Constraints on the CKM angle
and strong phases from
1 Technische Universität München,
Physik Department, 85748 Garching, Germany
2 Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
Received: 31 March 2000 / Published online: 18 May 2000 - © Springer-Verlag 2000
As we pointed out recently, the neutral decays and may provide non-trivial bounds on the CKM angle . In this paper, we reconsider this approach in the light of recent CLEO data, which look very interesting. In particular, the results for the corresponding CP-averaged branching ratios are in favour of strong constraints on , where the second quadrant is preferred. Such a situation would be in conflict with the standard analysis of the unitarity triangle. Moreover, constraints on a CP-conserving strong phase are in favour of a negative value of , which would be in conflict with the factorization expectation. In addition, there seems to be an interesting discrepancy with the bounds that are implied by the charged system: whereas these decays favour a range for that is similar to that of the neutral modes, they point towards a positive value of , which would be in conflict with the expectation of equal signs for and . If future data should confirm this ``puzzle'', it may be an indication for new-physics contributions to the electroweak penguin sector, or a manifestation of large non-factorizable SU(3)-breaking effects.
Copyright Società Italiana di Fisica, Springer-Verlag 2000