Kaniadakis holographic dark energy is a one-parameter extension of the standard HDE framework, in which the horizon entropy is reformulated using Kaniadakis entropy. At the cosmological level, it has been shown to give rise to modified Friedmann equations, leading to a richer phenomenology compared to $$\Lambda $$ CDM. In this work we test the Kanadiakis holography model against multiple late-time observational probes, including Type Ia supernovae from PantheonPlus and Union3, Cosmic Chronometer measurements of the Hubble parameter and Baryon Acoustic Oscillation from the Dark Energy Spectroscopic Instrument Data Release 2 (DESI DR2). Using a Bayesian inference approach with MCMC methods, we constrain the cosmological parameters of the model and evaluate its performance against $$\Lambda $$ CDM through the Akaike Information Criterion. We find that Kaniadakis holography can provide a better fit for some data combinations, although $$\Lambda $$ CDM remains slightly statistically favored overall. These results highlight Kaniadakis holography as a competitive alternative to the standard cosmological model, offering valuable insights into the role of generalized entropy in dark energy dynamics.

Spain

Giuseppe Luciano

South Africa

Chile

Andronikos Paliathanasis

Late-time cosmological constraints on Kaniadakis holographic dark energy

In this paper, we utilize the maximum entropy prescription to determine a quantum state of a small collision system at the kinetic freeze-out. We derive expressions for multiplicity-selected particle momentum spectra and correlation functions by applying a fixed particle number constraint to this state. The results of our analysis can be useful for interpreting the multiplicity dependence of the particle momentum spectra and correlations in high-multiplicity <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi></math> collision events at a fixed LHC energy.

Ukraine

S.V. Akkelin

Particle momentum spectra, correlations, and maximum entropy principle in high-multiplicity collision events

We investigate thermal properties of a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></math> lattice gauge theory in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mo>+</mo><mn>1</mn></math> dimensions through real-time simulations. We extract the spectral functions directly coupling to the pseudoscalar and scalar mesons, demonstrating the thermal modifications of these states with increasing temperatures. Introducing the notion of energy-flow operators, we quantify the temporal buildup of correlations in the energy flows across the lattice. We demonstrate that energy-energy correlators fail to factorize to products of energy flows, both in the vacuum and at nonzero temperature, indicating the presence of nontrivial correlations in the quantum states. Our results constitute a first real-time ab initio study of bound-state thermal broadening and finite temperature energy-flow correlations in a gauge theory, providing a benchmark for future studies of hadronic matter under extreme conditions.

CERN

João Barata

United States

David Frenklakh

Swagato Mukherjee

Thermal modifications of mesons and energy-energy correlators from real-time simulations of a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></mrow></math> lattice gauge theory

We analyze the vacuum fluctuations and the stress-energy tensor of a scalar field of mass <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>M</mi></math> in a conical spacetime, where the topological singularity at the apex requires boundary conditions for the field equation. The necessity of boundary conditions was established by Kay and Studer in the early 1990s, while for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>M</mi><mo>=</mo><mn>0</mn></math> stability is achieved only under Dirichlet boundary conditions, and for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>M</mi><mo>&gt;</mo><mi>q</mi></math> the field is stable and a localized mode emerges. This mode admits a natural interpretation as a covariant model of an extended particle detector, which allows us to investigate how such detectors modify the local vacuum structure. In this framework, the renormalized stress-energy tensor offers a natural way to quantify the influence of the detector on the surrounding spacetime.

Brazil

João Paulo M. Pitelli

Ricardo A. Mosna

Victor H.M. Ramos

João C.A. Barata

Vacuum fluctuations and the renormalized stress-energy tensor on a cone with arbitrary boundary conditions

We propose an explanation for the recently reported ultrahigh-energy neutrino signal at KM3NeT, which shows no clear association with known astrophysical sources. While decaying dark matter in the Galactic Center is a natural candidate, the observed arrival direction strongly suggests an extragalactic origin. We introduce a multicomponent dark matter scenario in which the components are part of a supermultiplet, with supersymmetry ensuring a nearly degenerate mass spectrum among the fields with different spins. In this setup, a cosmologically long-lived fermionic state decays into a slightly lighter bosonic dark matter state, producing a boosted neutrino spectrum with energy <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>E</mi><mi>ν</mi></msub><mo>∼</mo><mn>100</mn><mtext> </mtext><mtext> </mtext><mi>PeV</mi></math>, determined by the mass difference. The heavy-to-light decay occurs at a cosmological redshift of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>z</mi><mo>∼</mo><mrow><mi mathvariant="normal">a</mi><mtext> </mtext><mi>few</mi></mrow></math> or higher, leading to an isotropic directional distribution of the signal.

