Higgs boson production cross-sections via gluon–gluon fusion and vector-boson fusion in proton–proton collisions are measured in the $$H\rightarrow WW^*\rightarrow \ell \nu \ell \nu $$ decay channel. The Large Hadron Collider delivered proton–proton collisions at a centre-of-mass energy of $$13\,\text {TeV}$$ between 2015 and 2018, which were recorded by the ATLAS detector, corresponding to an integrated luminosity of $$140\,\text {fb}^{-1}.$$ The total cross-sections for Higgs boson production by gluon–gluon fusion and vector-boson fusion times the $$H\rightarrow WW^*$$ branching ratio are measured to be $$12.4^{+1.3}_{-1.2}\,\text {pb}$$ and $$0.79^{+0.18}_{-0.16}\,\text {pb},$$ respectively, in agreement with the Standard Model predictions. Higgs boson production is further characterised through measurements of Simplified Template Cross-Sections in a total of fifteen kinematic fiducial regions. A new scheme of kinematic fiducial regions has been introduced to enhance the sensitivity to CP-violating effects in Higgs boson interactions. Both schemes are used to constrain CP-even and CP-odd dimension-six operators in the Standard Model effective field theory

France

G. Aad

Norway

E. Aakvaag

United States

B. Abbott

United Arab Emirates

S. Abdelhameed

Germany

K. Abeling

N. Abicht

S. Abidi

M. Aboelela

Morocco

A. Aboulhorma

Israel

H. Abramowicz

Y. Abulaiti

Italy

United Kingdom

B. Acharya

A. Ackermann

C. Adam Bourdarios

Poland

L. Adamczyk

S. Addepalli

M. Addison

J. Adelman

Türkiye

A. Adiguzel

T. Adye

A. Affolder

Y. Afik

Spain

M. Agaras

A. Aggarwal

Romania

C. Agheorghiesei

Azerbaijan

F. Ahmadov

S. Ahuja

China

X. Ai

G. Aielli

A. Aikot

M. Ait Tamlihat

B. Aitbenchikh

M. Akbiyik

Sweden

T. Åkesson

A. Akimov

Japan

D. Akiyama

N. Akolkar

S. Aktas

G. Alberghi

Canada

J. Albert

P. Albicocco

G. Albouy

S. Alderweireldt

Z. Alegria

Switzerland

M. Aleksa

I. Aleksandrov

C. Alexa

Greece

T. Alexopoulos

F. Alfonsi

M. Algren

M. Alhroob

Czechia

B. Ali

Saudi Arabia

H. Ali

S. Ali

S. Alibocus

South Africa

M. Aliev

G. Alimonti

W. Alkakhi

C. Allaire

B. Allbrooke

J. Allen

P. Allport

A. Aloisio

Argentina

F. Alonso

C. Alpigiani

Z. Alsolami

A. Alvarez Fernandez

M. Alves Cardoso

M. Alviggi

M. Aly

Brazil

Y. Amaral Coutinho

A. Ambler

C. Amelung

M. Amerl

C. Ames

T. Amezza

D. Amidei

B. Amini

K. Amirie

A. Amirkhanov

Portugal

S. Amor Dos Santos

K. Amos

D. Amperiadou

S. An

C. Anastopoulos

T. Andeen

J. Anders

A. Anderson

A. Andreazza

S. Angelidakis

A. Angerami

A. Anisenkov

A. Annovi

C. Antel

E. Antipov

M. Antonelli

F. Anulli

M. Aoki

T. Aoki

Measurements of Higgs boson production via gluon–gluon fusion and vector-boson fusion using $$H\rightarrow WW^*\rightarrow \ell \nu \ell \nu $$ decays in $\textit{pp}$ collisions with the ATLAS detector and their effective field theory interpretations

ATLAS, a general-purpose experiment at the Large Hadron Collider (LHC), makes use of a large internationally-distributed computing infrastructure, including over $$10^6$$ TB of managed data on disk and tape and almost one million simultaneously running CPU cores. Upgrades for the High-Luminosity LHC (HL-LHC) will increase the required computing resources by a factor of 3–4 by the beginning of the 2030s, and by an order of magnitude before the conclusion of data taking at the beginning of the 2040s. These resources are spread over around 100 computing sites worldwide. Efforts are underway within the experiment to evaluate and mitigate various aspects of the environmental impact of the sites, with the additional long-term goal of making recommendations to the sites that will significantly reduce the total expected environmental impact in the HL-LHC era. These efforts take several forms: building awareness in the experiment community, adjusting aspects of the computing policy, and modifications of data center configurations, either in ways that take advantage of particular features of ATLAS workloads or in generic ways that reduce the environmental impact of the computing resources. This paper describes the ongoing investigations and approaches that have already provided useful and actionable outcomes.

