Andrews, Jason
Max results
Sort by Reverse order

Showing 10 of 2030 results

Date

rivet Analysis
DECAY OF B MESONS INTO CHARGED AND NEUTRAL KAONS

The CLEO collaboration Brody, A. ; Chen, A. ; Goldberg, M. ; et al.
Phys.Rev.Lett. 48 (1982) 1070-1074, 1982.
Inspire Record 180612 DOI 10.17182/hepdata.27749

Data on inclusive kaon production in e+e− annihilations at energies in the vicinity of the ϒ(4S) resonance are presented. A clear excess of kaons is observed on the ϒ(4S) compared to the continuum. Under the assumption that the ϒ(4S) decays into BB¯, a total of 3.38±0.34±0.68 kaons per ϒ(4S) decay is found. In the context of the standard B-decay model this leads to a value for (b→c)(b→all) of 1.09±0.33±0.13.

2 data tables
Table 1

No description provided.

Table 2

ACCEPTANCE CORRECTED MOMENTUM DISTRIBUTIONS FOR CONTINUUM AND UPSILON EVENTS WITH THE CONTINUUM SUBTRACTED.


Observation of a Fourth Upsilon State in e+ e- Annihilations

The CLEO collaboration Andrews, D. ; Berkelman, Karl ; Cabenda, R. ; et al.
Phys.Rev.Lett. 45 (1980) 219, 1980.
Inspire Record 153182 DOI 10.17182/hepdata.20674

A fourth state in the upsilon energy region has been seen in e+e− collisions at the Cornell Electron Storage Ring. A resonance is observed with a mass 1112±5 MeV above the lowest upsilon state. The 9.6-MeV rms width is greater than the 4.6-MeV energy resolution of the e+e− beams. The observed characteristics of the new state make it a likely candidate for the 4S3 state of the bb¯ system, lying above the threshold for the production of B mesons.

1 data table
Table 1

NOT CORRECTED FOR TAU HEAVY LEPTON PRODUCTION NOR TWO-PHOTON COLLISIONS.


Observation of Three Upsilon States

The CLEO collaboration Andrews, D. ; Berkelman, Karl ; Billing, M. ; et al.
Phys.Rev.Lett. 44 (1980) 1108, 1980.
Inspire Record 152393 DOI 10.17182/hepdata.20733

Three narrow resonances have been observed in e+e− annihilation into hadrons at total energies between 9.4 and 10.4 GeV. Measurements of mass spacing and ratios of lepton pair widths support the interpretation of these "ϒ" states as the lowest triplet-S levels of the bb¯ quark-antiquark system.

1 data table
Table 1

No description provided.


PHOTOPRODUCTION OF eta MESONS AT 9.7-GeV

Nelson, C.A., Jr. ; Abramson, J. ; Andrews, D.E. ; et al.
Phys.Rev.D 19 (1979) 1931, 1979.
Inspire Record 132567 DOI 10.17182/hepdata.24307

Inclusive η photoproduction has been studied at 9.7 GeV, on hydrogen and deuterium targets. A simple, parameter-free ρ0-dominance model adequately fits the forward cross sections, but overestimates the cross section at large momentum transfer.

1 data table
Table 1

No description provided.


Experimental Study of Nuclear Shadowing in Photoproduction

Michalowski, S. ; Andrews, D. ; Eickmeyer, J. ; et al.
Phys.Rev.Lett. 39 (1977) 737-740, 1977.
Inspire Record 124559 DOI 10.17182/hepdata.20970

The total cross section for hadron production by high-energy photons has been measured from a number of nuclei ranging from hydrogen to uranium. Some shadowing is observed at a level considerably less than predicted by conventional vector-meson dominance but consistent with a modified theory. The energy dependence predicted by vectormeson dominance is observed. The shadowing in heavy nuclei shows a smooth transition from electroproduction to photoproduction.

1 data table
Table 1

No description provided.


