Quantum three-body calculation of the nonresonant triple-\alpha reaction rate at low temperatures

The triple-\alpha reaction rate is re-evaluated by directly solving the three-body Schr\"odinger equation. The resonant and nonresonant processes are treated on the same footing using the continuum-discretized coupled-channels method for three-body scattering. Accurate description of the \alpha-\alpha nonresonant states significantly quenches the Coulomb barrier between the two-\alpha's and the third \alpha particle. Consequently, the \alpha-\alpha nonresonant continuum states below the resonance at 92.04 keV, i.e., the ground state of 8Be, give markedly larger contribution at low temperatures than in foregoing studies. We show that Nomoto's method for three-body nonresonant capture processes, which is adopted in the NACRE compilation and many other studies, is a crude approximation of the accurate quantum three-body model calculation. We find about 20 orders-of-magnitude enhancement of the triple-\alpha reaction rate around 10^7 K compared to the rate of NACRE.Comment: To be published in Prog. Theor. Phys. Vol.121, No.4. More detailed description of numerical inputs, further discussion in relation to Nomoto's method (NACRE), new typeset using PTP Te

The Outline of the High School Trial Corresponding to the University Entrance Selection Reform : Special Examination Subcommittee of the National Six University Collaborative Consortium Education Collaboration Organization

6 大学連携事業として，評価したい資質について掘り下げ質問を行う構造化面接と，面接に代わる筆記試験であるペーパーインタビューについて，県内の高等学校の協力を得て2019 年度にトライアルを行った。評価した資質は「新たなこと追究しようとする態度」と「協働して取り組む態度」であり，まず，構造化面接とペーパーインタビューの結果を本学の教員が評価し，その結果を高校教員が個々の受験生に抱いている日常的評価と比較した。トライアルの結果，構造化面接の有効性ならびに，受験者全員に面接を課すことが，時間的，人員的に実施困難な入試におけるペーパーインタビューの有効性が確認された。同時に，測ろうとする資質によっては，面接との評価結果が異なる部分があることも明らかとなった

Eikonal Reaction Theory for Neutron-Removal Reaction

We present an accurate method of treating the one-neutron removal reaction at intermediate incident energies induced by both nuclear and Coulomb interactions. In the method, the nuclear and Coulomb breakup processes are consistently treated by the method of continuum discretized coupled channels without making the adiabatic approximation to the Coulomb interaction, so that the removal cross section calculated never diverges. This method is applied to recently measured one-neutron removal cross section for $^{31}$Ne+$^{12}$C scattering at 230 MeV/nucleon and $^{31}$Ne+$^{208}$Pb scattering at 234 MeV/nucleon. The spectroscopic factor and the asymptotic normalization coefficient of the last neutron in $^{31}$Ne are evaluated.Comment: 10 pages, 1 figur