5. Theoretical Physics (CSN4)

Single top and Higgs associated production as a probe of the Httbar coupling sign at the LHC

by Dr Sanjoy Biswas

Aula Seminari (LNF)

Aula Seminari


Via Enrico Fermi, 40 00044 Frascati (Roma)
The present Higgs data indicates that the Yukawa couplings can be somewhat different from those assumed in the Standard Model (SM) with a ambiguity in the sign. To lift this degeneracy one needs to look for production channels which are strongly sensitive to this sign. The single top production in association with a Higgs boson mainly involves the coupling of the Higgs with the top quark and the W boson, and can provide the necessary information. This process is highly sensitive to the relative sign between these two couplings. In fact, in the SM there is an almost perfect destructive interference between the two amplitudes, one containing the tH vertex and the other containing the WH one. We analyze the cross sections and the main irreducible backgrounds for the H->gamma gamma decay channel in the context of the LHC. Sensitivities to an anomalous sign for the top Yukawa coupling are found to be large.