✦ LIBER ✦
Partonic structure of π and ρ mesons from data on hard exclusive production of two pions off nucleon
✍ Scribed by B. Clerbaux; M.V. Polyakov
- Publisher
- Elsevier Science
- Year
- 2000
- Tongue
- English
- Weight
- 129 KB
- Volume
- 679
- Category
- Article
- ISSN
- 0375-9474
No coin nor oath required. For personal study only.
✦ Synopsis
We fitted the ππ mass distribution in the range 0.5 M ππ 1.1 GeV measured in hard exclusive positron-proton reactions at HERA by the form dictated by QCD at leading-twist level. Extracted parameters are related to valence-quark distribution in the pion, and to the pion and ρ meson distribution amplitudes. We obtain, for the first time, a measurement of the second Gegenbauer coefficient of the ρ meson distribution amplitude: a (ρ) 2 = -0.10 ± 0.20 for a photon virtuality of Q 2 = 21.2 GeV 2 .