• Browse all
Search for metastable heavy charged particles with large ionisation energy loss in pp collisions at $\sqrt{s} = 8$  TeV using the ATLAS experiment

The ATLAS collaboration
Eur.Phys.J. C75 (2015) 407, 2015

Abstract (data abstract)
Many extensions of the Standard Model predict the existence of charged heavy long-lived particles, such as $R$-hadrons or charginos. These particles, if produced at the Large Hadron Collider, should be moving non-relativistically and are therefore identifiable through the measurement of an anomalously large specific energy loss in the ATLAS pixel detector. Measuring heavy long-lived particles through their track parameters in the vicinity of the interaction vertex provides sensitivity to metastable particles with lifetimes from 0.6 ns to 30 ns. A search for such particles with the ATLAS detector at the Large Hadron Collider is presented, based on a data sample corresponding to an integrated luminosity of 18.4 fb$^{-1}$ of $pp$ collisions at $\sqrt{s}$ = 8 TeV. No significant deviation from the Standard Model background expectation is observed, and lifetime-dependent upper limits on $R$-hadrons and chargino production are set. Gluino $R$-hadrons with 10 ns lifetime and masses up to 1185 GeV are excluded at 95$\%$ confidence level, and so are charginos with 15 ns lifetime and masses up to 482 GeV.

  • Table 1

    Data from Figure 1

    10.17182/hepdata.68640.v1/t1

    Ratio of the reconstructed mass, computed as the most probable value of a fit to a Landau distribution convolved with...

  • Table 2

    Data from Figure 2

    10.17182/hepdata.68640.v1/t2

    Efficiency for the calorimetric MET>80 GeV trigger as a function of the stable R-hadron mass.

  • Table 3

    Data from Figure 2

    10.17182/hepdata.68640.v1/t3

    Efficiency for the calorimetric MET>80 GeV trigger as a function of the metastable R-hadron mass. The R-hadron decays to g/qq...

  • Table 4

    Data from Figure 2

    10.17182/hepdata.68640.v1/t4

    Efficiency for the calorimetric MET>80 GeV trigger as a function of the metastable R-hadron mass. The R-hadron decays to g/qq...

  • Table 5

    Data from Figure 2

    10.17182/hepdata.68640.v1/t5

    Efficiency for the calorimetric MET>80 GeV trigger as a function of the metastable R-hadron mass. The R-hadron decays to g/qq...

  • Table 6

    Data from Figure 2

    10.17182/hepdata.68640.v1/t6

    Efficiency for the calorimetric MET>80 GeV trigger as a function of the stable chargino mass.

  • Table 7

    Data from Figure 3

    10.17182/hepdata.68640.v1/t7

    Total selection efficiency as a function of the stable R-hadron mass.

  • Table 8

    Data from Figure 3

    10.17182/hepdata.68640.v1/t8

    Total selection efficiency as a function of the metastable R-hadron mass. The R-hadron decays to g/qq plus neutralino of mass...

  • Table 9

    Data from Figure 3

    10.17182/hepdata.68640.v1/t9

    Total selection efficiency as a function of the metastable R-hadron mass. The R-hadron decays to g/qq plus neutralino of mass...

  • Table 10

    Data from Figure 3

    10.17182/hepdata.68640.v1/t10

    Total selection efficiency as a function of the metastable R-hadron mass. The R-hadron decays to g/qq plus neutralino of mass...

  • Table 11

    Data from Figure 3

    10.17182/hepdata.68640.v1/t11

    Total selection efficiency as a function of the stable chargino mass.

  • Table 12

    Data from Figure 4

    10.17182/hepdata.68640.v1/t12

    Ionisation distribution of all the CR2 tracks, and those not matched to a reconstructed muon. The two distributions are normalised...

  • Table 13

    Data from Figure 5a

    10.17182/hepdata.68640.v1/t13

    Distribution of the mass of selected candidates, derived from the specific ionisation loss, for an example of gluino R-hadron signal,...

