@article{310cff0301b245f487704884daff7f60,
title = "Quenching of magnetic transitions and Δ(1232) degrees of freedom in nuclei: the 48Ca case",
abstract = "The quenching of M1 transitions is discussed within the framework of an effective magnetic transition operator renormalized by virtual Δ(1232)-hole excitations. This scheme is applied to the M1 transition from the ground state to the 10.23 MeV (1+) state in 48Ca, a case which appears to reveal a comparatively simple shell-model structure. It is demonstrated that a large fraction of the observed quenching of the B(M1) value can be related to Δ(1232) degrees of freedom in a way consistent with the quenching of Gamow-Teller transitions.",
author = "A. H{\"a}rting and W. Weise and H. Toki and A. Richter",
note = "Funding Information: Recently, the interest in the general role of polarization phenomena involving the A(1232) in the renormalization of spin\textasciitilde{}isospin-dependent transition operators in nuclei \textbackslash{}[1-5\textbackslash{}] has increased considerably, mainly because the suggested quenching of these operators in the long-wavelength limit has been observed systematically in magnetic transitions \textbackslash{}[6\textbackslash{}]a s well as Gamow-Teller (GT) resonances I7\textbackslash{}]. The common roots of both the magnetic spin-and GT-quenching mechanisms have been emphasized in a number of recent theoretical considerations for finite nuclei \textbackslash{}[8-12\textbackslash{}], thereby providing increasing evidence for the way in which A(1232) degrees of freedom operate in nuclei even at low energy and momentum transfers. In the present note we would like to concentrate on the case of the J \textasciitilde{}r = 1 +, T= 4, state ate x = 10.23 MeV in 48Ca. This state is excited by a strong M1 transition in backward (e, e') scattering \textbackslash{}[1 3\textbackslash{}]. The ground state of 48Ca has a fairly well closed proton Work supported in part by Deutsche Forschungsgemein-schaft.",
year = "1981",
month = sep,
day = "3",
doi = "10.1016/0370-2693(81)90122-2",
language = "English",
volume = "104",
pages = "261--264",
journal = "Physics Letters B",
issn = "0370-2693",
publisher = "Elsevier B.V.",
number = "4",
}