NonSUSY Physics Beyond the Standard Model. J. Hewett, PreSUSY 2010. Why New Physics @ the Terascale?. Electroweak Symmetry breaks at energies ~ 1 TeV (SM Higgs or ???) WW Scattering unitarized at energies ~ 1 TeV (SM Higgs or ???)
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
energies ~ 1 TeV (SM Higgs or ???)
New Physics ~ 1 TeV
All things point to the Terascale!
Brief review of features which guide & restrict BSM physics
SGauge = d4x FY FY + F F + Fa Fa
SFermions = d4x fDf
SHiggs = d4x (DH)†(DH) – m2H2 + H4
SYukawa = d4x YuQucH + YdQdcH† + YeLecH†
( SGravity = d4x g [MPl2 R + CC4] )
Generations
f = Q,u,d,
L,e
SM predictions @ 2+ loop level
Jet production rates @
Tevatron agree with QCD
Standard Model predictions well described by data!
Pull
Q1
u1
d1
L1
e1
.
. 2
.
. 3
Rotate 45 fermions into each other
U(45)
SM matter secretly has a large symmetry:
Explicitly broken by gauging 3x2x1
Rotate among generations
U(3)Q x U(3)u x U(3)d x U(3)L x U(3)e
Explicitly broken by quark Yukawas + CKM
Explicitly broken by charged lepton Yukawas
U(1)e x U(1) x U(1)
Explicitly broken by neutrino masses
U(1)B
Baryon Number
Lepton Number
U(1)L (Dirac)
(or nothing) (Majorana)
1 + i2
3 + i4
Four real degrees of freedom
Higgs Doublet:
Secretly transforms as a
1
2
3
4
4 of SO(4)
Decomposes into
subgroups
(2,2) SU(2) x SU(2)
SU(2)L of EW
Leftover Global Symmetry
1 + i2
3 + i4
Four real degrees of freedom
Higgs Doublet:
Secretly transforms as a
Gauging U(1)Y explicitly breaks
Size of this breaking given by Hypercharge coupling g’
1
2
3
4
SU(2)Global Nothing
4 of SO(4)
Decomposes into
subgroups
MW2 g2
= 1 as g’0
MZ2 g2 + (g’)2
(2,2) SU(2) x SU(2)
New Physics may excessively break SU(2)Global
SU(2)L of EW
Remaining Global Symmetry
Custodial Symmetry

Fermions cannot simply ‘pair up’ to form mass terms
i.e., mfLfR is forbidden Try it!
(Quc) 1 2 1/2
(Qdc) 1 2 +1/2
(QL) 3 1 1/3
(Qe) 3 2 +7/6
(ucdc) 3x3 1 1/3
(ucL) 3 2 7/6
(uce) 3 1 +1/3
(dcL) 3 2 5/6
(dce) 3 1 +4/3
(Le) 1 2 +1/2
SU(3)C SU(2)L U(1)Y
Fermion masses must be generated by Dimension4 (Higgs) or higher operators to respect SM gauge invariance!






