64 results on '"G.R. Brookes"'
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2. Photoproduction of final states in the photon energy range from 20 to 70 GeV
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C. Paterson, R. E. Hughes-Jones, J. B. Lane, P. S. Flower, H. Rotscheidt, R. J. Ellison, T. J. Axon, Markus Atkinson, Klaus Heinloth, J. V. Morris, R. J. Thompson, C. Raine, J. A. G. Morris, B. Diekmann, A. P. Waite, D. Mercer, M. Ibbotson, H.-P. Jakob, J. Laberrigue, P. Flynn, M. A. R. Kemp, W. Galbraith, A. Schlösser, B. Dickinson, Kevin M. Smith, J. M. Levy, T. J. Brodbeck, Richard McClatchey, J. B. Dainton, Julian Bunn, V. Liebenau, D. Barberis, M. Davenport, G.R. Brookes, Ch De La Vaissière, A. B. Clegg, G. N. Patrick, P. Sharp, A. Donnachie, G. D. Lafferty, M. Jung, M. F. Worsell, J. S. Hutton, P. J. Bussey, T. P. Yiou, D. Newton, B. R. Kumar, I. O. Skillicorn, E. Paul, R. C. W. Henderson, K. M. Storr, J. C. Lassalle, and M. Reidenbach
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Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Pair production ,Pion ,Meson ,Antimatter ,Hadron ,Invariant mass ,Photon energy ,Nucleon - Abstract
The reactions γp→K+K−π0(p) and γp→ Ks0K± 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 KKπ invariant mass distributions, which range from threshold up to ∼ 3 GeV. The photoproduction cross sections for φπ0 and K∗(892)K are presented and are compared with theoretical predictions. No evidence has been found for the photoproduction of φ′ (1680).
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- 1984
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3. Elastic antiproton-proton photoproduction between threshold and 4.8 GeV
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L. C. Y. Lee, J. B. Dainton, P.B. Wilkes, G. N. Patrick, G. Frost, T. J. Sloan, D. Newton, G.F. Pearce, R. Marshall, D.T. Williams, G.R. Brookes, W. J. Haynes, J.C. Thompson, D.P. Barber, and T. J. Brodbeck
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Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Cross section (physics) ,Particle physics ,Spectrometer ,Meson ,Proton ,Antiproton ,Mass spectrum ,High Energy Physics::Experiment ,Photon beam ,Nuclear Experiment - Abstract
The cross section for the process γ p → p pp has been measured from threshold up to 4.8 GeV using a tagged photon beam and a multiparticle spectrometer which detected all final state particles. The production cross section rises rapidly from threshold to a constant value of 35 nb. No evidence is found in the mass spectra for the production of narrow meson resonances decaying into p p .
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- 1980
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4. Search forΔI=2Electromagnetic Currents in Pion Photoproduction
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L.S. Littenberg, G.R. Brookes, R.W. Clifft, S.E. Rock, J.C. Thompson, R. Marshall, D.L. Ward, and E. Gabathuler
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Physics ,Particle physics ,Pion ,General Physics and Astronomy - Published
- 1974
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5. The reaction γp → pωπ+π− for photon energies of 25–50 GeV
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P. Flynn, C. Paterson, R. E. Hughes-Jones, J. B. Dainton, R. J. Ellison, T. J. Axon, C. Raine, A. B. Clegg, Kevin M. Smith, H. Rotscheidt, J. B. Lane, E. Paul, J. S. Hutton, G. N. Patrick, P. Sharp, J. A. G. Morris, A. Donnachie, H.-P. Jakob, A. Schlösser, A. P. Waite, Richard McClatchey, J. C. Lassalle, M. F. Worsell, G.R. Brookes, M. Ibbotson, J. M. Levy, G. D. Lafferty, R. C. W. Henderson, D. Mercer, J. V. Morris, M. Reidenbach, B. R. Kumar, M. A. R. Kemp, I. O. Skillicorn, P. J. Bussey, R. J. Thompson, T. J. Brodbeck, K. M. Storr, W. Galbraith, Julian Bunn, D. Barberis, B. Dickinson, V. Liebenau, M. Davenport, Ch De La Vaissière, T. P. Yiou, D. Newton, Markus Atkinson, B. Diekmann, J. Laberrigue, M. Jung, P. S. Flower, and Klaus Heinloth
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Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Particle physics ,Photon ,Helicity - Abstract
Measurements of the reaction γp → pωπ+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.
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- 1983
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6. Evidence for a high mass enhancement in K+K− photoproduction
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G. London, Markus Atkinson, D. Mercer, Austin Ball, J. Bröring, C. Steinhauer, A. Rougé, B. Bouquet, G. De Rosny, F. Richard, Ch De La Vaissière, C. Reine, B. D'Almagne, R. E. Hughes-Jones, Y. Pons, A. Donnachie, H. Videau, J.B. Lane, J. Six, R.T. Thompson, M. Sené, P. Feller, J.C. Sleeman, D. Ezra, P.G. Hampson, E. Paul, K.M. Storr, W. Wojcik, I.P. Duerdoth, J. P. Dufey, James H. Roberts, J. M. Levy, G.R. Brookes, A. Ferrer, Pierre Petroff, Kevin M. Smith, M. Goldberg, M. Górski, B. Grossetete, M. Jung, V. Liebenau, I. O. Skillicorn, M.A.R. Kemp, B. Drevillon, J.V. Morris, S. Goodman, J.S. Hutton, T.P. Yiou, I. Videau, W. Graves, A. Wijangco, B. Diekmann, J. Litt, M. Draper, K. Heinloth, W. Galbraith, P. J. Bussey, Daniel Treille, R. Bailey, P. Roudeau, D. Newton, B.R. Kumar, S. Katsanevas, R. George, D. Aston, R. Richter, G. D. Lafferty, S.D.M. Gill, D. Clarke, J.-P. Wuthrick, K. Müller, F. Friese, P.H. Flynn, F. Kovacs, A. B. Clegg, M. Rumpf, M. Ibbotson, R.J. Ellison, and A.P. Waite
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Mass enhancement ,Physics ,Nuclear and High Energy Physics ,Range (particle radiation) ,Photon ,Analytical chemistry ,Atomic physics - Abstract
The reaction γ p → K + K − p has been investigated with tagged photons in the energy range of 20 E γ
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- 1981
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7. Hard scattering and Δσ exchange in backward photoproduction of Δ++π−
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T. J. Brodbeck, L. C. Y. Lee, P.B. Wilkes, D.P. Barber, G. Frost, G.F. Pearce, J. B. Dainton, J.C. Thompson, R. Marshall, G.R. Brookes, D.T. Williams, T. J. Sloan, W. J. Haynes, G. N. Patrick, and D. Newton
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Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Cross section (physics) ,Spectrometer ,Scattering ,Photon beam ,Atomic physics ,Measure (mathematics) - Abstract
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.
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- 1981
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8. Photon diffractive dissociation to ρρπ and ρπππ states
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Julian Bunn, D. Barberis, E. Paul, C. Raine, R. J. Thompson, M. Ibbotson, D. Mercer, J. A. G. Morris, M. Davenport, Ch De La Vaissière, T. P. Yiou, P. J. Flynn, Richard McClatchey, V. Lienau, G.R. Brookes, T. J. Brodbeck, M. Atkinson, J. C. Lassalle, J. S. Hutton, B. R. Kumar, I. O. Skillicorn, D. Newton, C. Paterson, A. Schlösser, R. E. Hughes-Jones, W. Galbraith, R. C. W. Henderson, P. S. Flower, H.-P. Jakob, A. Donnachie, Klaus Heinloth, B. Dickinson, J. B. Lane, J. B. Dainton, R. J. Ellison, T. J. Axon, M. F. Worsell, M. Jung, H. Rotscheidt, P. Sharp, P. J. Bussey, J. V. Morris, G. D. Lafferty, M. Reidenbach, B. Diekmann, K. M. Storr, J. Laberrigue, A. B. Clegg, G. N. Patrick, A. P. Waite, Kevin M. Smith, and J. M. Levy
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Physics ,Photon ,Physics and Astronomy (miscellaneous) ,010308 nuclear & particles physics ,Interaction model ,Vector meson dominance ,01 natural sciences ,Omega ,Dissociation (chemistry) ,Nuclear physics ,0103 physical sciences ,Mass spectrum ,Atomic physics ,010306 general physics ,Engineering (miscellaneous) - Abstract
This paper reports studies of the reactions γp→ρ π π πp and γp→ρ ρ πp. In particular a peak is reported in the ρ ρ π mass spectrum with closely similar mass and width to those of the ω ρ π peak previously reported in the reaction γp→ω ρ πp. The ratio of production cross sections is found to be ρ ρ π/ω ρ π=0.96±0.19, in serious disagreement with the expectation from Vector Meson Dominance. A possible explanation is indicated.
