Transcript DPRoy
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+
Wπ0sγs
χ
W
χ
W
W
vσWW ~ 10-26 cm3/s
Cont. γ Ray Signal
(But too large π0γ 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=0.001srγ 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 & m2 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