  • Table 14

    Data from Figure 5a

    10.17182/hepdata.68640.v1/t14

    Distribution of the mass of selected candidates, derived from the specific ionisation loss, for one example of chargino signal, for...

  • Table 15

    Data from Figure 5a

    10.17182/hepdata.68640.v1/t15

    Distribution of the mass of selected candidates, derived from the specific ionisation loss, for background and data, for searches for...

  • Table 16

    Data from Figure 5b

    10.17182/hepdata.68640.v1/t16

    Distribution of the mass of selected candidates, derived from the specific ionisation loss, for an example of gluino R-hadron signal,...

  • Table 17

    Data from Figure 5b

    10.17182/hepdata.68640.v1/t17

    Distribution of the mass of selected candidates, derived from the specific ionisation loss, for an example of chargino signal, for...

  • Table 18

    Data from Figure 5b

    10.17182/hepdata.68640.v1/t18

    Distribution of the mass of selected candidates, derived from the specific ionisation loss, for background and data. The expected background...

  • Table 19

    Data from Figure 6a

    10.17182/hepdata.68640.v1/t19

    Theoretical values for the cross section of gluino pairs production with their uncertainty.

  • Table 20

    Data from Figure 6a

    10.17182/hepdata.68640.v1/t20

    Expected upper limits on the production cross section as a function of mass for metastable gluino R-hadrons, with lifetime tau...

  • Table 21

    Data from Figure 6a

    10.17182/hepdata.68640.v1/t21

    Observed 95 PCT upper limits on the production cross section as a function of mass for metastable gluino R-hadrons, with...

  • Table 22

    Data from Figure 6b

    10.17182/hepdata.68640.v1/t22

    Expected upper limits on the production cross section as a function of mass for metastable gluino R-hadrons, with lifetime tau...

  • Table 23

    Data from Figure 6b

    10.17182/hepdata.68640.v1/t23

    Observed 95 PCT upper limits on the production cross section as a function of mass for metastable gluino R-hadrons, with...

  • Table 24

    Data from Figure 7a

    10.17182/hepdata.68640.v1/t24

    The expected excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into g/qq plus a...

  • Table 25

    Data from Figure 7a

    10.17182/hepdata.68640.v1/t25

    The expected excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into g/qq plus a...

  • Table 26

    Data from Figure 7a

    10.17182/hepdata.68640.v1/t26

    The expected excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into g/qq plus a...

  • Table 27

    Data from Figure 7a

    10.17182/hepdata.68640.v1/t27

    The observed excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into g/qq plus a...

  • Table 28

    Data from Figure 7a

    10.17182/hepdata.68640.v1/t28

    The observed excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into g/qq plus a...

  • Table 29

    Data from Figure 7a

    10.17182/hepdata.68640.v1/t29

    The observed excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into g/qq plus a...

  • Table 30

    Data from Figure 7b

    10.17182/hepdata.68640.v1/t30

    The expected excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into g/qq plus a...

  • Table 31

    Data from Figure 7b

    10.17182/hepdata.68640.v1/t31

    The expected excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into g/qq plus a...

  • Table 32

    Data from Figure 7b

    10.17182/hepdata.68640.v1/t32

    The expected excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into g/qq plus a...

  • Table 33

    Data from Figure 7b

    10.17182/hepdata.68640.v1/t33

    The observed excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into g/qq plus a...

  • Table 34

    Data from Figure 7b

    10.17182/hepdata.68640.v1/t34

    The observed excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into g/qq plus a...

  • Table 35

    Data from Figure 7b

    10.17182/hepdata.68640.v1/t35

    The observed excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into g/qq plus a...

  • Table 36

    Data from Figure 8a

    10.17182/hepdata.68640.v1/t36

    Expected upper limits on the production cross section as a function of mass for metastable gluino R-hadrons, with lifetime tau...

  • Table 37

    Data from Figure 8a

    10.17182/hepdata.68640.v1/t37

    Observed 95 PCT upper limits on the production cross section as a function of mass for metastable gluino R-hadrons, with...

