Direct Measurement of Astrophysically Important Resonances in $^{38}\mathrm{K}(p, γ){}^{39}\mathrm{Ca}$
G. Christian, G. Lotay, C. Ruiz, C. Akers, D. S. Burke, W. N. Catford, A. A. Chen, D. Connolly, B. Davids, J. Fallis, U. Hager, D. Hutcheon, A. Mahl, A. Rojas, X. Sun
备注：
11 pages, 6 figures, accepted for publication in Phys. Rev. C
According to sensitivity studies, the $^{38}\mathrm{K}\left( p, γ\right){}^{39}\mathrm{Ca}$ reaction has a significant influence on $\mathrm{Ar}$, $\mathrm{K}$, and $\mathrm{Ca}$ production in classical novae. In order to constrain the rate of this reaction, we have performed a direct measurement of the strengths of three candidate $\ell = 0$ resonances within the Gamow window, at $386 \pm 10~\mathrm{keV}$, $515 \pm 10~\mathrm{keV}$, and $689 \pm 10~\mathrm{keV}$. The experiment was performed in inverse kinematics using a beam of unstable $^{38}\mathrm{K}$ impinged on a windowless $\mathrm{H}_2$ target. The $^{39}\mathrm{Ca}$ recoils and prompt $γ$ rays from $^{38}\mathrm{K}\left( p, γ\right){}^{39}\mathrm{Ca}$ reactions were detected in coincidence using a recoil mass separator and a BGO array, respectively. For the $689$ keV resonance, we observed a clear recoil-$γ$ coincidence signal and extracted resonance strength and energy values of $120^{+50}_{-30}~\mathrm{(stat.)}^{+20}_{-60}~\mathrm{(sys.)}~\mathrm{meV}$ and $679^{+2}_{-1}~\mathrm{(stat.)} \pm 1~\mathrm{(sys.)}~\mathrm{keV}$, respectively. We also performed a singles analysis, extracting a resonance strength of $120 \pm 20~\mathrm{(stat.)} \pm 15~\mathrm{(sys.)}~\mathrm{meV}$, consistent with the coincidence result. For the $386$ keV and $515$ keV resonances, we extract $90\%$ confidence level upper limits of $2.54$ meV and $18.4$ meV, respectively. We have established a new recommended $^{38}\mathrm{K}(p, γ){}^{39}\mathrm{Ca}$ rate based on experimental information, which reduces overall uncertainties near the peak temperatures of nova burning by a factor of ${\sim} 250$. Using the rate obtained in this work in model calculations of the hottest oxygen-neon novae reduces overall uncertainties on $\mathrm{Ar}$, $\mathrm{K}$, and $\mathrm{Ca}$ synthesis to factors of $15$ or less in all cases.
Study of the astrophysically important $\boldsymbol{^{23}\mathrm{Na}(α,p)^{26}\mathrm{Mg}}$ and $\boldsymbol{^{23}\mathrm{Na}(α,n)^{26}\mathrm{Al}}$ reactions
$^{23}$ Na $(α,p)^{26}$ Mg和$^{23}$ Na $(α,n)^{26}$ Al反应对于我们理解大质量恒星中的$^{26}$ Al丰度具有重要意义。这项工作的目的是报告使用主动靶系统直接和同时测量这些天体物理学上重要的反应。以$^{4}$ He为活性靶气体，采用逆运动学方法研究了反应。我们测量的激发函数的能量范围约为2至6 MeV的质心。我们发现$^{23}$ Na $(α,p)^{26}$ Mg反应和$^{23}$ Na $(α,n)^{26}$ Al反应的截面与以前的实验和统计模型计算符合得很好。
New measurement of the $E_{\mathrm{c.m.}}=323$ keV resonance in the $^{19}$F$($p,γ$)$^{20}$Ne reaction
在低于0.1 GK的温度下，$^{19}$ F $(p,γ)^{20}$ Ne反应是CNO循环的唯一突破路径。由于来自强得多的$^{19}$ F $(p,α)^{16}$ O反应通道的丰富的$γ$射线背景，从技术角度来看，该反应的实验研究是具有挑战性的。在这里，我们提出了第一个逆运动学研究的$^{19}$ F $(p,γ)^{20}$ Ne反应，在其中，我们测量的323 keV共振的强度。我们发现一个强度值为$ωγ= 3.3^{+1.1}_{-0.9}$毫电子伏，这是一个比最近的研究大两个因素。这种差异很可能是由于直接到基态的过渡，以前的研究并不敏感。我们还观察到过渡到第一个$2^{-}$状态，这在以前的研究中没有观察到这种共振。计算了一个新的热核反应速率，并与文献进行了比较。