South Korea

Yongsoo Jho

Seong Chan Park

Chang Sub Shin

Superheavy supersymmetric dark matter as the origin of the KM3NeT ultrahigh energy signal

NuMI Off-axis <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>e</mi></msub></math> Appearance (NOvA) experiment is an ongoing long-baseline neutrino oscillation experiment. The primary channels of interest are the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>e</mi></msub></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>e</mi></msub></math> appearance, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>μ</mi></msub></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>μ</mi></msub></math> disappearance channels analyzed in the energy window <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mo>&lt;</mo><msub><mi>E</mi><mi>ν</mi></msub><mo>&lt;</mo><mn>4</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>. However, NOvA far detector sees nontrivial high-energy <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>e</mi></msub></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>e</mi></msub></math> events in the energy range <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>4</mn><mo>&lt;</mo><msub><mi>E</mi><mi>ν</mi></msub><mo>&lt;</mo><mn>20</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>. These high-energy events provide us with an opportunity to investigate the subleading new physics scenarios. In this context, we study the sensitivity of the NOvA experiment to constrain the nonstandard interaction (NSI) parameters and environmental decoherence parameters. We observe that by including high energy events (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>signal</mi><mo>+</mo><mtext>background</mtext></mrow></math>) the degeneracy around <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ε</mi><mrow><mi>e</mi><mi>τ</mi></mrow></msub><mo>∼</mo><mn>1.6</mn></math> can be removed throughout the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>δ</mi><mrow><mi>C</mi><mi>P</mi></mrow></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>δ</mi><mrow><mi>e</mi><mi>τ</mi></mrow></msub></math> range. Further, we examine the role of signal versus beam background events in removing this degeneracy. In addition, we constrain the decoherence parameter <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Γ</mi></math> considering events from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1</mn><mo>&lt;</mo><msub><mrow><mi>E</mi></mrow><mrow><mi>ν</mi></mrow></msub><mo>&lt;</mo><mn>20</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></mrow></math>. Later, assuming the presence of decoherence in nature we obtain the allowed regions in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>θ</mi><mn>23</mn></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>δ</mi><mrow><mi>C</mi><mi>P</mi></mrow></msub></math> plane.

India

Chinmay Bera

K.N. Deepthi

Probing new physics scenarios using high energy events at the NOvA far detector

The standard model of the universe, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>λ</mi><mi>CDM</mi></math>, is based on the Friedmann-Lemaître-Robertson-Walker metric with a flat three-dimensional coordinate space and the Friedmann equations Navas et al. [<a href="http://dx.doi.org/10.1103/PhysRevD.110.030001">Phys. Rev. D 110, 030001 (2024)</a>.]. The cosmological constant <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>λ</mi></math> provides the cancellation of the matter field contributions in the flat (Minkowski) space, as was proposed long ago in 1967 by Zeldovich for the first time to our knowledge Zeldovich [JETP Lett. 6, 316 (1967)]; see also Krasinski and Zeldovich [<a href="http://dx.doi.org/10.1070/PU1968v011n03ABEH003927">Sov. Phys. Usp. 11, 381 (1968)</a>]. The dynamical dark energy appears on the surface of the vacuum energy of matter fields at the flat (Minkowski) space. Within the Standard Model, the gluon Yang-Mills (YM) fields are playing a specific role since the properties of their vacuum, where there is the presence of the gluon condensate, provide the nonperturbative vacuum energy. It is natural to apply the successful instanton liquid model of the QCD vacuum and its lowest excitations. Our aim is to calculate the contribution of gluon YM fields to the dark energy density. We find that the universe metric is generating the QCD vacuum excitation, which gives the contribution to the dark energy density. But this one may hardly play a central role in the dynamics of the universe, since its timescale is too small. We also find the equation-of-state parameters <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>w</mi><mn>0</mn></msub><mo>=</mo><mo>−</mo><mn>1</mn><mo>,</mo><msub><mi>w</mi><mi>a</mi></msub><mo>=</mo><mn>0</mn></math> in accordance with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>λ</mi><mi>CDM</mi></math>, while the newest data, analyzed at Shajib and Frieman [<a href="http://dx.doi.org/10.1103/kjpb-r698">Phys. Rev. D 112, 063508 (2025)</a>.], give them at least in the range <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>−</mo><mn>0.91</mn><mo>&lt;</mo><msub><mi>w</mi><mn>0</mn></msub><mo>&lt;</mo><mo>−</mo><mn>0.73</mn><mo>,</mo><mspace linebreak="goodbreak"></mspace><mo>−</mo><mn>1.05</mn><mo>&lt;</mo><msub><mi>w</mi><mi>a</mi></msub><mo>&lt;</mo><mo>−</mo><mn>0.65</mn></math>. They are requesting a contribution from an ultralight scalar such as an axion, or from YM field topological configurations with the nontrivial holonomy due to the deviation from a pure de Sitter state Van Waerbeke and Zhitnitsky [DESI results and dark energy from QCD topological sectors, <a href="http://arXiv.org/abs/2506.14182">arXiv:2506.14182</a>.].

