No Arabic abstract
We show compatibility with all known experimental constraints of t-b-tau Yukawa coupling unification in supersymmetric SU(4)_c x SU(2)_L x SU(2)_R which has non-universal gaugino masses and the MSSM parameter mu < 0. In particular, the relic neutralino abundance satisfies the WMAP bounds and Delta (g-2)_mu is in good agreement with the observations. We identify benchmark points for the sparticle spectra which can be tested at the LHC, including those associated with gluino and stau coannihilation channels, mixed bino-Higgsino state and the A-funnel region. We also briefly discuss prospects for testing Yukawa unification with the ongoing and planned direct detection experiments.
We consider two classes of t-b-tau quasi-Yukawa unification scenarios which can arise from realistic supersymmetric SO(10) and SU(4)_C X SU(2)_L X SU(2)_R models. We show that these scenarios can be successfully implemented in the CMSSM and NUHM1 frameworks, and yields a variety of sparticle spectra with WMAP compatible neutralino dark matter. In NUHM1 we find bino-higgsino dark matter as well as the stau coannihilation and A-funnel solutions. The CMSSM case yields the stau coannihilation and A-funnel solutions. The gluino and squark masses are found to lie in the TeV range.
We explore the implications of t-b-tau (and b-tau) Yukawa coupling unification condition on the fundamental parameter space and sparticle spectroscopy in the minimal gauge mediated supersymmetry breaking (mGMSB) model. We find that this scenario prefers values of the CP-odd Higgs mass m_A > 1 TeV, with all colored sparticle masses above 3 TeV. These predictions will be hard to test at LHC13 but they may be testable at HE-LHC 33 TeV or a 100 TeV collider. Both t-b-tau and b-tau Yukawa coupling unifications prefer a relatively light gravitino with mass < 30 eV, which makes it a candidate hot dark matter particle. However, it cannot account for more than 15 % of the observed dark matter density.
We investigate the possibility of indirectly constraining the $B^{+}to K^{+}tau^+tau^-$ decay rate using precise data on the $B^{+}to K^{+}mu^+mu^-$ dimuon spectrum. To this end, we estimate the distortion of the spectrum induced by the $B^{+}to K^{+}tau^+tau^-to K^{+} mu^+mu^-$ re-scattering process, and propose a method to simultaneously constrain this (non-standard) contribution and the long-distance effects associated to hadronic intermediate states. The latter are constrained using the analytic properties of the amplitude combined with data and perturbative calculations. Finally, we estimate the sensitivity expected at the LHCb experiment with present and future datasets. We find that constraints on the branching fraction of $O(10^{-3})$, competitive with current direct bounds, can be achieved with the current dataset, while bounds of $O(10^{-4})$ could be obtained with the LHCb upgrade-II luminosity.
One of the main indications for New Physics in rare $B$-decays is deduced from the tension between experimental and Standard Model predictions of the angular analysis of the $B^0 to K^{*0} mu^+mu^-$ decay. There are however possible non-local hadronic effects which in principle can also explain these tensions. In this work, we consider a statistical approach for differentiating the source of the tension in $B^0 to K^{*0} mu^+mu^-$ observables and we also investigate the prospects of such a comparison with future data from the LHCb experiment.
The branching fraction ratio $mathcal{R}(D^{*}) equiv mathcal{B}(overline{B}^0 to D^{*+}tau^{-}overline{ u}_{tau})/mathcal{B}(overline{B}^0 to D^{*+}mu^{-}overline{ u}_{mu})$ is measured using a sample of proton-proton collision data corresponding to 3.0invfb of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode $tau^{-} to mu^{-}overline{ u}_{mu} u_{tau}$. The semitauonic decay is sensitive to contributions from non-Standard-Model particles that preferentially couple to the third generation of fermions, in particular Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate $overline{B}^0$ decays gives $mathcal{R}(D^{*}) = 0.336 pm 0.027(stat) pm 0.030 (syst)$. This result, which is the first measurement of this quantity at a hadron collider, is $2.1$ standard deviations larger than the value expected from lepton universality in the Standard Model.