Pion pair production in e{sup +}e{sup } annihilation
Abstract
We present an analysis of the process e{sup +}e{sup }{yields}{gamma}* or Z*{yields}{pi}{pi}{gamma}, in the kinematical region where {radical}(s), the c.m. energy of the e{sup +}e{sup } pair, is large but much below the Zpole. The subprocess {gamma}* or Z*{yields}{pi}{pi}{gamma} can be described by the convolution of the hard scattering coefficient {gamma}* or Z*{yields}qq{gamma} and the general distribution amplitude of two pions qq{yields}{pi}{pi}. In the case of neutral pion, the production through {gamma}* is the dominant process, which can therefore be used to access the generalized distribution amplitudes (GDAs) of the pion, especially their Ceven parts. The {gamma}Z interference term provides an alternative approach to extract the weak mixing angle sin{theta}{sub W} through measuring the helicity asymmetry in the process e{sup +}e{sup }{yields}{pi}{sup 0}{pi}{sup 0}{gamma}. In the case of charged pion pair production, the Bremsstrahlung process dominates and its interference with e{sup +}e{sup }{yields}{gamma}*{yields}{pi}{sup +}{pi}{sup }{gamma} can be applied to study the process {gamma}*{yields}{pi}{pi}{gamma} at the amplitude level.
 Authors:
 Departamento de Fisica, Universidad Tecnica Federico Santa Maria, Casilla 110V, Valparaiso (Chile)
 Publication Date:
 OSTI Identifier:
 20782996
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physical Review. D, Particles Fields; Journal Volume: 73; Journal Issue: 9; Other Information: DOI: 10.1103/PhysRevD.73.094021; (c) 2006 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; AMPLITUDES; ANNIHILATION; ASYMMETRY; BREMSSTRAHLUNG; DISTRIBUTION; ELECTRONPOSITRON INTERACTIONS; HELICITY; INCLUSIVE INTERACTIONS; INTERFERENCE; PAIR PRODUCTION; PARTICLE DECAY; PHOTONS; PHOTOPRODUCTION; PIONS MINUS; PIONS NEUTRAL; PIONS PLUS; QUARKANTIQUARK INTERACTIONS; SCATTERING; WEINBERG ANGLE; Z NEUTRAL BOSONS
Citation Formats
Lu Zhun, and Schmidt, Ivan. Pion pair production in e{sup +}e{sup } annihilation. United States: N. p., 2006.
Web. doi:10.1103/PHYSREVD.73.094021.
Lu Zhun, & Schmidt, Ivan. Pion pair production in e{sup +}e{sup } annihilation. United States. doi:10.1103/PHYSREVD.73.094021.
Lu Zhun, and Schmidt, Ivan. Mon .
"Pion pair production in e{sup +}e{sup } annihilation". United States.
doi:10.1103/PHYSREVD.73.094021.
@article{osti_20782996,
title = {Pion pair production in e{sup +}e{sup } annihilation},
author = {Lu Zhun and Schmidt, Ivan},
abstractNote = {We present an analysis of the process e{sup +}e{sup }{yields}{gamma}* or Z*{yields}{pi}{pi}{gamma}, in the kinematical region where {radical}(s), the c.m. energy of the e{sup +}e{sup } pair, is large but much below the Zpole. The subprocess {gamma}* or Z*{yields}{pi}{pi}{gamma} can be described by the convolution of the hard scattering coefficient {gamma}* or Z*{yields}qq{gamma} and the general distribution amplitude of two pions qq{yields}{pi}{pi}. In the case of neutral pion, the production through {gamma}* is the dominant process, which can therefore be used to access the generalized distribution amplitudes (GDAs) of the pion, especially their Ceven parts. The {gamma}Z interference term provides an alternative approach to extract the weak mixing angle sin{theta}{sub W} through measuring the helicity asymmetry in the process e{sup +}e{sup }{yields}{pi}{sup 0}{pi}{sup 0}{gamma}. In the case of charged pion pair production, the Bremsstrahlung process dominates and its interference with e{sup +}e{sup }{yields}{gamma}*{yields}{pi}{sup +}{pi}{sup }{gamma} can be applied to study the process {gamma}*{yields}{pi}{pi}{gamma} at the amplitude level.},
doi = {10.1103/PHYSREVD.73.094021},
journal = {Physical Review. D, Particles Fields},
number = 9,
volume = 73,
place = {United States},
year = {Mon May 01 00:00:00 EDT 2006},
month = {Mon May 01 00:00:00 EDT 2006}
}

Supersymmetric corrections to heavy quark pair production in [ital e][sup +][ital e][sup [minus]] annihilation
The supersymmetric [ital O]([alpha][ital m][sub [ital t]][sup 2]/[ital m][sub [ital W]][sup 2]) corrections to [ital t[bar t]] and [ital b[bar b]] production in [ital e][sup +][ital e][sup [minus]] annihilation are calculated in the minimal supersymmetric model. We consider the polarization of the electron beam and present the analytic expression for the renormalized differential cross section in terms of the wellknown notation of Feynman integrals. We find that the corrections to the total cross section and the leftright asymmetry can both reach a few percent for favorable parameter values, but for the forwardbackward asymmetry the correction is negligibly small ([lt]1%).