Related papers: Rare decays: A window on new physics
The study of flavour-changing neutral currents (FCNC) gives access to important tests of the Standard Model (SM) and allows to search for hints of beyond the SM phenomena. We present here the study of the very rare decays $B^0\rightarrow…
We report a preliminary study of the branching fractions and $q^2$ distributions of exclusive charmless semileptonic B decays, using events tagged by fully reconstructing one of the $B$ mesons in a hadronic decay mode. These results are…
We report updated measurements of branching fractions ($\mathcal{B}$) and CP-violating charge asymmetries ($\mathcal{A_{\rm CP}}$) for charmless $B$ decays at Belle II, which operates on or near the $\Upsilon$(4S) resonance at the SuperKEKB…
We present measurements of the flavor-changing neutral current decays B -> Kl+l- and B -> K*l+l-, where l+l- is either an e+e- or mu+mu- pair. The data sample comprises 229 X 10^6 Y(4S) -> BBbar decays collected with the BaBar detector at…
This contribution illustrates a new search for the flavor-changing neutral-current decay ${B^+ \to K^+ \nu \bar \nu}$ performed by the Belle II experiment at the SuperKEKB asymmetric-energy electron-positron collider. In this study, a…
Semileptonic decays of $B$ mesons that proceed via $b\rightarrow u$ and $b\rightarrow c$ transitions, as well as rare leptonic $B$ decays, are fertile grounds for probing new physics beyond the Standard Model. The Belle II experiment…
The experimental measurements of flavor-changing neutral-current B-meson decays governed by b --> s + (gamma, l^+ l^-) transitions have entered a new level of precision. Recent results by Belle, CDF, Babar, and LHCb on B -->K^(*) l^+ l^-…
The Belle II experiment at the SuperKEKB energy-asymmetric electron-positron collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. Belle II collected a sample of $362~\mathrm{fb}^{-1}$ at the…
The Belle II experiment will measure the rare decays $B\to K\nu\nu$ and $B\to K^* \nu\nu$ with increased sensitivity which can hence be expected to serve as a very efficient probe of new physics. We calculate the relevant branching ratios…
In this work we study the flavor changing neutral current(FCNC) decays of the top quark, $t\to c\gamma$ and $t\to c g$. The Standard Model, predictions for the branching ratios of these decays are about $\sim 5\times 10^{-14}$, and $\sim…
Studying flavor changing neutral current transitions provides important information that helps searches for physics beyond the standard model. In this paper we report on recent measurements of these transitions using data collected by the…
We report the first search for the flavor-changing neutral-current decays $B \rightarrow X_{s} \nu \bar{\nu}$, where $X_{s}$ is a hadronic system with strangeness equal to 1, in data collected with the Belle~II detector at the SuperKEKB…
We present measurements of $B^{+}\rightarrow\rho^{+}\gamma$ and $B^{0}\rightarrow\rho^{0}\gamma$ decays using a combined data sample of $772 \times 10^6$ $B\overline{B}$ pairs collected by the Belle experiment and $387\times 10^6$…
In this paper, we briefly review results on rare decays of $B$ mesons from the Belle experiment, based on 10.4 fb$^{-1}$ data collected on the $\Upsilon$(4S) resonance. The topics include measurements of Cabibbo suppressed decays $B \to…
We show that the study of CP asymmetries in neutral B-meson decays provides a very sensitive probe of flavour-changing neutral currents (FCNC). We introduce two new angles, $\alpha_{SM}$ and $\beta_{SM}$, whose main feature is that they can…
Recent improved measurements of B decays probing the b->s flavour-changing neutral current have put strong constraints on flavour violation beyond the Standard Model. This talk reviews a model-independent analysis of these decays, which…
Rare flavour-changing neutral-current transitions of the type $s \to d \ell^+\ell^-(\nu\bar\nu)$ and $b \to s \ell^+\ell^-(\nu\bar\nu)$ are analysed in supersymmetric extensions of the Standard Model with generic flavour couplings. It is…
We review the status of the flavour-changing neutral-current processes (FCNC). In particular we discuss: i) Main targets of the field, ii) The theoretical framework for FCNC, iii) Standard analysis of the unitarity triangle, iv)…
The Flavor Changing Neutral Current decays(FCNC) is forbidden at tree level in the Standard Model (SM) and could only contribute through loops. Any direct observation beyond SM expectations could be a good probe of physics beyond SM. BESIII…
This letter presents a search for the rare flavor-changing neutral current process $B^{0}\rightarrow K^{\ast 0}\tau^{+}\tau^{-}$ using data taken with the Belle detector at the KEKB asymmetric energy $e^{+}e^{-}$ collider. The analysis is…