2π0Mass Spectrum and Determination of the Spin of thef0Using

M. Wahlig

¹

,

E. I. Shibata

²

,

David Gordon

³

et al.

Abstract

LIFETIME 941 mentum, based upon this procedure, will affect the lifetime by less than 0.2%. VI. CONCLUSIONWe obtain a value for the mean life for K° -> w + ir"~ of n= (0.843±0.013)XlO-10 sec. This result is in agreement with the recently published values of the K%° lifetime given in Table I. T HE properties of the i^-ifi system have been studied using the interaction ir~+p -> ifl+ifl+n at 10 BeV/c. Two enhancements are observed in the TV 0 mass spectrum. The first stretches across the low end of the spectrum, from threshold to ~800 MeV. The second is identified as the f° meson. 1 The spin of the f° is determined, using a one-pion-exchange model, to be /= 2, in agreement with earlier indications. 2

2π0Mass Spectrum andδ00Shibata1, Frisch2, Wahlig3 1970Phys. Rev. Lett.21000View full textAdd to dashboardCite

“…8,9 The procedure for the kinematic reconstruction of the 2ir° events using only the directions of the four decay gammas is as described in our previous paper. 1 We have found that this procedure is equivalent to that of Carroll, Middlemas, and Williams, 10 who performed a similar experiment at lower incident momenta. 2 For our data both procedures give the same results.…”

“…In a previous paper, 1 we reported the observation of two enhancements in the 27r° mass spectrum as seen in the reaction TT" +p~ir° + ir° + n.…”

“…The second enhancement is broad, extending from threshold to ~1 GeV, and was not interpreted for two reasons: (a) Depending on then poorly known cross sections, possible backgrounds of up to 40% might have distorted the shape of our 27r° mass spectrum significantly; (b) our di-pion mass resolution was (and still is) not good enough to isolate the narrow peaks which were claimed to be in this mass region. 2 Now more information about background reactions is available, and more recent experiments 2 " 6 favor rather broad (several, hundreds of MeV wide) ITTT resonances or enhancements in this mass region, In this paper we report the results of a reanalysis of our data from Reaction (1). The 27r° mass spectrum is presented with explicit corrections for geometry and detection inefficiencies and with only a small amount (<9%) of background contamination..…”

“…Within statis- tics, events in the "low" mass region 0.27 ^M^ < 1 GeV are isotropic in the Treiman-Yang angle and in cosO ^ so we take J = 0 for this mass region. 1 ' 8 The 27T° mass spectrum, corrected for geometry and detection inefficiencies and cuts in analysis, is shown in Fig. 1(b).…”

Study of the Di-Pion from the Reactionπ−+p→n+π0+πFeldman1, Frati2, Gleeson3 et al. 1969Phys. Rev. Lett.12000View full textAdd to dashboardCite

“…4 " 6 Still others reported broad enhancements of various masses and widths. 7 " 10 The experiments studying 7r + 7r~" interactions are plagued with the proximity of the well-known pwave resonance, the p. Experiments attempting to study 77 0 7r° final states to date fall into two general categories: (1) those in which four y's from the decay of the two neutral pions are observed, affording a poor mass determination, and (2) those in which a good mass determination can be obtained as a residual of either the neutron time of flight or momenta measurements of the charged particles in the final state, thus offering a poor selection for isolating 2ir° states.…”