Using accurate computational methods, we compute the quasinormal frequencies of a massive scalar field propagating near a black hole in the framework of non-minimal Einstein–Yang–Mills theory with a non-zero cosmological constant. We show that increasing the mass of the scalar field significantly decreases the damping rate of the quasinormal modes for both asymptotically flat and de Sitter black holes. However, in the de Sitter case, arbitrarily long-lived modes can exist, whereas in the asymptotically flat case, the damping rate never vanishes completely. In the limit of quasi-resonances, we observe a kind of universal behavior where the frequencies do not depend on the coupling constant. Applying the time-domain integration of perturbation equations we show that even when the effective potential has a negative gap, the scalar field is stable and the perturbations decay in time. In the regime of large mass of the field we obtain the analytic formula for quasinormal modes.

Spain

Alexey Dubinsky

Long-lived quasinormal modes and quasi-resonances around non-minimal Einstein–Yang–Mills black holes

We explored the effect of space-time geometry on the trajectory of light rays in the context of a charged, rotating black hole. We derived an analytical expression for the deflection of light rays in Kerr–Newman space-time geometry, using a material medium approach, on non-equatorial plane. From this deflection angle expression it is evident that the charge and rotation of the black hole can affect the light rays’ paths. For Kerr–Newman geometry, the deflection angle decreases with increasing charge when the rotation parameter is held constant. Conversely, for a constant charge, the deflection angle increases with the rotation parameter for prograde and decreases for retrograde trajectories. Applying both factors results in the deflection angle being lower than that of the Schwarzschild geometry. Non-equatorial study of the deflection angle reveals that it is maximum in the equatorial plane than in the pole. The frame-dragging effects in the Kerr–Newman field were taken into account to calculate the velocity of light rays, leading to the determination of the refractive index in this field geometry. This study concludes that, depending on the values of the rotation parameter and charge parameter, both prograde and retrograde trajectories coincide, result in that at some point the frame dragging effect is the same for prograde and retrograde motion. Also, the frame dragging effect increases towards poles than the equatorial plane, and this nontrivial nature results because of the interplay between charge, rotation parameter and rotation frequency of the black hole.

India

Saswati Roy

Shubham Kala

Prasanjit Ghosh

Hemwati Nandan

Asoke Sen

Non-equatorial deflection of light due to Kerr–Newman black hole: a material medium approach

We present an extensive phenomenological study of a scotogenic framework including a scalar singlet, a scalar doublet, a fermionic doublet, and two generations of a fermionic triplet, allowing to provide three non-zero neutrino masses and three viable dark matter candidates. Using a Markov Chain Monte Carlo numerical technique, we probe the parameter space of the model in view of numerous constraints stemming from dark matter, the neutrino sector, and lepton-flavour violating transitions. The dark matter mass distribution of phenomenologically viable scenarios exhibits three very predictive peaks at 550 GeV, 1080 GeV, and 2300 GeV. In all viable parameter regions, the observed relic density is achieved through dominant co-annihilations. Future experiments will be able to probe a large number of the currently viable parameter space, while certain parameter configurations promise interesting collider signatures. For related studies, five typical parameter configurations are given in SLHA format.

France

Ugo Noyers

Colombia

Maud Sarazin

Björn Herrmann

Phenomenology of a singlet–doublet–triplet scotogenic framework

Previous studies have identified potential instabilities in self-interacting vector theories associated with the breakdown of the well-posedness of the initial-value problem. However, these conclusions are restricted to Abelian vector fields, leaving room to explore alternative setups, such as non-Abelian vector fields with internal symmetries. Building on this idea, we study the well-posed 1 + 1 evolution of self-interacting SU(2) vector fields minimally coupled to gravity within the framework of the ’t Hooft–Polyakov magnetic monopole configuration. In this context, we present a counterexample in which self-interacting vector fields retain a well-posed initial value problem formulation. Remarkably, this system exhibits the same characteristic speeds as those found in general relativity (GR) in one spatial dimension. Unlike its Abelian counterpart, we achieve stable numerical evolutions across a wide range of initial conditions within a fully non-linear dynamical background, as evidenced in our time integration algorithm. Although our conclusions are strictly valid for the spherical symmetry case with only magnetic part for the vector field, this study serves as a valuable diagnostic tool for investigating more realistic astrophysical scenarios in three-dimensional settings and under more general background and vector field configurations.

Chile

Gabriel Gómez

Italy

José Rodríguez

Internal symmetry to the rescue: well-posed 1 + 1 evolution of self-interacting vector fields

In this paper, a systematic investigation is conducted to explore the potential molecular states formed by heavy meson pairs $$D^{(*)}D^{(*)}$$ and $$D^{(*)}{\bar{D}}^{(*)}$$ with the complex scaling method, in the framework of the one-boson-exchange (OBE) model. The exchange interactions are mediated by the pseudoscalar, scalar and vector mesons( $$\pi $$ , $$\sigma $$ , $$\rho $$ , $$\omega $$ ). The interaction potential within the OBE model is derived using the Bonn approximation, followed by the application of the complex scaling method to determine the bound and resonant states. The results demonstrate that the $$D^{(*)}D^{(*)}$$ and $$D^{(*)}{\bar{D}}^{(*)}$$ systems can form not only multiple bound states, but also several P-wave resonant states. In the hadronic molecular state framework, the $\textit{X}$(3872), $$T_{cc}^+$$ , and $$Z_c(3900)$$ states can be consistently explained as bound states, while the $\textit{G}$(3900) can be interpreted as a P-wave resonant state. Furthermore, we also predict other new bound and resonant states, which have the potential to be observed experimentally.

