Sneutrino dark matter and its LHC phenomenology

Transcription

1 Sneutrino dark matter and its LHC phenomenology Chiara Arina Physics challenges in the face of LHC-14 IFT 1 September 23 th 2014 Bolshoi simulation, NASA

2 Sneutrino dark matter in the MSSM? Left-handed sneutrino as dark matter: Ibanez 84, Falk et al 94. Sneutrino belongs to the SU(2)L doublet, it has Y=1 and couples to the Z boson 2

3 Sneutrino dark matter in the MSSM? Left-handed sneutrino as dark matter: Ibanez 84, Falk et al 94. Sneutrino belongs to the SU(2)L doublet, it has Y=1 and couples to the Z boson 2

4 Sneutrino dark matter in the MSSM? Left-handed sneutrino as dark matter: Ibanez 84, Falk et al 94. Sneutrino belongs to the SU(2)L doublet, it has Y=1 and couples to the Z boson 2

5 Sneutrino dark matter in the MSSM? Left-handed sneutrino as dark matter: Ibanez 84, Falk et al 94. Sneutrino belongs to the SU(2)L doublet, it has Y=1 and couples to the Z boson 2

6 Sneutrino can not be DM in the MSSM WMAP range EXCLUDED Z-width bound CDMS 3

7 Sneutrino can not be DM in the MSSM WMAP range EXCLUDED Z-width bound CDMS 3

8 Sneutrino can not be DM in the MSSM WMAP range EXCLUDED Z-width bound CDMS 3

9 Are the Dark Matter and the Neutrino sector related? Within SUSY, all mechanisms giving mass to neutrinos (Dirac masses or seesaw type I, II, III, inverse seesaw...) modify the scalar sector as well With modified scalar sector, sneutrino DM is OK Sneutrino DM and neutrino masses are naturally related 4

10 MSSM + inverse seesaw CA,F.Bazzocchi, N.Fornengo, J.Romao and J.Valle, PRL V. De Romeri and M.Hirsch, JHEP

11 MSSM + inverse seesaw CA,F.Bazzocchi, N.Fornengo, J.Romao and J.Valle, PRL V. De Romeri and M.Hirsch, JHEP 2012 = 0 L is conserved 5

12 MSSM + inverse seesaw CA,F.Bazzocchi, N.Fornengo, J.Romao and J.Valle, PRL V. De Romeri and M.Hirsch, JHEP 2012 Neutrino sector = 0 L is conserved Inverse see-saw mechanism m D = v 2 Y m µ S m 2 D M 2 The smallness of the neutrino mass is given by the smallness of 0(keV) 5

13 MSSM + inverse seesaw CA,F.Bazzocchi, N.Fornengo, J.Romao and J.Valle, PRL V. De Romeri and M.Hirsch, JHEP 2012 Neutrino sector = 0 L is conserved Inverse see-saw mechanism m D = v 2 Y m µ S m 2 D M 2 The smallness of the neutrino mass is given by the smallness of 0(keV) Sneutrino sector mixed state of the left-handed sneutrino, the right-handed sneutrino and the singlet scalar field sizeable mixing because all soft masses at the same scale Effect of mixing: (i) coupling with Z boson reduced by the mixing angle (ii) suppressed cross-section for scattering off nucleus 5

14 MSSM + inverse seesaw CA,F.Bazzocchi, N.Fornengo, J.Romao and J.Valle, PRL V. De Romeri and M.Hirsch, JHEP 2012 Neutrino sector = 0 L is conserved Inverse see-saw mechanism m D = v 2 Y m µ S m 2 D M 2 The smallness of the neutrino mass is given by the smallness of 0(keV) Sneutrino sector mixed state of the left-handed sneutrino, the right-handed sneutrino and the singlet scalar field sizeable mixing because all soft masses at the same scale Effect of mixing: (i) coupling with Z boson reduced by the mixing angle (ii) suppressed cross-section for scattering off nucleus 5

15 SUSY mass spectrum with sneutrino LSP LHC are different from MSSM 6

16 Signatures in the simplest scenario: MSSM+RN Arkani-Hamed et al. 00, CA and N.Fornengo 07, G.Belanger et al. 10, 12 CA and M.E.Cabrera JHEP 04(2104)100 Dirac masses for neutrinos: Sneutrino left and right component mixes: 7

17 Signatures in the simplest scenario: MSSM+RN Arkani-Hamed et al. 00, CA and N.Fornengo 07, G.Belanger et al. 10, 12 CA and M.E.Cabrera JHEP 04(2104)100 Dirac masses for neutrinos: Sneutrino left and right component mixes: LSP 7

