Pseudo-Dirac dark matter leaves a trace.

Area of Science:

• Particle Physics
• Cosmology
• Dark Matter Physics

Background:

• Pseudo-Dirac dark matter arises from a Dirac fermion with a slight mass splitting due to a Majorana term.
• This mass splitting leads to a detectable decay length for the heavier to lighter state.
• Pseudo-Dirac dark matter exhibits distinct behaviors in relic abundance (Dirac-like) and direct detection (Majorana-like) experiments.

Purpose of the Study:

• To provide a general effective field theory treatment for pseudo-Dirac dark matter.
• To specialize this treatment for a pseudo-Dirac bino scenario.
• To establish methods for extracting dark matter properties from experimental observables.

Main Methods:

• Development of a general effective field theory framework.
• Application to a specific pseudo-Dirac bino model.
• Analysis of collider signatures, specifically displaced vertices and missing energy.
• Utilizing measurements of decay length and invariant mass of decay products.

Main Results:

• Pseudo-Dirac dark matter produces a distinct signature at colliders: a visible displaced vertex alongside missing energy.
• The mass and mass splitting of pseudo-Dirac dark matter can be determined from the decay length and invariant mass of its decay products.
• The effective field theory treatment provides a robust framework for analyzing this dark matter candidate.

Conclusions:

• Pseudo-Dirac dark matter is a viable dark matter candidate with unique experimental signatures.
• Collider experiments can detect and characterize pseudo-Dirac dark matter by observing displaced vertices and missing energy.
• Measurements of decay length and invariant mass are crucial for determining the fundamental properties of pseudo-Dirac dark matter.