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Register a new userQuark-flavour violation in $h^0 to b bar{b}$ in the MSSM at one-loop level
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We compute the width of the decay $h^0$ (125 GeV) $to b bar{b}$ at next-to-leading order in the general MSSM with quark-flavour violation (QFV). We study the effect of mixing between the second and the third generation of squarks, taking into account the constraints on QFV from B-meson data. We discuss the renormalisation of the process as well as the resummation of the bottom Yukawa coupling at large $tan beta$. We show numerical results on the decay width $Gamma(h^0 to b bar{b})$ as a function of the involved QFV parameters and compare them with the corresponding width in the Standard Model.
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We calculate the decay width of h0 -> b bbar in the Minimal Supersymmetric Standard Model (MSSM) with quark flavour violation (QFV) at full one-loop level. We study the effect of scharm-stop mixing and sstrange-sbottom mixing taking into account the constraints from the B meson data. We discuss and compare in detail the decays h0 -> c cbar and h0 -> b bbar within the framework of the perturbative mass insertion technique using the Flavour Expansion Theorem. The deviation of both decay widths from the Standard Model values can be quite large. Whereas in h0 -> c cbar it is almost entirely due to the flavour violating part of the MSSM, in h0 -> b bbar it is mainly due to the flavour conserving part. Nevertheless, the QFV contribution to Gamma(h0 -> b bbar) due to scharm-stop mixing and chargino exchange can go up to about 8%.
We study the two-body decays of the gluino at full one-loop level in the Minimal Supersymmetric Standard Model with quark-flavour violation (QFV) in the squark sector. The renormalization is done in the DRbar scheme and hard gluon and photon radiations are included by adding the corresponding three-body decay widths. In the numerics the dependence of the gluino decay widths on the QFV parameters is discussed with special emphasis put on the separation of the electroweak and the SUSY QCD corrections. The main dependence stems from the $tilde c_R - tilde t_R$ mixing in the decays to up-type squarks because there hold strong constraints from B-physics on the other quark-flavour mixing parameters. Including the full one-loop corrections, the changes of the gluino decay widths are mostly negative and of the order of about -10%. The QFV part stays small in the total width but can vary up to -8% for the decay width into the lightest squark. For the corresponding branching ratio, however, the effect is smaller by at least a factor of two. The electroweak corrections can become 35% of the SUSY QCD corrections.
We consider the K^0 - bar K^0 and B^0 - bar B^0 mixings in the MSSM with the two-Higgs-doublet scalar sector featuring explicit CP violation, and the Yukawa sector of type II. In the case of strong mixing between CP-odd and CP-even states the existence of light charged Higgs is allowed in the model. The mass splitting Delta m_{LS} and the amount of indirect CP violation epsilon are calculated. In the limit of effective low-energy approximation the nonstandard effects are shown to be negligibly small in Delta m_{LS} and epsilon for the K^0-mesons, being almost independent on the charged Higgs boson mass. However, for the B_d^0 - bar B_d^0 and B_s^0 - bar B_s^0 systems the effects of nonstandard physics are shown to be larger, limiting the MSSM parameter space.
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.
We study the loop-induced decays $h^0 to gamma , gamma$ and $h^0 to g , g$ in the Minimal Supersymmetric Standard Model (MSSM) with quark flavour violation (QFV), identifying $h^0$ with the Higgs boson with a mass of 125 GeV, where $gamma$ and $g$ are photon and gluon, respectively. We perform a MSSM parameter scan and a detailed analysis around a fixed reference point respecting theoretical constraints from vacuum stability conditions and experimental constraints, such as those from B meson data and electroweak precision data, as well as recent limits on supersymmetric (SUSY) particle masses from LHC experiments. We find that (i) the relative deviation of the decay width $Gamma(h^0 to g , g)$ from the Standard Model value, $DEV(g)$, can be large and negative, $lesssim - 15%$, (ii) the analogous deviation of $Gamma(h^0 to gamma , gamma)$ is strongly correlated, $DEV(gamma) simeq -1/4,DEV(g)$ for $DEV(g) lesssim - 4%$, (iii) the relative deviation of the width ratio $Gamma(h^0 to gamma , gamma)/Gamma(h^0 to g , g)$ from the SM value, $DEV(gamma/g)$, can be large (up to $sim$ 20%), (iv) the deviations can be large due to the up-type squark loop contributions, (v) the SUSY QFV parameters can have a significant effect on these deviations. Such large deviations can be observed at a future $e^+e^-$ collider like ILC. Observation of the deviation patterns as shown in this study would favour the MSSM with flavour-violating squark mixings and encourage to perform further studies in this model.
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