T-violating asymmetry references used by the Charm Subgroup


NOTE:
The T violation asymmetry is obtained using triple-product correlations and assuming the validity of the CPT theorem. Triple-product correlations of the form a • (b x c), where a, b, and c are spins or momenta, are odd under time reversal T. For example, in the decay mode D0 → K+ K- π+ π-, C_T = P(K+) • (P(π+) x P(π-)) is a T-odd correlation computed using the momenta of the daughter particles. The corresponding quantity for D0 is C_Tbar = P(K-) • (P(π-) x P(π+)). The asymmetry A_T = [Γ(C_T>0) - Γ(C_T<0)]/[Γ(C_T>0) + Γ(C_T<0)] would, in the absence of a strong phase, test for T violation in D0 decays, where the Γ's are partial widths. Defining A_Tbar = [Γ(-C_Tbar>0) - Γ(-C_Tbar<0)]/[Γ(-C_Tbar>0) + Γ(-C_Tbar<0)] for D0, the asymmetry A_Tviol = (A_T - A_Tbar)/2 tests for T violation even with non-zero strong phases.

References:

E. Golowich and G. Valencia, Phys. Rev. D 40, 112 (1989).
I.I. Bigi, Proceedings of KAON2001, 417 (2001).
W. Bensalem and D. London, Phys. Rev. D 64, 116003 (2001).
W. Bensalem et al., Phys. Rev. D 66, 094004 (2002).
W. Bensalem et al., Phys. Lett. B 538, 309 (2002).





T-violating asymmetries in D0 decay-rates

Year Experiment T-violating Asymmetry in the decay mode D0 to K+K-π+π- A_Tviol = (A_T - A_Tbar)/2
2010 BABAR P. del Amo Sanchez et al. (BABAR Collab.), Phys. Rev. D81, 111103 (2010). +0.0010 ± 0.0051 ± 0.0044
2005 FOCUS J.M. Link et al. (FOCUS Collab.), Phys. Lett. B 622, 239 (2005). +0.010 ± 0.057 ± 0.037
. . COMBOS average +0.0011 ± 0.0067





T-violating asymmetries in D+ decay-rates

Year Experiment T-violating Asymmetry in the decay mode D0 to K+K-π+π- A_Tviol = (A_T - A_Tbar)/2
2011 BABAR J.P. Lees et al. (BABAR Collab.), arXiv:1105.4410 (2011). -0.0120 ± 0.0100 ± 0.0046
2005 FOCUS J.M. Link et al. (FOCUS Collab.), Phys. Lett. B 622, 239 (2005). +0.023 ± 0.062 ± 0.022
. . COMBOS average -0.0110 ± 0.0109





T-violating asymmetries in Ds+ decay-rates

Year Experiment T-violating Asymmetry in the decay mode Ds+ to K0sK+π+π- A_Tviol = (A_T - A_Tbar)/2
2011 BABAR J.P. Lees et al. (BABAR Collab.), arXiv:1105.4410 (2011). -0.0136 ± 0.0077 ± 0.0034
2005 FOCUS J.M. Link et al. (FOCUS Collab.), Phys. Lett. B 622, 239 (2005). -0.036 ± 0.067 ± 0.023
. . COMBOS average -0.0139 ± 0.0084




Last modified 16 Jun 2011. Send comments to D. Pedrini