The Decay B → Sg at Nll in the Standard Model

I present the Standard Model calculation of the decay rate Γ(b → sg) (g denotes a gluon) at next-to-leading logarithms (NLL). In order to get a meaningful physical result, the decay b → sgg and certain contributions of b → sf̄f (where f are the light quark flavours u, d and s) have to be included as well. Numerically we get BNLL(b → sg) = (5.0 ± 1.0) · 10 which is more than a factor 2 larger than the leading logarithmic result BLL(b → sg) = (2.2± 0.8) · 10. Further, I consider the impact of this contribution on the charmless hadronic branching ratio Bc/, which could be used to extract the CKM-ratio |Vub/Vcb| with more accuracy. Finally, I have a short look at Bc/ in scenarios where the Wilson coefficient C8 is enhanced by new physics. Talk presented at the “UK Phenomenology Workshop on Heavy Flavour and CP Violation” St John’s College, Durham, 17 22 September 2000 The decay b → sg at NLL in the Standard Model Patrick Liniger‡ Institut für theoretische Physik, Universität Bern, CH-3012 Bern E-mail: [email protected] Abstract. I present the Standard Model calculation of the decay rate Γ(b → sg) (g denotes a gluon) at next-to-leading logarithms (NLL). In order to get a meaningful physical result, the decay b → sgg and certain contributions of b → sf̄f (where f are the light quark flavours u, d and s) have to be included as well. Numerically we get BNLL(b → sg) = (5.0±1.0) ·10−3 which is more than a factor 2 larger than the leading logarithmic result BLL(b → sg) = (2.2± 0.8) · 10. Further, I consider the impact of this contribution on the charmless hadronic branching ratio Bc/, which could be used to extract the CKM-ratio |Vub/Vcb| with more accuracy. Finally, I have a short look at Bc/ in scenarios where the Wilson coefficient C8 is enhanced by new physics. I present the Standard Model calculation of the decay rate Γ(b → sg) (g denotes a gluon) at next-to-leading logarithms (NLL). In order to get a meaningful physical result, the decay b → sgg and certain contributions of b → sf̄f (where f are the light quark flavours u, d and s) have to be included as well. Numerically we get BNLL(b → sg) = (5.0±1.0) ·10−3 which is more than a factor 2 larger than the leading logarithmic result BLL(b → sg) = (2.2± 0.8) · 10. Further, I consider the impact of this contribution on the charmless hadronic branching ratio Bc/, which could be used to extract the CKM-ratio |Vub/Vcb| with more accuracy. Finally, I have a short look at Bc/ in scenarios where the Wilson coefficient C8 is enhanced by new physics.