Unification Hints The Standard Model: Partial Unification.
-
Upload
loreen-shelton -
Category
Documents
-
view
236 -
download
3
Transcript of Unification Hints The Standard Model: Partial Unification.
Matter Sector “chiral”
L
u
d
L
u
d
L
u
d
RuRu
Ru
(3)SU
Family Symmetry?
(2)SU
Neutral
Up
Down
(2)SU
Family Symmetry?
e
Le
ReL
RL
R
L
c
s
L
c
s
L
c
s
L
t
b
L
t
b
L
t
b
RdRd
Rd Rc
RcRc Rs
RsRs
RtRt
Rt Rb
Rb
Rb
Ru cLu
Standard Model parameters
1 2 3, ,g g g 1
2
tan W
g
g
, , , ,i i iZ H u d lM M m m m
1 2 3, , , 5(1 ) CKM
d
W u c t U s
b
Cabibbo, Kobayashi, Maskawa
QCD
-ucuc u duc u d
u dec
} (3)SU
} (2)SU?3 0
eQ Q
dc
dc
dcee
5 :L
10 :L
1/ 3cdQ
Grand Unification (5) (3) (2) (1)SU SU SU U (10)SO
(10(16 ) 1) ) (5 ( )L LL L , ,
ce L e R
LH states SU(2) doublets
{
-ucuc u duc u d
u dec
} (3)SU
} (2)SU
dc
dc
dcee
5 :L
10 :L
Grand Unification (5) (3) (2) (1)SU SU SU U (10)SO
(10(16 ) 1) ) (5 ( )L LL L
-tctc t btc t b
t bc
bc
bc
bc
-ucuc u ducu d
u dec
-ucuc u ducu d
u dec
dc
dc
dc
ee
-cccc c sccc s
c sc
sc
sc
sc
Generations (?)
-ucuc u duc u d
u dec
dc
dc
dcee
5 :L
10 :L
Grand Unification (5) (3) (2) (1)SU SU SU U
} : New lepto-quark gauge interactionsX
XM
} u
u
dc
e+X
4XM 32 1610 yrs, 10XM GeV
0p e
-ucuc u duc u d
u dec
} (3)SU
} (2)SU
dc
dc
dcee
5 :L
10 :L
Gauge Couplings (5) (3) (2) (1)SU SU SU U
5 3 2 1g g g g
1 2 3 5( ) ( ) ( )X X XM M Mg g g g
XM
2 2
1 1ln
( ) ( )X
ii Z i X Z
Mb
g M g M M
q
q
g
g
g
g+
P
r eci
sio
n M
easu
rem
ets
30
60
50
40
20
10
0
Log 10 [Energy Scale (GeV)]3 5 7 9 11 13 15 17
1-1
2-1
3-1
Either: No Grand Unificationor: more particles...
Either: No Grand Unificationor: more particles...
Sup
ersy
mm
etry
thre
shol
d
Log 10 [Energy Scale (GeV)]3 5 7 9 11 13 15 17
1-1
2-1
3-1
TeV scale supersymmetry
2sin 0.2337 0.0015W . 0.2312 0.0002c f Expt
String theory
World sheet
( , )X
1( , )
4 'FreeS d d h h X X
}
String tension
Elementary particles string excitations
Open Closed
String Structure : 1st string revolution
Ghost free condition :
D=10 Fermionic (+SUSY)E8
SO(32)
Type I
Type IIA
Type IIB
String excitations :2
'string
Jm C
J
m2Compactification
D=10 D=4 +(D=6)compactified – radius R
Kaluza Klein & winding modes '
n Rm p
R
Gauge structure : restricted by anomaly cancellation Green Schwarz
8 8 8 6†. . ( 10) ( 4) ( 1 )e g E E D E E D N SUSY
6 (10), (5) (3) (2) (1)E SO SU SU SU U +chiral structure for q, l ; multiplet structure determined by topologyof manifold : Calabi Yau - 3 generation examples known
Supersymmetry
(c.f. D=26 Bosonic)†
String Structure : 2nd string revolution
E8
SO(32)
Type I
Type IIA
Type IIB
D=11 supergravity
M
String dualities
'. .e g R
R
Kaluza Klein winding modes'
n Rm p
R
n p
D-branes
Submanifold on which open strings start or end
String phenomenology
Can obtain gauge and multiplet st
ru
cture + underlying
e.g. het
GUT stru
erotic st
ctu
re
ring
Wilson line breaking at the compactification scale can elegantly
solve the doublet triplet splitting pro
blem
u d (3) (2) (1) + 3(10+5 1) + H + H (MSSM) SU SU U
Many other possibilities - not necessarily with GUT structure -
possibly with a low scale of unificati
on
How can we distinguish them?
Sup
ersy
mm
etry
thre
shol
d
Log 10 [Energy Scale (GeV)]3 5 7 9 11 13 15 17
1-1
2-1
3-1
TeV scale supersymmetry
2sin 0.2337 0.0015W . 0.2312 0.0002c f Expt
I
GGR, D.Ghilencea
SUSY gauge coupling unification
2sin 0.2334 0.0025 0.25( 0.119)W s 0.2311 0.0007 ( )Expt
2sin 0.2311 0.0007W
20.134 0.01 4(sin 0.2334)s W 0.119 0.01 ( )Expt
I
Unification Hints
× 3,2,1
E10-60
TeV MPla
nck
Gravitationalcoupling
1/r2+n
1/rp Gauge coupling
?
