SUSY Search at Future Collider and Dark Matter Experiments

Report
SUSY Search at Future Collider
and Dark Matter Experiments
D. P. Roy
Homi Bhabha Centre for Science Education
Tata Institute of Fundamental Research
Mumbai – 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
μ
t
~
t
mh > 114 GeV (LEP)  m ~t > 1 TeV
Split SUSY solves 2 at the cost of
aggravating1.
m ~f  1TeV  No( A & B)
m  ,o  1TeV  C & D
γ
e
~
 ,e
m~ ,e  10TeV
( m~  m~e )
γ
e~
e

e
0
de
m~e  10TeV
(  , A  10  2 )
We shall consider a more
moderate option, allowing
m~f  10 100TeV
Nature of the Lightest Superparticle (LSP) in the MSSM:
Astrophysical Constraints  Colourless & Chargeless LSP
Direct DM Detection Expts  LSP not Sneutrino
~
~
~
~
 LSP      c1B  c2W  c3 Hd  c4 Hu
0
1
~ ~ ~
~
~
Diagonal elements : M1, M 2, ±μ in the basis B ,W & H1, 2  H d  H u
Nondiagonal elements <
MZ
Exptl Indications  M1, M 2, μ > 2MZ in mSUGRA
~ ~ ~
   B,WorH
Exception : Mii ≈ Mjj  tan 2θij = 2Mij / (Mii – Mjj) large
~ ~ ~ ~
   B  H ,W  H
“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)
~
~
B : M1  (1 / G )m1/ 2  0.4m1/ 2 &W : M 2  (2 / G )m1/ 2  0.8m1/ 2
Imp Weak Sc Scalar mass MHu
2
2
2
M

M
tan

2
EWSB   2  M Z2 / 2  Hd 2 Hu
  M Hu
@ tan   5
tan   1
||
(LEP)
RGE:
2
2
2
 M Hu
C
(

,
h
,
tan

)
m

C
(

,
h
,
tan

)
m
0
1/ 2
1 i t
2 i t

2
Hyperbolic Br (tan β > 5) of μ 2
:
~
m0  m1/ 2    M 1  B  LSP
~
m0  m1/ 2    M 1  H  LSP
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
f
~
f
~
B
f
Large sfermion mass  too large Ωh2
Except for the stau co-ann. region
m~  mB~ ~
~
B



~
 H  LSP
 Re s. Ann
FP
 ~  CA
~
~
~
~
  c1B  c2W  c3 Hd  c4 Hu

~  CoAnn: m~  M1 (within  10%) Re s. Ann: M A  2M1
~ ~
Focus Pt :   M1 (  B  H )
~
H  LSP : M H~  , 0    1TeV
(m  m0  7TeV )


f
Z
~
H
~
H0
W

f
A
f
f
g Z  c32  c42
f
g A , g H  c1, 2 c3, 4
f
Wino LSP (mAMSB model)
SUSY braking in HS in communicated to the OS via the Super-Weyl Anomaly Cont. (Loop)
M 
g
g
y
m3 / 2
g 32
33 g12
g 22
 M1 
m3 / 2 , M 2 
m3 / 2 , M 3  3
m3 / 2
2
2
2
5 16
16
16
 2
1  

Ay  
m3 / 2 & m   
g 
 y m3 / 2  m02
y
4  g
y

2
m3/2 , m0 , tan β, sign (μ)
RGE  M1 : M2 : |M3| ≈ 2.8 : 1 : 7.1 including 2-loop conts
Chattopadhyay et al
~ ~
W 0 (H 0 )
W
~ ~
W  (H  )
W
~ ~
W 0 (H 0 )
~ ~
W  (H  )
f
W
f
~ ~
W 0 (H 0 )
~
~
W  LSP : M 2  2.1  0.2TeV & H  LSP :   1TeV (m  10  30TeV )
Robust results, independent of other SUSY parameters
(Valid in any SUSY model with Wino(Higgsino) LSP)
Bino LSP Signal at LHC :
~
~
~
~
q q  qq   jj T ; gg  qq qq   jjjj T
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)
2
Focus Point Region: M Hu
2
2
2
2
2
 m02  (3 / 2) yt m02  C
m



