• Browse all
Search for supersymmetry in final states with two or three soft leptons and missing transverse momentum in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The collaboration
CMS-SUS-18-004, 2021.

Abstract (data abstract)
A search for supersymmetry in events with two or three low-momentum leptons and missing transverse momentum is performed. The search uses proton-proton collisions at $\sqrt{s} = 13~\text{TeV}$ collected in the three-year period $2016-2018$ by the CMS experiment at the LHC and corresponding to an integrated luminosity of up to $137~\text{fb}^{-1}$. The data are found to be in agreement with expectations from standard model processes. The results are interpreted in terms of electroweakino and top squark pair production with a small mass difference between the produced supersymmetric particles and the lightest neutralino. For the electroweakino interpretation, two simplified models are used, a wino-bino model and a higgsino model. Exclusion limits at $95\%$ confidence level are set on $\tilde{\chi}^0_2/\tilde{\chi}^\pm_1$ masses up to $275~\text{GeV}$ for a mass difference of $10~\text{GeV}$ in the wino-bino case, and up to $205(150)~\text{GeV}$ for a mass difference of $7.5(3)~\text{GeV}$ in the higgsino case. The results for the higgsino are further interpreted using a phenomenological minimal supersymmetric standard model, excluding the higgsino mass parameter $\mu$ up to $180~\text{GeV}$ with the bino mass parameter $M_1$ at $800~\text{GeV}$. In the top squark interpretation, exclusion limits are set at top squark masses up to $540~\text{GeV}$ for four-body top squark decays and up to $480~\text{GeV}$ for chargino-mediated decays with a mass difference of $30~\text{GeV}$.

• #### Figure 2a

Data from Figure 2 (upper left).

10.17182/hepdata.114415.v1/t1

The post-fit distribution of the $M(\ell\ell)$ variable is shown for the low-MET bin for the DY CR. Uncertainties include both...

• #### Figure 2b

Data from Figure 2 (upper right).

10.17182/hepdata.114415.v1/t2

The post-fit distribution of the $M(\ell\ell)$ variable is shown for the high-MET bin for the DY CR. Uncertainties include both...

• #### Figure 2c

Data from Figure 2 (lower left).

10.17182/hepdata.114415.v1/t3

The post-fit distribution of the $M(\ell\ell)$ variable is shown for the low-MET bin for the $\text{t}\bar{\text{t}}$ CR. Uncertainties include both...

• #### Figure 2d

Data from Figure 2 (lower right).

10.17182/hepdata.114415.v1/t4

The post-fit distribution of the $M(\ell\ell)$ variable is shown for the high-MET bin for the $\text{t}\bar{\text{t}}$ CR. Uncertainties include both...

• #### Figure 3a

Data from Figure 3 (left).

10.17182/hepdata.114415.v1/t5

The post-fit distribution of the $M(\ell\ell)$ variable is shown for the low-MET bin for the WZ-enriched region. Uncertainties include both...

• #### Figure 3b

Data from Figure 3 (right).

10.17182/hepdata.114415.v1/t6

The post-fit distribution of the $M(\ell\ell)$ variable is shown for the high-MET bin for the WZ-enriched region. Uncertainties include both...

• #### Figure 4

Data from Figure 4.

10.17182/hepdata.114415.v1/t7

The post-fit distribution of the $M(\ell\ell)$ variable is shown for the high-MET bin for the SS CR. Uncertainties include both...

• #### Figure 5a

Data from Figure 5 (upper left).

10.17182/hepdata.114415.v1/t8

The 2$\ell$-Ewk SR: the post-fit distribution of the $M(\ell\ell)$ variable is shown for the low-MET bin. Uncertainties include both the...

• #### Figure 5b

Data from Figure 5 (upper right).

10.17182/hepdata.114415.v1/t9

The 2$\ell$-Ewk SR: the post-fit distribution of the $M(\ell\ell)$ variable is shown for the med-MET bin. Uncertainties include both the...

• #### Figure 5c

Data from Figure 5 (lower left).

10.17182/hepdata.114415.v1/t10

The 2$\ell$-Ewk SR: the post-fit distribution of the $M(\ell\ell)$ variable is shown for the high-MET bin. Uncertainties include both the...

• #### Figure 5d

Data from Figure 5 (lower right).

10.17182/hepdata.114415.v1/t11

The 2$\ell$-Ewk SR: the post-fit distribution of the $M(\ell\ell)$ variable is shown for the ultra-MET bin. Uncertainties include both the...

• #### Figure 6a

Data from Figure 6 (left).

10.17182/hepdata.114415.v1/t12

The 3$\ell$-Ewk search regions: the post-fit distribution of the $M^{\text{min}}_{\text{SFOS}}(\ell\ell)$ variable is shown for the low-MET bin. Uncertainties include both...

• #### Figure 6b

Data from Figure 6 (right).

10.17182/hepdata.114415.v1/t13

The 3$\ell$-Ewk search regions: the post-fit distribution of the $M^{\text{min}}_{\text{SFOS}}(\ell\ell)$ variable is shown for the high-MET bin. Uncertainties include both...

• #### Figure 7a

Data from Figure 7 (upper left).

10.17182/hepdata.114415.v1/t14

The 2$\ell$-Stop SR: the post-fit distribution of the leading lepton $p_{T}$ variable is shown for the low-MET bin. Uncertainties include...

• #### Figure 7b

Data from Figure 7 (upper right).

10.17182/hepdata.114415.v1/t15

The 2$\ell$-Stop SR: the post-fit distribution of the leading lepton $p_{T}$ variable is shown for the med-MET bin. Uncertainties include...

• #### Figure 7c

Data from Figure 7 (lower left).

10.17182/hepdata.114415.v1/t16

The 2$\ell$-Stop SR: the post-fit distribution of the leading lepton $p_{T}$ variable is shown for the high-MET bin. Uncertainties include...

• #### Figure 7d

Data from Figure 7 (lower right).

10.17182/hepdata.114415.v1/t17

The 2$\ell$-Stop SR: the post-fit distribution of the leading lepton $p_{T}$ variable is shown for the ultra-MET bin. Uncertainties include...

• #### Figure 8a

Data from Figure 8 (upper).

10.17182/hepdata.114415.v1/t18

The observed 95% CL exclusion contours (black curves) assuming the NLO+NLL cross sections, with the variations (thin lines) corresponding to...

• #### Figure 8b

Data from Figure 8 (lower).

10.17182/hepdata.114415.v1/t19

The observed 95% CL exclusion contours (black curves) assuming the NLO+NLL cross sections, with the variations (thin lines) corresponding to...

• #### Figure 9a

Data from Figure 9 (upper).

10.17182/hepdata.114415.v1/t20

The observed 95% CL exclusion contours (black curves) assuming the NLO+NLL cross sections, with the variations (thin lines) corresponding to...

• #### Figure 9b

Data from Figure 9 (lower).

10.17182/hepdata.114415.v1/t21

The observed 95% CL exclusion contours (black curves) assuming the NLO+NLL cross sections, with the variations (thin lines) corresponding to...

• #### Figure 10a

Data from Figure 10 (upper).

10.17182/hepdata.114415.v1/t22

The observed 95% CL exclusion contours (black curves) assuming the NLO+NLL cross sections, with the variations (thin lines) corresponding to...

• #### Figure 10b

Data from Figure 10 (lower).

10.17182/hepdata.114415.v1/t23

The observed 95% CL exclusion contours (black curves) assuming the NLO+NLL cross sections, with the variations (thin lines) corresponding to...