<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>W</mml:mi></mml:math>-boson exotic decay into three charged leptons at the LHC

We investigate the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>W</a:mi></a:math> boson’s exotic decay channel, <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mi>W</c:mi><c:mo stretchy="false">→</c:mo><c:mo>ℓ</c:mo><c:mo>ℓ</c:mo><c:mo>ℓ</c:mo><c:mi>ν</c:mi></c:math>, at the LHC. Although the four-body final states suppress the decay branching ratio, the large production of <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" display="inline"><f:mi>W</f:mi></f:math> bosons makes detecting and precisely measuring this decay probability entirely feasible. Our simulation study indicates that this tiny branching ratio can be measured with subpercent precision at the HL-LHC. This decay channel can also constrain Standard Model extensions. Using the <h:math xmlns:h="http://www.w3.org/1998/Math/MathML" display="inline"><h:msub><h:mi>L</h:mi><h:mi>μ</h:mi></h:msub><h:mo>−</h:mo><h:msub><h:mi>L</h:mi><h:mi>τ</h:mi></h:msub></h:math> model as a benchmark, we find that the current bound on the gauge coupling for <j:math xmlns:j="http://www.w3.org/1998/Math/MathML" display="inline"><j:msup><j:mi>Z</j:mi><j:mo>′</j:mo></j:msup></j:math> mass in the range of [4, 75] GeV can significantly improve. Published by the American Physical Society 2024