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 & BinoLSP
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
−χ
e,
~µν
e e
γe~
0χde
)(
10
~~
~,
e
e
mm
TeVm
νν
ν
µ
µ
≅
>)10(
10
2
,
~
−<
>
A
e TeVm
µφSplit SUSY solves 2 at the cost of
aggravating1.
DCTeVm
BANoTeVm
o
f
&1
)&(1
,
~
⇒≈
⇒>>>
±χ
We shall consider a more
moderate option, allowing
TeVmf
10010~ −=
Nature of the Lightest Superparticle (LSP) in the MSSM:
Astrophysical Constraints ⇒ Colourless & Chargeless LSP
Direct DM Detection Expts ⇒ LSP not Sneutrino
ud HcHcWcBcLSP~~~~
4321
0
1 +++=≡→∴ χχ
Diagonal elements : M1, M 2, ±µ in the basisud HHHWB
~~~&
~,
~2,1 ±=
Nondiagonal elements < MZ
Exptl Indications ⇒⇒⇒⇒ M1, M 2, µ > 2MZ in mSUGRA HorWB~~
,~
≅⇒ χ
Exception : Mii ≈ Mjj⇒ tan 2θij = 2Mij / (Mii – Mjj) large HWHB~~
,~~
−−=⇒ χ“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 ≈=≈= αααα
||
2
2/1
2
2
2
01
2
2
2
22222
)tan,,()tan,,(
5tan@1tan
tan2/
mhCmhCM
MMM
MEWSB
titiHu
HuHuHd
Z
βαβα
ββ
βµ
ε ≈−
+=−
>−≈−
−=+⇒
RGE:
Hyperbolic Br (tan β > 5) of µ 2 :
Imp Weak Sc Scalar mass MHu
(LEP)
LSPHMmm
LSPBMmm
−⇒<⇒>>
−⇒>⇒≈~
~
12/10
12/10
µ
µ
Chattopadhyay et al
m0 ~ 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 ~~ ≅τ
B~
τ~ τττ
γ
FP→
CA−↑τ~
LSPH −←~
Anns.Re↑
%)10(:~1~ ≈≅− withinMmCoAnn ττ 12:.Re MMAnns A ≅
)~~
(: 1 HBMPtFocus −=≅− χµχ
χZ
f
f
)7(
1:~
0
~ 0,
TeVmm
TeVMLSPHH
>≈
≅≅− ±
φ
µ
f
f±H~
0~H
W
4,32,1
2
4
2
3
, ccgg
ccg
HA
Z
∝
−∝
χχχχ
χχ
f
fA
χ
χ
ud HcHcWcBc~~~~
4321 +++=χ
Wino LSP (mAMSB model)
SUSY braking in HS in communicated to the OS via the Super-Weyl Anomaly Cont. (Loop)
2
0
2
2/3
2
2/3
2/32
2
332/32
2
222/32
2
112/3
4
1&
163,
16,
165
33
mmyg
mmy
A
mg
Mmg
Mmg
Mmg
M
yg
y
y
g
+
∂∂
+∂∂
−=−=
−===⇒=
βγ
βγβ
πππ
β
φ
λ
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 −=≅−±=− φµ
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 ∉→→∉→→ χχχχ ~~;~~
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
222
2/1
2
0
2
2/1
2
2
2
0
3/2
2
0
2 2/2)2/3(
Msmallmm
MmmmCmymM ZtHu
≈⇒>>
−−=−+=−−=≈≈
µ
µε
T
ji
t
dutg
dutt
leptonsWbgg
Wbbtttg
TeVmTeVmTeVm
TeVmTeVm
CmmmCmmCmmymm
∉+→+→⇒
→→⇒
≥==⇒
===
+=+=+−=
+
)(44~~
...22,~
2.2,5.1,3.1
10tan&5.0,2
;)3/1(
0~
~,~~~
2/10
2
2/1
2
0
2~
,~2
2/1
2
0
2
2/1
2
0
3/2
2
0
2~
1
1
1
χχχ
βInverted
Hierarchy
Chattopadhyay et al ljetsb T )41(4 −+∉++Focus Pt SUSY
Signal at LHC
Guchait & Roy
µ >0
µ<0
τ~ Co-annihilation region
χτττνχ
χτ
→→
≅±
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 χττ →
χχ ≡≡ ±111
~,
~ZW
:0
321jet
s−
±± →τ
ππντ 1-prong hadronic τ decay (BR≈0.5)
jetp
pR
−
±
=τ
π
With pT > 20 GeV cut for the τ-jet the τ misid. Probability
from 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 most
Of the signal.
