Constraining Dark Matter Interactions with Pseudoscalar and Scalar Mediators Using Collider Searches for Multijets...

Area of Science:

• Particle Physics
• Cosmology
• Astrophysics

Background:

• Collider dark matter searches primarily utilize the monojet signature, detecting missing transverse energy plus one or two jets.
• Pseudoscalar and scalar mediator models are key theoretical frameworks for dark matter interactions.
• An excess in GeV gamma rays observed by the Fermi Large Area Telescope suggests potential dark matter signals.

Purpose of the Study:

• To compare the sensitivity of multijet versus monojet searches for dark matter detection.
• To investigate the constraints imposed by multijet searches on pseudoscalar interpretations of the Fermi gamma-ray excess.
• To assess the future reach of multijet searches at the Large Hadron Collider.

Main Methods:

• Analysis of simulated collider events featuring missing transverse energy and varying numbers of jets.
• Application of a simplified model with pseudoscalar interactions to explain astrophysical observations.
• Evaluation of parameter space constraints based on mediator and dark matter masses.

Main Results:

• Multijet searches demonstrate significantly higher sensitivity than monojet searches for pseudoscalar- and scalar-mediated dark matter interactions.
• Current multijet searches already place strong constraints on pseudoscalar interpretations of the Fermi gamma-ray excess, particularly when the mediator mass exceeds twice the dark matter mass (M_{A} > 2m_{DM}).
• The upcoming Large Hadron Collider run will fully explore the remaining parameter space for M_{A} > 2m_{DM}.

Conclusions:

• Multijet final states are crucial for maximizing dark matter detection sensitivity at colliders.
• Complementing monojet searches with multijet analyses provides a more comprehensive strategy for dark matter discovery.
• Collider data, particularly from multijet events, offers powerful constraints on dark matter models, including those explaining astrophysical anomalies.