Transcript Slide 1

Metastable Vacua and D-branes at the Conifold
Sebastián Franco
Princeton University
September 2007
Based on: hep-th/0610212: Argurio, Bertolini, Franco and Kachru
hep-th/0703236: Argurio, Bertolini, Franco and Kachru
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Meta-stable SUSY breaking in field theory and string theory
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SU(Nc) SQCD with massive flavors
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The model
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A mass term from a stringy instanton
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Stabilization of dynamical masses
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Gravity dual
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Type IIA T-dual
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Dynamical SUSY breaking (DSB) may be relevant in the description of
Nature at the electroweak scale.
Meta-stable SUSY breaking
 Quite generic in field theory.
 Crucial in some string theory constructions.
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DSB is often a strong coupling phenomenon. Two powerful tools:
 Seiberg duality.
 Gauge/gravity duality.
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Gauge/gravity
duality:
Kachru, Pearson and
Verlinde (KPV)
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Smooth gravity dual of the cascading SU(N+M) x SU(N)
Klebanov and Strassler
conifold theory .
Add p « M anti-D3 branes. They are attracted to the tip.
Non-SUSY meta-stable states in the SU(N+M-p) x SU(N-p)
at large ‘t Hooft coupling.
These states are important in KKLT and models of inflation
in string theory.
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Seiberg duality:
Intriligator, Seiberg
and Shih (ISS)
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Meta-stable SUSY breaking vacuum in field theories as
simple as SQCD with light massive flavors.
SUSY breaking vacuum occurs at strong coupling and small
vevs.
Seiberg duality
Qualitative similarities between KPV and ISS states:
 Related to baryonic branch (for Nf = Nc).
 Non-chiral gauge theories.
 Moduli space of Goldstone modes.
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It is natural to expect that SUSY breaking at the end of a warped throat is
AdS/CFT dual to dynamical SUSY breaking.
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Is there some relation between the two classes of meta-stable states?
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In this talk, we will argue that in some cases the answer is yes.
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Intriligator, Seiberg and Shih (ISS)
Requirements:
1 - SUSY breaking
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rank-condition mechanism
2 - In a metastable minimum
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pseudomoduli become massive at 1-loop
3 - That is parametrically long-lived
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distance between non-SUSY and SUSY minima
height of the barrier
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Computational requirement:
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Nf in the free magnetic range
V
Vp
V+
0 
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SU(Nc) SYM with Nf massive flavors Q and Q
m << LSQCD
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In order to have control in the IR: theory in the free-magnetic range
Nc + 1 ≤ Nf < 3/2 Nc
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To study the IR behavior we use the IR free Seiberg dual description
Gauge group: SU(N) with N = Nf - Nc
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Matter content:
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Dual quarks: q
Mesons:
 = QQ
SUSY is broken at tree level. F-term for :
This is the rank-condition mechanism
q
rank Nf
rank N < Nf
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There is a classical moduli space of SUSY breaking vacua with
All pseudomuduli (classically flat directions not corresponding to Goldstone
directions) become massive due to the one-loop effective potential:
The point of maximal unbroken global symmetry is a meta-stable SUSY
breaking minimum
(a)
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The theory has Nf - Nc SUSY minima at:
(b)
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The distance in field space and the potential barrier between (a) and (b)
guarantee that the SUSY breaking minimum (a) is parametrically long-lived
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CY3
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We engineer our gauge theory in string theory by
considering (fractional) D3-branes at the tip of a
Zn orbifold of the conifold.
D3
D5
Z3 orbifold
NZ1n orbifoldN2
1
2
r1
r2
1
2
2N gauge groups and
4N bifundamentals
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N6 6
3
5
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N5
N4
N3
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Both the conifold and its orbifold are non-chiral. The ranks can be arbitrary.
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Anomaly free rank assignments
Regular and fractional branes
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We want to consider ranks: (Nc, Nc, Nc,1,0,0)
1
2
3
4
Nc
Nc
Nc
1
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Fractional branes can be classified according to the
IR dynamics of the gauge theories on them
Fractional branes
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Deformation
N=2
DSB
Franco, Hanany,
Saad and Uranga
Singularities are not isolated
Obstructed deformation
(1,1,0,0,0,0): N=2 fractional branes
(0,0,1,0,0,0): deformation fractional branes
(0,0,0,1,0,0): deformation fractional brane
This theory arises at the IR bottom of a duality cascade
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1
2
3
4
Nc
Nc
Nc
1
h L12 << m
stringy instanton
Node 1 has Nc = Nf
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quantum moduli space
We obtain the ISS model with Nf = Nc + 1 massive flavors
deformed by a quartic superpotential
Kitano, Ooguri and Ookouchi
Using Seiberg duality, we can see that there is a metastable SUSY-breaking
vacuum with:
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To find the metastable vacuum
use magnetic dual
1
2
3
4
Nc
Nc
1
1
 Seiberg mesons: fij = Xi3 X3j
 Magnetic quarks: Yi3 and Y3j
 Mesons and baryons of confinig node 1: M22 = X21 X12
B and B
The pseudomodulus f22 gets a non zero vev
f22 ~ h L32 at 1-loop
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Where does
come from?
