Tuesday, 8 November 2022 at 11:15
The Standard Model has enjoyed many successes over its 50-year existence, but for theoretical and experimental reasons it is clearly not our final understanding of Nature. For example, experimental measurements of rare decays of B hadrons show a deviation from the flavor universality predicted by the SM. Leptoquarks (LQs) with preferential couplings to third-generation fermions offer a good explanation, and can be directly searched for in proton-proton collisions at detectors like ATLAS & CMS.
This presentations discusses the recently preliminary results for a combined search for a LQ with tau leptons and b quarks signatures at CMS. The analysis considers single and pair production of scalar or vector LQs, as well as the novel nonresonant production of a pair of tau leptons through the t-channel exchange of a LQ. Upper limits are set on the LQ production cross section and coupling strength in the LQ mass range 0.5-2.3 TeV. Intriguingly, a significance up to 3.4 standard deviations above the standard model expectation is observed in the data for the nonresonant signal, depending on the assumed coupling and LQ mass.