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Pi+ p elastic scattering at 3.6 gev/c

Macnaughton, J. ; Butler, W.R. ; Coyne, D.G. ; et al.

Nucl.Phys.B 33 (1971) 101-108, 1971.

Inspire Record 68509 DOI 10.17182/hepdata.33221

The elastic scattering of 3.6 GeV/ c π + mesons by protons has been studied in a hydrogen bubble chamber experiment. The elastic cross section has a measured value of 7.07 ± 0.20 mb. The forward diffraction peak has been fitted in the region 0.05 ≦ − t ≦ 0.6 (GeV/ c ) 2 by a form (d σ /d t ) = Ae Bt , where A = 46.5 ± 1.8 mb/(GeV/ c ) 2 and B = 6.85 ± 0.20 (GeV/ c ) −2 . From this fit and the optical theorem, the magnitude of the ratio of real to imaginary forward amplitude is 0.39 ± 0.06, in reasonable agreement with dispersion relation calculations and simple Regge model predictions.

3 data tables

Table 1

No description provided.

Table 2

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Table 3

No description provided.

New evidence for the p-11(1470) resonance in pi- p ---> n pi0 below 600 mev

Hauser, M.G. ; Chen, K.W. ; Crean, P.A. ;

Phys.Lett.B 35 (1971) 252-256, 1971.

Inspire Record 69248 DOI 10.17182/hepdata.28485

The differential cross section for π − p → n π o has been measured in detail from 150 to 600 MeV. The backward cross section has a previously unobserved dramatic dip at 425 MeV. We interpret this dip in terms of interference between the P 33 (1236) and the P 11 (1470) resonances. These data provide strong evidence for the adequacy of the phase shift solutions in this energy range.

116 data tables

Table 1

SCALED TO AGREE WITH SOLUTION AT 225 MEV AND THEN INTERPOLATED.

Table 2

SCALED TO AGREE WITH SOLUTION AT 225 MEV AND THEN INTERPOLATED.

Table 3

SCALED TO AGREE WITH SOLUTION AT 225 MEV AND THEN INTERPOLATED.

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Investigation of the phi-meson resonance by electron-positron colliding beams

Balakin, V.E. ; Budker, G.I. ; Pakhtusova, E.V. ; et al.

Phys.Lett.B 34 (1971) 328-332, 1971.

Inspire Record 69313 DOI 10.17182/hepdata.28704

Using the colliding beam machine, VEPP-2, the excitation curve of the ø-meson resonance was investigated in the three main decay modes. The resonance parameters obtained are the width, the total cross-section and the branching ratios. Namely: Γ = (4.67 ± 0.42) Mev B ( K + K − ) = (54.0 ± 3,4) % σ o = (3.96 ± 0.35) μB B ( K o s K O L ) = (25.7 ±3,0) % B ( e + e − = (2,81 ± 0.25) × 10 −4 B ( π + π − π o ) = (20.3 ± 4,2) %

2 data tables

Table 1

BREIT-WIGNER FITS TO DATA POINTS AT 9 ENERGIES AROUND PHI FOR EACH CHANNEL. PEAK CROSS SECTIONS QUOTED.

Table 2

PION FORM FACTOR AT PHI MASS, ALLOWING FOR POSSIBLE INTERFERENCE.

Coincidence measurements of single-pion electroproduction near the delta(1236) resonance

Mistretta, C. ; Appel, J.A. ; Budnitz, R.J. ; et al.

Phys.Rev. 184 (1969) 1487-1507, 1969.