Inelastic Photoproduction of omega and rho+- Mesons

Nelson, C.A., Jr. ; May, E.N. ; Abramson, J. ; et al.
Phys.Rev.D 17 (1978) 647, 1978.
Inspire Record 4373 DOI 10.17182/hepdata.24401

We report measurements of inelastic photoproduction of ω and ρ± mesons from hydrogen and deuterium at incident photon energies in the range 7.5-10.5 GeV. For ωΔ and ρ−Δ++ production, differential cross sections dσdt′ and spin density matrices are presented. For higher missing masses the cross sections dσdMX2 and invariant structure functions F(x) are also given. The data are compared to a one-pion-exchange model. We conclude that pion exchange is dominant for inelastic ω photoproduction, but unimportant for ρ±.

4 data tables
Table 1

CROSS SECTION PER NUCLEON FOR COMBINED HYDROGEN AND DEUTERIUM DATA ALLOWING FOR A GLAUBER CORRECTION FACTOR OF 0.88 FOR THE DEUTERIUM CROSS SECTIONS.

Table 2

HYDROGEN AND DEUTERIUM DATA COMBINED BY AVERAGING.

Table 3

OBTAINED BY EXTRAPOLATING A FIT TO D(SIG)/DT OVER -T = 0 TO 0.52 GEV**2.

More…

Rho+- Photoproduction at 9.6-GeV

Abramson, J. ; Andrews, D.E. ; Busnello, R. ; et al.
Phys.Rev.Lett. 36 (1976) 1432, 1976.
Inspire Record 108497 DOI 10.17182/hepdata.21105

ρ± photoproduction from hydrogen and deuterium at 9.6 GeV is studied. The reactions γp→ρ+n and γp→ρ−Δ++(1236) have cross sections much larger than expected from pion exchange alone. t distributions do not show the sharp forward peak characteristic of one-pion exchange contributions. Density matrices indicate an isotropic decay distribution. The ratio of ρ+ to ρ− production on deuterium differs from unity and by the amount expected from interference between ρ and A2 exchanges. We conclude that π exchange is unimportant for ρ± photoproduction, and infer that ρ exchange dominates.

7 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

DENSITY MATRICES IN HELICITY FRAME - UNPUBLISHED.

More…

Version 2
Elastic Photoproduction of omega Mesons from Hydrogen, Deuterium, and Complex Nuclei

Abramson, J. ; Andrews, D.E. ; Harvey, John R. ; et al.
Phys.Rev.Lett. 36 (1976) 1428, 1976.
Inspire Record 108496 DOI 10.17182/hepdata.21101

We have studied ω photoproduction using 7.5- to 10.5-GeV tagged photons. Cross sections from hydrogen lie 22% below the bubble chamber results of Ballam et al., but have a similar slope. Density matrices indicate approximate s-channel helicity conservation. The proton-neutron cross-section difference is midway between zero and the value suggested by the γp−γn total-cross-section difference. Fits to the cross sections for D, Be, and Cu and those for Be, C, Al, Cu, and Pb from a previous experiment yield σωN=25.4±2.7 mb and γω24π=7.6±1.2.

6 data tables
Table 2

FORWARD CROSS SECTION IS 366 +- 49 MUB/GEV**2 AND SLOPE IS 47.1 +- 8.0 GEV**-2.

Table 3

FORWARD CROSS SECTION IS 9.56 +- 1.24 MB/GEV**2 AND SLOPE IS 160 +- 23 GEV**-2.

More…

An Improved Upper Limit for Photoproduction of psi (3105) Near Threshold

Andrews, D.E. ; Harvey, John R. ; Lobkowicz, F. ; et al.
Phys.Rev.Lett. 34 (1975) 1134-1136, 1975.
Inspire Record 98255 DOI 10.17182/hepdata.21225

An improved upper limit for ψ photoproduction near threshold is presented.

1 data table
Table 1

The branching ratio for J/PSI --> E+ E- is taken as 0.06.


Search for photoproduction of psi(3105)

Andrews, D.E. ; Harvey, J. ; Lobkowicz, F. ; et al.
Phys.Rev.Lett. 34 (1975) 231-233, 1975.
Inspire Record 106690 DOI 10.17182/hepdata.60290

The product of the photoproduction cross section at 11.1 GeV for ψ(3105) on nucleons times the branching ratio for ψ into e+e− is less than 75 pb, at the 90% confidence level. This result implies a ψ-nucleon total cross section of less than 1.2 mb.

1 data table
Table 1

The branching ratio for J/PSI --> E+ E- is taken as 0.06.