Exposures of the Ne/H 2 filled Big European Bubble Chamber (BEBC) to a dichromatic neutrino (antineutrino) beam produced by 400 GeV protons of the CERN SPS yielded ∼ 3100 events with a negative, and ∼ 1100 with a positive, muon. The neutrino flux is determined from the muon flux in the shielding. Assuming a linear energy dependence of the cross section, the values σ E between 20 and 200 GeV are found to be 0.657 ± 0.012 (stat.) ± 0.027 (syst.) and 0.309 ± 0.009 (stat.) ± 0.013 (syst.) cm 2 (GeV nucleon) −1 , for neutrinos and antineutrinos, respectively. The scaling variable q 2 E decreases significantly with increasing energy both for neutrinos and antineutrinos.
Measured charged current total cross section.
Measured charged current total cross section.
No description provided.
A search for production of D*−'s using the decay chain D0π−, D0→K+π−, was carried out at the Brookhaven National Laboratory multiparticle spectrometer with a 16-GeV/c π− beam and a hydrogen target. At 95% confidence level the upper limits for the product of peripheral production cross section by branching ratio are 2.4 nb for inclusive D*− production and 1.3 nb for the exclusive channel π−p→D*−Λc.
UPPER LIMIT TO CROSS SECTIONS.
The reaction π − p → K + K − π − p at 16 GeV/ c was studied in the CERN OMEGA spectrometer and a partial-wave analysis (PWA) of the low-mass (K + K − π − ) system (1.3–2.0 GeV) was performed. Only states in the unnatural spin-parity series produced by natural parity exchange are important and they approximately conserve t -channel helicity. The 1 + S K ∗ K wave dominates the low-mass (K + K − π − ) region. We observe an enhancement in 2 − P K ∗ K wave at a mass of 1.7 GeV, consistent with the decay of the A 3 resonance.
TOTAL ACCEPTANCE CORRECTED CROSS SECTION.
ACCEPTANCE CORRECTED.
MOST IMPORTANT CONTRIBUTING STATES CORRECTED FOR ACCEPTANCE.
Large transverse energy cross sections of 300 GeV/ c pions and protons on hydrogen have been measured with a segmented calorimeter covering the central rapidity region −0.88 < y < 0.67 and 2 π in azimuth. The selected events show large multiplicities and no jet-like event structure. Processes more complicated than the scattering of two constituents appear to dominate these inelastic collisions.
No description provided.
No description provided.
No description provided.
Narrow baryonium production in the baryon exchange reactions K − p → Λ p p and K − p → pK − p p at 18.5 GeV/ c is investigated in a 12 events/nb experiment performed at the CERN Ω′ spectrometer. No narrow structure is observed in the p p mass spectra. Upper limits for production of baryonium states are given as a function of p p mass.
'1'. (AP P) SYSTEM PRODUCED IN BACKWARD DIRECTION IN THE CMS.
'1'. (AP P) SYSTEM PRODUCED IN BACKWARD DIRECTION IN THE CMS.
Production of ϱ 0 , K ∗0 , K ∗0 , and φ have been measured in proton-proton collisions at the CERN Intersecting Storage Rings (ISR) at low p T in the central region. The transverse mass spectra are well described by exp (− aμ T ), with a = −6.4±0.2 GeV −1 . The cross sections for d σ/ d y| y=0 are 6.5±0.8±1.2 mb for ϱ 0 , 1.9±0.3±0.3 mb for K ∗) , 1.9±03±03 mb for K ∗0 , and 60.±0.12±0.13 mb for φ , where the first error is statistical and the second is sytematic.
No description provided.
No description provided.
The final state K − pn has been analyzed in a K − deuterium bubble chamber experiment at K − momenta between 680 and 840 MeV/ c . Differential cross sections for elastic K − p and K − n scattering in the c.m. energy range of 1.60–1.74 GeV are presented. The results for K − p→K − p agree well with existing data obtained with hydrogen targets. The results for K − n→K − n are lower but still compatible with recent measurements from a counter experiment.
No description provided.
No description provided.
PLAB IS THE EFFECTIVE KAON LAB MOMENTA CORRESPONDING TO THE GIVEN CM ENERGY ASSUMING AN ON-SHELL TARGET NUCLEON AT REST.
We report on the interactions of an incident 200 GeV / c beam composed of 33% protons, 16% kaons, and 48% pions on targets of silver and gold mounted in the Fermilab 30″ bubble chamber. Within our limited statistics, we find the total cross sections and average multiplicities to agree with previously published data. We find the KNO scaling distribution curve to be broader for heavy nuclei than for hydrogen. We present the first data for V 0 production on gold and silver. We also present, for the first time, evidence for a positive charge excess among the sample of relativistic tracks from interactions on gold and silver. We observe a trend where the positive charge excess increases with target atomic number and with increasing charged particle multiplicity. We find the charge excess to exist among the sample of particles having greater than 2 GeV / c momentum and to persist in the sample with momentum greater than 4 GeV / c .
SIG REFERS PRODUCTION OF 2 OR MORE CHARGED PARTICLES EXCLUDING ELASTICS BUT INCLUDING COHERENT PRODUCTION. MULT REFERS TO RELATIVISTIC SECONDARIES (BETA > 0.7).
NO CORRECTION FOR GAMMA CONVERSIONS IN THE TARGET IN THIS TABLE BUT DIFFERENCE DOES NOT NEED CORRECTION.
No description provided.
Results from K± elastic and inelastic scattering from C12 and Ca40 are reported. The data were all taken at an incident momentum of 800 MeV/c over an angular range from 2° to 38°. The elastic data are compared to first-order optical model calculations in coordinate and momentum space; good qualitative agreement is obtained. The inelastic data (from C12 only) are compared to distorted-wave Born approximation calculations, and good agreement is found if "realistic" inelastic transition densities are used. Although a first-order optical potential description does not describe the data fully, there are strong indications of the increased penetrability of K+ over K− in this energy range. NUCLEAR REACTIONS C12(K±,K±)C12, Ca40(K±,K±)Ca40, E=442 MeV (800 MeV/c), measured σ(θ) for elastic and inelastic scattering, compared to optical model and DWBA calculations, deduced optical potential parameters; θ=2°−38°, Δθ=1°.
X ERROR D(THETA) = 1.0100 DEG.
X ERROR D(THETA) = 1.0100 DEG.
X ERROR D(THETA) = 1.1000 DEG.
We report on inclusive K 0 production in the region of the upsilon resonances (9.4–10.6 GeV). The K 0 yield for the resonances and continuum below the B B threshold is found to be constant at 0.82 ± 0.10 K 0 per observed hadronic event. At the ϒ (4S), however, the K 0 yield is significantly higher, 1.58 ± 0.35. This increase in K 0 production and the differential cross section d σ /d p of kaons are consistent with B B decay of the ϒ (4S) resonance with the bottom quarks subsequently decaying primarily into charmed quarks.
No description provided.
ACCEPTANCE CORRECTED INCLUSIVE K0 MOMENTUM DISTRIBUTION AT THE UPSI(10570)0.
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