Berkelman, Karl
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Vector-meson electroproduction at high q-squared

Ahrens, L. ; Berkelman, Karl ; Brown, G.S. ; et al.
Phys.Rev.Lett. 31 (1973) 131-133, 1973.
Inspire Record 84487 DOI 10.17182/hepdata.47133

We have measured ρ0, ω (combined) and ϕ electroproduction over a range of virtual-photon four-momentum Q2 from 0.4 to 2.2 GeV2 and for photon energies ν from 2.7 to 8.6 GeV. We find that the slope of the t (momentum transfer) dependence of the ρ0 and ω forward peak decreases with increasing Q2 to less than half of the photoproduction slope.

1 data table
Table 1

The cross section for virtual photon are derived from E- P cross section bydividing on the virtual-photon flux factor.


LARGE ANGLE PROTON AND PION PRODUCTION IN DEEP INELASTIC ELECTRON SCATTERING

Ahrens, L. ; Berkelman, Karl ; Brown, G.S. ; et al.
Phys.Rev.D 9 (1974) 1894, 1974.
Inspire Record 80405 DOI 10.17182/hepdata.47134

We have measured ep, eπ+, and eπ− coincidences for scattered electrons in the range Q2=0.4 to 2.2 GeV2 and W=2 to 4 GeV. We find (a) that vector-meson production decreases with Q2 more rapidly than does the total virtual-photon-plus-proton cross section, more rapidly even than the prediction of simple vector dominance, (b) that the slope of the t distribution in ρ and ω production becomes flatter with increasing Q2 and seems to be at least approximately a function of the single variable xρ=(Q2+mρ2)2Mν, (c) that the fraction of final states containing a proton decreases with increasing Q2, (d) that in the central region of longitudinal momenta the inclusive π+ yield seems to increase relative to the π− yield as Q2 increases, and (e) that the average transverse momentum of π− is greater than of π+ in the central region of longitudinal momenta.

28 data tables
Table 1

No description provided.

Table 2

The data with (C=Q=RHO+OMEGA) are obtained by excluding the contribution from RHO and OMEGA production.

Table 3

No description provided.

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Large angle k+ p elastic scattering at 10 gev/c

Baglin, C. ; Briandet, P. ; Carlson, P.J. ; et al.
Phys.Lett.B 47 (1973) 89-92, 1973.
Inspire Record 95211 DOI 10.17182/hepdata.28014

K + p elastic scattering has been measured over nearly the whole angular range at an incident momentum of 10 GeV/ c . The differential cross-section is found to decrease smoothly in the forward direction to - t ≈ 2 (GeV/ c ) 2 , where there is a change in slope, followed by a further decrease to - t ≈ 6 (GeV/ c ) 2 . Around 90° c.m. the cross-section is approximately 1 nb/(GeV/ c ) 2 , which is more than two orders of magnitude lower than at 5 GeV/ c . The backward peak has no structure.

1 data table
Table 1

THESE DATA ARE REPORTED MORE FULLY IN C. BAGLIN ET AL., NP B98, 365 (1975).


Large angle pi+ p elastic scattering at 10 gev/c

Baglin, C. ; Briandet, P. ; Carlson, P.J. ; et al.
Phys.Lett.B 47 (1973) 85-88, 1973.
Inspire Record 95213 DOI 10.17182/hepdata.28033

The angular distribution of π + p elastic scattering has been measured at an incident momentum of 10 GeV/ c . Nearly the whole angular range was covered in one experimental set-up. The pronounced dip at − t = 2.8 (GeV/ c ) 2 , observed at lower momenta, has diminished and is essentially a shoulder at 10 GeV/ c . The other structure at larger momentum transfers are also different in detail from what we observed at 5 GeV/ c . In the 90° c.m. region the differential cross-section is approximately one nb/(GeV/ c ) 2 , which is more than two orders of magnitude lower than at 5 GeV/ c .

1 data table
Table 1

THESE DATA ARE REPORTED MORE FULLY IN C. BAGLIN ET AL., NP B98, 365 (1975).


EXCLUSIVE RHO PRODUCTION BY VIRTUAL PHOTONS

Ahrens, L.A. ; Berkelman, Karl ; Cassel, D.G. ; et al.
Phys.Rev.Lett. 42 (1979) 208, 1979.
Inspire Record 129526 DOI 10.17182/hepdata.20809

The cross section for production of ρ0 mesons has been measured in the reaction e+p→e+p+π++π−. The cross section is presented as a function of W, the c.m. energy of the virtual-photon-proton system, and -Q2, the square of the virtual-photon mass. The vector-dominance model is not able to describe the dependence of the cross section on the parameters Q2 and W. The slope parameter B describing the scattering of the proton exhibits a significant variation with Q2.

1 data table
Table 1

No description provided.


THE REACTION e p ---> e p omega0

Linnemann, J.T. ; Ahrens, L.A. ; Berkelman, Karl ; et al.
Phys.Rev.Lett. 41 (1978) 1266, 1978.
Inspire Record 129525 DOI 10.17182/hepdata.20864

The production of the ω meson by virtual photons has been measured as a function of Q2 and W. The ratio of ω production to ρ0 production is independent of Q2 in contrast to indications at lower values of W.

1 data table
Table 1

No description provided.


CROSS-SECTIONS AND POSSIBLE RESONANCES IN P ANTI-P ELECTROPRODUCTION

Gibbard, B.G. ; Ahrens, L.A. ; Berkelman, Karl ; et al.
Phys.Rev.Lett. 42 (1979) 1593-1596, 1979.
Inspire Record 146169 DOI 10.17182/hepdata.20810

The cross section for the fully constrained reaction ep→eppp¯ has been determined as a function of the electroproduction variables Q2 and s, in the range 0.7<Q2<3 GeV2 and 8<s<16 GeV2. Evidence is presented and cross-section estimates are made for resonances in the final-state p¯p system.

2 data tables
Table 1

The cross section for virtual photon are derived from E- P cross section bydividing on the virtual-photon flux factor.

Table 2

The cross section for virtual photon are derived from E- P cross section bydividing on the virtual-photon flux factor.


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.


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.


ELECTROPRODUCTION OF PI DELTA AND OTHER NONDIFFRACTIVE FINAL STATES

Day, C.T. ; Harding, D.J. ; Klinger, J.S. ; et al.
Phys.Rev.D 23 (1981) 576-586, 1981.
Inspire Record 166699 DOI 10.17182/hepdata.24078

This paper reports the results of an experiment measuring the parameters of various electroproduction reactions for a range in the electroproduction variables 0.7<Q2<4 GeV2 and 2<W2<16 GeV2. This report is limited to nondiffractive exclusive channels, with detailed results regarding the πΔ final states, statistically limited results for KΛ final states, and upper limits on the production of a number of event topologies containing a single unseen neutral particle.

16 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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