New constraints on CPT symmetry violation in charm mesons

Abstract

Small CPT-violating effects are admissible in several theories beyond the Standard Model of interactions. We analyze experimental data obtained with neutral flavored meson mixing and place bounds on the scale of such phenomena. The constraints on the CPT-violating parameter z are derived by reinterpreting the LHCb measurement of the time-dependent asymmetry in the Cabbibo-favored D0→K−π+ and D0¯→K+π− decay rates. The bounds provided in this paper are 2 orders of magnitude stricter compared to the results obtained by the FOCUS Collaboration. Among other constraints, we report bounds on the differences in the decay widths and masses of the neutral D meson flavor states at a 95% confidence level. The decay width difference is bounded by (−4.7<δΓD<2.1)×10−16 GeV. The mass difference lies within (−2.0<δmD<2.0)×10−15 GeV for 95% of arg(z) values. The paper includes an assessment of the influence of CP violation on the results and a discussion of the future prospects. Published by the American Physical Society 2024