Alternative coalescence model for deuteron, tritium, helium-3 and their antinuclei
Alternative coalescence model for deuteron, tritium, helium-3 and their antinuclei
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DOI：
10.1140/epja/s10050-019-00007-9
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发表时间：
2019-05
期刊：
影响因子：
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通讯作者：
M. Kachelrieß;S. Ostapchenko;J. Tjemsland
中科院分区：
文献类型：
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作者：
M. Kachelrieß;S. Ostapchenko;J. Tjemsland
由于低的天体物理背景，反氘和反氦核被认为是银河系暗物质湮灭和衰变的探测通道。为了估计各种暗物质模型的信号和天体物理背景，人们通常采用蒙特卡罗框架中的合并模型。这使得人们可以在逐个事件的基础上处理反核的产生，从而考虑到参与该过程的反核子之间的动量相关性。然而，这种方法缺乏一个潜在的微观图片，并从不同的反应拟合得到的聚结参数的数值变化很大。在这里，我们建议，而不是结合联合收割机事件的Monte Carlo模拟与微观聚结图片的基础上的维格纳函数表示所产生的反核子状态。这种方法使我们能够在半经典图像中包括依赖于过程的形成区域的大小和动量相关性。该模型包含一个单一的，通用的参数，这是固定的，通过拟合生产光谱的质子-质子相互作用，测量在大型强子对撞机。利用这个值，模型很好地描述了电子-正电子湮灭和质子-质子碰撞中各种反核的产生。
Antideuteron and antihelium nuclei have been proposed as a detection channel for dark matter annihilations and decays in the Milky Way, due to the low astrophysical background expected. To estimate both the signal for various dark matter models and the astrophysical background, one usually employs the coalescence model in a Monte Carlo framework. This allows one to treat the production of antinuclei on an event-by-event basis, thereby taking into account momentum correlations between the antinucleons involved in the process. This approach lacks, however, an underlying microscopic picture, and the numerical value of the coalescence parameter obtained from fits to different reactions varies considerably. Here we propose instead to combine event-by-event Monte Carlo simulations with a microscopic coalescence picture based on the Wigner function representations of the produced antinuclei states. This approach allows us to include in a semi-classical picture both the size of the formation region, which is process dependent, and the momentum correlations. The model contains a single, universal parameter which is fixed by fitting the production spectra of antideuterons in proton–proton interactions, measured at the Large Hadron Collider. Using this value, the model describes well the production of various antinuclei both in electron–positron annihilation and in proton–proton collisions.