摘要:

The K&pgr; scattering forM(K&pgr;) < 1 GeVhas been studied in the reactionK+p ⇒ &Dgr;++K+&pgr;−at 12 GeV/c incident K+momentum. Both the moments of the K&pgr; angular distribution and the K&pgr; cross section are extrapolated to the pion pole, and the results are used in a partial wave analysis. For the s wave we have done both an energy‐independent and an energy‐dependent partial wave analysis. We find that only the so‐called “down” solution is compatible with our data; that is, a phase shift &dgr;01slowly increasing from 20° at 800 MeV to 60° at 1000 MeV. No evidence for an s‐wave resonance near the K*(890) mass is found, although a resonance with&Ggr; < 7 MeVcannot be excluded by the data. The “down” solution is well represented by an effective range formula witha01 = − 0.33 ± 0.05, in good agreement with a current algebra calculation.

ISSN:0094-243X    

DOI:10.1063/1.2947102

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The determination of the low energy &pgr;&sngbnd;&pgr; phase shifts from the decaysK± ⇒ &pgr;+&pgr;−e±&ngr;is discussed. Results of the University of Pennsylvania Ke4experiment are presented. These results are compared with higher energy data on the &pgr;&sngbnd;&pgr; phase shifts and with the results of another Ke4, experiment.

ISSN:0094-243X    

DOI:10.1063/1.2947107

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

We perform an energy independent &pgr;&pgr; phase shift analysis in the energy range440 < M&pgr;&pgr; < < 1400 MeVusing high statistics&pgr;−p⇒&pgr;−&pgr;+ndata at 17.2 GeV/c. The method is based on an amplitude analysis of the production process and the extrapolation of the dominant &pgr; exchange amplitudes to the &pgr; exchange pole. We consider the phase shift ambiguities and study ways of selecting the physical solution. We determine the parameters of the &rgr; and f resonances. We find anI = 0S wave resonance under the f and we comment on the properties of the S*resonance near the KKthreshold.

ISSN:0094-243X    

DOI:10.1063/1.2947126

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A study has been done of&pgr;− − &pgr;+and&pgr;− − &pgr;−scattering using the reactions&pgr;− + p ⇒ &pgr;− + &pgr;+ + nand&pgr;− + p ⇒ &pgr;− + &pgr;− &pgr; &Dgr;++. The elastic scattering cross section shows a steady decrease from 120 mb (for&pgr;− − &pgr;+) in the region of the &Vrgr; to 1 – 2 mb in the 2–4 GeV/c2mass range. Estimates of the total cross section are also made using the optical theorem. Both the&pgr;− − &pgr;+and&pgr;− − &pgr;−cross sections seem to be about 15 mb in the high mass region.

ISSN:0094-243X    

DOI:10.1063/1.2947127

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

We discuss how zeros in &pgr;&pgr; scattering relate various dynamical aspects of the scattering amplitude. In particular, we consider the way in which many differing roles, such as the Legendre zeros of resonances, double‐pole‐killing zeros, the high energy crossover zero and the Adler zero, can be played by the same zero contour. We emphasize that the study of the scattering amplitude is essentially one of looking at zeros travelling across the Mandelstam plane.

ISSN:0094-243X    

DOI:10.1063/1.2947128

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Results of an energy‐dependent phase‐shift analysis for &pgr;&pgr; scattering between 900 and 1120 MeV mass are presented using data of the reactions&pgr;±p ⇒ &pgr;±&pgr;+nand&pgr;−p ⇒ K+K−n. TheI = 0S‐wave becomes highly inelastic at KKthreshold and accounts for the structure in the &pgr;&pgr; system. A zero effective range approximation for the S‐ wave leads to a pole of the S‐matrix which is located on the second Riemann sheet at(1012 ± 6) − i(16 ± 5) MeV.

ISSN:0094-243X    

DOI:10.1063/1.2947097

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A few observations are made relating to: various inelastic channels which couple to the &pgr;&sngbnd;&pgr; system; coupled channel analysis especially near the KKthreshold; the &pgr;‐exchange production mechanism and absorption. Finally, a method for measuring the &pgr;&sngbnd;&pgr; total cross section from the inclusive reaction&pgr;+p ⇒ &Dgr;++ + anythingis discussed.

ISSN:0094-243X    

DOI:10.1063/1.2947098

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Multiparticle states derived from &pgr;&pgr; and K&pgr; scattering are discussed and the techniques for analysis of 3 body final states are described. The role that inelastic reactions play in determination of resonance parameters is investigated and the conclusion reached that they only provide information on the specific inelastic channel couplings. Thus the identification of resonances coupling to &pgr;&pgr; or K&pgr; systems is most easily made by observation of the elastic and charge exchange reactions.

ISSN:0094-243X    

DOI:10.1063/1.2947099

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

The determination of the two‐body production amplitudes forY=1exchange reactions is discussed. The pseudoscalar production line reversed reactionsK−n ⇒ &pgr;−Lgr;and&pgr;−p ⇒ K0&Lgr;; the vector‐meson production reactionsK−p ⇒ (&ohgr;,&Jgr;)&Lgr;and&pgr;−p ⇒ K*0&Lgr;; the reactionK−p ⇒ &pgr;−Y*+(1385); and the photoproduction reaction&ggr;p ⇒ K+&Lgr;are examined. Quark model, SU(3), and VDM comparisons are made and the EXD nature of the K**and K*Regge exchanges explored. In addition the behavior of the unnatural parityY=1exchanges (K, KB, KA) are investigated

ISSN:0094-243X    

DOI:10.1063/1.2947100

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Direct channel or absorption effects are first considered for &pgr; exchange reactions, and in particular for&pgr;N ⇒ &rgr;N. The discussion is then restricted to nondiffractive pseudoscalar‐meson baryon scattering reactions, where only two helicity amplitudes define the scattering process. The 6 GeV/c &pgr;p amplitude analyses are reviewed; energy dependences of various features of the data are then studied to obtain a qualitative understanding of the energy trends of the helicity amplitudes. The relation of these results to &pgr;&pgr; analyses is discussed.

ISSN:0094-243X    

DOI:10.1063/1.2947101

出版商:AIP    

年代:1973

数据来源: AIP