We study the classification problem for anomaly-free 6D 𝒩 = (1$\textit{,}$ 0) supergravities with a gauged abelian R-symmetry and one tensor multiplet. We present eleven new models with gauge group $\textit{G}$ × $\textit{U}$(1) that satisfy the local Green-Schwarz factorization condition, together with several recently proposed global consistency conditions. In particular, the low-rank models we found are precisely where some of the recent enumeration literature is least directly applicable. These examples suggest that the landscape of anomaly-free gauged $\textit{U}$(1) supergravities may be richer than previously recognized while still remaining highly constrained. We analyze the arithmetic structure of the anomaly coefficients, including their integral pairings, embeddability into rank-two unimodular charge lattices, the characteristic-vector condition and ghost-free gauge-field conditions. We show that $\textit{n}$ ≡ 8 (mod 12) is necessary and sufficient for the unimodular embeddability in the rank-two case, when the gauge group does not contain $\textit{SU}$(2), $\textit{SU}$(3) and $\textit{G}$ . For the characteristic-vector condition we verify sufficiency for the branches realized by our examples and identify a remaining branch requiring additional exclusion. We also present a detailed discussion of the contribution to the anomaly polynomial when the $\textit{D}$ Lie algebra is present. These results sharpen the boundary between anomaly-free 6D spectra, global-consistency constraints, and possible UV realization in string theory or F-theory.

United States

Katrin Becker

Qi You

Anomaly-free spectra, unimodular lattices and 6D R-symmetry gauged supergravity

Compact star cores reach extreme densities and may contain exotic dense-matter phases. Information about the exotic interiors of rapidly rotating pulsars can be inferred from r-mode oscillations, whose stability is governed by viscous dissipation. In this work, we model a compact star containing a possible mixed phase of hadronic and quark matter and employ a hybrid statistical framework based on Bayesian inference to infer the dissipation time scales associated with the hybrid phase. Using low-mass X-ray binaries (LMXB) timing observations together with mass–radius constraints from the Neutron Star Interior Composition Explorer (NICER) mission, we estimate the shear and bulk viscosity contributions to r-mode damping for a hybrid star of two layers. Our inference yields shear and bulk viscous dissipation time scales of $$\tau _s=(4.99^{+0.49}_{-0.52}) \times 10^8 T^{\frac{5}{3}}$$ s and $$\tau _B= (2.150^{+1.23}_{-0.60}) \times 10^{19} (T^4 10^{-12}+T^2 10^{-6})^{-1}\Omega ^{-2}$$ s respectively. The timescales thus obtained can be implemented to obtain the minima of the star’s rotation frequency at $$\Omega =451.87$$ Hz at temperature $$T=0.259$$ MeV for a hybrid star of mass 1.5 $$M_{\odot }$$ and $$\Omega =517.47$$ Hz at $$T=0.234$$ MeV for $$M=1.75 M_{\odot }$$ . We find that the instability window obtained through the inference framework effectively explains the observed stability of millisecond pulsars in both the radio and LMXB populations, particularly for XTE J0929-314 and XTE J1807-294, J0437-4715, J2124-3358, respectively. These results demonstrate that Bayesian inference combined with r-mode phenomenology provides a powerful and observationally consistent framework for constraining the transport properties of dense hybrid matter.

India

Khushbu Zala

Sreemoyee Sarkar

Modelling dissipative dynamics of r-mode instability in hybrid stars

<p>A search is performed for the electroweak pair production of charginos and associated production of a chargino and neutralino, each of which decays through an <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>R</mi></math>-parity-violating coupling into a lepton and a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Z</mi></math>, or Higgs boson. This search targets the Higgs boson decay channel of the charginos and neutralinos, using events with three or more <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi></math>-tagged jets and one or two electrons or muons. The analyzed data corresponds to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>140</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>fb</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>56</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> of proton-proton collision data produced by the Large Hadron Collider at center-of-mass energies of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13.6</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>, respectively, collected by the ATLAS experiment between 2015 and 2023. The data are found to be consistent with predictions from the Standard Model. The results are interpreted as limits at 95% confidence level on model-independent cross sections for processes beyond the Standard Model. Limits are also set on the production of charginos and neutralinos for a minimal supersymmetric Standard Model with an additional <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo>−</mo><mi>L</mi></math> gauge symmetry that is spontaneously broken. Charginos and neutralinos with masses between 150 GeV and 1100 GeV are excluded at 95% confidence level for a scenario in which they decay via Higgs bosons, assuming equal decay branching fractions to each lepton flavor. Additional limits on chargino and neutralino production are derived for flavor-specific decay scenarios where the charginos decay into a single lepton flavor.</p>

