Results are presented from a search for the production of narrow p¯p states in antiproton interactions at 8.3 and 13.0 GeV/c. Cross-section upper limits have been established for four candidate baryonium states. The upper limits (95% probability level) range from 0.21 to 1.29 μb for inclusive forward production, and from 0.11 to 0.89 μb for backward production in the final state ωf0(p¯p).
CROSS SECTIONS ARE UPPER LIMITS OF 95 PCT CL.
CROSS SECTIONS ARE UPPER LIMITS OF 95 PCT CL.
We present the results of an experiment to search for associated charm production near threshold in 13-GeV/c π−p interactions. A large aperture PWC spectrometer was sensitive to the decay fragments of the forward-produced D*−’s expected from the two-body reactions π−+p→D*−+Λc+,Σc +,. . . . The missing baryon mass was determined from the vector momenta of the incident pion and the candidate D*−. No evidence for these reactions was found, which resulted in a 7-nb upper limit (95% confidence level) for each of the cross sections σ(π−p→D*−Λc+) and σ(π−p→D*−Σc+).
Axis error includes +- 0.0/0.0 contribution (?////NOT GIVENDECAY-BR(BRN=D*(2010)- --> AD0 PI-,BR=64 IN PCT)//DECAY-BR(BRN=AD0 --> K+ PI-, BR=3 IN PCT)).
No description provided.
None
DISTRIBUTION IS PRESENTED IN THE BEAM FRAGMENTATION REGIONS.
DISTRIBUTION IS PRESENTED IN THE BEAM FRAGMENTATION REGIONS.
DISTRIBUTION IS PRESENTED IN THE BEAM FRAGMENTATION REGIONS.
None
TYPICAL QUASIELASTIC ANGULAR DISTRIBUTION FOR NUCLEAR TARGET. OTHER DATA ARE IN ASHFORD ET AL (1985-PHYS REV C).
ABSORPTION CROSS SECTIONS.
No description provided.
We have studied the absorption cross section of antiprotons on Al, Cu, and Pb for T=131.6 and 193.6 MeV. These results are compared with predictions of an optical model fitted to antiproton elastic scattering data on these nuclei and are in agreement with these predictions. The cross sections have an exponential dependence on the mass number A with an exponent of approximately 0.61.
No description provided.
We have studied antiproton elastic scattering on Al, Cu, and Pb for two incident momenta: 514 and 633 MeV/c. The angular region covered extends from the forward Coulomb region to approximately 30 deg. The differential cross sections were analyzed using a nonrelativistic optical potential of the Woods-Saxon form, with the imaginary shape taken from electron scattering data. We obtained fits for the strengths of the real and imaginary parts of the potential, (V0, W0), of (51, 116) MeV for Al, (12, 71) MeV for Cu, and (12, 278) MeV for Pb.
No description provided.
None
.
.
.
High yields of low-momentum pions were obtained from high-energy primary proton beams. The results are discussed, also with respect to the possibility of setting up cloud muon beams from the very lowmomentum poins produced by 10 GeV/c protons.
Data obtained with 30 cm long target.
Using the CLEO detector at the Cornell $e~+e~-$ storage ring, CESR, we study the two-photon production of $\Lambda \overline{\Lambda}$, making the first observation of $\gamma \gamma \to \Lambda \overline{\Lambda}$. We present the cross-section for $ \gamma \gamma \to \Lambda \overline{\Lambda}$ as a function of the $\gamma \gamma$ center of mass energy and compare it to that predicted by the quark-diquark model.
No description provided.
No description provided.
No description provided.
The Λ polarization and the differential cross section for the reaction γ+p→K++Λ have been measured, using the Caltech synchrotron, at 90° in the c.m. system and at laboratory photon energies of 1100, 1200, and 1300 MeV. Protons from the asymmetric decay of the Λ were detected by counters placed above and below the production plane. Kaons were identified by their behavior in a thick range telescope. Polarization results were PΛ=+0.34±0.09 at 1100 MeV, +0.30±0.07 at 1200 MeV, and +0.08±0.07 at 1300 MeV, where PΛ was measured in the p^γ×p^Λ direction. The differential cross section was constant with energy at 0.14±0.01 μb/sr. Although the apparent bump in the polarization at 90° at a total energy of ≈1700 MeV adds support to models which invoke a resonance here, no really new conclusions can be reached.
No description provided.
No description provided.