Reconstruction of Ds+- mesons with the CMS experiment

The CMS experiment at the LHC observes the products of the proton-proton collisions at an energy in the center of mass system sqrt(s)=13TeV. In these collisions a large number of particles are produced: among them, B mesons are particularly interesting; they're composed of a b (beauty) quark and a light quark. In the decay of B mesons Ds+- are often produced: they're composed of a quark c and a quark s and they decay in turn. The reconstruction of the decay of Ds+- mesons in final states with kaons (K) and pions is useful in the study of the properties of B mesons. In this work a preliminary study is done, regarding the reconstruction of Ds+- mesons decay in the Phi pi+- channel, followed by the cascade decay Phi->K+K-