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SUSY Search at Future Collider and Dark Matter Experiments
D. P. RoyHomi Bhabha Centre for Science Education
Tata Institute of Fundamental ResearchMumbai – 400088, India
&Instituto de Fisica Corpuscular, CSIC-U. de Valencia
Valencia, Spain
Outline
• SUSY : Merits & Problems
• Nature of LSP : Bino, Higgsino or Wino
• DM Constraints on Bino, Higgsino & Wino LSP Scenarios ( mSUGRA & mAMSB Models)
• Bino LSP Signals at LHC
• Higgsino & Wino LSP Signals at CLIC
• Bino, Higgsino & Wino LSP Signals in DM Expts
• Nonminimal Models for Higgsino, Wino & Bino LSP
WHY SUSY :
A. Natural Soln to the Hierarchy Problem of EWSB
B. Natural (Radiative) Mechanism for EWSB
C. Natural Candidate for the cold DM (LSP)
D. Unification of Gauge Couplings @ GUT Scale
PROBLEMS WITH SUSY :
1. Little Hierarchy Problem 2. Flavour & CP Viol. Problem
-h
t t~
mh > 114 GeV (LEP) m > 1 TeVt~
γ
eμ
e,~
e e
γe~
0de
)(
10
~~
~,
e
e
mm
TeVm
)10(
102
,
~
A
e TeVm
Split SUSY solves 2 at the cost of aggravating1.
DCTeVm
BANoTeVm
o
f
&1
)&(1
,
~
We shall consider a moremoderate option, allowing
TeVmf
10010~
Nature of the Lightest Superparticle (LSP) in the MSSM:
Astrophysical Constraints Colourless & Chargeless LSPDirect DM Detection Expts LSP not Sneutrino
ud HcHcWcBcLSP~~~~
432101
Diagonal elements : M1, M 2, ±μ in the basis ud HHHWB~~~
&~
,~
2,1
Nondiagonal elements < MZ
Exptl Indications M1, M 2, μ > 2MZ in mSUGRA HorWB~~
,~
Exception : Mii ≈ Mjj tan 2θij = 2Mij / (Mii – Mjj) large HWHB~~
,~~
“Well-tempered Neutralino Scenario” Arkani-Hamed, Delgado & Giudice
DM Relic Density Constraints on Bino, Higgsino & Wino LSP Scenarios
mSUGRA: SUSY Br in HS communicated to the OS via grav. Int. m0 , m ½ , tanβ, A0 , sign (μ) at GUT scale ( A0 = 0 & +ve μ)
RGE ( Weak Sc masses)
2/12/1222/12/111 8.0)/(:~
&4.0)/(:~
mmMWmmMB GG
||
2
2/1
2
2201
2
22
22222
)tan,,()tan,,(
5tan@1tan
tan2/
mhCmhCM
MMM
MEWSB
titiHu
HuHuHd
Z
RGE:
Hyperbolic Br (tan β > 5) of μ 2 :
Imp Weak Sc Scalar mass MHu
(LEP)
LSPHMmm
LSPBMmm
~
~
12/10
12/10
Chattopadhyay et alm0 ~ m1/2 TeV (Bino LSP)
mh > 115 GeV m1/2 > 400 GeV (M1>2MZ)
also large sfermion mass
Bino does not carry any gauge charge Pair annihilate via sfermion exch
B~
B~
f~
f
f
Large sfermion mass too large Ωh2
Except for the stau co-ann. region
Bmm ~~
B~
~
FP
CA ~
LSPH ~
Anns.Re
%)10(:~1~ withinMmCoAnn 12:.Re MMAnns A
)~~
(: 1 HBMPtFocus
Zf
f
)7(
1:~
0
~ 0,
TeVmm
TeVMLSPHH
f
fH~
0~H
W
4,32,1
24
23
, ccgg
ccg
HA
Z
f
fA
ud HcHcWcBc~~~~
4321
Wino LSP (mAMSB model)
SUSY braking in HS in communicated to the OS via the Super-Weyl Anomaly Cont. (Loop)
20
22/3
22/3
2/32
23
32/32
22
22/32
21
12/3
4
1&
163,
16,
165
33
mmyg
mmy
A
mg
Mmg
Mmg
Mmg
M
ygy
y
g
m3/2 , m0 , tan β, sign (μ)
RGE M1 : M2 : |M3| ≈ 2.8 : 1 : 7.1 including 2-loop conts
)3010(1:~
&2.01.2:~
2 TeVmTeVLSPHTeVMLSPW
Chattopadhyay et al
)~
(~ 00 HW
)~
(~ 00 HW
)~
(~ HW
W
W
)~
(~ HW
)~
(~ 00 HW
W
f
f