China

Jia-Liang Lu

Mao Song

Peng Wang

Jian-You Guo

Gang Li

Xuan Luo

The bound and resonant states of $$D^{(*)}D^{(*)}$$ and $$D^{(*)}{\bar{D}}^{(*)}$$ with the complex scaling method

This paper presents the primary charged-particle multiplicity distributions in proton–lead collisions at a centre-of-mass energy per nucleon–nucleon collision of $$\sqrt{s_{\textrm{NN}}}~=~5.02$$ TeV. The distributions are reported for non-single diffractive collisions in different pseudorapidity ranges. The measurements are performed using the combined information from the Silicon Pixel Detector and the Forward Multiplicity Detector of ALICE. The multiplicity distributions are parametrised with a double negative binomial distribution function which provides satisfactory descriptions of the distributions for all the studied pseudorapidity intervals. The data are compared to models and analysed quantitatively, evaluating the first four moments (mean, standard deviation, skewness, and kurtosis). The shape evolution of the measured multiplicity distributions is studied in terms of KNO variables and it is found that none of the considered models reproduces the measurements. This paper also reports on the average charged-particle multiplicity, normalised by the average number of participating nucleon pairs, as a function of the collision energy. The multiplicity results are then compared to measurements made in proton–proton and nucleus–nucleus collisions across a wide range of collision energies.

S. Acharya

A. Agarwal

Switzerland

G. Rinella

L. Aglietta

M. Agnello

N. Agrawal

Z. Ahammed

S. Ahmad

South Korea

S. Ahn

Slovakia

I. Ahuja

A. Akindinov

Germany

V. Akishina

M. Al-Turany

D. Aleksandrov

B. Alessandro

H. Alfanda

Mexico

R. Molina

B. Ali

A. Alici

United States

N. Alizadehvandchali

A. Alkin

Norway

J. Alme

G. Alocco

T. Alt

A. Altamura

I. Altsybeev

J. Alvarado

M. Anaam

Romania

C. Andrei

United Kingdom

N. Andreou

A. Andronic

E. Andronov

V. Anguelov

F. Antinori

P. Antonioli

N. Apadula

H. Appelshäuser

C. Arata

S. Arcelli

R. Arnaldi

Brazil

J. Arneiro

I. Arsene

M. Arslandok

A. Augustinus

R. Averbeck

D. Averyanov

M. Azmi

Japan

H. Baba

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

Sweden

S. Basu

G. Batigne

D. Battistini

B. Batyunya

D. Bauri

Peru

J. Bazo Alba

Denmark

I. Bearden

P. Becht

D. Behera

I. Belikov

A. Bell Hechavarria

F. Bellini

R. Bellwied

S. Belokurova

L. Beltran

Y. Beltran

G. Bencedi

A. Bensaoula

S. Beole

Y. Berdnikov

A. Berdnikova

L. Bergmann

L. Bernardinis

L. Betev

P. Bhaduri

A. Bhasin

B. Bhattacharjee

Charged-particle multiplicity distributions over a wide pseudorapidity range in p–Pb collisions at $$\sqrt{{{\varvec{s}}}_{{\textbf {NN}}}}={\textbf {5.02}}$$ TeV

This paper presents results on multiplicity fluctuations of positively and negatively charged hadrons as well as net-electric charge fluctuations measured in central Ar+Sc interactions at beam momenta 13$\textit{A}$, 19$\textit{A}$, 30$\textit{A}$, 40$\textit{A}$, 75$\textit{A}$, and 150 $$A\,\hbox {GeV}\!/\!c$$ . The fluctuation analysis is one of the tools to search for the predicted critical point of strongly interacting matter. Results are corrected for the experimental biases and quantified using cumulant ratios. In most instances, multiplicity and net-charge distributions appear narrower than the corresponding Poisson or Skellam distributions. Cumulant ratios are compared with the model predictions, which provide a qualitative description that aligns with observations for positively and negatively charged particles. The obtained results are also compared to earlier NA61/SHINE results from inelastic $\textit{p+p}$ interactions in the same analysis acceptance.

H. Adhikary

P. Adrich

K. Allison

N. Amin

I.C. Arsene

M. Bajda

Y. Balkova

D. Battaglia

A. Bazgir

S. Bhosale

M. Bielewicz

A. Blondel

Bulgaria

M. Bogomilov

Y. Bondar

W. Bryliński

J. Brzychczyk

Russia

M. Buryakov

A. Camino

Y. Chandak

Serbia

M. Ćirković

M. Csanád

J. Cybowska

T. Czopowicz

C. Dalmazzone

N. Davis

A. Dmitriev

P. Doetinchem

W. Dominik

J. Dumarchez

R. Engel

G. Feofilov

L. Fields

Z. Fodor

M. Friend

M. Gaździcki

K. Gollwitzer

O. Golosov

V. Golovatyuk

M. Golubeva

K. Grebieszkow

F. Guber

P. Hurh

S. Ilieva

A. Ivashkin

Multiplicity and net-electric charge fluctuations in central Ar+Sc interactions at 13$\textit{A}$, 19$\textit{A}$, 30$\textit{A}$, 40$\textit{A}$, 75$\textit{A}$, and 150 $$A\,\hbox {GeV}\!/\!c$$ beam momenta measured by NA61/SHINE at the CERN SPS