CLAS Physics Database

g7a: Search for medium modification of light vector mesons off nuclei

Spokespersons
D. Weygand, C. Djalali, M. Kossov
Year
2007
Abstract
Data were taken with a beam of tagged photons with energies up to 4 GeV on various nuclear targets. The properties of the ρ vector mesons were investigated via their rare leptonic decay to e+e. This decay channel is preferred over hadronic modes in order to eliminate final state interactions in the nuclear matter. The combinatorial background in the mass spectrum was removed by a self-normalizing mixed-event technique. The ρ mass distributions were extracted for each of the targets.
Publication
  1. R. Nasseripour, M. Wood, C. Djalali, D. Weygand, C. Tur, U. Mosel, P. Muehlich Search for Medium Modifications of the ρ Meson // Phys. Rev. Lett. 99, 262302 (2007)
Quantities
dY/dM(e+, e) dY/dMρ(e+, e)

Measurements

ID Quantity Beam Target Final state Q2min,
GeV2
Q2max,
GeV2
Wmin,
GeV
Wmax,
GeV
E103M1 dY/dM(e+, e) γ d ρ + X 0.0 0.0 None None
E103M2 dY/dM(e+, e) γ 12C ρ + X 0.0 0.0 None None
E103M3 dY/dM(e+, e) γ 56Fe ρ + X 0.0 0.0 None None
E103M4 dY/dMρ(e+, e) γ d ρ + X 0.0 0.0 None None
E103M5 dY/dMρ(e+, e) γ 12C ρ + X 0.0 0.0 None None
E103M6 dY/dMρ(e+, e) γ 56Fe ρ + X 0.0 0.0 None None