2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/43126We consider the chargino contribution to the CP violation in B \to ϕK_S decay in the minimal supersymmetric standard model at large \tanβ. It is shown that the Wilson coefficient C_{8g} of the chromomagnetic penguin operator can be significantly enhanced by the chargino-mediated diagrams while satisfying other direct/indirect experimental constraints. The enhanced C_{8g} allows large deviation in the CP asymmetry from the standard model prediction.6 pages, 2 figures, talk presented at 2nd International Conference on Flavor PhysicsHigh Energy Physics - Phenomenologytext