Dimuon production is studied in 400-GeV proton-nucleus collisions. A strong enhancement is observed at 9.5 GeV mass in a sample of 9000 dimuon events with a mass $m_{\mu^+\mu^-} \to$ 5 GeV.
Two peaks were observed. Mass spectrum was fitted to one and two resonance hypothesis.
Inclusive K ∗0 production is studied in π − p interactions at 16 GeV/ c with x ϝ > 0.2. The K ∗0 is found to be pre-dominantly centrally produced with cross section σ( K ∗0 ) = (72 ± 12) μb for x ϝ > 0.2 and compares closely to data on K ∗0 production in π + p interactions at the same energy.
No description provided.
No description provided.
No description provided.
The production of η(550) and ω(780) mesons is studied in π ± p interactions at 16 GeV/ c and K − p interactions at 10 and 16 GeV/ c . Cross sections for exclusive channels are presented, and for the π + p data differential cross sections are given for quasi-inclusive production where the η or ω is required to be accompanied by charged particles only. Close similarities are observed between η, ω and also ϱ 0 (770) production in terms of longitudinal and transverse variables. By a rough estimate, the η, ω and ϱ 0 inclusive yields are found to be in the ratio 0.32 : 0.85 : 1, respectively, for 16 GeV/ c π + p collisions. For non-peripheral production we estimate this same ratio to be 0.34 : 0.9 : 1.
Axis error includes +- 0.0/0.0 contribution (?////).
Axis error includes +- 0.0/0.0 contribution (?////).
DATA SUPPLIED BY A.A. LEBEDEV.
We present the inclusive and semi-inclusive production of protons, π+, π−, for the full range of kinematic variables, from 7850 inelastic interactions obtained in the 4.7 m liquid-hydrogen bubble chamber Mirabelle at the Serpukhov accelerator and with an incident proton beam of 69 GeV/c. We compare the data with those at other energies, and we give the results of different phenomenological fits.
No description provided.
No description provided.
No description provided.
Observation of 16 μ + μ − pairs of invariant mass greater than 2.7 GeV/ c 2 in the reaction pp → μ + μ − + anything at s = 52 GeV at the CERN Intersecting Storage Rings (ISR) is reported. These events can be interpreted as originating from J(3.1) decay into μ + μ − . Their p T distribution suggests a hadronic production. The cross section for J production is given and compared to the cross section for single lepton production. We conclude that J(3.1) production cannot fully account for single lepton production.
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.
In an exposure of the Fermi National Accelerator Laboratory 30-in. bubble chamber to a beam of 205-GeV/c protons, we have determined total and differential cross sections for the inclusive reactions p+p→γ+X, π0+X, (K0K¯0)+X, Λ+X. Invariant distributions in x indicate that for γ, K0, Λ production, scaling has set in somewhere before 69 GeV. The γ differential cross sections are consistent with the relation dσdPu(π0)=12[dσdPu(π+)+dσdPu(π−)] for all Pu, where Pu=PL* or P⊥. The differential cross sections for Λ and K0 production indicate a break in the distribution at |t−tmin|=1.5(GeVc)2 and 0.5(GeVc)2, respectively. The Λ polarization is found to be - (0.25 ± 0.26), consistent with zero throughout the x region.
No description provided.
We have measured cross section for γ , K S °, Λ and Λ production at 102 GeV/ c and find: σ ( γ ) = 170 ± 16 mb ., σ ( K S °) = 4.6 ± 0.5 mb ., σ ( Λ ) = 3.2 ± 0.4 mb ., and σ( Λ ) = 0.23 ± 0.10 mb. Both 〈 n π °〉 and 〈 n Ks °〉 appear to rise linearly with n - while the ratio 〈 n Ks °〉/〈 n π °〉 is approximately independent of n - . The integrated invariant cross section as a function of x as well as d σ /d y and d σ /d p T 2 are presented and compared with other data.
No description provided.
Data on the inclusive production spectra of K S 0 and Λ from proton-proton collisions at 19 GeV are presented and discussed in connection with the earlier studied inclusive π − production spectrum. The three single-particle spectra are compared with a crude two-center thermal model for the average radiation from the pp collisions.
No description provided.
Forum