<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>

France

G. Aad

Norway

E. Aakvaag

United States

B. Abbott

United Arab Emirates

S. Abdelhameed

Germany

K. Abeling

N.J. Abicht

S.H. Abidi

M. Aboelela

Morocco

A. Aboulhorma

Israel

H. Abramowicz

Y. Abulaiti

Italy

B.S. Acharya

A. Ackermann

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

F. Ahmadov

S. Ahuja

China

X. Ai

G. Aielli

A. Aikot

M. Ait Tamlihat

B. Aitbenchikh

M. Akbiyik

Sweden

T.P.A. Åkesson

A.V. Akimov

Japan

D. Akiyama

N.N. Akolkar

S. Aktas

G.L. Alberghi

Canada

J. Albert

Switzerland

U. Alberti

P. Albicocco

G.L. Albouy

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

W. Alkakhi

C. Allaire

B.M.M. Allbrooke

J.S. Allen

J.F. Allen

P.P. Allport

A. Aloisio

Argentina

F. Alonso

C. Alpigiani

Z.M.K. Alsolami

A. Alvarez Fernandez

M. Alves Cardoso

M.G. Alviggi

M. Aly

Brazil

Y. Amaral Coutinho

A. Ambler

C. Amelung

M. Amerl

C.G. Ames

T. Amezza

D. Amidei

B. Amini

K. Amirie

A. Amirkhanov

Portugal

S.P. Amor Dos Santos

K.R. Amos

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

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

J. D’Hondt

S. Dansana

A. De Moor

M. Delcourt

F. Heyen

Y. Hong

S. Lowette

I. Makarenko

D. Müller

S. Tavernier

M. Tytgat

G.P. Van Onsem

S. Van Putte

D. Vannerom

B. Bilin

B. Clerbaux

A.K. Das

I. De Bruyn

G. De Lentdecker

H. Evard

L. Favart

P. Gianneios

A. Khalilzadeh

F.A. Khan

K. Lee

A. Malara

M.A. Shahzad

L. Thomas

M. Vanden Bemden

C. Vander Velde

P. Vanlaer

M. De Coen

D. Dobur

G. Gokbulut

J. Knolle

L. Lambrecht

D. Marckx

K. Skovpen

N. Van Den Bossche

J. van der Linden

J. Vandenbroeck

L. Wezenbeek

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