Armstrong, D.S.
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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
Table 1

No description provided.


Total hadronic cross-section of gamma rays in hydrogen in the energy range 0.265-GeV to 4.215-GeV

Armstrong, T.A. ; Hogg, W.R. ; Lewis, G.M. ; et al.
Phys.Rev.D 5 (1972) 1640-1652, 1972.
Inspire Record 67298 DOI 10.17182/hepdata.22462

The total cross section of γ rays in hydrogen resulting in hadron production, σT, 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 γ-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.

2 data tables
Table 1

No description provided.

Table 2

SPIN AVERAGED FORWARD COMPTON SCATTERING AMPLITUDE. IM(AMP) WAS CALCULATED VIA THE OPTICAL THEOREM FROM A SMOOTH FIT TO THE DATA, AND USED IN THE DISPERSION RELATION TO CALCULATE RE(AMP). AT THRESHOLD THE THOMSON AMPLITUDE IS -3.0 MUB*GEV.


The total pair production cross-section of gamma-rays in hydrogen and deuterium

Rawlinson, W.R. ; Tait, N.R.S. ; Thompson, J.C. ; et al.
Nucl.Phys.B 45 (1972) 41-46, 1972.
Inspire Record 75026 DOI 10.17182/hepdata.32781

The total electromagnetic cross sections of g-rays in hydrogen and deuterium have been measured over the energy range 265–4215 MeV using a photon tagging system. From these measurements, the total pair production cross sections are obtained, and the results are found to be in good agreement with the predictions of Jost, Luttinger and Slotnick.

2 data tables
Table 1

Axis error includes +- 1/1 contribution.

Table 2

Axis error includes +- 1/1 contribution.


The total photon deuteron hadronic cross-section in the energy range 0.265-4.215 gev

Armstrong, T.A. ; Hogg, W.R. ; Lewis, G.M. ; et al.
Nucl.Phys.B 41 (1972) 445-473, 1972.
Inspire Record 75161 DOI 10.17182/hepdata.32884

The total cross section for photoproduction of hadrons on the deutron, σ T d , 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.

4 data tables
Table 1

No description provided.

Table 2

RESONANCE REGION. UNSMEARING CORRECTION APPLIED, GLAUBER CORRECTION NEGLIGIBLE.

Table 3

HIGHER ENERGY CROSS SECTIONS, IN 200 MEV BINS. OVERALL 3 PCT SYSTEMATIC ERROR IN ADDITION TO QUOTED STATISTICAL ERRORS. NEUTRON/PROTON CROSS SECTION RATIO HAS MEAN VALUE OF 0.94 +- 0.01.

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Comparison of new data on anti-p p --> pi- pi+ and other two meson states at 2.3-gev/c

Fields, T. ; Cooper, W.A. ; Rhines, D.S. ; et al.
Phys.Lett.B 40 (1972) 503-506, 1972.
Inspire Record 75681 DOI 10.17182/hepdata.28267

Complete angular distributions for the reactions p p → π − π + and other two meson states at 2.3 GeV/ c are presented. The extraordinary π − π + angular distribution is contrasted with the other final states and the predictions of simple models. A favourable comparison is made with the qualitative features of a dual model involving high mass meson states with a strong degeneracy with respect to I -spin.

2 data tables
Table 1

SOME ANGULAR DISTRIBUTIONS ALSO PRESENTED.

Table 2

K* NEUTRAL TO CHARGED PRODUCTION RATIO.


Absence of discrete s-channel resonances in anti-p p interactions at intermediate energies

Fields, T. ; Cooper, W.A. ; Rhines, D.S. ; et al.
Phys.Rev.Lett. 27 (1971) 1749-1752, 1971.
Inspire Record 75556 DOI 10.17182/hepdata.21475

We give new experimental results on ρω interference and two-body cross sections in p¯p annihilation at 2.3GeVc. These are used, together with ρω interference results from lower energies, to argue that the annihilation process is not mediated by discrete s-channel mesonic resonances in the mass range 2.1-2.6 GeV.

1 data table
Table 1

No description provided.


