Search for γ H production and constraints on the Yukawa couplings of light quarks to the Higgs boson

A search for <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mi>γ</a:mi> <a:mi>H</a:mi> </a:math> production is performed with data from the CMS experiment at the LHC corresponding to an integrated luminosity of <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"> <c:mn>138</c:mn> <c:mtext> </c:mtext> <c:mtext> </c:mtext> <c:msup> <c:mi>fb</c:mi> <c:mrow> <c:mo>−</c:mo> <c:mn>1</c:mn> </c:mrow> </c:msup> </c:math> at a proton-proton center-of-mass collision energy of <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"> <e:mrow> <e:mn>13</e:mn> <e:mtext> </e:mtext> <e:mtext> </e:mtext> <e:mi>TeV</e:mi> </e:mrow> </e:math> . The analysis focuses on the topology of a boosted Higgs boson recoiling against a high-energy photon. The final states of <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"> <g:mi>H</g:mi> <g:mo stretchy="false">→</g:mo> <g:mrow> <g:mi>b</g:mi> <g:mover accent="true"> <g:mi>b</g:mi> <g:mo stretchy="false">¯</g:mo> </g:mover> </g:mrow> </g:math> and <l:math xmlns:l="http://www.w3.org/1998/Math/MathML" display="inline"> <l:mi>H</l:mi> <l:mo stretchy="false">→</l:mo> <l:mn>4</l:mn> <l:mo>ℓ</l:mo> </l:math> are analyzed. This study examines effective <o:math xmlns:o="http://www.w3.org/1998/Math/MathML" display="inline"> <o:mi>H</o:mi> <o:mi>Z</o:mi> <o:mi>γ</o:mi> </o:math> and <q:math xmlns:q="http://www.w3.org/1998/Math/MathML" display="inline"> <q:mi>H</q:mi> <q:mi>γ</q:mi> <q:mi>γ</q:mi> </q:math> anomalous couplings within the context of an effective field theory. In this approach, the production cross section is constrained to be <s:math xmlns:s="http://www.w3.org/1998/Math/MathML" display="inline"> <s:msub> <s:mi>σ</s:mi> <s:mrow> <s:mi>γ</s:mi> <s:mi>H</s:mi> </s:mrow> </s:msub> <s:mo><</s:mo> <s:mn>16.4</s:mn> <s:mtext> </s:mtext> <s:mtext> </s:mtext> <s:mi>fb</s:mi> </s:math> at 95% confidence level (CL). Simultaneous constraints on four anomalous couplings involving <u:math xmlns:u="http://www.w3.org/1998/Math/MathML" display="inline"> <u:mi>H</u:mi> <u:mi>Z</u:mi> <u:mi>γ</u:mi> </u:math> and <w:math xmlns:w="http://www.w3.org/1998/Math/MathML" display="inline"> <w:mi>H</w:mi> <w:mi>γ</w:mi> <w:mi>γ</w:mi> </w:math> are provided. Additionally, the production rate for <y:math xmlns:y="http://www.w3.org/1998/Math/MathML" display="inline"> <y:mi>H</y:mi> <y:mo stretchy="false">→</y:mo> <y:mn>4</y:mn> <y:mo>ℓ</y:mo> </y: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: <bb:math xmlns:bb="http://www.w3.org/1998/Math/MathML" display="inline"> <bb:msub> <bb:mi>κ</bb:mi> <bb:mi>u</bb:mi> </bb:msub> <bb:mo>=</bb:mo> <bb:mo stretchy="false">(</bb:mo> <bb:mn>0.0</bb:mn> <bb:mo>±</bb:mo> <bb:mn>1.5</bb:mn> <bb:mo stretchy="false">)</bb:mo> <bb:mo>×</bb:mo> <bb:msup> <bb:mn>10</bb:mn> <bb:mn>3</bb:mn> </bb:msup> </bb:math> , <fb:math xmlns:fb="http://www.w3.org/1998/Math/MathML" display="inline"> <fb:msub> <fb:mi>κ</fb:mi> <fb:mi>d</fb:mi> </fb:msub> <fb:mo>=</fb:mo> <fb:mo stretchy="false">(</fb:mo> <fb:msubsup> <fb:mn>0.0</fb:mn> <fb:mrow> <fb:mo>−</fb:mo> <fb:mn>6.8</fb:mn> </fb:mrow> <fb:mrow> <fb:mo>+</fb:mo> <fb:mn>6.7</fb:mn> </fb:mrow> </fb:msubsup> <fb:mo stretchy="false">)</fb:mo> <fb:mo>×</fb:mo> <fb:msup> <fb:mn>10</fb:mn> <fb:mn>2</fb:mn> </fb:msup> </fb:math> , <jb:math xmlns:jb="http://www.w3.org/1998/Math/MathML" display="inline"> <jb:msub> <jb:mi>κ</jb:mi> <jb:mi>s</jb:mi> </jb:msub> <jb:mo>=</jb:mo> <jb:msubsup> <jb:mn>0</jb:mn> <jb:mrow> <jb:mo>−</jb:mo> <jb:mn>32</jb:mn> </jb:mrow> <jb:mrow> <jb:mo>+</jb:mo> <jb:mn>30</jb:mn> </jb:mrow> </jb:msubsup> </jb:math> , and <lb:math xmlns:lb="http://www.w3.org/1998/Math/MathML" display="inline"> <lb:msub> <lb:mi>κ</lb:mi> <lb:mi>c</lb:mi> </lb:msub> <lb:mo>=</lb:mo> <lb:msubsup> <lb:mn>0.0</lb:mn> <lb:mrow> <lb:mo>−</lb:mo> <lb:mn>2.8</lb:mn> </lb:mrow> <lb:mrow> <lb:mo>+</lb:mo> <lb:mn>2.3</lb:mn> </lb:mrow> </lb:msubsup> </lb: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%.