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arXiv 1602.06134nucl-thastro-ph.SR
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准粒子无规相近似下铬同位素的自旋-同位旋跃迁

Spin-isospin transitions in chromium isotopes within the quasiparticle random phase approximation

Sadiye Cakmak, Jameel-Un Nabi, Tahsin Babacan, Ismail Maras

摘要:

β衰变和铬同位素的电子俘获在恒星演化过程中起着关键作用。本文研究了铬的24种同位素($^{42-65}$ Cr)的电荷变化跃迁。这些包括富中子和缺中子的铬同位素。选取了三种不同的QRPA模型,即pn-QRPA、Pyatov方法(PM)和Schematic模型(SM),对铬同位素的Gamow-Teller(GT)跃迁进行了计算和研究。SM分别用于粒子-粒子($pp$)和$pp$ +粒子-空穴($ph$)通道。为了研究形变的影响,SM首先被用来假设核是球形的,然后被变形。PM用于$pp$和$pp$ + $ph$通道,但仅用于球形核的情况。通过考虑$pp$和$ph$力并考虑核的变形来进行pn-QRPA计算。最近的一项研究证明,这个版本的pn-QRPA是最好的计算GT强度分布之间的QRPA模型。与其他QRPA模型相比,pn-QRPA模型计算的GT分布具有较低的质心和较小的宽度。我们的计算结果也与其他理论模型和测量结果进行了比较。我们的结果是在体面的协议与以前的测量和壳模型计算。

英文摘要:

Beta decay and electron capture on isotopes of chromium are advocated to play a key role in the stellar evolution process. In this paper we endeavor to study charge-changing transitions for 24 isotopes of chromium ($^{42-65}$Cr). These include neutron-rich and neutron-deficient isotopes of chromium. Three different models from the QRPA genre, namely the pn-QRPA, the Pyatov method (PM) and the Schematic model (SM), were selected to calculate and study the Gamow-Teller (GT) transitions in chromium isotopes. The SM was employed separately in the particle-particle ($pp$) and $pp$ + particle-hole ($ph$) channels. To study the effect of deformation, the SM was first used assuming the nuclei to be spherical and later to be deformed. The PM was used both in $pp$ and $pp$ + $ph$ channels but only for the case of spherical nuclei. The pn-QRPA calculation was done by considering both $pp$ and $ph$ forces and taking deformation of nucleus into consideration. A recent study proved this version of pn-QRPA to be the best for calculation of GT strength distributions amongst the QRPA models. The pn-QRPA model calculated GT distributions had low-lying centroids and small widths as compared to other QRPA models. Our calculation results were also compared with other theoretical models and measurements wherever available. Our results are in decent agreement with previous measurements and shell model calculations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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