First πK atom lifetime measurement and recent results from the DIRAC experiment
Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Russia
a e-mail: Mikhail.Zhabitsky@jinr.ru
Published online: 26 November 2014
We report evidence for πK atoms production, using 24 GeV/c proton beam from CERN PS interacting with a thin Ni target. We have identified (178 ± 49) πK pairs, which were produced in a bound state — πK atom, which was subsequently broken-up (ionized) in the Ni target. Our analysis yields a first measurement of the πK atom lifetime (2.5−1.8+3.0) fs . This lifetime is connected in a model-independent way to the S-wave isospin-odd πK scattering length |a0−| = 1/3|a1/2 − a3/2| = (0.11−0.04+0.09) Mπ−1 (aI for isospin I).
© Owned by the authors, published by EDP Sciences, 2014
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.