Unparticle contributions to $\Bs$-$\Bsbar$ mixing

Abstract

The unparticle effects on the $\Bs$-$\Bsbar$ mixing is revisited. Taking into account the unitarity constraints on the unparticle operators, we find that the contribution of the vector unparticle is very suppressed compared to that of the scalar unparticle. This is due to the fact that the lower bound of the scaling dimension of the vector-unparticle operator is larger. It is also shown that the mixing phase from the scalar unparticle is negative, and unparticles can produce large mixing phase.