论文标题
分支分数的测量$ \ MATHCAL {b}（\ bar {b} {}^0 \ 0 \ to d^{*+}π^ - ）$和$ \ Mathcal {b}（\ bar {b}
Measurements of the branching fractions $\mathcal{B} (\bar{B}{}^0 \to D^{*+} π^-)$ and $\mathcal{B} (\bar{B}{}^0 \to D^{*+} K^-)$ and tests of QCD factorization
论文作者
论文摘要
使用$（771.6 \ pm 10.6）\ times 10^6 $ $ $ b \ bar {b} $ meson对在kekb $ e^+ e^ - $ collider上记录的belle实验记录，我们报告了分支分数$ \ \ \ nathcal {b} {b}（\ bar {b}^b}^02 pm { \ pm 0.09）\ times 10^{ - 3} $和$ \ Mathcal {b}（\ bar {b}^0 \ to d^{*+} k^ - ）=（2.22 \ pm 0.06 \ pm 0.08）\ pm pm 0.08）\ times 10^{ - 4} $;引用的不确定性分别是统计和系统的。还提出了对这些分支分数比率的测量值，$ \ MATHCAL {r} _ {k /π} = \ Mathcal {b}（\ bar {b} \ to d^{*+}+}+} k^ - ） /\ Mathcal {b} \ pm 0.24 \ pm 0.13）\ times 10^{ - 2} $，其中由于$ d^{*+} $ MESON重建导致的系统不确定性取消。此外，我们根据$ \ bar {b} \至d^{*+} h^ - $和$ \ bar {b} \ do d^{*+} \ ell^ - $ n- $ n- $ n- $ n- $ n- $ n- $ n- $ n- $ n- $ n- $ n- $ n- $ n- $ n- The parameters $|a_1(h)|$ are measured to be $|a_1(π)|= 0.884 \pm 0.004 \pm 0.003 \pm 0.016$ and $|a_1(K)|=0.913 \pm 0.019 \pm 0.008 \pm 0.013$, where the last uncertainties account for all external inputs.这些值大约比理论预测预期的$ 15 \％$ $。随后，通过测量亲质和kaons的比率，$ | a_1（k）|^2/ | a_1（π）|^2 = 1.066 \ pm 0.042 \ pm 0.018 \ pm 0.018 \ pm 0.023 $，以及针对不同颗粒的物种，来测试味道$ su（3）$对称性。该比率与团结一致，因此在$ 5 \％$ precision级别上没有证据表明$ su（3）$对称破坏效果。
Using $(771.6 \pm 10.6) \times 10^6$ $B\bar{B}$ meson pairs recorded by the Belle experiment at the KEKB $e^+ e^-$ collider, we report the branching fractions $\mathcal{B}(\bar{B}^0 \to D^{*+} π^-) = (2.62 \pm 0.02 \pm 0.09)\times 10^{-3}$ and $\mathcal{B}(\bar{B}^0 \to D^{*+} K^-) = (2.22 \pm 0.06 \pm 0.08)\times 10^{-4}$; the quoted uncertainties are statistical and systematic, respectively. A measurement of the ratio of these branching fractions is also presented, $\mathcal{R}_{K/π}=\mathcal{B}(\bar{B} \to D^{*+}K^-) /\mathcal{B}( \bar{B} \to D^{*+}π^-) = (8.41 \pm 0.24 \pm 0.13)\times 10^{-2}$, where systematic uncertainties due to the $D^{*+}$ meson reconstruction cancel out. Furthermore, we report a new QCD factorization test based on the measured ratios for $\bar{B} \to D^{*+}h^-$ and $\bar{B} \to D^{*+}\ell^-ν$ decays at squared momentum transfer values equivalent to the mass of the $h = π$ or $K$ hadron. The parameters $|a_1(h)|$ are measured to be $|a_1(π)|= 0.884 \pm 0.004 \pm 0.003 \pm 0.016$ and $|a_1(K)|=0.913 \pm 0.019 \pm 0.008 \pm 0.013$, where the last uncertainties account for all external inputs. These values are approximately $15\%$ lower than those expected from theoretical predictions. Subsequently, flavor $SU(3)$ symmetry is tested by measuring the ratios for pions and kaons, $|a_1(K)|^2/ |a_1(π)|^2=1.066 \pm 0.042 \pm 0.018 \pm 0.023$, as well as for different particle species. The ratio is consistent with unity and therefore no evidence for $SU(3)$ symmetry breaking effects is found at the $5\%$ precision level.