An anomaly leads to a mass for a gauge boson
Anomaly Cancellation
Quantum violation of current conservation
SU(3)
SU(3)
SU(2)L
SU(2)L
U(1)Y
U(1)Y
g
g
3[ 2‧(1/6) – (2/3) + (1/3)] = 0
Q uc dc
U(1)Y
U(1)Y
U(1)Y
U(1)Y
3[3‧(1/6) – (1/2)] = 0
Q L
3[ 6‧(1/6)3 + 3‧(2/3)3 + 3‧(1/3)3
+ 2‧(1/2)3 + 13] = 0
3[(1/6) – (2/3) + (1/3) – (1/2) +1]
= 0
Q uc dc L e
Can’t add any new fermion must be chiral or vectorlike!
SU(3)C x SU(2)L x U(1)Y
Exact
Broken to U(1)QED
U(3)5 U(1)B x U(1)L (?)
Explicitly broken by Yukawas
SU(2)Custodial of Higgs sector
Broken by hypercharge so = 1
Need Higgs or Higher order operators
Restrict quantum numbers of new fermions
SU(3)C x SU(2)L x U(1)Y
Exact
Broken to U(1)QED
U(3)5 U(1)B x U(1)L (?)
Explicitly broken by Yukawas
SU(2)Custodial of Higgs sector
Broken by hypercharge so = 1
Need Higgs or Higher order operators
Restrict quantum numbers of new fermions
Any model with New Physics must respect these symmetries
An effective field theory has a finite range of applicability in energy:
, Cutoff scale
Energy
SM is valid
Particle masses
All interactions consistent with gauge symmetries are permitted, including higher dimensional operators whose mass dimension is compensated by powers of
Precision Electroweak
Generic Operators
Flavor Violation
CP Violation
Baryon Number Violation
Contact Operators
Constraints on Higher Dimensional Operators
Λ≳ 1016 GeV
Λ≳ 1015 GeV
Λ≳ 106 GeV
Λ≳ 106 GeV
Λ≳ 103 GeV
Λ≳ 103 GeV
Λ≳ 3x102 GeV
New Physics, Beyond the Standard Model!
Three paradigms:
New physics introduced to explain
Technically Natural
(Yukawa Couplings)
Logarithmically
sensitive to the cutoff
scale
The Higgs (mass)2 problem
or
The hierarchy problem
Energy (GeV)
1019
Planck
1016
GUT
desert
Future Collider Energies
103
Weak
All of known physics
Solar System
Gravity
1018
Energy (GeV)
1019
Planck
Quantum Corrections:
Virtual Effects drag
Weak Scale to MPl
1016
GUT
desert
Future Collider Energies
mH2 ~
~ MPl2
103
Weak
All of known physics
Solar System
Gravity
1018
a classic!
aged to perfection
better drink now
mature, balanced, well
developed  the Wino’s choice
’67 The Standard Model
’77 Vin de Technicolor
’70’s Supersymmetry: MSSM
’90’s SUSY Beyond MSSM
’90’s CP Violating Higgs
’98 Extra Dimensions
’02 Little Higgs
’03 Fat Higgs
’03 Higgsless
’04 Split Supersymmetry
’05 Twin Higgs
svinters blend
all upfront, no finish
lacks symmetry
bold, peppery, spicy
uncertain terrior
complex structure
young, still tannic
needs to develop
sleeper of the vintage
what a surprise!
finelytuned
double the taste
J. Hewett
Anything Goes!
(We stilll have a bit more time)
Most cases controlled by
Parton flux
Supermodel Discovery Criteria:
Solid: 7 TeV vs Tevatron
Dashed: 10 TeV vs Tevatron
Bauer etal 0909.5213
Most cases controlled by
Parton flux
Supermodel Discovery Criteria:
Naive, but a reasonable guide
Solid: 7 TeV vs Tevatron
Dashed: 10 TeV vs Tevatron
Bauer etal 0909.5213


Current Tevatron bound
On 4th generation T’ quark:
~ 335 GeV (4.6 fb1)
Tevatron
exclusion
LHC7 should cover entire
4th generation expected
region!
Bauer etal 0909.5213
2dimensional shadow of a rotating cube
3dimensional shadow of a rotating hypercube
for us to observe they are
‘curled up’ and compact
The tightrope walker only sees one dimension: back & forth.
The ants see two dimensions: back & forth and around the circle
Every point in spacetime has curled up extra dimensions associated with it
One extra dimensionis a circle
Two extra dimensions can be represented by a sphere
Six extra dimensions can be represented by a CalabiYau space
E2 = (pxc)2 + (pyc)2 + (pzc)2 + (pextrac)2 + (mc2)2
In 4 dimensions, looks like a mass!
Recall pextra = n/R
Tower of massive particles
Small radius
Large radius
E2 = (pxc)2 + (pyc)2 + (pzc)2 + (pextrac)2 + (mc2)2
In 4 dimensions, looks like a mass!
Recall pextra = n/R
Tower of massive particles
Large radius gives finely separated KaluzaKlein particles
Small radius gives well separated KaluzaKlein particles
Small radius
Large radius
Consider a massless particle, p2 =0, moving in flat 5d
Then p2 = 0 = pμpμ± p52
If the + sign is chosen, the extra dimension is timelike,
then in 4d we would interpret p52 as a tachyonic mass
term, leading to violations of causality
Thus extra dimensions are usually considered to be
spacelike
scalar scalar
4vector Aμ A, Φ
tensor Fμν E, B
scalar (scalar)n
vector AM (Aμ, A5)n
tensor hMN (hμν, hμ5, h55)n
KK towers
→
→
→
scalar scalar
4vector Aμ A, Φ
tensor Fμν E, B
scalar (δ scalars)n
vector AM (Aμ, Ai)ni
tensor hMN (hμν, hμi, hij)n
KK towers
1 tensor, δ 4vectors, ½ δ(δ+1) scalars
→
→
→
Signals evidence of extra dimensions
Determined by geometry of extra dimensions
Measured by experiment!
The physics of extra dimensions is the physics of the KK excitations
……
Extra dimensions can do everything SUSY can do!
Three ways we hope to see extra dimensions:
Energy (GeV)
1019
Planck
Simplest Model:
Large Extra Dimensions
1016
GUT
desert
Future Collider Energies
103
Weak – Quantum Gravity
= Fundamental scale in
4 + dimensions
MPl2 = (Volume) MD2+
Gravity propagates in
D = 3+1 + dimensions
All of known physics
Solar System
Gravity
1018
ArkaniHamed, Dimopoulos, Dvali, SLACPUB7801
Motivation: solve the hierarchy problem by removing it!
SM fields confined to 3brane
Gravity becomes strong in the bulk
Gauss’ Law: MPl2 = V MD2+ , V = Rc
MD = Fundamental scale in the bulk
~ TeV
Massless 0mode + KK states have indentical coupling to matter
Han, Lykken, Zhang; Giudice, Rattazzi, Wells
Giudice, Rattazzi, Wells
JLH
Search for 1) Deviations in SM processes
2) New processes! (gg ℓℓ)
Angular distributions reveal spin2 exchange
M
Gn are densely packed!
(s Rc) states are exchanged! (~1030 for =2 and s = 1 TeV)
Giudice, Ratazzi,Wells
Mirabelli,Perelstein,Peskin