18 Free parameters and likelihood constraints 13 free parameters (GUT scale initial conditions) Observable with a measure have a gaussian likelihood: 1. Higgs mass 2. from Planck 3. Z invisible decay width Constraints that have only an lower/upper limits are included with a step likelihood function: 1. Chargino and slepton masses > 101 GeV (95% CL LEP) 2. Stau > 85 GeV (95% CL LEP) 3. LUX bound at 90% CL 4. Higgs invisible decay width (< 60%) Sampling of the likelihood with the algorithm MultiNest 8

19 Sneutrino is a good dark matter candidate LUX XENON1T 9

20 Because of LUX the LSP is mostly right-handed Different colors characterized by a different mass spectrum pattern and different annihilation processes that fix the relic density 10

21 What is the current status of MSSM+RN with respect to LHC searches? 11

22 What is the current status of MSSM+RN with respect to LHC searches? 11

23 Test electroweak production in the MSSM+RN Work in progress in collaboration with CA, M.E.Cabrera, S.Kraml, S.Kulkarni and U.Laa Notice that the points below are not excluded, except for almost pure wino charginos! 12

24 Test electroweak production in the MSSM+RN Work in progress in collaboration with CA, M.E.Cabrera, S.Kraml, S.Kulkarni and U.Laa Notice that the points below are not excluded, except for almost pure wino charginos! 12

25 Test electroweak production in the MSSM+RN Work in progress in collaboration with CA, M.E.Cabrera, S.Kraml, S.Kulkarni and U.Laa Notice that the points below are not excluded, except for almost pure wino charginos! 12

26 Test electroweak production in the MSSM+RN 13

27 Test electroweak production in the MSSM+RN 13

28 Why slepton production relevant? p MSSM Chargino production l 01 p MSSM+RN Chargino production l χ 1 ν l 1 W χ 1 ν l 1 χ + 1 W + ν l 1 χ + 1 ν l 1 p l + 01 Slepton production p Slepton production W l + l+ 01 l l 1 l 01 l+ l + W + The scalar nature of the sneutrino has the effect of exchange the final state for slepton production with the one for electroweak production of the MSSM! 14

29 Test electroweak production in the MSSM+RN (most recurrent ones) 15

30 Test electroweak production in the MSSM+RN (most recurrent ones) Real model that produces mono-leptons! large cross-section! 15

31 Test electroweak production in the MSSM+RN (most recurrent ones) Real model that produces mono-leptons! large cross-section! 15

32 Future predictions: Green points (Higgs pole) pattern Mass spectrum CA and M.E.Cabrera, JHEP 04(2104)100 Relic density is set by Via s-channel Higgs exchange by definition of Higgs pole 16

33 Future predictions: Green points (Higgs pole) pattern Mass spectrum CA and M.E.Cabrera, JHEP 04(2104)100 Relic density is set by Via s-channel Higgs exchange by definition of Higgs pole 16

34 Future predictions: Green points (Higgs pole) pattern Mass spectrum CA and M.E.Cabrera, JHEP 04(2104)100 Relic density is set by Via s-channel Higgs exchange by definition of Higgs pole 16

35 3 uncorrelated leptons l + ν l τ ± ν l ν l τ ± ν l 2 χ 0 1 W ν l 2 χ 0 1 W χ + 1 τ 1 χ 0 2 τ 1 ν τ ν τ Feature characteristic of the Higgs pole (LSP very right-handed) Sleptons are lighter than charginos and neutralinos (typically stau is the NLSP) The two final taus are not tagged due to low efficiency 17

36 3 uncorrelated leptons l + ν l τ ± ν l ν l τ ± ν l 2 χ 0 1 W ν l 2 χ 0 1 W χ + 1 τ 1 χ 0 2 τ 1 ν τ ν τ Feature characteristic of the Higgs pole (LSP very right-handed) Sleptons are lighter than charginos and neutralinos (typically stau is the NLSP) The two final taus are not tagged due to low efficiency 17

37 3 uncorrelated leptons number of events / 50 GeV ± W ± 1 Z ± t t W L = 100/fb p miss T [GeV] number of events / 50 GeV ± W ± 1 Z ± t t W L = 100/fb Additional cut forbidding OSSF leptons p miss T [GeV] 18

38 Conclusions and work in progress Dark matter in connection with neutrino masses can provide signatures into leptons which are different from the standard MSSM Study of kinematics proper to sneutrinos for SModelS Application of SModelS to light squark sector as well Complementarity of searches among LHC and XENON1T What about seesaw models? 19

39 Backup slides Predictions for LHC from sneutrino dark matter 20

40 Test electroweak production in the MSSM+RN 21

41 Set up of the analysis FeynRules WIMP Model = MSSM+RN Supersymmetric mass spectrum SoftSUSY Relic Abundance + dark matter direct detection predictions micromegas Predictions at LHC MadGraph5, Pythia, Delphes 22

