Higgs boson decay to charm pair at full one-loop level in the MSSM with flavour violation

We study the decay of the lightest neutral Higgs boson to a charm quark pair at full one-loop level in the MSSM with non-minimal quark flavour violation (QFV). In the numerical analysis we consider mixing between the second and the third squark generation and all relevant constraints from B meson data are taken into account. It is shown that the full one-loop corrected decay width can be quite sensitive to the MSSM QFV parameters due to large $tilde c - tilde t$ mixing and large trilinear couplings. After summarising the theoretical and experimental errors, we conclude that an observation of these SUSY QFV effects is possible at the ILC.

$h^0 to c bar{c}$ as a test case for quark flavor violation in the MSSM

We compute the decay width of $h^0 to c bar{c}$ in the MSSM with quark flavor violation (QFV) at full one-loop level adopting the $overline{rm DR}$ renormalisation scheme. We study the effects of $tilde{c}-tilde{t}$ mixing, taking into account the constraints from the B meson data. We show that the full one-loop corrected decay width $Gamma (h^0 to c bar{c})$ is very sensitive to the MSSM QFV parameters. In a scenario with large $tilde{c}_{L,R}-tilde{t}_{L,R}$ mixing $Gamma (h^0 to c bar{c})$ can differ up to $sim pm 35%$ from its SM value. After estimating the uncertainties of the width, we conclude that an observation of these SUSY QFV effects is possible at an $e^+ e^-$ collider (ILC).

CP violation in $H^pm t$ production at the LHC

We study effects of CP violation in the associated production of a charged Higgs boson and a top quark at the LHC, $pp to tH^pm + X$. We calculate the CP violating asymmetry between the total cross section for $H^+$ and $H^-$ production at next-to-leading order in the MSSM, and perform a detailed numerical analysis. In the production the asymmetry is of the order of 20%. The asymmetry in the production and any subsequent decay of an on-shell charged Higgs boson is to a good approximation the sum of the asymmetry in the production and the asymmetry in the decay. We consider subsequent decays of $H^pm $ to $t b$, $ u_tau tau^pm$ and $W h^0$. In the case with $H^pm to t b$ decay, mainly due to CP violating box graphs with gluino, the asymmetry can go up to $sim$ 12%.