Evidence for Unnatural Spin - Parity States of (K pi pi)0 in the Charge Exchange Reaction K- p --> (anti-K0 pi+ pi-) n

The Aachen-Berlin-CERN-London-Vienna & Athens-Democritos-Liverpool-Vienna collaborations Otter, G. ; Rudolph, G. ; Schmitz, P. ; et al.
Nucl.Phys.B 84 (1975) 333-341, 1975.
Inspire Record 90804 DOI 10.17182/hepdata.32131

A partial-wave analysis of the (K ππ ) 0 system produced in the charge exchange reaction K − p →( K 0 π + π − ) n has been made in the mass range 1.04 ⩽ M (K ππ ) < 1.56 GeV c data at 8, 10 and 16 GeV/ c . It was found that in about 2 3 of the cases, the (K ππ ) 0 system is produced in states of unnatural spin-parity, namely J P = 0 − and 1 + ; the rest is in the natural spin-parity state J P = 2 + state is consistent with being all K ∗ (1420). The unnatural spin-parity states are produced mostly (∼ 80% of the events) by natural parity exchange. The facts that unnatural spin-parity states are produced in this non-diffractive channel, with J P = 1 + dominant, and that the exchange responsible for their production is mostly of natural parity, are similar to what was found for the charged (K ππ ) − system in the diffractive reaction K − p→(K ππ ) − p. However, the absolute value and the energy dependence of the cross sections are very different in the two cases.

2 data tables

CORRECTED FOR UNSEEN AK0 DECAY MODES.

ACTUALLY CROSS SECTIONS FOR PRODUCTION IN MASS REGION 1.04 < M(AK0 PI+ PI-) < 1.56 GEV IN THE STATES JP = 1+, 2+ AND 0- RESPECTIVELY.


Study of lambda production in 10-GeV/c K- p interactions

The Aachen-Berlin-CERN-London-Vienna collaboration Bartsch, J. ; Kraus, G. ; Speth, R. ; et al.
Nucl.Phys.B 40 (1972) 103-124, 1972.
Inspire Record 75238 DOI 10.17182/hepdata.32927

Lambda production is studied in K − p interactions at 10.1 GeV/ c , where the dominant reaction is K − p → Λ + pions. General characteristics such as the distributions of the double differential cross section in the lab system, of the variable x = p L ∗ p max ∗ , of p ⊥ 2 and of the missing mass to the lambda are presented. Total cross sections for Λ production and for the various channels are given. Differential cross sections d σ d t , d σ d t′ and d σ d u′ are presented. Forward and backward peaks are observed in the d σ d t′ and d σ d u′ distributions, respectively. It is found that the exponential slope of these distributions decreases with increasing missing mass to the lambda and, for d σ d t′ , also for increasing multiplicity in the final state. The polarization of the lambdas is studied as a function of multiplicity, p L ∗ , (Λπ ± ) effective mass, t ′ and u ′. The forward lambdas show

2 data tables

No description provided.

POSSIBLE FORWARD DIP.


K- p elastic scattering at 10-GeV/c

The Aachen-Berlin-CERN-London-Vienna collaboration Bartsch, J. ; Deutschmann, M. ; Kraus, G. ; et al.
Nucl.Phys.B 29 (1971) 398-404, 1971.
Inspire Record 68635 DOI 10.17182/hepdata.33567

Results are presented on elastic scattering of 10.1 GeV/ c K − mesons on protons, based on a sample of 16 261 kinematically-fitted bubble-chamber events. The differential cross section is given over the | t |- range of 0.06 to 2.5 GeV 2 and is fitted with the expressions a e bt , A e Bt + Ct 2 and ( P e Qt + Re St ) over various intervals of t . The results are compared with those of other experiments at nearby energies. Upper limits of | α | < 0.28 and σ B < 0.4 μ b (both at a 90% confidence level) are given for the ratio of real to imaginary part of the forward-scattering amplitude and the backward-elastic-scattering cross section, respectively.

3 data tables

No description provided.

ERROR INCLUDES STATISTICAL ERROR AND ERROR IN TOTAL CROSS SECTION USED FOR NORMALIZATION. EXTRAPOLATION OF D(SIG)/DT TO T=0 PROVIDES ABOUT 0.5 PCT UNCERTAINTY.

NO BACKWARD EVENTS OBSERVED. LARGEST ANGLE EVENT SEEN WAS AT 64 DEG (-T = 2.33 GEV**2).