In this paper, we study non-supersymmetric $\textit{AdS}$ × $\textit{S}$ vacuua of $\textit{O}$(16) × $\textit{O}$(16) heterotic theory on a string scale $\textit{T}$ background, which are parameterized by a pair of flux integers. Adding the one-loop scalar potential to the effective theory contributes positively to the cosmological constant, but we find that there is no uplift to de Sitter for any values of the fluxes. We study the fluctuations around these vacua and show that all scalar and tensor modes from the six-dimensional effective theory lie above the Breitenlohner-Freedman bound. The moduli coming from the torus compactification will also be above the bound, at least for a large range of fluxes.

United States

Daniel Robbins

Hassaan Saleem

$\textit{O}$(16) $\textit{× O}$(16) heterotic theory on $\textit{AdS}$ 3 $\textit{× S}$ 3 $\textit{× T}$ 4

A search for signatures of a dark analog to quantum chromodynamics is performed. The analysis targets long-lived dark mesons that decay into standard-model particles, with a high branching fraction of the dark mesons decaying into muons. The dark mesons are formed by the hadronisation of dark partons, which are produced by a decay of the Higgs boson. The search is performed using a data set corresponding to an integrated luminosity of 41.6 fb , which was collected in proton-proton collisions at $$ \sqrt{s}=13 $$ TeV by the CMS experiment at the CERN LHC in 2018 using non-prompt muon triggers. The search is based on resonant muon pair signatures. Machine-learning techniques are employed in the analysis, utilising boosted decision trees to discriminate between signal and background. No significant excess is observed above the standard model expectation. Upper limits on the branching fraction of the Higgs boson decaying to dark partons are determined to be as low as 10 at 95% confidence level, surpassing and extending the existing limits on models with dark $$ \overset{\sim }{\upomega} $$ mesons for mean proper decay lengths of less than 500 mm and for $$ \overset{\sim }{\upomega} $$ masses down to 0.3 GeV. First limits are set for extended dark-shower models with two dark flavours that contain dark photons, probing their masses down to 0.33 GeV.

Armenia

A. Hayrapetyan

V. Makarenko

A. Tumasyan

Austria

W. Adam

J. Andrejkovic

L. Benato

T. Bergauer

M. Dragicevic

C. Giordano

P. Hussain

M. Jeitler

N. Krammer

A. Li

D. Liko

M. Matthewman

I. Mikulec

J. Schieck

D. Schwarz

R. Schöfbeck

M. Shooshtari

M. Sonawane

W. Waltenberger

C.E. Wulz

Belgium

T. Janssen

H. Kwon

D. Ocampo Henao

T. Laer

P. Mechelen

J. Bierkens

N. Breugelmans

J. D’Hondt

S. Dansana

A. Moor

M. Delcourt

F. Heyen

Y. Hong

P. Kashko

S. Lowette

I. Makarenko

D. Müller

J. Song

S. Tavernier

M. Tytgat

G. Onsem

S. Putte

D. Vannerom

B. Bilin

B. Clerbaux

A. Das

I. Bruyn

G. Lentdecker

H. Evard

L. Favart

P. Gianneios

A. Khalilzadeh

F. Khan

A. Malara

M. Shahzad

L. Thomas

M. Bemden

C. Vander Velde

P. Vanlaer

F. Zhang

M. Coen

D. Dobur

G. Gokbulut

J. Knolle

D. Marckx

K. Skovpen

A. Tomaru

N. Bossche

J. Linden

J. Vandenbroeck

L. Wezenbeek

S. Bein

A. Benecke

A. Bethani

G. Bruno

A. Cappati

J. De Favereau De Jeneret

C. Delaere

F. Gameiro Casalinho

A. Giammanco

A. Guzel

V. Lemaitre

J. Lidrych

P. Malek

P. Mastrapasqua

S. Turkcapar

Brazil

G. Alves

M. Barroso Ferreira Filho

E. Coelho

C. Hensel

T. Menezes De Oliveira

C. Mora Herrera

P. Rebello Teles

M. Soeiro

E. Tonelli Manganote

A. Vilela Pereira

W. Aldá Júnior

Search for low-mass hidden-valley dark showers with non-prompt muon pairs in proton-proton collisions at $$ \sqrt{s}=13 $$ TeV

In this work, we investigate exact black string solutions in the context of $\textit{f}$($\textit{R}$, $\textit{T}$) gravity. Adopting the specific form $$f(R,T) = R + 2\chi T$$ , we consider an anisotropic Kiselev fluid as the matter content and obtain static cylindrical solutions, which are then extended to the rotating case through a suitable coordinate transformation. The influence of the quintessence state parameter $$w_q$$ and the matter–geometry coupling constant $$\chi $$ on the geometry is analyzed. We examine the weak, null, and strong energy conditions, identifying the regions in the parameter space where they are satisfied. Furthermore, we apply the Hamilton–Jacobi method to study the tunneling of scalar particles across the event horizon and derive the corresponding Hawking temperature. The thermodynamic stability of the solutions is investigated by computing the heat capacity, and the conditions for phase transitions are discussed. The results provide a characterization of black strings in $\textit{f}$($\textit{R}$, $\textit{T}$) gravity surrounded by quintessence, highlighting the combined effects of anisotropic matter and modified gravity on their physical properties.

