The first direct observation of time-reversal (T) violation in the system has been reported by the BaBar Collaboration, employing the method of Bañuls and Bernabéu. Given this, we generalize their analysis of the time-dependent T-violating asymmetry (AT) to consider different choices of CP tags for which the dominant amplitudes have the same weak phase. As one application, we find that it is possible to measure departures from the universality of sin⁡(2β) directly. If sin⁡(2β) is universal, as in the Standard Model, the method permits the direct determination of penguin effects in these channels. Our method, although no longer a strict test of T, can yield tests of the sin⁡(2β) universality, or, alternatively, of penguin effects, of much improved precision even with existing data sets.

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Published in Physics Letter B, v. 754, p. 1-5.

© 2016 The Authors.

This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

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We acknowledge partial support from the U.S. Department of Energy Office of Nuclear Physics under contract DE-FG02-96ER40989.

Open Access funded by SCOAP³ - Sponsoring Consortium for Open Access Publishing in Particle Physics