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Title: Exclusive processes e{sup +}e{sup -}{yields}VP in k{sub T} factorization

Abstract

The exclusive processes e{sup +}e{sup -}{yields}VP, in the region of which the final state meson momentum is much larger than the hadronic scale {lambda}{sub QCD}, are studied in the framework of the perturbative quantum chromodynamics (PQCD) approach based on the k{sub T} factorization. Including the transverse momentum distribution in the light-cone wave functions, our results are consistent with the experimental measurements. According to our results, many processes have large enough cross sections to be detected at {radical}(s)=10.58 GeV. The s dependence of the cross section has been directly studied and our result indicates that the 1/s{sup 3} scaling is more favored than 1/s{sup 4}. We also find that the gluonic contribution for the processes involving {eta}{sup (')} is tiny.

Authors:
 [1];  [2]; ;  [3]
  1. CCAST (World Laboratory), P.O. Box 8730, Beijing 100080 (China)
  2. (4), 100049 (China)
  3. Institute of High Energy Physics, CAS, P.O. Box 918(4), 100049 (China)
Publication Date:
OSTI Identifier:
21020492
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 9; Other Information: DOI: 10.1103/PhysRevD.75.094020; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CROSS SECTIONS; DISTRIBUTION; ELECTRON-POSITRON INTERACTIONS; ELECTRONS; ETA PRIME-958 MESONS; EXCLUSIVE INTERACTIONS; FACTORIZATION; GEV RANGE; LIGHT CONE; PERTURBATION THEORY; POSITRONS; QUANTUM CHROMODYNAMICS; TRANSVERSE MOMENTUM; VECTOR MESONS; WAVE FUNCTIONS

