Resonant third-generation leptoquark signatures at the Large Hadron Collider
Ulrich Haisch, G. Polesello
Abstract
A bstract Given the hints of lepton-flavour non-universality in B -meson decays, leptoquarks (LQs) are enjoying a renaissance. We propose novel Large Hadron Collider (LHC) searches for such hypothetical states that do not rely on strong production only, but can also receive important contributions from quark-lepton annihilation. For the cases of a resonant signal involving a bottom quark and a tau lepton ( b + τ ), a top quark and missing transverse energy ( $$ {E}_T^{\mathrm{miss}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>E</mml:mi> <mml:mi>T</mml:mi> <mml:mtext>miss</mml:mtext> </mml:msubsup> </mml:math> ) and light-flavour jets plus $$ {E}_T^{\mathrm{miss}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>E</mml:mi> <mml:mi>T</mml:mi> <mml:mtext>miss</mml:mtext> </mml:msubsup> </mml:math> , we develop realistic analysis strategies and provide detailed evaluations of the achievable sensitivities for the corresponding LQ signatures at future LHC runs. Our analyses allow us to derive a series of stringent constraints on the masses and couplings of third-generation singlet vector LQs, showing that at LHC Run III and the high-luminosity LHC the proposed search channels can probe interesting parts of the LQ parameter space addressing the B -physics anomalies. In view of the reach of the proposed b + τ signature, we recommend that dedicated resonance searches for this final state should be added to the exotics search canon of both ATLAS and CMS.