1 6 O ct 2 00 7 Pion - nucleon P 33 and P 11 scatterings in the Lippmann - Schwinger approach
نویسنده
چکیده
We study the pion-nucleon P33 and P11 scattering, where the Delta and the Roper resonances are seen, respectively. We use the Lippmann-Schwinger equation extended to couple to a one-body state, and investigate nature of these resonances by taking and omitting a one-baryon state into account. We see validity and puzzle of the standard quark model interpretation, for the Delta and the Roper resonances, respectively.
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