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HEP Pheno The Standard Model Beyond the SM
Research in High Energy Physics - Phenomenology
Shrihari Gopalakrishna
Institute of Mathematical Sciences (IMSc), Chennai
Graduate Student Talk
IMSc
Feb 2014
HEP Pheno The Standard Model Beyond the SM
Introduction
High Energy Physics - Phenomenology
Study of the Fundamental Particles, Physical Laws and
Organizing Principles in Nature & their Experimental
Tests
HEP Pheno The Standard Model Beyond the SM
Introduction
HEP - Phenomenology @ IMSc
Faculty Members
D. Indumathi
M.V.N Murthy
Nita Sinha
Rahul Sinha
Ravindran
Rajasekaran
Shrihari Gopalakrishna
Post-doctoral Fellows
Hijam Zeen Devi
Rahul Srivastava
Saurabh Gupta
Sunanda Patra
Tapasi Ghosh
Graduate Students
Arithra Biswas
Dibyakrupa Sahoo
Dhargyal
Rusa Mandal
Soumya Sadhukhan
Tanmoy Modak
Tuhin Subhra Mukherjee
INO Graduate Students
Lakshmi S. Mohan
Meghana K.K.
Kanishka Rawat
HRI Graduate Students
Maguni Mahakhud
Narayan Rana
Taushif Ahmed
Recent Alumni
Diganta Das (Dortmund)
Saveetha (IMSc)
Subhadip Mitra (Orsay/Paris)
Sumantha Pal (Edinburgh)
Tanumoy Mandal (HRI)
Pheno Club Email List : [email protected] sign-up for announcements
HEP Pheno The Standard Model Beyond the SM
Strucutre of the SM
The Building Blocks
[particleadventure.org]
Added Higgs in 2012Composites:
HEP Pheno The Standard Model Beyond the SM
Strucutre of the SM
Standard Model (SM) theoretical structure
Gauge Theory, Relativistic Quantum Field Theory (QFT)
SU(3)c ⊗ SU(2)L ⊗ U(1)Y gauge group (Internal Symmetry)
Strong, Weak, Electromagnetic Interactions
Eg: EM (QED) is U(1) gauge symmetry
Some Gauge Symmetries Spontaneously broken ⇒ Massive Weak gauge bosons
The Englert-Brout-Higgs-Guralnik-Hagen-Kibble Mechanism
HEP Pheno The Standard Model Beyond the SM
Strucutre of the SM
Standard Model (SM) theoretical structure
Gauge Theory, Relativistic Quantum Field Theory (QFT)
SU(3)c ⊗ SU(2)L ⊗ U(1)Y gauge group (Internal Symmetry)
Strong, Weak, Electromagnetic Interactions
Eg: EM (QED) is U(1) gauge symmetry
Some Gauge Symmetries Spontaneously broken ⇒ Massive Weak gauge bosons
The Englert-Brout-Higgs-Guralnik-Hagen-Kibble Mechanism
HEP Pheno The Standard Model Beyond the SM
Strucutre of the SM
Spontaneous Symmetry Breaking (SSB)
SSB : Microscopic laws symmetric, but ground state is NOT
Analogy: Spontaneous Magnetization in Condensed Matter Systems
[Fig by F. Heylighen]
Higgs Mechanism in QFT
L is invariant under Gauge Symmetry, but nonzero VacuumExpectation Value (VEV) of Higgs field breaks EW symmetry
HEP Pheno The Standard Model Beyond the SM
Strucutre of the SM
The Higgs Mechanism in the SM
L ⊃ (DµH)† DµH + µ2H†H − λ4!
(H†H)2
Spontaneous Breaking of Electroweak Symmetry
〈H〉= 1√2
(0v
)6= 0 (The E-B-Higgs-G-H-K Mechanism)
Give masses to W± , Z (γ massless)
Generates fermion masses
LYuk ⊃ −λuQHuR − λdQHdR − λeLHeR + h.c.
Under SU(3)c ⊗ SU(2)L ⊗ U(1)Y :
H = (1, 2)1/2
Q ≡(
uLdL
)= (3, 2)1/6 ; uR = (3, 1)2/3
L ≡(νLeL
)= (1, 2)−1/2 ; eR = (1, 1)−1
Complex Yukawa couplings λ =⇒ CP violation
Unitarize WW scattering [Lee, Quigg, Thacker, 1977]
But, mass of a fundamental scalar is not protected against getting largequantum correction. We’ll come back to this ...
HEP Pheno The Standard Model Beyond the SM
Strucutre of the SM
The Higgs Mechanism in the SM
L ⊃ (DµH)† DµH + µ2H†H − λ4!
(H†H)2
Spontaneous Breaking of Electroweak Symmetry
〈H〉= 1√2
(0v
)6= 0 (The E-B-Higgs-G-H-K Mechanism)
Give masses to W± , Z (γ massless)
Generates fermion masses
LYuk ⊃ −λuQHuR − λdQHdR − λeLHeR + h.c.
Under SU(3)c ⊗ SU(2)L ⊗ U(1)Y :
H = (1, 2)1/2
Q ≡(
uLdL
)= (3, 2)1/6 ; uR = (3, 1)2/3
L ≡(νLeL
)= (1, 2)−1/2 ; eR = (1, 1)−1
Complex Yukawa couplings λ =⇒ CP violation
Unitarize WW scattering [Lee, Quigg, Thacker, 1977]
But, mass of a fundamental scalar is not protected against getting largequantum correction. We’ll come back to this ...
