Searches for electroweak production of supersymmetric particles with compressed mass spectra in $\sqrt{s}=13$ TeV $pp$ collisions with the ATLAS detector

The ATLAS collaboration
No Journal Information, 2019

Abstract (data abstract)
This paper presents results of searches for electroweak production of supersymmetric particles in models with compressed mass spectra. The searches use 139/fb of sqrt(s) = 13 TeV proton-proton collision data collected by the ATLAS experiment at the Large Hadron Collider. Events with missing transverse momentum and two same-flavor, oppositely charged, low transverse momentum leptons are selected, and are further categorized by the presence of hadronic activity from initial-state radiation or a topology compatible with vector-boson fusion processes. The data are found to be consistent with predictions from the Standard Model. The results are interpreted using simplified models of R-parity-conserving supersymmetry in which the lightest supersymmetric partner is a neutralino with a mass similar to the lightest chargino, the second-to-lightest neutralino or the slepton. Lower limits on the masses of charginos in different simplified models range from 193 GeV to 240 GeV for moderate mass splittings, and extend down to mass splittings of 1.5 GeV to 2.4 GeV at the LEP chargino bounds (92.4 GeV). Similar lower limits on degenerate light-flavor sleptons extend up to masses of 251 GeV and down to mass splittings of 550 MeV. Constraints on vector-boson fusion production of electroweak SUSY states are also presented.

  • Figure 14a Expected

    Figure 14a

    10.17182/hepdata.91374.v1/t1

    Expected 95% CL exclusion sensitivity for simplified models of direct higgsino production.

  • Figure 14a Observed

    Figure 14a

    10.17182/hepdata.91374.v1/t2

    Observed 95% CL exclusion sensitivity for simplified models of direct higgsino production.

  • Figure 14b Expected

    Figure 14b

    10.17182/hepdata.91374.v1/t3

    Expected 95% CL exclusion sensitivity for simplified models of direct wino-bino production, assuming $m(\tilde{\chi}_{2}^{0}) \times m(\tilde{\chi}_{1}^{0})<0$.

  • Figure 14b Observed

    Figure 14b

    10.17182/hepdata.91374.v1/t4

    Observed 95% CL exclusion sensitivity for simplified models of direct wino-bino production, assuming $m(\tilde{\chi}_{2}^{0}) \times m(\tilde{\chi}_{1}^{0})<0$.

  • Figure 14c Expected

    Figure 14c

    10.17182/hepdata.91374.v1/t5

    Expected 95% CL exclusion sensitivity for simplified models of direct wino-bino production, assuming $m(\tilde{\chi}_{2}^{0}) \times m(\tilde{\chi}_{1}^{0})>0$.

  • Figure 14c Observed

    Figure 14c

    10.17182/hepdata.91374.v1/t6

    Observed 95% CL exclusion sensitivity for simplified models of direct wino-bino production, assuming $m(\tilde{\chi}_{2}^{0}) \times m(\tilde{\chi}_{1}^{0})>0$.

  • Figure 15b Expected

    Figure 15b

    10.17182/hepdata.91374.v1/t7

    Expected 95% CL exclusion sensitivity for simplified models of VBF wino-bino production.

  • Figure 15b Observed

    Figure 15b

    10.17182/hepdata.91374.v1/t8

    Observed 95% CL exclusion sensitivity for simplified models of direct wino-bino production.

  • Figure 16a Expected

    Figure 16a

    10.17182/hepdata.91374.v1/t9

    Expected 95% CL exclusion sensitivity for simplified models of direct slepton production.

  • Figure 16a Observed

    Figure 16a

    10.17182/hepdata.91374.v1/t10

    Observed 95% CL exclusion sensitivity for simplified models of direct slepton production.

  • Figure 16b LH smuon Expected

    Figure 16b

    10.17182/hepdata.91374.v1/t11

    Expected 95% CL exclusion sensitivity for simplified models of direct LH smuon production.

  • Figure 16b LH smuon Observed

    Figure 16b

    10.17182/hepdata.91374.v1/t12

    Observed 95% CL exclusion sensitivity for simplified models of direct LH smuon production.

  • Figure 16b RH smuon Expected

    Figure 16b

    10.17182/hepdata.91374.v1/t13

    Expected 95% CL exclusion sensitivity for simplified models of direct RH smuon production.