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- 1988
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9. A study of elastic photoproduction of low massK + K ? pairs from hydrogen in the energy range 2.8?4.8 GeV
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G.F. Pearce, J. B. Dainton, D.T. Williams, L. C. Y. Lee, G. Frost, J.C. Thompson, D.P. Barber, P.B. Wilkes, T. J. Sloan, T. J. Brodbeck, R. Marshall, W. J. Haynes, D. Newton, G.R. Brookes, and G. N. Patrick
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Momentum ,Physics ,Coupling constant ,Annihilation ,Photon ,Physics and Astronomy (miscellaneous) ,Meson ,Invariant mass ,Photon energy ,Atomic physics ,Engineering (miscellaneous) ,Helicity - Abstract
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 (t min >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.
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- 1982
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10. Forward and wide angle elastic φ-meson photoproduction on hydrogen between 2.8 and 4.8 GeV
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J. B. Dainton, L. C. Y. Lee, P.B. Wilkes, D.P. Barber, W. J. Haynes, G. N. Patrick, T. J. Sloan, J.C. Thompson, R. Marshall, T. J. Brodbeck, G.F. Pearce, D.T. Williams, D. Newton, G. Frost, and G.R. Brookes
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Density matrix ,Physics ,Nuclear and High Energy Physics ,Particle physics ,Range (particle radiation) ,Meson ,Hydrogen ,chemistry ,chemistry.chemical_element ,High Energy Physics::Experiment ,Photon energy ,Nuclear Experiment - Abstract
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.
- Published
- 1978
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11. Observation of a peak at 1.28 GeV in the {ce:inline-formula}ηππ{/ce:inline-formula} system in the reaction {ce:inline-formula}γp π+π-p{/ce:inline-formula}
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H.-P. Jakob, Markus Atkinson, J. V. Morris, B. R. Kumar, I. O. Skillicorn, Kevin M. Smith, G. D. Lafferty, B. Diekmann, P. S. Flower, J. Laberrigue, J. A. G. Morris, D. Newton, J. S. Hutton, C. Paterson, J. C. Lassalle, M. Ibbotson, J. B. Lane, W. Galbraith, R. E. Hughes-Jones, Klaus Heinloth, D. Mercer, T. J. Brodbeck, M. Jung, J. M. Levy, M. Reidenbach, Julian Bunn, R. J. Ellison, T. J. Axon, E. Paul, D. Barberis, R. C. W. Henderson, K. M. Storr, A. Donnachie, M. F. Worsell, P. J. Bussey, Richard McClatchey, G.R. Brookes, T. P. Yiou, A. Schlösser, R. J. Thompson, A. P. Waite, A. B. Clegg, H. Rotscheidt, G. N. Patrick, P. Sharp, C. Raine, P. Flynn, J. B. Dainton, B. Dickinson, V. Liebenau, M. Davenport, and Ch De La Vaissière
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Nuclear physics ,Physics ,Nuclear and High Energy Physics ,TheoryofComputation_MATHEMATICALLOGICANDFORMALLANGUAGES ,Data_FILES ,lcsh:QC770-798 ,lcsh:Nuclear and particle physics. Atomic energy. Radioactivity ,Software_PROGRAMMINGLANGUAGES ,Omega - Abstract
A peak is reported in the {ce:inline-formula}ηπ +π-{/ce:inline-formula} system, produced in the reaction {ce:inline-formula}γp ηπ +π -p{/ce:inline-formula}, at a mass of {ce:inline-formula}1.28 ± 0.01GeV{/ce:inline-formula} with a width of {ce:inline-formula}0.08 ± 0.02GeV{/ce:inline-formula}. Possible spin-parity assignments for the peak are shown to be {ce:inline-formula}J π = 1 -, J π = 1 +orJ π = 2 +{/ce:inline-formula} and interpretations of these assignments are discussed.
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- 1984
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12. Inclusive π0 photoproduction and the quark-parton model
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D.P. Barber, L. C. Y. Lee, G. Frost, G.R. Brookes, J.C. Thompson, J. B. Dainton, W. J. Haynes, R. Marshall, A.M. Osborne, T. J. Brodbeck, G. N. Patrick, T. J. Sloan, G.F. Pearce, D.T. Williams, and P.B. Wilkes
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Nuclear physics ,Quark ,Physics ,Nuclear and High Energy Physics ,Particle physics ,Range (particle radiation) ,Structure function ,Parton ,Photon energy ,Scaling - Abstract
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.
- Published
- 1978
- Full Text
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13. Diffractive photoproduction of ab 1π system
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J. S. Hutton, C. Paterson, J. C. Lassalle, P. S. Flower, M. Reidenbach, R. E. Hughes-Jones, Julian Bunn, D. Barberis, A. Schlösser, J. V. Morris, Klaus Heinloth, H.-P. Jakob, R. J. Ellison, T. J. Axon, B. Diekmann, Kevin M. Smith, E. Paul, J. Laberrigue, R. C. W. Henderson, M. Ibbotson, K. M. Storr, J. A. G. Morris, G. D. Lafferty, Richard McClatchey, C. Raine, R. J. Thompson, G.R. Brookes, B. R. Kumar, I. O. Skillicorn, H. Rotscheidt, D. Mercer, P. J. Bussey, W. Galbraith, A. P. Waite, T. J. Brodbeck, M. F. Worsell, J. B. Dainton, M. Atkinson, M. Jung, T. P. Yiou, A. Donnachie, D. Newton, A. B. Clegg, G. N. Patrick, B. Dickinson, V. Liebenau, M. Davenport, Ch De La Vaissière, J. M. Levy, P. J. Flynn, P. Sharp, and J. B. Lane
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Physics ,Mass enhancement ,Nuclear physics ,Particle physics ,Physics and Astronomy (miscellaneous) ,Pi system ,Mass spectrum ,Production (computer science) ,Engineering (miscellaneous) ,Omega ,Bar (unit) - Abstract
It is shown that a likely interpretation of theb1± π∓ mass spectrum from diffractive photoproduction is that it is due to contributions from the ω3(1670), in accord with corresponding production of the ρ3(1690), and from a further peak with a mass of 1.88±0.04 GeV and a width ≦0.3 GeV. The possibility that this latter peak can be due to a group of\(q\bar qg\) hybrid states, as proposed by Isgur and Paton, is explored.
- Published
- 1987
- Full Text
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14. Observation of a threshold enhancement in the reaction γp→K+K−π+π−p at γ energies of 20–70 GeV
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R. E. Hughes-Jones, J.S. Hutton, V. Liebenau, H. Videau, G.R. Brookes, J.B. Lane, P. Roudeau, J. M. Levy, James H. Roberts, Kevin M. Smith, P.J. Flynn, A. Rougé, J. Litt, C. Steinhauer, K.M. Storr, S.D.M. Gill, M. Rumpf, I. Videau, M. Goldberg, W. Graves, I. O. Skillicorn, K. Müller, D. Mercer, F. Kovacs, R. Bailey, G. De Rosny, Daniel Treille, Austin Ball, J. Bröring, K. Heinloth, W. Galbraith, M.A.R. Kemp, M. Draper, B.R. Kumar, B. Drevillon, C. Raine, F. Richard, Markus Atkinson, P.G. Hampson, J.V. Morris, S. Goodman, R. George, M. Jung, G. D. Lafferty, D. Newton, A. Wijangco, B. Bouquet, A. B. Clegg, J.-P. Wuthrick, E. Paul, A.P. Waite, T.P. Yiou, P. J. Bussey, B. D'Almagne, S. Katsanevas, R.J. Ellison, D. Aston, R. Richter, J.C. Sleeman, Ch De La Vaissière, M. Ibbotson, D. Ezra, F. Friese, Pierre Petroff, I.P. Duerdoth, M. Sené, P. Feller, B. Diekmann, Y. Pons, B. Grossetete, G. London, W. Wojcik, A. Ferrer, J. P. Dufey, D. Clarke, and J. Six
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Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Channel (broadcasting) ,Atomic physics - Abstract
An analysis is presented of the channel γp→K + K − π + π − p. Evidence is found for a K + Kπ enhancement of mass ≈1.9 GeV and width ≈0.4 GeV. The spin-parity of the enhancement is consistent with being 1 − .
