SUSY Search at Future Collider and Dark Matter Experiments D. P. Roy Homi Bhabha Centre for Science...
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Transcript of SUSY Search at Future Collider and Dark Matter Experiments D. P. Roy Homi Bhabha Centre for Science...
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