HEP Pheno The Standard Model Beyond the SM
Strucutre of the SM
The Large Hadron Collider (LHC)
Seen the Higgs. Continue searching for more ...
HEP Pheno The Standard Model Beyond the SM
Strucutre of the SM
Higgs Production @ LHC
LHC is a p − p collider
P
P p contains partons: g , u, d , u, d , ...
x ≡√s√
S=14TeVParton momentum is fraction of
√S :
parton distribution function (pdf)
pp → h→ γγ @ LHC
σ(gg → h)
λf
f
Γ(h→ γγ)
λf
f W
W
HEP Pheno The Standard Model Beyond the SM
Strucutre of the SM
Higgs Production @ LHC
LHC is a p − p collider
P
P p contains partons: g , u, d , u, d , ...
x ≡√s√
S=14TeVParton momentum is fraction of
√S :
parton distribution function (pdf)
pp → h→ γγ @ LHC
σ(gg → h)
λf
f
Γ(h→ γγ)
λf
f W
W
HEP Pheno The Standard Model Beyond the SM
Strucutre of the SM
LHC Higgs Measurements
HEP Pheno The Standard Model Beyond the SM
Strucutre of the SM
Are we done?
I don’t think so ...
HEP Pheno The Standard Model Beyond the SM
Strucutre of the SM
Are we done?
I don’t think so ...
HEP Pheno The Standard Model Beyond the SM
Why BSM Physics?
Motivation for Physics Beyond the Standard Model (BSM)
Observational
What is the observed Dark Matter?
What generates the Baryon Asymmetry of the Universe (BAU)?
What generates the neutrino masses?
Theoretical
SM hierarchy problem (Higgs sector): MEW MPl
SM flavor problem: me mt
Explained by new dynamics?
Extra dimensions (Warped (AdS), Flat)SupersymmetryStrong dynamicsLittle Higgs
HEP Pheno The Standard Model Beyond the SM
Why BSM Physics?
Hierarchy problem in detail
LHC (and LEP) tell us that the Higgs boson is light mh = 126 GeV
L ⊃ 12µ
2 H†H − λ4!
(H†H
)2No symmetry protecting the Higgs mass!
tL, tR
−i yt√
2
h hδm2
h = − 3y2t
16π2 Λ2
tL, tR
−i yt√
2
h h
(Λ is momentum cut-off, say Mpl)
Quadratic divergence in the Higgs sector
HEP Pheno The Standard Model Beyond the SM
BSM Physics Possibilities
New physics possibilities
Belief that some new physics cures these problems
Look for these at the LHC
Supersymmetry[SG,Yuan,2004]
Extra-dimensions : (Warped or Flat)[Mandal, Mitra, Moreau, SG, Tibrewala 2011, 13][Agashe, Davoudiasl, SG, Han, Huang, Perez, Si, Soni
”2007, 08,
10] [Cao, SG, Yuan, 2003]
Strong dynamics (Note AdS-CFT correspondence)
Little Higgs
Neutrino mass connection and lepton number violation[EDM with Triplet Higgs: de Gouvea, SG, 2005]
Dark Matter candidates[SG, Jung, Lee, Wells, 2008, 09]
HEP Pheno The Standard Model Beyond the SM
BSM Physics Possibilities
New physics possibilities
Belief that some new physics cures these problems
Look for these at the LHC
Supersymmetry[SG,Yuan,2004]
Extra-dimensions : (Warped or Flat)[Mandal, Mitra, Moreau, SG, Tibrewala 2011, 13][Agashe, Davoudiasl, SG, Han, Huang, Perez, Si, Soni
”2007, 08,
10] [Cao, SG, Yuan, 2003]
Strong dynamics (Note AdS-CFT correspondence)
Little Higgs
Neutrino mass connection and lepton number violation[EDM with Triplet Higgs: de Gouvea, SG, 2005]
Dark Matter candidates[SG, Jung, Lee, Wells, 2008, 09]
HEP Pheno The Standard Model Beyond the SM
BSM Physics Possibilities
Precision Probes of BSM
In addition to Collider probes, New Physics can also be probed in:
Precision Electroweak Probes (S, T, Zbb)W,Z, γ
Flavor Changing Neutral Currents (FCNC)
K 0K 0 mixing, b → sγ , b → s `+`− , b → s s s, K → πνν, b → τνX , ...Relaxed with flavor alignment : MFV, flavor symmetries
(g − 2)µ, EDM, ...
