Constraints on Dark Matter from Colliders

TL;DR

The paper investigates constraints on light dark matter that interacts with Standard Model particles via higher-dimensional operators in an effective field theory. It analyzes Tevatron monojet data and prospective LHC searches to bound the operator scale $M_*$ and to relate these bounds to direct-detection cross sections. The findings show that collider bounds can dominate direct-detection limits, especially for spin-dependent interactions and gluon-coupled operators, with particular strength at low $m_{chi}$. It also highlights the importance of UV completions and the potential EFT breakdown if a direct-detection signal implies a light mediator. Overall, the work provides a model-independent collider probe that complements direct detection across a broad WIMP parameter space.

Abstract

We show that colliders can impose strong constraints on models of dark matter, in particular when the dark matter is light. We analyze models where the dark matter is a fermion or scalar interacting with quarks and/or gluons through an effective theory containing higher dimensional operators which represent heavier states that have been integrated out of the effective field theory. We determine bounds from existing Tevatron searches for monojets as well as expected LHC reaches for a discovery. We find that colliders can provide information which is complementary or in some cases even superior to experiments searching for direct detection of dark matter through its scattering with nuclei. In particular, both the Tevatron and the LHC can outperform spin dependent searches by an order of magnitude or better over much of parameter space, and if the dark matter couples mainly to gluons, the LHC can place bounds superior to any spin independent search.

Figures (16)

• Figure 1: Current experimental limits on spin-independent WIMP direct detection from CRESST Angloher:2002in, CDMS Ahmed:2009zw, Xenon 10 Angle:2007uj, CoGeNT Aalseth:2010vx, and Xenon 100 Aprile:2010um, (solid lines as labeled), as well as the CoGeNT favored region Aalseth:2010vx and future reach estimates for SCDMS Akerib:2006rr and Xenon 100 Aprile:2009yh, where we have chosen the line using a threshold of 3PE and the conservative extrapolation of $\mathcal{L}_{eff}$ (dashed lines as labeled). Also shown are the current Tevatron exclusion for the operator D11 (solid magenta line) as well as LHC discovery reaches (dashed lines as labeled) for relevant operators.
• Figure 2: Current experimental limits on spin-dependent WIMP direct detection from Picasso Archambault:2009sm, KIMS Lee.:2007qn, and Xenon 10 Angle:2007uj, as well as the future reach of DMTPC Sciolla:2009fb. Also shown are the current Tevatron exclusions (solid lines as labeled) and LHC discovery reaches (dashed lines as labeled) for relevant operators.
• Figure 3: Same as Fig. \ref{['fig:DSIplot']}, but with Tevatron exclusions and LHC reaches for complex scalar WIMP operators, as labeled.
• Figure 4: Same as Fig. \ref{['fig:DSIplot']}, but with Tevatron exclusions and LHC reaches for real scalar WIMP operators, as labeled.
• Figure 5: A cartoon representation of previous limits due to direct detection experiments as well as constraints from Earth heating and cosmic rays Mack:2007xj, with new exclusions from Tevatron searches for Dirac WIMPs superimposed.