Date

Search for structure in pi- p ---> lambda k0 at sigma k threshold

Nelson, B. ; Knasel, T.M. ; Lindquist, J. ; et al.
Phys.Rev.Lett. 31 (1973) 901-904, 1973.
Inspire Record 83771 DOI 10.17182/hepdata.21338

We have measured the cross section, the angular distribution, and the Λ polarization for the reaction π−p→ΛK0. A spark-chamber spectrometer was used to collect 8400 ΛK0 events at fourteen beam momenta near ΣK threshold. Our data do not show the prominent cross-section enhancement suggested by some previous experiments. However, detailed structure in the cross section and the angular distribution agrees well with a simple model which includes a cusp effect at ΣK threshold.

3 data tables

No description provided.

BACKWARD-FORWARD PRODUCTION ASYMMETRY.

AVERAGE LAMBDA POLARIZATION.


Measurement of the Slope of the Diffraction Peak for Elastic pp Scattering from 8-GeV to 400-GeV.

Bartenev, V. ; Kuznetsov, A. ; Morozov, B. ; et al.
Phys.Rev.Lett. 31 (1973) 1088-1091, 1973.
Inspire Record 81722 DOI 10.17182/hepdata.21381

The slope b(s) of the forward diffraction peak of p−p elastic scattering has been measured in the momentum-transfer-squared range 0.005≲|t|≲0.09 (GeV/c)2 and at incident proton energies from 8 to 400 GeV. We find that b(s) increases with s, and in the interval 100≲s≲750 (GeV)2 it can be fitted by the form b(s)=b0+2α′lns with b0=8.23±0.27, α′=0.278±0.024 (GeV/c)−2.

1 data table

MOMENTUM BINS ARE APPROX 20 GEV WIDE CENTRED AT THE GIVEN PLAB EXCEPT FOR THE 9 AND 12 GEV POINTS WHICH HAVE WIDTHS OF APPROX 1 AND 4 GEV RESPECTIVELY.


Measurement of polarization pn pi- p ---> pi0 n at 3.5 and 5.0 gev/c

Hill, D. ; Koehler, P. ; Novey, T. ; et al.
Phys.Rev.Lett. 30 (1973) 239-242, 1973.
Inspire Record 84552 DOI 10.17182/hepdata.21395

The polarization parameter P(t) for the reaction π−p→π0n has been measured at 3.5 and 5.0 GeV/c over the range 0.2<~−t<~1.8 (GeV/c)2. The two γ rays from the π0 decay were detected in a large lead-glass hodoscope. The results agree with the positive polarization values found in earlier Argonne National Laboratory data at −t<0.35 (GeV/c)2. P(t) drops to a small value near t=−0.6 (GeV/c)2 and remains the same out to t=−1.8 (GeV/c)2.

1 data table

DATA POINTS MEASURED FROM SMALL GRAPH.


Hadron Production by electron positron annihilation at 4-GeV center-of-mass energy

Litke, A. ; Hanson, G. ; Hofmann, A. ; et al.
Phys.Rev.Lett. 30 (1973) 1189-1192, 1973.
Inspire Record 85252 DOI 10.17182/hepdata.21416

We have measured the total cross section for electron-positron annihilation into three or more hadrons, with at least two charged particles in the final state. The measurement was made at a center-of-mass energy of 4 GeV with a 2π−sr nonmagnetic detector. With 88 events detected, we obtain a model-independent lower limit on the hadron production cross section of 9.6 ± 1.4 nb; a calculation of detection efficiency based on invariant phase-space production of pions leads to a total cross section of 26 ± 6 nb. This cross section is 4.7 ± 1.1 times the theoretical total cross section for e+e−→μ+μ−. The average charged multiplicity is n¯=4.2±0.6.

1 data table

No description provided.