Generally result in bound : MBSM & few − 100 TeV
HEP Pheno The Standard Model Beyond the SM
Supersymmetry
SUPERSYMMETRY
HEP Pheno The Standard Model Beyond the SM
Supersymmetry
Supersymmetry (SUSY)
Reviews: [Wess & Bagger]
Symmetry: Fermions ⇔ BosonsQ |Φ〉 = |Ψ〉 ; Q |Ψ〉 = |Φ〉Qα is a spinorial charge
SUSY algebra:Qα, Qβ
= 2σ
µ
αβPµ
Qα,Qβ
=Qα, Qβ
= 0
[Pµ,Qα] =[Pµ, Qα
]= 0
Under a SUSY transformation
δξφ =√
2ξψ
δξψ =i√
2σm ξ∂mφ+√
2ξF
δξF =i√
2ξσm∂mψ
δξAmn =i[(ξσn∂mλ+ ξσn∂mλ
)− (n↔ m)
]δξλ =iξD + σmnξAmn
δξD =ξσm∂mλ− ξσm∂mλ
HEP Pheno The Standard Model Beyond the SM
Supersymmetry
Supersymmetry (SUSY)
Reviews: [Wess & Bagger]
Symmetry: Fermions ⇔ BosonsQ |Φ〉 = |Ψ〉 ; Q |Ψ〉 = |Φ〉Qα is a spinorial charge
SUSY algebra:Qα, Qβ
= 2σ
µ
αβPµ
Qα,Qβ
=Qα, Qβ
= 0
[Pµ,Qα] =[Pµ, Qα
]= 0
Under a SUSY transformation
δξφ =√
2ξψ
δξψ =i√
2σm ξ∂mφ+√
2ξF
δξF =i√
2ξσm∂mψ
δξAmn =i[(ξσn∂mλ+ ξσn∂mλ
)− (n↔ m)
]δξλ =iξD + σmnξAmn
δξD =ξσm∂mλ− ξσm∂mλ
HEP Pheno The Standard Model Beyond the SM
Supersymmetry
Consequences
Solution to gauge hierarchy problem
tL, tR
−i yt√
2
h h +tL, tR
−iy2t2
h h
= 0
Λ2 divergence cancelled [Romesh Kaul, ’81, ’82] [Witten]
(Similarly W±,Z divergences cancelled by λ)
Lightest SUSY Particle (LSP) stable dark matter (if Rp conserved)
Gauge Coupling Unification - SUSY SO(10) GUTIncludes νR ⇒ Neutrino mass via seesaw
HEP Pheno The Standard Model Beyond the SM
Supersymmetry
Consequences
Solution to gauge hierarchy problem
tL, tR
−i yt√
2
h h +tL, tR
−iy2t2
h h
= 0
Λ2 divergence cancelled [Romesh Kaul, ’81, ’82] [Witten]
(Similarly W±,Z divergences cancelled by λ)
Lightest SUSY Particle (LSP) stable dark matter (if Rp conserved)
Gauge Coupling Unification - SUSY SO(10) GUTIncludes νR ⇒ Neutrino mass via seesaw
HEP Pheno The Standard Model Beyond the SM
SUSY breaking
SUSY breaking
Exact SUSY =⇒ Mψ = Mφ ; MA = Mλ
So experiment =⇒ SUSY must be broken
Supersymmetrize the SM + SUSY breaking → Minimal SupersymmtricStandard Model (MSSM)
HEP Pheno The Standard Model Beyond the SM
MSSM
125 GeV Higgs in the MSSM
At 1-loop [Haber, Hempfling, Hoang, 1997]
m2h ≈ m2
Z cos2(2β) +3g2
2 m4t
8π2m2W
[ln(
mt1mt2
m2t
)+
X2t
mt1mt2
(1− X2
t12mt1
mt2
)]where Xt = At − µ cotβ
mh = 125 GeV needs sizable loop contribution
Hard! Needs large mt1mt2
or large X 2t
But δm2Hu≈ 3g2
2 m4t
8π2m2W
[ln(
mt1mt2
m2t
)+
X2t
2mt1mt2
(1− X2
t6mt1
mt2
)]So fine-tuning necessary to keep m2
Z correct“Little hierarchy problem”
Mass scales [GeV]0 200 400 600 800 1000 1200 1400
0χ∼ l → l
~
0
χ∼ 0
χ∼ν τττ → ±χ∼ 2
0χ∼
0
χ∼ 0
χ∼ν τ ll→ ±χ∼ 2
0χ∼
0χ∼
0χ∼ H W →
2
0χ∼ ±χ∼
0χ∼
0χ∼ W Z →
2
0χ∼ ±χ∼
0χ∼0χ∼νν-l+ l→ -χ∼+χ∼
0χ∼
0χ∼ν lll → ±χ∼
2
0χ∼
0χ∼ bZ → b
~0
χ∼ tW → b~
0χ∼ b → b
~
H G)→ 0χ∼(0χ∼ t b → t~)0χ∼ W → ±χ∼ b (→ t~)0χ∼ W→ +χ∼ b(→ t~0χ∼ t → t~0χ∼ t → t~
0χ∼ q → q~
0χ∼ q → q~
))0
χ∼ W→ ±χ∼ t(→ b~
b(→ g~)
0χ∼γ →
2
0χ∼ qq(→ g~
)0
χ∼ W→±χ∼|0
χ∼γ→2
0χ∼ qq(→ g~
)0χ∼ W→±χ∼ qq(→ g~)
0χ∼ Z →
2
0χ∼ qq (→ g~
)0χ∼ ν± l→ ±χ∼ qq(→ g~)0χ∼ t→ t~ t(→ g~)0χ∼ |0χ∼ W→±χ∼ qq(→ g~)
0χ∼ |
0χ∼ τ τ →
2
0χ∼ qq(→ g~
)0
χ∼-
l+
l→2
0χ∼ qq (→ g~
0χ∼ tt → g~
0χ∼ bb → g~
0χ∼ qq → g~
0χ∼ qq → g~
SUS-13-006 L=19.5 /fb
SUS-13-008 SUS-13-013 L=19.5 /fb
SUS-13-011 L=19.5 /fbx = 0.25
