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Search for supersymmetry in events containing a same-flavour opposite-sign dilepton pair, jets, and large missing transverse momentum in $\sqrt{s}=8$  TeV pp collisions with the ATLAS detector

The ATLAS collaboration
Eur.Phys.J. C75 (2015) 318, 2015

Abstract (data abstract)
CERN-LHC. Two searches for supersymmetric particles in final states containing a same-flavour opposite-sign lepton pair, jets and large missing transverse momentum are presented. The proton-proton collision data used in these searches were collected at a centre-of-mass energy $\sqrt{s}=8$ TeV by the ATLAS detector at the Large Hadron Collider and corresponds to an integrated luminosity of 20.3 fb$^{-1}$. Two leptonic production mechanisms are considered: decays of squarks and gluinos with $Z$ bosons in the final state, resulting in a peak in the dilepton invariant mass distribution around the $Z$-boson mass; and decays of neutralinos (e.g. $\tilde{\chi}^{0}_{2} \rightarrow \ell^{+}\ell^{-}\tilde{\chi}^{0}_{1}$), resulting in a kinematic endpoint in the dilepton invariant mass distribution. For the former, an excess of events above the expected Standard Model background is observed, with a significance of 3 standard deviations. In the latter case, the data are well-described by the expected Standard Model background. The results from each channel are interpreted in the context of several supersymmetric models involving the production of squarks and gluinos.

  • Table 1

    Data from Figure 6a

    10.17182/hepdata.67921.v1/t1

    The observed and expected dielectron invariant mass distribution in SR-Z. The negigible estimated contribution from Z+jets is omitted in these...

  • Table 2

    Data from Figure 6b

    10.17182/hepdata.67921.v1/t2

    The observed and expected dimuon invariant mass distribution in SR-Z. The negigible estimated contribution from Z+jets is omitted in these...

  • Table 3

    Data from Figure 6c

    10.17182/hepdata.67921.v1/t3

    The observed and expected $E_T^{miss}$ distribution in the dielectron SR-Z. The negigible estimated contribution from Z+jets is omitted in these...

  • Table 4

    Data from Figure 6d

    10.17182/hepdata.67921.v1/t4

    The observed and expected $E_T^{miss}$ distribution in the dimuon SR-Z. The negigible estimated contribution from Z+jets is omitted in these...

  • Table 5

    Data from Figure 9a

    10.17182/hepdata.67921.v1/t5

    The observed and expected dielectron invariant mass distribution in SR-loose. The last bin contains the overflow.

  • Table 6

    Data from Figure 9b

    10.17182/hepdata.67921.v1/t6

    The observed and expected dimuon invariant mass distribution in SR-loose. The last bin contains the overflow.

  • Table 7

    Data from Figure 9c

    10.17182/hepdata.67921.v1/t7

    The observed and expected dielectron invariant mass distribution in the two-jet $b$-veto SR. The last bin contains the overflow.

  • Table 8

    Data from Figure 9d

    10.17182/hepdata.67921.v1/t8

    The observed and expected dimuon invariant mass distribution in the two-jet $b$-veto SR. The last bin contains the overflow.

  • Table 9

    Data from Figure 9e

    10.17182/hepdata.67921.v1/t9

    The observed and expected dielectron invariant mass distribution in the four jet b-veto SR. The last bin contains the overflow.

  • Table 10

    Data from Figure 9f

    10.17182/hepdata.67921.v1/t10

    The observed and expected dimuon invariant mass distribution in the four-jet $b$-veto SR. The last bin contains the overflow.

  • Table 11

    Data from Figure 10a

    10.17182/hepdata.67921.v1/t11

    The observed and expected dielectron invariant mass distribution in the two-jet $b$-tag SR. The last bin contains the overflow.

  • Table 12

    Data from Figure 10b

    10.17182/hepdata.67921.v1/t12

    The observed and expected dimuon invariant mass distribution in two-jet $b$-tag SR. The last bin contains the overflow.

  • Table 13

    Data from Figure 10c

    10.17182/hepdata.67921.v1/t13

    The observed and expected dielectron invariant mass distribution in the four-jet $b$-tag SR. The last bin contains the overflow.

  • Table 14

    Data from Figure 10d

    10.17182/hepdata.67921.v1/t14

    The observed and expected dimuon invariant mass distribution in the four-jet $b$-tag SR. The last bin contains the overflow.

  • Table 15

    Data from Figure 12a

    10.17182/hepdata.67921.v1/t15

    Expected 95% exclusion contour for the GGM model with $\tan(\beta)=1.5$ in SR-Z.