Uzbekistan

M.M. Musakhanov

Dark energy and QCD instanton vacuum in a Friedmann-Lemaître-Robertson-Walker universe

Based on a sample of $2.7\times10^{9}$ $\psi(3686)$ events collected by the BESIII detector operating at the BEPCII collider, the decay $\psi(3686)\to\gamma\chi_{cJ}, \chi_{cJ}\to\eta\eta\eta^{\prime}$ is analyzed. The decay modes $\chi_{c1}$ and $\chi_{c2}\to\eta\eta\eta^{\prime}$ are observed for the first time, and their corresponding branching fractions are determined to be ${\cal{B}}(\chi_{c1}\to\eta\eta\eta^{\prime}) = $ $ (1.40\, \pm 0.13\, (\text{stat.}) \pm 0.09\, (\text{sys.})) \times 10^{-4}$ and ${\cal{B}}(\chi_{c2}\to\eta\eta\eta^{\prime}) = (4.18\, \pm 0.84\, (\text{stat.}) \pm 0.48\, (\text{sys.})) \times 10^{-5}$ . An upper limit on the branching fraction of $\chi_{c0}\to\eta\eta\eta^{\prime}$ is set as $2.59 \times 10^{-5}$ at a 90% confidence level (CL). A partial wave analysis (PWA) of the decay $\chi_{c1}\to\eta\eta\eta^{\prime}$ is performed to search for the $1^{-+}$ exotic state $\eta_1(1855)$ . The PWA result indicates that the structure in the $\eta\eta^{\prime}$ mass spectrum is attributed to $f_0(1500)$ , while in the $\eta\eta$ mass spectrum, it is attributed to the $0^{++}$ phase space. The upper limit of ${\cal{B}}(\chi_{c1}\to\eta_{1}(1855)\eta) \cdot {\cal{B}}(\eta_{1}(1855)\to\eta\eta^{\prime}) \lt $ $ 9.79 \times 10^{-5}$ is set based on the PWA at 90% CL.

