Electroweak Dark Matter at Future Hadron Colliders

In a large class of scenarios, dark matter (DM) particles that belong to a multiplet of the standard model (SM) weak interactions are challenging to probe in direct detection experiments due to loop-suppressed cross-sections. Direct production at colliders is thus crucial to look for such DM candidates, and under current estimates, future runs of the 14-TeV LHC are projected to probe masses of around 300 GeV for DM belonging to an SU(2) doublet (Higgsino-like), and 900 GeV for SU(2) triplet (wino-like). We examine how far this mass reach can be extended at the proposed 27-TeV high-energy upgrade of the LHC (HE-LHC), and compare the results to the case for a 100-TeV hadron collider. Following a detector setup similar to that of the ATLAS tracking system for the Run-2 LHC upgrade, with a new Insertable B-Layer (IBL), a disappearing charged track analysis at the HE-LHC can probe Higgsino-like (wino-like) DM mass of up to 600 GeV (2.1 TeV) at the 95% C.L. The monojet and missing transverse momentum search, on the otherhand, has a weaker reach of 490 GeV (700 GeV) at 95% C.L. for the Higgsino-like (wino-like) states. The mass range accessible in the collider searches can be complementary to the indirect detection probes using gamma rays from dwarf-spheroidal galaxies.

6 4 Indirect Detection Constraints on Neutralino Dark M Data from indirect detection can place significant constraints on any dark matter ca SU(2) L multiplet, due to the annihilation 0 0 ! W + W (and ZZ, depending on tation), which leads to copious production of gamma rays and antiprotons [4]. Thes e↵ective even for very small mass splittings within the SU(2) L multiplet, and thus ar tary to direct detection. Here we will present the current constraints on a few scen wino and pure higgsino dark matter. For the computation of wino annihilation, th enhancement is crucial [52], and the one loop annihilation process 0 0 ! ma tectable [53,54]. As a result, in recent years sophisticated e↵ective field theory te been applied to more accurate computation of these annihilation processes [55][56][57][58][59][60] the case of gamma ray line searches.  to be of the order of O(10 2 ) to O(10 1 ). The p T spectra of the lepton control transfer factors, then convolved with the smearing function. Two di erent p T for the high-E miss T and one for the low-E miss T region, while keeping the same req region.
Fake tracklets: Fake tracklets are tracklets which are seeded from a random d 0 distribution of fake tracklets is broad, whereas the high-p T chargino track resolution and therefore have values of d 0 which cluster around zero. The fake defined by requiring |d 0 |/ (d 0 ) > 10, and by removing the E miss T requirement. by fake tracklets. The p T spectrum of fake tracklets is modelled with the follow form: where p 0 and p 1 are fit parameters. Figure 6 shows the p T distribution of p control region with the result of the fit. The p T spectrum shape is confirmed to b comparing it in three E miss

Signal and background templates
The main SM background processes for the two analysis channels are from tt and W +jets (with W ! e⌫, production, where the electrons or the hadrons, usually pions, come from the ⌧ leptons. Hadrons or lept can be classified as a tracklet if they interact with the detector material and any hits in the tracking detect after the pixel detector are not associated to the reconstructed track. This may happen because of sev multiple-scattering, hadronic interactions or, in the case of leptons, bremsstrahlung. Another categ of background is fake tracklets, which originate from random combinations of hits from more than t particles. A schematic view of the three background categories are shown in Figure 4. Templates for these backgroud components are estimated from data. The p T spectra of hadrons and lept scattered by the ID material are estimated from the p T distribution of tracks associated to non-scatte hadrons and leptons, selected in dedicated control samples, by smearing them to take into account poor p T resolution of pixel tracklets. The p T spectrum shape of the fake component is also obtained i  to be of the order of O(10 2 ) to O(10 1 ). The p T spectra of the lepton control samp transfer factors, then convolved with the smearing function. Two di erent p T spec for the high-E miss T and one for the low-E miss T region, while keeping the same requirem region.
Fake tracklets: Fake tracklets are tracklets which are seeded from a random com d 0 distribution of fake tracklets is broad, whereas the high-p T chargino tracklets resolution and therefore have values of d 0 which cluster around zero. The fake track defined by requiring |d 0 |/ (d 0 ) > 10, and by removing the E miss T requirement. This by fake tracklets. The p T spectrum of fake tracklets is modelled with the following form: where p 0 and p 1 are fit parameters. Figure 6 shows the p T distribution of pixel control region with the result of the fit. The p T spectrum shape is confirmed to be ind comparing it in three E miss  • Require that / E T > 90 GeV.
• If there are any other jets with p T (j 2 ) > 45 GeV, the hardest of these is considered the second jet.
• Compute the azimuthal separation, (j, / E T ), between the missing energy and the hardest jet. If there is a second jet and its azimuthal separation from the missing energy is smaller, use that instead. Only keep events where min (j, / E T ) > 1.5.
• There must be at least chargino track that is isolated and satisfies a track selection criteria and 0.1 < |⌘ track | < 1.9.
• Signal regions are defined by a p T cut on the chargino track. The bins are p track T > 75 GeV, p track