Blanar, G.
YLM
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Measurement and Analysis of the Reaction $\pi^- p \to \rho^0 n$ on a Polarized Target

The CERN-Munich collaboration Becker, H. ; Blanar, G. ; Blum, W. ; et al.
Nucl.Phys.B 150 (1979) 301-325, 1979.
Inspire Record 132603 DOI 10.17182/hepdata.34819

The reaction π − p→ π + π − n has been measured in a high-statistics experiment on a transversely polarized proton target at 17.2 GeV, and unexpectedly large nucleon polarization effects have been observed. Combining the results of this experiment with a measurement on a hydrogen target allows a model-independent partial-wave analysis in terms of the “nucleon transversity” amplitudes. Unique or at most twofold ambiguous solutions are obtained. In particular we find a high lower limit ( ⪆30% ) of the spin non-flip unnatural exchange amplitudes at low | t |. These amplitudes, interpreted as being due to the exchange of an object with the quantum numbers of the A 1 , have been assumed to be absent in previous analyses. In checking the consequences of this finding on the old results, we test the validity of the rank-two assumotions for the density matrix. We find a small but significant deviation, which shows the need for a new phase-shift analysis including the A 1 exchange contribution.

2 data tables
Table 1

MASS DEPENDENCE OF NORMALIZED T-CHANNEL MOMENTS SCALED TO 100 PCT POLARIZED PROTONS.

Table 2

T DEPENDENCE OF NORMALIZED T-CHANNEL MOMENTS IN THE RHO REGION SCALED TO 100 PCT POLARIZED PROTONS.


F0 (1270) Production in the Reaction pi- p --> pi+ pi- n at 12-GeV/c and 15-GeV/c

Alexander, G. ; Dagan, S. ; Gnat, Y. ; et al.
Nucl.Phys.B 131 (1977) 365-385, 1977.
Inspire Record 127448 DOI 10.17182/hepdata.35193

The production of the f 0 (1270) has been studied in the reaction π − p → π + π − n at 12 and 15 GeV/ c in the momentum transfer range 0.02 to 0.80 GeV 2 . Differential and total cross sections for the reaction π − p → f 0 n have been determined. The f 0 decay density matrix elements have been evaluated requiring all the matrix eigenvalues to be non-negative. The relative unnatural and natural parity exchange contributions to the f 0 production have been studied. The results are compared with a Regge exchange model formulated in terms of the pion and A 2 exchanges including cut contributions.

7 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Spin-Parity Analysis of the Diffractively Produced Low Mass n pi System in the Reaction pi+- p --> pi+- (n pi)+ at 16-GeV/c

The Aachen-Berlin-Bonn-CERN collaboration Otter, G. ; Rudolph, G. ; Wieczorek, H. ; et al.
Nucl.Phys.B 130 (1977) 349, 1977.
Inspire Record 119192 DOI 10.17182/hepdata.35244

The dominant partial waves of the diffractively produced N π system at low Nπ masses (⩽ 1.4 GeV) are determined in the reactions π ± p → π (N π ) at 16 GeV/ c . A satisfactory description of our data can only be obtained by strong contributions of both a 1 2 − S-wave and a 3 2 + P-wave, violating the Gribov-Morrison rule. Spin and parity of the diffractively produced states are found from the interference between diffraction and Δ (1236) production. The interference term is obtained by an isospin analysis.

2 data tables
Table 1

No description provided.

Table 2

<NUCLEON PION> MASS DEPENDENCE.


Properties of the inelastic k+ p reactions between 1.2 and 1.7 gev/c

Berthon, A. ; Montanet, L. ; Paul, E. ; et al.
Nucl.Phys.B 63 (1973) 54-92, 1973.
Inspire Record 83879 DOI 10.17182/hepdata.32479

The observation of 70 000 K 0 p π + events produced with K + incident momenta of 1.21, 1.29, 1.38 and 1.69 GeV/ c allows a detailed description of the production and decay of the Δ(1236) and K ∗ (892) resonances which dominate the K 0 p π + final state. No striking variations with energy are observed. The associated production of Δ and K ∗ near threshold shows striking similarities with the same production at higher energy.

22 data tables
Table 1

INCLUDING 1 PCT SYSTEMATIC ERROR ON CORRECTIONS.

Table 2

FIT 'A', ALLOWING FOR DELTA-K* INTERFERENCE (TWO OTHER FITS GIVEN IN PAPER).

Table 3

S-CHANNEL HELICITY FRAME.

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