directly
Parameterized by density of states:

Discovery reach for MD (TeV):
The 14 TeV LHC is seen
to have considerable search
reach for KK Graviton
production
Hinchliffe, Vacavant
Energy (GeV)
1019
Planck
Model II:
Warped Extra Dimensions
1016
GUT
strong curvature
desert
Future Collider Energies
103
Weak
wk = MPl ekr
All of known physics
Solar System
Gravity
1018
Area of each grid is equal
Field lines spread out
faster with more volume
Drop to bottom brane
Gravity appears weak on top brane!
Randall, Sundrum
Bulk = Slice of AdS5
5 = 24M53k2
k = curvature scale
Hierarchy is generated by exponential!
Naturally stablized via GoldbergerWise
Davoudiasl, JLH, Rizzo
Phenomenology governed by two parameters:
~ TeV
k/MPl≲ 0.1
5d curvature:
R5 = 20k2 < M52
Recall = MPlekr ~ TeV
Davoudiasl, JLH, Rizzo
Unequal spacing signals curved space
e+e →μ+μ
e+e+
LHC
pp → l+l
Different curves for k/MPl =0.01 – 1.0
LHC can cover entire allowed parameter space!!
Start with gauge fields in the bulk:
Davoudiasl, JLH, Rizzo
Pomarol
towards Planck brane
towards TeV brane
Precision EW Constraints
Collider Signals are more difficult
KK states must couple to gauge fields or topquark to
be produced at observable rates

gg Gn ZZ
gg gn tt
Agashe, Davoudiasl, Perez, Soni hepph/0701186
Lillie, Randall, Wang, hepph/0701164
Dimopoulos, Landsberg
Giddings, Thomas
Black Holes produced when s > MD
Classical Approximation: [space curvature << E]
E/2
b < Rs(E) BH forms
b
E/2
^
MBH ~ s
Geometric Considerations:
Naïve = FnRs2(E), details show this holds up to a
factor of a few
RS2/(2Rc)2
n = 2  20
finite Rc as Rs Rc
2. Quantum Gravity Effects
Higher curvature term
corrections
Critical point for
instabilities for n=5:
(Rs/Rc)2 ~ 0.1 @ LHC
n = 2  20
GaussBonnet term
n2≤ 1 in string models
Decay proceeds by thermal emission of Hawking radiation
Not very sensitive to BH rotation for n > 1
At fixed MBH, higher dimensional BH’s are hotter:
N ~ 1/T
higher dimensional BH’s emit fewer quanta, with each quanta having higher energy
Multiplicity for n = 2 to n = 6
Harris etal hepph/0411022
Particle multiplicity in decay:
= greybody factor
Contain energy & anglular emission information
Provide good discriminating power for value of n
Generated using modified CHARYBDIS linked to PYTHIA
with M* = 1 TeV
Exciting times are about to begin.
Be prepared for the unexpected!!
2001 solar eclipse as viewed from Africa
Most Likely Scenario @ LHC: