RESONANCE IN THE $lambda$$pi$ SYSTEM

Journal Article · Thu Dec 01 00:00:00 EST 1960 · Phys. Rev. Letters

DOI:https://doi.org/10.1103/PhysRevLett.5.520· OSTI ID:4126486

Alston, M; Alvarez, L W; Eberhard, P; Good, M L; Graziano, W; Ticho, H K; Wojcicki, S G

The reaction K/sup -/ + p -- LAMBDA /sup o/ + pi /sup +/ + pi /sup -/- was studied using 1.15-Bev/c K/sup -/ mesons in a 15-in. H/sub 2/ bubble chamber; of the total 255 events found, 141 were chosen to represent the reaction although 10 to l5% of them are estimated to be actually SIGMA /sup 0/ events. The energy distribution of the two pions on a Dalitz plot shows a nonuniform distribution of the points with peaks near 285 Mev. This distribution is consistent with a quasi-two-body reaction of the type K/sup -/ + p -Y*/sup s + pi ? (1), where Y* has a mass spectrum peaking at approximately 1380 Mev and breaks up in this way Y* plus or minus -- LAMBDA /sup oo/ + pi approximately ; 59 Y*+ /s++>s and 82 Y*/sup -/ events were observed, using the criterion that the high-momentum pion is the pion from reaction (1). Production angular distributions for Y*/sup +/ and Y*/sup -/ in the K-p rest system are given. An attempt was made without success to determine the spin of Y* by analyzing its angular momentum, the relations between its decay angle and the polarization of the resulting LAMBDA , and its anisotropy. The possibility that Y* corresponds to a resonance in pionhyperon scattering was studied by fitting a p-wave resonance formula to the pi LAMBDA data; the results were compared with those of Gell-Mann and Watson for the 3-3 resonance and found to be similar. (D.L.C.)

• Research Organization: Univ. of California, Berkeley
• NSA Number: NSA-15-006680
• OSTI ID: 4126486
• Journal Information: Phys. Rev. Letters, Journal Name: Phys. Rev. Letters Vol. Vol: 5
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ANGULAR DISTRIBUTION
ANISOTROPY
BUBBLE CHAMBERS
DALITZ PLOT
DECAY
DISTRIBUTION
ENERGY
ENERGY RANGE
GELL-MANN THEORY
HYDROGEN
INTERACTIONS
KAONS
LAMBDA PARTICLES
PHYSICS
PIONS
POLARIZATION
PROTONS
RESONANCE
SCATTERING
SOMMERFELD-WATSON THEORY
SPIN
WATSON LEMMA
Y*RESONANCES