Marketin, Tomislav and MartinezPinedo, Gabriel and Paar, Nils and Vretenar, Dario (2012) Role of momentum transfer in the quenching of GamowTeller strength. Physical Review C, 85 (5). pp. 543139. ISSN 05562813

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Abstract
Differential cross sections for the (p, n) and (n, p) reactions on 90Zr over the interval of 0–50MeV excitation energy were used to determine the corresponding GamowTeller (GT) strengths, and the resulting quenching factor is ≈0.9 with respect to the Ikeda sum rule. In this procedure the contribution of the isovector spin monopole (IVSM) strength was subtracted from the total strength without taking into account the interference between the GT and the IVSM modes. Purpose was to determine the quantitative effect of the IVSM excitation mode on the L=0 strength in chargeexchange reactions on several closedshell nuclei and the Sn isotopic chain. The fully consistent relativistic HartreeBogoliubov model plus protonneutron relativistic quasiparticle randomphase approximation (pnRQRPA) are employed in the calculation of transition strength in the β− and β+ channels. The inclusion of the higherorder terms, that include the effect of finite momentum transfer, in the transition operator shifts a portion of the strength to the highenergy region above the GT resonance. The total strength is slightly enhanced in nuclei with small neutrontoproton ratios but remains unchanged with increasing neutron excess. Terms that include momentum transfer in the transition operator act mostly to shift the strength to high excitation energies but hardly affect the total strength. Based on the strength obtained using the full L=0 transition operator in the pnRQRPA calculation, we have estimated the impact of the IVSM on the strength measured in the chargeexchange reactions on 90Zr and found that the data are consistent with the Ikeda sum rule.
Item Type:  Article 

Keywords:  nuclear energy density functional, GamowTeller strength, quasiparticle random phase approximation 
Date:  May 2012 
Subjects:  NATURAL SCIENCES > Physics > Nuclear Physics 
Additional Information:  Copyright (2012) by the American Physical Society. 
Divisions:  Faculty of Science > Department of Physics 
Project code:  11911910051010 
Publisher:  American Physical Society 
Depositing User:  Gordana Stubičan Ladešić 
Date Deposited:  09 Jun 2014 12:56 
Last Modified:  23 Feb 2016 16:08 
URI:  http://digre.pmf.unizg.hr/id/eprint/2156 
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