Two-pixel-hitsearchesforwinoandhiggsino

NatsumiNagataUniversityofTokyo

DarkSideoftheUniverse2017Jul.13,2017

KAISTMunjiCampus,Daejeon,Korea

BasedonH.Fukuda,N.Nagata,H.Otono,andS.Shirai,arXiv:1703.09675.

Begemanet.al.(1991)

Cloweet.al.(2006)2 10 500

1000

2000

3000

4000

5000

6000

D[µK

2 ]

90 18

500 1000 1500 2000 2500

Multipole moment,

1 0.2 0.1 0.07Angular scale

Planck(2013)

EvidenceforDM

Weakly-InteracYngMassiveParYcles(WIMPs)• NeutralandstableparYcleswithEW-scalemasses.• Weakly-interacYngwithordinaryma\ers.

ThermalrelicabundanceagreeswiththeobservedDMdensity.

DarkMa8er(DM)

Supersymmetry(SUSY)SUSYisthemostpromisingcandidateforphysicsbeyondtheSM.

CurrentconstraintsonSUSY

• NullresultsforSUSYsearches

• 125GeVHiggsmass

SUSYscalemaybemuchhigherthantheEWscale.

IsthereanygoodWIMPdarkma\ercandidateeveninahigh-scaleSUSYmodel?

Canweprobesuchadarkma\erparYcle??

Focus-point,coannihilaYonregion,electroweakino,…

Supersymmetry(SUSY)SUSYisthemostpromisingcandidateforphysicsbeyondtheSM.

CurrentconstraintsonSUSY

• NullresultsforSUSYsearches

• 125GeVHiggsmass

SUSYscalemaybemuchhigherthantheEWscale.

IsthereanygoodWIMPdarkma\ercandidateeveninahigh-scaleSUSYmodel?

Canweprobesuchadarkma\erparYcle??

Focus-point,coannihilaYonregion,electroweakino,…

SeetalksbyJasonL.Evans,JunichiroKawamura,SengPeiLiew,…

High-scaleSUSYL.J.Hall,Y.Nomura,S.Shirai(2012)

M.Ibe,S.Matsumoto,T.T.Yanagida(2012)A.Arvanitaki,N.Craig,S.Dimopoulos,G.Villadoro(2012)

N.Arkani-Hamed,A.Gupta,D.E.Kaplan,N.Weiner,andT.Zorawski(2012)

IftheKahlerpotenYalhasagenericformandthereisnosingletfieldintheSUSYbreakingsector;

Gravi!no Scalar Par!cles Higgsinos

Gauginos

O(10 ) TeV

O(1) TeV

Gluino

Bino

Wino

(2-5)

125GeVHiggsmassisrealized.

GauginomassesareinducedbyanomalymediaYon.L.RandallandR.Sundrum(1998)

G.F.Giudice,M.A.Luty,H.Murayama,andR.Ra\azzi(1998)

• Wino(3TeV)• Higgsino(1TeV)

Thiscanbelight.

DMcandidates:

CanweprobethemattheLHC??

MassspliBng

ψm ψm+1,m−1

W

ψm ψm ψmψm

Z, γ

Charged-neutralmassspliingisgeneratedviaIRradiaYvecorrecYonsbyEWgaugebosonloops.

Non-decouplingeffect

O(100)MeV.H

eavy

win

o lim

itby

Yam

ada

(200

9)

150

155

160

165

170

100 1000

δm [M

eV]

mneutralino [GeV]

Hea

vy w

ino

limit

by Y

amad

a (2

009)

two-loopone-loop

M.Ibe,S.Matsumoto,R.Sato(2012).

Two-loopcalculaYon(wino,Y=0)

LHCsearch

HardtoprobethemattheLHC??

χ±

χ0

π±

TheproducYoncrosssecYonsoftheseparYclestendtobemuchsmallerthanthoseofcoloredparYcles.

Moreover,sincethemassdifferencesamongthecomponentsarefairlysmall,momentaofdecayproductsareverysoo.

SeealsotalkbyShoaibMunir.

