Publication Date:
2021-05-01
Description:
The decays D → K−π+π+π− and D → K−π+π0 are studied in a sample of quantum-correlated $$ Doverline{D} $$ D D ¯ pairs produced through the process e+e− → ψ(3770) → $$ Doverline{D} $$ D D ¯ , exploiting a data set collected by the BESIII experiment that corresponds to an integrated luminosity of 2.93 fb−1. Here D indicates a quantum superposition of a D0 and a $$ {overline{D}}^0 $$ D ¯ 0 meson. By reconstructing one neutral charm meson in a signal decay, and the other in the same or a different final state, observables are measured that contain information on the coherence factors and average strong-phase differences of each of the signal modes. These parameters are critical inputs in the measurement of the angle γ of the Unitarity Triangle in B− → DK− decays at the LHCb and Belle II experiments. The coherence factors are determined to be RK3π = $$ {0.52}_{-0.10}^{+0.12} $$ 0.52 − 0.10 + 0.12 and $$ {R}_{K{pi pi}^0} $$ R K ππ 0 = 0.78 ± 0.04, with values for the average strong-phase differences that are $$ {delta}_D^{K3pi }=left({167}_{-19}^{+31}
ight){}^{circ} $$ δ D K 3 π = 167 − 19 + 31 ° and $$ {delta}_D^{K{pi pi}^0}=left({196}_{-15}^{+14}
ight){}^{circ} $$ δ D K ππ 0 = 196 − 15 + 14 ° , where the uncertainties include both statistical and systematic contributions. The analysis is re-performed in four bins of the phase-space of the D → K−π+π+π− to yield results that will allow for a more sensitive measurement of γ with this mode, to which the BESIII inputs will contribute an uncertainty of around 6°.
Print ISSN:
1126-6708
Electronic ISSN:
1029-8479
Topics:
Physics
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