NNLO corrections to B --> X_u l nu in the shape-function region
| Autoři: | Asatrian, H. M., Greub, C., Pecjak, B. D. |
|---|---|
| Zdroj: | Phys.Rev.D78:114028,2008 |
| Rok vydání: | 2008 |
| Místo uložení: | High Energy Physics - Phenomenology |
| Témata: | High Energy Physics - Phenomenology |
| Popis: | The inclusive decay B --> X_u l nu is of much interest because of its potential to constrain the CKM element |V_ub|. Experimental cuts required to suppress charm background restrict measurements of this decay to the shape-function region, where the hadronic final state carries a large energy but only a moderate invariant mass. In this kinematic region, the differential decay distributions satisfy a factorization formula of the form $H \cdot J \otimes S$, where S is the non-perturbative shape function, and the object $H \cdot J$ is a perturbatively calculable hard-scattering kernel. In this paper we present the calculation of the hard function H at next-to-next-to-leading order (NNLO) in perturbation theory. Combined with the known NNLO result for the jet function J, this completes the perturbative part of the NNLO calculation for this process. Comment: 17 pages, 1 figure |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevD.78.114028 |
| Přístupová URL adresa: | http://arxiv.org/abs/0810.0987 |
| Přírůstkové číslo: | edsarx.0810.0987 |
| Autor: | Asatrian, H. M., Greub, C., Pecjak, B. D. |
| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Phys.Rev.D78:114028,2008 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevD.78.114028 |
| Popis: | The inclusive decay B --> X_u l nu is of much interest because of its potential to constrain the CKM element |V_ub|. Experimental cuts required to suppress charm background restrict measurements of this decay to the shape-function region, where the hadronic final state carries a large energy but only a moderate invariant mass. In this kinematic region, the differential decay distributions satisfy a factorization formula of the form $H \cdot J \otimes S$, where S is the non-perturbative shape function, and the object $H \cdot J$ is a perturbatively calculable hard-scattering kernel. In this paper we present the calculation of the hard function H at next-to-next-to-leading order (NNLO) in perturbation theory. Combined with the known NNLO result for the jet function J, this completes the perturbative part of the NNLO calculation for this process. Comment: 17 pages, 1 figure |
| Databáze: | arXiv |
| Externí odkaz: |
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