WinolifeFmeDuetothesmallmassspliing,winobecomesratherlong-lived.

Maindecaychannel:

BranchingfracYonfortheleptonicdecaymodes(three-bodydecay)isafew%.

0

5

10

15

100 150 200 250 0

0.1

0.2

0.3

0.4

0.5

c τ [

cm]

τ [ns

]

mchargino [GeV]

two-loopone-loop

Decaywithinadetector!M.Ibe,S.Matsumoto,R.Sato(2012).

DisappearingtracksearchesAchargedwinowithadecaylengthofO(1)cmleavesadisappearingtrackindetectors.

ChargedtrackETmiss Toosootobedetected

J.L.Feng,T.Moroi,L.Randall,M.Strassler,S.F.Su(1999);M.Ibe,T.Moroi,T.T.Yanagida(2006),etc…

ATLAS Simulation Preliminary

π+

χ01

~ χ+1

~

Requiringthissignature,wecanreduceSMBGsignificantly.

Signaltopology

χ±1p

p

χ01

χ01

π±

j IniYalStateRadiaYon(ISR)

LargeETmiss

SinglejetDisappearingtrack

RoleofISR

• Trigger• Boostthesystem

ImprovementfromRun-1@ATLASATLASinnerdetector

New!!

InsertableB-layer(IBL)

Requirementfordisappearingtracks

Run-1:3pixel+1SCThitsRun-2:4pixelhits

30cm→12cm

[GeV]1±χ∼

m100 200 300 400 500 600 700

[ns]

1±χ∼τ

0.01

0.020.030.04

0.1

0.20.30.4

1

234

10

)theoryσ1 ±Observed 95% CL limit ( )expσ1 ±Expected 95% CL limit (

, EW prod.)-1ATLAS (8 TeV, 20.3 fbTheory (Phys. Lett. B721 252 (2013))ALEPH (Phys. Lett. B533 223 (2002))

ATLAS Preliminary-1=13TeV, 36.1 fbs

> 0µ = 5, βtan

Results

ATLAS-CONF-2017-017Winowithamassupto430GeVhasbeenexcluded!

BG:\bar,W+jets

Pixel

SCT

Pixel

SCT

Pixel

SCT

Hadronicsca\ering Bremsstrahlung Twonearbytracks(fake)

ShorterdisappearingtracksIfrequirednumberofhitsisreduced,thenthesignaleventsaremuchenhanced.

IBL

3 cm

5 cm

9 cm

12 cm

30 cm

37 cm

44 cm

51 cm

56 cm

Pixel

SCT

Pixel

TRT

Primary vertex

Run 1 Run 2

Proposal

Wemayusetheprimaryvertextogetherwithtwopixellayers!

ButmomentumresoluYonbecomesverypoor….

NeedtoconsiderfurtherstrategiestoreduceBGevents.

BackgroundreducFon• UsedisplacedverYcesBGeventstendtobeassociatedwithtrackswithalargeimpactparameter.

DVreconstrucYontechniquemaybeusedtoeliminatethem.

• Useanomalouslylargeenergydeposit

BeingdevelopedbyATLASpeople

• Smallersizepixeltrackers??Consideredseriously[1511.02080].

Two-hitstrategyLetusbeopYmisYc.SupposewecanreduceBGsufficiently.

1

10

100

500 1000 1500 2000 2500 3000 3500

c[cm

]

wino mass [GeV]

Run

1R

un2

(13

TeV

, 36

fb1 )

Two

Hits

(14

TeV

3ab

1 )

Tw

oH

its

(33

TeV

3ab

1 )

c(pure wino) Therm

alrelic

#ofBGevents:0—10

5cm

3cm

ETmiss,PTlead>400GeVfor14TeV.

ETmiss,PTlead>600GeVfor33TeV.

Wemayprobewholeregionwitha33TeVcollider!

Expectedlimits

BasedonH.Fukuda,N.Nagata,H.Otono,andS.Shirai[arXiv:1703.09675].

1TeVwinoiswithinthereachoftheLHC.

