Master Thesis Open Access
Sowa, Lars
{
"abstract": "<p>The SuperKEKB collider in Japan accelerates<br>\nelectrons and positrons which collide at an energy of 11 GeV aiming to produce B meson<br>\npairs. To analyse the properties of a B meson, it gets recombined from its decay daughters.<br>\nSince there are a lot of background events that mimic the signature of a B meson, it is<br>\nimportant to suppress these events. Such a suppression is called Continuum Suppression. This work aims to further improve the Deep Continuum Suppression, which is perfromed by a Multilayer Perceptron (MLP), by three points: Firstly, an MLP needs a fixed order for input particles. Therefore, this thesis<br>\npresents a reliable, self-attention-based input mechanism which allows for invariance under<br>\nthe particle order. Secondly, to guarantee certainty about the prediction of deep learning models, there is a<br>\nhigh interest in models with predictive uncertainties. This is addressed using the concept<br>\nof Deep Ensembles to predict uncertainties of continuum classifications.<br>\nFinally, the use of vertex information for the training of a model leads to a bias in<br>\ncertain analysis variables. Since this could lead to falsification of further studies, a Distance<br>\nCorrelation is used to decorrelate the Continuum Suppression model from third variables.</p>",
"author": [
{
"family": "Sowa, Lars"
}
],
"id": "22060",
"issued": {
"date-parts": [
[
2021,
7,
27
]
]
},
"language": "eng",
"title": "Deep Continuum Suppression with Predictive Uncertainties at the Belle II Experiment",
"type": "thesis"
}