The first direct measurement of the absolute branching fraction of Σ+ → Λe+νe is reported based on an e+e− annihilation sample of (10087 pm 44) Jpsi events collected with the BESIII detector at sqrt(s)=3.097 GeV. The branching fraction is determined to be B(Σ → Λe+ νe) = (2.93 pm 0.74stat pm 0.13syst) x 10^(-5), which is the most precise measurement obtained in a single experiment to date and also the first result obtained at a collider experiment. Combining this result with the world average B(Σ−→Λe−ν ̄e) of BðΣ → Λe ν ̄eÞ and the lifetimes of Σ+ , the ratio is determined to be 1.06 pm 0.28, which is within 1.8 standard deviations of the value expected in the absence of second-class currents.

First direct measurement of the absolute branching fraction of Σ+→Λe+νe

Garzia, I.;Scodeggio, M.;
2023

Abstract

The first direct measurement of the absolute branching fraction of Σ+ → Λe+νe is reported based on an e+e− annihilation sample of (10087 pm 44) Jpsi events collected with the BESIII detector at sqrt(s)=3.097 GeV. The branching fraction is determined to be B(Σ → Λe+ νe) = (2.93 pm 0.74stat pm 0.13syst) x 10^(-5), which is the most precise measurement obtained in a single experiment to date and also the first result obtained at a collider experiment. Combining this result with the world average B(Σ−→Λe−ν ̄e) of BðΣ → Λe ν ̄eÞ and the lifetimes of Σ+ , the ratio is determined to be 1.06 pm 0.28, which is within 1.8 standard deviations of the value expected in the absence of second-class currents.
2023
Ablikim, M.; Achasov, M.  N.; Adlarson, P.; Aliberti, R.; Amoroso, A.; An, M.  R.; An, Q.; Bai, Y.; Bakina, O.; Ferroli, R. Baldini; Balossino, I.; Ba...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11392/2530484
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