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- 1980
- Full Text
- View/download PDF
15. A 480-channel lead glass Cherenkov detector
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P.N. Johnson, J.C. Thompson, G.F. Pearce, D.T. Williams, J. B. Dainton, G.R. Brookes, T. J. Sloan, W. Smith, D.W.L. Tolfree, R. Marshall, G. Frost, L.S. Littenberg, G. N. Patrick, J.D.B. Rees, P.B. Wilkes, D. Newton, T. J. Brodbeck, L. C. Y. Lee, E. Gabathuler, D.P. Barber, and A.M. Osborne
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Physics ,Range (particle radiation) ,Photon ,Physics::Instrumentation and Detectors ,Cherenkov detector ,business.industry ,Astrophysics::High Energy Astrophysical Phenomena ,Detector ,General Medicine ,Electron ,law.invention ,Nuclear physics ,Lead glass ,Optics ,law ,visual_art ,visual_art.visual_art_medium ,High Energy Physics::Experiment ,business ,Absorption (electromagnetic radiation) ,Cherenkov radiation - Abstract
The essential features, constructional details and performance of a 480-channel detector of lead glass total absorption Cherenkov counters are described. Results are presented on the linearity, energy and spatial resolution for electrons and photons in the energy range up to 4.8 GeV. The behaviour of charged hadrons in the detector is also described.
- Published
- 1977
- Full Text
- View/download PDF
16. Study ofηπ+π− in the ϱ′(1600) mass region photoproduced in the reaction γp→ηπ+π− p at photon energies of 20 to 70 GeV
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P. J. Bussey, R. E. Hughes-Jones, J. V. Morris, Julian Bunn, R. J. Ellison, T. J. Axon, H.-P. Jakob, D. Barberis, B. R. Kumar, I. O. Skillicorn, Kevin M. Smith, H. Rotscheidt, C. Paterson, W. Galbraith, D. Newton, J. M. Levy, M. Ibbotson, A. Donnachie, G. D. Lafferty, B. Dickinson, J. C. Lassalle, A. Schlösser, T. J. Brodbeck, M. Reidenbach, M. F. Worsell, C. Raine, V. Liebenau, J. S. Hutton, E. Paul, T. P. Yiou, M. Davenport, R. C. W. Henderson, Ch De La Vaissière, D. Mercer, R. J. Thompson, A. P. Waite, K. M. Storr, J. B. Dainton, A. B. Clegg, G. N. Patrick, P. Sharp, H. Marsiske, J. B. Lane, P. J. Flynn, P. S. Flower, Klaus Heinloth, M. Jung, B. Diekmann, J. Laberrigue, Markus Atkinson, J. A. G. Morris, Richard McClatchey, and G.R. Brookes
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Physics ,Nuclear physics ,Photon ,Angular distribution ,Physics and Astronomy (miscellaneous) ,Branching fraction ,Elementary particle ,Photon energy ,Quantum field theory ,Engineering (miscellaneous) ,Omega - Abstract
In diffractive photoproduction ofηπ+π−, the two-body substatesηρ0 andA 2π are found to contribute significantly to the cross-section forηπ+π− masses below 2.4 GeV. From a spin-parity analysis the branching ratio, ρ′(1600)→ηρ/ρ′(1600)→, is determined to be
- Published
- 1986
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17. A high resolution photon tagging system in the GeV region
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D.W.L. Tolfree, C. Shiel, W.R. Rawlinson, G.R. Brookes, and E. Gabathuler
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Physics ,Range (particle radiation) ,Electron energy ,Photon ,Nuclear Theory ,Resolution (electron density) ,Bremsstrahlung ,Physics::Optics ,General Medicine ,Photon energy ,Nuclear physics ,Cathode ray ,Physics::Accelerator Physics ,Atomic physics ,Nuclear Experiment ,Energy (signal processing) - Abstract
A photon tagging system which measures the energy of photons in a bremsstrahlung spectrum is described. The apparatus covers a photon energy range of 2 GeV starting 160 MeV below the energy of the incident electron beam. 192 counters provide a nominal resolution between 6 MeV for a photon energy 160 MeV below the incident electron energy and 11 MeV for a photon energy 2160 MeV below the incident electron energy.
- Published
- 1974
- Full Text
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18. A large aperture spectrometer for the study of multibody photoproduction in the incident energy range 1–5 GeV
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G.F. Pearce, D.T. Williams, G. Frost, A.M. Osborne, G. N. Patrick, M. Edward, J. B. Dainton, T. J. Brodbeck, J.D.B. Rees, L. C. Y. Lee, W. J. Haynes, T. J. Sloan, D. Newton, P.B. Wilkes, E. Gabathuler, D.P. Barber, J.C. Thompson, G.R. Brookes, M. Sproston, and R. Marshall
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Physics ,Nuclear physics ,Range (particle radiation) ,Data acquisition ,Spectrometer ,Magnet ,Incident energy ,General Medicine ,Kinematics ,Large aperture ,Event reconstruction - Abstract
A large aperture magnet spectrometer (LAMP 2) is described which was used in a tagged photon beam to collect 1.5 x 10 7 triggers from photoproduction processes in hydrogen. The techniques employed for the data acquisition and subsequent event reconstruction and kinematic identification are described and evaluated.
- Published
- 1978
- Full Text
- View/download PDF
19. Search for a ϕ′ vector meson in diffractive photoproduction ofK + K −π+π−
- Author
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Kevin M. Smith, R. E. Hughes-Jones, R. J. Ellison, T. J. Axon, W. Galbraith, J. S. Hutton, J. C. Lassalle, J. B. Lane, P. J. Bussey, Julian Bunn, G. N. Patrick, H.-P. Jakob, J. A. G. Morris, B. R. Kumar, I. O. Skillicorn, D. Barberis, H. Rotscheidt, G. D. Lafferty, Markus Atkinson, A. Donnachie, T. P. Yiou, M. Ibbotson, Richard McClatchey, D. Newton, G.R. Brookes, A. B. Clegg, M. Reidenbach, C. Paterson, E. Paul, P. Sharp, P. S. Flower, T. J. Brodbeck, R. C. W. Henderson, Klaus Heinloth, A. P. Waite, M. Davenport, Ch De La Vaissière, J. V. Morris, J. M. Levy, K. M. Storr, B. Diekmann, B. Dickinson, J. Laberrigue, V. Liebenau, P. J. Flynn, M. Jung, A. Schlösser, C. Raine, R. J. Thompson, J. B. Dainton, M. F. Worsell, D. Mercer, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
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Physics ,Nuclear physics ,Particle physics ,Physics and Astronomy (miscellaneous) ,010308 nuclear & particles physics ,Component (thermodynamics) ,0103 physical sciences ,Vector meson ,010306 general physics ,01 natural sciences ,Engineering (miscellaneous) ,Particle Physics - Experiment ,Communication channel - Abstract
A study of photoproduction ofK+K−π+π− shows a broad threshold enhancement, about 30% of which is due toK*Kπ production. ThisK*Kπ component shows no dynamical features indicative of the existence of a ϕ′ vector meson in this channel.
- Published
- 1986
- Full Text
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20. MICROSIM as a teaching aid
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A.J. Cowling and G.R. Brookes
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Engineering drawing ,Engineering ,Microprocessor ,Software ,Computer engineering ,business.industry ,law ,Microcomputer ,General Engineering ,business ,law.invention - Abstract
The MICROSIM system was produced originally as a tool for developing microprocessor software, but it can also be used as an aid to teaching assembly-language programming for microprocessors. This paper describes some modifications that have been made to the system to make it more suitable for teaching, and discusses its advantages and disadvantages as compared to the use of conventional microcomputer systems.
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- 1983
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21. A multi-user microprocessor system used for teaching
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G.R. Brookes, G.A. Manson, and A.J. Cowling
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Microprocessor system ,business.industry ,Student teaching ,Computer science ,Embedded system ,General Engineering ,Concurrent computing ,business ,Multi-user - Abstract
A multi-user processor system has been in use for student teaching. It is based on the CP/M∗ compatible operating system McNOS. The experience of its use and possible limitations are described in the light of providing a cost effective reliable alternative to single user microprocessors with the additional benefit of utilization for teaching concurrent programming techniques.
