Complete resummation of chirally-enhanced loop-effects in the MSSM with non-minimal sources of flavor-violation

In this article we present the complete resummation of the leading chirally-enhanced corrections stemming from gluino-squark, chargino-sfermion and neutralino-sfermion loops in the MSSM with non-minimal sources of flavor-violation. We compute the finite renormalization of fermion masses and the CKM matrix induced by chirality-flipping self-energies. In the decoupling limit Msusy>>v, which is an excellent approximation to the full theory, we give analytic results for the effective gaugino(higgsino)-fermion-sfermion and the Higgs-fermion-fermion vertices. Using these vertices as effective Feynman rules, all leading chirally-enhanced corrections can consistently be included into perturbative calculations of Feynman amplitudes. We also give a generalized parametrization for the bare CKM matrix which extends the classic Wolfenstein parametrization to the case of complex parameters lambda and A.Comment: 31 pages, 3 figures; typos correcte

SUSY_FLAVOR v2.5: a computational tool for FCNC and CP-violating processes in the MSSM

We present SUSY_FLAVOR version 2.5 - a Fortran 77 program that calculates low-energy flavor observables in the general $R$-parity conserving MSSM. For a set of MSSM parameters as input, the code gives predictions for: 1. Electric dipole moments of the leptons and the neutron. 2. Anomalous magnetic moments (i.e. $g-2$) of the leptons. 3. Radiative lepton decays ($\mu\to e\gamma$ and $\tau\to \mu\gamma, e\gamma$). 4. Rare Kaon decays ($K^0_L\to \pi^0\bar\nu\nu$ and $K^+\to \pi^+ \bar\nu\nu$). 5. Leptonic $B$ decays ($B_{s,d}\to l^+ l^-$, $B\to \tau \nu$, $B\to D \tau \nu$ and $B\to D^\star \tau \nu$). 6. Radiative $B$ decays ($B\to\bar X_s \gamma$). 7. Rare decays of top quark to Higgs boson ($t\to ch,uh$). 8. $\Delta F=2$ processes ($\bar K^0-K^0$, $\bar D-D$, $\bar B_d-B_d$ and $\bar B_s-B_s$ mixing). SUSY_FLAVOR performs the resummation of all chirally enhanced corrections, i.e. takes into account the effects enhanced by $\tan\beta$ and/or large trilinear soft mixing terms to all orders in perturbation theory. All calculations are done using exact diagonalization of the sfermion mass matrices. Comparing to previous versions, in SUSY_FLAVOR v2.5 parameter initialization in SLHA2 format has been significantly generalized and simplified, so that program accepts without modifications most of the output files produced by other codes calculating MSSM spectra and processes. In addition, the routine calculating branching ratios for rare decays of top quark to Higgs boson has been included. The program can be obtained from www.fuw.edu.pl/susy_flavor.Comment: Updated from arXiv:1003.4260 [hep-ph] (SUSY_FLAVOR v1 manual), 61 pages; updated sections on modified user interface and on newly added processes. SUSY_FLAVOR code available at http://www.fuw.edu.pl/susy_flavo

Natural SUSY and Kaon Mixing in view of recent results from Lattice QCD

Lattice results are available for Delta S=2 matrix elements for the first time in full QCD, which improve considerably the status of hadronic uncertainties in K-Kbar mixing with respect to earlier phenomenological studies. Using an average of the ETMC and RBC results, we analyze epsilonK in Natural SUSY. This scenario arises as a consistent BSM framework after the latest results from the LHC. The analysis is improved with respect to previous studies including next-to-leading order matching conditions of order (alpha_s)^3. We derive new bounds for SUSY mass insertions in the scenario with a light third generation and study the implications for squark and gluino masses, compared with direct searches at the LHC. Assuming natural values for the flavor violating SUSY couplings of both chiralities, we find that the sbottom must be heavier than 3 TeV for a gluino mass up to 10 TeV. In this scenario no natural values for squark and gluino masses can satisfy the flavor bounds.Comment: v3: Results updated with the latest (September 2012) lattice QCD results. Version published in Physical Review