AlmostPureHiggsinoarg(M

2)

[deg

]

|M2| [GeV]

Mass MeasurementInelastic Dark Matter

Elastic Dark MatterEDM

0

50

100

150

200

250

300

350

103 104 105 106 107 108

N.NagataandS.Shirai,JHEP1501,029(2015).

Higgsmass→tanβA-terms:0

Parameters

Futureprospects

This“almostpureHiggsino”DMregionishardtoprobe.

PureHiggsinoCharged-neutralmassdifference

Tooshorttobeprobedsofar…

0

50

100

150

200

250

300

350

103 104 105 106

arg(M

2)

[deg]

|M2| [GeV]

m±1m1[GeV]

without resum

1 0.7 0.4 0.34

Contrarytothewinocase,itisdifficulttosearchforapureHiggsinowithconvenYonaldisappearingtracksearches.

0.60.8

11.21.4

103 104 105 106

resu

m/t

ree

|M2| [GeV]

1049

1048

1047

1046

1045

1044

SIcr

oss

sect

ionp SI

[cm

2] 2 = 0

90180

LUX exclusionNeutrino BG

Figure 8: SI scattering cross sections of the Higgsino DM with a proton as functions of |M2| in solidlines. Here we take tan = 2, µ = 500 GeV, M1 = M2 and em = |M2|. Red-solid, green-dashed, andblue short-dashed lines correspond to 2 = arg(M2) = 0, /2 and , respectively. Upper blue-shadedregion is excluded by the LUX experiment [61]. Lower gray-shaded region represents the limitationof the direct detection experiments due to the neutrino background [69]. Lower panel represents thee↵ects of the resummation on the calculation.

5 Electric Dipole Moments

Generally, the MSSM induces new sources of CP violations, which may lead to large electric dipole

moments (EDMs) of the SM fermions. One of the important contributions comes from one-loop

diagrams which includes SUSY scalar particles. Another significant contribution is two-loop dia-

grams without the SUSY scalar particles. In the present “lonely Higgsino” scenario (typically when

em 10 TeV), the latter contribution is dominant.

As we noted above, the mass di↵erence between the neutral components depends on the new

CP phases in the e↵ective interactions in Eqs. (4) and (8), and their e↵ects can be probed with the

EDMs. The dominant contribution to the EDMs comes from the two-loop Barr-Zee diagrams [70]

shown in Fig. 9 [71–73]. To evaluate the contribution, let us first show the Higgs-charged Higgsino

vertex:

Lint = Re(d2)vh eH+ eH+ + Im(d2)vh eH+i5 eH+ , (52)

and the CP-odd part (the second term) is relevant to our calculation.

The definition of the EDMs of fermion f is

LEDM = i

2dff

µ5Fµf . (53)

15

Two-hitstrategyforHiggsino

0.1

1

10

100

200 400 600 800 1000 1200 1400

c[c

m]

Higgsino mass [GeV]

Run

1

Run2 (13

TeV

36fb1 )

Two Hits (14TeV 3 ab

1 )

Two Hits (33 TeV 3 ab1 )

c(pure Higgsino)mtree = +75 MeV

Therm

alrelic

+150 MeV

#ofBGevents:0—10

ETmiss,PTlead>400GeVfor14TeV.

ETmiss,PTlead>600GeVfor33TeV.

H.Fukuda,N.Nagata,H.Otono,andS.Shirai,arXiv:1703.09675.

Again,wholeregioncanbecoveredwitha33TeVcollider!

Withthetwo-hitstrategy,evenpureHiggsinomaybeprobed.

ConclusionInhigh-scaleSUSYscenarios,winoorhiggsinoisagoodDMcandidate.

Thecharged-neutralmassspliingoftheseparYclesisinducedatlooplevel.

Becauseofthesmallmassdifference,theseparYcleshaveadecaylengthofO(1)cm,whichallowsustoprobethemwithdisappearingtracksearches.

Disappearingtracksearcheswithtwopixelhitsareverypromising.

Wino(higgsino)withamassof1.2TeV(500GeV)canbeprobedattheLHC.

