Probing Dark Matter at the LHC Using Vector Boson Fusion Processes

Vector boson fusion processes at the Large Hadron Collider (LHC) provide a unique opportunity to search for new physics with electroweak couplings. A feasibility study for the search of supersymmetric dark matter in the final state of two vector boson fusion jets and large missing transverse energy is presented at 14 TeV. Prospects for determining the dark matter relic density are studied for the cases of wino and bino-Higgsino dark matter. The LHC could probe wino dark matter with mass up to approximately 600 GeV with a luminosity of $1000{\mathrm{fb}}^{-1}$.

Figure 1

Production cross section as a function of $m_{{\tilde{\chi }}_1^0}$ after requiring $|\Delta \eta (j_1,j_2)|>4.2$, at LHC8 and LHC14. For the pure wino and Higgsino cases, inclusive ${\tilde{\chi }}_1^0{\tilde{\chi }}_1^0$, ${\tilde{\chi }}_1^{\pm }{\tilde{\chi }}_1^{\pm }$, ${\tilde{\chi }}_1^{\pm }{\tilde{\chi }}_1^{\mp }$, and ${\tilde{\chi }}_1^{\pm }{\tilde{\chi }}_1^0$ production cross sections are displayed.

Figure 2

Distribution of the dijet invariant mass $M_{j_1{j}_2}$ normalized to unity for the tagging jet pair ($j_1$, $j_2$) and main sources of background after preselection cuts and requiring $p_T>50\mathrm{GeV}$ for the tagging jets at LHC14. The dashed black curves show the distribution for the case where ${\tilde{\chi }}_1^0$ is a nearly pure wino with $m_{{\tilde{\chi }}_1^0}=50$ and 100 GeV. Inclusive ${\tilde{\chi }}_1^0{\tilde{\chi }}_1^0$, ${\tilde{\chi }}_1^{\pm }{\tilde{\chi }}_1^{\pm }$, ${\tilde{\chi }}_1^{\pm }{\tilde{\chi }}_1^{\mp }$, and ${\tilde{\chi }}_1^{\pm }{\tilde{\chi }}_1^0$ production is considered.

Figure 3

The ${\mathrm{E̸}}_T$ distributions for wino DM (50 and 100 GeV) compared to $W+\mathrm{\text{jets}}$ and $Z+\mathrm{\text{jets}}$ events with $500{\mathrm{fb}}^{-1}$ integrated luminosity at LHC14. The distributions are after all selections except the ${\mathrm{E̸}}_T$ cut. Inclusive ${\tilde{\chi }}_1^0{\tilde{\chi }}_1^0$, ${\tilde{\chi }}_1^{\pm }{\tilde{\chi }}_1^{\pm }$, ${\tilde{\chi }}_1^{\pm }{\tilde{\chi }}_1^{\mp }$, and ${\tilde{\chi }}_1^{\pm }{\tilde{\chi }}_1^0$ production is considered.

Figure 4

Significance curves for the case where ${\tilde{\chi }}_1^0$ is 99% wino as a function of $m_{{\tilde{\chi }}_1^0}$ mass for different luminosities at LHC14. The solid gray (green) lines correspond to $3\sigma$ and $5\sigma$ significances.

Figure 5

Contour lines in the relic density-$m_{{\tilde{\chi }}_1^0}$ plane for 99% wino (blue dashed) and 99% Higgsino (gray dotted) DMs expected with $500{\mathrm{fb}}^{-1}$ of luminosity at LHC14. The relic density is normalized to its value at $m_{{\tilde{\chi }}_1^0}=100\mathrm{GeV}$.