Top mass dependent alpha_s^3 corrections to B-meson mixing in the MSSM

We compute the top mass dependent NLO strong interaction matching conditions to the Delta F=2 effective Hamiltonian in the general MSSM. We study the relevance of such corrections, comparing its size with that of previously known NLO corrections in the limit mt->0, in scenarios with degeneracy, alignment, and hierarchical squarks. We find that, while these corrections are generally small, there are regions in the parameter space where the contributions to the Wilson coefficients C1 and C4 could partially overcome the expected suppression m_t/M_SUSY.Comment: 15 pages, 6 figure

Supersymmetric contributions to Bˉs→ϕπ0\bar{B}_s \to \phi \pi^0 and Bˉs→ϕρ0\bar{B}_s \to \phi \rho^0 decays in SCET

We study the decay modes $\bar{B}_s\to \phi \pi^0$ and $\bar{B}_s\to \phi \rho^0$ 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 $\bar{B}_s\to \phi \pi^0 =7_{-1-2}^{+1+2}\times 10^{-8}$ and BR $\bar{B}_s\to \phi \pi^0=9_{-1-4}^{+1+3}\times 10^{-8}$ corresponding to solution 1 and solution 2 of the SCET parameters respectively.For the decay mode $\bar{B}_s\to \phi \rho^0$, we find that BR $\bar{B}_s\to \phi \rho^0 = 20.2^{+1+9}_{-1-12}\times 10^{-8}$ and BR $\bar{B}_s\to \phi \rho^0 = 34.0^{+1.5 + 15}_{-1.5-22}\times 10^{-8}$ 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 $\bar{B}_s\to \phi \pi^0$ and $\bar{B}_s\to \phi \rho^0$. In addition, we show that SUSY contributions mediated by chargino exchange can enhance the branching ratio of $\bar{B}_s\to \phi \pi^0$ by about 14% with respect to the SM prediction. For the branching ratio of $\bar{B}_s\to \phi \rho^0$, we find that SUSY contributions can enhance its value by about 1% with respect to the SM prediction.Comment: 25 pages,5 figures, version accepted for publicatio

Hints of R-parity violation in B decays into τν\tau \nu

In this article we show that the recently observed enhanced semi-leptonic and leptonic decay rates of the B meson into \tau \nu modes can be explained within the frame work of R-parity violating (RPV) MSSM. In particular, RPV contributions involving the exchange of right-handed down-type squarks give a universal contribution to the B+ --> \tau \nu, B --> D \tau \nu and the B --> D* \tau \nu decays. We find that the masses and couplings that explain the enhanced B decay rates are phenomelogically viable and the squarks can possibly be observed at the LHC.Comment: 8 pages and 3 figures; Updated section 2 and 3, but results are unmodifie

Lepton flavour violation in the MSSM

We derive new constraints on the quantities delta_{XY}^{ij}, X,Y=L,R, which parametrise the flavour-off-diagonal terms of the charged slepton mass matrix in the MSSM. Considering mass and anomalous magnetic moment of the electron we obtain the bound |delta^{13}_{LL} delta^{13}_{RR}|<0.1 for tan beta=50, which involves the poorly constrained element delta^{13}_{RR}. We improve the predictions for the decays tau -> mu gamma, tau -> e gamma and mu -> e gamma by including two-loop corrections which are enhanced if tan beta is large. The finite renormalisation of the PMNS matrix from soft SUSY-breaking terms is derived and applied to the charged-Higgs-lepton vertex. We find that the experimental bound on BR(tau -> e gamma) severely limits the size of the MSSM loop correction to the PMNS element U_{e3}, which is important for the proper interpretation of a future U_{e3} measurement. Subsequently we confront our new values for delta^{ij}_{LL} with a GUT analysis. Further, we include the effects of dimension-5 Yukawa terms, which are needed to fix the Yukawa unification of the first two generations. If universal supersymmetry breaking occurs above the GUT scale, we find the flavour structure of the dimension-5 Yukawa couplings tightly constrained by mu -> e gamma.Comment: 37 pages, 15 figures; typo in Equation (35) and (49) correcte