Génolini Yoann, Maurin David, Moskalenko Igor V, Unger Michael
Service de Physique Théorique, Université Libre de Bruxelles, Boulevard du Triomphe, CP225, 1050 Brussels, Belgium.
LPSC, Université Grenoble-Alpes, CNRS/IN2P3, 53 avenue des Martyrs, 38026 Grenoble, France.
Phys Rev C. 2018 Sep;98(3). doi: 10.1103/physrevc.98.034611. Epub 2018 Sep 21.
The precision of the current generation of cosmic-ray (CR) experiments, such as AMS-02, PAMELA, CALET, and ISS-CREAM, is now reaching ≈1-3% in a wide range in energy per nucleon from GeV/nucleon to multi-TeV/nucleon. Their correct interpretation could potentially lead to discoveries of new physics and subtle effects that were unthinkable just a decade ago. However, a major obstacle in doing so is the current uncertainty in the isotopic production cross sections that can be as high as 20-50% or even larger in some cases. While there is a recently reached consensus in the astrophysics community that new measurements of cross sections are desirable, no attempt to evaluate the importance of particular reaction channels and their required precision has been made yet. It is, however, clear that it is a huge work that requires an incremental approach. The goal of this study is to provide the ranking of the isotopic cross sections contributing to the production of the most astrophysically important CR Li, Be, B, C, and N species. In this paper, we (i) rank the reaction channels by their importance for a production of a particular isotope, (ii) provide comparisons plots between the models and data used, and (iii) evaluate a generic beam time necessary to reach a 3% precision in the production cross sections pertinent to the AMS-02 experiment. This first road map may become a starting point in the planning of new measurement campaigns that could be carried out in several nuclear and/or particle physics facilities around the world. A comprehensive evaluation of other isotopes ⩽ 30 will be a subject of follow-up studies.
当前一代宇宙射线（CR）实验，如阿尔法磁谱仪（AMS - 02）、帕梅拉实验（PAMELA）、CALET实验和国际空间站宇宙射线高能粒子分析仪（ISS - CREAM），在每个核子能量从GeV/核子到多TeV/核子的广泛范围内，精度现已达到约1% - 3%。对它们的正确解读可能会带来新物理和微妙效应的发现，而这些在仅仅十年前是不可想象的。然而，这样做的一个主要障碍是目前同位素产生截面的不确定性，在某些情况下，这种不确定性可能高达20% - 50%甚至更大。虽然天体物理学界最近已达成共识，认为需要对截面进行新的测量，但尚未有人尝试评估特定反应通道的重要性及其所需的精度。然而，很明显这是一项巨大的工作，需要采用渐进的方法。本研究的目标是对有助于产生天体物理学上最重要的CR锂、铍、硼、碳和氮物种的同位素截面进行排序。在本文中，我们（i）根据特定同位素产生的重要性对反应通道进行排序，（ii）给出所用模型与数据之间的对比图，以及（iii）评估在与AMS - 02实验相关的产生截面中达到3%精度所需的一般束流时间。这第一张路线图可能成为规划新测量活动的起点，这些新测量活动可在世界各地的几个核物理和/或粒子物理设施中开展。对其他质量数小于等于30的同位素进行全面评估将是后续研究的主题。