- Published
- 1984
- Full Text
- View/download PDF
22. The reactions γp→ωπ+π−p and γp→ηπ+π−p at photon energies of 25–70 GeV
- Author
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J. P. Dufey, D. Clarke, G. De Rosny, A. B. Clegg, B. D'Almagne, J. Six, R. E. Hughes-Jones, D. Aston, R. Richter, Daniel Treille, V. Liebenau, P.G. Hampson, D. Ezra, A. Rougé, J. Litt, B. Diekmann, M. Goldberg, H. Videau, K.M. Storr, D. Mercer, J.B. Lane, W. Wojcik, B. Drevillon, P.J. Flynn, F. Kovacs, A. Ferrer, F. Friese, K. Müller, R. J. Thompson, J.C. Sleeman, A. Wijangco, J.V. Morris, M.A.R. Kemp, D. Newton, P. J. Bussey, J. M. Levy, P. Feller, F. Richard, G. London, G.R. Brookes, J.S. Hutton, M. Draper, E. Paul, M. Rumpf, B.R. Kumar, R. Bailey, I. O. Skillicorn, S.D.M. Gill, Kevin M. Smith, G. D. Lafferty, C. Steinhauer, P. Roudeau, S. Goodman, C. Raine, R. George, J.-P. Wuthrick, B. Grossetete, A.P. Waite, R.J. Ellison, S. Katsanevas, M. Sené, M. Ibbotson, Ch De La Vaissière, Y. Pons, I. Videau, W. Graves, I.P. Duerdoth, M. Jung, K. Heinloth, W. Galbraith, T.P. Yiou, James H. Roberts, Austin Ball, J. Bröring, Markus Atkinson, B. Bouquet, and Pierre Petroff
- Subjects
Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Angular momentum ,Particle physics ,Photon - Abstract
Measurements of ω and η production in the reaction γp→π+π−π+π−π0p are presented, showihg that the ωπ+π− channel is made up of an enhancement at ∼1.7 GeV of width ∼0.5 GeV, which is consistent with being a 1− state, together with a distribution at higher masses containing higher angular momentum terms. The ηπ+π− final state is produced with a similar cross section and also shows a low-mass enhancement.
- Published
- 1980
- Full Text
- View/download PDF
23. Evidence for a ωϱ±π± state in diffractive photoproduction
- Author
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A. B. Clegg, M. Reidenbach, Markus Atkinson, E. Paul, G. N. Patrick, P. Sharp, C. Paterson, R. C. W. Henderson, A. P. Waite, Richard McClatchey, G.R. Brookes, P. S. Flower, Kevin M. Smith, K. M. Storr, B. Diekmann, J. B. Lane, J. Laberrigue, D. Barberis, Klaus Heinloth, J. S. Hutton, J. V. Morris, D. Newton, R. E. Hughes-Jones, J. C. Lassalle, B. Dickinson, M. Jung, M. Ibbotson, W. Galbraith, J. A. G. Morris, H. Rotscheidt, V. Liebenau, Julian Bunn, R. J. Ellison, H.-P. Jakob, T. J. Axon, T. J. Brodbeck, M. Davenport, P. J. Flynn, Ch De La Vaissière, B. R. Kumar, I. O. Skillicorn, G. D. Lafferty, J. M. Levy, P. J. Bussey, C. Raine, R. J. Thompson, D. Mercer, J. B. Dainton, A. Schlösser, A. Donnachie, T. P. Yiou, and M. F. Worsell
- Subjects
Nuclear physics ,Physics ,Particle physics ,Angular distribution ,Large Hadron Collider ,Physics and Astronomy (miscellaneous) ,Meson ,Spectrometer ,Mass spectrum ,Parity (physics) ,Engineering (miscellaneous) ,Omega - Abstract
The photoproduction of the final state ω π+π−π0 has been studied as part of a survey of photoproduction in the energy range 20–70 GeV in the Omega spectrometer at CERN. The π+π−π0 system produced with the ω meson has a strongρ±π± component which is predominantlyI=1 andJπ=1+. For theωρ±π∓ state a spin-parity analysis favoursJπ=1−, and the mass spectrum peaks at 2.28±0.05 GeV. The fitted width is Γ=0.44±0.11 GeV. The photoproduction cross-section of theωρ±π∓ state, averaged over the energy range 25–60 GeV, is 150±50 nb.
- Published
- 1985
- Full Text
- View/download PDF
24. A method of field parameterisation for spectrometer magnets
- Author
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T. J. Sloan, D. Newton, T. J. Brodbeck, G.R. Brookes, G.F. Pearce, G. N. Patrick, A.M. Osborne, G. Frost, P.B. Wilkes, and D.P. Barber
- Subjects
Physics ,Magnetic measurements ,Optics ,Spectrometer ,business.industry ,Large matrices ,Magnet ,Inversion (meteorology) ,General Medicine ,business ,Magnetic field - Abstract
A method is described for using magnetic measurements taken at regularly spaced positions, of the main field component only, to parametrise a magnetic field region. The novel feature of the method is the way in which the parameters of the least squares fit can be found without the inversion of large matrices. Data are presented from a real application of the method.
- Published
- 1978
- Full Text
- View/download PDF
25. Photoproduction of πΔ(1.232) from hydrogen in the energy range 2.4–4.8 GeV
- Author
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G.F. Pearce, D.T. Williams, D.P. Barber, L. C. Y. Lee, G. Frost, J.C. Thompson, T. J. Sloan, G. N. Patrick, P.B. Wilkes, J. B. Dainton, T. J. Brodbeck, R. Marshall, G.R. Brookes, W. J. Haynes, and D. Newton
- Subjects
Physics ,Nuclear physics ,Range (particle radiation) ,Matrix (mathematics) ,Physics and Astronomy (miscellaneous) ,Hydrogen ,chemistry ,chemistry.chemical_element ,Atomic physics ,Spin density ,Photon energy ,Engineering (miscellaneous) ,Energy (signal processing) - Abstract
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.
- Published
- 1980
- Full Text
- View/download PDF
26. Observation of an ωπ0 state of mass 1.25 GeV produced by photons of energy 20–70 GeV
- Author
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K.M. Storr, Kevin M. Smith, G.R. Brookes, D. Newton, Daniel Treille, J.S. Hutton, B. D'Almagne, J.V. Morris, D. Ezra, R. George, J.C. Sleeman, J. M. Levy, James H. Roberts, J.-P. Wuthrick, M. Ibbotson, A. Rougé, Y. Pons, Pierre Petroff, D. Aston, W. Wojcik, P. Roudeau, V. Liebenau, C. Steinhauer, M. Goldberg, R. E. Hughes-Jones, A. Ferrer, G. De Rosny, I. Videau, M. Sené, W. Graves, Markus Atkinson, P.G. Hampson, I. O. Skillicorn, B. Bouquet, J. Litt, K. Müller, K. Heinloth, A.P. Waite, C. Raine, W. Galbraith, A. Wijangco, G. D. Lafferty, B. Diekmann, D. Mercer, E. Paul, S. Katsanevas, F. Richard, P. J. Bussey, R.J. Ellison, S.D.M. Gill, M.A.R. Kemp, S. Goodman, F. Kovacs, G. London, A. B. Clegg, J.B. Lane, F. Friese, M. Draper, B.R. Kumar, P. Feller, B. Drevillon, R. Bailey, B. Grossetete, Robert Richter, M. Rumpf, J. P. Dufey, H. Videau, D. Clarke, P.J. Flynn, J. Six, Austin Ball, J. Bröring, I.P. Duerdoth, M. Jung, C. De La Vaissiere, and T.P. Yiou
- Subjects
Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Particle physics ,Photon ,Astrophysics::High Energy Astrophysical Phenomena ,High Energy Physics::Experiment ,State (functional analysis) ,Nuclear Experiment ,Omega ,Energy (signal processing) - Abstract
An analysis is presented of the channel γp→π+π−π0π0p. Evidence is found for an ωπ0 enhancement of mass ≈1.25 GeV and width ≈0.3 GeV. The enhancement is a mixed spin-parity state with 1− dominant.
- Published
- 1980
- Full Text
- View/download PDF
27. Observation of the ϱ′(1600) in the channel γp→π+π−p
- Author
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J. M. Levy, W. Wojcik, S.D.M. Gill, M. Draper, B.R. Kumar, J.S. Hutton, Austin Ball, J. Bröring, A. Ferrer, F. Richard, R. E. Hughes-Jones, G. De Rosny, J.-P. Wuthrick, P. Roudeau, G.R. Brookes, H. Videau, P.G. Hampson, J.B. Lane, M. Jung, B. Diekmann, J.C. Sleeman, E. Paul, A. Rougé, C. Raine, G. London, A.P. Waite, P.J. Flynn, M. Goldberg, T.P. Yiou, Kevin M. Smith, S. Katsanevas, R. Bailey, G. D. Lafferty, M. Ibbotson, R.J. Ellison, Ch De La Vaissière, M. Sené, Daniel Treille, I. O. Skillicorn, K.M. Storr, F. Kovacs, D. Clarke, Y. Pons, M.A.R. Kemp, D. Müller, Markus Atkinson, I.P. Duerdoth, James H. Roberts, J. Six, S. Goodman, J. P. Dufey, V. Liebenau, B. D'Almagne, B. Grossetete, D. Ezra, B. Drevillon, D. Newton, B. Bouquet, H.J. Bautsch, J. Litt, A. Wijangco, P. J. Bussey, C. Steinhauer, J.V. Morris, Pierre Petroff, P. Feller, M. Rumpf, D. Aston, R. Richter, D. Mercer, I. Videau, W. Graves, K. Heinloth, W. Galbraith, and A. B. Clegg
- Subjects
Nuclear physics ,Physics ,Nuclear and High Energy Physics ,High Energy Physics::Experiment ,Channel (broadcasting) ,Nuclear Experiment ,Omega - Abstract
A dipion enhancement of mass 1.59 GeV and width 0.23 GeV is observed in the channel γp→π + π − p. The spin-parity of the enhancement is consistent with being 1 − .
