Analysis of zero Pion CC neutrino interactions in ANNIE

该项目的目的是分析ANNIE实验的数据，在考虑中子多重性的情况下，分析中微子与带电电流相互作用的截面，而不考虑出射的π介子。ANNIE是费米实验室短基线中微子束中掺钆的水切伦科夫探测器。ANNIE的主要任务是测量来自该束的中微子相互作用，利用探测器中的钆可以很好地确定每个事件产生的中子数。这样得到的截面对长基线中微子实验中的能量测定以及扩散超新星中微子背景和质子衰变实验中的本底估计都有很大的影响。 此外，它们将有助于理解核内的哪些过程会影响出射π介子的数量，以及单个过程（如π介子吸收和所谓的2粒子2空穴过程）的强度。为此，必须将测量的速率与通过使用不同发电机的模拟获得的预测进行比较。然而，对于大多数常见的中微子发生器来说，这取决于软件中的一些微调，这在不同的实验中是不同的。GIBUU是一个基于输运理论的生成器，因此它也将被集成到ANNIE的模拟软件中。这位博士后应该在这些分析中发挥主导作用，并开发完整的分析链，从数据选择开始，通过模拟预测，到截面计算。与此密切相关的是使用已经提到的生成器GiBUU为ANNIE，其预测将被用作比较。根据完成这些任务的速度，可能会进行进一步的调查。这意味着，将调查在某些情况下产生的潜力。第一种情况是用反中微子而不是中微子照射安妮。对于第二种情况，假设使用水基液体闪烁体代替水作为检测器介质。在第三种情况下，我们将研究在多大程度上值得使用中微子束的时间结构，将其分解为具有不同成分和能谱的部分进行分析。

The aim of the project is the analysis of the data of the ANNIE experiment with regard to the cross sections of neutrino interactions with charged currents without outgoing pions under consideration of neutron multiplicity. ANNIE is a water Cherenkov detector dopted with gadolinium in the Short Baseline Neutrino Beam at Fermilab. ANNIE's main task is to measure neutrino interactions from this beam, taking advantage of the fact that the gadolinium in the detector allows the number of neutrons produced per event to be determined very well. The cross sections obtained in this way will have a great influence on the energy determination in long-baseline neutrino experiments as well as on the background estimation in diffuse supernova neutrino background and proton decay experiments. Furthermore, they will help to understand which processes within the nuclei influence the number of outgoing pions, and how strongly individual processes, such as pion absorption and so-called 2-particle-2-hole processes, are involved. For this purpose, the measured rates have to be compared with predictions obtained by simulation using different generators. However, for most common neutrino generators this depends on some fine tuning in the software, which differs from experiment to experiment. This is not the case with GIBUU, a generator based on transport theory, which is why it is also to be integrated into ANNIE's simulation software.The proposed postdoc should take a leading role in these analyses and develop the complete analysis chain, starting with data selection, through prediction by simulation, to the calculation of the cross sections. Closely related to this is the use of the already mentioned generator GiBUU for ANNIE, whose predictions are to be used as a comparison. Depending on the speed with which these tasks can be completed, further investigations may follow. That means, that the potential that arises under certain scenarios will be investigated. The first scenario is the irradiation of ANNIE's with anti-neutrinos instead of neutrinos. For the second scenario, it is assumed that water-based liquid scintillator is used as the detector medium instead of water. And in the third scenario we will investigate to what extent it is worthwhile to use the temporal structure of the neutrino beam to break it down into parts with different compositions and energy spectra for analysis.