This paper presents a comprehensive analysis of junction conditions for gluing different $\textit{f}$($\textit{R}$) gravitational theories across a non-null hypersurface. Using the variational approach, we systematically derive the junction conditions for both general $\textit{f}$($\textit{R}$) theories and the special case of Einstein gravity, for comparison. We demonstrate that when joining two distinct $\textit{f}$($\textit{R}$) theories, the junction conditions require continuity of $$\partial f(R)/\partial R$$ , the extrinsic curvature $$K_{\mu \nu }$$ , while allowing for discontinuities in the Ricci Scalar $\textit{R}$. Furthermore, we establish the equivalence between Jordan and Einstein frame formulations through careful treatment of conformal transformations; Our results reveal that different $\textit{f}$($\textit{R}$) theories can be consistently matched provided specific relations between their functional forms and geometric quantities are satisfied at the interface.

Iran

Amin Aalipour

Nima Khosravi

Gluing different gravitational models: $\textit{f}$($\textit{R}$) case

We develop the ordinary differential equation–integrable model correspondence for the higher-order Mathieu equation arising from the quantum Seiberg-Witten curve of the pure <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mi>U</mi><mo stretchy="false">(</mo><mi>r</mi><mo>+</mo><mn>1</mn><mo stretchy="false">)</mo></math> <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>2</mn></math> supersymmetric Yang-Mills theory. From the subdominant solutions, we construct the Q and Y systems and derive the corresponding thermodynamic Bethe ansatz (TBA) equations. The dependence of the moduli parameters is found to be encoded in the boundary conditions of the Y functions at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>θ</mi><mo stretchy="false">→</mo><mo>−</mo><mi>∞</mi></math>. From these boundary data, we derive an analytic expression for the effective central charge, which also governs the subleading contribution in the large-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>θ</mi></math> expansion of the TBA equations. Finally, we compare the large-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>θ</mi></math> expansion of the Q function derived from the TBA equations with that obtained from the WKB method, which yields analytic agreement at subleading order and precise numerical agreement at the higher-order corrections.

China

Feiyu Peng

Hongfei Shu

Thermodynamic Bethe ansatz equations for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mi>U</mi><mo stretchy="false">(</mo><mi>r</mi><mo>+</mo><mn>1</mn><mo stretchy="false">)</mo></math> quantum Seiberg-Witten curve: Higher-order Mathieu equation

A central difficulty in the physics of traversable wormholes is the requirement of exotic matter, which arises from the violation of the null energy condition within classical general relativity. This motivates the study of modified gravitational frameworks and quantum-gravitational corrections that collectively reshape the effective stress-energy sector. In this work, we develop a unified construction combining three physically well-motivated ingredients: noncommutative geometry (NCG), the generalized uncertainty principle (GUP), and <italic>f</italic>( <italic>R, T</italic>) modified gravity with <math altimg='si15.svg'><mrow><mi>f</mi><mo>(</mo><mi>R</mi><mo>,</mo><mi>T</mi><mo>)</mo><mo>=</mo><mi>R</mi><mo linebreak='goodbreak'>+</mo><mn>2</mn><mi>&#955;</mi><mi>T</mi></mrow></math>. We adopt the matter Lagrangian <math altimg='si16.svg'><mrow><msub><mi mathvariant='script'>L</mi><mi>m</mi></msub><mo linebreak='goodbreak'>=</mo><mo>&#8722;</mo><mi>&#961;</mi></mrow></math> and derive the corresponding modified field equations carefully, specifying the explicit form of the effective stress-energy tensor. The NCG Gaussian matter distribution regularises the source profile over a minimal length scale <math altimg='si17.svg'><msqrt><mi>&#952;</mi></msqrt></math> and may reduce the amount of exotic matter required near the throat, while the GUP introduces quantum-gravitational corrections to the energy density and pressure at sub-Planckian scales. We perform a complete derivation of the wormhole shape function, writing it as <math altimg='si18.svg'><mrow><mi>b</mi><mrow><mo>(</mo><mi>r</mi><mo>)</mo></mrow><mo linebreak='goodbreak'>=</mo><msub><mi>b</mi><mrow><mrow><mi mathvariant='normal'>N</mi></mrow><mi>C</mi><mi>G</mi></mrow></msub><mrow><mo>(</mo><mi>r</mi><mo>)</mo></mrow><mo linebreak='goodbreak'>+</mo><msub><mi>b</mi><mrow><mrow><mi mathvariant='normal'>G</mi></mrow><mi>U</mi><mi>P</mi></mrow></msub><mrow><mo>(</mo><mi>r</mi><mo>)</mo></mrow></mrow></math>, where each contribution is obtained through an explicit integration of the corresponding source term. The throat conditions, flare-out criterion, and asymptotic flatness are verified analytically, and the key limiting cases <italic>&#946;</italic>&#8239;&#8594;&#8239;0, <italic>&#955;</italic>&#8239;&#8594;&#8239;0, and <italic>&#952;</italic>&#8239;&#8594;&#8239;0 are checked for consistency. An analysis of the null energy condition shows that the NEC violation is spatially localised near the throat owing to the Gaussian suppression provided by the NCG matter distribution, and the volume integral quantifier is evaluated with the <italic>f</italic>( <italic>R, T</italic>) coupling included explicitly. The effective potential for axial perturbations is derived and used to compute the gravitational wave echo time delay, which provides potential phenomenological signatures relevant for future gravitational-wave echo searches.