Higgsino & Wino LSP Signals at CLIC:
)~
(~
)2.0(10; 0
,WHGeVmmmqq
Z ↵<−≡∆→→ ±−+−+
χχγ χχππχχ
⇒π± are too soft to detect at LHC without any effective tag
⇒Must go to an e+e- Collider with reqd. beam energy (CLIC)
W,Be+
e-
γ
χ+
χ-
e+
e-
γ
W
ν
ν
Chen, Drees, Gunion
OPAL (LEP) )~
&~
(90 WHGeVm >⇒ χ
χγγθ msEsM rec 2)/21(,10 2/1 >−=> o
o)2(1)100(50sin: min
3
min >⇒>⇒≅→ −+−+ θθγ γγθ GeVEsEeeee T
TeV
T
∆m < 1 GeV ⇒⇒⇒⇒ χ± and /or decay π± track with displaced vertex in MVX
∆m > 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
γ
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
∆m = 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. ∆m
±W~ ±
W~
±W~
γ, Z
Discovery potential is primarily determined by the number of Signal events.
103
102
# ev
Sig ~ 100 (300) events with
Unpolarized (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 +++=χ
4,32,1
2
4
2
3 & ccgccg HZ ∝−∝ χχχχ
Best suited for Focus pt. region ⇒Less for co-ann & res.ann regions B
HB~
~~
≅
−=
χ
χ
τ~
Unsuited for (Suppressed both by Hχχ coupling and large χ mass)WH~
&~
≅χ
2. Indirect Detection via HE ν from χχ annihilation in the Sun (Ice Cube,Antares)
χ
χ
p
p
Z
Spin dep.
ud
Zp
trapann
HHHWBfor
PtFocHBmixedOKfor
ccgRR
~~~&
~,
~0
.)~~
(
)( 22
4
2
3
2.
±≡≅⇒
−=⇒
−∝∝∝=
χ
χ
σ χχχχχχ
3. Detection of HE γ Rays from Galactic Centre in
ACT (HESS,CANGAROO,MAGIC,VERITAS) WH~
&~
≅χ
χ
χ
χ+
W
W
χ
χ
χ+
W→→→→π0s→→→→γs vσWW ~ 10-26 cm3/s
⇒⇒⇒⇒Cont. γ Ray Signal
(But too large π0→→→→γ from Cosmic Rays)
W
W
W
γ
γ(Z)
vσγγ~ vσγZ ~ 10-27-10-28 cm3/s
⇒Discrete 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
2
2
ρψ
ψσψφ
γγγψρπ
σψφ
χγγ
γχ
γγ 321
∫∆Ω=0.001srJ(0)dΩ ≈ 1 sr (Cuspy:NFW),
103 (Spiked), 10-3 (Core)
∫∆Ω=0.001srφφφφγ dΩ (NFW)
←←←←Discovery limit of ACT
Chattopadhyay et al
mSUGRA
mAMSB
)()(001.0
NFWd∫=∆Ω
Ωψφγ
←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 models
H~
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
2/101
222
2/1
2
0
2
0
2
0
2/101
222
2/1
2
0
2
0
2~
0
2
0
222
2/1
2
2
2~
0
3/2
2
0
2
µµ
µµε
µ
1)
J.Ellis et al,….
2)
LSPH
MCmMF
mmMCUniversalmMF
FSU
jiM
FMM
G
S
G
S
S
ji
Pl
ijS
i
G
i
−⇒
<⇒≅⇒×=⇒=
≈>⇒≅⇒=⇒=
+++=⊗⊃
=∈≡
~
4.1)1,2,10(200
@2)(1
200752412424:)5(
3,2,1&;
122/13,2,1
2/10122/13,2,1
µ
µ
λλλ
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
−≠
−=⇒⊄⊗≠
∈∈
φ
λ
φλ φφλλ†
mφ (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 & mφ2 at one-loop level
⇒ M2 < M1 < M3 similar to the AMSB (⇒ Wino LSP) & mφ ~ 10 Mλ
Brignole, Ibanez & Munoz ‘94
TeVmTeVMW
21~ 102 −≈⇒≈ φ
In these models:
Bino LSP in Non-universal
Gaugino Mass Model
M3 = 300, 400, 500 & 600 GeV
King, Roberts & Roy 07
Bulk annihilation region of
Bino DM (yellow) allowed in
Non-universal gaugino mass
models
Light right sleptons
Even left sleptons lighter than Wino
=>Large leptonic BR of SUSY
Cascade deacy via Wino