论文标题
$ b^+/b^0 $生产比在$ e^+e^ - $ collisions在$υ（4S）$ resonance $ b \ rightarrow j/ψ（\ ell \ ell \ ell）k $衰减
Measurement of the $B^+/B^0$ production ratio in $e^+e^-$ collisions at the $Υ(4S)$ resonance using $B \rightarrow J/ψ(\ell\ell) K$ decays at Belle
论文作者
论文摘要
我们测量$υ（4s）$衰减与$ b^+b^ - $和$ b^0 \ bar {b} {b} {}^0 $使用$ b^+rightarrow j/ψ（\ ell \ ell \ ell \ ell \ ell \ ell \ ell \ ell \ el）k^0 $ j/ψ（\ ell \ ell \ ell）$代表$ j/ψ\ to \ ell^+\ ell^ - $（$ \ ell = e $或$μ$），$ 711 $ fb $^{ - 1} $与Belle Detector的$υ（4S）$共振。我们发现$υ（4S）\ rightArrow b^+b^ - $ for $υ（4S）\ rightArrow b^0 \ bar {b} {}^0 $的衰减率比为$ 1.065 \ pm0.012 \ pm0.012 \ pm pm 0.019 \ pm 0.019 \ pm pm 0.047 $，这是最精确的衡量标准。第一个和第二个不确定性分别是统计和系统的，由于在$ b \至j/ψ（\ ell \ ell）k $中的isospin对称性的假设是系统的。
We measure the ratio of branching fractions for the $Υ(4S)$ decays to $B^+B^-$ and $B^0\bar{B}{}^0$ using $B^+ \rightarrow J/ψ(\ell\ell) K^+$ and $B^0 \rightarrow J/ψ(\ell\ell) K^0$ samples, where $J/ψ(\ell\ell)$ stands for $J/ψ\to \ell^+\ell^-$ ($\ell = e$ or $μ$), with $711$ fb$^{-1}$ of data collected at the $Υ(4S)$ resonance with the Belle detector. We find the decay rate ratio of $Υ(4S) \rightarrow B^+B^-$ over $Υ(4S) \rightarrow B^0\bar{B}{}^0$ to be $1.065\pm0.012\pm 0.019 \pm 0.047$, which is the most precise measurement to date. The first and second uncertainties are statistical and systematic, respectively, and the third uncertainty is systematic due to the assumption of isospin symmetry in $B \to J/ψ(\ell\ell) K$.
