Measurement of WWZ and ZH Production Cross Sections at s=13 and 13.6 TeV

Abstract

A measurement is presented of the cross section in proton-proton collisions for the production of two <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>W</a:mi></a:math> bosons and one <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mi>Z</c:mi></c:math> boson. It is based on data recorded by the CMS experiment at the CERN LHC at center-of-mass energies <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:msqrt><e:mi>s</e:mi></e:msqrt><e:mo>=</e:mo><e:mn>13</e:mn></e:math> and 13.6 TeV, corresponding to an integrated luminosity of <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"><g:mn>200</g:mn><g:mtext> </g:mtext><g:mtext> </g:mtext><g:msup><g:mi>fb</g:mi><g:mrow><g:mo>−</g:mo><g:mn>1</g:mn></g:mrow></g:msup></g:math>. Events with four charged leptons (electrons or muons) in the final state are selected. Both nonresonant <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"><i:mi>W</i:mi><i:mi>W</i:mi><i:mi>Z</i:mi></i:math> production and <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"><k:mi>Z</k:mi><k:mi>H</k:mi></k:math> production, with the Higgs boson decaying into two <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"><m:mi>W</m:mi></m:math> bosons, are reported. For the first time, the two processes are measured separately in a simultaneous fit. Combining the two modes, signal strengths relative to the standard model (SM) predictions of <o:math xmlns:o="http://www.w3.org/1998/Math/MathML" display="inline"><o:msubsup><o:mn>0.75</o:mn><o:mrow><o:mo>−</o:mo><o:mn>0.29</o:mn></o:mrow><o:mrow><o:mo>+</o:mo><o:mn>0.34</o:mn></o:mrow></o:msubsup></o:math> and <q:math xmlns:q="http://www.w3.org/1998/Math/MathML" display="inline"><q:msubsup><q:mn>1.74</q:mn><q:mrow><q:mo>−</q:mo><q:mn>0.60</q:mn></q:mrow><q:mrow><q:mo>+</q:mo><q:mn>0.71</q:mn></q:mrow></q:msubsup></q:math> are measured for <s:math xmlns:s="http://www.w3.org/1998/Math/MathML" display="inline"><s:msqrt><s:mi>s</s:mi></s:msqrt><s:mo>=</s:mo><s:mn>13</s:mn></s:math> and 13.6 TeV, respectively. The observed (expected) significance for the triboson signal is 3.8 (2.5) standard deviations for <u:math xmlns:u="http://www.w3.org/1998/Math/MathML" display="inline"><u:mrow><u:msqrt><u:mrow><u:mi>s</u:mi></u:mrow></u:msqrt><u:mo>=</u:mo><u:mn>13.6</u:mn><u:mtext> </u:mtext><u:mtext> </u:mtext><u:mi>TeV</u:mi></u:mrow></u:math>, thus providing the first evidence for triboson production at this center-of-mass energy. Combining the two modes and the two center-of-mass energies, the inclusive signal strength relative to the SM prediction is measured to be <w:math xmlns:w="http://www.w3.org/1998/Math/MathML" display="inline"><w:msubsup><w:mn>1.03</w:mn><w:mrow><w:mo>−</w:mo><w:mn>0.28</w:mn></w:mrow><w:mrow><w:mo>+</w:mo><w:mn>0.31</w:mn></w:mrow></w:msubsup></w:math>, with an observed (expected) significance of 4.5 (5.0) standard deviations.