Abstract:
A search is performed for dark matter particles produced in association with a resonantly produced pair of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>b</a:mi></a:math>-quarks with <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mrow><c:mn>30</c:mn><c:mo><</c:mo><c:msub><c:mrow><c:mi>m</c:mi></c:mrow><c:mrow><c:mi>b</c:mi><c:mi>b</c:mi></c:mrow></c:msub><c:mo><</c:mo><c:mn>150</c:mn><c:mtext> </c:mtext><c:mtext> </c:mtext><c:mi>GeV</c:mi></c:mrow></c:math> using <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mrow><e:mn>140</e:mn><e:mtext> </e:mtext><e:mtext> </e:mtext><e:msup><e:mrow><e:mi>fb</e:mi></e:mrow><e:mrow><e:mo>−</e:mo><e:mn>1</e:mn></e:mrow></e:msup></e:mrow></e:math> of proton-proton collisions at a center-of-mass energy of 13 TeV recorded by the ATLAS detector at the LHC. This signature is expected in extensions of the standard model predicting the production of dark matter particles, in particular those containing a dark Higgs boson <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"><g:mi>s</g:mi></g:math> that decays into <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"><i:mi>b</i:mi><i:mover accent="true"><i:mi>b</i:mi><i:mo stretchy="false">¯</i:mo></i:mover></i:math>. The highly boosted <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"><m:mi>s</m:mi><m:mo stretchy="false">→</m:mo><m:mi>b</m:mi><m:mover accent="true"><m:mi>b</m:mi><m:mo stretchy="false">¯</m:mo></m:mover></m:math> topology is reconstructed using jet reclustering and a new identification algorithm. This search places stringent constraints across regions of the dark Higgs model parameter space that satisfy the observed relic density, excluding dark Higgs bosons with masses between 30 and 150 GeV in benchmark scenarios with <r:math xmlns:r="http://www.w3.org/1998/Math/MathML" display="inline"><r:msup><r:mi>Z</r:mi><r:mo>′</r:mo></r:msup></r:math> mediator masses up to 4.8 TeV at 95% confidence level. © 2025 CERN, for the ATLAS Collaboration 2025 CERN
Tópico:
Particle physics theoretical and experimental studies