Backup

Sommerfeldeffects

0

0.1

0.2

0.3

1 2 3m (TeV)

Non−perturbativePerturbative

WMAP

Wino

SommerfeldeffectsignificantlyenhancesannihilaYoncrosssecYons.

J.Hisano,et.al.,(2006). M.Cirelli,et.al.,(2007).

Aheaviermassisfavoredintermsofthermalrelic.

InordertomakeaprecisepredicYonfortheDMmass,weneedtotakethiseffectintoaccount.

Higgsino

0 0.2 0.4 0.6 0.8 1 1.2 1.4DM mass in TeV

0

0.05

0.1

0.15

0.2

ΩDMh2

Fermion doublet with |Y | = 1/2 (‘higgsino’)

8TeVresults

[GeV]1±χ∼

m100 150 200 250 300 350 400 450 500 550 600

[MeV

]1χ∼

m∆

140

150

160

170

180

190

200

210

220

ATLAS-1 L dt = 20.3 fb∫ = 8 TeV, s

)theoryσ1 ±Observed 95% CL limit ()expσ1 ±Expected 95% CL limit (

, EW prod.)-1 = 7 TeV, 4.7 fbsATLAS (ALEPH (Phys. Lett. B533 223 (2002))Theory (Phys. Lett. B721 252 (2013))

±

1χ∼‘Stable’

> 0µ = 5, βtan

ATLAS CMS

[GeV]1±χ∼

m100 200 300 400 500 600

[MeV

]1χ∼

m∆

140

150

160

170

180

190

200

210

220

σ2 ±Expected limit

σ1 ±Expected limit

Expected limit

Observed limitTheory (Phys. Lett. B721 (2013) 252)

forbidden±π 0χ∼ → ±χ∼

(8 TeV)-119.5 fb

CMS > 0µ = 5, βtanσ2 ±Expected limit

σ1 ±Expected limit

Expected limit

Observed limitTheory (Phys. Lett. B721 (2013) 252)

forbidden±π 0χ∼ → ±χ∼

Awinowithamassof<270(260)GeVwasexcludedbytheATLAS(CMS)8TeVresult.

ReconstrucFonefficiency

Decay radius [mm]0 200 400 600 800 1000

Rec

onst

ruct

ion

effic

ienc

y

0

0.2

0.4

0.6

0.8

1

= 0.2 ns)±

1χ∼τ= 400 GeV, ±

1χ∼

m(EW prod., Fraction of chargino decays

] -1

Frac

tion

of c

harg

ino

deca

ys [

mm

00.20.40.60.811.21.4

1.61.82

Pixel trackletsStandard tracks

ATLAS Simulation Preliminary

-310×

Pixel SCT TRT

Require7hitsinthesilicondetector

ReconstrucYonefficiencybeforeapplyingthefake-rejecYoncriteria

NohitinSCTisrequired.

ForcharginoswithalifeYmeof0.2ns,thereconstrucYonefficiencyusingpixeltrackletsis5—10%.

ATLAS-CONF-2017-017

EventselecFoncriteriaSelecYonfordisappearingtracks

• pT>20GeV• ΔR>0.4foranyjets(pT>50GeV)• ΔR>0.4formuonspectrometertrack(pT>10GeV)• pTcone40/pT<0.04

IsolaYonandpT

Quality• 4hitsinthepixeldetector• |d0|/σ(d0)<2.0• |z0sinθ|<0.5mm• χ2-probabilityoftrackfit>10%

Geometricalacceptance

• 0.1<|η|<1.9DisappearingcondiYon

• NohitintheSCT ATLAS-CONF-2017-017

Reducefaketracks

90%

65—70%

85—90%

75—85%

SignalefficiencyforawinowithalifeYmeof0.2ns

AoeralltheselecYoncuts,thesignalefficiencyis4%fora400GeVwinowithalifeYmeof2ns.

EventselecFoncriteriaKinemaYcalselecYon

• Leptonveto• ETmiss>140GeV• Δφ(Jet1,2,3,4,)>1.0

40% (400GeVwinowithalifeYmeof0.2ns)

ATLAS-CONF-2017-017

BackgroundBGeventsmainlycomefrom\bar,W+jets(W→eν,τν)

Pixel

SCT

Pixel

SCT

Pixel

SCT

Hadronicsca\ering Bremsstrahlung(leptons) Twonearbytracks(fake)

FitdatawithpTshapesofBG+signalcomponentswithanunbinnedlikelihoodfuncYon.