m

2
m




M
0
1/ 2
Z /2
2 1/ 2

2 / 3
2
m0  m1/ 2  sm all   M 1
Inverted
Hierarchy
m~t21  m02  yt m02  Cm12/ 2  (1 / 3)m02  Cm12/ 2 ; mu~2,d~  m02  Cm12/ 2

2/3
m0  2TeV , m1/ 2  0.5TeV & tan   10
 mg~  1.3TeV , m~t1  1.5TeV , mu~ ,d~  2.2TeV
~
t1
~
g

t t i0 , t b j  2b2W ...
 g~g~  4b  4W ( leptons) 
T
Focus Pt SUSY
Signal at LHC
Chattopadhyay et al
4b  jets T (1  4)l
~ Co-annihilation region
Guchait & Roy
m~1  m
1  ~1 ,~1  
BR ≈ 1
μ >0
BR = 1
τ is soft, but Pτ≈+1
μ<0
One can use Pτ to detect the
Soft τ coming from
~1   .
~
 ~
W1  1 , Z1  
R
p 
p  jet
0
    

s : 1-prong hadronic τ decay (BR≈0.5)
  jet
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:
 ,Z
Chottopadhyay et al
q q        ; m  m   m 0




~ ~
 10(0.2)GeV H (W )
π± are too soft to detect at LHC without any effective tag
Must go to an e+e- Collider with reqd. beam energy (CLIC)
Chen, Drees, Gunion
e+
e-
χ+
ν
e+
W,B
γ
OPAL (LEP)
W
χ-
ν
e-
~ ~
 m  90GeV ( H & W )
   10 , M rec  s (1  2E  / s )1/ 2  2m
γ
ee  ee : ET min  
s sin min  ET  50(100)GeV    1(2)
3TeV
χ± decay tracks :
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)
Higgsino LSP Signal at 3 TeV CLIC : mχ = μ ≈ 1 TeV
e+
e-
χ+
W,B
γ
ν
e+
W
χ-
ν
eγ
Luminosity = 103 ev/fb
# ev
106
S
1
S

&
1
B 1000
B
S
1
S

&
 1( LEP)
B 50
B
103
(χ± decay π± tracks)
Polarized e- (80% R) & e+ (60% L) beams :
eLeR  2% Probability(25%Unpolarized )
 Suppression of Bg by 0.08 & Sig by 0.8  Increase of S/B by ~ 10
# ev
104
ET  100GeV 
102
S
1
S

