Observation of a Coherence Length Effect in Exclusive {rho}{sup 0} Electroproduction
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada)
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439-4843 (United States)
- W. K. Kellogg Radiation Lab, California Institute of Technology, Pasadena, California 91125 (United States)
- Nuclear Physics Laboratory, University of Colorado, Boulder, Colorado 80309-0446 (United States)
- DESY, Deutsches Elektronen Synchrotron, D-22603 Hamburg (Germany)
- DESY Zeuthen, D-15738 Zeuthen (Germany)
- Joint Institute for Nuclear Research, 141980 Dubna (Russia)
- Physikalisches Institut, Universitaet Erlangen-Nuernberg, D-91058 Erlangen (Germany)
- Dipartimento di Fisica, Universita di Ferrara, I-44100 Ferrara (Italy)
Exclusive incoherent electroproduction of the {rho}{sup 0}{number_sign}770 meson from {sup 1}H , {number_sign}{sup 2}H , {number_sign}{sup 3}He , and {number_sign}{sup 14}N targets has been studied by the HERMES experiment at squared four-momentum transfer Q{sup 2}{gt}0.4 GeV{sup 2} and positron energy loss {nu} from 9 to 20 GeV. The ratio of the {number_sign}{sup 14}N to {number_sign}{sup 1}H cross sections per nucleon, known as the nuclear transparency, was found to decrease with increasing coherence length of quark-antiquark fluctuations of the virtual photon. The data provide clear evidence of the interaction of the quark-antiquark fluctuations with the nuclear medium. {copyright} {ital 1999} {ital The American Physical Society}
- OSTI ID:
- 347062
- Journal Information:
- Physical Review Letters, Vol. 82, Issue 15; Other Information: PBD: Apr 1999
- Country of Publication:
- United States
- Language:
- English
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