Measurement of the Λ hyperon lifetime

Summary, in English

A new, more precise measurement of the Λ hyperon lifetime is performed using a large data sample of Pb-Pb collisions at sNN=5.02 TeV with ALICE. The Λ and Λ¯ hyperons are reconstructed at midrapidity using their two-body weak decay channel Λ→p+π- and Λ¯→p¯+π+. The measured value of the Λ lifetime is τΛ=[261.07±0.37(stat.)±0.72(syst.)] ps. The relative difference between the lifetime of Λ and Λ¯, which represents an important test of CPT invariance in the strangeness sector, is also measured. The obtained value (τΛ-τΛ¯)/τΛ=0.0013±0.0028(stat.)±0.0021(syst.) is consistent with zero within the uncertainties. Both measurements of the Λ hyperon lifetime and of the relative difference between τΛ and τΛ¯ are in agreement with the corresponding world averages of the Particle Data Group and about a factor of three more precise. © 2023 CERN.

• Author: S. Acharya; S. Basu; P. Christiansen; O. Matonoha; A.F. Nassirpour; A. Ohlson; D. Silvermyr; J. Staa; V. Vislavicius; N. Zurlo
• Department/s: Particle and nuclear physics
• Publishing year: 2023
• Language: English
• Publication/Series: Physical Review D
• Volume: 108
• Issue: 3
• Links: http://dx.doi.org/10.1103/PhysRevD.108.032009
• Document type: Journal article
• Publisher: American Physical Society
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 2470-0010