Multi-probe study of excited states in $\mathrm{^{12}C}$: disentangling the sources of monopole strength between the Hoyle state and $E_{x} = 13$ MeV
iThemba LABS, National Research Foundation（iThemba实验室，国家研究基金会）；Department of Physics, University of Stellenbosch（斯泰伦博斯大学物理系）；Department of Physics, University of Oslo（奥斯陆大学物理系）；School of Physics, University of the Witwatersrand（威特沃特斯兰德大学物理学院）；NRC Kurchatov Institute（库尔恰托夫研究所）；Flerov Laboratory of Nuclear Reactions, JINR（杜布纳联合核研究所弗廖罗夫核反应实验室）；School of Physics and Astronomy, University of Birmingham（伯明翰大学物理与天文学院）；Nuclear Energy Group, ESRIG, University of Groningen（格罗宁根大学ESRIG核能组）；Department of Physics and Astronomy, University of the Western Cape（西开普大学物理与天文系）
Observation of the centrality-dependent difference in directed flow between charged kaons and $K^{*0}$ resonances in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 14.6, 19.6 and 27 GeV
Measurement of $\mathrm{^{75}As}(\mathrm{n},γ)\mathrm{^{76}As}$ reaction relevant to 0$νββ$ decay searches of $\mathrm{^{76}Ge}$ and astrophysical $s$-process temperatures
Institute of Modern Physics, Chinese Academy of Sciences（中国科学院近代物理研究所）；Guangxi Key Laboratory of Nuclear Physics and Technology, College of Physics and Technology, Guangxi Normal University（广西师范大学物理科学与技术学院）；Advanced Energy Science and Technology, Guangdong Laboratory（广东省实验室先进能源科学与技术）；Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Institute of Modern Physics, Department of Nuclear Science and Technology, Fudan University（复旦大学核科学技术学院）；Shanghai Research Center for Theoretical Nuclear Physics, NSFC and Fudan University（上海 theoretical 核物理研究中心）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；Spallation Neutron Source Science Center（散裂中子源科学中心）
Sub-threshold $ϕ$ and $Ξ^-$ production by high mass resonances with UrQMD
我们提出了一个可能的解释深亚阈值，$ϕ$和$Ξ^-$生产与HADES实验测量在Ar+KCl反应在$E_{\mathrm{lab}}=1.76$ A GeV的产量和目前的预测金+金反应在$E_{\mathrm{lab}}=1.23$ A GeV。为了解释$ϕ$和$Ξ^-$强子令人惊讶的高产率，我们提出了新的衰变通道的高质量重子共振。这些新的衰变通道受到基本$\mathrm{p+p}\rightarrow \mathrm{p+p+}ϕ$横截面和p+Nb中$Ξ^-$产生的限制。基于对基元反应的拟合，得到了深亚阈Ar+KCl反应中$ϕ$和$Ξ^-$产生的满意描述，以及在冷核物质中质子诱导$ϕ$产生的核透明比。结果表明，低能核碰撞中罕见的奇异粒子产生数据不需要新的介质效应来描述。
Effects of resonance weak decays and hadronic re-scattering on the proton number fluctuations in Au + Au collisions at $\sqrt{s_\mathrm{NN}} = 5$ GeV from JAM model
Hadronic resonance production with the ALICE experiment in pp and Pb-Pb collisions at LHC energies
用ALICE实验测量了$\sqrt{s}=7$ TeV pp碰撞和$\sqrt{s_{_\mathrm{NN}}}=2.76$ TeV Pb-Pb碰撞中的强子共振$\mathrm{K}^{*}(892)^{0}$、$ϕ$（1020）和$Σ(1385)^{\pm}$。讨论了横动量谱、粒子比、核修正因子以及与模型预测的比较。此外，ALICE的结果进行了比较，在RHIC能源获得的数据。
Improved $S$-factor of the $^{13}$C(p,$γ$)$^{14}$N reaction at $E_{\mathrm{p}}\,=\,$330-740 keV and parameters of resonances at 448 keV and 551 keV
University of Edinburgh（爱丁堡大学）；HUN-REN, Institute for Nuclear Research (HUN-REN Atomki)（匈牙利研究与创新网络核子研究所（HUN-REN Atomki））；University of Surrey（萨里大学）；University of Debrecen（德布勒森大学）
Astrophysical $S_{E2}$ factor of the ${}^{12}\mathrm{C}(α,γ){}^{16}\mathrm{O}$ reaction through the ${}^{12}\mathrm{C}({}^{11}\mathrm{B},{}^{7}\mathrm{Li}){}^{16}\mathrm{O}$ transfer reaction
