Jun 13 – 17, 2011
Europe/Berlin timezone
Proceedings are now available online at <a href="http://www.slac.stanford.edu/econf/C110613/">eConf</a>

Study of interference of Coulomb and strong diffractive production of pi-pi-pi+ systems produced off Pb target at COMPASS

Jun 17, 2011, 10:25 AM
Club 1 (Künstlerhaus)

Club 1


talk Low-Energy Processes Low-Energy Processes


Dr Dmitry Ryabchikov (Institute for High Energy Physics)


The reaction pi-Pb->pi-pi-pi+Pb with E_beam = 190 GeV is studied in great detail by Partial-Wave analysis methods. The low momentum transfer region t' < 0.01 GeV/c^2 shows the dominance of coherent diffraction production mechanism and also clear contribution of Coulomb production. For several M=1 amplitudes the intensities as functions of t' demonstrate very sharp peaks near zero, characteristic for photon exchange, while phase motions as functions of t' show significant variation which reflects the interference of Coulomb and strong processes. Theoretical description of measured intensities and phases can provide precise separation of Coulomb contribution (and thus give better measurement of a2(1320) radiative width as an example) as well as better knowledge of absolute phase of strong diffractive amplitude (and so properties of the pomeron regge trajectory).

Primary author

Dr Dmitry Ryabchikov (Institute for High Energy Physics)

Presentation materials