Robust results, independent of other SUSY parameters(Valid in any SUSY model with Wino(Higgsino) LSP)
Bino LSP Signal at LHC :
TT jjjjqqqqggjjqqqq ~~;~~
Canonical Multijet + Missing-ET signal with possibly additional jets (leptons) from cascade decay (Valid through out the Bino LSP parameter space, including the Res.Ann Region)
Focus Point Region:
12/10
2222/1
20
22/1
2
220
3/2
20
2 2/2)2/3(
Msmallmm
MmmmCmymM ZtHu
T
jit
dutg
dutt
leptonsWbgg
Wbbtttg
TeVmTeVmTeVm
TeVmTeVm
CmmmCmmCmmymm
)(44~~...22,~
2.2,5.1,3.1
10tan&5.0,2
;)3/1(
0~
~,~~~
2/10
22/1
20
2~
,~2
2/120
22/1
20
3/2
20
2~
1
1
1
Inverted Hierarchy
Chattopadhyay et al ljetsb T )41(4 Focus Pt SUSYSignal at LHC
Guchait & Roy
μ >0
μ<0
~ Co-annihilation region
111
~
~,~1
mm
BR ≈ 1 BR = 1
τ is soft, but Pτ≈+1
One can use Pτ to detect the Soft τ coming from
.~1
111
~,
~ZW
:0jet
s
1-prong hadronic τ decay (BR≈0.5)
jetp
pR
With pT > 20 GeV cut for the τ-jet the τ misid. Probabilityfrom QCD jets goes down from 6% for R > 0.3 (pTπ±> 6 GeV) to 0.25% for R > 0.8 (pTπ± > 16 GeV), while retaining mostOf the signal.
Higgsino & Wino LSP Signals at CLIC:
)~
(~
)2.0(10; 0, WHGeVmmmqq Z
π± are too soft to detect at LHC without any effective tagMust go to an e+e- Collider with reqd. beam energy (CLIC)
W,Be+
e-
γ
χ+
χ-
e+
e-
γ
W
ν
νChen, Drees, Gunion
OPAL (LEP) )~
&~
(90 WHGeVm
msEsM rec 2)/21(,10 2/1
)2(1)100(50sin: min
3
min GeVEsEeeee T
TeVT
Δm < 1 GeV χ± and /or decay π± track with displaced vertex in MVX
Δm > 1 GeV 2 prompt π± tracks (Used by OPAL to beat ννγ background)
χ± decay tracks :
Chottopadhyay et al
Higgsino LSP Signal at 3 TeV CLIC : mχ = μ ≈ 1 TeV
Luminosity = 103 ev/fb
W,Be+
e-
γ
χ+
χ-
e+
e-
γ
W
ν
ν
# ev
106
103
)(1&50
1
1&1000
1
LEPB
S
B
S
B
S
B
S
(χ± decay π± tracks)
Polarized e- (80% R) & e+ (60% L) beams :
)%25(Pr%2 dUnpolarizeobabilityee RL
Suppression of Bg by 0.08 & Sig by 0.8 Increase of S/B by ~ 10
# ev
102
104
3&50
1100
B
S
B
SGeVET
Prompt π± tracks in the Background from Beamstrahlung
W,Be+
e-
γ
χ+
χ-
χ π+
χ π-
γ
W
ν
ν
e-
e+
γ
γ
Beamstrahlung Bg f ≈ 0.1: 103 fB
S
B
S
π+
π-
Size of fB present for Mrec < 2 TeV Estimate of fB for Mrec > 2 TeV
Any Excess over this Estimate χ signal & χ mass
Δm = 165 – 190 MeV for M2 ≈ 2 TeV & μ > M2
cτ = 3-7 cm (SLD MVX at 2.5 cm 2 cm at future LC)Tracks of as 2 heavily ionising particles along with their decay π± tracks.
W~
Wino LSP Signal at 5 TeV CLIC : mχ = M2 ≈ 2 TeV
We+
e-
γ
χ+
χ-
χ π+
χ π-
e+
e-
γ
W
ν
ν
Both Wino Signal and Neutrino Bg couple only to e-L & e+
R.
One can not suppress Bg with polarized beams. But one can use polarized beams to increase both Signal and Bg rates.
Polarized e-L (80%) & e+
R (60%) Probability of e-Le+
R = 72% (25% Unpolarized) Increase of Signal and Bg rates by factors of 72/25 ≈ 3.
Bg effectively suppressed due to a robust prediction of charged and neutral wino mas diff. Δm
W~ W
~W
~
γ, Z
Discovery potential is primarily determined by the number of Signal events.