China

M. Ablikim

Russia

M.N. Achasov

Sweden

P. Adlarson

X.C. Ai

Germany

R. Aliberti

Italy

A. Amoroso

Q. An

Y. Bai

O. Bakina

Y. Ban

H.R. Bao

Poland

V. Batozskaya

Mongolia

K. Begzsuren

N. Berger

M. Berlowski

M. Bertani

D. Bettoni

F. Bianchi

E. Bianco

A. Bortone

I. Boyko

R.A. Briere

A. Brueggemann

H. Cai

M.H. Cai

X. Cai

A. Calcaterra

G.F. Cao

N. Cao

Türkiye

S.A. Cetin

X.Y. Chai

J.F. Chang

G.R. Che

Y.Z. Che

C.H. Chen

Chao Chen

G. Chen

H.S. Chen

H.Y. Chen

M.L. Chen

S.J. Chen

S.L. Chen

S.M. Chen

T. Chen

X.R. Chen

X.T. Chen

X.Y. Chen

Y.B. Chen

Y.Q. Chen

Z. Chen

Z.J. Chen

Z.K. Chen

S.K. Choi

X. Chu

G. Cibinetto

F. Cossio

United Kingdom

J. Cottee-Meldrum

J.J. Cui

H.L. Dai

J.P. Dai

A. Dbeyssi

R.E. de Boer

D. Dedovich

C.Q. Deng

Z.Y. Deng

A. Denig

I. Denysenko

M. Destefanis

F. De Mori

B. Ding

X.X. Ding

Y. Ding

Y.X. Ding

J. Dong

L.Y. Dong

M.Y. Dong

X. Dong

M.C. Du

S.X. Du

Y.Y. Duan

P. Egorov

G.F. Fan

J.J. Fan

Y.H. Fan

J. Fang

S.S. Fang

W.X. Fang

Y.Q. Fang

R. Farinelli

L. Fava

F. Feldbauer

G. Felici

C.Q. Feng

J.H. Feng

L. Feng

Q.X. Feng

Search for $\textit{η}$ $_{1}$(1855) in $\textit{χ}$ $\textit{cJ}$ → $\textit{ηηη}$′ decays * Supported in part by National Key R&D Program of China (2023YFA1606000, 2023YFA1606704); National Natural Science Foundation of China (NSFC) (11635010, 11935015, 11935016, 11935018, 12025502, 12035009, 12035013, 12061131003, 12192260, 12192261, 12192262, 12192263, 12192264, 12192265, 12221005, 12225509, 12235017, 12361141819); the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program; CAS (YSBR-101); 100 Talents Program of CAS; The Institute of Nuclear and Particle Physics (INPAC) and Shanghai Key Laboratory for Particle Physics and Cosmology; Agencia Nacional de Investigación y Desarrollo de Chile (ANID), Chile (ANID PIA/APOYO AFB230003); German Research Foundation DFG (FOR5327); Istituto Nazionale di Fisica Nucleare, Italy; Knut and Alice Wallenberg Foundation (2021.0174, 2021.0299); Ministry of Development of Turkey (DPT2006K-120470); National Research Foundation of Korea ( NRF-2022R1A2C1092335); National Science and Technology fund of Mongolia; National Science Research and Innovation Fund (NSRF) via the Program Management Unit for Human Resources Institutional Development, Research and Innovation of Thailand ( B50G670107); Polish National Science Centre (2024/53/B/ST2/00975); Swedish Research Council (2019.04595); U. S. Department of Energy (DE-FG02-05ER41374)

We study the pole trajectory of the recently established subthreshold negative-parity nucleon pole, namely the $N^*(920)$ , with varying pion masses in the scheme of linear $\textit{σ}$ model with nucleons, using the $N/D$ unitarization method. We find that, as the pion mass increases, the pole moves toward the real axis. For larger pion masses, at tree level, the pole falls to a specific point on $\textit{u}$-channel cut and crosses to the adjacent Riemann sheet defined by the logarithmic $\textit{u-}$channel cut. At the one-loop level, the pole does not meet the $\textit{u}$-cut up to $m_\pi=0.36$ GeV. We also re-examined the $\textit{σ}$ pole trajectory and found it to be in good agreement with the Roy equation analysis result.

Qu-Zhi Li

Zhiguang Xiao

Han-Qing Zheng

On the pole trajectory of the subthreshold negative parity nucleon with varying pion masses * Supported by China National Natural Science Foundation (12335002, 12375078). This work is also supported by “the Fundamental Research Funds for the Central Universities”

The energy-momentum tensor (EMT) of the proton encodes fundamental information about its mass, pressure, and shear distributions. Using recent lattice QCD data for the gravitational form factors, we show that the Breit-frame Wigner EMT may be of Hawking-Ellis type IV in the proton’s core. Such EMT violates all pointwise energy conditions and lacks a causal rest frame so that the usual mechanical picture fails at short distances. We define the gravitational radius—a new hadronic observable—marking the scale where the EMT becomes ordinary (type I) and the classical interpretation is restored. We also derive from the averaged null energy condition nonperturbative, model-independent quantum field theory constraints on gravitational form factors.

Adrian Dumitru

Jorge Noronha

Violation of energy conditions and the gravitational radius of the proton