x = 0.50x = 0.75
SUS-13-008 L=19.5 /fb
SUS-12-001 L=4.93 /fb
SUS-11-010 L=4.98 /fb
SUS-13-006 L=19.5 /fbx = 0.05
x = 0.50x = 0.95
SUS-13-006 L=19.5 /fb
SUS-13-012 SUS-12-028 L=19.5 11.7 /fb
SUS-12-005 SUS-11-024 L=4.7 /fb
SUS-12-028 L=11.7 /fb
SUS-13-008 SUS-13-013 L=19.5 /fb
SUS-13-014 L=19.5 /fb
SUS-13-004 SUS-13-007 SUS-13-008 SUS-13-013 L=19.4 19.5 /fb
SUS-13-013 L=19.5 /fbx = 0.20
x = 0.50
SUS-13-004 SUS-12-024 SUS-12-028 L=19.3 19.4 /fb
SUS-12-001 L=4.93 /fb
SUS-13-012 SUS-12-028 L=19.5 11.7 /fb
SUS-12-010 L=4.98 /fb x = 0.25x = 0.50x = 0.75
SUS-12-005 SUS-11-024 L=4.7 /fb
SUS-13-008 SUS-13-013 L=19.5 /fb
SUS-13-017 L=19.5 /fb
SUS-12-004 L=4.98 /fb
SUS-13-006 L=19.5 /fb
SUS-11-011 L=4.98 /fb
SUS-13-011 SUS-13-004 L=19.5 19.3 /fb left-handed topunpolarized top
right-handed top
SUS-11-024 SUS-12-005 L=4.7 /fb
SUS-11-021 SUS-12-002 L=4.98 4.73 /fbx = 0.25
x = 0.50x = 0.75
SUS-13-006 L=19.5 /fb x = 0.05x = 0.50
x = 0.95
SUS-13-006 L=19.5 /fb
SUS-11-030 L=4.98 /fb
glui
no p
rodu
ctio
nsq
uark
stop
sbot
tom
EW
K g
augi
nos
slep
ton
Summary of CMS SUSY Results* in SMS framework
CMS Preliminary
m(mother)-m(LSP)=200 GeV m(LSP)=0 GeVSUSY 2013
= 7 TeVs
= 8 TeVs
lspm⋅-(1-x)
motherm⋅ = xintermediatem
For decays with intermediate mass,
Only a selection of available mass limits*Observed limits, theory uncertainties not included
Probe *up to* the quoted mass limit
HEP Pheno The Standard Model Beyond the SM
MSSM
stop mass [GeV]
100 200 300 400 500 600 700 800
LSP
mas
s [G
eV]
0
50
100
150
200
250
300
350
400
450
500
W
=m1
0χ∼
-mt~
m
t
=m1
0χ∼
-mt~
m
SUSY 2013 = 8 TeVs
CMS Preliminary
productiont~-t
~
)1
0χ∼ t →t~ (-1SUS-13-004 0-lep+1-lep (Razor) 19.3 fb
)1
0χ∼ t →t~ (-1SUS-13-011 1-lep (leptonic stop)19.5 fb
, x=0.25)1
+χ∼ b →t~ (-1SUS-13-011 1-lep (leptonic stop)19.5 fb
Observed
ExpectedW
=m1
0χ∼
-m1
±χ∼m
gluino mass [GeV]
600 700 800 900 1000 1100 1200 1300 1400 1500
LSP
mas
s [G
eV]
0
100
200
300
400
500
600
700
800
900
ObservedSUSYtheory
σObserved -1 Expected
m(g
luin
o) - m
(LSP) =
2 m
(top)
m(g
luin
o) - m
(LSP) =
m(W
) + m
(top)
Nov 2013 = 8 TeVs
CMS Preliminary1
0χ∼ t t →g~ production, g~-g~
-1) 19.4 fbT+HTESUS-12-024 0-lep (-1SUS-13-004 0+1-lep (razor) 19.3 fb
-1 6) 19.4 fb≥jets
SUS-13-007 1-lep (n-1SUS-13-016 2-lep (OS+b) 19.7 fb-1SUS-13-013 2-lep (SS+b) 19.5 fb
-1SUS-13-008 3-lep (3l+b) 19.5 fb
[GeV]0
2χ∼
= m±1
χ∼m100 200 300 400 500 600 700 800
[G
eV]
0 1χ∼m
100
200
300
400
500
600
700
800
900Observed limits)ν∼/Ll
~, (via ±
1χ∼ 0
2χ∼ → pp
)ν∼/Ll~
, (via -
1χ∼ +
1χ∼ → pp
)Rl~
, (via ±1
χ∼ 0
2χ∼ → pp
)Rτ∼, (via ±1
χ∼ 0
2χ∼ → pp
)0
1χ∼)(W
0
1χ∼ (Z → ±
1χ∼ 0
2χ∼ → pp
)0
1χ∼)(W
0
1χ∼ (H → ±
1χ∼ 0
2χ∼ → pp
-1 = 19.5 fbint
= 8 TeV, LsCMS Preliminary
0
1χ∼
+ 0.5m±
1χ∼
= 0.5ml~
m
01χ∼
= m±
1χ∼mZ
+ m0
1χ∼ = m
±1χ∼m H
+ m0
1χ∼ = m
±1χ∼m
SUS-13-006
SUS-13-017
HEP Pheno The Standard Model Beyond the SM
Extra Dimension
EXTRA DIMENSION(S)
HEP Pheno The Standard Model Beyond the SM
Extra Dimension
Warped Extra Dimensions (WED, RS)
SM in background 5D warped AdS space [Randall, Sundrum 99]
ds2 = e−2k|y|(ηµνdxµdxν) + dy 2
Z2 orbifold fixed points:
Planck (UV) Brane
TeV (IR) Brane
R : radius of Ex. Dim.
