Barber, D.P.
Photoproduction
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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<Eγ<4.8 GeV) and multiparticle spectrometer have been used to study the photoproduction in hydrogen ofK+Λ(1520). Precise values for the mass and width of the Λ(1520) are given. The total cross-section is found to fall with increasing photon energy like (6.5±0.7)Eγ−(2.1±0.2) μb. The differential cross sectiondσ/dt indicates peripheral forward production and exhibits no evidence for shrinkage when compared with higher energy data. The Λ(1520) spin density matrix shows thatK exchange alone cannot account for the production mechanism. The reaction is found to resemble the process γp→K+ Λ(1115) in all measurable respects.

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 $\pi \Delta(1232)$ 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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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.


Cascade production in the reactions gamma p --> K+ K+ (X) and gamma p --> K^+ K^+ pi- (X)

Guo, L. ; Weygand, D.P. ; Battaglieri, M. ; et al.
Phys.Rev.C 76 (2007) 025208, 2007.
Inspire Record 744487 DOI 10.17182/hepdata.31494

Photoproduction of the cascade resonances has been investigated in the reactions $\gamma p \to K^+ K^+ (X)$ and $\gamma p \to K^+ K^+ \pi^- (X)$. The mass split of the $\Xi$ doublet is measured to be $5.4\pm 1.8$ MeV/c$^2$, consistent with existing measurements. The differential (total) cross sections for the $\Xi^{-}$ have been determined for photon beam energies from 2.75 to 3.85 (4.75) GeV, and are consistent with a possible production mechanism of $Y^*\to K^+\Xi^-$ through a $t$-channel process. The reaction $\gamma p \to K^+ K^+ \pi^-[\Xi^0]$ has also been investigated in search of excited cascade resonances. No significant signal of excited cascade states other than the $\Xi^-(1530)$ is observed. The cross section results of the $\Xi^-(1530)$ have also been obtained for photon beam energies from 3.35 to 4.75 GeV.

47 data tables
Table 1

Differential cross section for XI- production as a function of the invariant mass of the XI- with either of the K+ mesons for incident photon energy 2.79 Gev.

Table 2

Differential cross section for XI- production as a function of the invariant mass of the XI- with either of the K+ mesons for incident photon energy 2.89 Gev.

Table 3

Differential cross section for XI- production as a function of the invariant mass of the XI- with either of the K+ mesons for incident photon energy 2.99 Gev.

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Proton anti-proton pair production in two photon collisions at LEP

The L3 collaboration Achard, P. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 571 (2003) 11-20, 2003.
Inspire Record 620433 DOI 10.17182/hepdata.48883

The reaction e^+e^- -> e^+e^- proton antiproton is studied with the L3 detector at LEP. The analysis is based on data collected at e^+e^- center-of-mass energies from 183 GeV to 209 GeV, corresponding to an integrated luminosity of 667 pb^-1. The gamma gamma -> proton antiproton differential cross section is measured in the range of the two-photon center-of-mass energy from 2.1 GeV to 4.5 GeV. The results are compared to the predictions of the three-quark and quark-diquark models.

4 data tables
Table 1

Total cross section for P PBAR production at a mean centre-of-mass energy of 197 GeV.

Table 2

The cross section as a function of W for ABS(COS(THETA)) < 0.6.

Table 3

The differential cross section as a function of COS(THETA*) for three W ranges.

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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 $\rho^\prime$ (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.


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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