Measurement of Resonance Productions in the Reactions $\gamma \gamma \to \pi^0 \pi^0$ and $\gamma \gamma \to \pi^0 \eta$

The JADE collaboration Oest, T. ; Olsson, J. ; Allison, J. ; et al.
Z.Phys.C 47 (1990) 343-352, 1990.
Inspire Record 295180 DOI 10.17182/hepdata.15242

Resonance production in the γγ reactionse+e−→e+e+e−π0π0 ande+e−π0η has been studied with the JADE detector at PETRA. The decay widths into γγ of thef2(1270),a0(980) anda2(1320) were measured to be\(\Gamma _{\gamma \gamma } (f_2 (1270)) = 3.19 \pm 0.09_{ - 0.38}^{ + 0.22} \) Kev,Γλλ(a0(980))=0.28±0.04±0.10 KeV/BR(a0(980)→π0η) andΓλλ(a2(1320))=1.01±0.14±0.22KeV. For thef0(975) andf4(2050) upper limits of the widths were obtained,Γλλ(f0(975))<0.6 KeV, andΓλλ(f4(2050))<1.1 KeV, both at the 95% C.L. Assuming that the spin 0 background under thef2(1270) is small, thef2(1270) was found to be produced exclusively in a helicity 2 state. The helicity 0 contribution is <15% at the 95% C.L. The cross section forλλ→π0π0 in the mass range 2.0–3.5 GeV/c2 was measured for the first time. Since the cross section forλλ→π+π− is a factor ∼2 larger, ππ production in this range can be interpreted as taking place via isospin 0 production.

6 data tables

Cross section for ABS(COS(THETA*)) < 0.3.

Cross section under assumptions of spin 2, helicity 2 production.

Cross section under assumption of spin 0 production.

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MEASUREMENT OF ASYMMETRY IN CROSS-SECTION OF GAMMA P ---> P PI0 REACTION IN THE RESONANCE REGION. (IN RUSSIAN)

Avakian, R.O. ; Avetisian, A.E. ; Bagdasaryan, A.S. ; et al.
Yad.Fiz. 38 (1983) 1196-1198, 1983.
Inspire Record 200187 DOI 10.17182/hepdata.17731

None

1 data table

Axis error includes +- 0.0/0.0 contribution (?////DUE TO ERRORS IN PHOTON POLARIZATION).


A Study of K0 p Charge Exchange Scattering from 0.6-GeV/c to 1.5-GeV/c

Armitage, J.C.M. ; Aston, D. ; Duerdoth, I.P. ; et al.
Nucl.Phys.B 123 (1977) 11-46, 1977.
Inspire Record 118913 DOI 10.17182/hepdata.35426

An experiment is described to measure the differential cross section for the charge-exchange reaction K 0 p → K + n from 0.6 to 1.5 GeV/ c incident kaon momentum in the angular range −0.65 < cos θ ∗ < 0.85 The calibration of the kaon beam by observation of K S 0 regeneration is also described. The differential cross sections are fitted with Legendre polynomials and compared with those from the time-reversed reaction using deuterium targets. Qualitative conclusions are drawn on the behaviour of particular charge-exchange amplitudes.

2 data tables

No description provided.

FITTED VALUES OF DIFFERENTIAL CROSS SECTION LEGENDRE COEFFICIENTS (4 TIMES USUAL DEFINITION).