C. Bourdarios

M. Tamlihat

U. Alberti

A. Fernandez

M. Cardoso

Y. Coutinho

S. Santos

The environmental impact, carbon emissions and sustainability of computing in the ATLAS experiment

This study explores the realization of nonminimally coupled Higgs inflation in the context of no-scale supergravity, investigates the formation of primordial black holes, and examines the potential for observable proton decay within the framework of the R-symmetric $\textit{SU}$(5) model. For inflation, both single and multifield scenarios are investigated. The prediction of the single-field model for the tensor-to-scalar ratio, $\textit{r}$, is approximately $$10^{-3}$$ , and the scalar spectral index falls within Planck’s 1 $$\sigma $$ range. The running of the scalar spectral index, $$-{dn_{s}}/{d\ln {k}}$$ , is approximately $$10^{-4}$$ . A realistic scenario of reheating and non-thermal leptogenesis is employed with reheat temperature $$T_r\sim 10^9$$ GeV. In the multifield case, we mainly focus on Primordial Black Holes (PBHs) and Gravitational Waves (GWs). In this inflationary framework, we demonstrate how a suitable choice of parameters can result in an enhanced scalar power spectrum, leading to the production of primordial black holes (PBHs) capable of fully accounting for dark matter. We also show that this scenario leads to Scalar Induced Gravitational Waves (SIGW) which can be detected in current and future GW detectors. We explore different proton decay channels to look for observable predictions for the next-generation proton decay experiments Hyper-K and DUNE consistent with gauge coupling unification and cosmological bounds.

Pakistan

Nadir Ijaz

Maria Mehmood

Mansoor Ur Rehman

The stochastic gravitational-wave background from primordial black holes and observable proton decay in R-symmetric $\textit{SU}$(5) Inflation

Exploring exotic matter around black holes (BHs) under different conditions, using equations of state and astrophysical observational data from BHs, may deepen our understanding of the nature of dark matter and theories of gravity. In the present work, we first briefly introduce a BH solution surrounded by a dust field in <italic>f</italic>( <italic>R, T</italic>) gravity and study the properties of the horizon around the BH. We investigate scalar invariants of the spacetime geometry, such as the Ricci scalar, the square of the Ricci tensor, and the Kretchman scalar. We also study the circular motion of test particles. Additionally, we investigate the effects of the dust field on the innermost stable circular orbits (ISCOs) and the particle&#8217;s energy and angular momentum at the ISCO. Moreover, we investigate particle oscillations near ISCO around the BH and calculate the frequencies of Keplerian orbits and vertical oscillations. As an astrophysical application of the studies, we study quasiperiodic oscillations (QPOs) in various QPO models. Finally, we obtain constraints on the dust field and BH parameters using a Monte Carlo Markov Chain (MCMC) simulation across the multidimensional parameter space for the microquasars GRO J1655-40 &amp; GRS 1915-105, the Milky Way, and the M82 X-1 galaxy.

Uzbekistan

Abubakir Shermatov

Javlon Rayimbaev

Sardor Murodov

Bushra Majeed

Inomjon Ibragimov

Bahran Shermatov

Erkaboy Davletov

Ikram Davletov

Circular motion and QPOs near BHs surrounded by dust fields in <italic>f</italic>( <italic>R, T</italic>) gravity

