Date

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 match query

DIFFERENTIAL CROSS SECTION AVERAGED OVER WHOLE ENERGY RANGE.

DIFFERENTIAL CROSS SECTION AVERAGED OVER WHOLE ENERGY RANGE.

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<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 match query

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

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

No description provided.


A Spin Parity Analysis of the $\omega \pi^0$ Enhancement Photoproduced in the Energy Range 20-{GeV} to 70-{GeV}

The Omega Photon collaboration Atkinson, M. ; Axon, T.J. ; Barberis, D. ; et al.
Nucl.Phys.B 243 (1984) 1-28, 1984.
Inspire Record 195216 DOI 10.17182/hepdata.33872

A study is made of the ωπ 0 system produced near threshold in the reaction γ p→ π + π − π 0 π 0 p. A spin-parity analysis shows that the ωπ 0 enhancement is consistent with predominant 1 + B(1235) production, with ∼20% J P = 1 − background.

2 data tables match query

MEAN BEAM ENERGY IS 39 GEV.

ESTIMATE OF B(1235) PRODUCTION CROSS SECTION ASSUMING 1+ CROSS SECTION OF 0.63 +- 0.20 MUB AND THAT 20 PCT OF THIS IS DUE TO BACKGROUND S-WAVE CONTRIBUTIONS.


Observation of a Peak at 1.28-{GeV} in the $\eta \pi \pi$ System in the Reaction $\gamma p \to \eta \pi^+ \pi^- p$

The Omega Photon collaboration Atkinson, M. ; Axon, T.J. ; Barberis, D. ; et al.
Nucl.Phys.B 242 (1984) 269-281, 1984.
Inspire Record 194474 DOI 10.17182/hepdata.33873

A peak is reported in the ηπ + π − system, produced in the reaction γ p→ ηπ + π − p, at a mass of 1.28 ± 0.01 GeV with a width of 0.08 ± 0.02 GeV. Possible spin-parity assignments for the peak are shown to be J π = 1 − , J π = 1 + or J π = 2 + and interpretations of these assignments are discussed.

2 data tables match query

No description provided.

No description provided.


The Reaction $\gamma p \to p \omega \pi^+ \pi^-$ for Photon Energies of 25-{GeV} - 50-{GeV}

The Omega Photon collaboration Atkinson, M. ; Axon, T.J. ; Barberis, D. ; et al.
Nucl.Phys.B 229 (1983) 269-283, 1983.
Inspire Record 189045 DOI 10.17182/hepdata.33921

Measurements of the reaction γ p → p ωπ + π − are reported for photon energies 25–50 GeV. Particular attention is paid to ωπ + π − masses < 2 GeV. A search is made for ω′ or φ′ partners of the ϱ′(1600). Evidence is presented against the existence of narrow states and against the production of a broad state by an s -channel helicity conserving mechanism.

1 data table match query

No description provided.


Photoproduction of $K \bar{K} \pi$ Final States in the Photon Energy Range From 20-{GeV} to 70-{GeV}

The Omega Photon collaboration Atkinson, M. ; Axon, T.J. ; Barberis, D. ; et al.
Nucl.Phys.B 231 (1984) 1-14, 1984.
Inspire Record 191239 DOI 10.17182/hepdata.33920

The reactions γ p→K + K − π 0 (p) and γ p→ K s 0 K ± π ± (p) have been measured using tagged photons in the energy range 20 to 70 GeV. No resonance structure is observed in either of the K K π invariant mass distributions, which range from threshold up to ∼ 3 GeV. The photoproduction cross sections for φπ 0 and K ∗ (892)K are presented and are compared with theoretical predictions. No evidence has been found for the photoproduction of φ′ (1680).

2 data tables match query

No description provided.

NO EVIDENCE FOR RESONANT STRUCTURE AT PHIPRIME(1680).


