Search for long-lived charged massive particles with the D0 detector

Area of Science:

• Particle Physics
• High Energy Physics
• Collider Physics

Background:

• The search for new massive particles is a key goal in high energy physics.
• Long-lived charged particles may arise in extensions to the Standard Model, such as supersymmetry.
• Previous searches have constrained the properties of such particles.

Purpose of the Study:

• To search for pair-produced long-lived charged massive particles.
• To set limits on the production cross section and mass of these hypothetical particles.
• To probe regions of parameter space not previously accessible.

Main Methods:

• Utilized 1.1 fb^{-1} of data from the D0 detector at the Fermilab Tevatron proton-antiproton collider.
• Employed time-of-flight measurements to identify and distinguish long-lived charged particles.
• Searched for tau sleptons, gaugino-like charginos, and Higgsino-like charginos.

Main Results:

• No significant excess of events consistent with the signal was observed.
• Set 95% confidence level (C.L.) upper limits on the cross section for stau pair production.
• Established lower mass limits for pair-produced charged gauginos (206 GeV) and Higgsinos (171 GeV).

Conclusions:

• The results place stringent constraints on the existence of long-lived charged sleptons and charginos within the studied mass ranges.
• The absence of a signal indicates that these specific supersymmetric particles are either heavier or produced less frequently than assumed.
• This search contributes to the ongoing effort to uncover physics beyond the Standard Model.