In this study, we investigate the inflationary dynamics of Rainbow <italic>f</italic>( <italic>R</italic>) gravity characterized by <italic>f</italic>( <italic>R</italic>)&#8239;&#8771;&#8239; <italic>&#945;Rn</italic>, with the rainbow deformation <math altimg='si8.svg'><mrow><mover accent='true'><mi>f</mi><mo>&#732;</mo></mover><mrow><mo>(</mo><mi>H</mi><mo>)</mo></mrow><mo>&#8764;</mo><msup><mi>H</mi><mi>&#955;</mi></msup></mrow></math> and <math altimg='si9.svg'><mrow><mover accent='true'><mi>g</mi><mo>&#732;</mo></mover><mo linebreak='goodbreak'>=</mo><mn>1</mn></mrow></math>. The effects of the rainbow parameter <italic>&#955;</italic> and the curvature exponent <italic>n</italic> on inflationary observables are analyzed under the Atacama Cosmology Telescope (ACT) constraint 0.9709&#8239;&lt;&#8239; <italic>n<inf>s</inf></italic>&#8239;&lt;&#8239;0.9777. Numerical results reveal a clear correlation among <italic>n, &#955;</italic>, and the tensor-to-scalar ratio <italic>r</italic>, such that decreasing <italic>n</italic> corresponds to increasing <italic>&#955;</italic>, accompanied by a growth in <italic>r</italic> within observational limits. Negative values of <italic>&#955;</italic> (typically for <italic>n</italic>&#8239;&#8776;&#8239;3) yield a quasi&#8211;de Sitter inflationary phase with a nearly constant Hubble parameter and suppressed tensor modes, while positive <italic>&#955;</italic> (for <italic>n</italic>&#8239;&#8818;&#8239;2.2) drive a quintessence&#8211;like inflationary regime with enhanced expansion and a time-dependent curvature. Using power&#8211;law solutions <italic>a</italic>( <italic>t</italic>)&#8733; <italic>tp</italic>, we relate the expansion exponent to the number of <italic>e</italic>-folds <italic>N</italic>&#8239;&#8771;&#8239;50&#8211;60. Small deviations between the matter and effective equations of state indicate a mild breaking of <math altimg='si10.svg'><mrow><msub><mi>w</mi><mi>e</mi></msub><mo linebreak='goodbreak'>=</mo><mi>w</mi></mrow></math>, suggesting the emergence of matter&#8211;like behavior within the quintessence&#8211;like inflationary field. At low curvature, we further show that a logarithmic Nojiri&#8211;Odintsov correction <italic>f</italic>( <italic>R</italic>)&#8239;&#8771;&#8239; <italic>&#945;</italic>&#8242;ln&#8201;( <italic>R</italic>/ <italic>&#956;</italic> 2) naturally dominates the dynamics, giving rise to a late&#8211;time quintessence phase ( <math altimg='si11.svg'><mrow><mo>&#8722;</mo><mn>1</mn><mo linebreak='goodbreak'>&lt;</mo><msub><mi>w</mi><mi>e</mi></msub><mo linebreak='goodbreak'>&lt;</mo><mo>&#8722;</mo><mn>1</mn><mo linebreak='goodbreak'>/</mo><mn>3</mn></mrow></math> for <math altimg='si12.svg'><mrow><mi>&#955;</mi><mo linebreak='goodbreak'>&gt;</mo><mo>&#8722;</mo><mn>1</mn></mrow></math>) that asymptotically approaches a de Sitter attractor ( <math altimg='si13.svg'><mrow><msub><mi>w</mi><mi>e</mi></msub><mo>&#8594;</mo><mo>&#8722;</mo><mn>1</mn></mrow></math> as &#1013; <inf>1</inf>&#8239;&#8594;&#8239;0 or <math altimg='si14.svg'><mrow><mi>&#955;</mi><mo linebreak='goodbreak'>=</mo><mo>&#8722;</mo><mn>1</mn></mrow></math>). Thus, the combined <italic>Rn</italic> and logarithmic contributions provide a unified geometric framework in which early&#8211;time inflation and late&#8211;time cosmic acceleration naturally arise from different curvature regimes of Rainbow <italic>f</italic>( <italic>R</italic>) gravity, consistent with ACT observational data.

A.I. Keskin

Rainbow <italic>f</italic>( <italic>R</italic>) Inflation: de Sitter-Quintessence Phases

A measurement of the top-quark pole mass $$ {m}_t^{\textrm{pole}} $$ is presented in $$ t\overline{t} $$ events with an additional jet, $$ t\overline{t} $$ + 1-jet, produced in $\textit{pp}$ collisions at $$ \sqrt{s}=13 $$ TeV. The data sample, recorded with the ATLAS experiment during Run 2 of the LHC, corresponds to an integrated luminosity of 140 fb . Events with one electron and one muon of opposite electric charge in the final state are selected to measure the $$ t\overline{t} $$ + 1-jet differential cross-section as a function of the inverse of the invariant mass of the $$ t\overline{t} $$ + 1-jet system. Iterative Bayesian Unfolding is used to correct the data to enable comparison with fixed-order calculations at next-to-leading-order accuracy in the strong coupling. The process $$ pp\to t\overline{t}j\left(2\to 3\right) $$ , where top quarks are taken as stable particles, and the process $$ pp\to b\overline{b}{l}^{+}\nu {l}^{-}\overline{\nu}j\left(2\to 7\right) $$ , which includes top-quark decays to the dilepton final state and off-shell effects, are considered. The top-quark mass is extracted using a $\textit{χ}$ fit of the unfolded normalized differential cross-section distribution. The results obtained with the 2 → 3 and 2 → 7 calculations are compatible within theoretical uncertainties, providing an important consistency check. The more precise determination is obtained for the 2 $\textit{→}$ 3 measurement: $$ {m}_t^{\textrm{pole}}=170.7\pm 0.3\left(\textrm{stat}.\right)\pm 1.4\left(\textrm{syst}.\right)\pm 0.3\left(\textrm{scale}\right)\pm 0.2\left(\textrm{PDF}\oplus {\alpha}_{\textrm{S}}\right) $$ GeV, which is in good agreement with other top-quark mass results.

