Related papers: BR(Bs to mu+ mu-) as an electroweak precision test
In this talk, I review the status and prospects of several low energy flavor observables that are highly sensitive to New Physics effects. In particular I discuss the implications for possible New Physics in b --> s transitions coming from…
We present a search for the lepton flavor violating decay B+ --> K+ tau-/+ mu+/- using 383 million B Bbar events collected by the BABAR experiment. The branching fraction for this decay can be substantially enhanced in new physics models.…
We consider a new massive vector-boson Z' that couples to leptons through the L_mu - L_tau current, and to quarks through an arbitrary set of couplings. We show that such a model can be obtained from a renormalizable field theory involving…
We study constraints on new physics from the recent measurement of Br ($K^+ \to \pi^+ \nu \bar \nu)$ by the E787 and E949 Collaborations. In our analysis we consider two models of new physics: $(a)$ extra down type singlet quark model…
We speculate about the possible interpretations of the recently observed excess in the $h \to \tau \mu$ decay. We derive a robust lower bound on the Higgs boson coupling strength to a tau and a muon, even in presence of the most general new…
Due to the inclination for forward gauge radiation, lepton colliders beyond a few TeV are effectively electroweak (EW) boson colliders, suggesting the treatment of EW bosons as constituents of high-energy leptons. In the context of a muon…
In these proceedings we review the impact of additional Higgs bosons on $B$ physics observables. For this purpose, we consider first the 2HDM of type II which respects natural flavour conservation. Afterwards, we study a 2HDM with generic…
Motivated by the first evidence of the B -> tau nu transition reported by Belle and by the precise DeltaM_{B_s} measurement by CDF, we analyse these and other low-energy observables in the framework of the MSSM at large tan(beta). We show…
We examine experimental constraints on scharm-stop flavor mixing in the minimal supersymmetric standard model, which arise from the experimental bounds on squark and Higgs boson masses, the precision measurements of W-boson mass and the…
We study the predictions for BR(mu-> e+gamma) and BR(tau-> e,mu+gamma) in a class of recently proposed horizontal SU(2) model that leads to a 3 X 2 seesaw model for neutrino masses. We consider two such models and obtain the correct…
Using soft-collinear effective theory we describe at leading order in 1/m_b all the semi-inclusive hadronic B -> XM decays near the endpoint, where an energetic light meson M recoils against an inclusive jet X. We also include the decays…
We assess the impact of the very recent measurement of the top-quark mass by the CMS Collaboration on the fit of electroweak data in the Standard Model and beyond, with particular emphasis on the prediction for the mass of the W boson. We…
We discuss how models of electroweak symmetry breaking based on strong dynamics lead to observable contributions to the Z-boson decay width to bbbar pairs even in the absence of any extended sector responsible for dynamical generation of…
A recent theoretical model predicts that the modification of quark distributions in the nuclear medium (EMC effect) depends on the flavor of the quarks. We investigate $W$-boson production in proton-nucleus collision as a possible tool to…
Recent experiments suggest that certain B -> pi K branching ratios are inconsistent with the standard model expectations. We show that a flavor-changing Z' provides a solution to the problem. Electroweak penguin amplitudes are enhanced by…
The mixing of neutral mesons is sensitive to some of the highest scales probed in laboratory experiments. In light of the planned LHCb Upgrade II, a possible upgrade of Belle II, and the broad interest in flavor physics in the tera-$Z$…
A complete discussion of tree-level flavor-changing effects in the Randall-Sundrum (RS) model with brane-localized Higgs sector and bulk gauge and matter fields is presented. The bulk equations of motion for the gauge and fermion fields,…
Motivated by the large discrepancy of CP-violating phase in $\bar{B}_s-B_s$ mixing between the experimental data and the Standard Model prediction, we pursue possible solutions within a family non-universal $Z^{\prime}$ model. Within such a…
Leptophobic Z^\prime gauge boson appears naturally in many grand unified theories, such as flipped SU(5) or string-inspired E_6 models. This elusive particle easily escapes the direct/indirect detections because it does not couple to…
Certain string-inspired Z' models have non-universal interactions to three families of fermions and induced tree-level flavor-changing couplings. We use recent results on B_s-anti-B_s mixing to constrain the size of the flavor-changing…