L. Santos

L. Barbosa

C. Barros

Kiselev black strings in $\textit{f}$($\textit{R}$, $\textit{T}$) gravity

This research paper explores the structure of hypothetical compact stars, known as strange stars, within the framework of a novel modified theory of gravity called $$f(R,\Sigma ,T)$$ gravity. This theory extends General Relativity by making gravity dependent not only on the Ricci curvature scalar $\textit{R}$ but also on a torsion scalar $$\Sigma $$ and the trace of the matter energy–momentum tensor $\textit{T}$. This introduces a richer coupling between geometry and matter. The study presents a highly exotic, multi-layered stellar model composed of five distinct regions, each with a unique equation of state and geometric properties. The model features a dark-energy-like core with powerful repulsive gravity (anti-gravity), surrounded by successive layers of dust, exotic radiation, and a stiff matter crust, all enveloped by a standard Schwarzschild vacuum exterior. A key finding is the prevalence of negative energy densities and pressures in several layers, a hallmark of exotic matter. These configurations, enabled by the $$f(R,\Sigma ,T)$$ framework, lead to repulsive gravitational effects that radically alter the star’s internal equilibrium. The analysis demonstrates how additional geometry-driven forces within this theory can support such exotic structures, potentially preventing gravitational collapse and resulting in a stable, non-singular object. This work demonstrates that $$f(R,\Sigma ,T)$$ gravity allows for new and complex classes of compact objects with stratified, exotic matter distributions, whose properties and observational signatures would differ significantly from those predicted by standard General Relativity.

Egypt

M. Bakry

Saudi Arabia

A. Eid

Tahia Dabash

The impact of $$f(R,\Sigma ,T)$$ gravity on strange star structure

An analysis of the flavour structure of dimension-6 effective field theory (EFT) operators in multilepton final states is presented, focusing on the interactions of quarks with Z bosons. For the first time, the flavour structure of these operators is disentangled by simultaneously probing the interactions with different quark generations. The analysis targets the associated production of a top quark pair and a Z boson, as well as diboson processes in final states with at least three leptons, which can be electrons or muons. The data were recorded by the CMS experiment in the years 2016–2018 in proton-proton collisions at a centre-of-mass energy of 13 TeV and correspond to an integrated luminosity of 138 fb . Consistency with the standard model of particle physics is observed and limits are set on the selected Wilson coefficients, split into couplings to light- and heavy-quark generations.

L. Lambrecht

H. Brandao Malbouisson

Probing the flavour structure of dimension-6 EFT operators in multilepton final states in proton-proton collisions at $$ \sqrt{s}=13 $$ TeV

<p>Measurements of the spin correlation coefficients in the beam basis are presented for top quark-antiquark (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi><mover accent="true"><mi>t</mi><mo stretchy="false">¯</mo></mover></math>) systems produced in proton-proton collisions at <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> collected by the CMS experiment in 2016–2018, and corresponding to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>138</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>. The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi><mover accent="true"><mi>t</mi><mo stretchy="false">¯</mo></mover></math> system is reconstructed from final states containing an electron or muon and jets. Together with the previously reported results in the helicity basis, these measurements are used to decompose the system into the Bell and spin eigenstates in various kinematic regions. The spin correlation coefficients are also used to evaluate properties of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi><mover accent="true"><mi>t</mi><mo stretchy="false">¯</mo></mover></math> quantum state, such as the purity, von Neumann entropy, and entanglement. All results are consistent with standard model predictions.</p>

P.S. Hussain

T. Van Laer

P. Van Mechelen

A. De Moor

G.P. Van Onsem

S. Van Putte

A.K. Das

I. De Bruyn

G. De Lentdecker

F.A. Khan

M.A. Shahzad

A. Sharma

M. Vanden Bemden

M. De Coen

K. Kaspar

D. Kavtaradze

A.M. Tomaru

N. Van Den Bossche

J. van der Linden

H. Aarup Petersen

A.O. Guzel

G.A. Alves

D. Matos Figueiredo

E.J. Tonelli Manganote

W.L. Aldá Júnior

Characterization of the quantum state of top quark pairs produced in proton-proton collisions at <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> using the beam and helicity bases

We study spacetime four-point functions of chiral primary operators for superstrings propagating in AdS $\textit{× S}$ $\textit{× T}$ from the worldsheet perspective, allowing for external states with arbitrary spectral flow charges. We work at small boundary cross-ratio and consider both extremal (supersymmetry-protected) and non-extremal configurations. The string correlators involve a non-trivial integration over the worldsheet moduli, and we demonstrate how the exchange of short and long strings is encoded in distinct integration regions. We interpret our results in terms of the operator product expansion in the boundary theory, and make explicit the precise matching with the available data for the relevant holographic correlators.