- Published
- 1980
- Full Text
- View/download PDF
28. Photoproduction of π+π−π0 on hydrogen with linearly polarized photons of energy 20–70 GeV
- Author
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J. S. Hutton, J.B. Dainton, V. Liebenau, R.J. Ellison, J. V. Morris, P. Flower, C. Paterson, Robert Henderson, G. N. Patrick, P. Sharp, Richard McClatchey, H.-P. Jakob, A. P. Waite, T.J. Brodbeck, K. Heinloth, M. Atkinson, M. Reidenbach, Kevin M. Smith, D. Newton, D. Mercer, Julian Bunn, B. R. Kumar, I. O. Skillicorn, A. Schlösser, B. Diekmann, D. Barberis, J. B. Lane, W. Galbraith, G. D. Lafferty, H. Rotscheidt, Peter Bussey, M. Ibbotson, R. J. Thompson, T.J. Axon, B. Dickinson, C. Raine, T. P. Yiou, M. A. R. Kemp, M. F. Worsell, J. A. G. Morris, R.E. Hughes-Jones, G.R. Brookes, A.B. Clegg, M. Jung, P.J. Flynn, J. Laberrigue, M. Davenport, Ch De La Vaissière, J. M. Levy, J. C. Lassalle, A. Donnachie, E. Paul, K. M. Storr, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Physics ,Nuclear and High Energy Physics ,Photon ,Meson ,010308 nuclear & particles physics ,Branching fraction ,Partial wave analysis ,Dalitz plot ,Photon energy ,01 natural sciences ,7. Clean energy ,Helicity ,Nuclear physics ,0103 physical sciences ,Mass spectrum ,High Energy Physics::Experiment ,Nuclear Experiment ,010306 general physics ,Particle Physics - Experiment - Abstract
Results on photoproduction of π+π−π0 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−π0) 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−π0 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−π0 decay angular distribution in the helicity frame and by maximum likelihood fits to the π+π−π0 Dalitz plot. It is found that production of JP = 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.
- Published
- 1984
- Full Text
- View/download PDF
29. Observation of a baryon exchange dip and parton effects in backward photoproduction of ω
- Author
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G.R. Brookes, L.S. Littenberg, J. B. Dainton, R.W. Clifft, E. Gabathuler, D.L. Ward, J.C. Thompson, S.E. Rock, and R. Marshall
- Subjects
Scattering cross-section ,Physics ,Nuclear and High Energy Physics ,Particle physics ,Meson ,High Energy Physics::Phenomenology ,Nuclear Theory ,Parton ,Omega ,Term (time) ,Baryon ,Nuclear physics ,High Energy Physics::Experiment ,Nuclear Experiment ,Differential (mathematics) - Abstract
A measurement of backward photoproduction of omega mesons on protons is reported. Data are presented which show a dip in the differential cross section at u = −0.15 (GeV/ c ) 2 and an s dependence which varies strongly with u . The s dependence suggests an incoherent sum of a Regge and a parton term and differential cross sections for the two components are presented.
- Published
- 1977
- Full Text
- View/download PDF
30. Strangeness exchange in the photoproduction ofK + Λ(1520) between 2.8 and 4.8 GeV
- Author
-
J. B. Dainton, P.B. Wilkes, D. Newton, W. J. Haynes, G.F. Pearce, R. Marshall, T. J. Brodbeck, D.T. Williams, L. C. Y. Lee, D.P. Barber, G. Frost, J.C. Thompson, T. J. Sloan, G. N. Patrick, and G.R. Brookes
- Subjects
Physics ,Physics and Astronomy (miscellaneous) ,Spectrometer ,Hydrogen ,chemistry.chemical_element ,Elementary particle ,Photon energy ,Strangeness ,Nuclear physics ,Matrix (mathematics) ,chemistry ,Field theory (psychology) ,Quantum field theory ,Atomic physics ,Engineering (miscellaneous) - Abstract
A tagged photon beam (2.8
- Published
- 1980
- Full Text
- View/download PDF
31. A study of the reactions ?p??p and ?p??p and ?p???+
- Author
-
R. Marshall, P.B. Wilkes, W. J. Haynes, J. B. Dainton, L. C. Y. Lee, G. N. Patrick, D.P. Barber, T.J. Brodbeck, G. Frost, D. Newton, G.R. Brookes, J.C. Thompson, T. J. Sloan, G.F. Pearce, and D.T. Williams
- Subjects
Delta ,Physics ,Nuclear physics ,Physics and Astronomy (miscellaneous) ,Engineering (miscellaneous) ,Omega - Published
- 1984
- Full Text
- View/download PDF
32. Photoproduction of ϱϱ and ϱf systems
- Author
-
M. Ibbotson, P. S. Flower, T. J. Brodbeck, Kevin M. Smith, J. M. Levy, Markus Atkinson, Klaus Heinloth, E. Paul, Julian Bunn, A. B. Clegg, P. Flynn, B. R. Kumar, I. O. Skillicorn, D. Barberis, R. C. W. Henderson, D. Mercer, P. J. Bussey, B. Dickinson, D. Newton, B. Diekmann, P. Sharp, K. M. Storr, J. Laberrigue, A. P. Waite, V. Liebenau, J. C. Lassalle, J. B. Dainton, M. A. R. Kemp, J. B. Lane, G. N. Patrick, J. A. G. Morris, W. Galbraith, C. Raine, A. Donnachie, Richard McClatchey, M. Jung, G.R. Brookes, R. J. Thompson, M. Davenport, Ch De La Vaissière, M. Reidenbach, M. F. Worsell, H. Rotscheidt, T. P. Yiou, J. S. Hutton, H.-P. Jakob, A. Schlösser, C. Paterson, G. D. Lafferty, R. E. Hughes-Jones, R. J. Ellison, T. J. Axon, and J. V. Morris
- Subjects
Physics ,Nuclear and High Energy Physics ,Photon ,media_common.quotation_subject ,Isotropy ,Nuclear physics ,symbols.namesake ,Angular distribution ,symbols ,Feynman diagram ,Contrast (vision) ,High Energy Physics::Experiment ,Atomic physics ,Nuclear Experiment ,media_common - Abstract
A study is made of photoproduction of ϱϱ, ϱf, ϱω and ωω systems, produced with masses 1.8 GeV at high Feynman xF by photons of energy 20–70 GeV. There is evidence for a peak at a mass of ∼ 2.3 GeV with a width of ∼ 0.25 GeV in ϱ0f0and ϱ±f0 combinations. Angular distributions, in the 4π CM system, are found to be isotropic for these states, in sharp contrast to the strongly peaked angular distribution found for ϱ0ϱ0 combinations at the same mass.
- Published
- 1984
- Full Text
- View/download PDF
33. Charged ? photoproduction in the energy range 2.8?4.8 GeV
- Author
-
J. B. Dainton, R. Marshall, D. T. Williams, A.M. Osborne, W. J. Haynes, G. N. Patrick, T. J. Sloan, G.F. Pearce, G.R. Brookes, D.P. Barber, J.C. Thompson, G. Frost, P.B. Wilkes, L. C. Y. Lee, and T. J. Brodbeck
- Subjects
Nuclear physics ,Physics ,Range (particle radiation) ,Physics and Astronomy (miscellaneous) ,Model prediction ,Elementary particle ,Field theory (psychology) ,Spin density ,Quantum field theory ,Engineering (miscellaneous) ,Energy (signal processing) ,Shrinkage - Abstract
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.
