Date

A formation study of n anti-n interactions between 1.51 and 2.90 gev/c. i. topological and reaction cross-sections

Eastman, P.S. ; Ming, Ma.Z. ; Oh, B.Y. ; et al.
Nucl.Phys.B 51 (1973) 29-56, 1973.
Inspire Record 84299 DOI 10.17182/hepdata.32706

A systematic study of p p and p d topological and reaction cross sections between 1.51 and 2.90 GeV/ c has been completed. The data have been analysed in relation to the three known structures at c.m. N N energies of 2190, 2350 and 2375 MeV. The data suggest that four- and six-pion annihilations of antiprotons on neutrons may be the source of the 2350 MeV effect. Further data below 1.60 GeV/ c are required to verify this tentative conclusion.

3 data tables

No description provided.

INCLUDING 3 PCT SYSTEMATIC ERROR.

No description provided.


A formation study of n anti-n interactions between 1.09 and 3.45 gev/c. (iv)-features of annihilations into k anti-k and pi mesons

Oh, B.Y. ; Eastman, P.S. ; Ming, Ma.Z. ; et al.
Nucl.Phys.B 63 (1973) 1-27, 1973.
Inspire Record 83880 DOI 10.17182/hepdata.32487

Final state resonance production and single particle momentum spectra are presented for p p annihilations into K K and π's between 1.09 and 3.45 GeV/ c . Resonance production generally agrees with the Lamb statistical model. Momentum spectra of K's and π's are independent of incident energy, while the mean multiplicity increases in proportion to the c.m. energy, supporting the annihilation model of Jacob and Nussinov.

2 data tables

THESE CROSS SECTIONS WERE GIVEN IN DETAIL IN B. Y. OH ET AL., NP B51, 57 (1973).

No description provided.


Vector-meson electroproduction at high q-squared

Ahrens, L. ; Berkelman, Karl ; Brown, G.S. ; et al.
Phys.Rev.Lett. 31 (1973) 131-133, 1973.
Inspire Record 84487 DOI 10.17182/hepdata.47133

We have measured ρ0, ω (combined) and ϕ electroproduction over a range of virtual-photon four-momentum Q2 from 0.4 to 2.2 GeV2 and for photon energies ν from 2.7 to 8.6 GeV. We find that the slope of the t (momentum transfer) dependence of the ρ0 and ω forward peak decreases with increasing Q2 to less than half of the photoproduction slope.

1 data table

The cross section for virtual photon are derived from E- P cross section bydividing on the virtual-photon flux factor.


Observation of three narrow neutral mesons in the vicinity of 950 mev

Cheshire, D.L. ; Jacobel, R.W. ; Lamb, R.C. ; et al.
Phys.Rev.Lett. 28 (1972) 520-523, 1972.
Inspire Record 75535 DOI 10.17182/hepdata.21441

In a scintillation-counter experiment, we have observed two narrow, neutral mesons in addition to the well-established η′ (958) in the reaction π−p→M0n at 2.4 GeVc. We observe a mass of 940.5 ± 1.7 MeV, Γ<10.4 MeV for the M0(940), and a mass of 962.9 ± 1.7 MeV, Γ<5.9 MeV for the δ0.

1 data table

CROSS SECTION OVERALL UNCERTAINTY (APART FROM ETA PRODUCTION) ABOUT 30 PCT.


THE ANGULAR DISTRIBUTION OF THE PHOTOPRODUCTION OF POSITIVE PIONS FROM HYDROGEN BY 187-MeV GAMMA RAYS

Lewis, G.M. ; Leith, David W.G.S. ; Thomas, D.L. ; et al.
Nuovo Cim. 27 (1963) 384, 1963.
Inspire Record 8502 DOI 10.17182/hepdata.37716

The differential cross-section for π+ photoproduction from hydrogen by γ-rays of laboratory energy 187 MeV has been measured at four angles. Two identical counter systems, designed to detect low energy pions unambiguosly in intense electron and γ-ray backgrounds, were used in conjunction with a cylindrical liquid hydrogen target, of very low boil-off rate. The cross-sections at laboratory angles of 39.2°, 66.7°, 111.6°, and 134° are 7.49±0.47, 8.10±0.57, 8.36±0.61 and 9.54±0.61, ·10−30cm2/sr, respectively, where the assigned errors refer only to the relative values. The absolute cross-sections are in substantial agreement with the dispersion theory and confirm the front to back asymmetry.

1 data table

No description provided.