Article

Constraining the MSSM sfermion mass matrices with light fermion masses

Physical review D: Particles and fields 02/2010; DOI: 10.1103/PhysRevD.81.076001
Source: arXiv

ABSTRACT We study the finite supersymmetric loop corrections to fermion masses and mixing matrices in the generic MSSM. In this context the effects of non-decoupling chirally-enhanced self-energies are studied beyond leading order in perturbation theory. These NLO corrections are not only necessary for the renormalization of the CKM matrix to be unitary, they are also numerically important for the light fermion masses. Focusing on the tri-linear A-terms with generic flavor-structure we derive very strong bounds on the chirality-changing mass insertions delta^{f\,LR,RL}_{IJ} by applying 't Hooft's naturalness criterion. In particular, the NLO corrections to the up quark mass allow us to constrain the unbounded element delta^{u\,RL}_{13} if at the same time $\delta^{u\,LR}_{13}$ is unequal to zero. Our result is important for single-top production at the LHC. Comment: 12 pages, 10 figures

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ABSTRACT: We study the decay modes {overline B_s} to φ {π^0} and {overline B_s} to φ {ρ^0} using Soft Collinear Effective Theory. Within Standard Model and including the error due to the SU(3) breaking effect in the SCET parameters we find that BR {overline B_s} to φ {π^0} = 7_{ - 1 - 2}^{ + 1 + 2} × {10^{ - 8}} and BR {overline B_s} to φ {π^0} = 9_{ - 1 - 4}^{ + 1 + 3} × {10^{ - 8}} corresponding to solution 1 and solution 2 of the SCET parameters respectively. For the decay mode {overline B_s} to φ {ρ^0}, we find that BR {overline B_s} to φ {ρ^0} = 20.2_{ - 1 - 12}^{ + 1 + 9} × {10^{ - 8}} and BR {overline B_s} to φ {ρ^0} = 34.0_{ - 1.5 - 22}^{ + 1.5 + 15} × {10^{ - 8}} corresponding to solution 1 and solution 2 of the SCET parameters respectively. We extend our study to include supersymmetric models with non-universal A-terms where the dominant contributions arise from diagrams mediated by gluino and chargino exchanges. We show that gluino contributions can not lead to an enhancement of the branching ratios of {overline B_s} to φ {π^0} and {overline B_s} to φ {ρ^0}. In addition, we show that SUSY contributions mediated by chargino exchange can enhance the branching ratio of {overline B_s} to φ {π^0} by about 14 % with respect to the SM prediction. For the branching ratio of {overline B_s} to φ {ρ^0}, we find that SUSY contributions can enhance its value by about 1 % with respect to the SM prediction.
Journal of High Energy Physics 08/2012; · 6.22 Impact Factor
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ABSTRACT: We study the decay modes ${\overline B_s} \to \phi {\pi^0}$ and ${\overline B_s} \to \phi {\rho^0}$ using Soft Collinear Effective Theory. Within Standard Model and including the error due to the SU(3) breaking effect in the SCET parameters we find that BR ${\overline B_s} \to \phi {\pi^0} = 7_{ - 1 - 2}^{ + 1 + 2} \times {10^{ - 8}}$ and BR ${\overline B_s} \to \phi {\pi^0} = 9_{ - 1 - 4}^{ + 1 + 3} \times {10^{ - 8}}$ corresponding to solution 1 and solution 2 of the SCET parameters respectively. For the decay mode ${\overline B_s} \to \phi {\rho^0}$ , we find that BR ${\overline B_s} \to \phi {\rho^0} = 20.2_{ - 1 - 12}^{ + 1 + 9} \times {10^{ - 8}}$ and BR ${\overline B_s} \to \phi {\rho^0} = 34.0_{ - 1.5 - 22}^{ + 1.5 + 15} \times {10^{ - 8}}$ corresponding to solution 1 and solution 2 of the SCET parameters respectively. We extend our study to include supersymmetric models with non-universal A-terms where the dominant contributions arise from diagrams mediated by gluino and chargino exchanges. We show that gluino contributions can not lead to an enhancement of the branching ratios of ${\overline B_s} \to \phi {\pi^0}$ and ${\overline B_s} \to \phi {\rho^0}$ . In addition, we show that SUSY contributions mediated by chargino exchange can enhance the branching ratio of ${\overline B_s} \to \phi {\pi^0}$ by about 14 % with respect to the SM prediction. For the branching ratio of ${\overline B_s} \to \phi {\rho^0}$ , we find that SUSY contributions can enhance its value by about 1 % with respect to the SM prediction.
Journal of High Energy Physics 2012(8). · 6.22 Impact Factor
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Article: 1-loop SQCD corrections to the decay of top-squarks to charm and neutralino in the generic MSSM
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