Straub, P.B.
[2.0, 5.0]
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A STUDY OF THE REACTIONS GAMMA P ---> OMEGA P AND GAMMA P ---> OMEGA DELTA+

The LAMP2 Group collaboration Barber, D.P. ; Dainton, J.B. ; Lee, L.C.Y. ; et al.
Z.Phys.C 26 (1984) 343-351, 1984.
Inspire Record 215619 DOI 10.17182/hepdata.16143

The differential and total corss sections and the decay density matrix elements have been measured for the reactions, γp→ωp and γp→ωΔ+ (1232) in the photon energy range 2.8 to 4.8 GeV. The total cross sections for ωΔ+ (1232) photo-production are found to be slightly larger than those for elastic ω photo-production in this energy range. The data are compared to the predictions of a theoretical model and the contributing exchange mechanics are discussed.

14 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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A Study of Elastic Photoproduction of Low Mass K$^{+} $K$^{-}$ Pairs From Hydrogen in the Energy Range 2.8-{GeV} to 4.8-{GeV}

Barber, D.P. ; Dainton, J.B. ; Lee, L.C.Y. ; et al.
Z.Phys.C 12 (1982) 1, 1982.
Inspire Record 168200 DOI 10.17182/hepdata.16435

The results of an experiment to study elasticK+K− photoproduction are presented. Differential cross sections and spin density matrix elements for ϕ(1.019) production are stddied as a function of incident photon energy and over a wide range of momentum transfer,t (tmin>t>−1.5(GeV/c)2). Helicity conserving amplitudes are observed to dominate ϕ production throughout this range and the differential cross sections exhibit a forward diffractive peak which cannot be understood in terms of a simple exponential dependence. A new value of the photon ϕ coupling constant is determined and shown to be consistent withe+e− annihilation measurements. A detailed study of the energy dependence of the differential cross sections is made, including other experimental data, and the extracted effective Regge trajectory compared with other diffractive processes. A study of the dependence of theK+K− decay angular distribution on invariant mass reveals evidence for ans wave contribution interfering with thep wave ϕ which may be attributable to theS* meson.

3 data tables
Table 1

LOWER LIMIT OF ABS(T) IN TABLE IS TMIN.

Table 2

No description provided.

Table 3

LOW T VARIATION WITH ELAB. LOWER LIMIT OF ABS(T) IN TABLE IS TMIN.


Hard Scattering and $\Delta - \Delta$ Exchange in Backward Photoproduction of $\Delta^{++} \pi^-$

Barber, D.P. ; Dainton, J.B. ; Lee, L.C.Y. ; et al.
Phys.Lett.B 98 (1981) 135-139, 1981.
Inspire Record 156090 DOI 10.17182/hepdata.27134

A tagged photon beam and multiparticle spectrometer have been used to measure the backward photoproduction process γp → Δ ++ π − . The energy dependence of the production cross section between 2.8 and 4.8 GeV is studied and found to exhibit shrinkage in excess of that expected for Δ σ dominance. An interpretation of the production mechanism in terms of an incoherent mixture of Δ σ exchange and a “hard scattering” contribution is presented.

1 data table
Table 1

No description provided.


Photoproduction of $\pi \Delta(1232)$ From Hydrogen in the Energy Range 2.4-{GeV} to 4.8-{GeV}

The LAMP2 Group collaboration Barber, D.P. ; Dainton, J.B. ; Lee, L.C.Y. ; et al.
Z.Phys.C 6 (1980) 93, 1980.
Inspire Record 153944 DOI 10.17182/hepdata.14328

We present differential cross sections andΔ++ spin density matrix elements for the photoproduction processγp→π−Δ++ and differential cross sections for the processγp→π+Δ0. The incident photon energy dependence is studied and a comparison is made with previous experiments and with the predictions of a theoretical model.

5 data tables
Table 1

DIFFERENTIAL CROSS SECTION AVERAGED OVER WHOLE ENERGY RANGE.

Table 2

DIFFERENTIAL CROSS SECTION AVERAGED OVER WHOLE ENERGY RANGE.

Table 3

DIFFERENTIAL CROSS SECTION FOR DIFFERENT ENERGY RANGES.

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Strangeness Exchange in the Photoproduction of $K^+ \Lambda$ (1520) Between 2.8-{GeV} and 4.8-{GeV}

Barber, D.P. ; Dainton, J.B. ; Lee, L.C.Y. ; et al.
Z.Phys.C 7 (1980) 17, 1980.
Inspire Record 153887 DOI 10.17182/hepdata.14096

A tagged photon beam (2.8

3 data tables
Table 1

FITTED CROSS SECTION ENERGY DEPENDENCE IS SIG = (6.7 +- 0.7 MUB*GEV**2) * P**(-2.1 +- 0.2), INCLUDING HIGHER ENERGY DATA.

Table 2

EXPONENTIAL SLOPE IS 6.1 +- 2.0 GEV**-2 FOR -T = 0.2 TO 0.7 GEV**2.

Table 3

No description provided.