NeedpTdistribuYonsofeachcomponent.

]-1 [TeV Tp/q ∆

100− 50− 0 50 100

Arbi

trary

Uni

ts

5−10

4−10

3−10

2−10

1−10ATLAS Preliminary

-1=13TeV, 36.1 fbs

DataFit function

BackgroundesFmaFonToesYmateBG,weneedtoobtainpTdistribuYonofpixel-onlytracks.

pTdistribuYonofstandardtracks

Smearing(obtainedfromZ→μμ)

pTdistribuYonofpixel-onlytracks

t [GeV]P

Arbi

trary

Uni

ts3−10

2−10

1−10Standard tracksPixel trackletsSmeared tracks

ATLAS Simulation Preliminary

candidatesµµ →Z

[GeV]Tp

10 210 310 410

(Pix

el tr

ackl

ets)

(Sm

eare

d tra

cks)

/

0.00.51.01.52.0

Lookintodifferencebetweenstandardandpixel-onlytracks.

BackgroundesFmaFonHadronbackgroundDeterminethepTdistribuYonshapeinthecontrolregion,andsmearittoobtainthatinthesignalregion.

ThepTdistribuYonofsca\eredhadronsisthesameasthatofnon-sca\eredhadrons(simulaYons).

Arbi

trary

Uni

ts

0.03

0.04

0.05

0.06ATLAS Simulation Preliminary

=13TeVs

[GeV]TpTruth

30 40 50 60 70 80 100

Rat

io

0.80.9

11.11.2

Scattered pionNon-scattered pion

BackgroundesFmaFonLeptonbackgroundUseone-leptonevents.

pTdistribuYonoftheleptoncontrolsample

TransferfactorR(probabilityforaleptontopassthedisappearingtrackselecYon)

SmearpTspectrumbyusingasmearfuncYon

Transferfactor Tag-and-probemethodusingZ→μμ

Tag:well-idenYfiedelectronProbe:energyclusterinthecalorimeterwithanassociatedtracksaYsfyingthequality,isolaYon,pTcriteria.

R=#ofprobesyieldingadisappearingtrack

#oftotalprobesSimilarprocedureformuons.

Trac

klet

s

1−10

1

10

210

310 ATLAS Preliminary-1=13TeV, 36.1 fbs

EW productionFake control region

[GeV]TpTracklet

30 100 200 1000 10000Fit f

unct

ion

Dat

a /

00.5

11.5

2

DataFitfunction

BackgroundesFmaFonFaketracksThesetrackstendtohavealargeimpactparameter.• |d0|/σ(d0)>10• WithoutETmissrequirement

FitthefollowingempiricalfuncYon:

NoETmissdependencewasfound.

Small|d0|/σ(d0)dependenceistakenintoaccountasuncertainty.

ResultsTr

ackl

ets

3−10

2−10

1−101

10

210

310

410Fake trackletMuonHadronElectronSignalTotal Background

DataATLAS Preliminary-1=13TeV, 36.1 fbs

EW productionregionmiss

TEHigh

) = (400 GeV, 0.20 ns)±χ∼τ, ±χ∼m(

[GeV]TpTracklet

30 100 200 1000 10000

Dat

a / B

G

00.5

11.5

2

ATLAS-CONF-2017-017Noexcesshasbeenobserved!

ResultsHigh Emiss

T region Electroweak channel Strong channel(m±

1, ±

1) =(400 GeV, 0.2 ns) (mg, m±

1, ±

1) =(1600 GeV, 500 GeV, 0.2 ns)

Number of observed events with pT > 100 GeV

Observed 9 2Number of expected events with pT > 100 GeV

Hadron+electron background 6.1± 0.6 2.08± 0.35Muon background 0.1549± 0.0022 0.0385± 0.0005Fake background 5.5± 3.3 0.0± 0.8Total background 11.8± 3.1 2.1± 0.9Expected signal 10.4± 1.7 4.1± 0.5CLb 0.39 0.702Observed 95%

vis [fb] 0.22 0.14Expected 95%

vis [fb] 0.24+0.100.07 0.11+0.06

0.04

ATLAS-CONF-2017-017Noexcesshasbeenobserved!

