High energy photoproduction of the rho and rho' vector mesons. [R]

Technical Report · Sat Jan 01 04:00:00 EST 1977

DOI:https://doi.org/10.2172/6161250· OSTI ID:6161250

Bronstein, J. M.

In an experiment in the broad band photon beam at Fermilab diffractive production of 2..pi../sup + -/ and 4..pi../sup + -/ states from Be, Al, Cu, and Pb targets was observed. The 2..pi.. data is dominated by the rho(770) and the 4..pi../sup + -/ is dominated by the rho'(1500). The energy dependence of rho photoproduction from Be was measured, and no evidence seen for energy variation of the forward cross section in the range 30 to 160 GeV. The forward cross section is consistent with its average value dsigma/dt//sup 0/ = 3.42 +- 0.28 ..mu..b/GeV/sup 2/ over the entire range. For the rho' a mass of 1487 +- 20 MeV and a width of 675 +- 60 MeV were obtained. All quoted errors are statistical. A standard optical model analysis of the A dependence of the rho and rho' photoproduction yields the following results. f/sub rho'//sup 2//f/sub rho//sup 2/ = 3.7 +- 7; sigma/sub rho'//sigma/sub rho/ = 1.05 +- 0.18. Results for the photon coupling constants are in good agreement with GVMD and the e/sup +/e- storage ring results. The approximate equality of the rho--nucleon and rho'--nucleon total cross sections is inconsistent with the diagonal version of GVMD and provides strong motivation for including transitions between different vector mesons in GVMD. 50 references.

• Research Organization: Illinois Univ., Urbana (USA). Graduate Coll.
• DOE Contract Number: EY-76-C-02-1195
• OSTI ID: 6161250
• Report Number(s): COO-1195-412
• Country of Publication: United States
• Language: English

Related Subjects

645101* -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Electromagnetic Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ALKALINE EARTH METALS
ALUMINIUM
BERYLLIUM
BOSONS
COPPER
COUPLING CONSTANTS
CROSS SECTIONS
DECAY
ELEMENTARY PARTICLES
ELEMENTS
ENERGY DEPENDENCE
HADRONIC PARTICLE DECAY
HADRONS
LEAD
MASS
MASSLESS PARTICLES
MESON RESONANCES
MESONS
METALS
NUCLEAR REACTIONS
PARTICLE DECAY
PARTICLE PROPERTIES
PARTICLE WIDTHS
PHOTONS
PHOTONUCLEAR REACTIONS
RESONANCE PARTICLES
RHO-1500 RESONANCES
RHO-765 RESONANCES
TOTAL CROSS SECTIONS
TRANSITION ELEMENTS
VECTOR MESONS