The neutron-proton elastic differential cross section has been measured for incident momenta between 10 and 70 GeV/c and for values of the momentum transfer squared between 0.1 and 2.8 (GeV/c) 2 . The forward peak and the break at about ∣ t ∣ = 1 (GeV/ c ) 2 are very similar to corresponding pp data.
No description provided.
No description provided.
The asymmetry of the cross sections for the photoproduction of π + mesons on polarized protons γ + p↑ → π + + n has been studied in the four-momentum transfer range 0.1 ⩽ | t | ⩽ 1.25 (GeV/ c ) 2 for photon energies of 2.5, 3.4 and 5.0 GeV. The measurements were carried out on a polarized butanol target. Both particles in the final state were detected: the pion by a magnetic spectrometer, the recoil nucleon in a scintillation counter matrix. The asymmetry was found to be negative with values around −0.4.
No description provided.
No description provided.
No description provided.
A study of the reaction π + p → p π + π o at 16 GeV/ c incident momentum has been made using the prism plot analysis to reject background events arising from elastic and multineutral contaminations and to separate different reaction channels ( ϱ + p, g + p, Δ + π + , Δ ++ π o , π + (p π o ) DD ). Cross sections, invariant mass distributions and production and decay angular distributions are presented. For the channel corresponding to proton diffraction dissociation strong violation of both s - and t -channel helicity conservation is found for low values of the (p π o ) mass. We demonstrate that the prism plot method provides a better separation of background events than conventional methods using kinematic cuts.
STATISTICAL ERRORS ONLY.
No description provided.
We have searched the mass region 3.2 to 5.9 GeV for evidence of narrow resonances in e+e−→hadrons. We find no evidence for any such resonances other than the ψ(3695) in this region with a sensitivity ranging from about 12 to 45% of the integrated cross section of the ψ(3695). The more stringent bounds apply to resonances of a few MeV width, while the looser bounds apply to resonances of up to 20 MeV width.
EXTREAMLY GOOD DATA, MUST BE ASCED FROM AUTHORS.
The total cross section for hadron production by e+e− annihilation has been measured at center-of-mass energies between 2.4 and 5.0 GeV. Aside from the very narrow resonances ψ(3105) and ψ(3695), the cross section varies between 32 and 17 nb over this region with structure in the vicinity of 4.1 GeV.
No description provided.
MEAN CHARGED MULTIPLICITY. ERRORS ARE STATISTICAL ONLY.
A very narrow resonance with a mass of 3.1 GeV/c2 is observed in the reaction n+Be→μ++μ−+X. The total cross section for this process, as well as its P⊥2 and x distribution, are given.
The cross section per nucleon times the branching ratio.
A very narrow resonance with a mass of 3.105 GeV/c2 is observed in the reaction γ+Be→μ++μ−+X. The total cross section for this process, as well as its t distribution, is given.
THIS IS CROSS SECTION PER BERYLLIUM NUCLEUS ASSUMING ONLY COHERENT OR QUASI-ELASTIC SCATTERING FROM A SINGLE NUCLEON. FORWARD DIFFERENTIAL CROSS SECTIONS QUOTED IN TABLE 1 OF T. NASH ET AL., PRL 36, 1233 (1976).
A spin-parity analysis is performed of the low-mass (≤ 1.75 GeV/c2) pπ− system in diffractive np→(pπ−)p using new data at 13 GeV/c and 20 GeV/c. In the context of a Deck-plus-resonances model a good fit to the pπ− angular moments is found only if the Gribov-Morrison parity-change rule does not hold and spin states up to j=52 are included. In particular the presence of a considerable fraction of spin-parity ½− state is indicated.
DECK MODEL PLUS RESONANCES FIT TO DIFFRACTIVE EVENTS.
A study of elastic scattering, one-pion production and annihilation reactions in p p interactions at 5.7 GeV/ c was carried out, from the two-prong events, obtained in the hydrogen bubble chamber exposed at CERN.
NUMBER OF EVENTS FOR -T<0.03 GEV**2 CALCULATED BY EXTRAPOLATION.
No description provided.
Inclusive cross sections and one-particle inclusive spectra are given for neutral K, Λ and Λ produced in K − p and K + p interactions at 32 GeV/ c in the 4.5 m Mirabelle hydrogen bubble chamber at the Serpukhov accelerator. Cross sections for associated production are also given, and the energy dependences of the cross sections and of the x distributions in the central and in the fragmentation regions are discussed.
No description provided.
No description provided.