Photoproduction of $\rho^\prime$ (1.2) and $\rho^\prime$ (1.6) in the Final States $\pi^{+} \pi^{-} \pi^{+} \pi^{-}$ and $\pi^{+} \pi^{-} \pi^0 \pi^0$

The LAMP2 Group collaboration Barber, D.P. ; Dainton, J.B. ; Lee, L.C.Y. ; et al.
Z.Phys.C 4 (1980) 169, 1980.
Inspire Record 141585 DOI 10.17182/hepdata.15607

The elastic photoproduction of four pions has been studied at incident photon energies between 2.8 and 4.8 GeV. Production cross-sections are presented and an analysis of the angular decay correlations is also described, indicating a large 1− contribution in both final states, π+ π− π+ π− and π+ π− π0 π0. A quantitative understanding of these and other available 4π photoproduction data in terms of the ρ′(∼1.2GeV) and the ρ′(∼1.6) is presented.

2 data tables
Table 1

WITH OMEGA/RHO DECAY PARAMETRIZATION.

Table 2

WITH OMEGA/A1 DECAY PARAMETRIZATION.


Charged $\rho$ Photoproduction in the Energy Range 2.8-{GeV} - 4.8-{GeV}

Barber, D.P. ; Dainton, J.B. ; Lee, L.C.Y. ; et al.
Z.Phys.C 2 (1979) 1-6, 1979.
Inspire Record 140681 DOI 10.17182/hepdata.16353

Measurements of the photoproduction processes γρ→ρ+n and γρ→ρ-Δ++ (1236) are reported in the energy range 2.8 to 4.8 GeV. The data show shrinkage of the differential cross section in this energy region for the process γρ→ρ-Δ++ (1236); no shrinkage is observed for the ρ+n process. The energy dependences of the ρ+n and ρ-Δ++ (1236) total cross sections are much steeper than current model prediction. The ρ spin density matrices for each process are also presented.

3 data tables
Table 1

No description provided.

Table 2

SLOPE AND INTERCEPT OF D(SIG)/DT.

Table 3

No description provided.


Forward and Wide Angle Elastic $\phi$ - Meson Photoproduction on Hydrogen Between 2.8-{GeV} and 4.8-{GeV}

The LAMP2 Group collaboration Barber, D.P. ; Dainton, J.B. ; Lee, L.C.Y. ; et al.
Phys.Lett.B 79 (1978) 150-156, 1978.
Inspire Record 131968 DOI 10.17182/hepdata.27382

The s and t dependence of φ (1019) photoproduction has been investigated in the incident photon energy range 2.8 to to 4.8 GeV. Differential cross-sections and density matrix elements are presented for a t range extending from t min out to −1.3 (GeV/ c ) 2 . The results are discussed in terms discussed in terms of an effective Regge trajectory in the t -channel.

5 data tables
Table 1

DIFFERENTIAL CROSS SECTIONS AVERAGED OVER TWO RANGES OF INCIDENT PHOTON ENERGY.

Table 2

VARIATION OF SMALL -T DIFFERENTIAL CROSS SECTION WITH PHOTON ENERGY.

Table 3

INTERCEPT AND SLOPE FROM FITS TO D(SIG)/DT AT SMALL -T.

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INCLUSIVE pi0 PHOTOPRODUCTION AND THE QUARK - PARTON MODEL

The LAMP2 Group collaboration Barber, D.P. ; Dainton, J.B. ; Lee, L.C.Y. ; et al.
Phys.Lett.B 77 (1978) 233-239, 1978.
Inspire Record 129937 DOI 10.17182/hepdata.27429

We present measurements on the inclusive structure function for π 0 photoproduction for the incident photon energy range of 2.8–4.8 GeV. Comparisons are made with electroproduction data and it is found that the scaling behaviour already observed for finite q 2 continues to be valid at q 2 = 0.

1 data table
Table 1

No description provided.


pi-p Two-Prong Interactions at 4.16 GeV/c

Eisner, R.L. ; Johnson, P.B. ; Klein, P.R. ; et al.
Phys.Rev. 164 (1967) 1699-1710, 1967.
Inspire Record 52292 DOI 10.17182/hepdata.26569

An analysis of π−p two-prong interactions at 4.16 GeV/c is presented. The total two-prong cross section is 19.11±0.40 mb, based on 33 672 events. The elastic-scattering differential cross section shows an exponential behavior, Kexp(−AΔ2). With A=7.36±0.14 GeV−2, the "absorption parameters" are derived as C+=0.846±0.017 and γ+=0.040±0.001. The final-state π−π0p exhibits a strong ρ−, and the π−π+n a strong ρ0 and f0. The partial cross sections for the dominant resonant channels pρ−, π−Δ+(1236) (→pπ0), ρ0n, and f0n are 0.59±0.03, 0.17±0.01, 1.15±0.05, and 0.53±0.06 mb, respectively. The ρ− production and decay angular distributions do not agree with the predictions of the absorption-modified one-pion-exchange model. However, an inclusion of the contribution from ω exchange adequately accounts for the discrepancy. The ρ0 asymmetry is interpreted as a result of an interference of the resonant P wave and isospin-zero S wave, and the corresponding spin-density matrix elements are obtained. In the final state π−p+neutrals, a clear peak for the η meson and some evidence for the ω meson are seen.

1 data table
Table 1

Axis error includes +- 0.0/0.0 contribution (?////EVENT NORMALIZATION).