FöRFATTARE
Elfgren, Erik

DATUM
2000-12-18

INSTITUTION
Maskinteknik / Fysik

SAMMANFATTNING
This Master of Science thesis treats the hypercharge axion, which is a hypothetical pseudo-scalar particle with electroweak interactions.

First, the theoretical context and the motivations for this study are discussed. In short, the hypercharge axion is introduced to explain the dominance of matter over antimatter in the universe and the existence of large-scale magnetic fields.

Second, the phenomenological properties are analyzed and the distinguishing marks are underlined. These are basically the off-axis products of photons and Z^0s with an invariant mass equal to that of the axion. Third, the simulation is carried out with two photons producing the axion which decays into Z^0s and photons. The event simulation is run through the simulator ATLFAST of ATLAS (A Toroidal Large Hadron Collider ApparatuS) at CERN.

Finally, the characteristics of the axion decay are analyzed and the criteria for detection are presented. A study of the background is also included. The result is that for certain values of the axion mass and the mass scale (both in the order of a TeV), the hypercharge axion could be detected in ATLAS.

ISSN 1402-1617 / ISRN LTU-EX--00/334--SE / NR 2000:334