&
3
B 50
B
Prompt π± tracks in the Background from Beamstrahlung
e+
e-
χ+
W,B
γ
χ
π+
e+
ν
γ
γ
χ- χ πe-
Beamstrahlung Bg f ≈ 0.1:
S
S
 3
 10
B
fB
π+
W
π
ν
γ
Size of fB present for Mrec < 2 TeV
 Estimate of fB for Mrec > 2 TeV
Any Excess over this Estimate
 χ signal & χ mass
Wino LSP Signal at 5 TeV CLIC : mχ = M2 ≈ 2 TeV
e+
e-
χ +  χ π+
W
ν
e+
W
χ- χ π-
γ
e-
ν
γ
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
γ, Z
~
W
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 W  as 2 heavily ionising particles along with
their decay π± tracks.
Discovery potential is primarily determined by the number of Signal events.
# ev
103
Sig ~ 100 (300) events with
Unpolarized (polarized) beams
102
The recoiling mass Mrec > 2mχ
helps to distinguish Sig from Bg
& to estimate mχ .
Bino, Higgsino & Wino LSP Signals in Dark Matter Detection Expts
1. Direct Detection (CDMS, ZEPLIN…)
χ
Ge
H
~
~
~
~
  c1B  c2W  c3 Hd  c4 Hu
gZ  c32  c42 & g H  c1, 2c3, 4
~
~
Best suited for Focus pt. region    B  H
Spin
ind.
χ
Ge
~
Less for ~ co-ann & res.ann regions   B
~ ~
Unsuited for   H &W (Suppressed both by Hχχ coupling and large χ mass)
2. Indirect Detection via HE ν from χχ annihilation in the Sun (Ice Cube,Antares)
χ
p
Z
Spin dep.
χ
p
ann .
R
 Rtrap   p  g Z2  (c32  c42 ) 2
~ ~
 OKfor  m ixed( B  H ) Foc.Pt
~ ~
~
~
~
 0 for  B , W & H  H d  H u
3. Detection of HE γ Rays from Galactic Centre in
ACT (HESS,CANGAROO,MAGIC,VERITAS)
W
χ
χ+
Wπ0sγs
χ
W
χ
W
W
vσWW ~ 10-26 cm3/s
Cont. γ Ray Signal
(But too large π0γ from Cosmic Rays)
γ
W
χ+
χ
~ ~
  H &W
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
 ( ) 
N  v
4m
2


(l ) 2

dl( ); N   2( ),1(Z )
LS DMenergy  density
 ( )  1.87 1014 ( N  v / 1028 cm3 s 1 )(1TeV / m ) 2 J ( )cm2 s 1sr 1
J ( )    (l ) 2 dl /[(0.3GeV / cm3 ) 2  8.5kpc]
LS
∫ΔΩ=0.001srJ(0)dΩ ≈ 1 sr (Cuspy:NFW),
103 (Spiked), 10-3 (Core)
mSUGRA
∫ΔΩ=0.001srγ dΩ (NFW)
Discovery limit of ACT
Chattopadhyay et al
mAMSB
~
W
~
H
  ( )d( NFW )
 0.001
Discovery limit of ACT
Chattopadhyay et al
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.
1)
Higgsino, Wino & Bino LSP in nonminimal SUSY models
~
H LSP in SUGRA models with nonuniversal 1)scalar & 2)gaugino masses
2
Hu
m
m
2
0 Hu
3
2
2
2
 yt m02~t  C
m




M
2 1/ 2
Z /2


2 2 / 3
2
m02Hu  m02~t  m02  m02  2m12/ 2    2  M Z2/ 2    M 1 @ m0  m1/ 2
But : m02Hu  3m02  2m02  2m12/ 2    2  M Z2 / 2    M 1 @ m0  m1/ 2
~
 H  LSP J.Ellis et al,….
2)
M
G
i
 M i 
FS
ij
M Pl
i  j ; i & j  1,2,3
SU (5) : FS  24  24  1  24  75  200
FS  1  M 1G, 2,3  m1/ 2 (Universal)  C2  2    M 1 @ m0  m1/ 2
FS  200  M 1G, 2,3  (10,2,1)  m1/ 2  C2  1.4    M 1
~
 H  LSP
Chattopadhyay & Roy,….
Wino LSP in 1)Nonminimal AMSB & 2)String models
1) Tree level SUSY breaking contributions to gaugino and scalar masses
†
M 
FS
M Pl
 ; m 
2
FS FS
M
2
Pl
 *
FS  1(or24  24  FS )  M   0 @ tree  level
But : m  0 @ tree  level( Sym m.Consideration)
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 & m2 at one-loop level
 M2 < M1 < M3 similar to the AMSB ( Wino LSP) & m ~ 10 Mλ
Brignole, Ibanez & Munoz ‘94
In these models:
MW~  2TeV  m  1012 TeV
M3 = 300, 400, 500 & 600 GeV
Bino LSP in Non-universal
Gaugino Mass Model
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

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