are constructed as ratios of kinematic functions of the particles’ momenta, being less prone to systematic errors. We also demonstrate the usefulness of the solutions in reconstructing heavy scalar resonances and other variables of phenomenological importance.

Alexandre Alves

Eduardo Silva Almeida

Diego Gonçalves

Observing double Higgs production at the LHC via neutrino feature engineering in $$hh\rightarrow b{\bar{b}}\ell \ell \nu \nu $$

For axially symmetric accretion maintained in hydrostatic equilibrium along the vertical direction, we investigate how the characteristic features of the embedded acoustic geometry depend on the background Kerr metric, and how such dependence is governed by two different expressions for the geometrical configurations of the matter flow. We first obtain the location of the sonic points and stationary shock between the sonic points. We then perturb the flow to obtain the corresponding metric elements of the acoustic space-time. We compute the value of the acoustic surface gravity as a function of the spin angular momentum of the rotating black hole for the different flow thicknesses considered in the present work.

Susovan Maity

Pratik Tarafdar

Md Shaikh

Souvik Ghose

Tapas Das

Effect of disc heights on acoustic surface gravity for accreting Kerr black holes

We investigate how deviations from the Bekenstein–Hawking entropy modify black-hole spacetimes through the recently proposed entropy-geometry correspondence. For four representative modified entropies, namely Barrow, Rényi, Kaniadakis, and logarithmic, we derive the corresponding effective metrics and analyze their thermodynamic and topological classification using the off-shell free energy and winding numbers. We show that Barrow and Rényi entropies yield a single unstable sector with global charge $$W=-1$$ , while logarithmic and Kaniadakis corrections produce canceling defects with $$W=0$$ , revealing topological structures absent in the Schwarzschild case. Using the modified metrics, we further calculate the photon-sphere radius and shadow size, showing that each modified entropy relation induces characteristic optical shifts. Thus, by comparing with Event Horizon Telescope observations of Sgr A $$^*$$ , we extract new bounds on all entropy-deformation parameters. Our results demonstrate that thermodynamic topology, together with photon-sphere phenomenology, offers a viable way to test generalized entropy frameworks and probe departures from the Bekenstein-Hawking area law.

Ankit Anand

North Macedonia

Kimet Jusufi

Cyprus

Spyros Basilakos

Chile

Emmanuel Saridakis

Topological and optical signatures of modified black-hole entropies

We study slowly rotating traversable wormholes embedded in realistic galactic dark matter halos, including Navarro–Frenk–White (NFW), Bose–Einstein Condensate (Thomas-Fermi, TF), and pseudo-isothermal (PI) profiles. Using the Teo-type rotating wormhole metric, we construct shape functions from halo density distributions and analyze the resulting geometrical properties, such as throat structure, flaring-out conditions, and violations of the null energy condition. We examine null geodesics, effective potentials, photon spheres, and Lense-Thirring (LT) precession, highlighting differences between cuspy and cored halo models. Finally, we calculate wormhole shadows, observing that cuspy NFW halos tend to produce smaller, asymmetric shadows, while cored TF and PI halos yield smoother, nearly circular silhouettes. The findings provide a theoretical characterization of photon dynamics and shadow morphology in wormholes embedded within different dark matter environments.

South Africa

Azerbaijan

Abdelghani Errehymy

Türkiye

Abdullah Guvendi

Semra Dogan

Omar Mustafa

Null geodesics and shadows of slowly rotating wormholes immersed in dark matter halos

We consider a $$(1+1)$$ -dimensional theory with a single real scalar field $$\phi $$ whose kinematics is modified by a generalizing function $$f(\phi )$$ . After briefly reviewing its Bogomol’nyi–Prasad–Sommerfield (BPS) structure, we focus on a particular $$f(\phi )$$ to obtain analytic BPS double-kink solutions in three different models governed by the $$\phi ^4$$ , $$\phi ^6$$ , and sine-Gordon superpotentials. In all cases, the resulting double-kinks approach the vacuum values by following an exponential decay, with the generalizing function controlling its dependence on $\textit{x}$ and mass. We also calculate the BPS bound explicitly and study how the double kinks behave near the origin. The energy distribution of the novel BPS states engenders symmetric two-lump profiles for the $$\phi ^4$$ and sine-Gordon superpotentials. Whereas, for the $$\phi ^6$$ superpotential, the BPS energy profiles form asymmetric two-lumps.

R. Casana

E. Hora

Fabiano Simas

Exact BPS double-kinks in generalized $$\phi ^4$$ , $$\phi ^6$$ and sine-Gordon models

The use of gaseous Time Projection Chambers enables the detection and the detailed study of rare events due to particles interactions with the atoms of the gas with energy releases as low as a few keV. Due to this capability, these instruments are being developed for applications in the field of astroparticle physics, such as the study of dark matter and neutrinos. To acquire events occurring in the sensitive volume with a high granularity, the collaboration is developing a solution where the light generated during the avalanche processes occurring in a multiplication stage based on Gas Electron Multiplier (GEM) is read out by optical sensors with very high sensitivity and spatial resolution. To achieve a high light output, gas gain values of the order of $$10^5\text {-}10^6$$ are needed. In this working condition, a dependence of the detector response on the spatial density of the charge collected in the GEM holes has been observed, indicating a gain-reduction effect likely caused by space-charge buildup within the multiplication channels. This paper presents data collected with a prototype featuring a sensitive volume of about two liters, together with a model developed by the collaboration to describe and predict the gain dependence on charge density. A comparison with experimental data shows that the model reproduces, with a percent-level precision, the gain behaviour over nearly one order of magnitude.

Portugal

Fernando Amaro

Rita Antonietti

Elisabetta Baracchini

Luigi Benussi

Stefano Bianco

Roberto Campagnola

Cesidio Capoccia

Michele Caponero

Gianluca Cavoto

Igor Costa

Antonio Croce

Emiliano Dané

Melba D’Astolfo

Giorgio Dho

Flaminia Di Giambattista

Emanuele Di Marco

Giulia D’Imperio

Joaquim Marques Ferreira dos Santos

Davide Fiorina

Francesco Iacoangeli

Zahoor Islam

Herman Lima

Ernesto Kemp

Francesca Lewis

Giovanni Maccarrone

Modeling the light response of an optically readout GEM based TPC for the CYGNO experiment