Light bottom squark and gluino confront electroweak precision measurements

Area of Science:

• Particle Physics
• High Energy Physics
• Supersymmetry

Background:

• The Tevatron observed an excess in b quark production cross section.
• Light sbottom and gluino particles were proposed to explain this excess.
• Electroweak precision measurements provide stringent constraints on particle physics models.

Purpose of the Study:

• To assess the compatibility of light sbottom and gluino particles with electroweak precision measurements.
• To investigate the impact of supersymmetric-QCD corrections on electroweak observables.
• To evaluate the viability of a specific supersymmetric scenario.

Main Methods:

• Calculated supersymmetric-QCD (SUSY-QCD) corrections to the Zbb vertex.
• Included gauge boson propagator corrections from light stops.
• Compared theoretical predictions with experimental electroweak precision data.

Main Results:

• The presence of light sbottom and gluino particles leads to significant SUSY-QCD corrections.
• Electroweak precision measurements are sensitive to these corrections.
• The scenario with light sbottom and gluino is strongly disfavored.

Conclusions:

• The proposed scenario explaining b quark excess at the Tevatron is inconsistent with current electroweak precision data.
• Light sbottom and gluino particles, as hypothesized, are unlikely.
• Further theoretical and experimental investigations are needed for b quark production anomalies.