Hadronic Structure Measurements of the Photon by DELPHI at LEP II

Research output: ThesisDoctoral Thesis (compilation)


This thesis is mainly an analysis of data taken by the VSAT detector in the DELPHI experiment at the LEP II collider at CERN. The analysis spans from 1998 to 2000, with a center of mass energy ranging from 189 to 206 GeV. The VSAT calorimeter was constructed to be a luminosity and background monitor for the DELPHI experiment, and a full description of the luminosity and background analysis for the LEP II conditions is presented.

The VSAT detector is located in the very forward direction and covers angles between three and eight milliradians since 1998. This also makes the detector to an excellent tool for studying two photon physics, as the outgoing electrons from a two-photon collision mainly are located at small angles. A full study of the VSAT double tag data between 1998 and 2000 is presented. Gamma-gamma collisions with an invariant mass reaching up to 100 GeV could be explored in a Q2 range of 0.2-0.8 GeV. With help of data from the STIC detector,which is located at larger polar angles, two photon collisions could also be probed with a Q2 between 20 and 100 GeV.


  • Andreas Nygren
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Subatomic Physics


  • Elementarpartikelfysik, DELPHI, LEP, VSAT, luminosity, two-photon physics, cross section, double tag, bhabha, background, structure function, kvantfältteori, quantum field theory, Elementary particle physics, Fysicumarkivet A:2001:Nygren
Original languageEnglish
Awarding Institution
Supervisors/Assistant supervisor
  • [unknown], [unknown], Supervisor, External person
Award date2001 Sep 28
Print ISBNs91-628-4932-8
Publication statusPublished - 2001
Publication categoryResearch

Bibliographic note

Defence details Date: 2001-09-28 Time: 10:15 Place: Lecture hall B at Fysicum External reviewer(s) Name: Soldner-Rembold, Stefan Title: Prog. Affiliation: Geneve --- Article: A:DELPHI Note 2001-005 CAL 145B:DELPHI Note 2001-002 Talk 021C:DELPHI Note 2000-173 Phys 884D:DELPHI Note 99-157 LEDI 87E:DELPHI Note 2000-054 Phys 857F:DELPHI NOte 99-163 CAL 143G:DELPHI Note 99-175 Phys 814H:DELPHI Note 99-49 LEDI 11