The hadron fractions in photon-photon collisions

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:5539150

Lin, W T

The author has studied the reaction e{sup {plus}}e{sup {minus}} {yields} e{sup {plus}}e{sup {minus}{gamma}{gamma}} {yields} e{sup {plus}}e{sup {minus}} {plus} hadrons using the Time Projection Chamber (TPC) at the PEP storage ring at Stanford Linear Accelerator Center (SLAC). The final state particles are identified by measuring their ionization energy loss rate (dE/dx) and momentum. The data sample corresponds to an integrated luminosity of 67 pb{sup {minus}1} at {radical}s {equals} 29 GeV where only events containing a single tag with Q{sup 2} {ge} 0.03 GeV{sup 2} are considered. The Quark Parton Model (QPM) and Vector-meson Dominant Model (VDM) are used to explain the hadron productions in twophoton process. We use the Lund 5.3 for the quark fragmentation. The fractions of {pi}{sup {plus minus}}, K{sup {plus minus}} and p{bar p} are studied in both data and Monte Carlo events. The data shows the {gamma}{gamma} characteristic in favor of the VDM. No significant evidence has been found for the charm threshold in two-photon process at {radical}s {equals} 29 GeV.

• Research Organization: California Univ., Riverside, CA (United States)
• OSTI ID: 5539150
• 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
BASIC INTERACTIONS
COMPOSITE MODELS
ELECTROMAGNETIC INTERACTIONS
ELECTRON-POSITRON INTERACTIONS
ELEMENTARY PARTICLES
ENERGY LOSSES
FERMIONS
FINAL-STATE INTERACTIONS
HADRONS
INTERACTIONS
IONIZATION
LEPTON-LEPTON INTERACTIONS
LOSSES
MATHEMATICAL MODELS
PARTICLE INTERACTIONS
PARTICLE MODELS
PARTICLE PRODUCTION
PEP STORAGE RINGS
PHOTON-PHOTON INTERACTIONS
POSTULATED PARTICLES
QUARK MODEL
QUARKS
STORAGE RINGS
TIME PROJECTION CHAMBERS