  • Table 16

    Data from Figure 12a

    10.17182/hepdata.67921.v1/t16

    Observed 95% exclusion contour for the GGM model with $\tan(\beta)=1.5$ in SR-Z.

  • Table 17

    Data from Figure 12b

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    Expected 95% exclusion contour for the GGM model with $\tan(\beta)=30$ in SR-Z.

  • Table 18

    Data from Figure 12b

    10.17182/hepdata.67921.v1/t18

    Observed 95% exclusion contour for the GGM model with $\tan(\beta)=30$ in SR-Z.

  • Table 19

    Data from Figure 13a

    10.17182/hepdata.67921.v1/t19

    Expected 95% exclusion contour for the two-step first- and second-generation squark simplified model with sleptons in the two-jet $b$-veto SR.

  • Table 20

    Data from Figure 13a

    10.17182/hepdata.67921.v1/t20

    Observed 95% exclusion contour for the two-step first- and second-generation squark simplified model with sleptons in the two-jet $b$-veto SR.

  • Table 21

    Data from Figure 13b

    10.17182/hepdata.67921.v1/t21

    Expected 95% exclusion contour for the two-step gluino simplified model with sleptons in the four-jet $b$-veto SR.

  • Table 22

    Data from Figure 13b

    10.17182/hepdata.67921.v1/t22

    Observed 95% exclusion contour for the two-step gluino simplified model with sleptons in the four-jet $b$-veto SR.

  • Table 23

    Data from Auxiliary Figure 1a

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    Number of generated events in the two-step gluino simplified model with sleptons.

  • Table 24

    Data from Auxiliary Figure 1b

    10.17182/hepdata.67921.v1/t24

    Production cross-section in the two-step gluino simplified model with sleptons.

  • Table 25

    Data from Auxiliary Figure 2a

    10.17182/hepdata.67921.v1/t25

    Number of generated events in the two-step first- and second-generation squark simplified model with sleptons.

  • Table 26

    Data from Auxiliary Figure 2b

    10.17182/hepdata.67921.v1/t26

    Production cross-section in the two-step first- and second-generation squark simplified model with sleptons.

  • Table 27

    Data from Auxiliary Figure 3a

    10.17182/hepdata.67921.v1/t27

    Number of generated events in the GGM model with $\tan(\beta)=1.5$.

  • Table 28

    Data from Auxiliary Figure 3b

    10.17182/hepdata.67921.v1/t28

    Production cross-section in the GGM model with $\tan(\beta)=1.5$.

  • Table 29

    Data from Auxiliary Figure 4a

    10.17182/hepdata.67921.v1/t29

    Number of generated events in the GGM model with $\tan(\beta)=30$.

  • Table 30

    Data from Auxiliary Figure 4b

    10.17182/hepdata.67921.v1/t30

    Production cross-section in the GGM model with $\tan(\beta)=30$.

  • Table 31

    Data from Auxiliary Figure 5

    10.17182/hepdata.67921.v1/t31

    Total experimental uncertainty [%] for the two-step gluino simplified model with sleptons.

  • Table 32

    Data from Auxiliary Figure 6a

    10.17182/hepdata.67921.v1/t32

    Total experimental uncertainty [%] for the GGM model with $\tan(\beta)=1.5$.

  • Table 33

    Data from Auxiliary Figure 6b

    10.17182/hepdata.67921.v1/t33

    Total experimental uncertainty for the GGM model with $\tan(\beta)=30$.

  • Table 34

    Data from Auxiliary Figure 9a

    10.17182/hepdata.67921.v1/t34

    Signal acceptance for the GGM model with $\tan(\beta)=1.5$ in the combined electron and muon SR-Z.

  • Table 35

    Data from Auxiliary Figure 9b

    10.17182/hepdata.67921.v1/t35

    Signal acceptance for the GGM model with $\tan(\beta)=30$ in the combined electron and muon SR-Z.

  • Table 36

    Data from Auxiliary Figure 10a

    10.17182/hepdata.67921.v1/t36

    Signal efficiency for the GGM model with $\tan(\beta)=1.5$ in the dielectron SR-Z.

  • Table 37

    Data from Auxiliary Figure 10b

    10.17182/hepdata.67921.v1/t37

    Signal efficiency for the GGM model with $\tan(\beta)=30$ in the dielectron SR-Z.

  • Table 38

    Data from Auxiliary Figure 11a

    10.17182/hepdata.67921.v1/t38

    Signal efficiency for the GGM model with $\tan(\beta)=1.5$ in the dimuon SR-Z.

  • Table 39

    Data from Auxiliary Figure 11b

    10.17182/hepdata.67921.v1/t39

    Signal efficiency for the GGM model with $\tan(\beta)=30$ in the dimuon SR-Z.

