Related papers: Rare B Decays with a HyperCP Particle of Spin One

A search for rare $B \rightarrow D \mu^+ \mu^-$ decays is performed using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb$^{-1}$. No significant signals are observed in the…

Unparticle contributions to the recently measured decay mode $B_s\to\mu^+\mu^-$ are analyzed. We consider only the scalar unparticles because vector unparticles are expected to provide negligible contributions. Assuming that the relevant…

We present a systematic analysis for the rare baryonic exclusive decays of $\Lambda_b\to\Lambda l^+ l^- (l=e,\mu,\tau)$. We study the differential decay rates and the di-lepton forward-backward, lepton polarization and various CP…

We report on a search for Bs->mu+mu- and Bd->mu+mu- decays in ppbar collisions at sqrt(s)=1.96 TeV using 171 pb-1 of data collected by the CDF II experiment at the Fermilab Tevatron Collider. The decay rates of these rare processes are…

Rare $B$-meson decays, suppressed in the Standard Model (SM) by the GIM mechanism, are sensitive probes of new physics. In particular, loop-level $b \to s$ transitions can reveal effects of heavy virtual particles such as vector-like quarks…

A joint measurement is presented of the branching fractions $B^0_s\to\mu^+\mu^-$ and $B^0\to\mu^+\mu^-$ in proton-proton collisions at the LHC by the CMS and LHCb experiments. The data samples were collected in 2011 at a centre-of-mass…

A search for the decays Bs -> mu+ mu- and B0 -> mu+ mu- is performed with 0.37 fb^-1 of pp collisions at sqrt{s} = 7 TeV collected by the LHCb experiment in 2011. The upper limits on the branching fractions are BR (Bs -> mu+ mu-) < 1.6 x…

We found that spin-one new light particle exchanges are strongly bounded by high-energy and small momentum transfer np elastic scattering data; the analogous bound for a scalar particle is considerably weaker, while for a pseudoscalar…

To explain the anomalously large decay rate of $\Sigma^+\to p+\mu^+\mu^-$, it was proposed that a new mechanism where a light CP-odd pseudoscalar boson of $m_{A_1^0}=214.3$ MeV makes a crucial contribution. Later, some authors have studied…

Decays of the kind $B^0_{s,d}\to\ell^+\ell^-$ belong to the most favourable processes for probing the flavour structure of the Standard Model, with outstanding sensitivity to new (pseudo)-scalar contributions. While the branching ratio of…

The B-meson system is an interesting probe for the exploration of strong interactions, the quark-flavour sector of the Standard Model, and the search for new physics. In this programme, non-leptonic B decays, which are particularly…

We explore the possibility of using CP violation in B decays to detect the presence of physics beyond the Standard Model. We first study the possibility of new physics in the $B-\bar B$ mixing amplitude. We discuss a construction to extract…

We study the rare $\Lambda_b\to\Lambda\mu^+\mu^-$ decay in the Standard Model and beyond. Beyond the Standard Model we include new vector and axial-vector operators, scalar and pseudo-scalar operators, and tensor operators in the effective…

Top pair events provide a source of $b\bar{b}$ pairs, which can be used to probe CP violation in heavy-flavour mixing and decay. In events where one of the $W$ bosons decays leptonically to an electron or muon, the charge of the $W$ boson…

We examine recent extensions of the standard model with an up-type vectorlike isosinglet T quark that mixes dominantly with the top quark. We take under scrutiny the nondecoupling effects which may reveal such a new heavy fermion through…

The Belle and Belle II experiments have collected a $1.6\,\mathrm{ab}^{-1}$ sample of $e^+e^-$ collision data at center-of-mass energies near the $\Upsilon(nS)$ resonances. We conduct searches for transitions from the spin-singlet…

Beyond Standard Model scenarios addressing the flavor puzzle and the hierarchy problem generally predict dominant new physics couplings with fermions of the third generation. In this Letter, we explore the collider and astrophysical…

New heavy vector bosons and light scalars are predicted in a plethora of models of new physics. In particular, in new strongly interacting sectors they play the role of the $\rho$ and $\pi$ mesons in QCD. We show that some of their…

A search for the Bs->mumu and Bd->mumu decays is presented using ~300 pb-1 of pp collisions at sqrt{s} = 7 TeV collected by the LHCb experiment at the Large Hadron Collider at CERN. The measured upper limit for the branching ratio of the…

The most recent measurements of the observables $R_{D^{(*)}}$ are in tension with the Standard Model offering hints of New Physics in $b\rightarrow c \ell \bar{\nu}_{\ell}$ transitions. Motivated by these results, in this work we present an…