k : AdS curvature scale (k . Mpl )
πR0
y
y=0
y=πR
UV
IR
Hierarchy prob soln:
IR localized Higgs : MEW ∼ ke−kπR : Choose kπR ∼ 34
Gauge Theory Dual may be a composite Higgs model
HEP Pheno The Standard Model Beyond the SM
Extra Dimension
Equivalent 4D theory
5D (compact) field ↔“Infinite” tower of 4D fields
Look for this tower at the LHC
SM
1st KK
2nd KK
Example:b
q′
q
t
ℓ+
W+(1) b
W+ν
HEP Pheno The Standard Model Beyond the SM
Extra Dimension
Warped Ex-Dim at LHC
Look for heavy Kaluza-Klein (KK) states : KK Gluon, Graviton, W, ZLEP precision electroweak constraints ⇒ V ′ & 2TeV
Example: W ′ → XX pp →W ′ → tb →Wbb → `νbb
0.0001
0.001
0.01
0.1
1
1 1.5 2 2.5 3 3.5 4 4.5 5MW ′ [TeV]
BR(W ′L+ → X X)
tL b-
W+ hTL b
-
χL t-L Z W+
u d-
νe e+
1e-10
1e-09
1e-08
1e-07
1e-06
1e-05
0.0001
0.001
0.01
500 1000 1500 2000 2500 3000 3500 4000 4500 5000
Diff
. cro
ss s
ectio
n [p
b/G
eV]
MTtb
pp → t b− : MT
2 TeV3 TeV4 TeV
SM
[Agashe, SG, Han, Huang, Soni, 2008]
q* (qg), dijetq* (qW)q* (qZ)
q* , dijet pairq* , boosted Z
e*, Λ = 2 TeVμ*, Λ = 2 TeV
0 1 2 3 4 5 6Z’SSM (ee, µµ)
Z’SSM (ττ)Z’ (tt hadronic) width=1.2%
Z’ (dijet)Z’ (tt lep+jet) width=1.2%
Z’SSM (ll) fbb=0.2G (dijet)
G (ttbar hadronic)G (jet+MET) k/M = 0.2
G (γγ) k/M = 0.1G (Z(ll)Z(qq)) k/M = 0.1
W’ (lν)W’ (dijet)
W’ (td)W’→ WZ(leptonic)
WR’ (tb)WR, MNR=MWR/2
WKK μ = 10 TeVρTC, πTC > 700 GeV
String Resonances (qg)s8 Resonance (gg)
E6 diquarks (qq)Axigluon/Coloron (qqbar)
gluino, 3jet, RPV0 1 2 3 4 5 6
gluino, Stopped Gluinostop, HSCP
stop, Stopped Gluinostau, HSCP, GMSB
hyper-K, hyper-ρ=1.2 TeVneutralino, cτ<50cm
0 1 2 3 4 5 6
Ms, γγ, HLZ, nED = 3Ms, γγ, HLZ, nED = 6Ms, ll, HLZ, nED = 3Ms, ll, HLZ, nED = 6
MD, monojet, nED = 3MD, monojet, nED = 6MD, mono-γ, nED = 3MD, mono-γ, nED = 6
MBH, rotating, MD=3TeV, nED = 2MBH, non-rot, MD=3TeV, nED = 2
MBH, boil. remn., MD=3TeV, nED = 2MBH, stable remn., MD=3TeV, nED = 2
MBH, Quantum BH, MD=3TeV, nED = 20 1 2 3 4 5 6Sh. Rahatlou 1
LQ1, β=0.5LQ1, β=1.0LQ2, β=0.5LQ2, β=1.0
LQ3 (bν), Q=±1/3, β=0.0LQ3 (bτ), Q=±2/3 or ±4/3, β=1.0
stop (bτ)0 1 2 3 4 5 6
b’ → tW, (3l, 2l) + b-jetq’, b’/t’ degenerate, Vtb=1
b’ → tW, l+jetsB’ → bZ (100%)T’ → tZ (100%)
t’ → bW (100%), l+jetst’ → bW (100%), l+l
0 1 2 3 4 5 6C.I. Λ , Χ analysis, Λ+ LL/RRC.I. Λ , Χ analysis, Λ- LL/RR
C.I., µµ, destructve LLIMC.I., µµ, constructive LLIM
C.I., single e (HnCM)C.I., single µ (HnCM)
C.I., incl. jet, destructiveC.I., incl. jet, constructive
0 5 10 15
HeavyResonances
4thGeneration
Compositeness
LongLived
LeptoQuarks
Extra Dimensions & Black Holes
Contact Interactions
95% CL EXCLUSION LIMITS (TEV)CMS EXOTICA
HEP Pheno The Standard Model Beyond the SM
Extra Dimension
ATLAS Extra Dimensions Limits (Moriond 2013)
HEP Pheno The Standard Model Beyond the SM
New Fermions?