103
102
# ev
Sig ~ 100 (300) events withUnpolarized (polarized) beams
The recoiling mass Mrec > 2mχ
helps to distinguish Sig from Bg& to estimate mχ .
Bino, Higgsino & Wino LSP Signals in Dark Matter Detection Expts
χ
χ
1. Direct Detection (CDMS, ZEPLIN…)
Ge
H
Spin ind.
Ge
ud HcHcWcBc~~~~
4321
4,32,124
23 & ccgccg HZ
Best suited for Focus pt. region Less for co-ann & res.ann regions B
HB~
~~
~
Unsuited for (Suppressed both by Hχχ coupling and large χ mass)WH~
&~
2. Indirect Detection via HE ν from χχ annihilation in the Sun (Ice Cube,Antares)
χ
χ
p
p
Z
Spin dep.
ud
Zptrapann
HHHWBfor
PtFocHBmixedOKfor
ccgRR
~~~&
~,
~0
.)~~
(
)( 224
23
2.
3. Detection of HE γ Rays from Galactic Centre in ACT (HESS,CANGAROO,MAGIC,VERITAS) WH
~&
~
χ
χ
χ+
W
W
χ
χ
χ+
Wπ0sγs vσWW ~ 10-26 cm3/sCont. γ Ray Signal(But too large π0γ from Cosmic Rays)
W
W
W
γ
γ(Z)
vσγγ~ vσγZ ~ 10-27-10-28 cm3/sDiscrete γ Ray Line Signal (Eγ ≈ m χ) (Small but Clean)
γ flux coming from an angle ψ wrt Galactic Centre
LS
LS densityDMenergy
kpccmGeVdllJ
srscmJmTeVscmvN
ZNdllm
vN
]5.8)/3.0/[()()(
)()/1)(10/(1087.1)(
)(1),(2;)()(4
)(
232
1122132814
22
∫ΔΩ=0.001srJ(0)dΩ ≈ 1 sr (Cuspy:NFW), 103 (Spiked), 10-3 (Core)
∫ΔΩ=0.001srγ dΩ (NFW)
Discovery limit of ACT
Chattopadhyay et al
mSUGRA
mAMSB
)()(001.0
NFWd
Discovery limit of ACT
Chattopadhyay et al
W~
H~
HESS has reported TeV range γ rays from GC. But with power law energy spec SNR Formidable Bg to DM Signal.The source could be GC (Sgr A*) or the nearby SNR (Sgr A east) within its ang. res. Better energy & angular resolution to extract DM Signal from this Bg.
Higgsino, Wino & Bino LSP in nonminimal SUSY modelsH~
LSP in SUGRA models with nonuniversal 1)scalar & 2)gaugino masses
LSPH
mmMMmmmmBut
mmMMmmmmm
MmCmymm
ZHu
ZtHu
ZttHuHu
~@2/223:
@2/2
2/2
3
2/101222
2/120
20
20
2/101222
2/120
20
2~0
20
2222/1
2
22~0
3/2
20
2
1)
J.Ellis et al,….
2)
LSPH
MCmMF
mmMCUniversalmMF
FSU
jiM
FMM
GS
GS
S
jiPl
ijS
iGi
~4.1)1,2,10(200
@2)(1
200752412424:)5(
3,2,1&;
122/13,2,1
2/10122/13,2,1
Chattopadhyay & Roy,….
Wino LSP in 1)Nonminimal AMSB & 2)String models
1) Tree level SUSY breaking contributions to gaugino and scalar masses
).(@0:
@0)2424(1
*;2
2
ionConsideratSymmleveltreemBut
leveltreeMForF
M
FFm
M
FM
SS
Pl
SS
Pl
S
†
m (tree) ~ 100 Mλ (AMSB) Giudice et al, Wells
2) String Th: Tree level SUSY breaking masses come only from Dilaton field, while they receive only one-loop contributions from Modulii fields.
Assuming SUSY breaking by a Modulus field Mλ & m2 at one-loop level
M2 < M1 < M3 similar to the AMSB ( Wino LSP) & m ~ 10 Mλ
Brignole, Ibanez & Munoz ‘94
TeVmTeVMW
21~ 102 In these models:
Bino LSP in Non-universalGaugino Mass Model
M3 = 300, 400, 500 & 600 GeV
King, Roberts & Roy 07
Bulk annihilation region ofBino DM (yellow) allowed in Non-universal gaugino massmodels
Light right sleptonsEven left sleptons lighter than Wino=>Large leptonic BR of SUSYCascade deacy via Wino
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