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Heavy quark distribution function in QCD and the $AC^{2}M^{2}$ model
We show that the phenomenological \ACM ansatz is consistent with QCD through order $1/m_b$ in the description of $B\ra l\bar \nu_l+X_u$ and $B\ra \gamma +X_s$ transitions, including their energy spectra and differential distributions. This suggests a concrete realization for the QCD distribution fun...
| Autores principales: | , , , |
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| Lenguaje: | eng |
| Publicado: |
1994
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| Materias: | |
| Acceso en línea: | https://dx.doi.org/10.1016/0370-2693(94)91502-4 http://cds.cern.ch/record/258469 |
| _version_ | 1780885970531385344 |
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| author | Bigi, Ikaros I.Y. Shifman, Mikhail A. Uraltsev, N. Vainshtein, Arkady I. |
| author_facet | Bigi, Ikaros I.Y. Shifman, Mikhail A. Uraltsev, N. Vainshtein, Arkady I. |
| author_sort | Bigi, Ikaros I.Y. |
| collection | CERN |
| description | We show that the phenomenological \ACM ansatz is consistent with QCD through order $1/m_b$ in the description of $B\ra l\bar \nu_l+X_u$ and $B\ra \gamma +X_s$ transitions, including their energy spectra and differential distributions. This suggests a concrete realization for the QCD distribution function, the "Roman" function. On the other hand the endpoint description does not hold for $B\ra l\bar \nu_l+X_c$ decays. The intrinsic limitation of the \ACM model could reveal itself in different values of the effective $b$ quark mass from fits of semileptonic $\Lambda _b$ and $B$ decays. |
| id | cern-258469 |
| institution | Organización Europea para la Investigación Nuclear |
| language | eng |
| publishDate | 1994 |
| record_format | invenio |
| spelling | cern-2584692023-03-14T18:53:26Zdoi:10.1016/0370-2693(94)91502-4http://cds.cern.ch/record/258469engBigi, Ikaros I.Y.Shifman, Mikhail A.Uraltsev, N.Vainshtein, Arkady I.Heavy quark distribution function in QCD and the $AC^{2}M^{2}$ modelParticle Physics - TheoryWe show that the phenomenological \ACM ansatz is consistent with QCD through order $1/m_b$ in the description of $B\ra l\bar \nu_l+X_u$ and $B\ra \gamma +X_s$ transitions, including their energy spectra and differential distributions. This suggests a concrete realization for the QCD distribution function, the "Roman" function. On the other hand the endpoint description does not hold for $B\ra l\bar \nu_l+X_c$ decays. The intrinsic limitation of the \ACM model could reveal itself in different values of the effective $b$ quark mass from fits of semileptonic $\Lambda _b$ and $B$ decays.We show that the phenomenological \ACM ansatz is consistent with QCD through order $1/m_b$ in the description of $B\ra l\bar \nu_l+X_u$ and $B\ra \gamma +X_s$ transitions, including their energy spectra and differential distributions. This suggests a concrete realization for the QCD distribution function, which we call the ``Roman'' function. On the other hand the \ACM model description of the end-point domain in $B\ra l\bar \nu_l + X_c$ is incompatible with QCD: a different distribution function enters the description of $b\ra c$ decays as compared to the transitions to the massless quarks. Both observations -- the validity of the {\ACM}-like description for heavy-to-light transitions and the emergence of the new distribution function in the $b\ra c$ case -- are in contradiction to a recent claim in the literature. The intrinsic limitation of the \ACM model could reveal itself in different values of the effective $b$ quark mass from fits of the $\Lambda _b$ and $B$ decays.We show the phenomenological AC 2 M 2 ansatz to be consistent with QCD through order 1/ m b in the description of B → l v l + X u and B → γ + X s transitions, including their energy spectra and differential distributions. This suggests a concrete realization of the QCD distribution function, which we call the “Roman” function. Yet the AC 2 M 2 description of the end-point domain in B → l v l + X c is, formally speaking, incompatible with QCD: a different distribution function enters the description of b → c decays as compared to the transitions to massless quarks. The intrinsic limitation of the AC 2 M 2 model could reveal itself in different values of the effective b quark mass from fits of the Λ b and B decays.hep-ph/9402225TPI-MINN-94-2-TUMN-TH-1235-94UND-HEP-94-BIG02CERN-TH-7159-94CERN-TH-7159-94TPI-MINN-94-002-TUMN-TH-1235UND-HEP-94-BIG-02oai:cds.cern.ch:2584691994 |
| spellingShingle | Particle Physics - Theory Bigi, Ikaros I.Y. Shifman, Mikhail A. Uraltsev, N. Vainshtein, Arkady I. Heavy quark distribution function in QCD and the $AC^{2}M^{2}$ model |
| title | Heavy quark distribution function in QCD and the $AC^{2}M^{2}$ model |
| title_full | Heavy quark distribution function in QCD and the $AC^{2}M^{2}$ model |
| title_fullStr | Heavy quark distribution function in QCD and the $AC^{2}M^{2}$ model |
| title_full_unstemmed | Heavy quark distribution function in QCD and the $AC^{2}M^{2}$ model |
| title_short | Heavy quark distribution function in QCD and the $AC^{2}M^{2}$ model |
| title_sort | heavy quark distribution function in qcd and the $ac^{2}m^{2}$ model |
| topic | Particle Physics - Theory |
| url | https://dx.doi.org/10.1016/0370-2693(94)91502-4 http://cds.cern.ch/record/258469 |
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