Paper detail

CP violating anomalous tau lepton coupling $\barττV$ via a spin-0 unparticle

The tau is the only known lepton that can decay hadronically. From this class of decays, high precision measurements of several quantities can be extracted: the CKM matrix element $V_{us}$, the mass of the strange quark, etc. Also, as a result of its large variety of decay channels, the study of the tau lepton represents an interesting tool to search for CP violation and other new physics effects. In this work, a spin-0 unparticle is considered and its contributions to the electromagnetic and weak properties of the tau lepton are calculated. It is found that such contributions can be greater than the standard model (SM) contributions, though they can be of similar order of magnitude than the contributions from other SM extensions, such as an extension of the minimal supersymmetric standard model with vectorlike multiplets. For the unparticles parameters, the most recent CMS bound from mono-jet production plus missing transverse energy at the LHC are considered.