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On the definition of the Delta mass and width

191   0   0.0 ( 0 )
 نشر من قبل Jambul Gegelia
 تاريخ النشر 2007
  مجال البحث
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In the framework of effective field theory we show that, at two-loop order, the mass and width of the Delta resonance defined via the (relativistic) Breit-Wigner parametrization both depend on the choice of field variables. In contrast, the complex-valued position of the pole of the propagator is independent of this choice.



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