Evidence is presented for a new meson resonance at 2340±20 MeV, with a width of 180±60 MeV, decaying primarily into ρρπ. The resonance, which is observed in 15-GeV/c π+p interactions, has isotopic spin 1 or 2 and odd G parity. The cross section for production of the ρρπ state is 7.3±1.7 μb. Branching ratios into ρρπ and other decay modes are given.
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.
Using a 16-GeV linearly polarized photon beam, we have measured asymmetries in the process γN→K+(Λ+Σ) from hydrogen and deuterium, for square of four-momentum transfer, t, between -0.01 and -0.8 (GeV/c)2. The data show that for −t≳0.1 (GeV/c)2, the cross sections for γp→K+Λ, γp→K+Σ0, and γn→K+Σ− are strongly dominated by natural-parity exchange, as is the case in single-pion photoproduction.
No description provided.
We present evidence for δ production in the reactions K − p→ Σ (1385) + δ − ; δ − → η 0 π − , and K − p → Λδ + π − ; δ + → η 0 π + , in a bubble chamber experiment with beam momentum in the range 3.1 to 3.6 GeV/ c . The η 0 from the δ decay is seen both as a missing mass effect, and in its charged decay modes. The δ − has a mass of 989 ± 4 MeV, and width a of 16 −16 +25 MeV (after allowing for experimental resolution). The cross section for Σ(1385) − δ − production is 7±3 μ b; the reaction is produced at small momentum transfers. The mass and width of the δ + are consistent with those of the δ − , and the cross section for the Λ 0 π − δ + final state is about 5 μb. Neither δ appears to be produced as a result of D 0 decay.
No description provided.
A comparison is made of the properties and production mechanisms of the π + ω and K − ω systems produced in the reactions π + p → π + ω p at 4, 5, 8 and 16 GeV/ c and K − p → K − ω p at 10 and 16 GeV/ c . In the π + ω case apeak is observed at 1.23 GeV (the B meson), while the K − ω mass distribution has a threshold enhancement. The cross section of the low mass (<2.0 GeV) π + ω system falls as p lab −2 , while that of the low mass (<2.0 GeV) K − ω system is almost constant with energy, indicating diffractive production of the K − ω system, but not of the πω system. Using a modified version of the Illinois partial-wave analysis program, it is found that the K − ω system is dominantly produced in the J P = 1 + state with small contributions of 0 − and 2 + , mainly by natural parity exchange - as is found for reactions such as K − p → (K − π + π − )p which are predominantly diffractive. For the π + ω system in the B mass region, J P = 1 + states, produced mainly by natural parity exchange are found; the contributions of 0 − P, 1 − P, 2 − P and 2 + D are consistent with zero. The 1 + D state occurs in the π + ω case but not in the K − ω system, nor in the K ππ − system produced in the K − p → K ππ p reaction.
No description provided.
No description provided.
FROM BREIT-WIGNER FIT TO B EVENTS AND CORRECTED FOR UNSEEN OMEGA DECAY MODES.
As part of a program to determine proton-proton elastic-scattering amplitudes, we have measured the spin-spin correlation parameter CNN at 6 GeV/c. Measurements were made over the |t| range of 0.08 to 1.4 (GeV/c)2 using a polarized beam and a polarized target at the Argonne National Laboratory Zero Gradient Synchrotron.
No description provided.
In an exposure of the Argonne National Laboratory 12-foot hydrogen bubble chamber to a beam of 12.4-GeV/c protons, we have measured the total and differential cross sections for the inclusive reactions p+p→γ+X, π0+X, K0+X, and Λ+X, as well as estimates for the inclusive η and Σ0 cross sections. We present the average number of π0, K0, and Λ as a function of the associated charge multiplicity. We observe that the average charge multiplicity in pp collisions is the same whether or not a π0, K0, or Λ is also produced in the interaction. Invariant cross sections are presented as a function of PT2 and x, the Feynman scaling variable. The π0 differential cross sections are consistent with the relation dσdP(π0)=12[dσdP(π+)+dσdP(π−)] for all pion momenta P. The differential cross section for Λ production indicates a break in the distribution of |t−tmin|=1.4 (GeV/c)2. The polarization of the Λ's is found to be consistent with zero for all values of x.
No description provided.
From a 150 000-photograph exposure, we analyzed the p¯d→p¯psn reaction, ps denoting a proton stopping in the deuterium-filled bubble chamber. Choosing kinematical regions in which the ps can be recognized as a spectator, we studied the p¯n→p¯n process. From the observed p¯n diffraction peak, we obtained an exponential slope for the four-momentum-transfer distribution of bn=9.4±0.8 (GeV/c)−2, the elastic p¯n cross section being estimated as σe(p¯n)=16.5±2.4 mb. The present values in conjunction with those obtained at ≈1.8 and 3.5 GeV/c show that in this region bn and σe(p¯n) decrease with increasing incident momentum. We compared our data with the reactions np→np at ≈5.4 GeV/c and p¯p→p¯p at 5.7 GeV/c. The p¯n→p¯n and np→np differential cross sections exhibit a crossover phenomenon while p¯p and p¯n elastic scattering show an isospin dependence. We also analyzed the p¯d→p¯psn reaction by means of the Glauber formalism.
No description provided.
No description provided.
The angular distribution of 2720 tracks of 1085 hadronic final states produced from (e+e-) annihilation has been studied in the 1.2 to 3.0 GeV total centre-of-mass energy range. If we parametrize the angular distribution in terms off(θ) =1 + A cos2 θ, where 6 is the angle between the hadronic track produced and the colliding-beam direction, the results show thatA is less than 0.21, with 90% confidence.
ANGULAR DISTRIBUTION OF CHARGED HADRONS FOUND TO BE 1 + (0.07 +- 0.11)*(COS(THETA)**2).
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