  • Table 38

    Data from Figure 8b

    10.17182/hepdata.68640.v1/t38

    Expected upper limits on the production cross section as a function of mass for metastable gluino R-hadrons, with lifetime tau...

  • Table 39

    Data from Figure 8b

    10.17182/hepdata.68640.v1/t39

    Observed 95 PCT upper limits on the production cross section as a function of mass for metastable gluino R-hadrons, with...

  • Table 40

    Data from Figure 9a

    10.17182/hepdata.68640.v1/t40

    The expected excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into tt plus a...

  • Table 41

    Data from Figure 9a

    10.17182/hepdata.68640.v1/t41

    The expected excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into tt plus a...

  • Table 42

    Data from Figure 9a

    10.17182/hepdata.68640.v1/t42

    The expected excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into tt plus a...

  • Table 43

    Data from Figure 9a

    10.17182/hepdata.68640.v1/t43

    The observed excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into tt plus a...

  • Table 44

    Data from Figure 9a

    10.17182/hepdata.68640.v1/t44

    The observed excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into tt plus a...

  • Table 45

    Data from Figure 9a

    10.17182/hepdata.68640.v1/t45

    The observed excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into tt plus a...

  • Table 46

    Data from Figure 9b

    10.17182/hepdata.68640.v1/t46

    The expected excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into tt plus a...

  • Table 47

    Data from Figure 9b

    10.17182/hepdata.68640.v1/t47

    The expected excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into tt plus a...

  • Table 48

    Data from Figure 9b

    10.17182/hepdata.68640.v1/t48

    The expected excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into tt plus a...

  • Table 49

    Data from Figure 9b

    10.17182/hepdata.68640.v1/t49

    The observed excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into tt plus a...

  • Table 50

    Data from Figure 9b

    10.17182/hepdata.68640.v1/t50

    The observed excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into tt plus a...

  • Table 51

    Data from Figure 9b

    10.17182/hepdata.68640.v1/t51

    The observed excluded range of lifetimes as a function of gluino mass for gluino R-hadrons decaying into tt plus a...

  • Table 52

    Data from Figure 10

    10.17182/hepdata.68640.v1/t52

    Theoretical values for the production cross section of charginos or chargino/neutralino pairs, with their uncertainty.

  • Table 53

    Data from Figure 10

    10.17182/hepdata.68640.v1/t53

    Expected upper limits on the production cross section as a function of mass for metastable charginos, with lifetime tau =1.0...

  • Table 54

    Data from Figure 10

    10.17182/hepdata.68640.v1/t54

    Observed 95 PCT upper limits on the production cross section as a function of mass for metastable charginos, with lifetime...

  • Table 55

    Data from Figure 11

    10.17182/hepdata.68640.v1/t55

    The expected excluded range of lifetimes as a function of chargino mass for charginos decaying into neutralino plus pion, with...

  • Table 56

    Data from Figure 11

    10.17182/hepdata.68640.v1/t56

    The expected excluded range of lifetimes as a function of chargino mass for charginos decaying into neutralino plus pion, with...

  • Table 57

    Data from Figure 11

    10.17182/hepdata.68640.v1/t57

    The expected excluded range of lifetimes as a function of chargino mass for charginos decaying into neutralino plus pion, with...

  • Table 58

    Data from Figure 11

    10.17182/hepdata.68640.v1/t58

    The observed excluded range of lifetimes as a function of chargino mass for charginos decaying into neutralino plus pion, with...

  • Table 59

    Data from Figure 11

    10.17182/hepdata.68640.v1/t59

    The observed excluded range of lifetimes as a function of chargino mass for charginos decaying into neutralino plus pion, with...

  • Table 60

    Data from Figure 11

    10.17182/hepdata.68640.v1/t60

    The observed excluded range of lifetimes as a function of gluino mass for chargino mass for charginos decaying into neutralino...

  • Table 61

    Data from Auxiliary Figure 12

    10.17182/hepdata.68640.v1/t61

    dEdx ionization for data, 1 TeV gluino R-hadrons stable and decaying in 100 GeV neutralinos with a 10 ns lifetime...