42 Orange points pattern Mass spectrum Relic density is set by Very subdominant unless >

43 Orange points pattern Mass spectrum Relic density is set by Very subdominant unless >

44 Orange points pattern Mass spectrum Relic density is set by Very subdominant unless >

45 Long-lived staus Signature arising when: 1. Stau is the NSLP 2. small MSSM + RN MSSM 24 Existing bound: massllp > 300 GeV allowed (ATLAS-CONF )

46 Long-lived staus Staus produced in pair directly Assumed observation of both charged tracks from the hadronic calorimeter to escaping charged particles (ATLAS efficiency ) 25

47 Long-lived staus Staus produced in pair directly Assumed observation of both charged tracks from the hadronic calorimeter to escaping charged particles (ATLAS efficiency ) 25

48 Magenta points pattern Mass spectrum Relic density is set by sneutrino and coannihilation/annihilation with the lightest neutralino Blue points have chargino degenerate as well, relic density set by neutralino/gaugino sectors and LSP very sterile: hard to distinguish from MSSM 26

49 Magenta points pattern Mass spectrum Relic density is set by sneutrino and coannihilation/annihilation with the lightest neutralino Blue points have chargino degenerate as well, relic density set by neutralino/gaugino sectors and LSP very sterile: hard to distinguish from MSSM 26

50 Magenta points pattern Mass spectrum Relic density is set by sneutrino and coannihilation/annihilation with the lightest neutralino Blue points have chargino degenerate as well, relic density set by neutralino/gaugino sectors and LSP very sterile: hard to distinguish from MSSM 26

51 Chargino production p l χ 1 χ + 1 ν l 1 ν l 1 When chargino is ligther than sleptons Decay 2-body into the LSP (MSSM is 3-body) p l + 27

52 Chargino production p l χ 1 χ + 1 ν l 1 ν l 1 When chargino is ligther than sleptons Decay 2-body into the LSP (MSSM is 3-body) p l + Signal: 2 leptons with opposite sign and uncorrelated flavor 27

53 Chargino production `Transverse-mass (from A.Barr,C.Lester,P.Stephens 03) L = 100/fb number of events / 50 GeV W W ± W Z L = 100/fb S / B / 100 GeV M T2 [GeV] M T2 [GeV] 28

54 Chargino production `Transverse-mass (from A.Barr,C.Lester,P.Stephens 03) L Signal = 100/fb number of events / 50 GeV L = 100/fb W W ± W Z L = 100/fb S / B / 100 GeV M T2 T2 [GeV] [GeV] M T2 [GeV] 28

55 Chargino production Effective transverse energy (from M.E.Cabrera, A.Casas 12) invariant mass of the pair of leptons transverse momentum of the pair of leptons L = 100/fb number of events / 100 GeV W W ± W Z L = 100/fb S / B / 200 GeV eff E T [GeV] eff E T [GeV] 29

56 Chargino production Effective transverse energy (from M.E.Cabrera, A.Casas 12) invariant mass of the pair of leptons transverse momentum of the pair of leptons Signal L = 100/fb number of events / 100 GeV number of events / 100 GeV L = 100/fb W W ± W Z L = 100/fb S / B / 200 GeV eff eff E E T T [GeV] [GeV] eff E T [GeV] 29

57 Gray points pattern Mass spectrum Relic density is set by sneutrino itself Via s-channel Z exchange or t-channel neutralino exchange 30

58 Gray points pattern Mass spectrum Relic density is set by sneutrino itself Via s-channel Z exchange or t-channel neutralino exchange 30

59 Gray points pattern Mass spectrum Relic density is set by sneutrino itself Via s-channel Z exchange or t-channel neutralino exchange 30

60 2 Same sign leptons, uncorrelated flavor τ W ± p χ 0 j τ ± 1 Arises when the stau is the NLSP p χ + i τ + 1 ν τ 1 ν τ 1 Different from MSSM where the OS leptons should have the same flavor ν τ W + 31

61 2 Same sign leptons, uncorrelated flavor τ W ± p χ 0 j τ ± 1 Arises when the stau is the NLSP p χ + i τ + 1 ν τ 1 ν τ 1 Different from MSSM where the OS leptons should have the same flavor ν τ W + 31

62 2 Same sign leptons, uncorrelated flavor number of events / 50 GeV ± W ± 1 Z ± t t W L = 100/fb number of events / 50 GeV 10 1 L = 100/fb M inv [GeV] M inv [GeV] The signal is hidden at low pt and Minv values, where the background is maximal 32

63 2 Same sign leptons, uncorrelated flavor number of events / 50 GeV ± W ± 1 Z ± t t W L = 100/fb number of events / 50 GeV 10 1 L = 100/fb p miss T [GeV] p miss T [GeV] The signal is hidden at low pt and Minv values, where the background is maximal 33