论文标题
Gamow Shell模型辐射捕获反应的描述$^8 $ b $（p，γ）$$^9 $ c
Gamow shell model description of the radiative capture reaction $^8$B$(p,γ)$$^9$C
论文作者
论文摘要
在低金属性超质量恒星中，热$ PP $链可以作为产生CNO核的替代方法。在高温的天体物理环境中，$^8 $ b的质子捕获可以比其β衰减更快，因此$^8 $ b $（p，γ）$$^9 $ c反应在热$ pp $链中起重要作用。由于$^8 $ b的不稳定性质和缺乏$^8 $ b光束，因此仅通过间接方法才能实现$^8 $ b $（p，γ）$$^9 $ c反应的测量，并且存在大型不确定性。耦合通道表示（GSM-CC）中的Gamow Shell模型用于研究质子辐射捕获反应$^8 $ b $（p，γ）$$^9 $ c。为了计算$^8 $ b $（p，γ）$$^9 $ c天体物理因子，所有E1，M1和E2从初始连续体状态到最终绑定状态$ {3/2} _1^ - $^$^9 $ C的过渡。还计算了$^{9} $ c的第一个共振状态$ {1/2} _1^ - $ C的共振捕获。 GSM-CC复制了$^9 $ C的实验性低能水平和质子排放阈值。计算出的天体物理因子与间接测量中存在的实验数据一致。根据天体物理兴趣的温度范围计算了直接捕获和共振捕获的反应速率。计算出的总天体物理$ S $因子以E1过渡到$^9 $ c的基础状态为主导。 GSM-CC计算表明，$ s $首先随着质量$ e _ {\ rm c.m。} $的能量的增加而增加，然后随着能量而减小。这与现有数据一致，现有数据的值较小，在零能量约为零的范围内，在0.2 mev $ \ leq e _ {\ rm c.m.} \ leq $ 0.6 mev的能量范围内。
In low metallicity supermassive stars, the hot $pp$ chain can serve as an alternative way to produce the CNO nuclei. In the astrophysical environment of high temperature, the proton capture of $^8$B can be faster than its beta decay, thus $^8$B$(p,γ)$$^9$C reaction plays an important role in the hot $pp$ chain. Due to the unstable nature of $^8$B and the lack of the $^8$B beam, the measurement of $^8$B$(p,γ)$$^9$C reaction can only be achieved by the indirect method, and large uncertainties exist. The Gamow shell model in the coupled-channel representation (GSM-CC) is applied to study the proton radiative capture reaction $^8$B$(p,γ)$$^9$C. For the calculation of the $^8$B$(p,γ)$$^9$C astrophysical factors, all E1, M1, and E2 transitions from the initial continuum states to the final bound states ${3/2}_1^-$of $^9$C are considered. The resonant capture to the first resonant state ${1/2}_1^-$ of $^{9}$C is also calculated. The experimental low-energy levels and the proton emission threshold in $^9$C are reproduced by the GSM-CC. The calculated astrophysical factors agrees with the existed experimental data from the indirect measurements. The reaction rates from the direct capture and resonant capture are calculated for the temperature range of astrophysical interest. The calculated total astrophysical $S$ factor is dominated by the E1 transition to the ground state of $^9$C. The GSM-CC calculations suggest that $S$ first increase with the energy of the center of mass $E_{\rm c.m.}$, and then decrease with the energy. This agrees with the existing data, which has smaller values at around zero energy and larger value in the energy range of 0.2 MeV $\leq E_{\rm c.m.} \leq$ 0.6 MeV.
