Measurement of the Absolute Branching Fraction for Λ<i><sub>c</sub></i><SUP>+</SUP> → Λ<i>e</i><SUP>+</SUP>ν<i><sub>e</sub></i>


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Ablikim M., Achasov M. N., Ai X. C., Albayrak O., Albrecht M., Ambrose D. J., ...More

PHYSICAL REVIEW LETTERS, vol.115, no.22, 2015 (SCI-Expanded) identifier identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 115 Issue: 22
  • Publication Date: 2015
  • Doi Number: 10.1103/physrevlett.115.221805
  • Journal Name: PHYSICAL REVIEW LETTERS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Bursa Uludag University Affiliated: No

Abstract

We report the first measurement of the absolute branching fraction for Lambda(+)(c) -> Lambda e(+)nu(e). This measurement is based on 567 pb(-1) of e(+)e(-) annihilation data produced at root s = 4.599 GeV, which is just above the Lambda(+)(c)Lambda(-)(c) threshold. The data were collected with the BESIII detector at the BEPCII storage rings. The branching fraction is determined to be B(Lambda(+)(c) -> Lambda e(+)nu(e)) = [3.63 +/- 0.38(stat) +/- 0.20(syst)] %, representing a significant improvement in precision over the current indirect determination. As the branching fraction for Lambda(+)(c) -> Lambda e(+)nu(e) is the benchmark for those of other Lambda(+)(c) semileptonic channels, our result provides a unique test of different theoretical models, which is the most stringent to date.