arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 0708.2260hep-ex
收藏

用强子B标记搜索B+ --> tau+ nu

A search for B+ --> tau+ nu with Hadronic B tags

The BABAR Collaboration, B. Aubert

摘要:

我们利用SLAC PEP-II B工厂的BABAR探测器在Upperdance(4S)共振处收集的$383 \times 10^{6}}$ BBbar对来搜索B^+ --> tau^+ nu衰变。我们选择一个强子衰变模式($B^- \to D^{(*)0} X^-$)中具有一个完全重建的标签B的事件样本,并检查事件的其余部分以寻找B^+ --> tau^+ nu衰变。我们以下列模式识别τ轻子:τ ^+ --> e^+ nu nu,τ ^+ --> mu^+ nu nu,τ ^+ --> pi^+ nu和τ ^+ --> pi^+ pi^0 nu。我们在数据中发现了2.2 sigma的超额,并测量了B(B+ --> tau^+ nu)=(1.8^{+0.9}_{-0.8}(stat.)\pm 0.4(bkg.系统)\pm 0.2(其他系统))\times 10^{4}。我们计算了B介子衰变常数f_{B}和|V_{ub}|成为f_{B}| V_{ub}| =(10.1^{+2.3}_{-2.5}(统计)^ {+1.2}_{-1.5}(系统))\times 10^{-4} GeV

英文摘要:

We present a search for the decay B^+ --> tau^+ nu using $383 \times 10^{6}}$ BBbar pairs collected at the Upsilon(4S) resonance with the BABAR detector at the SLAC PEP-II B Factory. We select a sample of events with one completely reconstructed tag B in a hadronic decay mode ($B^- \to D^{(*)0} X^-$), and examine the rest of the event to search for a B^+ --> tau^+ nu decay. We identify the tau lepton in the following modes: tau^+ --> e^+ nu nu,tau^+ --> mu^+ nu nu, tau^+ --> pi^+ nu and tau^+ --> pi^+ pi^0 nu. We find a 2.2 sigma excess in data and measure a branching fraction of B(B+ --> tau^+ nu) = (1.8^{+0.9}_{-0.8}(stat.) \pm 0.4(bkg. syst.) \pm 0.2 (other syst.)) \times 10^{4}. We calculate the product of the B meson decay constant f_{B} and |V_{ub}| to be f_{B} |V_{ub}| = (10.1^{+2.3}_{-2.5}(stat.)^{+1.2}_{-1.5}(syst.))\times10^{-4} GeV

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