Search for charged Higgs bosons produced in top-quark decays or in association with top quarks and decaying via H±→τ±ντ in 13 TeV p</…

Charged Higgs bosons produced either in top-quark decays or in association with a top quark, subsequently decaying via <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi>H</a:mi><a:mo>±</a:mo></a:msup><a:mo stretchy="false">→</a:mo><a:msup><a:mi>τ</a:mi><a:mo>±</a:mo></a:msup><a:msub><a:mi>ν</a:mi><a:mi>τ</a:mi></a:msub></a:math>, are searched for in <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline"><d:mn>140</d:mn><d:mtext> </d:mtext><d:mtext> </d:mtext><d:msup><d:mi>fb</d:mi><d:mrow><d:mo>−</d:mo><d:mn>1</d:mn></d:mrow></d:msup></d:math> of proton-proton collision data at <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" display="inline"><f:msqrt><f:mi>s</f:mi></f:msqrt><f:mo>=</f:mo><f:mn>13</f:mn><f:mtext> </f:mtext><f:mtext> </f:mtext><f:mi>TeV</f:mi></f:math> recorded with the ATLAS detector. Depending on whether the top quark is produced together with the <h:math xmlns:h="http://www.w3.org/1998/Math/MathML" display="inline"><h:msup><h:mi>H</h:mi><h:mo>±</h:mo></h:msup></h:math> decays hadronically or semileptonically, the search targets <j:math xmlns:j="http://www.w3.org/1998/Math/MathML" display="inline"><j:mi>τ</j:mi><j:mo>+</j:mo><j:mtext>jets</j:mtext></j:math> or <l:math xmlns:l="http://www.w3.org/1998/Math/MathML" display="inline"><l:mi>τ</l:mi><l:mo>+</l:mo><l:mi>lepton</l:mi></l:math> final states, in both cases with a <n:math xmlns:n="http://www.w3.org/1998/Math/MathML" display="inline"><n:mi>τ</n:mi></n:math>-lepton decaying into a neutrino and hadrons. No significant excess over the Standard Model background expectation is observed. For the mass range of <p:math xmlns:p="http://www.w3.org/1998/Math/MathML" display="inline"><p:mn>80</p:mn><p:mo>≤</p:mo><p:msub><p:mi>m</p:mi><p:msup><p:mi>H</p:mi><p:mo>±</p:mo></p:msup></p:msub><p:mo>≤</p:mo><p:mn>3000</p:mn><p:mtext> </p:mtext><p:mtext> </p:mtext><p:mi>GeV</p:mi></p:math>, upper limits at 95% confidence level are set on the production cross section of the charged Higgs boson times the branching fraction <r:math xmlns:r="http://www.w3.org/1998/Math/MathML" display="inline"><r:mi mathvariant="script">B</r:mi><r:mo stretchy="false">(</r:mo><r:msup><r:mi>H</r:mi><r:mo>±</r:mo></r:msup><r:mo stretchy="false">→</r:mo><r:msup><r:mi>τ</r:mi><r:mo>±</r:mo></r:msup><r:msub><r:mi>ν</r:mi><r:mi>τ</r:mi></r:msub><r:mo stretchy="false">)</r:mo></r:math> in the range 4.5 pb–0.4 fb. In the mass range 80–160 GeV, assuming the Standard Model cross section for <x:math xmlns:x="http://www.w3.org/1998/Math/MathML" display="inline"><x:mi>t</x:mi><x:mover accent="true"><x:mi>t</x:mi><x:mo stretchy="false">¯</x:mo></x:mover></x:math> production, this corresponds to upper limits between 0.27% and 0.02% on <bb:math xmlns:bb="http://www.w3.org/1998/Math/MathML" display="inline"><bb:mi mathvariant="script">B</bb:mi><bb:mo stretchy="false">(</bb:mo><bb:mi>t</bb:mi><bb:mo stretchy="false">→</bb:mo><bb:mi>b</bb:mi><bb:msup><bb:mi>H</bb:mi><bb:mo>±</bb:mo></bb:msup><bb:mo stretchy="false">)</bb:mo><bb:mo>×</bb:mo><bb:mi mathvariant="script">B</bb:mi><bb:mo stretchy="false">(</bb:mo><bb:msup><bb:mi>H</bb:mi><bb:mo>±</bb:mo></bb:msup><bb:mo stretchy="false">→</bb:mo><bb:msup><bb:mi>τ</bb:mi><bb:mo>±</bb:mo></bb:msup><bb:msub><bb:mi>ν</bb:mi><bb:mi>τ</bb:mi></bb:msub><bb:mo stretchy="false">)</bb:mo></bb:math>.