Electromagnetic Decay of theY0*(1520)

Abstract

erable scatter in the estimates of both the cross section for uN-^fN and the/° width. Since we do not wish to discuss or evaluate these discrepancies, we will simply take as a rough guess from the available data that a(7r""/)-*/°n-7r'^7r~"n)~120 /ib at 5 GeV/c (with the same cuts used for the Air data). This gives^ a branching ratioIn order to get a rough idea of the Ul dependence of the cross section we have carried out a similar analysis on the data without a U! cut. We find iVpoo = 69±21 events (all t), in good agreement with the t distribution observed for /° We have not discussed the possibility that the observed peak at 1.27 GeV could be the Z)(1285). We note however that the width and \t\ distribution of our peak are in apparent disagreement with that quoted for the D.^^ We would also require that the spin of the D be ^2.We wish now to comment briefly on the narrow peak at w 47^ ~ 1.42 GeV. The present data are clearly not sufficient to establish the presence of a resonance. If we suppose that the peak is not a statistical fluctuation, the data (Fig. 3) suggest that it may also have J^ = 2"*", and may therefore possibly correspond to the enhancement observed by Beusch et al.^^ in K^^Kj^.

Erratum: Radiative decays of theΣ0(1385)andΛ(1520)Taylor1, Mutchler2, Adams3 et al. 2005Phys. Rev. C11380View full textAdd to dashboardCite

“…The error on the full width is included in the systematic error for Γ(Λγ). The Λ(1520) result is compatible with the Mast et al result [16] and the Antipov et al result [18] but disagrees with the Bertini et al result [17]. Together, our result and those of Mast et al and Antipov et al exclude the bag models listed in Table I.…”

“…For the Λ(1520) the exponential slope for the t-dependence was 2.0 GeV −2 . The angular distribution for the radiative decay of the Λ(1520) in its rest frame was taken to be proportional to 5 − 3 cos 2 θ according to the result obtained by Mast, et al [16]. The same distribution was used for the Σπ channels and for the Σ(1385) decays.…”

“…The results are tabulated in Table I. The Λ(1520) → Λγ transition has been measured by Mast et al [16] using a K − beam with a liquid-hydrogen bubble chamber, by Bertini et al [17] (unpublished) with a liquid-hydrogen target viewed by a NaI detector, and by Antipov et al [18] using a high-energy proton beam on carbon and copper targets. Antipov et al measured the K + , p and π − in a magnetic spectrometer and detected the decay photons using an electromagnetic calorimeter.…”

Radiative decay of theΛ*(1520)

“…[39]) but is extrapolated from Γ(Λ * → γΛ) by using SU (3) arguments in Ref. [37]. Summarizing, the experimental situation is far from being clear.…”

First observation of the isospin violating decayJ/ψ→ΛΣ¯0+c.c.

“…For example, predictions for the radiative decay Λ(1520) → γΛ have been made in a number of frameworks including: a non-relativistic quark model (NRQM) [6,7]; a relativistic constituent quark model (RCQM) [8]; the MIT bag model [6]; the chiral bag model [9]; an algebraic model of hadron structure [10]; and a chiral quark model (χQM) [11]. In contrast, experimental measurements have been sparse [12][13][14][15]. The radiative decays Λ * → γΛ can be studied with J/ψ → γΛΛ events.…”