Search for Dark Matter and Large Extra Dimensions in pp Collisions Yielding a Photon and Missing Transverse Energy at CMS

TL;DR

This paper reports a search for dark matter particles and large extra dimensions in proton-proton collisions producing a photon and missing energy, setting new limits on these phenomena based on CMS data at 7 TeV.

Contribution

The study provides the most sensitive upper limits to date on dark matter production and large extra dimensions using photon plus missing energy events at the LHC.

Findings

No excess observed over standard model predictions.

Set 90% CL upper limits on dark matter production cross sections.

Excluded Planck scales between 1.64 and 1.73 TeV for extra dimensions.

Abstract

Results are presented from a search for new physics in the final state containing a photon and missing transverse energy. The data corresponds to an integrated luminosity of 5.0 fb$^{-1}$ collected in pp collisions at $\sqrt{s}$= 7 TeV by the CMS experiment. The observed event yield agrees with standard model expectations. Using models for the production of dark matter particles($\chi$), we set 90$% confidence level (C.L.) upper limits of 13.6-15.4 fb on $\chi$ production in the $\gamma$+ $\met$ state. These provide the most sensitive upper limits for spin-dependent $\chi$-nucleon scattering for \c{hi} masses between 1 and 100 GeV. For spin dependent contributions, the present limits are extended to M($\chi$) $<$ 3.5 GeV. For ADD models with 3-6 large extra dimensions, our data exclude extra-dimensional Planck scales between 1.64 and 1.73 TeV at 95% C.L.