Observation of the reaction pi- p ---> anti-p d from 4 to 6 gev/c

Pawlicki, A.J. ; Ayres, D.S. ; Diebold, R. ; et al.
Phys.Rev.Lett. 31 (1973) 665-667, 1973.
Inspire Record 83780 DOI 10.17182/hepdata.21336

Differential cross sections have been measured for the reaction π−p→p¯d. At 4 GeV/c the total cross section is 0.58 ± 0.08 μb with an angular distribution consistent with isotropy. At 5 GeV/c a pronounced forward dip occurs. In contradiction to simple baryon-exchange models, the cross section is found to be an order of magnitude smaller than that for the line-reversed reaction pp→π+d. Upper limits for π−d→p¯t were also found.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Comparison of particle-antiparticle elastic scattering from 3 to 6 gev/c

Ambats, I. ; Ayres, D.S. ; Diebold, R. ; et al.
Phys.Rev.Lett. 29 (1972) 1415-1419, 1972.
Inspire Record 84577 DOI 10.17182/hepdata.21445

Differential cross sections for π±p, K±p, pp, and p¯p elastic scattering were measured at 3, 3.65, 5, and 6 GeVc for momentum transfers from 0.03 to 1.5 GeV2 using the Argonne effective mass spectrometer. Particular attention was paid to the relative particle-antiparticle normalization. The crossover points are consistent with no energy dependence, average values being 0.14 ± 0.03, 1.190 ± 0.005, and 0.160 ± 0.007 GeV2 for π's, K's, and protons, respectively.

1 data table
Table 1

No description provided.


ANTI-PROTON - PROTON ANNIHILATION INTO FIVE AND MORE PIONS AT 2.32-GeV/c

Oren, Y. ; Cooper, W.A. ; Fields, T. ; et al.
Nucl.Phys.B 71 (1974) 189-210, 1974.
Inspire Record 80613 DOI 10.17182/hepdata.32346

High statistics data on p p annihilation into five and more pions at 2.32 GeV/ c are presented. Cross sections for various final states and for the production of meson resonances have been determined. The Dalitz plot asymmetry for some 4 800 ω decay events produced in p p → 2π + 2π − π 0 is found to be consistent with zero. Upper limits for the production of exotic meson resonances are presented.

1 data table
Table 1

No description provided.


Systematic study of pi+- p, k+- p, p p, and anti-p p forward elastic scattering from 3 to 6 gev/c

Ambats, I. ; Ayres, D.S. ; Diebold, R. ; et al.
Phys.Rev.D 9 (1974) 1179-1209, 1974.
Inspire Record 92992 DOI 10.17182/hepdata.3409

Measurements of π±p, K±p, pp, and p¯p elastic scattering are presented for incident momenta of 3, 3.65, 5, and 6 GeVc and momentum transfers typically 0.03 to 1.8 GeV2. The angle and momentum of the scattered particle were measured with the Argonne Effective Mass Spectrometer for 300 000 events, yielding 930 cross-section values with an uncertainty in absolute normalization of ±4%. Only the K+ and proton data show any significant change in slope of the forward diffraction peak with incident momentum. The particle-antiparticle crossover positions are consistent with no energy dependence, average values being 0.14 ± 0.03, 0.190 ± 0.006, and 0.162 ± 0.004 GeV2 for π' s, K' s, and protons, respectively; these errors reflect both statistics and the ±1.5% uncertainty in particle-antiparticle relative normalization. Differences between particle and antiparticle cross sections isolate interference terms between amplitudes of opposite C parity in the t channel; these differences indicate that the imaginary part of the odd-C nonflip-helicity amplitude has a J0(r(−t)12) structure for −t<0.8 GeV2, as predicted by strong absorption models. The cross-section differences for K± and proton-antiproton are in qualitative agreement with the predictions of ω universality, the agreement improving with increasing energy. The corresponding quark-model predictions relating the π± and K± differences failed by more than a factor of 2. We have combined our π± cross sections with other data to better determine the πN amplitudes in a model-independent way; results of this analysis are presented.

18 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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