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Related papers: $k_T$ factorization of exclusive processes

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In the $k_T$-factorization for exclusive processes, the nontrivial $k_T$-dependence of perturbative coefficients, or hard parts, is obtained by taking off-shell partons. This brings up the question of whether the $k_T$-factorization is…

High Energy Physics - Phenomenology · Physics 2009-04-06 F. Feng , J. P. Ma , Q. Wang

The k_T-factorization has been widely used for exclusive decays of B-mesons. In this factorization the pertubative coefficients are extracted from scattering of off-shell partons. Because the off-shellness of partons the extracted…

High Energy Physics - Phenomenology · Physics 2009-01-21 F. Feng , J. P. Ma , Q. Wang

We prove factorization theorem for the processes $\pi\gamma^*\to\gamma$ and $\pi\gamma^*\to\pi$ to leading twist in the covariant gauge by means of the Ward identity. Soft divergences cancel and collinear divergences are grouped into a pion…

High Energy Physics - Phenomenology · Physics 2009-10-31 Hsiang-nan Li

Exclusive processes in hard electroproduction is one of the best place for understanding the factorization properties of QCD. The HERA experiment recently provided precise data for rho electroproduction, including all spin density matrix…

High Energy Physics - Phenomenology · Physics 2014-11-20 I. V. Anikin , D. Yu. Ivanov , B. Pire , L. Szymanowski , S. Wallon

We discuss applications of the perturbative QCD approach in the exclusive non-leptonic two body B-meson decays. We briefly review its ingredients and some important theoretical issues on the factorization approaches. PQCD results are…

High Energy Physics - Phenomenology · Physics 2008-11-26 Yong-Yeon Keum

I review recent progress on exclusive $B$ meson decays made in the perturbative QCD approach, concentrating on the evolution of the $B$ meson wave function in $k_T$ factorization, radiative decays, polarizations in $VV$ modes, and new…

High Energy Physics - Phenomenology · Physics 2017-08-23 Hsiang-nan Li

We review the perturbative QCD formalism for exclusive heavy meson decays, concentrating on the three-scale factorization theorem for nonleptonic processes. The formalism is then extended to the radiative decay $B\to K^*\gamma$, which…

High Energy Physics - Phenomenology · Physics 2007-05-23 Hsiang-nan Li

We prove collinear factorization theorem for the process $\pi\gamma^*\to\pi$ at the twist-3 level in the covariant gauge by means of the Ward identity, concentrating on the two-parton case. It is shown that soft divergences cancel and…

High Energy Physics - Phenomenology · Physics 2011-09-13 Makiko Nagashima , Hsiang-nan Li

I compare collinear and $k_T$ factorization theorems in perturbative QCD, and discuss their application to exclusive $B$ meson decays. Especially, I concentrate on the recently measured time-dependent CP asymmetry of the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Hsiang-nan Li

Within the kt-factorization approach, we evaluate the impact factor of the transition gamma* -> rhoT taking into account the twist 3 contributions. We show that a gauge invariant expression is obtained with the help of QCD equations of…

High Energy Physics - Phenomenology · Physics 2009-09-23 I. V. Anikin , D. Yu. Ivanov , B. Pire , L. Szymanowski , S. Wallon

Exclusive electroproduction of vector mesons is a crucial way to probe QCD factorization properties. Such a factorization is up to now only proven, at the twist 2 level, for a longitudinaly polarized meson. It is crucial to extend our…

High Energy Physics - Phenomenology · Physics 2011-04-22 I. V. Anikin , D. Yu. Ivanov , B. Pire , L. Szymanowski , S. Wallon

Exclusive processes in hard electroproduction are one of the best place for understanding QCD in view of its factorization properties. In particular, in the limit of asymptotic gamma* p center of mass energy, they give an access to the…

High Energy Physics - Phenomenology · Physics 2010-11-19 I. V. Anikin , D. Yu. Ivanov , B. Pire , L. Szymanowski , S. Wallon

In this paper we firstly demonstrate step by step that the factorization hypothesis is valid at the next-to-leading order (NLO) for the exclusive process $\rho \gamma^{\star} \to \rho$ by employing the collinear factorization approach, and…

High Energy Physics - Phenomenology · Physics 2016-02-10 Ya-lan Zhang , Shan Cheng , Jun Hua , Zhen-jun Xiao

I review the basics of the collinear factorization theorem applied primarily to deep inelastic scattering (DIS) involving forward parton distributions (PDFs) and the extensions of this theorem for exclusive processes probing non-forward…

High Energy Physics - Phenomenology · Physics 2015-03-20 Lech Szymanowski

We calculate next-to-leading-order (NLO) corrections to exclusive processes in $k_T$ factorization theorem, taking $\pi\gamma^*\to\gamma$ as an example. Partons off-shell by $k_T^2$ are considered in both the quark diagrams from full QCD…

High Energy Physics - Phenomenology · Physics 2008-11-26 Soumitra Nandi , Hsiang-nan Li

We formulate and prove a QCD factorization theorem for hard exclusive electroproduction of mesons in QCD. The proof is valid for the leading power in Q and all logarithms. This generalizes previous work on vector meson production in the…

High Energy Physics - Phenomenology · Physics 2009-10-30 John C. Collins , Leonid Frankfurt , Mark Strikman

In this paper, we firstly varify that the factorization hypothesis is valid for the exclusive process $\rho \gamma^{\star} \to \pi$ at the next-to-leading order (NLO) with the collinear factorization approach, and then extend this proof to…

High Energy Physics - Phenomenology · Physics 2014-10-08 Shan Cheng , Zhen-Jun Xiao

The nonleptonic heavy meson decays $B\to D^{(*)}\pi(\rho), J/\psi K^{(*)}$ and $D\to K^{(*)}\pi$ are studied based on the three-scale perturbative QCD factorization theorem developed recently. In this formalism the Bauer-Stech-Wirbel…

High Energy Physics - Phenomenology · Physics 2009-10-30 Tsung-Wen Yeh , Hsiang-nan Li

We show that both the k_T- and collinear factorization for the DIS structure functions can be obtained by consecutive reductions of the Compton scattering amplitude. Each of these reductions is an approximation valid under certain…

High Energy Physics - Phenomenology · Physics 2011-11-03 B. I. Ermolaev , M. Greco , S. I. Troyan

We calculate the three-parton twist-3 contribution to the $B\to\pi$ transition form factors in the $k_T$ factorization theorem. Since different mesons are involved in the initial and final states, two(three)-parton-to-three(two)-parton…

High Energy Physics - Phenomenology · Physics 2015-06-03 Yu-Chun Chen , Hsiang-nan Li
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