Unification at a TeV?
Warped Unification
2 2 2 , 0kyds e dx dx dy y R
RS1
( ) RH PlanckM R e M TeV Brane
All scales up to Planck scale present - logarithmic running of gauge couplings!
Randall, SchwarzSundrum, Delgardo,...
Choi, Kim, Kim
×
D=5
1ga
2 aM R 1
8 2 a O 1
8 2,
a ba lnM /k ba
lnkR ba ln1/MKKR ba lnMKK/
I
2sin 0.2334 0.0025 0.25( 0.119)W s 0.2311 0.0007 ( )Expt
2sin 0.2312 0.0007W
20.134 0.01 4(sin 0.2334)s W 0.119 0.01 ( )Expt
16(3.5 2).10UM GeV
Updated fit :
E10-60
MP
3,2,1
GN(Q) Q2
Unification with gravity?
SUSY coupling unification
10 24 3
4( ...)
' 'HSeff i
iL d x ge R Trk
F
2' 1/ only scalestringM 110
}
4d xV
}
4 310 10
'' ',
64 16 4String
N String NG GV V
2 2
1ln
( )string
i ii Z s
i
tring Z
Mb
g M g
k
M
17. 3.6 10string string PlanckM g M GeV
Gauge unification - Heterotic String
....close...but not close enough!
16. . (3.5 2).10Uc f M GeV
1 2
2
14
itorui s
d db Z
1 2 1 2
221 1 2 2 2 1 1 2
2 2
2 ( )torusn m Z
Z exp i m n m n exp TUn Tn Um mTU
1 2 ,T R R 1 2U R R
String Threshold Effects (WCHS) 6 ,T G 6 2 4T T T
N=2
2 1{ 0 1 2 1}
KK modesWinding modes
4
2 22 41
3 3ln 4 ( )
4 2i
i s s
ib i M R M Re
12 2
1( ) 1 ,iT ikT
kT e e
2 ( ),T iR U i
Dixon,Kaplunovsky,Louis
2 large i R R
Threshold sensitivity
1/ cx RM
1cRM
2cRM
To preserve insensitivity to heavy thresholds (no power law sensitivity) need 2cRM
...but still have to bring into agreement with experiment?UM
Ghilencea,GGR
Weakly coupled heterotic strings with Wilson line breaking
1I Iym
ii dyA T
iW e I rank G i
/M M D
Discrete group D G
( ) ( )x dx Physical states :
2 2 2 3 3 2 /( ), , i NND Diagonal a a a a a D Z a e e.g.
(5) (3) (2) (1) ( are singlets - X,Y bosons massive)aSU SU SU U A D
2
2 2
111
" " ( 3, complete reps)D D DD DD D
R R R R R N q l
111
(Higgs split reps - doublet triplet splitting)DDD
R R
/( )diagonalM D D
( ) ( )iW x dx
, (5
2)
2log( ) log( )( ) (
l ()
4 4og )
X Y SUi im m m
(3) (2) 1)) ((5S SUU SU U
2 2 22
1( ) ( )nM n
R 1n
0n
.
.
.
Reduction in X,Y boson contribution -equivalent to reduction in unification scale.
,X Y
3,2,1 }
(14)
3,2,1
22
5241 12 2 2 2 2 2
sinsin (5 )(3 2 1)2( ) log ln 2 ln
2 3 4 4jX Y i ji i
i GUTHiggs jX s s
bb bQQ
M M R M R
1 log2 2
i iGUT
X
b bQ
M
N=3, n=1 N=7, n=1 N=7, n=2 N=7, n=3
3.64 (4.12) 3.68 (4.43) 3.71 (3.78)) 4.81 (6.75)
-0.25 (-0.27) -0.25 (-0.28) -0.25 (-0.25) -0.30 (-0.36)
2.81 (3.10) 2.84 (3.29) 2.86 (2.90) 3.50 (4.61)
0.49 (0.54) 0.50 (0.57) 0.50 (0.51) 0.60 (0.73)
Quantitative effect of Wilson lines :
2sM R
No Higgs KK modes
Higgs KK modes
2D 1D or 2D (matter KK modes degenerate)GGR
0X
X
MM
13
0X
X
MM
3
1 2 2 0
-13 . . 1.04 expc f t
nD Z
0
. . =10 expX
X
MMc f t
String profile from gauge unification
Bring into agreement with experimentXM prediction
Preserve accuracy of prediction (insensitivity to
unknown thresholds)
s Improve prediction
20.122 0.01 4(sin 0.2334)s W . . 0.119 0.003(?)c f
11 66 . . (2.5 2).10 7 10s c f eM GeV G V
2, larges sM R M
WCHS + Wilson line ( 2, N=7) sM R
WCHS + Wilson line ( 2, N=7) sM R
†† 15U 11 s(c.f SCHS ... can fit M with R 10 but unchanged)GeV