• help
  • PC | SP
  • JP | EN
          
検索対象：     
報告書番号：
※ 半角英数字
 年 ～ 
 年
全てクリア
前の画面に戻る

Observation of $$tau^- rightarrow pi^- nu_{tau} e^+ e^- $$ and search for $$tau^- rightarrow pi^- nu_{tau} mu^+ mu^-$$

$$tau^- rightarrow pi^- nu_{tau} e^+ e^- $$の観測と$$tau^- rightarrow pi^- nu_{tau} mu^+ mu^-$$の探索

Jin, Y.*; 谷田 聖   ; Belle Collaboration*; 他198名*

Jin, Y.*; Tanida, Kiyoshi; Belle Collaboration*; 198 of others*

We present the first measurements of branching fractions of rare tau-lepton decays, $$tau^- rightarrow pi^- nu_{tau} ell^+ ell^-$$ ($$ell = e$$ or $$mu$$), using a data sample corresponding to 562 fb$$^{-1}$$ collected at a center-of-mass energy of 10.58 GeV with the Belle detector at the KEKB asymmetric-energy $$e^+ e^-$$ collider. The $$tau^- rightarrow pi^- nu_tau e^+ e^-$$ decay is observed for the first time with 7.0$$sigma$$ significance. The partial branching fraction determined by the structure-dependent mechanisms mediated by either a vector or an axial-vector current for the mass region $$M_{pi e e} > 1.05$$ GeV/$$c^2$$ is measured to be $$mathcal{B}(tau^-rightarrow pi^- nu_tau e^+ e^-)[M_{pi^- e^+ e^-} > 1.05~{rm GeV}/c^2] = (5.90 pm 0.53 pm 0.85 pm 0.11) times 10^{-6}$$, where the first uncertainty is statistical, the second is systematic, and the third is due to the model dependence. In the full phase space, due to the different detection efficiencies for the structure-dependent mechanisms mediated by axial-vector and vector currents, the branching fraction varies from $$mathcal{B}_{A}(tau^-rightarrow pi^- nu_tau e^+ e^-) = (1.46 pm 0.13 pm 0.21) times 10^{-5}$$ to $$mathcal{B}_{V}(tau^-rightarrow pi^- nu_tau e^+ e^-) = (3.01 pm 0.27 pm 0.43) times 10^{-5}$$, respectively. An upper limit is set on the branching fraction of the $$tau^- rightarrow pi^- nu_tau mu^+ mu^-$$ decay, $$mathcal{B}(tau^-rightarrow pi^- nu_tau mu^+ mu^-) < 1.14 times 10^{-5}$$, at the 90% confidence level.

使用言語

 :

English

掲載資料名

 :

Physical Review D

巻

 :

100

号

 :

7

ページ数

 :

p.071101_1 - 071101_9

発行年月

 :

2019/10

発表会議名

 :

開催年月

 :

開催都市

 :

開催国

 :

キーワード

 :

no keyword

特許データ

 :

PDF

 :


論文URL

 :

https://doi.org/10.1103/PhysRevD.100.071101

研究データの公開先DOI

 :

使用施設

 :

広報プレスリリース

 :

論文解説記事
(成果普及情報誌)

 :

受委託・共同研究相手機関

 :

高エネルギー加速器研究機構

Access

 :

- Accesses

InCites™

 :

パーセンタイル：20.12

分野：Astronomy & Astrophysics

Altmetrics

 :

[CLARIVATE ANALYTICS], [WEB OF SCIENCE], [HIGHLY CITED PAPER & CUP LOGO] and [HOT PAPER & FIRE LOGO] are trademarks of Clarivate Analytics, and/or its affiliated company or companies, and used herein by permission and/or license.

前の画面に戻る