Measurement of the CKM angle \u03b3 and {B}_s^0hbox{-} {overline{B}}_s^0 mixing frequency with {B}_s^0to {D}_s^{mp }{h}^{pm }{pi}^{pm }{pi}^{mp } decays

Abstract

The CKM angle γ is measured for the first time from mixing-induced CP violation between {B}_s^0to {D}_s^{mp }{K}^{pm }{pi}^{pm }{pi}^{mp } and {overline{B}}_s^0to {D}_s^{pm }{K}^{mp }{pi}^{mp }{pi}^{pm } decays reconstructed in proton-proton collision data corresponding to an integrated luminosity of 9 fb−1 recorded with the LHCb detector. A time-dependent amplitude analysis is performed to extract the CP-violating weak phase γ − 2βs and, subsequently, γ by taking the {B}_s^0hbox{-} {overline{B}}_s^0 mixing phase βs as an external input. The measurement yields γ = (44 ± 12)° modulo 180°, where statistical and systematic uncertainties are combined. An alternative model-independent measurement, integrating over the five-dimensional phase space of the decay, yields gamma =left({44}_{-13}^{+20}right){}^{circ} modulo 180°. Moreover, the {B}_s^0hbox{-} {overline{B}}_s^0 oscillation frequency is measured from the flavour-specific control channel {B}_s^0to {D}_s^{-}{pi}^{+}{pi}^{+}{pi}^{-} to be ∆ms = (17.757 ± 0.007(stat) ± 0.008(syst)) ps−1, consistent with and more precise than the current world-average value.