Search for Dark Matter Candidates and Large Extra Dimensions in Events with a Photon and Missing Transverse Momentum in $pp$ Collision Data at $\sqrt{s}\mathbf{=}7\mathrm{TeV}$ with the ATLAS Detector

Results of a search for new phenomena in events with an energetic photon and large missing transverse momentum in proton-proton collisions at $\sqrt{s}=7\mathrm{TeV}$ are reported. Data collected by the ATLAS experiment at the LHC corresponding to an integrated luminosity of $4.6{\mathrm{fb}}^{-1}$ are used. Good agreement is observed between the data and the standard model predictions. The results are translated into exclusion limits on models with large extra spatial dimensions and on pair production of weakly interacting dark matter candidates.

Figure 1

The measured $E_T^{\mathrm{miss}}$ distribution (black dots) compared to the SM (solid lines), $\mathrm{SM}+\mathrm{ADD}$ (dashed lines), and $\mathrm{SM}+\mathrm{WIMP}$ (dotted lines) predictions, for two particular ADD and WIMP scenarios.

Figure 2

Observed (solid lines) and expected (dash-dotted lines) 95% C.L. limits on $M_D$ as a function of the number of extra spatial dimensions $n$ in the ADD model. The results are compared with previous results [1, 3, 6] (other lines). In [6], weights are applied that suppress the region with $\widehat{s}>M_D^2$.

Figure 3

90% C.L. upper limits on the nucleon-WIMP cross section as a function of $m$ for spin-dependent (left) and spin-independent (right) interactions [12, 39]. The results are compared with previous monojet and monophoton results at colliders [4, 6, 8] and results from direct detection experiments [11].