Related papers: Rare B Decays with a HyperCP Particle of Spin One
Rare decays are flavour changing neutral current processes that are loop-suppressed in the Standard Model (SM). New particles in SM extensions can therefore give significant contributions, modifying branching fractions and angular…
Motivated by renewed evidence for new physics in $b \to s\ell\ell$ transitions in the form of LHCb's new measurements of theoretically clean lepton-universality ratios and the purely leptonic $B_s\to\mu^+\mu^-$ decay, we quantify the…
A search for the rare decays $B^0_s \to\mu^+\mu^-$ and $B^0 \to\mu^+\mu^-$ is performed at the LHCb experiment. The data analysed correspond to an integrated luminosity of 1 fb$^{-1}$ of $pp$ collisions at a centre-of-mass energy of 7 TeV…
We study rare leptonic decays of vector $B$ mesons in the scalar leptoquark and family non-universal $Z^\prime$ models. We constrain these new couplings by using the measured branching fractions of $B_{s,d} \to \mu^+ \mu^-$ processes and…
Using updated measurements and SU(3)-breaking form factors, we have a detailed look at the B_d -> pi^+ pi^-, B_s -> K^+ K^- and B_d -> pi^\mp K^\pm, B_s -> pi^\pm K^\mp systems. The corresponding decays are related to each other by the…
The New Physics (NP) effects are studied in the rare baryonic decay $\Lambda_b \to \Lambda (\to p\pi^-)\ell^{+}\ell^{-}$, with unpolarized $\Lambda_b$ using most general model independent approach by introducing new axial(vector),…
We study the phenomenology of light scalars of masses $m_1$ and $m_2$ coupling to heavy flavour-violating vector bosons of mass $m_V$. For $m_{1,2}\lesssim $ few GeV, this scenario triggers the rare $B$ meson decays $B_s^0\to 3\mu^+…
This review summarizes the current experimental results on rare B0_(s) -> mu+mu- decays of the Tevatron experiments CDF and D0, and the LHC experiments ATLAS, CMS and LHCb. The experimental branching fraction upper limits for the B0_s ->…
A wealth of new physics models which are motivated by questions such as the nature of dark matter, the origin of the neutrino masses and the baryon asymmetry in the universe, predict the existence of hidden sectors featuring new particles.…
The decays $B \to PP$, where $P$ denotes a pseudoscalar meson, are analyzed, with emphasis on charmless final states. Numerous triangle relations for amplitudes hold within SU(3) symmetry, relating (for example) the decays $B^+ \to \pi^+…
The interplay of experiment and theory is explored in the context of current data on b and c decay. Measurements of |Vcb| and |Vub| are extracted from existing data. Conservative estimates give |Vcb|=(42.4 +/- 1.2{exp} +/- 2.3{thy})x10^{-3}…
We use spin correlations to constrain anomalous $\tau$-lepton couplings at the LHC including its anomalous magnetic moment, electric dipole moment and weak dipole moments. Single spin correlations are ideal to probe interference terms…
We present results on semileptonic B decays obtained with the BABAR detector. The large data set accumulated at the PEP-II asymmetric-energy B-Factory allows a new measurement technique, where the hadronic decay of one B meson is fully…
We investigate the decays of $B$ mesons, i.e., $B_d$, $B_s$, $B^+$, and their antiparticles, to two light vector mesons ($B \to V_1V_2$), focusing on the implications of SU(2) U-spin symmetry, which relates $\Delta S = 0$ and $\Delta S = 1$…
We outline a general strategy for measuring spins, couplings and mixing angles in the case of a heavy partner decay chain terminating in an invisible particle. We consider the common example of a new scalar or fermion D decaying…
The rare Hyperon decay $\Sigma^+ \to p \ell^+ \ell^-$ is an $s \to d$ flavour changing neutral current process, which is highly suppressed within the Standard Model, and is therefore sensitive to new physics. Due to recent improvements in…
We have just entered a new round in the testing of the flavour sector of the Standard Model through high-precision measurements of B-meson decays. A particularly exciting aspect is the exploration of the B_s-meson system at LHCb. We focus…
We search for the rare decay $B^{+}\rightarrow K^{+}\nu\bar{\nu}$ in a $362\ \rm{fb}^{-1}$ sample of electron-positron collisions at the $\Upsilon(4S)$ resonance collected with the Belle II detector at the SuperKEKB collider. We use the…
Within the Standard Model, the branching fraction of the rare decay $B_s\to K^0\bar K^0$ is related to other decay rates and CP asymmetries through the approximate $SU(3)$ flavor symmetry of the strong interactions and the heavy-quark…
Motivated by the large branching ratios observed for the process $B\to\eta^{\prime}K$, we examine critically all the ingredients that go into estimates of B decays into two light pseudoscalars. Within factorization approximation, we examine…