  • Figure 16b RH smuon Observed

    Figure 16b

    10.17182/hepdata.91374.v1/t14

    Observed 95% CL exclusion sensitivity for simplified models of direct RH smuon production.

  • Figure 16b LH selectron Expected

    Figure 16b

    10.17182/hepdata.91374.v1/t15

    Expected 95% CL exclusion sensitivity for simplified models of direct LH selectron production.

  • Figure 16b LH selectron Observed

    Figure 16b

    10.17182/hepdata.91374.v1/t16

    Observed 95% CL exclusion sensitivity for simplified models of direct LH selectron production.

  • Figure 16b RH selectron Expected

    Figure 16b

    10.17182/hepdata.91374.v1/t17

    Expected 95% CL exclusion sensitivity for simplified models of direct RH selectron production.

  • Figure 16b RH selectron Observed

    Figure 16b

    10.17182/hepdata.91374.v1/t18

    Observed 95% CL exclusion sensitivity for simplified models of direct RH selectron production.

  • Figure 28a

    Figure 28a

    10.17182/hepdata.91374.v1/t19

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the C1C1 higgsino process in the SR-E-high region. Truth dilepton...

  • Figure 28b

    Figure 28b

    10.17182/hepdata.91374.v1/t20

    Efficiency for the C1C1 higgsino process in the SR-E-high region. Truth dilepton invariant mass is constrained to be within the...

  • Figure 28c

    Figure 28c

    10.17182/hepdata.91374.v1/t21

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the C1C1 higgsino process in the SR-E-low region. Truth dilepton...

  • Figure 28d

    Figure 28d

    10.17182/hepdata.91374.v1/t22

    Efficiency for the C1C1 higgsino process in the SR-E-low region. Truth dilepton invariant mass is constrained to be within the...

  • Figure 28e

    Figure 28e

    10.17182/hepdata.91374.v1/t23

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the C1C1 higgsino process in the SR-E-med region. Truth dilepton...

  • Figure 28f

    Figure 28f

    10.17182/hepdata.91374.v1/t24

    Efficiency for the C1C1 higgsino process in the SR-E-med region. Truth dilepton invariant mass is constrained to be within the...

  • Figure 29a

    Figure 29a

    10.17182/hepdata.91374.v1/t25

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2N1 higgsino process in the SR-E-high region. Truth dilepton...

  • Figure 29b

    Figure 29b

    10.17182/hepdata.91374.v1/t26

    Efficiency for the N2N1 higgsino process in the SR-E-high region. Truth dilepton invariant mass is constrained to be within the...

  • Figure 29c

    Figure 29c

    10.17182/hepdata.91374.v1/t27

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2N1 higgsino process in the SR-E-low region. Truth dilepton...

  • Figure 29d

    Figure 29d

    10.17182/hepdata.91374.v1/t28

    Efficiency for the N2N1 higgsino process in the SR-E-low region. Truth dilepton invariant mass is constrained to be within the...

  • Figure 29e

    Figure 29e

    10.17182/hepdata.91374.v1/t29

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2N1 higgsino process in the SR-E-med region. Truth dilepton...

  • Figure 29f

    Figure 29f

    10.17182/hepdata.91374.v1/t30

    Efficiency for the N2N1 higgsino process in the SR-E-med region. Truth dilepton invariant mass is constrained to be within the...

  • Figure 29g

    Figure 29g

    10.17182/hepdata.91374.v1/t31

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2N1 higgsino process in the SR-E-1l1T region. Truth dilepton...

  • Figure 29h

    Figure 29h

    10.17182/hepdata.91374.v1/t32

    Efficiency for the N2N1 higgsino process in the SR-E-1l1T region. Truth dilepton invariant mass is constrained to be within the...

  • Figure 30a

    Figure 30a

    10.17182/hepdata.91374.v1/t33

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2C1p higgsino process in the SR-E-high region. Truth dilepton...

  • Figure 30b

    Figure 30b

    10.17182/hepdata.91374.v1/t34

    Efficiency for the N2C1p higgsino process in the SR-E-high region. Truth dilepton invariant mass is constrained to be within the...

  • Figure 30c

    Figure 30c

    10.17182/hepdata.91374.v1/t35

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2C1p higgsino process in the SR-E-low region. Truth dilepton...

  • Figure 30d

    Figure 30d

    10.17182/hepdata.91374.v1/t36

    Efficiency for the N2C1p higgsino process in the SR-E-low region. Truth dilepton invariant mass is constrained to be within the...

