Testing Supersymmetry at the LHC through gluon-fusion production of a slepton pair

Abstract

Renormalizable quartic couplings among new particles are typical of supersymmetric models. Their detection could provide a test for Supersymmetry, discriminating it from other extensions of the Standard Model. Quartic couplings among squarks and sleptons, together with the SU(3) gauge couplings for squarks, allow the production of a pair of sleptons through gluon fusion, at the one-loop level. The corresponding cross section, however, is at most of $\mathcal{O}(1)$ fb for slepton and squark masses of $\mathcal{O}\left( {100} \right)$ GeV. Our investigation is then extended to the gluon-fusion production of sleptons through the exchange of Higgs bosons. The cross section is even smaller, of $\mathcal{O}\left( {0.1} \right)$ fb, if the exchanged Higgs boson has mass considerably below the slepton-pair threshold, but it is enhanced when it is resonant. It can reach the $\mathcal{O}\left( {10} \right)$ fb mark for the production of sleptons of same chirality, and it can exceed it for the production of $\tilde{\tau }$’s of opposite chirality, even when the chirality-mixing terms in the squark sector are vanishing. The cross section may be further enhanced if these mixing terms are nonnegligible, providing therefore a potentially interesting probe of the Higgs sector, in particular of μ, tan β, and the trilinear soft Supersymmetry-breaking couplings, also for more realistic sfermion spectra.