- Published
- 1979
- Full Text
- View/download PDF
34. Backward photoproduction of ϱ° and f between 2.8 GeV and 4.8 GeV
- Author
-
L.S. Littenberg, R.W. Clifft, J.C. Thompson, R. Marshall, D.L. Ward, G.R. Brookes, J. B. Dainton, E. Gabathuler, and S.E. Rock
- Subjects
Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Pion ,Nuclear Theory ,Mass spectrum ,High Energy Physics::Experiment ,Nuclear Experiment - Abstract
A measurement of backward photoproduction of charged pion pairs on protons is reported. The pion pair mass spectrum shows strong ϱ ° and f production. Data are presented on the u and s dependence for ϱ O and f, together with the decay polarisation for the ϱ O .
- Published
- 1976
- Full Text
- View/download PDF
35. The reaction γp → pπ+π−π+π− for photon energies from 25 to 70 GeV
- Author
-
B. Bouquet, G.R. Brookes, B. D'Almagne, M. Sené, S. Goodman, D. Ezra, H. Videau, P.J. Flynn, I. O. Skillicorn, J.S. Hutton, Pierre Petroff, V. Liebenau, A. Wijangco, F. Kovacs, M. Ibbotson, B. Grossetete, P. J. Bussey, G. D. Lafferty, A.P. Waite, G. London, E. Paul, J.V. Morris, Austin Ball, J. Bröring, D. Newton, Kevin M. Smith, P. Roudeau, I. Videau, R. E. Hughes-Jones, F. Friese, W. Graves, R.J. Ellison, M. Jung, M.A.R. Kemp, J. Litt, C. Steinhauer, J.C. Sleeman, R. Bailey, K. Heinloth, J.B. Lane, T.P. Yiou, W. Galbraith, M. Goldberg, K.M. Storr, James H. Roberts, J. M. Levy, Ch De La Vaissière, J. Six, R. George, J. P. Dufey, J.-P. Wuthrick, I.P. Duerdoth, Daniel Treille, D. Clarke, B. Diekmann, M. Draper, B.R. Kumar, M. Rumpf, D. Aston, R. Richter, G. De Rosny, P.G. Hampson, B. Drevillon, A. Rougé, S.D.M. Gill, A. B. Clegg, Y. Pons, A. Donnachie, W. Wojcik, A. Ferrer, C. Raine, S. Katsanevas, F. Richard, K. Müller, R. J. Thompson, P. Feller, D. Mercer, and Markus Atkinson
- Subjects
Physics ,Nuclear and High Energy Physics ,Antiparticle ,Meson ,Hadron ,Elementary particle ,Helicity ,Nuclear physics ,Particle decay ,Pion ,High Energy Physics::Experiment ,Atomic physics ,Nuclear Experiment ,Nucleon - Abstract
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.
- Published
- 1981
- Full Text
- View/download PDF
36. A study of inclusive photoproduction of hyperons and antihyperons in the range of 20 to 70 GeV
- Author
-
I. Videau, W. Graves, M. Goldberg, H. Videau, James H. Roberts, C. Steinhauer, D. Mercer, F. Richard, D. Aston, R. Richter, M. Ibbotson, K.M. Storr, K. Heinloth, W. Galbraith, P.J. Flynn, Ch De La Vaissière, J.C. Sleeman, R. E. Hughes-Jones, M. Draper, B. Diekmann, B.R. Kumar, A. B. Clegg, D. Newton, Y. Pons, A. Donnachie, Pierre Petroff, A. Wijangco, B. Grossetete, Markus Atkinson, G. D. Lafferty, J. M. Levy, I.P. Duerdoth, R. George, P. J. Bussey, W. Wojcik, J.V. Morris, J.-P. Wuthrick, M. Sené, E. Paul, B. Drevillon, G. London, B. Bouquet, A. Ferrer, Kevin M. Smith, J. Bröring, A. Rougé, A.K. Ball, F. Kovacs, K. Müller, R. J. Thompson, I. O. Skillicorn, M. Jung, P. Feller, S.D.M. Gill, H.J. Bautsch, S. Goodman, V. Liebenau, T.P. Yiou, G.R. Brookes, J.S. Hutton, G. De Rosny, J.B. Lane, C. Raine, R. Bailey, S. Katsanevas, B. D'Almagne, P.G. Hampson, Daniel Treille, M.A.R. Kemp, P. Roudeau, A.P. Waite, M. Rumpf, D. Ezra, R.J. Ellison, D. Clarke, J. Litt, J. P. Dufey, and J. Six
- Subjects
Physics ,Baryon ,Nuclear physics ,Nuclear and High Energy Physics ,Antiparticle ,Particle physics ,Pion ,Meson ,Antimatter ,Hadron ,Hyperon ,Nucleon ,Particle Physics - Experiment - Abstract
Results are presented on inclusive photoproduction in hydrogen of Σ0, Σ1385±, Ξ−0, and their antiparticles for incident energies between 20 and 70 GeV. Hyperons and antihyperons are mainly measured in the kinematical range of central and forward production (xF > −0.3). We find the cross-section ratios σ(Σ 1385 + ) σ(Σ 1385 − ) = 1.4 ± 0.1 , σ( Σ 1385 + ) σ( Σ 1385 − ) = 1.3 ± 0.2 and an antiparticle/particle ratio of about 0.3 for the three sigma states. The results suggest an important role of the valence quarks of both the beam projectile and target in the production process in qualitative agreement with current ideas of quark fusion models. The inclusive production of Σ1385± is also observed in a small subsample of the events containing Λ Λ pairs. The xF distribution of Λ ( Λ ) in Λ Λ events as well as those in Λ p ( p Λ ) is the same as those in single Λ( Λ ) inclusive events. Weak signals in the K− pπ+ and Λπ+ π+ π− mass spectra are observed around a mass of 2.26 GeV.
- Published
- 1982
- Full Text
- View/download PDF
37. Observation of a charmed neutral meson produced in a high-energy photon interaction
- Author
-
M. M. Chernyavsky, M. Jung, M.A.R. Kemp, Daniel Treille, T.P. Yiou, F. Kovacs, D. Aston, Tsai Chu, G. Parrini, P. Feller, J. M. Levy, F. Friese, E. Paul, Austin Ball, J. Bröring, V.G. Larionova, M. Goldberg, J. Litt, R.E. Hughes-Jones, Robert Richter, A. Conti, James H. Roberts, J. P. Dufey, George Lafferty, A.P. Waite, R. Bailey, G.R. Brookes, K. Müller, R. J. Thompson, A. Quareni, R. Gessaroli, E. Villar, I.P. Duerdoth, Y.A. Aleksandrov, E. Higon, M. Rumpf, G. De Rosny, C. Steinhauer, F. Richard, M. I. Tretyakova, A. Wijangco, B. Diekmann, P.G. Hampson, D. Schune, J. Lory, D. Clarke, S. Katsanevas, C. De La Vaissiere, M. G. Dagliana, D. Mercer, B. Grossetete, C. Raine, André Rougé, S.D.M. Gill, J.-P. Wuthrick, G. Diambrini-Palazzi, Rajesh Kumar, A. Forino, M. Draper, B. Willot, J.C. Sleeman, B. Drevillon, K.M. Storr, Y. Pons, Peter Bussey, R.J. Ellison, W. Wojcik, Mario Sannino, J.S. Hutton, D. Ezra, P. Roudeau, Markus Atkinson, G. Tomasini, S.P. Kharlamov, G. Vanderhaeghe, L. Bravo, G. London, Pierre Petroff, I. Videau, W. Graves, M. Ibbotson, M. Dameri, B. Conforto, J.B. Lane, R. Llosa, G. di Caporiacco, H. Videau, M.I. Adamovich, R. George, A.M. Cartacci, C. Meton, J. M. Bolta, P.J. Flynn, Bianca Osculati, V. Liebenau, and D. Newton
- Subjects
Physics ,Nuclear and High Energy Physics ,Photon ,Large Hadron Collider ,Proton ,Spectrometer ,Meson ,Physics::Instrumentation and Detectors ,Omega ,Synchrotron ,law.invention ,Nuclear physics ,law ,Physics::Accelerator Physics ,High Energy Physics::Experiment ,Nuclear emulsion ,Atomic physics ,Nuclear Experiment ,Particle Physics - Experiment - Abstract
The production and decay of a D0 have been observed in a nuclear emulsion exposed to a photon beam from the CERN super proton synchroton in conjunction with the Omega spectrometer. All the decay products have been detected and measured in the emulsion and in the spectrometer. The mass of the charmed particle is 1866 ± 8 MeV/c2 and its decay time is (2.26 ± 0.05) × 10−14 s.
