DPRoy

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
~
γ
e~
e
 ,e

e
0
de
m~ ,e  10 TeV
m ~e  10 TeV
( m~  m~e )
(  , A  10
We shall consider a more
moderate option, allowing
m ~f  10  100 TeV
2
)
Nature of the Lightest Superparticle (LSP) in the MSSM:
Astrophysical Constraints  Colourless & Chargeless LSP
Direct DM Detection Expts  LSP not Sneutrino
 LSP    
0
1
~
~
~
~
 c 1 B  c 2W  c 3 H d  c 4 H u
~ ~
~
~
~
Diagonal elements : M1, M 2, ±μ in the basis B , W & H 1, 2  H d  H u
Nondiagonal elements <
MZ
Exptl Indications  M1, M 2, μ > 2MZ in mSUGRA
Exception : Mii ≈ Mjj  tan 2θij = 2Mij / (Mii – Mjj) large 
~ ~ ~
   B , W or H
~
~ ~
~
  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)
~
B : M 1  ( 1 /  G ) m 1 / 2
RGE ( Weak Sc masses)
~
 0 . 4 m 1 / 2 & W : M 2  ( 2 /  G ) m 1 / 2  0 . 8 m 1 / 2
Imp Weak Sc Scalar mass MHu
EWSB    M
2
2
Z
/2 
M
2
Hd
tan
||
RGE:  M
2
Hu
M
2
2
Hu
tan
 1
2

 M
2
Hu
(LEP)
 C 1 ( i , h t , tan  ) m 0  C 2 ( i , h t , tan  ) m 1 / 2


2

2
2
Hyperbolic Br (tan β > 5) of μ 2
:
@ tan   5
~
m 0  m 1 / 2    M 1  B  LSP
~
m 0  m 1 / 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
~
f
B
~
f
~
B
f
Large sfermion mass  too large Ωh2
Except for the stau co-ann. region
m ~  m B~ ~
~
B



~
 H  LSP
 Re s. Ann
FP
 ~  CA
~
~
~  CoAnn : m~  M 1 ( within  10 %)
~ ~
Focus  Pt :   M 1 (   B  H )
~
H  LSP : M
~
~
  c 1 B  c 2W  c 3 H d  c 4 H u
~  ,0
H
   1TeV
( m   m 0  7 TeV )
Re s . Ann : M


f
Z
~
H
~0
H

A
 2M 1

f
A
f
f
g Z   c 3  c 4
f
g A  , g H   c1, 2 c 3 , 4
2
W
f
2
Wino LSP (mAMSB model)
SUSY braking in HS in communicated to the OS via the Super-Weyl Anomaly Cont. (Loop)
M


Ay  
g
g
y
y
m3/2  M 1 
2
m 3 / 2 & m
33
2
5 16 
2
2
g1
2
m3/2 , M
2

g2
16 
2
m3/2 , M
3
 3
g3
16 
 2
1  

2
  
g 
 y  m 3 / 2  m 0
4  g
y

m3/2 , m0 , tan β, sign (μ)
RGE  M1 : M2 : |M3| ≈ 2.8 : 1 : 7.1 including 2-loop conts
2
m3/2
Chattopadhyay et al
~0 ~0
W (H )
W
~ ~
W (H )
W
~0 ~0
W (H )
~ ~
W (H )
f
W
f
~0 ~0
W (H )
~
~
W  LSP : M 2  2 . 1  0 . 2TeV & H  LSP :   1TeV ( m   10  30 TeV )
Robust results, independent of other SUSY parameters
(Valid in any SUSY model with Wino(Higgsino) LSP)
Bino LSP Signal at LHC :
~
~
~
~
q q  q q   jj T ; g g  q q q q   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)
Focus Point Region: M
2
Hu
 m 0  (3 / 2 ) y t m 0  C 2 m1 / 2    m 0  2 m1 / 2     M


2
2
2
2
2
2
2
Z
/2
2
2 /3
m 0  m 1 / 2  small   M 1
m ~t  m 0  y t m 0  Cm 1 / 2  (1 / 3 ) m 0  Cm 1 / 2 ; m u~ , d~  m 0  Cm 1 / 2
1

2
Inverted
Hierarchy
2
2
2
2
2
2/3
m 0  2 TeV , m 1 / 2  0 . 5TeV & tan   10
 m g~  1 . 3TeV , m ~t  1 . 5TeV , m u~ , d~  2 . 2 TeV
1
~
t1
0