  • Table 62

    Data from Auxiliary Figure 13

    10.17182/hepdata.68640.v1/t62

    Expected upper limits on the production cross section as a function of mass for stable gluino R-hadrons, in case of...

  • Table 63

    Data from Auxiliary Figure 13

    10.17182/hepdata.68640.v1/t63

    Observed 95 PCT upper limits on the production cross section as a function of mass for stable gluino R-hadrons.

  • Table 64

    Data from Auxiliary Figure 14

    10.17182/hepdata.68640.v1/t64

    Theoretical values for the cross section of squark pairs production with their uncertainty.

  • Table 65

    Data from Auxiliary Figure 14

    10.17182/hepdata.68640.v1/t65

    Expected upper limits on the production cross section as a function of mass for stable sbottom R-hadrons, in case of...

  • Table 66

    Data from Auxiliary Figure 14

    10.17182/hepdata.68640.v1/t66

    Observed 95 PCT upper limits on the production cross section as a function of mass for stable sbottom $R$-hadrons. Cross...

  • Table 67

    Data from Auxiliary Figure 15

    10.17182/hepdata.68640.v1/t67

    Expected upper limits on the production cross section as a function of mass for stop R-hadrons, in case of background...

  • Table 68

    Data from Auxiliary Figure 15

    10.17182/hepdata.68640.v1/t68

    Observed 95 PCT upper limits on the production cross section as a function of mass for stop R-hadrons.

  • Table 69

    Data from Auxiliary Figure 16

    10.17182/hepdata.68640.v1/t69

    Expected upper limits on the production cross section as a function of mass for stable charginos, in case of background...

  • Table 70

    Data from Auxiliary Figure 16

    10.17182/hepdata.68640.v1/t70

    Observed 95 PCT upper limits on the production cross section as a function of mass for stable charginos.

  • Table 71

    Data from Auxiliary Figure 17a

    10.17182/hepdata.68640.v1/t71

    Expected upper limits on the production cross section as a function of mass for metastable gluino R-hadrons, with lifetime tau=1.0...

  • Table 72

    Data from Auxiliary Figure 17a

    10.17182/hepdata.68640.v1/t72

    Observed 95 PCT upper limits on the production cross section as a function of mass for metastable gluino R-hadrons, with...

  • Table 73

    Data from Auxiliary Figure 17b

    10.17182/hepdata.68640.v1/t73

    Expected upper limits on the production cross section as a function of mass for metastable gluino R-hadrons, with lifetime tau=1.0...

  • Table 74

    Data from Auxiliary Figure 17b

    10.17182/hepdata.68640.v1/t74

    Observed 95 PCT upper limits on the production cross section as a function of mass for metastable gluino R-hadrons, with...

  • Table 75

    Data from Auxiliary Figure 18a

    10.17182/hepdata.68640.v1/t75

    Expected upper limits on the production cross section as a function of mass for metastable gluino R-hadrons, with lifetime tau=1.0...

  • Table 76

    Data from Auxiliary Figure 18a

    10.17182/hepdata.68640.v1/t76

    Observed 95 PCT upper limits on the production cross section as a function of mass for metastable gluino R-hadrons, with...

  • Table 77

    Data from Auxiliary Figure 18b

    10.17182/hepdata.68640.v1/t77

    Expected upper limits on the production cross section as a function of mass for metastable gluino R-hadrons, with lifetime tau=1.0...

  • Table 78

    Data from Auxiliary Figure 18b

    10.17182/hepdata.68640.v1/t78

    Observed 95 PCT upper limits on the production cross section as a function of mass for metastable gluino R-hadrons, with...

  • Table 79

    Data from Auxiliary Figure 19

    10.17182/hepdata.68640.v1/t79

    Expected upper limits on the production cross section as a function of mass for metastable charginos, with lifetime tau =15...

  • Table 80

    Data from Auxiliary Figure 19

    10.17182/hepdata.68640.v1/t80

    Observed 95 PCT upper limits on the production cross section as a function of mass for metastable charginos, with lifetime...

Loading Data...