Measurement of the top-quark pole mass in dileptonic $$ t\overline{t} $$ + 1-jet events at $$ \sqrt{s}=13 $$ TeV with the ATLAS experiment

A search for the dimuon decay of the Higgs boson is presented based on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi></math> collision data recorded by ATLAS during Run 3 of the Large Hadron Collider, corresponding to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>165</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>fb</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math> at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>13.6</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></mrow></math>. To enhance the sensitivity, the results are combined with those from Run 2. An excess of events over the background is observed with a significance of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3.4</mn><mi>σ</mi></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2.5</mn><mi>σ</mi></math> expected). The best-fit signal strength is <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>μ</mi><mo>=</mo><mn>1.4</mn><mo>±</mo><mn>0.4</mn></mrow></math>. This result provides evidence for the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>H</mi><mo stretchy="false">→</mo><mi>μ</mi><mi>μ</mi></mrow></math> decay with ATLAS data and offers a direct probe of the Higgs-boson Yukawa coupling to second-generation fermions.

N.J. Abicht

S.H. Abidi

B.S. Acharya

S.V. Addepalli

M.J. Addison

A.A. Affolder

M.N. Agaras

T.P.A. Åkesson

A.V. Akimov

N.N. Akolkar

G.L. Alberghi

G.L. Albouy

Z.L. Alegria

CERN

I.N. Aleksandrov

H.M.J. Ali

S.W. Alibocus

B.M.M. Allbrooke

J.S. Allen

J.F. Allen

P.P. Allport

Z.M.K. Alsolami

M.G. Alviggi

C.G. Ames

S.P. Amor Dos Santos

K.R. Amos

J.K. Anders

A.C. Anderson

A.V. Anisenkov

Evidence for the Dimuon Decay of the Higgs Boson in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi></math> Collisions with the ATLAS Detector

The analysis of the latest most accurate experimental data on neutron decay for the possibility of the existence of the right vector boson <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mi>W</mi><mi>R</mi></msub></mrow></math> is carried out. As a result of the analysis within the framework of the left-right symmetric model, it was found that there is an indication of the existence of the right vector boson <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mi>W</mi><mi>R</mi></msub></mrow></math> with a mass of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mi>M</mi><mrow><msub><mi>W</mi><mi>R</mi></msub></mrow></msub><mo>=</mo><msubsup><mn>304</mn><mrow><mo>−</mo><mn>20</mn></mrow><mrow><mo>+</mo><mn>24</mn></mrow></msubsup><mtext> </mtext><mtext> </mtext><mi>GeV</mi></mrow></math>, and a mixing angle with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mi>W</mi><mi>L</mi></msub></mrow></math>: <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>ζ</mi><mo>=</mo><mo>−</mo><mn>0.039</mn><mo>±</mo><mn>0.0</mn><mn>1</mn><mn>4</mn></mrow></math>. It is shown that this result does not contradict the experiments at colliders to search for a hypothetical vector boson. In addition, it is shown that it is possible to describe the effects of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math> violation in decays of neutral <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>K</mi></math>-mesons and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi></math>-mesons using the parameters of the extended left-right symmetric model obtained from neutron decay, i.e., squared masses of the left and right bosons ratio and the mixing angle. The formation of baryon-lepton asymmetry of the Universe is considered within the framework of the left-right model of weak interaction with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math> violation.

Russia

A.P. Serebrov

O.M. Zherebtsov

A.K. Fomin

R.M. Samoilov

N.S. Budanov

Analysis of experimental data on neutron decay for the possibility of the existence of the right vector boson <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>W</mi><mi>R</mi></msub></math>

The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>R</mi><mn>2</mn></msup></math>-Higgs inflation is one of the simplest yet best-fit models consistent with Planck data. The higher spectral index <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>n</mi><mi>s</mi></msub></math> recently reported by the combined cosmic microwave background (CMB) data from the Atacama Cosmology Telescope (ACT), South Pole Telescope (SPT), and Planck, along with baryonic acoustic oscillation data from the Dark Energy Spectroscopic Instrument (DESI), disfavors the single-field-like regime of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>R</mi><mn>2</mn></msup></math>-Higgs inflation at approximately <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>σ</mi></math>. Following a doubly covariant formalism, we show that the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>R</mi><mn>2</mn></msup></math>-Higgs inflation, when modified by a dimension-six <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>R</mi><mn>3</mn></msup></math> term, can account for the high <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>n</mi><mi>s</mi></msub></math> reported by <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>CMB</mi><mo>+</mo><mi>BAO</mi></mrow></math>. In this regard, we find that preheating may play a pivotal role. We also show that if the nonminimal coupling between the Ricci scalar <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>R</mi></math> and the Higgs field is <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><mn>10</mn><mo stretchy="false">)</mo></math>, then preheating via the production of Higgs quanta may help explain the reported observations.

India

Tanmoy Modak

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>R</mi><mn>2</mn></msup></math>-Higgs inflation: <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>R</mi><mn>3</mn></msup></math> contribution and preheating after ACT and SPT data