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EPS-HEP / Time-dependent CP violation in charmless b decays at LHCb (355+357)

In the B meson sector, measurements of weak phases not associated with Vub are obtained through time-dependent, flavour-tagged analyses involving B-Bbar mixing. In addition to new phases that may enter the mixing loop, charmless B decays have an additional mechanism for unknown particles to induce deviations from the Standard Model expectation due to the sizeable contribution to these decays from penguin topologies. We present the most recent studies of time-dependent CP violation in charmless B decays at the LHCb experiment, including Bs -> phi phi, one of the “golden channels” for New Physics searches. merged with Polarisation and direct CP violation measurements of charmless B -> VV decays at LHCb In the heavy-quark limit, the fraction of longitudinal polarisation in charmless VV final states (where V is a vector meson) is expected to be close to unity. However, experimental measurements show that some decays with a sizeable penguin contribution can be inconsistent with this naive expectation, referred to as the “polarisation puzzle”. Furthermore, charmless b-hadron decays are CKM-suppressed in the Standard Model, leaving their tree-amplitude strengths at levels comparable to that of competing loop amplitudes. Hence, new particles not foreseen in the Standard Model that appear in these loops may alter the physical observables of these decays from their Standard Model expectations. We present the latest measurements on the observables fL and Acp in B -> VV final states including B0 -> K*0 rho0, K*0 K*0bar and Bs -> phi phi, K*0 K*0bar at LHCb.

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