Search for dark matter, extra dimensions, and unparticles in monojet events in proton–proton collisions at $$\sqrt{s} = 8$$ s = 8 $$\,{\mathrm{TeV}}\,$$ TeV

Abstract

Results are presented from a search for particle dark matter (DM), extra dimensions, and unparticles using events containing a jet and an imbalance in transverse momentum. The data were collected by the CMS detector in proton–proton collisions at the LHC and correspond to an integrated luminosity of 19.7at a centre-of-mass energy of 8. The number of observed events is found to be consistent with the standard model prediction. Limits are placed on the DM-nucleon scattering cross section as a function of the DM particle mass for spin-dependent and spin-independent interactions. Limits are also placed on the scale parameter in the Arkani-Hamed, Dimopoulos, and Dvali (ADD) model of large extra dimensions, and on the unparticle model parameter . The constraints on ADD models and unparticles are the most stringent limits in this channel and those on the DM-nucleon scattering cross section are an improvement over previous collider results.

Spherical cows in dark matter indirect detection

“…Gravitational evidence for dark matter (DM) is well established [1][2][3], yet DM still evades all other means of detection [4][5][6][7][8]. A current focus of the search for DM is indirect detection: DM annihilation or decay could produce observable Standard Model (SM) particles, including photons.…”

Collider signatures of hylogenesis

“…We have found that the most stringent bounds on parameters of the model in question are obtained for the cut E miss T > 500 GeV. Note that E miss T in [21] is defined as the magnitude of vector sum of transverse momentum of all particles in the event. For our calculations this means that E miss T coincides with transverse momentum of jet, p j T .…”

“…Here we discuss bounds on the model parameters from results of LHC searches for monojet and missing energy signature [19][20][21]. Sensitivity of the collider (Tevatron and LHC) searches to hylogenesis model has been discussed in [13].…”

“…To obtain exclusion plots for model parameters we use the latest results of CMS searches for jet+E miss T [21]. These searches at √ s = 8 TeV with 19.7 fb −1 integrated luminosity adopted cut on jet rapidity |η jet | < 2.4 and a cut on transverse missing energy 1 .…”

“…These searches at √ s = 8 TeV with 19.7 fb −1 integrated luminosity adopted cut on jet rapidity |η jet | < 2.4 and a cut on transverse missing energy 1 . The results of 1 Moreover, the event selection procedure of [21] allows a second jet which is separated from the first by less that 2.5 azimuth radian, ∆φ(j 1 , j 2 ) < 2.5. Such angular requirement suppresses dijet QCD events.…”