The CP-violating angle γ is the only angle of the unitarity triangle which can be measured via tree-level processes. γ can also be measured indirectly using loop-level processes, which are susceptible to the effects of new physics. An observed discrepancy between the direct and indirect measurements of γ would be evidence for new physics. Reducing the experimental uncertainty on the direct γ measurement is therefore of great interest.
To measure γ, we exploit interference between decays with b → u and b → c quark transitions. One such decay is B0 → DK*0, where D is a superposition of D0 and anti-D0 mesons. An analysis of this mode is presented with D reconstructed in the two-body final states K-π+, K+π-, K+K- and π+π-, and the four-body final states K-π+π-π+, K+π-π+π- and π+π-π+π-. The data sample used corresponds to 5 fb-1 of proton-proton collisions collected by the LHCb experiment. Several observables are measured, including CP asymmetries. These provide constraints on γ as well the amplitude ratio rB and strong phase difference δB between the interfering decays.