AN AMPLITUDE ANALYSIS OF THE K+ K- SYSTEM PRODUCED IN THE REACTION PI- P ---> K+ K- N AT 10-GEV/C

The BARI-BONN-CERN-GLASGOW-LIVERPOOL-MILAN-VIENNA collaboration Costa, G. ; Donald, R.A. ; Edwards, D.N. ; et al.
Nucl.Phys.B 175 (1980) 402-434, 1980.
Inspire Record 159739 DOI 10.17182/hepdata.34458

We present results on an amplitude analysis of the K + K − system produced in the reaction π − p→K + K − n from threshold up to 2.2 GeV. The branching ratios of f 0 and f' to K K have been determined. In the low mass region of the K K system the observation of an S-wave enhancement at 1.3 GeV and the interference of the f 0 -A 2 -f' mesons are studied. We observe a 3 − structure in the mass region of 1.7 GeV which is consistent with g 0 production. With this interpretation the branching ratio g→ K K has been determined. Evidence for a new structure in the J p = 2 + wave around 1.8 GeV with a width of ∼200 MeV is presented.

2 data tables

HELICITY ZERO D-WAVE AMPLITUDE FITTED BY SUM OF BREIT-WIGNER RESONANCES. F 14 GIVES T-DEPENDENCE. ALSO EVIDENCE FOR 1.8 GEV STATE WITH 0.60 +- 0.13 MUB PRODUCTION CROSS SECTION.

FROM HELICITY ZERO F-WAVE AMPLITUDE ASSUMING PREDOMINANTLY G(1680)0 PRODUCTION. F 16 GIVES T-DEPENDENCE.


Study of the Reaction $\pi^- p \to N K^0_S K^0_S$ at 6.0-{GeV}/$c$ and 7.0-{GeV}/$c$

Polychronakos, V.A. ; Cason, N.M. ; Bishop, J.M. ; et al.
Phys.Rev.D 19 (1979) 1317, 1979.
Inspire Record 7273 DOI 10.17182/hepdata.24309

The KS0KS0 system produced in the reaction π−p→nKS0KS0 at 6.0 and 7 0 GeV/c has been studied utilizing the ANL 1.5-m streamer-chamber facility. A 400 000-photograph exposure yielded 5096 unweighted nKS0KS0 events. The cross section for this reaction was determined to be 9.6 ± 1.3 μb at 6.0 GeV/c and 8.7 ± 1.1 μb at 7.0 GeV/c. The decay angular distributions were parametrized in terms of moments of the spherical harmonics. The 〈Y40〉 moment was fitted to interfering Breit-Wigner amplitudes for the f and f′ mesons. Using this fit, the branching ratio R=Γ(f→KK¯)Γ(f→all) was found to be (2.3 ± 0.8)%. An energy-independent production-amplitude analysis revealed an enhancement in the S-wave amplitude near 1300 MeV. The properties of the S-wave enhancement are discussed and compared with those observed in other recent experiments. Extrapolated cross sections for the reaction ππ→KS0KS0 are presented. We find a cross section considerably below the S-wave unitarity limit in the S* region.

1 data table

FROM FIT TO D-WAVE (M=0) KS KS, CORRECTED FOR <K+ K-> AND <KL KL> DECAY MODES.