Fourth (Chiral) Generation
SM has 3 generations. Why not a fourth generation?LHC strongly disfavors 4th Generation!
Reason: In a Chiral theory Mf and f f h both given by λf
gg → h→ γγ altered too much due to heavy Q4 with large λQ4
σ(gg → h)
λf
f
Γ(h→ γγ)
λf
f W
W
HEP Pheno The Standard Model Beyond the SM
New Fermions?
Vectorlike Fermions
Vector Like (VL) fermions: ψL , ψR : conjugate reps ofSU(3)c ⊗ SU(2)L ⊗ U(1)Y
Can write L ⊃ −MVLψψ consistent with SM Gauge Symmetryso don’t need large λ for large Mf
Vectorlike fermions Chiral (4-gen) fermions
M ok with Gauge Symmetry M only after EWSB i.e. 〈H〉
can be arbitrarily heavy Landau pole in Yukawa coupling
CC + NC tree-level decays only CC tree-level decays
loops decoupling some loops nondecoupling
HEP Pheno The Standard Model Beyond the SM
New Fermions?
Vectorlike fermion Probes
How do we look for ψVL directly @ LHC?
t′, b′, χ Signatures [SG, Mandal, Mitra, Moreau, Tibrewala, 2011, ’13]
How do the ψVL modify 1-loop Higgs production and decay @ LHC?[S.Ellis, Godbole, SG, Wells, Ongoing]
How do the ψVL modify precision EW observables (LEP)?[S.Ellis, Godbole, SG, Wells, Ongoing]
HEP Pheno The Standard Model Beyond the SM
New Fermions?
b′ Single Production - II
[SG, T.Mandal, S.Mitra, R.Tibrewala, arXiv:1107.4306]
Single Production : bg → b′Z → bZZ → bjj``
æ
æ
ææ
æ æ
400 600 800 1000 1200 1400 1600
0.0
0.2
0.4
0.6
0.8
1.0
Mb2HGeVL
Κb2bZ
Σ = 0.1 fb
1
10
100
1000
æ
æ
ææ
æ
500 1000 1500
0.0
0.2
0.4
0.6
0.8
1.0
Mb2HGeVL
Κb2bZ
L = 3000 fb-1
100
10
1
Cuts:
Rapidity: −2.5 < yb,j,Z < 2.5,Transverse momentum: pT b,j,Z > 0.1Mb2
,
Invariant mass cuts:MZ − 10 GeV < Mjj < MZ + 10 GeV,0.95Mb2
< M(bZ) OR (bjj) < 1.05Mb2.
HEP Pheno The Standard Model Beyond the SM
Dark Matter
Dark Matter Candidates from BSM
HEP Pheno The Standard Model Beyond the SM
Dark Matter
Observations tell us
Flat on large scales
Expansion is Accelerating
95% is unknown dark matter + dark energy
What is it?? The DARK SIDE rules!
HEP Pheno The Standard Model Beyond the SM
Dark Matter
Observations tell us
Flat on large scales
Expansion is Accelerating
95% is unknown dark matter + dark energy
What is it??
The DARK SIDE rules!
HEP Pheno The Standard Model Beyond the SM
Dark Matter
Observations tell us
Flat on large scales
Expansion is Accelerating
95% is unknown dark matter + dark energy
What is it?? The DARK SIDE rules!
HEP Pheno The Standard Model Beyond the SM
Dark Matter
What is the dark sector?
Dark Matter
Astrophysical objects? (Disfavoured)
MAssive Compact Halo Objects (MACHO) or Black Holes or . . .
Particle dark matter? More on this...
Hot or Warm or Cold Dark Matter (CDM)
Dark energy
HEP Pheno The Standard Model Beyond the SM
Dark Matter
What is the dark sector?
Dark Matter
Astrophysical objects? (Disfavoured)
MAssive Compact Halo Objects (MACHO) or Black Holes or . . .
Particle dark matter? More on this...