Citation Formats

Lue Caidian, Institute of High Energy Physics, CAS, P.O. Box 918, Wang Wei, and Wang Yuming. Exclusive processes e{sup +}e{sup -}{yields}VP in k{sub T} factorization. United States: N. p., 2007. Web. doi:10.1103/PHYSREVD.75.094020.
Lue Caidian, Institute of High Energy Physics, CAS, P.O. Box 918, Wang Wei, & Wang Yuming. Exclusive processes e{sup +}e{sup -}{yields}VP in k{sub T} factorization. United States. doi:10.1103/PHYSREVD.75.094020.
Lue Caidian, Institute of High Energy Physics, CAS, P.O. Box 918, Wang Wei, and Wang Yuming. Tue . "Exclusive processes e{sup +}e{sup -}{yields}VP in k{sub T} factorization". United States. doi:10.1103/PHYSREVD.75.094020.
@article{osti_21020492,
title = {Exclusive processes e{sup +}e{sup -}{yields}VP in k{sub T} factorization},
author = {Lue Caidian and Institute of High Energy Physics, CAS, P.O. Box 918 and Wang Wei and Wang Yuming},
abstractNote = {The exclusive processes e{sup +}e{sup -}{yields}VP, in the region of which the final state meson momentum is much larger than the hadronic scale {lambda}{sub QCD}, are studied in the framework of the perturbative quantum chromodynamics (PQCD) approach based on the k{sub T} factorization. Including the transverse momentum distribution in the light-cone wave functions, our results are consistent with the experimental measurements. According to our results, many processes have large enough cross sections to be detected at {radical}(s)=10.58 GeV. The s dependence of the cross section has been directly studied and our result indicates that the 1/s{sup 3} scaling is more favored than 1/s{sup 4}. We also find that the gluonic contribution for the processes involving {eta}{sup (')} is tiny.},
doi = {10.1103/PHYSREVD.75.094020},
journal = {Physical Review. D, Particles Fields},
number = 9,
volume = 75,
place = {United States},
year = {Tue May 01 00:00:00 EDT 2007},
month = {Tue May 01 00:00:00 EDT 2007}
}
  • This paper is devoted to consideration of the hard exclusive processes e{sup +}e{sup -}{yields}VP, where V={rho}, {phi}; P={eta}, {eta}{sup '}. Experimental measurement of the cross section of the process e{sup +}e{sup -}{yields}{phi}{eta} at the BABAR Collaboration at large center of mass energy {radical}(s)=10.6 GeV and some low energy experimental data {radical}(s){approx}2-4 GeV give us the possibility to study the cross section in the broad energy region. As a result, we have determined the asymptotic behavior of the cross section of e{sup +}e{sup -}{yields}{phi}{eta} in the limit s{yields}{infinity}, which is in agreement with perturbative QCD prediction. Assuming that the same asymptoticmore » behavior is valid for the other processes under consideration and using low energy experimental data, we have predicted the cross sections of these processes at energies {radical}(s)=3.67, 10.6 GeV. In addition, we have calculated the cross sections of these processes at the same energies within perturbative QCD. Our results are in agreement with available experimental data.« less
  • By using 1.8x10{sup 6} DD pairs, we have measured B(D{sup 0}{yields}{pi}{sup -}e{sup +}{nu}{sub e})=0.299(11)(9)%, B(D{sup +}{yields}{pi}{sup 0}e{sup +}{nu}{sub e})=0.373(22)(13)%, B(D{sup 0}{yields}K{sup -}e{sup +}{nu}{sub e})=3.56(3)(9)%, and B(D{sup +}{yields}K{sup 0}e{sup +}{nu}{sub e})=8.53(13)(23)% and have studied the q{sup 2} dependence of the form factors. By combining our results with recent lattice calculations, we obtain |V{sub cd}|=0.217(9)(4)(23) and |V{sub cs}|=1.015(10)(11)(106)
  • Using a sample of 1.8 million DD mesons collected at the {psi}(3770) with the CLEO-c detector, we study the semileptonic decays D{sup 0}{yields}{pi}{sup -}e{sup +}{nu}{sub e}, D{sup +}{yields}{pi}{sup 0}e{sup +}{nu}{sub e}, D{sup 0}{yields}K{sup -}e{sup +}{nu}{sub e}, and D{sup +}{yields}K{sup 0}e{sup +}{nu}{sub e}. For the total branching fractions we find B(D{sup 0}{yields}{pi}{sup -}e{sup +}{nu}{sub e})=0.299(11)(9)%, B(D{sup +}{yields}{pi}{sup 0}e{sup +}{nu}{sub e})=0.373(22)(13)%, B(D{sup 0}{yields}K{sup -}e{sup +}{nu}{sub e})=3.56(3)(9)%, and B(D{sup +}{yields}K{sup 0}e{sup +}{nu}{sub e})=8.53(13)(23)%, where the first error is statistical and the second systematic. In addition, form factors are studied through fits to the partial branching fractions obtained in five q{sup 2} ranges. Bymore » combining our results with recent unquenched lattice calculations, we obtain |V{sub cd}|=0.217(9)(4)(23) and |V{sub cs}|=1.015(10)(11)(106), where the final error is theoretical.« less
  • Using {psi}(3770){yields}DD events collected with the CLEO-c detector at the Cornell e{sup +}e{sup -} storage ring, tagged by fully reconstructing one D meson in a hadronic decay mode, we measure absolute branching fractions and differential decay rates for D{sup 0}{yields}{pi}{sup -}e{sup +}{nu}{sub e}, D{sup +}{yields}{pi}{sup 0}e{sup +}{nu}{sub e}, D{sup 0}{yields}K{sup -}e{sup +}{nu}{sub e}, and D{sup +}{yields}K{sup 0}e{sup +}{nu}{sub e}. The measured decay rates are used to study semileptonic form factors governing these transitions and to test unquenched Lattice QCD (LQCD) calculations. We average our results with previously published CLEO-c measurements of the same quantities using a neutrino reconstruction technique. Combiningmore » LQCD calculations of form factor absolute normalizations f{sub +}(0) and measurements of f{sub +}{sup {pi}}(0)|V{sub cd}| and f{sub +}{sup K}(0)|V{sub cs}|, we find |V{sub cd}|=0.222(8)(3)(23) and |V{sub cs}|=1.018(10)(8)(106), where the uncertainties are statistical, experimental systematic, and from LQCD, respectively.« less
  • We calculate next-to-leading-order corrections to exclusive processes in the k{sub T} factorization theorem, taking {pi}{gamma}*{yields}{gamma} as an example. Partons off shell by k{sub T}{sup 2} are considered in both the quark diagrams from full QCD and the effective diagrams for the pion wave function. The gauge dependences in the above two sets of diagrams cancel, when deriving the k{sub T}-dependent hard kernel as their difference. The gauge invariance of the hard kernel is then proven to all orders by induction. The light-cone singularities in the k{sub T}-dependent pion wave function are regularized by rotating the Wilson lines away from themore » light cone. This regularization introduces a factorization-scheme dependence into the hard kernel, which can be minimized in the standard way. Both the large double logarithms ln{sup 2}k{sub T} and ln{sup 2}x, x being a parton momentum fraction, arise from the loop correction to the virtual photon vertex, the former being absorbed into the pion wave function and organized by the k{sub T} resummation and the latter absorbed into a jet function and organized by the threshold resummation. The next-to-leading-order corrections are found to be only a few percent for {pi}{gamma}*{yields}{gamma}, if setting the factorization scale to the momentum transfer from the virtual photon.« less