Search for long-lived particles with displaced vertices in multijet events in proton-proton collisions at $\sqrt{s}= $13 TeV

The CMS collaboration
Phys.Rev. D98 (2018) 092011, 2018

Abstract (data abstract)
Results are reported from a search for long-lived particles in proton-proton collisions at $\sqrt{s}$ = 13 TeV delivered by the CERN LHC and collected by the CMS experiment. The data sample, which was recorded during 2015 and 2016, corresponds to an integrated luminosity of $38.5~\textrm{fb}^{-1}$. This search uses benchmark signal models in which long-lived particles are pair-produced and each decays into two or more quarks, leading to a signal with multiple jets and two displaced vertices composed of many tracks. No events with two well-separated high-track-multiplicity vertices are observed. Upper limits are placed on models of $R$-parity violating supersymmetry in which the long-lived particles are neutralinos or gluinos decaying solely into multijet final states or top squarks decaying solely into dijet final states. For neutralino, gluino, or top squark masses between 800 and 2600 GeV and mean proper decay lengths between 1 and 40 mm, the analysis excludes cross sections above 0.3 fb at 95% confidence level. Gluino and top squark masses are excluded below 2200 and 1400 GeV, respectively, for mean proper decay lengths between 0.6 and 80 mm. A method is provided for extending the results to other models with pair-produced long-lived particles.

  • Figure 2

    Figure 2

    10.17182/hepdata.85138.v1/t1

    Distribution of the distance between vertices in the $x$-$y$ plane, $d_{VV}$, for simulated multijet signals with $m$ = 800 GeV,...

  • Figure 3a

    Figure 3a (upper plot)

    10.17182/hepdata.85138.v1/t2

    Signal efficiency as a function of signal mass and lifetime for the multijet signal samples. All vertex and event selection...

  • Figure 3b

    Figure 3b (lower plot)

    10.17182/hepdata.85138.v1/t3

    Signal efficiency as a function of signal mass and lifetime for the dijet signal samples. All vertex and event selection...

  • Figure 4

    Figure 4

    10.17182/hepdata.85138.v1/t4

    Distribution of $d_{BV}$ in $\geq$5-track one-vertex events for data and simulated multijet signals with $m$ = 800 GeV, production cross...

  • Figure 5a

    Figure 5a (upper left plot)

    10.17182/hepdata.85138.v1/t5

    Distribution of the distance between vertices in the $x$-$y$ plane in events with two 3-track vertices. The points show the...

  • Figure 5b

    Figure 5b (upper right plot)

    10.17182/hepdata.85138.v1/t6

    Distribution of the distance between vertices in the $x$-$y$ plane in events with one 4-track vertex and one 3-track vertex....

  • Figure 5c

    Figure 5c (lower left plot)

    10.17182/hepdata.85138.v1/t7

    Distribution of the distance between vertices in the $x$-$y$ plane in events with two 4-track vertices. The points show the...

  • Figure 5d

    Figure 5d (lower right plot)

    10.17182/hepdata.85138.v1/t8

    Distribution of the distance between vertices in the $x$-$y$ plane in events with two $\geq$5-track vertices. The points show the...

  • Figure 6a (grid of limit values)

    Figure 6a (left upper and lower plots, grid of limit values)

    10.17182/hepdata.85138.v1/t9

    Observed 95% C.L. upper limits on $\sigma\mathcal{B}^2$ for the multijet signals as a function of mass and mean proper decay...

  • Figure 6b (grid of limit values)

    Figure 6b (right upper and lower plots, grid of limit values)

    10.17182/hepdata.85138.v1/t10

    Observed 95% C.L. upper limits on $\sigma\mathcal{B}^2$ for the dijet signals as a function of mass and mean proper decay...

  • Figure 6a (mass exclusion curves)

    Figure 6a (left upper and lower plots, mass exclusion curves)

    10.17182/hepdata.85138.v1/t11

    Mass exclusion curves for the multijet signals, assuming gluino pair production cross sections and 100% branching fraction.

  • Figure 6b (mass exclusion curves)

    Figure 6b (right upper and lower plots, mass exclusion curves)

    10.17182/hepdata.85138.v1/t12

    Mass exclusion curves for the dijet signals, assuming top squark pair production cross sections and 100% branching fraction.

  • Figure 7a

    Figure 7a (upper left plot)

    10.17182/hepdata.85138.v1/t13

    Observed and expected 95% C.L. upper limits on $\sigma\mathcal{B}^2$ for the multijet signals as a function of mass for a...

  • Figure 7b

    Figure 7b (upper right plot)

    10.17182/hepdata.85138.v1/t14

    Observed and expected 95% C.L. upper limits on $\sigma\mathcal{B}^2$ for the dijet signals as a function of mass for a...

  • Figure 7c

    Figure 7c (middle left plot)

    10.17182/hepdata.85138.v1/t15

    Observed and expected 95% C.L. upper limits on $\sigma\mathcal{B}^2$ for the multijet signals as a function of mass for a...

  • Figure 7d

    Figure 7d (middle right plot)

    10.17182/hepdata.85138.v1/t16

    Observed and expected 95% C.L. upper limits on $\sigma\mathcal{B}^2$ for the dijet signals as a function of mass for a...

  • Figure 7e

    Figure 7e (lower left plot)

    10.17182/hepdata.85138.v1/t17

    Observed and expected 95% C.L. upper limits on $\sigma\mathcal{B}^2$ for the multijet signals as a function of mass for a...

  • Figure 7f

    Figure 7f (lower right plot)

    10.17182/hepdata.85138.v1/t18

    Observed and expected 95% C.L. upper limits on $\sigma\mathcal{B}^2$ for the dijet signals as a function of mass for a...

  • Figure 8a

    Figure 8a (upper left plot)

    10.17182/hepdata.85138.v1/t19

    Observed and expected 95% C.L. upper limits on $\sigma\mathcal{B}^2$ for the multijet signals as a function of $c\tau$ for a...

  • Figure 8b

    Figure 8b (upper right plot)

    10.17182/hepdata.85138.v1/t20

    Observed and expected 95% C.L. upper limits on $\sigma\mathcal{B}^2$ for the dijet signals as a function of $c\tau$ for a...

  • Figure 8c

    Figure 8c (middle left plot)

    10.17182/hepdata.85138.v1/t21

    Observed and expected 95% C.L. upper limits on $\sigma\mathcal{B}^2$ for the multijet signals as a function of $c\tau$ for a...

  • Figure 8d

    Figure 8d (middle right plot)

    10.17182/hepdata.85138.v1/t22

    Observed and expected 95% C.L. upper limits on $\sigma\mathcal{B}^2$ for the dijet signals as a function of $c\tau$ for a...

  • Figure 8e

    Figure 8e (lower left plot)

    10.17182/hepdata.85138.v1/t23

    Observed and expected 95% C.L. upper limits on $\sigma\mathcal{B}^2$ for the multijet signals as a function of $c\tau$ for a...

  • Figure 8f

    Figure 8f (lower right plot)

    10.17182/hepdata.85138.v1/t24

    Observed and expected 95% C.L. upper limits on $\sigma\mathcal{B}^2$ for the dijet signals as a function of $c\tau$ for a...

Loading Data...