~
 g 
t t  i , t b  j  2 b 2W  ...
 g~ g~  4 b  4W (  leptons )   T
2
2
2
Focus Pt SUSY
Signal at LHC
Chattopadhyay et al
4 b  jets   T  (1  4 ) l
~
Guchait & Roy
Co-annihilation region
m ~1  m 
μ >0
 1   ~1 , ~1  

BR ≈ 1
BR = 1
τ is soft, but Pτ≈+1
μ<0
One can use Pτ to detect the
Soft τ coming from
~1   .
~
 ~
W1   1 , Z 1  
R 
p 
p   jet



  
s : 1-prong hadronic τ decay (BR≈0.5)
0
  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.
Chottopadhyay et al
Higgsino & Wino LSP Signals at CLIC:
 ,Z

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
χ+
e+
W,B
e-

ν
e+
W
χ-
γ

ν
e-
~
~
OPAL (LEP)  m   90 GeV ( H & W )

  10 , M rec 


s (1  2 E /
s)
1/ 2
 2m
γ

 min

e e   e e : E T

 s sin  min  E T  50 (100 ) GeV    1( 2 )
3 TeV
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

B
S
B
1
S
&
1000

1
50
&
1
B
S
 1( LEP )
B
103
(χ± decay π± tracks)
Polarized e- (80% R) & e+ (60% L) beams :


e L e R  2 % Pr obability ( 25 % Unpolarize d )
 Suppression of Bg by 0.08 & Sig by 0.8  Increase of S/B by ~ 10
# ev
104

E T  100 GeV 
102
S
B

1
50
&
S
B
3
Prompt π± tracks in the Background from Beamstrahlung
e+
e-
χ+
W,B
γ
χ
e+
π+
ν
γ
γ
χ- χ πe-
Beamstrahlung Bg f ≈ 0.1:
S
B
3
S
π+
W
π
ν
γ
 10
fB
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
~
~
~
~
  c 1 B  c 2W  c 3 H d  c 4 H u
g Z   c 3  c 4 & g H   c1 , 2 c 3 , 4
2
2
~
Best suited for Focus pt. region 
~
Less for ~ co-ann & res.ann regions   B
~
~
Unsuited for   H & W (Suppressed both by Hχχ coupling and large χ mass)
χ
~
  B  H
Spin ind.
Ge
2. Indirect Detection via HE ν from χχ annihilation in the Sun (Ice Cube,Antares)
χ
p
Z
Spin dep.
χ
p
 R

 p  g Z   ( c 3  c 4 )
~
~
 OKfor   mixed ( B  H ) Foc . Pt
~ ~
~
~
~
 0 for   B , W & H  H d  H u
ann .
R 
trap
2
2
2
2
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
2

dl ( ) ; N   2 (  ),1(  Z )
LS DMenergy  density
  ( )  1 . 87  10
J ( ) 
 (l )
 14
( N  v  / 10
 28
1
cm s )( 1TeV / m  ) J ( ) cm
3
2
2
1
s sr
1
  ( l ) dl /[( 0 . 3GeV / cm )  8 . 5 kpc ]
2
LS
3
2
∫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
m
2
Hu
m
2
0 Hu

3
y t m 0 ~t  C 2 m 1 / 2     M


2
2
2
2
2
2
Z
/2
2/3
m 0 Hu  m 0 ~t  m 0   m 0  2 m 1 / 2     M Z / 2    M 1 @ m 0  m 1 / 2
2
2
2
2
2
2
But : m 0 Hu  3 m 0  2 m 0  2 m 1 / 2     M
~
J.Ellis et al,….
 H  LSP
2
2
2
2
2
2
2
Z
/ 2    M 1 @ m 0  m1 / 2
2)
M
G
i
 M
i

FS
M
ij
 i  j ; i & j  1, 2 , 3
Pl
SU ( 5 ) : F S  24  24  1  24  75  200
F S  1  M 1 , 2 , 3  m 1 / 2 (Universal )  C 2  2    M 1 @ m 0  m 1 / 2
G
F S  200  M 1 , 2 , 3  (10 , 2 ,1)  m 1 / 2  C 2  1 . 4    M 1
~
 H  LSP
Chattopadhyay & Roy,….
G
Wino LSP in 1)Nonminimal AMSB & 2)String models
1) Tree level SUSY breaking contributions to gaugino and scalar masses
†
M 
FS
M
 ; m  
2
Pl
FS
M
FS
2
Pl
 *
F S  1( or 24  24  F S )  M   0 @ tree  level
But : m   0 @ tree  level ( Symm .Considerat ion )
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: M ~  2 TeV  m   10 1  2 TeV
W
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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