Argentina

Emiliano Barone

Sergio Iguri

Nicolas Kovensky

Julián Toro

Superstring four-point functions in AdS3 $\textit{× S}$ 3 $\textit{× T}$ 4

<p>The energy-momentum tensor form factor <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></math> is finite and negative in hadronic models and lattice QCD when only strong forces are included. However, when electromagnetic forces are considered, the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></math> of charged hadrons undergoes a dramatic change: at small <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi></math>, it changes sign and diverges like <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mo>/</mo><msqrt><mrow><mo>−</mo><mi>t</mi></mrow></msqrt></math> as shown for the proton in the classical model by Białynicki-Birula based on residual nuclear forces which can be understood as a mean field approach. We construct an analogous neutron model and show that this framework accurately explains the electromagnetic proton-neutron mass difference. We demonstrate that, after appropriately rescaling the residual nuclear forces, the model can reproduce lattice data on the nucleon <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></math> up to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mo>−</mo><mi>t</mi><mo stretchy="false">)</mo><mo>≲</mo><mn>1</mn><mtext> </mtext><mtext> </mtext><msup><mi>GeV</mi><mn>2</mn></msup></mrow></math> as well as QED effects. Based on this realistic model description, we show that the proton and neutron <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></math> form factors are practically indistinguishable down to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mo>−</mo><mi>t</mi><mo stretchy="false">)</mo><mo>≈</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup><mtext> </mtext><mtext> </mtext><msup><mi>GeV</mi><mn>2</mn></msup></mrow></math>, far below what can currently be accessed experimentally. We conclude that in the foreseeable future the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></math> form factors of the proton and neutron will practically look the same in experiments and phenomenology.</p>

Andrea Mejia

Peter Schweitzer

Energy-momentum tensor form factor <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>D</mi><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></mrow></math> of the proton and neutron

Measurements of properties of top quark-antiquark pair production in association with a W boson in proton-proton collisions at a center-of-mass energy of 13 TeV are presented, using a data sample corresponding to an integrated luminosity of 138 fb , recorded by the CMS experiment at the CERN LHC. Events are selected based on the presence of either two leptons with the same electric charge or three leptons, and multiple jets and b-tagged jets. We present measurements of differential production cross sections as a function of kinematic variables sensitive to different aspects of the process modeling, using a multivariate discriminator in the two-lepton selection region and a simple selection-based method in the three-lepton region. The normalized cross section measurements are generally consistent with the standard model expectations, while we observe larger values compared to the expectations in the absolute cross section measurements, consistent with previous inclusive cross section measurements. In addition, we measure the leptonic charge asymmetry of this process, obtaining an observed value of $$ {A}_c^{\ell }=-{0.19}_{-0.18}^{+0.16} $$ , consistent with the expectation of $\textit{−}$0.085 $\textit{±}$ 0.006 predicted by next-to-leading order simulations.

W. Carvalho

Measurements of $$ \textrm{t}\overline{\textrm{t}}\textrm{W} $$ differential cross sections and the leptonic charge asymmetry at $$ \sqrt{s}=13 $$ TeV

We propose boundary terms for the action of the NS sector of supergravity on $\textit{M}$ × $\textit{S}$ × $\textit{T}$ spacetimes — where $\textit{M}$ is an AdS or a linear dilaton background — that render the Brown-York stress tensor and the on-shell action finite. For AdS backgrounds, we show that the on-shell action yields a free energy with chemical potentials determined by the $\textit{B}$-field. TsT (T-duality + shift + T-duality) transformations of these backgrounds generate classes of linear dilaton backgrounds distinguished by their boundary conditions. Among them, there is one class of backgrounds that reproduces features of the single-trace $$ T\overline{T} $$ deformation. These backgrounds have additional chemical potentials that can be turned off by large gauge transformations of the $\textit{B}$-field. We show that the Brown-York stress tensor of these backgrounds reproduces the energies and the trace flow equation of $$ T\overline{T} $$ -deformed CFTs. We also show that the on-shell action matches the $$ T\overline{T} $$ partition function and discuss the interpretation of these results.

China

Luis Apolo

The on-shell action of supergravity & the $\textit{B}$-side of TsT and single-trace $$ T\overline{T} $$