Electronic Resource
Springer
The European physical journal
33 (2004), S. 505-509
ISSN:
1434-6052
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract. The latest ${\rm\pi} N$ elastic scattering data are re-analysed to determine the coupling constant g c of the charged pion, using the dispersion relation for the invariant amplitude B (+ ). Depending on the choice of data-base, values $g^2_c/4{\rm\pi} = 13.80$ to 13.65 are obtained with errors of $\pm 0.12$ . The mass difference between charge states of $\Delta (1232)$ is $M^0 -M^{ + + } = 2.0 \pm 0.4$ MeV, close to twice the mass difference between neutron and proton. The difference in widths on resonance is $\Gamma^0 - \Gamma^{ + + } = 3.8 \pm 1.0$ MeV. One may account for a width difference of 4.5 MeV from phase space for decays and the extra channel $\Delta^0 \to \gamma n$ .
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1140/epjc/s2004-01666-y
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