Pair production of neutralinos and charginos at the LHC: the role of Higgs bosons exchange

We analyze the effects of the s-channel Higgs bosons exchange on the charginos and neutralinos-pair production in proton-proton collision at the CERN Large Hadron Collider (LHC) in the following channels: $pp \to \Cha^+\Cha^-/\Neu^0\Neu^0 + X$, within the minimal supersymmetric standard model (MSSM). Assuming the usual GUT relation between $M_1$ and $M_2$ at the weak scale, we found that substantial enhancement can be obtained through s-channel Higgs bosons exchange in the mixed regime where $M_2 \sim |\mu|$ with moderate to large $\tan\beta$ at the resonance of the heavy Higgs bosons. By Combining the phenomenological constraints on neutralinos and charginos, we may still find regions of parameter space where charginos and neutralinos-pair production at the LHC from $b\bar b$ initial state can be large and observable at LHC. We also compute the full complete set of electroweak (EW) contributions to $pp\to gg\to \Cha^+\Cha^-/\Neu^0\Neu^0 + X$ at one loop level in the general MSSM. The analytical computation of the complete tree level amplitude for $b\bar{b} \to \Cha^+\Cha^-/\Neu^0\Neu^0 + X$, including s-channel Higgs exchange, is given.