d-term dynamical susy breaking nobuhito maru · dynamical susy breaking(dsb) is most desirable to...
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D-term Dynamical SUSY Breaking
Nobuhito Maru (Keio University)
with H. Itoyama (Osaka City University)
Int. J. Mod. Phys. A27 (2012) 1250159
[arXiv: 1109.2276 [hep-ph]]
12/6/2012 SCGT2012@Nagoya University
Plan
l Introduction l Basic Idea l Gap equation l Some Comments on Phenomenological Application l Summary
Introduction
SUPERSYMMETRY
is one of the attractive scenarios
solving the hierarchy problem,
but it must be broken at low energy
Dynamical SUSY breaking(DSB) is most desirable to solve
the hierarchy problem
F-term DSB is induced by non-perturbative effects due to nonrenormalization theorem and well studied so far
D-term SUSY breaking is NOT affected by the nonrenormalization theorem
In principle, D-term DSB is possible, but no known explicit model as far as we know
Basic Idea
L = d 4θK Φa ,Φa ,V( ) + d 2θ Im 1
2τ ab Φa( )∫ W aαWα
b + d 2θW Φa( ) + h.c.∫⎡⎣ ⎤⎦∫
N=1 SUSY U(N) gauge theory with an adjoint chiral multiplet
Wαa = −iλα
a y( ) + δαβDa y( )− i
2σ µσ ν( )α
βFµνa y( )⎡
⎣⎢⎤⎦⎥θβ
Φa = φ a y( ) + 2θψ a y( ) +θθFa y( )
d 2θτ ab Φ( )W aαWαb∫ ⊃τ abc Φ( )ψ cλ aDb +τ abc Φ( )Fcλ aλ b
d 2θW Φ( )∫ ⊃ − 12∂a∂bW Φ( )ψ aψ b
τ abc ≡ ∂τ ab Φ( ) ∂φ c
Dirac mass term
Fermion masses Important
dim 5 operator
yµ = xµ + iθσ µθ
∂W(Φa)/∂Φa = 0 @tree level assumed
− 12
λ a ψ a( )0 − 2
4τ abcD
b
− 24
τ abcDb ∂ac∂cW
⎛
⎝
⎜⎜⎜⎜
⎞
⎠
⎟⎟⎟⎟
λ c
ψ c
⎛
⎝⎜⎞
⎠⎟+ h.c.
Fermion mass terms
MF ≡0 − 2
4τ 0aaD
0
− 24
τ 0aaD0 ∂ac∂aW
⎛
⎝
⎜⎜⎜⎜
⎞
⎠
⎟⎟⎟⎟
Mixed Majorana-Dirac type masses (<F>=0 assumed)
Mass matrix
Only U(1) part of D-term VEV is assumed
m± =12
∂a∂aW 1± 1+ 2 D∂a∂aW
⎛
⎝⎜⎞
⎠⎟
2⎡
⎣
⎢⎢
⎤
⎦
⎥⎥
D ≠ 0& ∂a∂aW ≠ 0if
Gaugino becomes massive by nonzero <D>
⇒ SUSY is broken
D ≡ − 24
τ 0aaD0
D0 = − 12 2
g00 τ 0cdψdλ c +τ 0cdψ
dλ c( )D-term equation of motion:
Dirac bilinear condensation
The value of <D> will be determined
by the gap equation
Gap equation
V1−loopD( ) = ma
4
a∑ c + 1
64π 2⎛⎝⎜
⎞⎠⎟ Δ
2 + ′ΛresΔ4
8⎧⎨⎩
− 132π 2 λ +( )4 logλ +( )2 + λ −( )4 logλ −( )2⎡⎣ ⎤⎦
⎫⎬⎭
1-loop effective potential for D-term
Tree level D-term pot. + 1-loop CW pot. + counter term (-Im Λ/2 ∫d2Θ WαWα)
ma ≡ ∂a∂aW , λ ±( ) ≡ 121± 1+ Δ2⎡⎣
⎤⎦, Δ ≡
τ 0aaD0
2ma
, ′Λres ≡ c + β + Λres +1
64π 2 ,
1ma
4
a∑
∂2V∂Δ( )2
Δ=0
= 2c, β ≡g00 ∂a∂aW
2
ma4 τ 0aa
2
a∑
, Λres ≡ImΛ( ) ∂a∂aW
22
ma4 τ 0aa
22
a∑
Gap equation
0 =∂V1−loop
D( )
∂Δ= Δ c + 1
64π 2 +′Λres
4Δ2⎡
⎣⎢
− 164π 2 1+ Δ2
λ +( )3 2 logλ +( )2 +1( )− λ −( )3 2 logλ −( )2 +1( ){ }⎤⎦⎥
5 10 15 20 25 30
!1.0
!0.5
0.5
1.0
Δ
c +1 64π2 = 1, ′Λres 8 = 0.001
Nontrivial solution!!