- Published
- 1980
- Full Text
- View/download PDF
38. Jet-like structure in the reaction γp→π+π−π+π−π+π−p
- Author
-
J.S. Hutton, F. Richard, H. Videau, D. Mercer, P.J. Flynn, I. O. Skillicorn, P. Roudeau, J. M. Levy, R. Bailey, M. Jung, R.J. Ellison, A. Rougé, M. Ibbotson, F. Kovacs, Kevin M. Smith, T.P. Yiou, B. D'Almagne, J. P. Dufey, R. E. Hughes-Jones, K. Müller, R. J. Thompson, A. B. Clegg, P. Feller, G.R. Brookes, S. Goodman, Ch De La Vaissière, J.C. Sleeman, J.V. Morris, R. George, M. Draper, B.R. Kumar, James H. Roberts, C. Raine, J.-P. Wuthrick, G. De Rosny, S. Katsanevas, F. Friese, D. Ezra, K.M. Storr, M. Goldberg, P.G. Hampson, I.P. Duerdoth, C. Steinhauer, Markus Atkinson, A.P. Waite, Daniel Treille, M. Sené, Y. Pons, E. Paul, J. Litt, A. Donnachie, D. Clarke, W. Wojcik, A. Ferrer, B. Bouquet, A. Wijangco, Austin Ball, J. Bröring, P. J. Bussey, J. Six, G. London, S.D.M. Gill, G. D. Lafferty, Pierre Petroff, J.B. Lane, V. Liebenau, B. Diekmann, M.A.R. Kemp, B. Grossetete, I. Videau, W. Graves, K. Heinloth, W. Galbraith, D. Newton, M. Rumpf, D. Aston, R. Richter, and B. Drevillon
- Subjects
Physics ,Nuclear reaction ,Nuclear and High Energy Physics ,Annihilation ,Pion ,Meson ,Hadron ,High Energy Physics::Experiment ,Elementary particle ,Atomic physics ,Omega ,Boson - Abstract
We report on diffractive production of 6 π systems with a continuum of masses from 2 to 5 GeV/c 2 in the reaction γ p→ π + π − π + π − π + π - p. The event structure is compared in detail with Monte Carlo studies of p T limited phase space, and with the jets observed in hadronic systems produced by electron-positron annihilation. Strong similarities are found. For this jet-like structure of the 6 π system the axis is consistent with being along the incident photon direction.
- Published
- 1980
- Full Text
- View/download PDF
39. Observation of pairs of charmed particles produced by high-energy photons in nuclear emulsions coupled with a magnetic spectrometer
- Author
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G.R. Brookes, J.B. Lane, R. Llosa, J. C. Lassalle, D. Newton, M. Dameri, A. Ruiz, W. Galbraith, A. Conti, G. Parrini, Y. A. Alexandrov, E. Higon, A.M. Cartacci, Giovanni Crosetti, R. Gessaroli, M. Davenport, J. P. Dufey, B. Willot, T. Brodbeck, A.I Schlösser, N. G. Peresadko, G. N. Patrick, K. M. Romanovskaya, S. P. Kharlamov, A. Mattei, G. I. Orlova, K.M. Storr, C. Meton, A.P. Waite, G. di Caporiacco, G. Diambrini-Palazzi, J. M. Bolta, Markus Atkinson, George Lafferty, M. m. Chernyavski, A. Forino, A. Quareni Vignudelli, J. Lory, M. I. Tretyakova, V. G. Larionova, D. Schune, J.S. Hutton, D. Mercer, B. Monteleoni-Conforto, Bianca Osculati, G. Vanderhaeghe, C. Raine, Peter Bussey, R. McClatchey, R.J. Ellison, R.E. Hughes-Jones, Mario Sannino, M. Ibbotson, B. R. Kumar, G. Tomasini, L. Bravo, J. V. Morris, M.I. Adamivich, E. Villar, M.G. Dagliana, K. Heinloth, and Tsai Chu
- Subjects
Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Particle physics ,High energy photon ,Large Hadron Collider ,Meson ,Spectrometer ,D meson ,Statistical analysis ,Photon beam ,Particle Physics - Experiment - Abstract
Preliminary results of an experiment using nuclear emulsions exposed to a tagged photon beam at the CERN SPS (experiment WA58) are presented. Six events showing pairs of charmed particles have been found. One of these has been interpreted as an associated production of Λc+ and D 0. The mean lifetime of the neutral D meson based on three events is τ0 = (0.58−0.2+0.8 × 10−13 s,, whereas a statistical analysis of eight charged charmed particles, assumed to be D mesons, leads to an estimate of the mean lifetime of τ± ≈ 4.4 × 10−13 s.
- Published
- 1981
- Full Text
- View/download PDF
40. Total absorption measurements of 100–250 MeV photons in carbon and aluminium
- Author
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J.G. Rutherglen, R. Railton, G.R. Brookes, and I.L. Smith
- Subjects
Physics ,Nuclear reaction ,Nuclear and High Energy Physics ,Photon ,Carbon-12 ,Bremsstrahlung ,chemistry.chemical_element ,Electron ,Synchrotron ,law.invention ,Nuclear physics ,chemistry ,law ,Aluminium ,Physics::Accelerator Physics ,Atomic physics ,Nuclear Experiment ,Absorption (electromagnetic radiation) - Abstract
The total cross sections for absorption of photons in carbon and aluminium have been measured for photon energies of 100, 150, 200 and 250 MeV. The γ-ray bremsstrahlung beam from the 300 MeV electron synchrotron at Glasgow University was used as the source of photons. Two magnetic pair spectrometers were used as photon detectors. The results obtained are in close agreement with theoretical calculations of the total cross sections.
- Published
- 1967
- Full Text
- View/download PDF
41. The recoil proton polarization in the reaction γp → πop in the third resonance region
- Author
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Kevin M. Smith, R. Railton, G.R. Brookes, W. Galbraith, J.G. Rutherglen, M.N. Prentice, P. J. Bussey, G.H. Eaton, F. Combley, and J.E. Shaw
- Subjects
Recoil proton ,Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Angular distribution ,Photon ,Nuclear Theory ,Physics::Accelerator Physics ,Photon beams ,Atomic physics ,Nuclear Experiment ,Polarization (waves) - Abstract
Measurements have been made of the polarization of the recoil proton in the process γp → πop for photon energies of 850 - 1250 MeV and centre-of-mass angles of 80° - 125°. The results, which are to a typical accuracy of ±0.09, show a marked disagreement with previous phenomenological analyses above 1000 MeV.
- Published
- 1972
- Full Text
- View/download PDF
42. Total Hadronic Cross Section ofγRays in Hydrogen in the Energy Range 0.265-4.215 GeV
- Author
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G.R. Brookes, W. Galbraith, J.C. Thompson, G.M. Lewis, N.R.S. Tait, T.A. Armstrong, A.S. Clough, D.W.L. Tolfree, W.R. Hogg, W.R. Rawlinson, J.H. Freeland, A.F. King, and A.W. Robertson
- Subjects
Nuclear physics ,Physics ,Range (particle radiation) ,Cross section (physics) ,Amplitude ,Scattering ,Hadron ,Production (computer science) ,Resonance (particle physics) ,Energy (signal processing) - Abstract
The total cross section of $\ensuremath{\gamma}$ rays in hydrogen resulting in hadron production, ${\ensuremath{\sigma}}_{T}$, has been measured over the energy range 265-4215 MeV. A tagging system with narrow energy bins was employed. Structure in the resonance region followed by a steady fall with energy has been observed and the results are analyzed. The forward amplitude of $\ensuremath{\gamma}$-proton scattering is evaluated, and its behavior in the Argand diagram studied as a function of energy. The relationships of the measurements to Regge-pole theory and the vector-dominance model are detailed.
- Published
- 1972
- Full Text
- View/download PDF
43. A high resolution wide range photon tagging system
- Author
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W.R. Rawlinson, M.D. Rousseau, G.R. Brookes, S. Hinds, A.G. Wardle, and D.W.L. Tolfree
- Subjects
Physics ,Range (particle radiation) ,Photon ,business.industry ,Resolution (electron density) ,Bremsstrahlung ,General Medicine ,Spectral line ,Radiation length ,Nuclear physics ,Optics ,Cathode ray ,business ,Energy (signal processing) - Abstract
A photon tagging array which measures the energy of photons in a bremsstrahlung spectrum is described. The apparatus covers an energy range of 1600 MeV starting 250 MeV below the energy of the incident electron beam. Sixty-four tagged channels provide a theoretical resolution of ±12.5MeV and measurements indicate the overall resolution, using a 1 100 radiation length radiator, to be better than ±17.5MeV. Design and constructional features are incorporated which permit considerable reductions in the installation, survey and monitoring requirements.