Hot or Warm or Cold Dark Matter (CDM)
Dark energy
HEP Pheno The Standard Model Beyond the SM
Particle DM Candidates
Particle DM Possibilities
LSP - Lightest Supersymmetric Particle
SuperWIMP - Gravitino (SUSY partner of graviton)
E-WIMP - Right-handed sneutrino (partner of neutrino)
WIMPzilla - Extremely massive particle
LKP - Lightest Kaluza-Klein Particle - Extra space dimensions
LTP - Lightest T-odd Particle - Little-higgs theory with Z2
Hidden sector DM
Your candidate here
HEP Pheno The Standard Model Beyond the SM
Particle DM Candidates
Particle DM Possibilities
LSP - Lightest Supersymmetric Particle
SuperWIMP - Gravitino (SUSY partner of graviton)
E-WIMP - Right-handed sneutrino (partner of neutrino)
WIMPzilla - Extremely massive particle
LKP - Lightest Kaluza-Klein Particle - Extra space dimensions
LTP - Lightest T-odd Particle - Little-higgs theory with Z2
Hidden sector DM
Your candidate here
HEP Pheno The Standard Model Beyond the SM
Particle DM Candidates
Particle Dark Matter (DM)
Self-Annihilation cross-section gives present DM Relic density
SM
ψ
ψ
Ω0h2 = 10−29xf
(eV−2
〈σv〉
)
Doesn’t apply to Non-thermal DM [Rt Sneutrino DM & LHC Signatures: de Gouvea, SG, Porod, 06]
HEP Pheno The Standard Model Beyond the SM
Particle DM Candidates
Particle Dark Matter (DM)
Self-Annihilation cross-section gives present DM Relic density
SM
ψ
ψ
Ω0h2 = 10−29xf
(eV−2
〈σv〉
)Doesn’t apply to Non-thermal DM [Rt Sneutrino DM & LHC Signatures: de Gouvea, SG, Porod, 06]
HEP Pheno The Standard Model Beyond the SM
DM Detection
Dark Matter Detection
Direct Detection
DM directly intereacts with a detector
Indirect Detection
Look for products of DM-DM annihilation
Collider Detection
DM carries away invisible momentum
HEP Pheno The Standard Model Beyond the SM
DM Detection
Direct Detection
ψ
φSM
φH
ψ
NN
WIMP Mass [GeV/c2]
Cro
ss−
sect
ion [
cm2]
(norm
alis
ed t
o n
ucl
eon)
131206083800
http://dmtools.brown.edu/ Gaitskell,Mandic,Filippini
101
102
103
10−50
10−48
10−46
10−44
10−42
10−40
10−38
Xenon10T, G3 expected sensitivity (2013)
LUX (2014/15) 300d projection (SI, 90% CL median expected)
LUX (2013) 85d 118kg (SI, 95% CL)
XENON100, 2012, 225 live days (7650 kg−days), SI
CRESST II commissioning run (2009) extended to low masses
CDMSII−Si (Silicon), c58 95% CL , SI (2013)
DAMA, 2000, NaI−0 to 4 combined, 58,000kg−days, 3sigma, SI
CoGeNT, 2013, WIMP region of interest, SI
DATA listed top to bottom on plot
HEP Pheno The Standard Model Beyond the SM
DM Detection
Direct Detection
ψ
φSM
φH
ψ
NN
WIMP Mass [GeV/c2]
Cro
ss−
sect
ion [
cm2]
(norm
alis
ed t
o n
ucl
eon)
131206083800
http://dmtools.brown.edu/ Gaitskell,Mandic,Filippini
101
102
103
10−50
10−48
10−46
10−44
10−42
10−40
10−38
Xenon10T, G3 expected sensitivity (2013)
LUX (2014/15) 300d projection (SI, 90% CL median expected)
LUX (2013) 85d 118kg (SI, 95% CL)
XENON100, 2012, 225 live days (7650 kg−days), SI
CRESST II commissioning run (2009) extended to low masses
CDMSII−Si (Silicon), c58 95% CL , SI (2013)
DAMA, 2000, NaI−0 to 4 combined, 58,000kg−days, 3sigma, SI
CoGeNT, 2013, WIMP region of interest, SI
DATA listed top to bottom on plot
HEP Pheno The Standard Model Beyond the SM
DM Detection
Hidden Sector Dark Matter at LHC
[SG, Lee, Wells:2009]
100 200 300 400 500 600 700
0.5
1.0
1.5
2.0
2.5
3.0
MΨ HGeVL
Κ 11
WDM =0.3
0.2
0.1
100 200 300 400 500
0.0
0.2
0.4
0.6
0.8
1.0
mh HGeVL
BR
WW
bb
ΨΨ
ZZ
tt
Look for LHC signal in pp → jj + /ET
HEP Pheno The Standard Model Beyond the SM
DM Detection
Neutrino Mass Generation
HEP Pheno The Standard Model Beyond the SM
DM Detection
Neutrino Mass Generation
Questions
What is the scale of mν
Is the ν a DIRAC or MAJORANA particle? (Is L# good?)
Which mass spectrum?
m
m m
m
m
m
m
1
1
2
32
3
1,2,3
NORMAL INVERTED DEGENERATE
Is there CP violation in the lepton sector?
Possible Answers
Dirac ν : Add νR with TINY (10−12) Yukawa coupling
Type I seesaw: Add νR and a BIG (1011 GeV) mass
Type II seesaw: Add SU(2) triplet scalar ξ with TINY (0.1 eV) VEV
Type III seesaw: Add SU(2) triplet fermion Ξ
Extra dimensions: Add BULK νR with BRANE coupling to νL
HEP Pheno The Standard Model Beyond the SM
DM Detection
Neutrino Mass Generation
Questions
What is the scale of mν
Is the ν a DIRAC or MAJORANA particle? (Is L# good?)
Which mass spectrum?
m
m m
m
m
m
m
1
1
2
32
3
1,2,3
NORMAL INVERTED DEGENERATE
Is there CP violation in the lepton sector?
Possible Answers
Dirac ν : Add νR with TINY (10−12) Yukawa coupling
Type I seesaw: Add νR and a BIG (1011 GeV) mass
Type II seesaw: Add SU(2) triplet scalar ξ with TINY (0.1 eV) VEV
Type III seesaw: Add SU(2) triplet fermion Ξ
Extra dimensions: Add BULK νR with BRANE coupling to νL
HEP Pheno The Standard Model Beyond the SM
Conclusions
Conclusions
Standard Model has shortcomings
Observational: DM, BAU, ν massTheoretical: Gauge (& flavor) hierarchy problem
Beyond the Standard Model physics to resolve these
Supersymmetry, Extra dimension(s), Strong dynamics, Little Higgs, ...