InelasFcsca8eringboundThereisanupperboundonthegauginomassesfromtheinelasYcsca\eringbound.

0.7

0.8

0.9

103 104 105 106 107 108

resu

m/t

ree

|M2| [GeV]

10−5

10−4

10−3

10−2

10−1

100

101

Mas

sD

iffer

ence

∆m

[GeV

]

φ2 = 0

90

Inelastic DM limit

0.60.8

11.21.4

103 104 105 106

resu

m/t

ree

|M2| [GeV]

1049

1048

1047

1046

1045

1044

SIcr

oss

sect

ionp SI

[cm

2] 2 = 0

90180

LUX exclusionNeutrino BG

Figure 8: SI scattering cross sections of the Higgsino DM with a proton as functions of |M2| in solidlines. Here we take tan = 2, µ = 500 GeV, M1 = M2 and em = |M2|. Red-solid, green-dashed, andblue short-dashed lines correspond to 2 = arg(M2) = 0, /2 and , respectively. Upper blue-shadedregion is excluded by the LUX experiment [61]. Lower gray-shaded region represents the limitationof the direct detection experiments due to the neutrino background [69]. Lower panel represents thee↵ects of the resummation on the calculation.

5 Electric Dipole Moments

Generally, the MSSM induces new sources of CP violations, which may lead to large electric dipole

moments (EDMs) of the SM fermions. One of the important contributions comes from one-loop

diagrams which includes SUSY scalar particles. Another significant contribution is two-loop dia-

grams without the SUSY scalar particles. In the present “lonely Higgsino” scenario (typically when

em 10 TeV), the latter contribution is dominant.

As we noted above, the mass di↵erence between the neutral components depends on the new

CP phases in the e↵ective interactions in Eqs. (4) and (8), and their e↵ects can be probed with the

EDMs. The dominant contribution to the EDMs comes from the two-loop Barr-Zee diagrams [70]

shown in Fig. 9 [71–73]. To evaluate the contribution, let us first show the Higgs-charged Higgsino

vertex:

Lint = Re(d2)vh eH+ eH+ + Im(d2)vh eH+i5 eH+ , (52)

and the CP-odd part (the second term) is relevant to our calculation.

The definition of the EDMs of fermion f is

LEDM = i

2dff

µ5Fµf . (53)

15

Gauginomassesshouldbesmallerthan～104TeV.

N.NagataandS.Shirai,JHEP1501,029(2015).

χ01

q q

χ02

Z0

DirectdetecFon

0.6

0.8

1

1.2

1.4

103 104 105 106

resu

m/t

ree

|M2| [GeV]

10−49

10−48

10−47

10−46

10−45

10−44

SI

cros

sse

ctio

nσp SI

[cm

2] φ2 = 0

90

180

LUX exclusionNeutrino BG

N.NagataandS.Shirai,JHEP1501,029(2015).

0.60.8

11.21.4

103 104 105 106

resu

m/t

ree

|M2| [GeV]

1049

1048

1047

1046

1045

1044

SIcr

oss

sect

ionp SI

[cm

2] 2 = 0

90180

LUX exclusionNeutrino BG

Figure 8: SI scattering cross sections of the Higgsino DM with a proton as functions of |M2| in solidlines. Here we take tan = 2, µ = 500 GeV, M1 = M2 and em = |M2|. Red-solid, green-dashed, andblue short-dashed lines correspond to 2 = arg(M2) = 0, /2 and , respectively. Upper blue-shadedregion is excluded by the LUX experiment [61]. Lower gray-shaded region represents the limitationof the direct detection experiments due to the neutrino background [69]. Lower panel represents thee↵ects of the resummation on the calculation.