  • Figure 30e

    Figure 30e

    10.17182/hepdata.91374.v1/t37

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2C1p higgsino process in the SR-E-med region. Truth dilepton...

  • Figure 30f

    Figure 30f

    10.17182/hepdata.91374.v1/t38

    Efficiency for the N2C1p higgsino process in the SR-E-med region. Truth dilepton invariant mass is constrained to be within the...

  • Figure 30g

    Figure 30g

    10.17182/hepdata.91374.v1/t39

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2C1p higgsino process in the SR-E-1l1T region. Truth dilepton...

  • Figure 30h

    Figure 30h

    10.17182/hepdata.91374.v1/t40

    Efficiency for the N2C1p higgsino process in the SR-E-1l1T region. Truth dilepton invariant mass is constrained to be within the...

  • Figure 31a

    Figure 31a

    10.17182/hepdata.91374.v1/t41

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2C1m higgsino process in the SR-E-high region. Truth dilepton...

  • Figure 31b

    Figure 31b

    10.17182/hepdata.91374.v1/t42

    Efficiency for the N2C1m higgsino process in the SR-E-high region. Truth dilepton invariant mass is constrained to be within the...

  • Figure 31c

    Figure 31c

    10.17182/hepdata.91374.v1/t43

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2C1m higgsino process in the SR-E-low region. Truth dilepton...

  • Figure 31d

    Figure 31d

    10.17182/hepdata.91374.v1/t44

    Efficiency for the N2C1m higgsino process in the SR-E-low region. Truth dilepton invariant mass is constrained to be within the...

  • Figure 31e

    Figure 31e

    10.17182/hepdata.91374.v1/t45

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2C1m higgsino process in the SR-E-med region. Truth dilepton...

  • Figure 31f

    Figure 31f

    10.17182/hepdata.91374.v1/t46

    Efficiency for the N2C1m higgsino process in the SR-E-med region. Truth dilepton invariant mass is constrained to be within the...

  • Figure 31g

    Figure 31g

    10.17182/hepdata.91374.v1/t47

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2C1m higgsino process in the SR-E-1l1T region. Truth dilepton...

  • Figure 31h

    Figure 31h

    10.17182/hepdata.91374.v1/t48

    Efficiency for the N2C1m higgsino process in the SR-E-1l1T region. Truth dilepton invariant mass is constrained to be within the...

  • Figure 32a

    Figure 32a

    10.17182/hepdata.91374.v1/t49

    Acceptance (note the $z$-axis is in units of $10^{-3}$) for the slepton process in the SR-S region. Truth stransverse mass...

  • Figure 32b

    Figure 32b

    10.17182/hepdata.91374.v1/t50

    Efficiency for the slepton process in the SR-S region. Truth stransverse mass is constrained to be within the range [100,140]...

  • Figure 32c

    Figure 32c

    10.17182/hepdata.91374.v1/t51

    Acceptance (note the $z$-axis is in units of $10^{-3}$) for the slepton process in the SR-S-high region. Truth stransverse mass...

  • Figure 32d

    Figure 32d

    10.17182/hepdata.91374.v1/t52

    Efficiency for the slepton process in the SR-S-high region. Truth stransverse mass is constrained to be within the range [100,140]...

  • Figure 32e

    Figure 32e

    10.17182/hepdata.91374.v1/t53

    Acceptance (note the $z$-axis is in units of $10^{-3}$) for the slepton process in the SR-S-low region. Truth stransverse mass...

  • Figure 32f

    Figure 32f

    10.17182/hepdata.91374.v1/t54

    Efficiency for the slepton process in the SR-S-low region. Truth stransverse mass is constrained to be within the range [100,140]...

  • Figure 33a

    Figure 33a

    10.17182/hepdata.91374.v1/t55

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the C1C1 VBF higgsino process in the SR-VBF-high region. Truth...

  • Figure 33b

    Figure 33b

    10.17182/hepdata.91374.v1/t56

    Efficiency for the C1C1 VBF higgsino process in the SR-VBF-high region. Truth dilepton invariant mass is constrained to be within...

  • Figure 33c

    Figure 33c

    10.17182/hepdata.91374.v1/t57

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the C1C1 VBF higgsino process in the SR-VBF-low region. Truth...