France

G. Aad

Norway

E. Aakvaag

B. Abbott

United Arab Emirates

S. Abdelhameed

Germany

K. Abeling

N.J. Abicht

S.H. Abidi

M. Aboelela

Morocco

A. Aboulhorma

Israel

H. Abramowicz

Italy

B.S. Acharya

A. Ackermann

Switzerland

J. Ackerschott

C. Adam Bourdarios

Poland

L. Adamczyk

S.V. Addepalli

United Kingdom

M.J. Addison

J. Adelman

Türkiye

A. Adiguzel

T. Adye

A.A. Affolder

Y. Afik

Spain

M.N. Agaras

A. Aggarwal

Romania

C. Agheorghiesei

A. Ahmad

F. Ahmadov

S. Ahuja

China

X. Ai

G. Aielli

A. Aikot

M. Ait Tamlihat

Sweden

T.P.A. Åkesson

Japan

D. Akiyama

N.N. Akolkar

S. Aktas

G.L. Alberghi

Canada

J. Albert

U. Alberti

P. Albicocco

S. Alderweireldt

Z.L. Alegria

CERN

M. Aleksa

I.N. Aleksandrov

C. Alexa

Greece

T. Alexopoulos

F. Alfonsi

M. Algren

M. Alhroob

Czechia

B. Ali

H.M.J. Ali

S. Ali

S.W. Alibocus

South Africa

M. Aliev

G. Alimonti

C. Allaire

B.M.M. Allbrooke

D.R. Allen

J.S. Allen

J.F. Allen

Australia

C.S. Alley

E.R. Almazan

A. Aloisio

Argentina

F. Alonso

C. Alpigiani

A. Alvarez Fernandez

M. Alves Cardoso

M.G. Alviggi

M. Aly

Brazil

Y. Amaral Coutinho

C. Amelung

M. Amerl

T. Amezza

B. Amini

K. Amirie

A. Amirkhanov

D. Amperiadou

S. An

C. Anastopoulos

T. Andeen

J.K. Anders

A.C. Anderson

A. Andreazza

S. Angelidakis

A. Angerami

A.V. Anisenkov

A. Annovi

C. Antel

E. Antipov

M. Antonelli

F. Anulli

M. Aoki

T. Aoki

M.A. Aparo

L. Aperio Bella

M. Apicella

C. Appelt

A. Apyan

M. Arampatzi

Search for charginos and neutralinos with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo>−</mo><mi>L</mi></math> <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>R</mi></math>-parity violating decays in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math> and 13.6 TeV <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi></math> collisions with the ATLAS detector

Hyperon-antihyperon pairs produced in high-energy electron-positron annihilation constitute a naturally spin-entangled system in the high-energy regime. Recently, a probabilistic amplification of entanglement, termed autodistillation, has been found in the daughter baryon-antibaryon pairs from hyperon decay and is constrained by an upper boundary. This work demonstrates that the quantum entanglement in this process may be accompanied by a decrease, constrained by a lower boundary, but it will not be completely lost. Thus, the entanglement of these systems undergoes redistribution within the phase space during the sequential decays of hyperons, highlighting the important role of hyperon polarization. By using the explicit spin density matrix of baryon pairs, it is also found that the quantumness of the system, characterized by quantum discord, always has the possibility to increase during decay processes, even when entanglement evaluated by concurrence and negativity does not increase.