5 Electric Dipole Moments

Generally, the MSSM induces new sources of CP violations, which may lead to large electric dipole

moments (EDMs) of the SM fermions. One of the important contributions comes from one-loop

diagrams which includes SUSY scalar particles. Another significant contribution is two-loop dia-

grams without the SUSY scalar particles. In the present “lonely Higgsino” scenario (typically when

em 10 TeV), the latter contribution is dominant.

As we noted above, the mass di↵erence between the neutral components depends on the new

CP phases in the e↵ective interactions in Eqs. (4) and (8), and their e↵ects can be probed with the

EDMs. The dominant contribution to the EDMs comes from the two-loop Barr-Zee diagrams [70]

shown in Fig. 9 [71–73]. To evaluate the contribution, let us first show the Higgs-charged Higgsino

vertex:

Lint = Re(d2)vh eH+ eH+ + Im(d2)vh eH+i5 eH+ , (52)

and the CP-odd part (the second term) is relevant to our calculation.

The definition of the EDMs of fermion f is

LEDM = i

2dff

µ5Fµf . (53)

15

SIcrosssecYonsignificantlydependsontheCPphase.DirectdetecYonexperimentsnowstartprobingthisscenario.

χ0

q

h0

χ0 χ0 χ0

h0

qg

Q

g

N.NagataandS.Shirai,JHEP1501,029(2015).

0.60.8

11.21.4

103 104 105 106

resu

m/t

ree

|M2| [GeV]

1049

1048

1047

1046

1045

1044

SIcr

oss

sect

ionp SI

[cm

2] 2 = 0

90180

LUX exclusionNeutrino BG

Figure 8: SI scattering cross sections of the Higgsino DM with a proton as functions of |M2| in solidlines. Here we take tan = 2, µ = 500 GeV, M1 = M2 and em = |M2|. Red-solid, green-dashed, andblue short-dashed lines correspond to 2 = arg(M2) = 0, /2 and , respectively. Upper blue-shadedregion is excluded by the LUX experiment [61]. Lower gray-shaded region represents the limitationof the direct detection experiments due to the neutrino background [69]. Lower panel represents thee↵ects of the resummation on the calculation.

5 Electric Dipole Moments

Generally, the MSSM induces new sources of CP violations, which may lead to large electric dipole

moments (EDMs) of the SM fermions. One of the important contributions comes from one-loop

diagrams which includes SUSY scalar particles. Another significant contribution is two-loop dia-

grams without the SUSY scalar particles. In the present “lonely Higgsino” scenario (typically when

em 10 TeV), the latter contribution is dominant.

As we noted above, the mass di↵erence between the neutral components depends on the new

CP phases in the e↵ective interactions in Eqs. (4) and (8), and their e↵ects can be probed with the

EDMs. The dominant contribution to the EDMs comes from the two-loop Barr-Zee diagrams [70]

shown in Fig. 9 [71–73]. To evaluate the contribution, let us first show the Higgs-charged Higgsino

vertex:

Lint = Re(d2)vh eH+ eH+ + Im(d2)vh eH+i5 eH+ , (52)

and the CP-odd part (the second term) is relevant to our calculation.

The definition of the EDMs of fermion f is

LEDM = i

2dff

µ5Fµf . (53)

15

EDMs

0.6

0.7

0.8

0.9

1

103 104 105 106 107

resu

m/t

ree

|M2| [GeV]

10−32

10−31

10−30

10−29

10−28

10−27

Ele

ctro

nE

DM

[ecm

]

ACME exclusion

−dhγe

−dhZe

dWWe

0

50

100

150

200

250

300

350

103 104 105 106 107 108 109 1010

arg(M

2)

[deg

]

|M2| [GeV]

log10(|de| [ecm])without resum

-33-32-31-30-29-28

γ

h γ, Z

f f

χ+ χ+

W± W±

χ0

γ

EDMboundhasalreadyrestrictedparameterspace.

RadiaFvelyinducedmassspliBng

250

260

270

280

290

300

310

320

330

340

350

200 400 600 800 1000 1200 1400

∆m

+| rad

[MeV

]

|µ| [GeV]

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