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

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

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


A2- Production in the Reaction $\pi^- p \to K^- K^0_S p$ at 9.8-{GeV} and 18.8-{GeV}

The CERN-Munich collaboration Chabaud, V. ; Hyams, B. ; Jones, C. ; et al.
Nucl.Phys.B 145 (1978) 349-366, 1978.
Inspire Record 131631 DOI 10.17182/hepdata.34875

Results of two spark chamber experiments on A 2 − production in the reaction π − p → K − K S 0 (→ π + π − )p at 9.8 and 18.8 GeV are presented. Decay angular distributions and differential cross sections are given, and the energy dependence of the cross section σ [ π − p → A 2 − (→ K − K 0 )p] is compared with results from π − p → A 2 − (→ 3 π )p.

4 data tables

FITS WITH CONSTANT BACKGROUNDS. A TWO-PARAMETER LINEAR BACKGROUND GIVES MUCH LARGER ERRORS.

INTEGRATED OVER M(K AK) = 1.20 TO 1.42 GEV.

No description provided.

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Measurement of the Reactions $\bar{P} P \to \bar{\Lambda} \Lambda$, $\bar{p} p \to \bar{\Lambda} \Sigma^0$ and $\bar{P} P \to \bar{\Lambda}$ (Missing Mass) at 6-{GeV}

The CERN-Munich collaboration Becker, H. ; Blanar, G. ; Blum, W. ; et al.
Nucl.Phys.B 141 (1978) 48-64, 1978.
Inspire Record 130450 DOI 10.17182/hepdata.34946

None

3 data tables

OVERALL NORMALIZATION ERROR NOT INCLUDED. -TMIN IS 0.015 (0.023) GEV**2 FOR THE LAMBDA (SIGMA0) REACTION.

INCLUDING NORMALIZATION UNCERTAINTY IN ERRORS. USING EMPIRICAL FITS TO D(SIG)/DT FOR -T > 1.0 GEV**2.

No description provided.