Cong Li

Xu Cao

Ai-Qiang Guo

Chun-Xu Yu

Hong-Wei Zhang

Zhe Zhang

Entanglement redistribution of hyperon-antihyperon pair via sequential decay * Supported by the National Natural Science Foundation of China (12547111, 12447132, 12575089) and the National Key R&D Program of China (2023YFA1606703)

A search for the decay $ B^+\to D_s^+ K^+K^- $ has been reported by the LHCb Collaboration using $ pp $ collision data corresponding to an integrated luminosity of $4.8\;{\rm{fb}}^{-1}$ , collected at center-of-mass energies of 7, 8, and 13 TeV, in which no amplitude analysis of the $ K^+K^- $ subsystem was performed. In this work, we study the resonant contributions to the decay $ B^+\to D_s^+ K^+K^- $ within the perturbative QCD (PQCD) factorization framework. Contributions from the $\textit{S}$-wave resonances $ f_0(980) $ , $ f_0(1370) $ , and $ f_0(1500) $ , the $\textit{P}$-wave resonance $ \phi(1020) $ , and the $\textit{D}$-wave resonances $ f_2(1270) $ and $ f_2(1525) $ are taken into account. By introducing the corresponding two-meson distribution amplitudes for the $ K^+K^- $ system, we perform a complete perturbative analysis of the quasi-two-body decays $ B^+\to D_s^+(R\to)K^+K^- $ , where $\textit{R}$ denotes an intermediate resonance, and present the first PQCD predictions for the associated branching fractions. Using the narrow-width approximation, we further extract the branching fractions of the corresponding two-body decays $ B^+\to D_s^+R $ . Our results are consistent with the available experimental measurements and previous theoretical studies. Finally, we find that direct CP asymmetries vanish for these quasi-two-body decays within the Standard Model, so that any experimentally observed nonzero CP asymmetry would constitute a clear signal of physics beyond the Standard Model.

Zhi-Tian Zou

Jun-Peng Wang

Rui Zhou

Ying Li

Quasi-two-body decays $ {B^+\to D_s^+ (R\to) K^+K^-} $ in the perturbative QCD approach * Supported in part by the National Science Foundation of China (12375089, 12435004, 12075086), and the Natural Science Foundation of Shandong province (ZR2022ZD26, ZR2022MA035)

In this paper we analyze the optical appearance of black holes embedded in a cosmological background in some popular <italic>f</italic>( <italic>R</italic>) models which are often considered as viable alternatives to the &#923;CDM model in General Relativity. After obtaining analytical approximations for the Hubble rate <italic>H</italic>( <italic>z</italic>) and angular diameter distance <italic>d<inf>A</inf></italic>( <italic>z</italic>), we compute the approximate shadow size for a spherically symmetric black hole embedded in these <italic>f</italic>( <italic>R</italic>) models as viewed by a comoving observer located very far from the black hole. This is then compared with the shadow size of a black hole embedded in the &#923;CDM model as obtained recently in Bisnovatyi-Kogan &amp; Tsupko (PRD <bold>98</bold>, 084,020 (2018)). Differences in the shadow size for cosmological black holes between <italic>f</italic>( <italic>R</italic>) gravity and General Relativity are discussed in light of the recent observations by the EHT collaboration.

Malta

Joseph Sultana

Optical appearance of cosmological black holes in <italic>f</italic>( <italic>R</italic>) gravity

We numerically investigate the time evolution of several physical observables for the so-called 2 R-Charge Black Hole (2RCBH) model undergoing Bjorken flow. The 2RCBH model corresponds to a top-down holographic construction describing a strongly interacting conformal fluid defined at finite temperature and R-charge density. Taken together with previous findings for the purely thermal $$\mathcal {N}=4$$ Supersymmetric Yang–Mills (SYM) plasma, and the 1 R-Charge Black Hole (1RCBH) model, our results for the 2RCBH model provide strong numerical evidence for the existence of far-from-equilibrium correlations between the non-equilibrium holographic entropy defined through the area of the apparent horizon of dynamical bulk black holes, and the expectation value of the energy–momentum tensor of the dual boundary quantum field theory. Such correlations are relevant in the pre-hydrodynamic stages of some initial data evolved in time, and seem to hold at least for strongly interacting conformal fluids, be they charged or neutral.