D-brane instantons wrapping cycles corresponding to quiver nodes which are
can contribute corrections to W
not occupied by space-filling branes.
Consider an ED1 wrapping node 5 of the quiver. Acting on the instanton with
the broken supercharges then produces two fermion zero modes in the ED1 ED1 sector.
Extended quiver:
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b
3
4
Nc
1
a
5
With a and b fermionic zero modes.
Bosons arise in the NS sector, but contributions from ND directions push the
vacuum energy above zero.
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A similar ED1 wrapping node 6 generates:
Quantum constraint on node 1:
<M22>
What prevents the baryons from condensing, relaxing the vacuum energy to 0?
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Actually, the leading off-diagonal term in the mass matrix for fluctuations is:
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The potential contains the following terms:
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instanton
< f22>
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Baryonic directions are stable provided that:
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The Z3 orbifold of the conifold we are studying is described by:
It is a toric singularity:
(0,1)
(1,0)
(-1,0)
(-1,0)
(1,0)
(1,0)
(-1,0)
(0,1)
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It admits three independent complex deformations:
Three non-trivial compact
3-cycles Ai
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Consider two of the 3-cycles are blown-up to the same size:
A1 singularity:
C2/Z2 × C
conifold
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After a geometric transition, the Nc deformation branes on node 3 turn into flux:
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steps in the
cascade
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The Nc N=2 D5-branes wrapping C2/Z2 are explicitly present in the dual, at some
point along C (the complex dimension parametrizing the mesonic branch).
The single brane on node 4 remains as a probe.
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Non-SUSY states of a field theory can be obtained by adding anti-D3 branes
to the dual confining geometry. Kachru, Pearson and Verlinde
If the brane charges at infinity are kept fixed, these states are interpreted
as vacuum states of the same gauge theory (at strong ’t Hooft coupling).
For the quiver we are studying, the gravity dual has N = k Nc units of D3brane charge.
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add anti-D3
add D3
perturbatively annihilate
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The same happens for 2,…, Nc -1 anti-D3’s.
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But we can add Nc anti-D3 brane probes and “jump fluxes”:
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The mesonic branch also contains Nc D5 probes, around small cycles in the
curve of A1 singularities.
The fractional brane charges are aligned with the D3 charges. The D5s attract
the Nc anti-D3s. The anti-D3s dissolve in the D5s as gauge flux:
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It is impossible to get meta-stable states for 1,…, Nc -1 anti-D3 branes.
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The energy of the SUSY breaking vacuum is ~ Nc in units of the dynamical scale.
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Even though the number of anti-D3s is comparable to the RR flux.
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For large Nc the 3-form fluxes are diluted and the gradient of the Myers potential
that would make the branes polarize into 5-branes is small.
This effect is overcome by the D5 / anti-D3 attraction.
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There is a simple Type IIA, T-dual Hanany-Witten configuration. It provides a
very intuitive picture of how the anti-branes appear.
4,5
N1
N2
N3
NS’
NS’
NS
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N4
NS
N5
N6
6
8,9
NS’
NS
Let us consider fractional branes leading to the (Nc,Nc,Nc,1,0,0) quiver.
Starting from the case with <M22> = m = 0.
Nc
Nc
NS’
NS
Nc
1
NS’
NS
electric
Nc
NS’
NS
Nc
NS’
SD
NS
N1c
1
NS’
NS
NS’
NS
magnetic
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C2/Z2 × C
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Electric configuration
<M22>
Nc
Seiberg duality
Nc
m
1
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Nc
<M22>
Magnetic configuration
Nc
m
1
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explicit anti-branes due to
failure to overlap
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Final configuration
<M22>
Nc
m
1
T-dual to anti-D3’s dissolving into D5’s as gauge flux
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We have engineered a gauge theory with interesting features using Dbranes on a Calabi-Yau singularity.
At weak 't Hooft coupling we have argued using field theory techniques that
it admits both supersymmetric and meta-stable non-supersymmetric vacua.
All the dimensionful parameters are dynamically generated.
We have proposed a gravity description for both sets of vacua at strong 't
Hooft coupling.
Our work indicates that, at least in some cases, the meta-stable states
constructed using anti-D branes in warped throats are related to ISS-like
states.
String instanton effects play an important role.
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Orbifolds of the conifold provide a simple case in which stringy instantons
can be understood as arising from a duality cascade. Aharony and Kachru
They are flexible enough to engineer standard SUSY breaking models
Aharony, Kachru and Silverstein
without non-abelian gauge dynamics.
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Embedding in a Calabi-Yau compactification.
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Understand gravity dual in more detail.
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Can we find meta-stability in gravity duals of “simpler” field theories. Do
they suggest other mechanisms ? Other regimes?
Franco, Rodriguez-Gomez and Verlinde (in progress)
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