Recoil-proton polarization in neutral-pion photoproduction between 1000 and 1800 mev

Tanaka, N. ; Castro, M.M. ; Milburn, Richard H. ; et al.
Phys.Rev.D 8 (1973) 1-8, 1973.
Inspire Record 81985 DOI 10.17182/hepdata.22112

Measurements are presented of the recoil-proton polarization for π0 photoproduction angles near 64° in the c.m. system. The steep angular dependence observed by others at lower energies persists to at least 1500 MeV, and the polarization crosses through zero near 63° over the entire 900-1600-MeV energy interval. Summary fits are made to available recoil-proton polarization data, 950-1250 MeV, and are found to require terms of order cos3θ, but no higher.

1 data table

Axis error includes +- 0.0/0.0 contribution (?////).


Pi0 photoproduction from neutrons

Osborne, A.M. ; Brownam, A. ; Hanson, K. ; et al.
Phys.Rev.Lett. 29 (1972) 1621-1624, 1972.
Inspire Record 84571 DOI 10.17182/hepdata.21431

We have measured the ratio of the cross section for γ+n→π0+n to the cross section for γ+p→π0+p at 4.7 and 8.2 GeV. The measurements were made by detecting the recoil nucleons in coincidence with the decay γ rays of the π0's produced from a deuterium target. At 4.7 GeV the cross-section ratio, R≡σ(γ+n→π0+n)σ(γ+p→π0+p), is less than 1.0 at low t, with an indication of a dip at about t=−0.7(GeVc)2, and rises to 1.0 at high t. The ratios at the higher energy have less structure and are uniformly closer to 1.0.

2 data tables

No description provided.

No description provided.


Experimental study of the reaction $\pi^- p \to \Lambda K^0$ at beam momenta between 930 and 1130 MeV/c

Knasel, T.M. ; Lindquist, J. ; Nelson, B. ; et al.
Phys.Rev.D 11 (1975) 1-13, 1975.
Inspire Record 107188 DOI 10.17182/hepdata.24916

We have used an optical spark-chamber spectrometer to perform a systematic study of the reaction π−p→ΛK0 at beam momenta between 930 and 1130 MeV/c. The cross section, angular distribution, and Λ polarization have been measured. We present our complete data from a sample of 11 400 events along with Legendre polynomial coefficients for the angular distributions. No striking cross-section enhancement at ΣK threshold is observed, but there is evidence for a small cusp effect. A simple model which takes account of the ΣK channel provides a good fit to our data.

4 data tables

No description provided.

No description provided.

No description provided.

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Two-body final states in k- p interactions at 14.3 gev/c

Miller, R.J. ; Paler, K. ; Phelan, J.J. ; et al.
Lett.Nuovo Cim. 6S2 (1973) 491-496, 1973.
Inspire Record 86301 DOI 10.17182/hepdata.37298

None

4 data tables

No description provided.

No description provided.

AVERAGED OVER ALL PRODUCTION ANGLES.

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Polarization measurement of antiproton scattered elastically from proton at 220 mev

Ohsugi, T. ; Fujisaki, M. ; Kaneko, S. ; et al.
Nuovo Cim.A 17 (1973) 456-463, 1973.
Inspire Record 87646 DOI 10.17182/hepdata.37771

The polarization of scattered antiproton in\(\bar pp\) elastic scattering has been measured at the kinetic energy of 220MeV by means of double scattering in a bubble chamber. The polarizations obtained are 0.28±0.11, 0.46±0.12, 0.51±0.19 and 0.38±0.31 at the scattering angles 28°, 42°, 56° and 73° in the c.m. system, respectively. These results do not seem to be in good agreement with a prediction given by Bryan and Phillips. We have also compared these data with a modified diffraction model.

1 data table

POLARIZATION ASSUMED POSITIVE.


Two-prong fitted channels at 11.7 gev/c

Evans, D. ; Neat, K. ; Caso, C. ; et al.
Nuovo Cim.A 16 (1973) 299-314, 1973.
Inspire Record 87004 DOI 10.17182/hepdata.37784

A sample of 43000 two-prong events obtained at a momomentum of 11.7 GeV/c is used to determine the cross-sections of the fitted channels, and to study the reaction π+p→π+pπ0. We investigate in particular the quasi-two-body channels π0Δ++ and ρ+p.

6 data tables

No description provided.

No description provided.

No description provided.

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