D meson production in e/sup +/e/sup -/ annihilation
The production of D mesons in e/sup +/e/sup -/ annihilation for the center-of-mass energy range 3.7 to 7.0 GeV has been studied with the MARK I magnetic detector at the Stanford Positron Electron Accelerating Rings facility. We observed a resonance in the total cross-section for hadron production in e/sup +/e/sup -/ annihilation at an energy just above the threshold for charm production. This resonance, which we name psi'', has a mass of 3772 +- 6 MeV/c/sup 2/, a total width of 28 +- 5 MeV/c/sup 2/, a partial width to electron pairs of 345 +- 85 eV/c/sup 2/, and decays almost exclusively into D anti D pairs. The psi'' provides a rich source of background-free and kinematically well-defined D mesons for study. From the study of D mesons produced in the decay of the psi'' we have determined the masses of the D/sup 0/ and D/sup +/ mesons to be 1863.3 +- 0.9 MeV/c/sup 2/ and 1868.3 +- 0.9 MeV/c/sup 2/ respectively. We also determined the branching fractions for D/sup 0/ decay to K/sup -/..pi../sup +/, anti K/sup 0/..pi../sup +/..pi../sup -/ and K/sup -/..pi../sup +/..pi../sup -/..pi../sup +/ to be (2.2 +- 0.6)%, (4.0 +- 1.3)%, and (3.2 +- 1.1)% and the branching fractions for D/sup +/ decay to anti K/sup 0/..pi../sup +/ and K/sup -/..pi../sup +/..pi../sup +/ to be (1.5 +- 0.6)% and (3.9 +- 1.0)%. The average number of kaons per D decay was found to be 0.52 +- 0.14 K/sup 0/,s and 0.42 +- 0.12 K/sup +/,s. The rate for inclusive production of D mesons at center-of-mass energies above the psi'' has been measured; we find that it can account for most, if not all, of the observed increase in the total hadronic cross-section for center-of-mass energies above 4 GeV. The inclusive momentum and energy spectra for D's have been measured at the highest available center-of-mass energy (7 GeV). The energy spectra are rapidly decreasing functions of energy with a slope similar to the slope of the charged pion spectrum at the same center-of-mass energy. This behavior suggests that the fragmentation function of the charmed quark into charmed mesons is a decreasing function of the scaling variable z = 2E/sub D//E/sub CM/.
- Research Organization:
- Stanford Univ., CA (USA)
- OSTI ID:
- 5280173
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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D Meson Production in e+e- annihilation [Thesis; 3. 7 to 7. 0 GeV, total cross section, branching ratio]
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Related Subjects
D-1865 RESONANCES
PARTICLE PRODUCTION
WEAK PARTICLE DECAY
ELECTRON-POSITRON INTERACTIONS
ANNIHILATION
PSI-3772 RESONANCES
BRANCHING RATIO
CHARM PARTICLES
ELECTRON-RING ACCELERATORS
ENERGY SPECTRA
EXPERIMENTAL DATA
GEV RANGE 01-10
INCLUSIVE INTERACTIONS
KAONS
MASS
PARTICLE WIDTHS
PIONS
QUARKS
ACCELERATORS
BASIC INTERACTIONS
BOSONS
CHARMED MESON RESONANCES
COLLECTIVE ACCELERATORS
D RESONANCES
DATA
DECAY
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
ENERGY RANGE
GEV RANGE
HADRONS
INFORMATION
INTERACTIONS
LEPTON-LEPTON INTERACTIONS
MESON RESONANCES
MESONS
NUMERICAL DATA
PARTICLE DECAY
PARTICLE INTERACTIONS
PARTICLE PROPERTIES
POSTULATED PARTICLES
PSEUDOSCALAR MESONS
PSI RESONANCES
RESONANCE PARTICLES
SPECTRA
STRANGE PARTICLES
VECTOR MESONS
645101* - High Energy Physics- Particle Interactions & Properties-Experimental- Electromagnetic Interactions & Properties
645102 - High Energy Physics- Particle Interactions & Properties-Experimental- Weak Interactions & Properties