  • Figure 33d

    Figure 33d

    10.17182/hepdata.91374.v1/t58

    Efficiency for the C1C1 VBF higgsino process in the SR-VBF-low region. Truth dilepton invariant mass is constrained to be within...

  • Figure 33e

    Figure 33e

    10.17182/hepdata.91374.v1/t59

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the C1C1 VBF higgsino process in the SR-VBF region. Truth...

  • Figure 33f

    Figure 33f

    10.17182/hepdata.91374.v1/t60

    Efficiency for the C1C1 VBF higgsino process in the SR-VBF region. Truth dilepton invariant mass is constrained to be within...

  • Figure 34a

    Figure 34a

    10.17182/hepdata.91374.v1/t61

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2N1 VBF higgsino process in the SR-VBF-high region. Truth...

  • Figure 34b

    Figure 34b

    10.17182/hepdata.91374.v1/t62

    Efficiency for the N2N1 VBF higgsino process in the SR-VBF-high region. Truth dilepton invariant mass is constrained to be within...

  • Figure 34c

    Figure 34c

    10.17182/hepdata.91374.v1/t63

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2N1 VBF higgsino process in the SR-VBF-low region. Truth...

  • Figure 34d

    Figure 34d

    10.17182/hepdata.91374.v1/t64

    Efficiency for the N2N1 VBF higgsino process in the SR-VBF-low region. Truth dilepton invariant mass is constrained to be within...

  • Figure 34e

    Figure 34e

    10.17182/hepdata.91374.v1/t65

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2N1 VBF higgsino process in the SR-VBF region. Truth...

  • Figure 34f

    Figure 34f

    10.17182/hepdata.91374.v1/t66

    Efficiency for the N2N1 VBF higgsino process in the SR-VBF region. Truth dilepton invariant mass is constrained to be within...

  • Figure 35a

    Figure 35a

    10.17182/hepdata.91374.v1/t67

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2C1p VBF higgsino process in the SR-VBF-high region. Truth...

  • Figure 35b

    Figure 35b

    10.17182/hepdata.91374.v1/t68

    Efficiency for the N2C1p VBF higgsino process in the SR-VBF-high region. Truth dilepton invariant mass is constrained to be within...

  • Figure 35c

    Figure 35c

    10.17182/hepdata.91374.v1/t69

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2C1p VBF higgsino process in the SR-VBF-low region. Truth...

  • Figure 35d

    Figure 35d

    10.17182/hepdata.91374.v1/t70

    Efficiency for the N2C1p VBF higgsino process in the SR-VBF-low region. Truth dilepton invariant mass is constrained to be within...

  • Figure 35e

    Figure 35e

    10.17182/hepdata.91374.v1/t71

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2C1p VBF higgsino process in the SR-VBF region. Truth...

  • Figure 35f

    Figure 35f

    10.17182/hepdata.91374.v1/t72

    Efficiency for the N2C1p VBF higgsino process in the SR-VBF region. Truth dilepton invariant mass is constrained to be within...

  • Figure 36a

    Figure 36a

    10.17182/hepdata.91374.v1/t73

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2C1m VBF higgsino process in the SR-VBF-high region. Truth...

  • Figure 36b

    Figure 36b

    10.17182/hepdata.91374.v1/t74

    Efficiency for the N2C1m VBF higgsino process in the SR-VBF-high region. Truth dilepton invariant mass is constrained to be within...

  • Figure 36c

    Figure 36c

    10.17182/hepdata.91374.v1/t75

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2C1m VBF higgsino process in the SR-VBF-low region. Truth...

  • Figure 36d

    Figure 36d

    10.17182/hepdata.91374.v1/t76

    Efficiency for the N2C1m VBF higgsino process in the SR-VBF-low region. Truth dilepton invariant mass is constrained to be within...

  • Figure 36e

    Figure 36e

    10.17182/hepdata.91374.v1/t77

    Acceptance (note the $z$-axis is in units of $10^{-4}$) for the N2C1m VBF higgsino process in the SR-VBF region. Truth...

  • Figure 36f

    Figure 36f

    10.17182/hepdata.91374.v1/t78

    Efficiency for the N2C1m VBF higgsino process in the SR-VBF region. Truth dilepton invariant mass is constrained to be within...

  • Figure 41ab

    Figure 41ab

    10.17182/hepdata.91374.v1/t79

    Observed and Expected upper cross-section limits for wino-bino scenarios, assuming $m(\tilde{\chi}_{2}^{0}) \times m(\tilde{\chi}_{1}^{0})>0$.

