CP violation in psi(2S) -> J/psi pi pi processes

Abstract

We propose to search for CP-violating effects in the decay psi(2S)->J/psi+pi+pi. The scheme has the advantage that one does not need to track two or more CP-conjugate processes. Model independent amplitudes are derived for this purpose. The fact that leading CP violating terms are O(k) under low energy expansion and the processes are flavor disconnected make the measurement of these CP breaking parameters practical. Our results can be extended to the case of Upsilon(2S)->Upsilon(1S)+pi+pi and Upsilon(3S)->Upsilon(2S)+pi+pi straightforwardly.