Dresden 2000 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

HK: Physik der Hadronen und Kerne

HK 2: Theorie I

HK 2.3: Vortrag

Montag, 20. März 2000, 14:45–15:00, B 81

Dispersionsrelationen bei festem t und Q2 für virtuelle Comptonstreuung am Nukleon — •M. Gorchtein1, D. Drechsel1, A. Metz2, B. Pasquini1 und M. Vanderhaeghen11Institut für Kernphysik, Johannes Gutenberg Universität Mainz, Germany — 2CEA-Saclay, DAPNIA/SPhN, F-91191 Gif-sur-Yvette, France

Dispersion relations at fixed t and Q2 are presented for virtual Compton scattering (VCS) off the nucleon at outgoing photon energies ≤ 500 MeV and low Q2 (up to 1 GeV2), as a formalism to extract the generalized nucleon polarizabilities [1,2,3]. We extend the dispersion theory developed in [4] for real Compton scattering to the case of a virtual initial photon. Dispersion integrals for VCS are mainly saturated by π N intermediate states in the s-channel, γ* N → π N → γ N, and two pion intermediate states in the t-channel, γ*γ →  ππ → NN. Present results are compared to recent MAMI data, and the importance of double polarization observables for measuring the generalized polarizabilities is displayed.

[1] P.A.M. Guichon et al., Nucl. Phys. A 591 (1995) 606

[2] P.A.M. Guichon and M. Vanderhaeghen, Prog. Part. Nucl. Phys. 51 (1998) 125

[3] D.Drechsel, G. Knöchlein, A. Metz and S. Scherer, Phys. Rev. C55 (1997) 424

[4] D. Drechsel, M. Gorchtein, B. Pasquini and M. Vanderhaeghen, Phys. Rev. C (2000) in press; hep-ph/9904290

100% | Mobil-Ansicht | English Version | Kontakt/Impressum/Datenschutz
DPG-Physik > DPG-Verhandlungen > 2000 > Dresden