Measurements of the cross section for the production of electron pairs with invariant masses between 4 and 8.7 GeV are presented as a function of the centre-of-mass energy ( s = 28 to s = 62 GeV ) of the colliding proton beams. A significant excess of events is observed in the region 8.7 to 10.3 GeV; these are ascribed to the ϒ(9.5 GeV) resonances and estimates of the production cross sections are given.
Axis error includes +- 40/40 contribution (Due to the uncertainty in efficiency).
Axis error includes +- 40/40 contribution (Due to the uncertainty in efficiency).
Data from a study of electron pairs produced in pp collisions (√ s = 5 and 63 GeV) are used to extend measurements of the scaling function down to m /√ s ≈ 0.07 (4.5 < m < 19 GeV). The dilepton continuum can be described by the scaling formula (fx475-1)
No description provided.
No description provided.
Inclusive π 0 production at 90° has been studied at the ISR at s 1 2 = 52.7 and 62.4 GeV over the p T range from 7 to 15 GeV/ c . The two photons from π 0 decay yielded overlapping electromagnetic showers in the liquid-argon-Pb plate calorimeter detector system. Any direct photon production is included in these measurements. For large values of p T , the cross section is observed to decrease with p T more slowly than the p T −8 behaviour which has been observed at lower values of p T .
No description provided.
The inclusive η production cross section at the CERN ISR has been measured for p T values of up to 11 GeV/ c . We find that the η π 0 cross-section ratio has an average value of 0.55 ± 0.07 and varies little with p T .
No description provided.
Evidence is presented for production of Ξ* resonances, decaying into Ξπ, Ξ(1530)π, ΛK¯, and ΣK¯, in K−p interactions at 2.87 Gev/c. The data represent final combined results from a 30-events/μb hydrogen exposure and an 18-events/μb exposure in deuterium designed to study Ξ* production in the mass interval 1.46-2.07 GeV/c2. In addition to Ξ(1820) and Ξ(1940), signals have been observed at masses of 1630 MeV/c2 and 1860 MeV/c2 decaying into Ξ−π+ and YK¯, respectively. Reaction cross sections have been measured for all final states containing two visible signs of strangeness, and for the final states ΛK−K+ and Σ0K−K+.
CROSS SECTIONS ARISING FROM VARIOUS TOPOLOGIES.
No description provided.
UPPER LIMITS ARE AT 90 PCT CONFIDENCE LEVEL. XI(1870) IS CALLED XI(1860) BY AUTHORS.
An investigation has been performed of some properties of Σ(1660) produced in the reaction K−p→Σ+(1660)π− at 2.87 GeV/c incident K− momentum. The decay modes observed for this state include Λ(1405)π and Σπ. The spin and parity are measured to be JP=32−. The differential cross section of the Λ(1405)π decay mode is sharply peaked in the forward direction, falling exponentially with a slope of 5.6 ± 0.7 (GeV/c)−2, while the slope for the Σ0π+ decay mode is 2.1 ± 0.4 (GeV/c)−2. The difference in the ratio of backward to total events for the two decay modes also suggests that two Σ(1660)'s exist.
No description provided.
No description provided.
The inclusive production of π 0 at large values of p T in pp collisions at the ISR has been studied. In this experiment the two photons are resolved and separately measured for p T values of up to 6 GeV/ c , giving confidence that the desired signal has been separated from various backgrounds.
No description provided.
Inclusive π 0 production has been measured at the CERN Intersecting Storage Rings in αα and α p collisions near 90°, for p T between 2 and 5 GeV/c. The differential cross sections show a slower exponential fall-off with p T than has been observed in pp collisions at the corresponding nucleon-nucleon centre-of-mass energies at large p T . The ratio of the π 0 production cross sections for αα collisions to those for pp collisions is observed to be larger than 16.
As a part of the study of the inclusive production of electron pairs in pp collisions at the CERN Intersecting Storage Rings (ISR), a search has been performed for additional photons accompanying J/ψ particles. The results suggest that (43±21)% of the J/ψ's are produced via the photonic decay of one of the χ(3.5) states.
The cross section times branching ratio.
We present the B( d θ d y ) y=0 for J /ψ over thefull range of ISR energies and for ϒ at √ s = 53 and 63 GeV, using their dielectron decay mode. The average transverse momentum and the decay angles are presented. We found ( p T ) = 1.75 ± 0.19 GeV for ϒ, being higher than ( p T ) of the continuum and rising with √s. We present a comparison of the cross sections of J/ψ and ϒ with those of the continuum, at the same masses, as a function of √s. An appropriate scaling of the hadronic production of quark-antiquark narrow bound states involving ⋉, J/ψ, ψ′, ϒ, and ϒ′ is presented as a function of m /√ s at y = 0, and is compared with Drell-Yan scaling.
No description provided.
UPSILON HERE = UPSILON+UPSILON PRIME.