Search for backwards produced exotic meson resonances and study of particle spectra and mass distributions in the reaction. pi. /sup +/ + P. -->. n (forward) + X/sup + +/ at 8. 4 GeV/c. [Upper limits, G parity, 8. 4 GeV/c]

Technical Report · Fri Aug 01 04:00:00 EDT 1975

DOI:https://doi.org/10.2172/7348938· OSTI ID:7348938

Alam, M S; Brabson, B B; Galloway, K

Results are reported from a hybrid experiment designed to search for backwards produced I = 2 exotic meson resonances by investigating the backward scattering reactions: ..pi../sup +/ + p ..-->.. in (forward) + ..pi../sup +/..pi../sup +/, ..pi../sup +/..pi../sup +/..pi../sup +/..pi../sup -/, ..pi../sup +/..pi../sup +/..pi../sup +/..pi../sup +/..pi../sup -/..pi../sup -/, and p anti p..pi../sup +/..pi../sup +/ at an incident pion momentum of 8.4 GeV/c. The SLAC 15'' rapid cycling bubble chamber, operating at 20 cycles per second, was triggered by detecting fast forward neutrons in an optical spark chamber and scintillation counter array downstream. Following two-component duality arguments, Jacob and Weyers and Rosner have suggested backward scattering processes as a favored mode for exotic meson resonance production. Upper limits of the order of one microbarn are reported for the production of narrow exotic meson resonances with masses less than or equal to 3 GeV and which could decay into even G-parity states: ..pi../sup +/..pi../sup +/, ..pi../sup +/..pi../sup +/..pi../sup +/..pi../sup -/, ..pi../sup +/..pi../sup +/..pi../sup +/..pi../sup +/..pi../sup -/..pi../sup -/, and p anti p..pi../sup +/..pi../sup +/. The mass resolution in the above channels varied from 5 to 30 MeV over the mass range for the most restrictive sample of events. The statistical significance of the data corresponds to 30 events per microbarn. Evidence for forward N* and rho/sup 0/ production are also reported. The main features of the data can be simulated by a Monte Carlo model which incorporates Lorentz-invariant phase space modified by exponential transverse momentum damping on each final state particle and, in addition, takes into account the geometrical constraints and trigger requirements of the experiment.

• Research Organization: Purdue Univ., Lafayette, Ind. (USA); Stanford Linear Accelerator Center, Calif. (USA); Vanderbilt Univ., Nashville, Tenn. (USA)
• OSTI ID: 7348938
• Report Number(s): COO-2009-113
• Country of Publication: United States
• Language: English

Related Subjects

645104* -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Strong Meson-Induced Interactions-- (-1987)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BARYON RESONANCES
BARYONS
BOSONS
BOUNDARY CONDITIONS
CROSS SECTIONS
ELEMENTARY PARTICLES
ENERGY RANGE
EXOTIC RESONANCES
FERMIONS
FINAL-STATE INTERACTIONS
G PARITY
GEOMETRY
HADRON-HADRON INTERACTIONS
HADRONS
INTERACTIONS
INVARIANCE PRINCIPLES
ISOSPIN
LIMITING VALUES
LINEAR MOMENTUM
LORENTZ INVARIANCE
MASS
MATHEMATICAL SPACE
MATHEMATICS
MESON RESONANCES
MESON-BARYON INTERACTIONS
MESON-NUCLEON INTERACTIONS
MESONS
MEV RANGE
MEV RANGE 01-10
MONTE CARLO METHOD
N RESONANCES
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
PARTICLE PROPERTIES
PHASE SPACE
PION PLUS-PROTON INTERACTIONS
PION-NUCLEON INTERACTIONS
PION-PROTON INTERACTIONS
PIONS
PIONS MINUS
PIONS PLUS
PSEUDOSCALAR MESONS
RESONANCE PARTICLES
RHO-765 RESONANCES
SPACE
STATISTICS
TRANSVERSE MOMENTUM
VECTOR MESONS