Pion pair production in e{sup +}e{sup -} annihilation

Journal Article · Mon May 01 00:00:00 EDT 2006 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.73.094021· OSTI ID:20782996

Zhun, Lu; Schmidt, Ivan ^[1]

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1. Departamento de Fisica, Universidad Tecnica Federico Santa Maria, Casilla 110-V, Valparaiso (Chile)

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 Z-pole. 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 C-even 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.

• OSTI ID: 20782996
• Journal Information: Physical Review. D, Particles Fields, Vol. 73, Issue 9; Other Information: DOI: 10.1103/PhysRevD.73.094021; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
ANNIHILATION
ASYMMETRY
BREMSSTRAHLUNG
DISTRIBUTION
ELECTRON-POSITRON INTERACTIONS
HELICITY
INCLUSIVE INTERACTIONS
INTERFERENCE
PAIR PRODUCTION
PARTICLE DECAY
PHOTONS
PHOTOPRODUCTION
PIONS MINUS
PIONS NEUTRAL
PIONS PLUS
QUARK-ANTIQUARK INTERACTIONS
SCATTERING
WEINBERG ANGLE
Z NEUTRAL BOSONS