Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userNew results on inclusive $Bto X_{u} ell u$ decay from the Belle experiment
106
0
0.0
(
0
)
Authors
Lu Cao
Ask ChatGPT about the research
No Arabic abstract
We report on the measurement of inclusive charmless semileptonic B decays $B to X_{u} ell u$. The analysis makes use of hadronic tagging and is performed on the full data set of the Belle experiment comprising 772 million $Bbar{B}$ pairs. In the proceedings, the preliminary results of measurements of partial branching fractions and the CKM matrix element $|V_{ub}|$ are presented.
rate research
Read More
This contribution illustrates a new search for the flavor-changing neutral-current decay ${B^+ to K^+ u bar u}$ performed by the Belle II experiment at the SuperKEKB asymmetric-energy electron-positron collider. In this study, a sample corresponding to an integrated luminosity of $63, rm{fb}^{-1}$ collected at the $rm Upsilon(4S)$ resonance and an additional sample of $9, rm{fb}^{-1}$ collected at an energy $60, rm MeV$ below the resonance are used. A novel technique, based on an inclusive tagging method and exploiting the topological features of the ${B^+ to K^+ u bar u}$ decay, is employed and it provides a higher signal efficiency with respect to the methods used in the previous searches. No significant signal is observed. An upper limit of $4.1 times 10^{-5}$ is set on the ${B^+ to K^+ u bar u}$ branching fraction at the $90, %$ confidence level.
I report here recent measurements of observables from the inclusive decays $Bto X_sgamma$ and $Bto X_sell^+ell^-$. Included are measurements of the branching fractions and CP asymmetries for both channels, as well as the forward-backward lepton asymmetry in inclusive $Bto X_sell^+ell^-$ decays, which is the first measurement of this quantity.
We report the recent results of a search for the decay B- --> tau- anti-nu_tau, observations of new resonances X, Y and Z, and the first results from Upsilon(5S) data collected with the Belle detector at KEKB e+e- collider.
We present the results of a search for the rare decays $Bto h uoverline{ u}$, where $h$ stands for $K^+,:K^0_{mathrm{S}},:K^{ast +},:K^{ast 0},:pi^+,:pi^0,:rho^+$ and $rho^{0}$. The results are obtained with $772times10^{6}$ $Boverline{B}$ pairs collected with the Belle detector at the KEKB $e^+ e^-$ collider. We reconstruct one $B$ meson in a semileptonic decay and require a single $h$ meson but nothing else on the signal side. We observe no significant signal and set upper limits on the branching fractions. The limits set on the $Bto K^0_{mathrm{S}} uoverline{ u}$, $B^0to K^{*0} uoverline{ u}$, $Bto pi^+ uoverline{ u}$, $B^0topi^0 uoverline{ u}$, $B^+torho^+ uoverline{ u}$, and $B^0torho^0 uoverline{ u}$ channels are the worlds most stringent.
The trilepton nucleon decay modes $p rightarrow e^+ u u$ and $p rightarrow mu^+ u u$ violate $|Delta (B - L)|$ by two units. Using data from a 273.4 kiloton year exposure of Super-Kamiokande a search for these decays yields a fit consistent with no signal. Accordingly, lower limits on the partial lifetimes of $tau_{p rightarrow e^+ u u} > 1.7 times 10^{32}$ years and $tau_{p rightarrow mu^+ u u} > 2.2 times 10^{32}$ years at a $90 % $ confidence level are obtained. These limits can constrain Grand Unified Theories which allow for such processes.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
