Characteristics of charm particles produced by 800-GeV P-P collisions

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5123545

Nguyen, A G

This thesis presents the results of Fermilab experiment E743, a study of the production characteristics of the D mesons in 800 GeV proton-proton collisions ({radical}s = 39 GeV), utilizing a high resolution, rapid cycling bubble chamber for vertex detection, and a multiparticle spectrometer for the momentum determination of charged particles. A relatively unbiased measurement of the D meson cross section is accomplished by direct observation of the decay vertices in the bubble chamber, {sigma}(D/D) = 59 {sub {minus}15}{sup +22}{mu}b. Also measured are the longitudinal and transverse momentum distributions of observed D meson decays. The differential production cross sections are described well by the form 1/{sigma} d{sup 2}{sigma}/dx{sub F}dp{sup 2}{sub T} = (n +1)(b/2) (1-{vert bar}xF{vert bar}){sup n}e{sup {minus}bp2T} with n = 11.0 {sub {minus}3.6}{sup +4.6} and b = 0.66{sub {minus}0.20}{sup +0.23} (GeV/C){sup {minus}2}. For {vert bar}xF{vert bar} > 0.3 we observe no events, which corresponds to an upper limit of 10 {mu}b at a 95% confidence level. When compared with measurements made at lower energies the results of this study point to a D meson cross section which is slowly rising with center of mass energy. These results are in sharp contrast with the results from a number of experiments performed at the CERN Intersecting Storage Rings (ISR) ({radical}s = 53-62 GeV) which indicated a dramatic rise in the charm particle cross sections with increasing energy. These large cross sections were observed in experiments which were sensitive to production at large x{sub F} values (typically s{sub F} > 0.3). Unusual mechanisms for charm production invoked to explain these large cross sections do not appear to be necessary below {radical}s = 39 GeV.

• Research Organization: Michigan State Univ., East Lansing, MI (USA)
• OSTI ID: 5123545
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400101 -- Activation
Nuclear Reaction
Radiometric & Radiochemical Procedures
645000* -- High Energy Physics
645103 -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Strong Interactions & Baryon & Meson Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ACCELERATORS
BARYON-BARYON INTERACTIONS
BOSONS
CHARM PARTICLES
CHARMED MESONS
CYCLIC ACCELERATORS
D MESONS
DATA
ELEMENTARY PARTICLES
ENERGY RANGE
EXPERIMENTAL DATA
FERMILAB ACCELERATOR
GEV RANGE
GEV RANGE 100-1000
HADRON-HADRON INTERACTIONS
HADRONS
INFORMATION
INTERACTIONS
MEASURING INSTRUMENTS
MEASURING METHODS
MESONS
NUCLEON-NUCLEON INTERACTIONS
NUMERICAL DATA
PARTICLE INTERACTIONS
PRODUCTION
PROTON-NUCLEON INTERACTIONS
PROTON-PROTON INTERACTIONS
PSEUDOSCALAR MESONS
SYNCHROTRONS