1!
∂V1-loop(D)
∂!
E = D2/2 ≧ 0 in SUSY
⇒ Trivial solution Δ=0 is NOT lifted
⇒ Our SUSY breaking vac. is a local min.
Δ=0 1 2 3 4 5
5
10
15V(φ)
φ !≠ 0
Metastability of our false vacuum <D> = 0 tree vacuum is not lifted
⇒ check if our vacuum <D> 0 is sufficiently long-lived ≠
Decay rate of the false vacuum
∝ exp −
Δφ 4
ΔV⎡
⎣⎢⎢
⎤
⎦⎥⎥≈ exp − Λ2
ma2
⎡
⎣⎢
⎤
⎦⎥1
1 2 3 4 5
5
10
15V(φ)
φ
Coleman & De Luccia(1980) Δφ
ΔV our vac.
Long-lived for ma<< Λ
ma: mass of Φ, Λ: cutoff scale
Some Comments on Phenomenological Application
Following the model of Fox, Nelson & Weiner (2002),
consider a N=2 gauge sector & N=1 matter sector in MSSM ↑ Chirality, Asymptotic freedom of QCD
Take the gauge group (U(1)’:hidden gauge group) U 1( )′ ×GSM
Dim 5 gauge kinetic term provides Dirac gaugino mass term
d 2θτ abc Φ( )ΦSM
c ′W αaWαSMb∫ ⇒τ abc Φ( ) ′D a ψ SM
c λSMb
Gaugino masses are generated at tree level
Once gaugino masses are generated at tree level,
sfermion masses are generated by RGE effects
Msf2 ≈
Ci R( )α i
πM λi
2 log ma2
M λi2
⎡
⎣⎢⎢
⎤
⎦⎥⎥
Sfermion masses @1-loop
Flavor blind ⇒ No SUSY flavor & CP problems
(i = SU(3)C, SU(2)L, U(1)Y)
Figure 2: Loop contributions to scalar masses. The new contribution from the purely scalar loopcancels the logarithmic divergence resulting from a gaugino mass alone.
for the masses involving this spurion. The only possible such counterterm is proportional to
(2.3), and gives!
d4!!2!
2m4
D
!2Q†Q. (2.10)
Since we have four powers of mD, we have to introduce another scale to make this dimen-
sionfully consistent. Since the only other scale is the cuto" !, this operator is suppressed
by !2, and, in the limit that ! ! ", must vanish. Consequently, we conclude all radiative
corrections to the scalar soft masses are finite.
While a gaugino mass (including a Dirac mass) would ordinarily result in a logarith-
mic divergence, here this is cancelled by the new contribution from the scalar loop. The
contribution to the scalar soft mass squared is given by
4g2i Ci(")
!
d4k
(2#)41
k2#
1
k2 # m2i
+m2
i
k2(k2 # $2i )
, (2.11)
where mi is the mass of the gaugino of the gauge group i, and $2 is the SUSY breaking mass
squared of the real component of ai. If the term in (2.9) is absent, then $ = 2mi. As expected,
this integral is finite, yielding the result
m2 =Ci(r)%im2
i
#log
"
$2
m2i
#
. (2.12)
Note that as $ approaches mi from above, these one loop contributions will vanish! If A has
a Majorana mass of M , then this formula generalizes
m2 =Ci(r)%im2
i
#
$
log
"
M2 + $2
m2i
#
#M
2#log
%
2# + M
2# # M
&
'
, (2.13)
where #2 = M2/4 + m2i .
These contributions, arising from gauge interactions, are positive and flavor blind as in
gauge and gaugino mediation, but there are two other remarkable features of this result.
6
Fox, Nelson & Weiner, JHEP08 (2002) 035
Summary l A new dynamical mechanism of DDSB proposed
l Shown a nontrivial solution of the gap eq. with nonzero <D> in a self-consistent Hartree-Fock approx.
