Inelastic rho/sup 0/ electroproduction

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1980

OSTI ID:5506488

Cohen, I M

The apparatus consisted of a streamer chamber with an internal hydrogen target and associated triggering devices. The experiment was performed with an 11.5 GeV electron beam extracted from the synchrotron at the Wilson Synchrotron Laboratory. THe kinematic region 1 < Q/sup 2/ < 6 GeV/sup 2/, 2.8 < W < 4.2 GeV and x > 0.1 was used in the analysis, with = 2.5 GeV/sup 2/, = 3.3 GeV, and = 0.20. The sample contained 17420 events. For the inelastic rho/sup 0/ electroproduction, the z dependence of the cross section, the p/sub t//sup 2/ dependence of the cross section, and a measure of the polarization, the density matrix element rho/sub 00/ are presented. The ratio of inelastic rho/sup 0/ electroproduction to inclusive ..pi../sup 0/ electroproduction is found to be 2.0 +- 0.5 after a correction for ..pi../sup 0/ production by rho/sup + -/ decay. The z distribution is compared with predictions of models of quark production and fragmentation, and with other experimental results thought to be described by these models. Good agreement between the experimental results is observed, which lends support to the general features of the quark-parton models. The p/sub t//sup 2/ distribution observed is reminiscent of the falling exponential seen in other inclusive channels. The mean value of p/sub t/ is found to be

= 0.52 +- 0.03 GeV. The value of rho/sub 00/ is observed to be 0.41 +- 0.08. This is slightly greater than the value 1/3, which is the value one would find if no polarization existed. This suggests a slight excess of helicity zero rho/sup 0/ mesons. The ratio of rho/sup 0/ production to ..pi../sup 0/ production is found to be 2.0 +- .05. The value suggested by spin state counting is 3. Combining the rho/sup 0/ to ..pi../sup 0/ production ratio with the measurement of rho/sub 00/, one finds that the ratio of helicity zero rho/sup 0/ meson production to ..pi../sup 0/ meson production is 0.82 +- 0.26, which is consistent with unity.

• Research Organization: Cornell Univ., Ithaca, NY (USA)
• OSTI ID: 5506488
• Country of Publication: United States
• Language: English

Related Subjects

645101* -- High Energy Physics-- Particle Interactions &amp; Properties-Experimental-- Electromagnetic Interactions &amp; Properties
645202 -- High Energy Physics-- Particle Interactions &amp; Properties-Theoretical-- Electromagnetic Interactions &amp; Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ACCELERATORS
BASIC INTERACTIONS
BOSONS
COMPOSITE MODELS
CORNELL 10-GEV SYNCHROTRON
CROSS SECTIONS
CYCLIC ACCELERATORS
ELECTROMAGNETIC INTERACTIONS
ELECTRON-NUCLEON INTERACTIONS
ELECTRON-PROTON INTERACTIONS
ELECTROPRODUCTION
ELEMENTARY PARTICLES
ENERGY RANGE
GEV RANGE
GEV RANGE 10-100
HADRONS
INTERACTIONS
LEPTON-BARYON INTERACTIONS
LEPTON-HADRON INTERACTIONS
LEPTON-NUCLEON INTERACTIONS
LINEAR MOMENTUM
MATHEMATICAL MODELS
MESON RESONANCES
MESONS
ORIENTATION
PARTICLE INTERACTIONS
PARTICLE MODELS
PARTICLE PRODUCTION
PARTON MODEL
PIONS
PIONS NEUTRAL
PSEUDOSCALAR MESONS
QUARK MODEL
RESONANCE PARTICLES
SPIN ORIENTATION
SYNCHROTRONS
TRANSVERSE MOMENTUM