January 12, 2021 Master Thesis Open Access

Pfeffer, Emanuel

JSON Export

{
  "conceptrecid": "22071", 
  "created": "2021-11-10T15:47:35.717635+00:00", 
  "files": [
    {
      "bucket": "de37d1da-9628-46d5-b580-9827bcc308bd", 
      "checksum": "md5:519f7c9df7dc8f930eda005fd3f1a86a", 
      "key": "Masterthesis_Emanuel_Pfeffer.pdf", 
      "links": {
        "self": "https://publish.etp.kit.edu/api/files/de37d1da-9628-46d5-b580-9827bcc308bd/Masterthesis_Emanuel_Pfeffer.pdf"
      }, 
      "size": 5280328, 
      "type": "pdf"
    }
  ], 
  "id": 22082, 
  "links": {
    "bucket": "https://publish.etp.kit.edu/api/files/de37d1da-9628-46d5-b580-9827bcc308bd", 
    "html": "https://publish.etp.kit.edu/record/22082", 
    "latest": "https://publish.etp.kit.edu/api/records/22082", 
    "latest_html": "https://publish.etp.kit.edu/record/22082"
  }, 
  "metadata": {
    "access_right": "open", 
    "access_right_category": "success", 
    "communities": [
      {
        "id": "cms"
      }, 
      {
        "id": "etp"
      }
    ], 
    "contributors": [], 
    "creators": [
      {
        "affiliation": "KIT/ETP", 
        "name": "Pfeffer, Emanuel"
      }
    ], 
    "description": "<p>In this thesis, the interplay of two elementary particles of the SM, the two heaviest quarks top (t) and bottom (b), is studied in detail. Processes in which a top quark-antiquark pair occurs in associated production with two bottom quarks (tt+bb)&nbsp;play an important role in particle physics. The two quarks show a high mass difference and their associated production is therefore particularly difficult to model, accompanied by large uncertainties [6]. In addition, events involving this process constitute a large irreducible background in measurements of tt+H production in H&nbsp;&rarr;&nbsp;bb&nbsp;decays. These measurements are an essential test of the SM and an important constraint of physics beyond the SM. Consequently, the tt+bb&nbsp;process needs to be thoroughly understood.</p>\n\n<p>Events comprising tt+bb&nbsp;processes are analyzed at two different Monte Carlo event simulation levels in this thesis.<br>\nThe first part compares different existing event simulations used at the CMS experiment for the tt+bb&nbsp;process in the single-lepton channel and investigates possible differences in the modeling. The analysis is technically realized in a way that allows a direct comparison of the simulations with those of the ATLAS experiment. The comparison of simulations of both experiments is performed building on this analysis. This enables the design of a common strategy between ATLAS and CMS.</p>\n\n<p>The second part focuses on strategies for assigning b jets to their origin. Since top quarks decay into b quarks almost exclusively, the final state of an event involving the tt+bb&nbsp;process usually consists of four or more b jets. However, it is unknown in the event reconstruction which b jets result from top quark decays and which originate from additional gluon radiation and subsequent splittings into pairs of b quarks in the event.</p>", 
    "keywords": [
      "CERN", 
      "CMS", 
      "Experiment", 
      "Monte Carlo Simulation", 
      "Machine Learning", 
      "Artificial Intelligence", 
      "Deep Neural Networks", 
      "tt+bb", 
      "top"
    ], 
    "language": "eng", 
    "publication_date": "2021-01-12", 
    "relations": {
      "version": [
        {
          "count": 1, 
          "index": 0, 
          "is_last": true, 
          "last_child": {
            "pid_type": "recid", 
            "pid_value": "22082"
          }, 
          "parent": {
            "pid_type": "recid", 
            "pid_value": "22071"
          }
        }
      ]
    }, 
    "resource_type": {
      "subtype": "master-thesis", 
      "title": "Master Thesis", 
      "type": "thesis"
    }, 
    "thesis": {
      "report_number": "ETP-KA/2021-01", 
      "supervisors": [
        {
          "affiliation": "KIT/ETP", 
          "name": "Husemann, Ulrich"
        }, 
        {
          "affiliation": "KIT/ETP", 
          "name": "M\u00fcller, Thomas"
        }, 
        {
          "affiliation": "KIT/ETP", 
          "name": "Schr\u00f6der, Matthias"
        }, 
        {
          "affiliation": "KIT/ETP", 
          "name": "van der Linden, Jan"
        }
      ]
    }, 
    "title": "Studies on tt+bb production at the CMS experiment"
  }, 
  "owners": [
    79
  ], 
  "revision": 2, 
  "stats": {}, 
  "updated": "2022-12-02T16:18:56.125787+00:00"
}