학술논문

Determination of $\pi\pi$ scattering lengths from measurement of $\pi^+\pi^-$ atom lifetime
Document Type
Working Paper
Source
Physics Letters B 704 (2011) 24
Subject
High Energy Physics - Experiment
High Energy Physics - Phenomenology
Language
Abstract
The DIRAC experiment at CERN has achieved a sizeable production of $\pi^+\pi^-$ atoms and has significantly improved the precision on its lifetime determination. From a sample of 21227 atomic pairs, a 4% measurement of the S-wave $\pi\pi$ scattering length difference $|a_0-a_2| = (.0.2533^{+0.0080}_{-0.0078}|_\mathrm{stat}.{}^{+0.0078}_{-0.0073}|_\mathrm{syst})M_{\pi^+}^{-1}$ has been attained, providing an important test of Chiral Perturbation Theory.
Comment: 6 pages, 6 figures