  • Figure 41cd

    Figure 41cd

    10.17182/hepdata.91374.v1/t80

    Observed and Expected upper cross-section limits for wino-bino scenarios, assuming $m(\tilde{\chi}_{2}^{0}) \times m(\tilde{\chi}_{1}^{0})<0$.

  • Figure 42ab

    Figure 42ab

    10.17182/hepdata.91374.v1/t81

    Observed and Expected upper cross-section limits for higgsino scenarios.

  • Figure 43ab

    Figure 43ab

    10.17182/hepdata.91374.v1/t82

    Observed and Expected upper cross-section limits for higgsino scenarios, assuming VBF production..

  • Figure 44ab

    Figure 44ab

    10.17182/hepdata.91374.v1/t83

    Observed and Expected upper cross-section limits for direct slepton scenarios.

  • Figure 44cd

    Figure 44cd

    10.17182/hepdata.91374.v1/t84

    Observed and Expected upper cross-section limits for direct LH slepton scenarios.

  • Figure 44ef

    Figure 44ef

    10.17182/hepdata.91374.v1/t85

    Observed and Expected upper cross-section limits for direct RH slepton scenarios.

  • Figure 45ab

    Figure 45ab

    10.17182/hepdata.91374.v1/t86

    Observed and Expected upper cross-section limits for direct smuon scenarios.

  • Figure 45cd

    Figure 45cd

    10.17182/hepdata.91374.v1/t87

    Observed and Expected upper cross-section limits for direct LH smuon scenarios.

  • Figure 45ef

    Figure 45ef

    10.17182/hepdata.91374.v1/t88

    Observed and Expected upper cross-section limits for direct RH smuon scenarios.

  • Figure 46ab

    Figure 46ab

    10.17182/hepdata.91374.v1/t89

    Observed and Expected upper cross-section limits for direct selectron scenarios.

  • Figure 46cd

    Figure 46cd

    10.17182/hepdata.91374.v1/t90

    Observed and Expected upper cross-section limits for direct LH selectron scenarios.

  • Figure 46ef

    Figure 46ef

    10.17182/hepdata.91374.v1/t91

    Observed and Expected upper cross-section limits for direct RH selectron scenarios.

  • Table 18

    Table 18

    10.17182/hepdata.91374.v1/t92

    Number of signal events in SR-E-1L1T for the (m($\tilde{\chi}_{2}^{0}$),m($\tilde{\chi}_{1}^{0}$)) = (155 GeV, 150 GeV) Higgsino signal model at different stages...

  • Table 19

    Table 19

    10.17182/hepdata.91374.v1/t93

    Number of signal events in SR-E-high for the (m($\tilde{\chi}_{2}^{0}$),m($\tilde{\chi}_{1}^{0}$)) = (155 GeV, 150 GeV) Higgsino signal model at different stages...

  • Table 20

    Table 20

    10.17182/hepdata.91374.v1/t94

    Number of signal events in SR-E-low for the (m($\tilde{\chi}_{2}^{0}$),m($\tilde{\chi}_{1}^{0}$)) = (155 GeV, 150 GeV) Higgsino signal model at different stages...

  • Table 21

    Table 21

    10.17182/hepdata.91374.v1/t95

    Number of signal events in SR-E-med for the (m($\tilde{\chi}_{2}^{0}$),m($\tilde{\chi}_{1}^{0}$)) = (155 GeV, 150 GeV) Higgsino signal model at different stages...

  • Table 22

    Table 22

    10.17182/hepdata.91374.v1/t96

    Number of signal events in SR-S-high for the (m($\tilde{\ell}$),m($\tilde{\chi}_{1}^{0}$)) = (150 GeV, 140 GeV) Slepton signal model at different stages...

  • Table 23

    Table 23

    10.17182/hepdata.91374.v1/t97

    Number of signal events in SR-S-low for the (m($\tilde{\ell}$),m($\tilde{\chi}_{1}^{0}$)) = (150 GeV, 140 GeV) Slepton signal model at different stages...

  • Table 24

    Table 24

    10.17182/hepdata.91374.v1/t98

    Number of signal events in SR-VBF for the (m($\tilde{\chi}_{2}^{0}$),m($\tilde{\chi}_{1}^{0}$)) = (100 GeV, 95 GeV) Higgsino signal model at different stages...

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