Study of rho0 Production in gamma d, gamma p and gamma n Reactions at 7.5-GeV/c Using Linearly Polarized Photon Beam

Alexander, G. ; Gandsman, J. ; Levy, A. ; et al.
Nucl.Phys.B 69 (1974) 445-453, 1974.
Inspire Record 94508 DOI 10.17182/hepdata.32344

The reaction γ d→d ππ , γ p→p ππ and γ n→n ππ were studied in the SLAC 82″ deuterium filled bubble chamber, exposed to a linearly polarized photon beam of 7.5 GeV. All three reactions are dominated by ϱ 0 production. The differential cross section has a slope of ∼6.5 GeV −2 for nucleon reactions and a slope of ∼27 GeV −2 for coherent deuteron reactions. The behaviour of the density matrix elements shows that ϱ production conserves s -channel c.m.s. helicity and is dominated by natural parity exchange.

1 data table

No description provided.


Measurement of the gamma-V Coupling Constants and sigma-T (Vd) from Coherent gamma-d Interactions at 7.5-GeV

Alexander, G. ; Benary, O. ; Gandsman, J. ; et al.
Phys.Lett.B 57 (1975) 487-490, 1975.
Inspire Record 2480 DOI 10.17182/hepdata.27813

We have measured the total and differential cross-sections for coherently photoproduced ϱ, ω and ϱ′ on deuterium at 7.5 GeV. Using VDM relations, we have obtained γ ω 2 / γ ϱ 2 = 7.1 ± 1.5, σ T ( ϱ d) = (54 ± 2) mb and σ T ( ω d) = (56 ± 5) mb. Assuming the amplitude for ϱ′ production via an intermediate ϱ 0 to be small and that the amplitudes for ϱp and ϱ′p elastic scattering are comparable, we found γ ϱ ′ 2 / γ ϱ 2 = 6.0 ± 1.2 and σ T ( ϱ ′d) = (47 ± 6) mb.

2 data tables

No description provided.

FROM AN EXPONENTIAL FIT WITH DEUTERON FORM FACTOR.


A Comparative Study of rho0 Photoproduced on D, N and P at 7.5-GeV

Alexander, G. ; Benary, O. ; Gandsman, J. ; et al.
Nucl.Phys.B 104 (1976) 397-412, 1976.
Inspire Record 2982 DOI 10.17182/hepdata.35986

A 7.5 GeV linearly polarized photon beam was used to study ϱ 0 production on d, n and p in the SLAC 82 inch bubble chamber. The production of ϱ 0 is found to proceed mainly via t -channel natural parity exchange and to conserve s -channel c.m.s. helicity for small t . The I = 1 contribution to the γ N → ϱ 0 t -channel amplitude is found to be small at 7.5 GeV.

6 data tables

ERRORS QUOTED INCLUDE BOTH STATISTICAL AND SYSTEMATIC UNCERTAINTIES.

THE FOURTH REACTION IS THE SUM OF THE FIRST THREE, NAMELY THE CLOSURE DIFFERENTIAL CROSS SECTION.

DIPION EVENTS IN THE RHO0 MASS REGION (600 TO 880 MEV).

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Coherent Photoproduction of Vector Mesons on Deuterium at 5.5-GeV

Gupta, Virendra Prakash ; Fung, S.Y. ; Oh, Y.T. ; et al.
Phys.Rev.D 14 (1976) 42-54, 1976.
Inspire Record 115714 DOI 10.17182/hepdata.24672

Coherent photoproduction of vector mesons ρ0, ω, φ, and ρ′ on deuterium was studied using the SLAC 82-in. bubble chamber exposed to linearly polarized photons at 5.5 GeV. The reaction channel γd→π+π−d was studied in detail. Nine independent density-matrix parameters have been determined from the ρ0 decay distribution. ρ production in this channel was found to proceed almost completely through natural-parity exchange for |t|≤0.25 GeV2 and conserve s-channel c.m. helicity for |t|≤0.15 GeV2. A measurement of differential cross section for this channel has been made.

3 data tables

POLARIZED PHOTON - VECTOR MESON DENSITY MATRICES ARE EXPLAINED BY SCHILLING/SEYBOTH/WOLF NP B15, 397 (1970). 'SH' - HELICITY FRAME..............Z = 3,RF = 1-2. 'TH' - GOTTFRIED-JACKSON FRAME.....Z = 1,RF = 3. 'ADAIR' - ADAIR FRAME..............Z = 1,RF = 1-2.

No description provided.

ERROR INCLUDES BACKGROUND UNCERTAINTY.