Using e+e-→Λc+Λc- production from a 567 pb-1 data sample collected by BESIII at 4.6 GeV, a full angular analysis is carried out simultaneously on the four decay modes of Λc+→pKS0, Λπ+, ς+π0, and ς0π+. For the first time, the Λc+ transverse polarization is studied in unpolarized e+e- collisions, where a nonzero effect is observed with a statistical significance of 2.1σ. The decay asymmetry parameters of the Λc+ weak hadronic decays into pKS0, Λπ+, ς+π0 and ς0π+ are measured to be 0.18±0.43(stat)±0.14(syst), -0.80±0.11(stat)±0.02(syst), -0.57±0.10(stat)±0.07(syst), and -0.73±0.17(stat)±0.07(syst), respectively. In comparison with previous results, the measurements for the Λπ+ and ς+π0 modes are consistent but with improved precision, while the parameters for the pKS0 and ς0π+ modes are measured for the first time.

Measurements of weak decay asymmetries of Λc+ →p Ks0, Λπ+, ς+π0, and ς0π+

Pacetti S.;
2019

Abstract

Using e+e-→Λc+Λc- production from a 567 pb-1 data sample collected by BESIII at 4.6 GeV, a full angular analysis is carried out simultaneously on the four decay modes of Λc+→pKS0, Λπ+, ς+π0, and ς0π+. For the first time, the Λc+ transverse polarization is studied in unpolarized e+e- collisions, where a nonzero effect is observed with a statistical significance of 2.1σ. The decay asymmetry parameters of the Λc+ weak hadronic decays into pKS0, Λπ+, ς+π0 and ς0π+ are measured to be 0.18±0.43(stat)±0.14(syst), -0.80±0.11(stat)±0.02(syst), -0.57±0.10(stat)±0.07(syst), and -0.73±0.17(stat)±0.07(syst), respectively. In comparison with previous results, the measurements for the Λπ+ and ς+π0 modes are consistent but with improved precision, while the parameters for the pKS0 and ς0π+ modes are measured for the first time.
2019
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11391/1460350
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