Unbiased $B_s \rightarrow K^+K^-$ lifetime measurement

Two-body charmless B meson decays offer a rich phenomenology to explore the phase structure of the CKM matrix and to search for New Physics beyond the Standard Model. The analysis of the decay $B_s$ is particularly suited to the LHCb experiment which features powerful particle identification detectors. This note presents a measurement of the $B_s$ lifetime which can be linked to the width difference $\Delta \Gamma_s$ as a sensitive probe of New Physics. The $B_s$ events analysed in this study are selected using information from the particle identification sub-detectors which avoid a bias in the reconstructed proper-time spectrum. In the absence of real data, simulated events are used to prepare the measurement.