Azerbaijan

Pakistan

Allah Ditta

Noncommutative wormholes with generalized uncertainty principle in <italic>f</italic>( <italic>R, T</italic>) gravity: Energy conditions and gravitational wave echo time delay

Right-handed lepton flavor mixing in the left-right symmetric model directly affects the production and decay of heavy Majorana neutrinos <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mi>R</mi></msub></math>, yet its impact on collider searches remains less explored. Using a deep neural network, we analyze the Keung-Senjanović process <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>p</mi><mi>p</mi><mo stretchy="false">→</mo><msub><mrow><mi>W</mi></mrow><mrow><mi>R</mi></mrow></msub><mo stretchy="false">→</mo><msub><mrow><mo>ℓ</mo></mrow><mrow><mi>α</mi></mrow></msub><msub><mrow><mi>N</mi></mrow><mrow><mi>R</mi></mrow></msub><mo stretchy="false">→</mo><msub><mrow><mo>ℓ</mo></mrow><mrow><mi>α</mi></mrow></msub><msub><mrow><mo>ℓ</mo></mrow><mrow><mi>β</mi></mrow></msub><mi>j</mi><mi>j</mi></mrow></math> with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mo>ℓ</mo></mrow><mrow><mi>α</mi><mo>,</mo><mi>β</mi></mrow></msub><mo>=</mo><mi>e</mi></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>μ</mi></mrow></math> at LHC Run 2 and the HL-LHC, considering both same-sign and opposite-sign dilepton channels. We adopt three benchmark mixing scenarios: unmixed, maximal mixing, and Pontecorvo-Maki-Nakagawa-Sakata (PMNS)-like. In the unmixed scenario, the deep neural network improves the expected significance over the cut-based analyses performed by ATLAS, leading to stronger expected sensitivities. For the combined <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>ℓ</mo><mo>ℓ</mo></math> analysis, the HL-LHC is projected to reach <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><msub><mi>W</mi><mi>R</mi></msub></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><msub><mi>N</mi><mi>R</mi></msub></msub></math> values up to 6.7 (6.3) and 4.4 (4.1) TeV, respectively, under maximal (PMNS-like) mixing. For representative mass benchmarks, our analysis indicates that LHC Run 2 can test a significant portion of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">|</mo><msub><mrow><mi>V</mi></mrow><mrow><mi>e</mi><mn>1</mn></mrow></msub><mo stretchy="false">|</mo><mtext>−</mtext><mo stretchy="false">|</mo><msub><mrow><mi>V</mi></mrow><mrow><mi>μ</mi><mn>1</mn></mrow></msub><mo stretchy="false">|</mo></mrow></math> plane, and the HL-LHC could probe even smaller mixing values, including the corresponding benchmark points for both the maximal and PMNS-like patterns. Finally, we investigate complementarities with low-energy charged lepton flavor-violation processes, where future searches can overlap with or exceed the LHC reach.

Jin-Man Cai

Gang Li

Probing lepton flavor mixing in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>W</mi><mi>R</mi></msub></math> searches with machine learning at the LHC

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

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.

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

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