Photoproduction of $\pi^+ \pi^- \pi^0$ on Hydrogen With Linearly Polarized Photons of Energy 20-{GeV} - 70-{GeV}

The Omega Photon & Bonn-CERN-Glasgow-Lancaster-Manchester-Paris-Rutherford-Sheffield collaborations Atkinson, M. ; Axon, T.J. ; Barberis, D. ; et al.
Nucl.Phys.B 231 (1984) 15-39, 1984.
Inspire Record 191169 DOI 10.17182/hepdata.33892

Results on photoproduction of π + π − π 0 in the photon energy range 20–70 GeV are presented. For the ω meson, the production cross-section is found to be 1010±15 (statistical)±290 (systematic) nb and is constant over the incident photon energy range. Spin-density matrix elements are evaluated for ω meson production. The φ meson is observed with a total photoproduction cross section (corrected for branching ratio to π + π − π 0 ) of 610±35±170 nb. A third resonance, at 1.67 GeV, is seen in the mass spectrum and its interpretation is discussed. The production of a broad π + π − π 0 continuum, mainly via ϱπ, and peaking at 1.2 GeV, contributes with a cross section of about 2.5 ωb. The spin-parity content is analysed by the moments of the π + π − π 0 decay angular distribution in the helicity frame and by maximum likelihood fits to the π + π − π 0 Dalitz plot. It is found that production of J P = 1 − states accounts for less than half of the total mass spectrum above 900 MeV. There is a broad enhancement in the 1 + wave around 1.15 GeV indicating photoproduction of the H(1190) meson.

6 data tables match query

No description provided.

EXPONENTIAL FITS TO D(SIG)/DT IN OMEGA MASS REGION.

EXPONENTIAL FITS TO D(SIG)/DT OVER FULL ENERGY FOR THREE MASS REGIONS CORRESPONDING TO OMEGA, PHI AND OMEGA*.

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Inclusive Production of Lambdas and Anti-lambdas in $\gamma p$ Interactions for Photon Energies Between 25-{GeV} and 70-{GeV}

The Bonn-CERN-Ecole Poly-Glasgow-Lancaster-Manchester-Orsay-Paris-Rutherford-Sheffield collaboration Aston, D. ; Atkinson, M. ; Bailey, R. ; et al.
Nucl.Phys.B 195 (1982) 189-202, 1982.
Inspire Record 167734 DOI 10.17182/hepdata.34176

Results are presented on the inclusive photoproduction of λ and λ for incident photon energies between 25 and 70 GeV. The slope parameter of the p T 2 distribution is found to be 2.83±0.1 GeV −2 for λ and 3.28±0.25 GeV −2 for λ . The x F distributions, measured in the range −0.2 to 0.7, show that while λ are produced centrally, λ production extends to more negative values of x F ; the shapes show no energy dependence and are similar to those in pion-induced reactions. The polarization of the produced λ is less than 10%. The results are discussed in terms of vector dominance and quark fusion models.

4 data tables match query

No description provided.

No description provided.

No description provided.

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The total photon-proton cross-section for hadron production

Armstrong, T.A. ; Hogg, W.R. ; Lewis, G.M. ; et al.
Phys.Lett.B 34 (1971) 535-538, 1971.
Inspire Record 69289 DOI 10.17182/hepdata.28520

The total hadronic cross section, σ T has been measured for tagged γ -rays, using electron beams in the GeV range, and narrow energy bins. Preliminary data are given covering the γ -energy region 275 MeV-1850 MeV, where interesting structure characteristics are observed.

1 data table match query

No description provided.


The Reaction $\gamma p \to p \pi^+ \pi^- \pi^+ \pi^-$ for Photon Energies From 25-{GeV} to 70-{GeV}

The Bonn-CERN-Ecole Poly-Glasgow-Lancaster-Manchester-Orsay-Paris-Rutherford-Sheffield collaboration Aston, D. ; Atkinson, M. ; Bailey, R. ; et al.
Nucl.Phys.B 189 (1981) 15-39, 1981.
Inspire Record 164533 DOI 10.17182/hepdata.34258

Measurements of the reaction γ p → p π + π − π + π − are presented, in which π + π − π + π − systems with masses up to 3 GeV are produced from fragmentation of the incident photon. The reaction is dominated by production of the large peak of the ϱ′(1600) meson and, at higher masses ≳2 GeV, y production of jet-like 4 π systems. The ϱ′(1600) meson is produced by a predominantly s -channel helicity conserving mechanism. At higher masses there are also indications of ϱπ peaks, of masses 1.3 GeV (the A 2 meson) and 1.75 GeV, produced with a recoiling π meson by a mechanism consistent with the Deck effect.

1 data table match query

CORRECTED FOR TAILS OF BREIT-WIGNER RESONANCE USED IN FIT AND ALLOWING FOR 10 PCT BACKGROUND.