  • Table 40

    Data from Auxiliary Figure 12a

    10.17182/hepdata.67921.v1/t40

    Signal efficiency for the GGM model with $\tan(\beta)=1.5$ in the electron and muon combined SR-Z.

  • Table 41

    Data from Auxiliary Figure 12b

    10.17182/hepdata.67921.v1/t41

    Signal efficiency for the GGM model with $\tan(\beta)=30$ in the the electron and muon combined SR-Z.

  • Table 42

    Data from Auxiliary Figure 13a

    10.17182/hepdata.67921.v1/t42

    Signal acceptance for the two-step first- and second-generation squarks simplified model with sleptons in the two-jet $b$-veto SR.

  • Table 43

    Data from Auxiliary Figure 13b

    10.17182/hepdata.67921.v1/t43

    Signal acceptance for the two-step gluino simplified model with sleptons in the four-jet $b$-veto SR.

  • Table 44

    Data from Auxiliary Figure 14a

    10.17182/hepdata.67921.v1/t44

    Signal efficiency for the two-step first- and second-generation squarks simplified model with sleptons in the two-jet $b$-veto SR.

  • Table 45

    Data from Auxiliary Figure 14b

    10.17182/hepdata.67921.v1/t45

    Signal efficiency for the two-step gluino simplified model with sleptons in the four-jet $b$-veto SR.

  • Table 46

    Data from Auxiliary Figure 15a

    10.17182/hepdata.67921.v1/t46

    Upper limits on the signal cross-section at 95% CL for the GGM model with $\tan(\beta)=1.5$.

  • Table 47

    Data from Auxiliary Figure 16a

    10.17182/hepdata.67921.v1/t47

    Observed CL$_{\text{S}}$ for the GGM model with $\tan(\beta)=1.5$.

  • Table 48

    Data from Auxiliary Figure 16b

    10.17182/hepdata.67921.v1/t48

    Expected CL$_{\text{S}}$ for the GGM model with $\tan(\beta)=1.5$.

  • Table 49

    Data from Auxiliary Figure 15b

    10.17182/hepdata.67921.v1/t49

    Upper limits on the signal cross-section at 95% CL for the GGM model with $\tan(\beta)=30$.

  • Table 50

    Data from Auxiliary Figure 17a

    10.17182/hepdata.67921.v1/t50

    Observed CL$_{\text{S}}$ for the GGM model with $\tan(\beta)=30$.

  • Table 51

    Data from Auxiliary Figure 17b

    10.17182/hepdata.67921.v1/t51

    Expected CL$_{\text{S}}$ for the GGM model with $\tan(\beta)=30$.

  • Table 52

    Data from Auxiliary Figure 18a

    10.17182/hepdata.67921.v1/t52

    Upper limits on the signal stength at 95% CL for the two-step first- and second-generation squark simplified model with sleptons....

  • Table 53

    Data from Auxiliary Figure 18b

    10.17182/hepdata.67921.v1/t53

    Upper limits on the signal stength at 95% CL for the two-step gluino simplified model with sleptons. The excluded signal...

  • Table 54

    Data from Auxiliary Figure 19a

    10.17182/hepdata.67921.v1/t54

    Observed CL$_{\text{S}}$ for the two-step first- and second-generation squark simplified model with sleptons.

  • Table 55

    Data from Auxiliary Figure 19b

    10.17182/hepdata.67921.v1/t55

    Expected CL$_{\text{S}}$ for the two-step first- and second-generation squark simplified model with sleptons.

  • Table 56

    Data from Auxiliary Figure 20a

    10.17182/hepdata.67921.v1/t56

    Observed CL$_{\text{S}}$ for the two-step gluino simplified model with sleptons.

  • Table 57

    Data from Auxiliary Figure 20b

    10.17182/hepdata.67921.v1/t57

    Expected CL$_{\text{S}}$ for the two-step gluino simplified model with sleptons.

  • Table 58

    Data from Auxiliary Table 1

    10.17182/hepdata.67921.v1/t58

    Cutflow table for three benchmark signal points in SR-Z for the $ee$ and $\mu\mu$ channels separately. The three signal points...

  • Table 59

    Data from Auxiliary Table 2

    10.17182/hepdata.67921.v1/t59

    Cutflow table for three benchmark signal points in the two jet b-veto SR of the off-$Z$ search for the $ee$...

  • Table 60

    Data from Auxiliary Table 3

    10.17182/hepdata.67921.v1/t60

    Cutflow table for three benchmark signal points in the four jet b-veto SR of the off-$Z$ search for the $ee$...

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