Which (if any) of these realized in Nature?
Desperately seeking experimental guidanceExperiments poised for discovery?
LHC7,8 constraints already nontrivial.LHC14 high luminosity run crucialDM Direct, Indirect, Collider detectionFlavor and precision probes (Belle)
BACKUP SLIDES
BACKUP SLIDES
MSSM fields
To every SM particle, add a superpartner (spin differs by 1/2)
Matter fields (Chiral Superfields)
(SU(3), SU(2))U(1) Components
Q (3, 2)1/6 (qL, qL, FQ ) ; qL =
(uLdL
); qL =
(uLdL
)Uc (3, 1)−2/3 (u∗R , u
cR , FU )
Dc (3, 1)1/3 (d∗R , dcR , FD )
L (1, 2)−1/2 ( ˜L, `L, FL) ; ˜
L =
(νLeL
); `L =
(νLeL
)Ec (1, 1)1 (e∗R , e
cR , FE )
(Nc ) (1, 1)0 (ν∗R , νcR , FN )
Gauge fields(Vector Superfields)
Components
SU(3) (gµ, g,D3)
SU(2) (Wµ, W ,D2)
U(1) (Bµ, B,D1)
Higgs fields (Chiral Superfields)
(SU(3), SU(2))U(1) Components
Hu (1, 2)1/2 (hu , hu , FHu ) ; hu =
(h+uh0u
); hu =
(h+uh0u
)Hd (1, 2)−1/2 (hd , hd , FHd
) ; hd =
(h0d
h−d
); hd =
(h0d
h−d
)
AdS/CFT Correspondence
AdS/CFT Correspondence [Maldacena, 1997]
A classical supergravity theory in AdS5 × S5 at weak coupling is dual to a4D large-N CFT at strong coupling
The CFT is at the boundary of AdS [Witten 1998; Gubser, Klebanov, Polyakov 1998]
ZCFT [φ0] = e−ΓAdS [φ0]
S ⊃∫
d4x OCFT (x)φ0(x)
Eg: 〈O(x1)O(x2)〉 = δ2ZCFT [φ0]δφ0(x1)δ(x2)
with ZCFT given by the RHS
ΓAdS [φ] supergravity eff. action
φ(y , x) is a solution of the EOM (δΓ = 0)
for given bndry value φ0(x) = φ(y = y0, x)
4D Duals of Warped Models
[Arkani-Hamed, Porrati, Randall, 2000; Rattazzi, Zaffaroni, 2001]
Dual of Randall-Sundrum model RS1 (SM on IR Brane)
Planck brane =⇒ UV Cutoff; Dynamical gravity in the 4D CFTTeV (IR) brane =⇒ IR Cutoff; Conformal invariance broken below a TeV
All SM fields are composites of the CFT
Dual of Warped Models with Bulk SM
UV localized fields are elementaryIR localized fields (Higgs) are composite
4D dual is Composite Higgs model [Georgi, Kaplan 1984]Shares many features with Walking Extended Technicolor
Partial Compositeness
AdS dual is weakly coupled and hence calculable!
KK states are dual to composite resonances
U(1)X Hidden sector
Coupled to SM (us) via the Higgs [SG, Jung, Lee, Wells:2008, 2009]
Accidental Z2 symmetry : ψ → −ψ , SM → SM
So ψ cosmologically stable =⇒ Dark Matter
Bµ Xµ
φSM φH
ψSM
Direct Detection? Hidden sector signature at the LHC?
Particle Physics and the Universe
Evidence for Dark Matter (DM)
No Big Bang
1 2 0 1 2 3
expands forever
-1
0
1
2
3
2
3
closed
recollapses eventually
Supernovae
CMB
Clusters
open
flat
Knop et al. (2003)Spergel et al. (2003)Allen et al. (2002)
Supernova Cosmology Project
Ω
ΩΛ
M
Bullet Cluster [Hubble+Chandra, NASA, ESA, CXC, M. Bradac (UCSB), and S. Allen (Stanford)]
Ω0 = 0.222± 0.02 [PDG ’08]
DM at Colliders II
Example: Supersymmetry
tR , bR , g
(Yt)
`+
bL
(YN)
Hu
tR
NR
(Yb)
`+
tL
NR
Hd
(YN)
X
Hu
bR
LSP leads to “missing momentum”
Explaining SM (gauge & mass) hierarchies (WED)
Bulk Fermions explain SM mass hierarchy [Gherghetta, Pomarol 00][Grossman, Neubert 00]
S(5) ⊃∫d4x dy
cψ k Ψ(x, y) Ψ(x, y)
Fermion bulk mass (cψ parameter) controls f ψ(y) localization
h
q
χ Rt
3
f
f
0
1
RS-GIM keeps FCNC under control
For details, see our review: [Davoudiasl, SG, Ponton, Santiago, New
J.Phys.12:075011,2010. arXiv:0908.1968 [hep-ph]]
CMS Resonances Limits (Moriond 2013)