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