B̄ → X s γ after Completion of the NLO QCD Calculations Andrzej
نویسنده
چکیده
Several years ago, Stefan Pokorski, Manfred Münz and us outlined a program for calculation of the NLO QCD corrections to the weak radiative B̄ meson decay B̄ → Xsγ. Very recently, just before the 60th birthday of Stefan Pokorski, this program has been formally completed. In the present paper, we summarize the existing results and discuss perspectives for further improvement of the accuracy of the Standard Model prediction for BR[B̄ → Xsγ]. Submitted to the special issue of Acta Physica Polonica B dedicated to Stefan Pokorski on the occasion of his 60th birthday.
منابع مشابه
Completing the NLO QCD calculation of B̄ → X s γ
We evaluate two-loop b → sγ matrix elements of all the four-quark operators containing no derivatives. Contrary to previous calculations, no expansion in the mass ratio mc/mb is performed, and all the possible Dirac and flavor structures are included. Consequently, we are able to provide the last item in the NLO analysis of B̄ → Xsγ that has been missing so far, namely the two-loop matrix elemen...
متن کامل8 v 2 2 8 Ja n 20 04 Rare decays B̄ → X s ( d ) γ at the NLO
We present an independent calculation of O(αs) matrix elements of the QCD penguin operators for the decays B̄ → Xs(d)γ. The Mellin-Barnes representation technique is applied for the systematic numerical evaluation of involved two-loop diagrams. The numerical effect of the calculated contributions is confirmed to be of order of 1%. We also present an updated numerical analysis for B̄ → Xs(d)γ deca...
متن کاملRare decays B̄ → X s ( d ) γ at the NLO
We present an independent calculation of O(αs) matrix elements of the QCD penguin operators for the decays B̄ → Xs(d)γ. The Mellin-Barnes representation technique is applied for the systematic numerical evaluation of involved two-loop diagrams. The numerical effect of the calculated contributions is confirmed to be of order of 1%. We also present an updated numerical analysis for B̄ → Xs(d)γ deca...
متن کاملJet Cross Sections at HERA - Current Issues
Since the start of HERA operation there has been considerable progress in the understanding of jet production in ep collisions. QCD calculations are now able to accommodate the hadronic structure of the virtual photon. The luminosities delivered by HERA are now sufficient to allow studies of final states in which more than two high transverse energy jets are produced. The transition between jet...
متن کاملComplete ( O 7 , O 8 ) contribution to B̄ → X s γ at O ( α 2 s )
We calculate the set of O(αs) corrections to the branching ratio and to the photon energy spectrum of the decay process B̄ → Xsγ originating from the interference of diagrams involving the electromagnetic dipole operator O7 with diagrams involving the chromomagnetic dipole operator O8. The corrections evaluated here are one of the elements needed to complete the calculations of the B̄ → Xsγ branc...
متن کامل