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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
Table 1

No description provided.


K+ p and k+ d total cross-sections in the momentum range 0.57-1.16 gev/c

Bowen, T. ; Jenkins, E.W. ; Kalbach, R.M. ; et al.
Phys.Rev.D 7 (1973) 22-26, 1973.
Inspire Record 82624 DOI 10.17182/hepdata.22144

K+p and K+d total cross sections were measured in the momentum range 0.57-1.16 GeV/c using a secondary, separated kaon beam of the Lawrence Berkeley Laboratory Bevatron and conventional transmission-counter techniques. No evidence was found for structure in the cross section of either reaction as previously indicated near 0.7 GeV/c.

1 data table
Table 1

No description provided.


K- d interactions at 5.5 gev/c - sigma-+ pi+- pi-(pi0), sigma- k+, k- and k- pi- p final states in which a hyperon is produced

Kropac, W. ; Ammar, R. ; Davis, R. ; et al.
Phys.Rev.D 7 (1973) 585-599, 1973.
Inspire Record 82572 DOI 10.17182/hepdata.22114

The results presented in this paper are obtained from an analysis of bubble-chamber pictures of K−d interactions at an incident K− momentum of 5.5 GeV/c. Generally, the quasitwo-body final states are produced peripherally, with a small backward peak occurring in some of the final states. The final states Σ−ω, Σ−ρ0, and Σ−φ appear to be produced primarily by vector-meson exchange. In the final state Λ(1520)π− the decay distributions of the Λ(1520) hyperon are found to be consistent with a vector-exchagne production process with M2 coupling at the nucleon vertex. The predictions of the independent-quark model and of other symmetry schemes, namely that the forward cross sections for Σ−ρ0, Σ−ω, Σ−φ production be in the ratios 1: 1: 2, are not inconsistent with our experimental values.

5 data tables
Table 1

No description provided.

Table 2

FRACTIONAL FORWARD HYPERON CROSS SECTION AFTER BACKGROUND SUBTRACTION.

Table 3

No description provided.

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Sigma+ polarization in pi+ n ---> k0 sigma+ from 1.1 to 2.4 gev/c

Davies, D.W. ; Abolins, M.A. ; Dahl, O.I. ; et al.
Phys.Rev.D 7 (1973) 3546-3548, 1973.
Inspire Record 82052 DOI 10.17182/hepdata.22133

We observe an energy-dependent polarization of the Σ+ produced in the reaction π+n→K0Σ+ at incident beam momenta between 1.1 and 2.4 GeV/c. These data form a significant source of information on the Σ− polarization in the charge-symmetric reaction π−p→K+Σ−.

2 data tables
Table 1

INTEGRATED OVER ALL PRODUCTION ANGLES.

Table 2

No description provided.


Analysis of two-prong events in proton proton interactions at 6.6 gev/c

Colton, E. ; Ming, Ma.Z. ; Smith, G.A. ; et al.
Phys.Rev.D 7 (1972) 3267-3295, 1972.
Inspire Record 82060 DOI 10.17182/hepdata.22134

A detailed analysis is presented of the reactions pp→pp,pp→ppπ0 and pp→pπ+n. The production cross sections are found to be 11.47 ± 0.33 mb, 2.54 ± 0.16 mb, and 5.73 ± 0.35 mb, respectively. The t dependence of elastic scattering can be described by the form e7.9t over the range 0.05<−t<0.50 GeV2. The single-particle distributions for the single-pion production processes are presented. Further detailed analyses are presented which demonstrate that pion-exchange phenomenology, both elementary and Reggeized, can account for the gross features of the peripheral pp→pπ+n data for M(pπ+)<2.4 GeV. Isospin-12 isobars are produced by some other processes in the channel pp→pN*+, especially when the invariant mass of the pion with the unrelated proton is large. We discuss the properties of these isobars.

6 data tables
Table 1

No description provided.

Table 2

FITTED OVER 0.05 < -T < 0.5 GEV**2.

Table 3

No description provided.

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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
Table 1

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


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.


Measurement of sigma(tot) in proton proton scattering in pure spin states

Parker, E.F. ; Ratner, L.G. ; Brown, B.C. ; et al.
Phys.Rev.Lett. 31 (1973) 783-786, 1973.
Inspire Record 83779 DOI 10.17182/hepdata.21350

An experiment was done using the new accelerated polarized proton beam at the Argonne National Laboratory zero-gradient synchrotron and a polarized proton target. The total cross section for proton-proton scattering at 3.5 GeV/c was measured in the spin states ↑↑ and ↑↓ perpendicular to the beam direction. The two cross sections were found to be equal within the experimental error of ±5%.

1 data table
Table 1

TOTAL CROSS SECTION DIFFERENCE FOR PURE TRANSVERSE SPIN STATES.


Recoil-proton polarization in neutral-pion photoproduction and in proton Compton scattering

Deutsch, M. ; Golub, L. ; Kijewski, P. ; et al.
Phys.Rev.Lett. 29 (1972) 1752-1755, 1972.
Inspire Record 84562 DOI 10.17182/hepdata.21426

We have measured the polarization of the recoil proton in the reactions γp→π0p and γp→γp for incident photon energies between 3 and 7 GeV, and t values from -0.2 to -0.65 GeV2. The polarization in neutral-pion production varies from 0 to -1 over this range. Contrary to expectation, it does not agree completely with the polarized-target asymmetry.

1 data table
Table 1

No description provided.


Large angle pi+ p and k+ p elastic scattering at 13.8 gev/c

Rubinstein, R. ; Cornillon, P. ; Grindhammer, Guenter ; et al.
Phys.Rev.Lett. 30 (1973) 1010-1012, 1973.
Inspire Record 84502 DOI 10.17182/hepdata.21417

The differential cross section for π+p elastic scattering has been measured at 13.8 GeVc for 0.7<|t|<3.8(GeVc)2. The cross section is found to be equal to that previously obtained for π−p elastic scattering, except in the region |t|=2.8 (GeVc)2, where the π+p data do not show the prominent dip observed in π−p scattering. Data have also been obtained for 13.8−GeVc K+p elastic scattering for 0.8<|t|<2.2 (GeVc)2.

2 data tables
Table 1

No description provided.

Table 2

No description provided.