Inspire Record 62286 DOI 10.17182/hepdata.26474

Differential cross sections for the reactions e−+p→e−+p+π0 and e−+p→e−+n+π+ have been measured near the Δ(1236) resonance at four-momentum transfers of 0.05, 0.13, 0.25, and 0.4 (GeV/c)2. A few measurements of the π+ angular distribution have been obtained at a four-momentum transfer of 0.6 (GeV/c)2. Cross sections for the π0 reaction are compared with dispersion-theory predictions at several pion-nucleon c.m. energies for each four-momentum transfer. A phenomenological analysis of the π0 results leads to the determination of the magnetic dipole and electric quadrupole partial-wave amplitudes and the γNΔ transition form factor. Evidence is found for the existence of a significant scaler-transverse interference term in the cross section, which is tentatively associated with the resonant scaler quadrupole interaction. Cross sections for π+ electroproduction are compared with dispersion theories using the pion form factor as a free parameter. The results suggest a form factor similar to that of the proton. A fit to the form-factor results, using the ρ-dominance model, requires mρ=560±80 MeV. The rms pion charge radius is estimated to be 〈r2〉12=0.86±0.14 F.

5 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

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Measurements of the polarisation of the recoil proton in elastic electron proton scattering at q-squared=1.3, 1.5 and 1.9(gev/c)squared

Kirkman, H.C. ; Railton, R. ; Rutherglen, J.G. ; et al.

Phys.Lett.B 32 (1970) 519-522, 1970.

Inspire Record 63101 DOI 10.17182/hepdata.28765

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 q 2 = 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 .

1 data table

Table 1

No description provided.

Elastic electron-proton scattering cross-sections measured by a coincidence technique

Goitein, M. ; Budnitz, R.J. ; Carroll, L. ; et al.

Phys.Rev.D 1 (1970) 2449-2476, 1970.

Inspire Record 61717 DOI 10.17182/hepdata.25070

We have measured elastic electron-proton scattering cross sections in the range of four-momentum transfers from 7 F−2[0.27 (GeV/c)2] to 150 F−2 [5.84 (GeV/c)2] and at scattered electron angles of between 20° and 34° in the laboratory. The estimated errors in the cross sections range from ±2.1% at the lowest momentum transfer to ±9.6% at the highest. Both the scattered electron and the recoil proton were detected, resulting in an overdetermination of the kinematics. When the constraint of a coincident proton is removed, there is no significant change in the estimated cross sections.

15 data tables

Table 1

No description provided.

Table 2

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Table 3

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Photoproduction of neutral rho mesons from complex nuclei

Alvensleben, H. ; Becker, U. ; Bertram, W.K. ; et al.

Phys.Rev.Lett. 24 (1970) 786-792, 1970.

Inspire Record 62918 DOI 10.17182/hepdata.21623

We present results of measurements on photoproduction of ρ mesons. Analysis of 106 measured ρ events in a four-dimensional data matrix dσ(A, m, p, t⊥)dΩdm with dimensions 14×20×10×20 yields precise information on nuclear density distributions for ρ production. We obtain for the Woods-Saxon radii R(A)=(1.12±0.02)A13 and, using the vector dominance model, σρN=26.7±2.0 mb and γρ24π=0.57±0.10.

1 data table

Table 1

No description provided.

Measurement of Proton Electromagnetic Form Factors at High Momentum Transfers

Chen, K.W. ; Dunning, J.R. ; Cone, A.A. ; et al.

Phys.Rev. 141 (1966) 1267-1285, 1966.

Inspire Record 50783 DOI 10.17182/hepdata.26655

Elastic electron-proton scattering cross sections have been measured using the internal beam of the 6-BeV Cambridge Electron Accelerator at laboratory scattering angles between 31° and 90° for values of the four-momentum transfer squared ranging from q2=0.389 to 6.81 (BeV/c)2 (q2=10 to 175F−2). Incident electron energies ranged from 1.0 to 6.0 BeV. Scattered electrons from an internal liquid-hydrogen target were momentum-analyzed using a single quadrupole spectrometer capable of momentum analysis up to 3.0 BeV/c. Čerenkov and shower counters were used to help reject pion and low-energy background. The cross sections presented are absolute cross sections with experimental errors ranging from 6.8% to 20%. Separation of proton electromagnetic form factors have been made for all but the two highest momentum transfer points, using the Rosenbluth formula. Both form factors, GEp and GMp, were observed to continue to decrease as the momentum transfer increases. An upper limit to the possible asymptotic values of the proton electromagnetic form factors has been established.

9 data tables

Table 1

No description provided.

Table 2

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Table 3

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