Timelike Virtual Compton Scattering from Electron-Positron Radiative Annihilation

Journal Article · Thu Jan 01 04:00:00 EST 2009 · Preprint to be distributed

OSTI ID:956327

Afanaciev, Andrei; Afanasev, Andrei; Afanaciev, Andrei; Afanasev, Andrei; J Brodsky, Stanley; E Carlson, Carl; Mukherjee, Asmita

We propose measurements of the deeply virtual Compton amplitude (DVCS), gamma* to H H-bar gamma, in the timelike t = (p_{H} + p_{H-bar})^2 > 0 kinematic domain which is accessible at electron-positron colliders via the radiative annihilation process e+ e- to H H-bar gamma. These processes allow the measurement of timelike deeply virtual Compton scattering for a variety of H H-bar hadron pairs such as pi+ pi-, K+ K-, and D D-bar as well as p p-bar. As in the conventional spacelike DVCS, there are interfering coherent amplitudes contributing to the timelike processes involving C= - form factors. The interference between the amplitudes measures the phase of the C=+ timelike DVCS amplitude relative to the phase of the timelike form factors and can be isolated by considering the forward-backward e+ \leftrightarrow e- asymmetry. The J=0 fixed pole contribution which arises from the local coupling of the two photons to the quark current plays a special role. As an example we present a simple

• Research Organization: Thomas Jefferson Lab National Accelerator Facility
• Sponsoring Organization: USDOE
• OSTI ID: 956327
• Report Number(s): JLAB-THY-09-962; arxiv:0903.4188; DOE/OR/23177-0659
• Journal Information: Preprint to be distributed, Journal Name: Preprint to be distributed
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
AMPLITUDES
ANNIHILATION
ASYMMETRY
COMPTON EFFECT
FORM FACTORS
HADRONS
PHOTONS
QUARKS