相关论文: B \to X_s \ell^+ \ell^- at Belle
We have measured the branching fraction of the inclusive radiative B meson decay B --> X(s) gamma to be Br(B->X(s)gamma)=(3.36 +/- 0.53(stat) +/- 0.42(sys) +0.50-0.54(th)) x 10^{-4}. The result is based on a sample of 6.07 x 10^6 BBbar…
We present an analysis of the semi-inclusive decays $B_s \to D_s^- X \ell^+ \nu$ and $B_s \to D_s^{*-} X \ell^+ \nu$, where $X$ denotes a final state that may consist of additional hadrons or photons and $\ell$ is an electron or muon. The…
The branching fractions of the decays $B^{+} \to \eta \ell^{+} \nu_{\ell}$ and $B^{+} \to \eta^{\prime} \ell^{+} \nu_{\ell}$ are measured, where $\ell$ is either an electron or a muon, using a data sample of $711\,{\rm fb}^{-1}$ containing…
We report measurements of the ratios of branching fractions for $B \to \bar{D}^{(*)}\pi\ell^+\nu_\ell$ and $B \to \bar{D}^{(*)}\pi^+\pi^-\ell^+\nu_\ell$ relative to $B \to \bar{D}^*\ell^+\nu_\ell$ decays with $\ell = e, \mu$. These results…
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 the first observation of the flavor-changing neutral current decay $B \to K^* \ell^+ \ell^-$ and an improved measurement of the decay $B \to K \ell^+ \ell^-$, where $\ell$ represents an electron or a muon, with a data sample of…
This proceeding summarizes the recent measurements of semileptonic $b\to u$ decays from the Belle experiment. These analyses use the full data set collected at the $\Upsilon(4S)$ resonance at KEKB accelerator complex with a center-of-mass…
Recent results obtained using the data sample of 23.6 fb^-1 collected on the Y(5S) resonance with the Belle detector at the KEKB asymmetric energy e+ e- collider are discussed. Measurements of several B_s^0 decay branching fractions are…
The $b \rightarrow s \gamma$, $b \rightarrow d \gamma$ and $b \rightarrow s \ell^+ \ell^-$ processes are allowed at higher order via the electroweak loop or box diagrams in the Standard model. It is sensitive probe to search for new physics…
We report branching fraction measurements of the decays $B^+\to\eta\ell^+\nu_\ell$ and $B^+\to\eta^\prime\ell^+\nu_\ell$ based on 711~fb$^{-1}$ of data collected near the $\Upsilon(4S)$ resonance with the Belle experiment at the KEKB…
We present a search for the B-> pi e^+ e^- and B-> pi \mu^+ \mu^- decays, with a data sample of 657 million BBbar pairs collected with the Belle detector at the KEKB $e^+e^-$ collider. Signal events are reconstructed from a charged or a…
We report the first observation of the decay $B^+ \to \chi_{c0} K^+$ using 21.3 fb$^{-1}$ of data collected by the Belle detector at the $\Upsilon$(4S) resonance. The preliminary result for the branching fraction is ${\cal{B}}(B^+\to…
We report a measurement of the branching fraction of $B \to K^{\ast}(892)\ell^+\ell^-$ decays, where $\ell^+\ell^- = \mu^+\mu^-$ or $e^+e^-$, using electron-positron collisions recorded at an energy at or near the $\Upsilon(4S)$ mass and…
We report a search for the rare charmless decay $B^+\rightarrow\overline{K}{}^{*0}K^{*+}$ using a data sample of $772\times10^6$ $B\bar{B}$ pairs collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB…
We report a search for the flavor-changing neutral current decay $B \to K^{(*)} \ell^{+} \ell^{-}$ using a 29.1 fb${}^{-1}$ data sample accumulated at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB $e^{+}e^{-}$ storage…
We measure the branching fractions for the decays $\bar{B}^0 \to D^{*+} e^{-} \bar{\nu}_e$ and $\bar{B}^0 \to D^{*+} \mu^{-} \bar{\nu}_\mu$ using $8.70 \pm 0.09~{\rm fb}^{-1}$ of data collected by the Belle II experiment at the SuperKEKB…
We report a measurement of the branching fraction of $B^+ \to \tau^+ \nu_\tau$ decays using a data sample of $772 \times 10^6 B \bar{B}$ pairs, collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy…
We report recent results obtained with the Belle detector using a 23.6 fb^{-1} data sample collected on the Y(5S) resonance at the KEKB asymmetric energy e^+ e^- collider. Inclusive semileptonic B_s^0 -> X^+ l^- \nu decays are studied for…
We report a measurement of the inclusive semileptonic $B_s^0$ branching fraction in a $121~fb^{-1}$ data sample collected near the $\Upsilon(5S)$ resonance with the Belle detector at the KEKB asymmetric energy $e^+ e^-$ collider. Events…
We report results of studies of inclusive $B \to \eta K^+ \pi^-$ and $B \to \eta \pi^+ \pi^-$ decays. Charged conjugates are implied throughout this paper. These are obtained from a data sample containing 386 million $B\bar{B}$ pairs,…