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

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

<p>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.</p>

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

<p>A search for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>H</mi></math> production is performed with data from the CMS experiment at the LHC 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> at a proton-proton center-of-mass collision energy of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></mrow></math>. The analysis focuses on the topology of a boosted Higgs boson recoiling against a high-energy photon. The final states of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mrow><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mn>4</mn><mo>ℓ</mo></math> are analyzed. This study examines effective <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>Z</mi><mi>γ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>γ</mi><mi>γ</mi></math> anomalous couplings within the context of an effective field theory. In this approach, the production cross section is constrained to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>σ</mi><mrow><mi>γ</mi><mi>H</mi></mrow></msub><mo>&lt;</mo><mn>16.4</mn><mtext> </mtext><mtext> </mtext><mi>fb</mi></math> at 95% confidence level (CL). Simultaneous constraints on four anomalous couplings involving <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>Z</mi><mi>γ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mi>γ</mi><mi>γ</mi></math> are provided. Additionally, the production rate for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mn>4</mn><mo>ℓ</mo></math> is examined to assess potential enhancements in the Yukawa couplings between light quarks and the Higgs boson. Assuming the standard model values for the Yukawa couplings of the bottom and top quarks, the following simultaneous constraints are obtained: <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>κ</mi><mi>u</mi></msub><mo>=</mo><mo stretchy="false">(</mo><mn>0.0</mn><mo>±</mo><mn>1.5</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mn>3</mn></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>κ</mi><mi>d</mi></msub><mo>=</mo><mo stretchy="false">(</mo><msubsup><mn>0.0</mn><mrow><mo>−</mo><mn>6.8</mn></mrow><mrow><mo>+</mo><mn>6.7</mn></mrow></msubsup><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mn>2</mn></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>κ</mi><mi>s</mi></msub><mo>=</mo><msubsup><mn>0</mn><mrow><mo>−</mo><mn>32</mn></mrow><mrow><mo>+</mo><mn>30</mn></mrow></msubsup></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>κ</mi><mi>c</mi></msub><mo>=</mo><msubsup><mn>0.0</mn><mrow><mo>−</mo><mn>2.8</mn></mrow><mrow><mo>+</mo><mn>2.3</mn></mrow></msubsup></math>. This rules out the hypothesis that up- or down-type quarks in the first or second generation have the same Yukawa couplings as those in the third generation, with a CL greater than 95%.</p>

Armenia

V. Chekhovsky

A. Hayrapetyan

V. Makarenko

A. Tumasyan

Austria

W. Adam

J.W. Andrejkovic

L. Benato

T. Bergauer

S. Chatterjee

K. Damanakis

M. Dragicevic

P.S. Hussain

M. Jeitler

N. Krammer

A. Li

D. Liko

I. Mikulec

J. Schieck

R. Schöfbeck

D. Schwarz

M. Sonawane

W. Waltenberger

C.E. Wulz

Belgium

T. Janssen

H. Kwon

T. Van Laer

P. Van Mechelen

N. Breugelmans

Search for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>H</mi></math> production and constraints on the Yukawa couplings of light quarks to the Higgs boson