Gustavo Oliveira

Venezuela

Willians Barreto

Romulo Rougemont

Bjorken flow of holographic R-charged plasmas

An intermediate scale R-axion faces an immediate obstruction from the Dine-Festuccia-Komargodski (DFK) bound on the superpotential, 2|⟨$\textit{W}$⟩| ≤ $\textit{f}$ $\textit{F}$, since for a nearly Minkowski vacuum it typically follows that $\textit{f}$ ≳ $\textit{M}$ . We show that this lower bound on $\textit{f}$ can be relaxed in an effective construction with the scalar potential tuned near zero via a mixed $\textit{F}$- and $\textit{D}$-term uplift, leading to a metastable vacuum in which the usual Planckian-$\textit{f}$ inference from the DFK argument is avoided locally. Validity of the effective field theory and metastability of the small $\textit{f}$ vacuum generically both imply a relaxed bound: $$ {f}_R\gtrsim \sqrt{m_{3/2}{M}_{\mathrm{Pl}}} $$ . We also highlight that if the R-symmetry has a QCD anomaly, this potentially permits the R-axion to play the role of the QCD axion. TeV-scale supersymmetry permits $\textit{f}$ ~ 10 GeV, this not only evades certain astrophysical and cosmological axion constraints, but notably lies in the window for which the observed dark matter abundance can be reproduced by the R-axion via the misalignment mechanism.

James Unwin

An intermediate scale R-axion & the QCD axion

The persistent 4–6 <italic>&#963;</italic> Hubble tension between Planck and SH0ES measurements challenges the standard &#923;CDM framework. We propose a solution combining generalized inhomogeneous spacetime geometry with Hu-Sawicki <italic>F</italic>( <italic>R</italic>) gravity. Using a spherically symmetric metric with independent functions <italic>A</italic>( <italic>t, r</italic>) and <italic>B</italic>( <italic>t, r</italic>), we show that local underdensities with modified gravity produce a &#8220;Hubble bubble&#8221; effect while maintaining global CMB consistency. Bayesian analysis incorporating SH0ES, Pantheon+, BAO, and cosmic chronometers yields <math altimg='si1.svg'><mrow><msubsup><mi>H</mi><mn>0</mn><mtext>local</mtext></msubsup><mo linebreak='goodbreak'>=</mo><mn>72.76</mn><mo>&#177;</mo><mn>1.18</mn></mrow></math> km/s/Mpc and <math altimg='si2.svg'><mrow><msubsup><mi>H</mi><mn>0</mn><mtext>global</mtext></msubsup><mo linebreak='goodbreak'>=</mo><mn>68.18</mn><mo>&#177;</mo><mn>0.76</mn></mrow></math> km/s/Mpc, reconciling the tension. The model achieves this through enhanced gravitational forces in underdense regions, chameleon screening preserving Solar System tests, and consistent structure formation. With <math altimg='si25.svg'><mrow><mi>ln</mi><mi>B</mi><mo linebreak='goodbreak'>=</mo><mn>2.28</mn><mo>&#177;</mo><mn>0.39</mn></mrow></math> favoring our model over &#923;CDM, we present compelling evidence for the interplay between local inhomogeneities and modified gravity as the origin of the Hubble tension.

Pakistan

 Mehnaz

Azerbaijan

Jordan

Adnan Malik

Jamshed Khan

Saudi Arabia

Ahdab K. Althukair

Resolving the hubble tension: A unified approach using inhomogeneous Hu-Sawicki <italic>F</italic>( <italic>R</italic>) gravity

In holography, the complexity-momentum correspondence relates the increasing momentum of a point particle falling into an eternal black hole to the rate of growth of the Krylov complexity of the dual boundary state, a conjecture established exactly for the BTZ black hole in AdS at the semiclassical level. We examine possible extensions of the correspondence by considering boundary higher Krylov complexities and Krylov correlators encoding fluctuations and temporal correlations of the spreading quantum state. To this end, we derive exact results for Krylov correlators in quantum systems with $$ \mathfrak{sl}\left(2,\mathbb{R}\right) $$ or Heisenberg-Weyl symmetry and apply them to the complexity-momentum correspondence. We show that certain out-of-time-ordered correlators of two or more Krylov speed operators at different times are proportional to combinations of the proper radial momenta of a particle falling into the BTZ black hole in AdS , evaluated at those times. This represents a first step in the generalization of the original complexity-momentum relation.

E. Alfinito

M. Beccaria

Krylov correlators in $$ \mathfrak{sl}\left(2,\mathbb{R}\right) $$ models: exact results and holographic complexity