Diproton resonances in the mass region 2100 to 2800 MeV. [Dispersion relations, scattering amplitude]
A striking energy dependence was observed in the difference between the p--p total cross sections for parallel and antiparallel longitudinal spin states, ..delta..sigma/sub L/ = sigma/sup Tot/(reverse ..-->..)-sigma/sup Tot/(double ..-->..). The structure appears around P/sub lab/ = 1.5 GeV/c where ..delta..sigma/sub L/ = -16.7 mb and is seen in sigma/sup Tot/(double ..-->..) rather than sigma/sup Tot/(reverse ..-->..). The experiments were performed at Argonne National Laboratory using a standard transmission technique. From the dispersion analysis of a forward p--p scattering amplitude using the data on ..delta..sigma/sub L/, Grein and Kroll have shown that the Argand plot of the amplitude has a clear resonance-like behavior around proton-incident momentum of 1.5 GeV/c. At the same energy range, the p--p polarization at fixed -+ also shows a remarkable energy dependence. In addition, a prominent energy dependence was observed for C/sub LL/, the spin correlation parameter for elastic pp scattering with beam and target both longitudinally polarized. The possibility of a resonance was further pursued by studying Legendre expansion coefficients of p--p differential cross section and polarization data. The analysis showed a partial wave, /sup 3/F/sub 3/ consistent with having a resonant behavior. Based on a phase-shift analysis, Hoshizaki also showed that /sup 3/F/sub 3/ seems to resonate. This resonant state would have the quantum number J/sup P/ = 3/sup -/, mass approx. 2260 MeV, width approx. 200 MeV and elasticity 20 to 30%. This exotic state may be described by the MIT bag model. Also speculated are several more diproton resonances in the mass region 2100 to 2800 MeV. 37 references.
- Research Organization:
- Argonne National Lab., IL (USA)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 6506884
- Report Number(s):
- ANL-HEP-CP-78-52; CONF-780967-2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
ANGULAR MOMENTUM
BAG MODEL
BARYON RESONANCES
BARYON-BARYON INTERACTIONS
BARYONS
COMPOSITE MODELS
CORRELATIONS
CROSS SECTIONS
DIBARYON RESONANCES
DIFFERENTIAL CROSS SECTIONS
DISPERSION RELATIONS
ELASTIC SCATTERING
ELEMENTARY PARTICLES
ENERGY DEPENDENCE
EXTENDED PARTICLE MODEL
FERMIONS
FUNCTIONS
HADRON-HADRON INTERACTIONS
HADRONS
INTERACTIONS
LEGENDRE POLYNOMIALS
MASS
MATHEMATICAL MODELS
NUCLEON-NUCLEON INTERACTIONS
PARITY
PARTIAL WAVES
PARTICLE INTERACTIONS
PARTICLE MODELS
PARTICLE PROPERTIES
PARTICLE WIDTHS
PHASE SHIFT
POLARIZATION
POLYNOMIALS
PROTON-NUCLEON INTERACTIONS
PROTON-PROTON INTERACTIONS
QUANTUM NUMBERS
QUARK MODEL
RESONANCE PARTICLES
SCATTERING
SCATTERING AMPLITUDES
SERIES EXPANSION
SPIN
TOTAL CROSS SECTIONS