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Differential cross-sections for the reactions $p + p \to D + \pi^+$ and $p + p \to D + \rho^+$ at 21-GeV/c

Allaby, J.V. ; Binon, F.G. ; Diddens, A.N. ; et al.

Phys.Lett.B 29 (1969) 198-202, 1969.

Inspire Record 56770 DOI 10.17182/hepdata.28992

Results are presented from an experiment in which high-energy deuterons, produced by proton-proton interactions at 21.1 GeV/ c incident momentum, were detected over a range of angles from 12.5 mrad to 60 mrad in the laboratory system. From the momentum spectra of the deuterons, the final states D + π + and D + ϱ + have been identified. The angular distribution for these reactions are presented and compared with previous data at lower energies.

5 data tables

Table 1

The statistical errors are presented.

Table 2

The statistical errors are presented.

Table 3

The statistical errors are presented. The data are from previous publications.

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Low-energy differential cross-sections of pion proton (pi+- p) scattering. 2: Phase shifts at T(pi) = 32.7-MeV, 45.1-MeV, and 68.6-MeV

Joram, C. ; Metzler, M. ; Jaki, J. ; et al.

Phys.Rev.C 51 (1995) 2159-2165, 1995.

Inspire Record 404659 DOI 10.17182/hepdata.25955

We report on measurements of the differential π±p cross section at pion energies Tπ=32.7, 45.1, and 68.6 MeV. The measurements, covering the angular range 25°≤θlab≤123°, have been carried out at the Paul-Scherrer-Institute (PSI) in Villigen, Switzerland, employing the magnet spectrometer LEPS. The absolute normalization of the π±p cross sections have been achieved by relating them to the electromagnetic cross sections of μ±12C scattering. The results are in agreement with those of our preceding measurements at Tπ=32.2 and 45.1 MeV insofar as they overlap with the region of the Coulomb nuclear interference investigated there. A comparison with the predictions of the Karlsruhe-Helsinki phase shift analysis KH80, which has formed the basis for the determination of the ‘‘experimental’’ σ term, reveals considerable deviations. These are most pronounced for the π+p cross sections at Tπ=32.7 and 45.1 MeV. Single energy partial wave fits result in S-wave contributions, which are about 1° lower in magnitude then those specified by the KH80 solution. The data at 68.6 MeV are in good agreement with the phase shift analysis.

3 data tables

Table 1

Statistical and systematic errors are addet in quadrature.

Table 2

Statistical and systematic errors are addet in quadrature.

Table 3

Statistical and systematic errors are addet in quadrature.

Low-energy differential cross-sections of pion proton (pi+- p) scattering. 1: The Isospin even forward scattering amplitude at T(pi) = 32.2-MeV and 44.6-MeV

Joram, C. ; Metzler, M. ; Jaki, J. ; et al.

Phys.Rev.C 51 (1995) 2144-2158, 1995.

Inspire Record 404658 DOI 10.17182/hepdata.25972

The values of the pion nucleon (πN) σ term, as determined, on the one hand, from experimental pion nucleon scattering by means of dispersion relations and, on the other hand, from baryon masses by means of chiral perturbation theory, differ by 10 to 15 MeV. The origin of this discrepancy is not yet understood. If the difference between the two values is attributed to the scalar current of strange sea quark pairs within the proton, the contribution to the proton mass would be of the order of 120 MeV. The discrepancy may hint at either theoretical deficiencies or an inadequate πN database. In order to provide reliable experimental data we have measured angular distributions of elastic pion proton scattering at pion energies Tπ=32.2 and 44.6 MeV using the magnet spectrometer LEPS located at the Paul-Scherrer-Institute (PSI) in Villigen, Switzerland. From the data covering the region of the Coulomb nuclear interference, the real parts of the isospin-even forward scattering amplitude ReD+(t=0), have been determined as a function of energy. The results have been compared with the predictions of the Karlsruhe-Helsinki phase shift analysis KH80, revealing discrepancies most pronounced for the π+p data. The experimentally determined values for ReD+(t=0), however, support the KH80 prediction (which is based on πN data available in 1979).

2 data tables

Table 1

Statistical and systematic errors are addet in quadrature.

Table 2

Statistical and systematic errors are addet in quadrature.

Measurements of elastic electron - proton scattering at large momentum transfer

Sill, A.F. ; Arnold, R.G. ; Bosted, Peter E. ; et al.

Phys.Rev.D 48 (1993) 29-55, 1993.

Inspire Record 341324 DOI 10.17182/hepdata.22584

Measurements of the forward-angle differential cross section for elastic electron-proton scattering were made in the range of momentum transfer from Q2=2.9 to 31.3 (GeV/c)2 using an electron beam at the Stanford Linear Accelerator Center. The data span six orders of magnitude in cross section. Combinded statistical and systematic uncertainties in the cross section measurements ranged from 3.6% at low Q2 to 19% at high Q2. These data have been used to extract the proton magnetic form factor GMp(Q2) and Dirac form factor F1p(Q2) by using form factor scaling. The logarithmic falloff of Q4F1p expected from leading twist predictions of perturbative quantum chromodynamics is consistent with the new data at high Q2. Some nonperturbative and hybrid calculations also agree with our results.

2 data tables

Table 1

No description provided.

Table 2

Formfactor scaling assumes (Ge=Gm/mu).

Inclusive Muon Production in $e^+ e^-$ Annihilation with $\sqrt{s}$ = 7.3-GeV

Badtke, D.H. ; Barnett, B.A. ; Jones, L.H. ; et al.

Phys.Rev.Lett. 40 (1978) 827, 1978.

Inspire Record 134548 DOI 10.17182/hepdata.20890

We present results on charged multiplicity nch=2 and nch>2 muon events produced in e+e− collisions with 〈s12〉=7.3 GeV at 90° to the beams. The background-subtracted inclusive cross section for the nch=2 events is 10.2±5.4 pb/sr, in agreement with the expected contribution from the heavy lepton τ. The cross section for the nch>2 events is 19.0±6.5 pb/sr whereas we expect only 2.9 pb/sr from the τ, indicating that we may be seeing the weak decays of charmed mesons.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

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Differential cross-sections for the reactions $p + p \to D + \pi^+$ and $p + p \to D + \rho^+$ at 21-GeV/c

Low-energy differential cross-sections of pion proton (pi+- p) scattering. 2: Phase shifts at T(pi) = 32.7-MeV, 45.1-MeV, and 68.6-MeV

Low-energy differential cross-sections of pion proton (pi+- p) scattering. 1: The Isospin even forward scattering amplitude at T(pi) = 32.2-MeV and 44.6-MeV

Measurements of elastic electron - proton scattering at large momentum transfer

Inclusive Muon Production in $e^+ e^-$ Annihilation with $\sqrt{s}$ = 7.3-GeV

OBSERVATION OF INVERSE ELECTROPRODUCTION OF PIONS ON C-12 NUCLEUS AT 164-MeV PION ENERGY AND DETERMINATION OF F1(v) NUCLEON FORM-FACTOR

Measurement of Elastic electron Scattering from the Proton at High Momentum Transfer

STUDY OF REACTIONS WITH NEUTRON PRODUCTION IN P P AND P D COLLISIONS AT 1-GEV. (IN RUSSIAN)

Anti-p-p backward elastic scattering from 0.7 to 2.16 gev/c

Differential cross-sections for the reactions p p ---> d pi+ and p p ---> d rho+ in the energy range from 10 to 24 gev