- Published
- 1970
- Full Text
- View/download PDF
44. The quasi-deuteron photodisintegration process in lithium, carbon and calcium
- Author
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J.G. Rutherglen, I.L. Smith, J. Garvey, and G.R. Brookes
- Subjects
Nuclear reaction ,Physics ,Nuclear and High Energy Physics ,Nuclear Theory ,Carbon-12 ,Form factor (quantum field theory) ,Nuclear physics ,Deuterium ,Photodisintegration ,Scintillation counter ,Neutron ,Atomic physics ,Nuclear Experiment ,Ground state - Abstract
An experiment is described in which the quasi-deuteron photodisintegration process was studied in the nuclei 7 Li, 12 C and 40 Ca, for photons of energy between about 150 and 250 MeV. Angular distributions of protons of energy between about 60 and 130 MeV, produced in coincidence with neutrons of energy 74.9 ± 17.0 MeV (FWHM) emitted at 90° in the laboratory, were measured with a spark chamber, scintillation counter telescope. The neutrons were detected by a scintillation counter and their energies determined by a time-of-flight method. The form-factor, F ( P ), defined as the probability of finding a neutron-proton pair of momentum P and zero separation in the ground state of the nucleus, is derived and used to determine the theoretical angular distributions. The cross section for the process is written as L ( NZ / A ) σ d , where σ d is the cross section for the photodisintegration of a deuteron and L is a constant. Comparison between theory and experiment leads to values of L for the three target nuclei in good agreement with that previously determined by this group for oxygen [1], and also with that obtained by Bishop et al. [2].
- Published
- 1967
- Full Text
- View/download PDF
45. The total photon-proton cross section for hadron production
- Author
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J.C. Thompson, G.R. Brookes, W. Galbraith, A.S. Clough, A.W. Robertson, G.M. Lewis, W.R. Rawlinson, W.R. Hogg, A.F. King, N.R.S. Tait, D.W.L. Tolfree, J.H. Freeland, and T. Armstrong
- Subjects
Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Cross section (physics) ,Particle physics ,Range (particle radiation) ,Photon ,Proton ,Nuclear Theory ,Hadron ,Physics::Accelerator Physics ,Electron ,Nuclear Experiment - Abstract
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.
- Published
- 1971
- Full Text
- View/download PDF
46. The total photon deuteron hadronic cross section in the energy range 0.265–4.215 GeV
- Author
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J.C. Thompson, G.M. Lewis, A.S. Clough, G.R. Brookes, W. Galbraith, T. Armstrong, D.W.L. Tolfree, A.W. Robertson, J.H. Freeland, W.R. Hogg, A.F. King, W.R. Rawlinson, and N.R.S. Tait
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle physics ,Photon ,Proton ,Nuclear Theory ,Hadron ,Resonance (particle physics) ,Nuclear physics ,Cross section (physics) ,Neutron cross section ,Neutron ,Nuclear cross section ,Nuclear Experiment - Abstract
The total cross section for photoproduction of hadrons on the deutron, σTd, has been measured for photon energies in the range 0.265–40215 GeV. From this, using results for the photon total cross section, obtained previously with the same apparatus, the neutron total cross section has been determined in the resonance region. The resonant structure is found to be quite different from that for the proton. Thereafter the neutron cross section falls off steadily with energy, and the values obtained are consistently lower than those for the proton. Forward scattering amplitudes have been evaluated for the deuteron.
- Published
- 1972
- Full Text
- View/download PDF
47. Total Hadronic Photoabsorption Cross Sections of Nuclei for Photons in the GeV Energy Range
- Author
-
A.S. Clough, A.F. King, D.W.L. Tolfree, J.H. Freeland, W.R. Hogg, W.R. Rawlinson, J.C. Thompson, G.M. Lewis, G.R. Brookes, W. Galbraith, N.R.S. Tait, A.W. Robertson, and T.A. Armstrong
- Subjects
Nuclear physics ,Physics ,Range (particle radiation) ,Photon ,Nuclear Theory ,Hadron ,Physics::Atomic and Molecular Clusters ,High Energy Physics::Experiment ,Photon beam ,Atomic physics ,Nuclear Experiment - Abstract
The total hadronic photoabsorption cross sections of a number of nuclei (C, Al, Cu, Nb, Sn, Ta, Pb) have been studied in detail using a tagged photon beam over the energy range 1.7-4 GeV. The results are described, and compared with models of photoabsorption. (auth)
- Published
- 1973
- Full Text
- View/download PDF
48. Measurements of the polarisation of the recoil proton in elastic electron proton scattering at q2 = 1.3, 1.5 and 1.9 (GeV/c)2
- Author
-
Kevin M. Smith, G.R. Brookes, A.S. Watson, G.M. Lewis, R. Railton, M.N. Prentice, W.R. Hogg, J.H. Freeland, G.H. Eaton, J.G. Rutherglen, W. Galbraith, J.E. Shaw, F. Combley, and H.C. Kirkman
- Subjects
Elastic scattering ,Physics ,Nuclear and High Energy Physics ,Photon ,Scattering ,Electron ,Polarization (waves) ,Nuclear physics ,Recoil proton ,Amplitude ,Proton scattering ,High Energy Physics::Experiment ,Astrophysics::Earth and Planetary Astrophysics ,Atomic physics ,Nuclear Experiment - Abstract
An experiment has been carried out to determine the imaginary part of the two-photon exchange amplitude by measuring the polarisation of the recoil proton in elastic electron-proton scattering. The polirisation was found to be −0.006 ± 0.030 at q2 = 1.3 (GeV/c)2, +0.052 ± 0.55 at 1.5 (GeV/c)2 and +0.065 ± 0.087 at 1.9 (GeV/c)2.
- Published
- 1970
- Full Text
- View/download PDF
49. Total absorption measurements of 100–250 MeV photons in hydrogen
- Author
-
R. Railton, I.L. Smith, J.G. Rutherglen, and G.R. Brookes
- Subjects
Physics ,Nuclear and High Energy Physics ,Photon ,Hydrogen ,chemistry.chemical_element ,Electron ,Electric charge ,Synchrotron ,law.invention ,Nuclear physics ,Cross section (physics) ,chemistry ,law ,Physics::Accelerator Physics ,Atomic physics ,Nuclear Experiment ,Absorption (electromagnetic radiation) ,Beam (structure) - Abstract
The total cross section for the absorption of photons in hydrogen has been measured for photon energies of 100, 150, 200 and 250 MeV. The γ-rays bremsteahlung beam from the 300 MeV electron synchrotron at Glasgow University was used as the source of photons. Two magnetic pair spectrometers were used as photon detectors. From the results, values of the cross section for triplet production have been derived which are in better agreement with theoretical calculations based on the predictions of Borsellino than those of Votruba.
- Published
- 1967
- Full Text
- View/download PDF
50. The decay of the ϱ′ (1600) into π+π−π0π0
- Author
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S.D.M. Gill, H. Rotscheidt, H.-P. Jakob, C. Paterson, M. Jung, P. S. Flower, R. C. W. Henderson, Klaus Heinloth, R. E. Hughes-Jones, J. M. Levy, B. Diekmann, George Lafferty, D. Mercer, R. J. Ellison, T. J. Axon, Kevin M. Smith, Markus Atkinson, Julian Bunn, J. B. Lane, A. Donnachie, D. Barberis, P. J. Bussey, M. Reidenbach, B. R. Kumar, I. O. Skillicorn, M. Ibbotson, T. P. Yiou, G. N. Patrick, J. C. Lassalle, J. S. Hutton, D. Newton, M. A. R. Kemp, K. M. Storr, T. J. Brodbeck, W. Galbraith, A. Schlösser, E. Paul, B. Dickinson, M. Draper, V. Liebenau, M. Davenport, Ch De La Vaissière, R. J. Thompson, A. P. Waite, C. Raine, A. B. Clegg, P. Flynn, P. Sharp, J. B. Dainton, J. A. G. Morris, Richard McClatchey, G.R. Brookes, and J. Laberigue
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle decay ,Antiparticle ,Pion ,Meson ,Hadron ,Mass spectrum ,Atomic physics ,Photon energy ,Nucleon - Abstract
Measurements of the reaction γ p→ π + π − π 0 π 0 p are presented for the photon energy range 20 to 70 GeV. The 1.6 GeV peak in the mass spectrum of the π + π − π 0 π 0 system is shown to decay dominantly to ϱ ± π ∓ π 0 . The ratio of ϱ 0 π 0 π 0 to ϱ ± π ∓ π 0 is less than 0.15, thus eliminating ϱϵ as the dominant decay mode of ϱ ′ (1600).
- Published
- 1982
- Full Text
- View/download PDF
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