● Our vacuum is metastable & can be made long-lived
● Phenomenological Application briefly discussed
Backup
δV = 0
⇒ F0 2+ m0
g00 ∂0g00F0 + 1
2D0 2
+ 2 g00 V1−loop = 0
D0 ≠ 0 ⇒ F0 ≠ 0
V = gab ∂aW ∂bW − 12gabD
aDb +V1−loop +Vc.t .
Effective potenital up to 1-loop
Stationary condition
This determines the value of nonvanishing <F>
Lmassholo( ) = − 1
2g0a,a F 0 ψ aψ a + i
4F0aa F0 λ aλ a
− 12
∂a∂aW ψ aψ a + 24
F0aa D0 ψ aλ a
Fermion masses
SU(N) part:
U(1) part:
NG fermion: admixture of and λ 0 ψ 0
Fermion masses are modified as follows
Once SUSY is broken, the next issue we should consider is
how to mediate its breaking to our world
SUSY SSM
SM gauge interaction loops
δ12d( )
LL≡mQ ,122
m2≤ 0.01
m100 GeV
⎛⎝⎜
⎞⎠⎟
SUSY breaking mediation mechanism reflects the pattern of sparticle spectrum,
which must satisfy severe constraints from experiments
ex. K0 − K 0 mixing
Gauge mediation is one of the attractive scenarios
Super-Higgs mechanism
e−1Lgravitino mass = −eK 2W †ψ µσ
µνψν +ψ µσµ − g
2Daλ
a + eK 2 i2DaW
†ψ a⎡⎣⎢
⎤⎦⎥+ h.c.
′ψ µ =ψ µ +i2e−K 2
W † σ µ − g2Daλ
a + eK 2 i2DaW
†ψ a⎡⎣⎢
⎤⎦⎥
e−1Lgravitino mass = −eK 2W † ′ψ µσ
µν ′ψν +i2eK 2
W † − g2Daλ
a + eK 2 i2DaW
†ψ a⎡⎣⎢
⎤⎦⎥
2
+ h.c.
If we couple our theory to supergravity, a super-Higgs mechanism works Gravitino mass
can be diagonalized by the following redefinition of the gravitino
m3 2 = e
K 2 WMP
2 ≈0≈ V e K 2
DaW2+ g
2
2Da 2
3MP2
Gravitino mass
LU N( ) = Im d 4θTrΦeV ∂F Φ( )∂Φ∫ + d 2θ 1
2∂2F Φ( )∂Φa ∂Φb WαaWα
b∫⎡
⎣⎢
⎤
⎦⎥
+ d 2θTr 2eΦ+m ∂F Φ( )∂Φ
⎡⎣⎢
⎤⎦⎥+ h.c.∫
⎛⎝⎜
⎞⎠⎟
N = 2→N = 1 ModelFujiwara, Itoyama & Sakaguchi (2005, 2006)
“Electric” & “Magnetic” FI terms
F Φ( ) :"prepotential" holomorphic function of Φ
Take the following N=2 SYM
λ a ψ a( )→ ψ a − λ a( )
N=2 theory can be obtained from N=1 theory by imposing SU(2)R invariance
δλ a
ψ a
⎛
⎝⎜⎞
⎠⎟= 2 N gab
0 eδb0 +mF0b
− eδb0 +mF0b 0
⎛
⎝⎜⎜
⎞
⎠⎟⎟
η1η2⎛⎝⎜
⎞⎠⎟
= 2 N gab 0e− e( )δb
0η1
⎛⎝⎜
⎞⎠⎟
SUSY transformation
0 = ∂V∂φ a = gbdFadeg
ec eδb0 +mF0b eδ c
0 +mF0c
=0
eδb
0 +mF0b = 0Vacuum condition chosen as (F=0) from
N=2 SUSY is partially broken to N=1
NG fermion: ψ
Λa±( ) = maλ
±( ), λ ±( ) ≡ 121± 1+ Δ2( )
ma ≡ 2Nm gaaF0aa , Δ2 ≡
D0( )24Nm2
In the present model, the gaugino masses are
Adjoint scalar mass
V(Aµ, λ), Φ(φ, ψ)
Mass
0
ma Φ(φ, ψ)
V(Aµ, λ)
N=2 → N=1