The unification of electro-weak and strong interactions in a non-supersymmetric model
based on Phys. Rev. D 93 (2016) 105030
R. Frezzotti a) M. Garofalo b) G.C. Rossi a)c)
a)
Dipartimento di Fisica - Università di Roma Tor Vergata, INFN - Sezione di Roma Tor Vergata
b)
Higgs Centre for Theoretical Physics, The University of Edinburgh
c)
Centro Fermi - Museo Storico della Fisica, Piazza del Viminale 1 - 00184 Roma, Italy
Plank-Valencia-2016
Unification fails in the Standard Model (SM)
It can be achieved including supersimmetry as in the Minimal Supersimmetryc Standard Model (MSSM)
[S. Dimopoulos, S. Raby and F. Wilczek,Phys. Rev. D 24 (1981) 1681]
[S. P. Martin, Adv. Ser. Direct. High Energy Phys. 21 (2010) 1]
Figure: The running of electro-weak and strong couplings in the SM (black dotted lines) and in the MSSM
R. Frezzotti M. Garofalo G.C. Rossi
Non-supersymmetric extension of the Standard Model (BSMM) → unification to a similar accuracy of the MSSM.
Inspired from the work [R. Frezzotti and G. C. Rossi, Phys. Rev. D 92 (2015) 5, 054505.] → conjecture of a non-perturbative mechanism for the mass generation m ∼ αΛ (R. Frezzotti talk, “ Mass hierarchy and naturalness from TeV scale strong dynamics”)
m top requires the inclusion of a new superstrong interaction SU(N T ) with Λ T ∼ O(few TeV) and Λ T > Λ QCD
Set of superstrong interacting particles Q T and L T subject
to SU(N T )
The lagrangian of the BSMM is
L
BSM M= L
gauge+ L
SMF+ L
scalar+ L
SS,
L
gauge= 1 4
F
BF
B+ F
WF
W+ F
AF
A+ F
GF
G, L
SMF=
ng
X
f=1
h
¯
q
Lf6D
BW Aq
Lf+ ¯ q
f uR6D
BAq
f uR+ ¯ q
Rf d6D
BAq
Rf d+
+¯ `
fL6D
BW`
fL+ ¯ `
f uR6D
B`
f uR+ ¯ `
f dR6D
B`
f dRi
, L
scalar= 1
2 Tr h
D
BWµΦ
†D
BWµΦ i + µ
202 Tr h
Φ
†Φ i + λ
04
Tr h
Φ
†Φ i
2,
L
SS=
νQ
X
s=1
h Q ¯
sL6D
BW AGQ
sL+ ¯ Q
s uR6D
BAGQ
s uR+ ¯ Q
s dR6D
BAGQ
s dRi +
+
νL
X
t=1
h L ¯
tL6D
BW GL
tL+ ¯ L
t uR6D
BGL
t uR+ ¯ L
t dR6D
BGL
t dRi ,
R. Frezzotti M. Garofalo G.C. Rossi
Magnitude of the masses
SM particles have their phenomenological masses Superstrong interacting particles Q and L
m SS ∼ Λ T Λ QCD
The scalar mass m Φ ∼ Λ GU T → decoupled from the
dynamics
Hypercharge of Q and L
Non standard hypercharge assignment obtained requiring:
Left fermions SU(2)doublet Right fermions SU(2)singlet Q = τ
3+ Y
Anomalies are cancelled within quark and lepton sectors separately
ν Q and ν L generations of Q and L
[S. Weinberg, “ The Quantum Theory of Fields”, Vol. II]
q w ` w Q w L w
y u
L= 1 6 y ν
L= − 1 2 y U
L= 0 y N
L= 0 y u
R= 2 3 y ν
R= 0 y U
R= 1 2 y N
R= + 1 2 y d
L= 1 6 y el
L= − 1 2 y D
L= 0 y L
L= 0 y d
R= − 1 3 y el
R= −1 y D
R= − 1 2 y L
R= − 1 2 P y q 2 = 22 36 P
y 2 ` = 3 2 P
y Q 2 = 1 2 P y L 2 = 1 2
R. Frezzotti M. Garofalo G.C. Rossi
1-loop β-functions With the standard definitions
β x (g x ) = µ dg x
dµ , x = T, s, w, Y
and g T , g s , g w , g Y the coupling of SU(N T ), SU(N c ), SU(2 L ), U(1) respectively, we get
β T BSM M = − 11
3 N T − 4
3 (N c ν Q + ν L ) g T 3
(4π) 2 , ν Q = #Q generations β s BSM M = −
11
3 N c − 4
3 (N T ν Q + n g ) g 3 s
(4π) 2 , ν L = #L generations β w BSM M = −
2 11
3 − 1
3 n g (N c + 1) − 1
3 N T (N c ν Q + ν L ) g w 3
(4π) 2 , β Y BSM M =
2 3
22
36 N c + 3 2
n g + 1
2 N T (N c ν Q + ν L ) g Y 3
(4π) 2 ,
GUT normalization Tr
(g Y Y ) 2
= Tr
( 1 2 g w τ 3 ) 2
= Tr
( 1 2 g s λ 3 ) 2
= Tr
( 1 2 g T λ 3 T ) 2 setting N c = N T = n g = 3 and ν Q = ν L = 1 we get
g 1 2 := 4
3 g Y 2 , g 2 2 := g w 2 , g 3 2 := g 2 s , g 2 4 := 2 3 g T 2 PDG input m Z ∼ 91GeV α −1 1 (m Z ) = 4π/g 1 2 = 73.76 ± 0.02 While in the SM
g 1 2 := 5
3 g Y 2 , g 2 2 := g w 2 , g 2 3 := g s 2 .
PDG input m Z ∼ 91GeV α −1 1 (m Z ) = 4π/g 1 2 = 59.01 ± 0.02
R. Frezzotti M. Garofalo G.C. Rossi
GUT normalization Tr
(g Y Y ) 2
= Tr
( 1 2 g w τ 3 ) 2
= Tr
( 1 2 g s λ 3 ) 2
= Tr
( 1 2 g T λ 3 T ) 2 setting N c = N T = n g = 3 and ν Q = ν L = 1 we get
g 1 2 := 4
3 g Y 2 , g 2 2 := g w 2 , g 3 2 := g 2 s , g 2 4 := 2 3 g T 2 PDG input m Z ∼ 91GeV α −1 1 (m Z ) = 4π/g 1 2 = 73.76 ± 0.02 While in the SM
g 1 2 := 5
3 g Y 2 , g 2 2 := g w 2 , g 2 3 := g s 2 .
PDG input m Z ∼ 91GeV α −1 1 (m Z ) = 4π/g 1 2 = 59.01 ± 0.02
• m Z < µ < Λ T SM
β g
1= 41 10
g 1 3 (4π) 2 β g
2= − 19
6 g 2 3 (4π) 2 β g
3= −7 g 3 3
(4π) 2 BSSM
β g
1= 5 g 3 1 (4π) 2 β g
2= −3 g 2 3
(4π) 2 β g
3= −7 g 3 3
(4π) 2
• µ > Λ T SM
β g
1= 41 10
g 1 3 (4π) 2 β g
2= − 19
6 g 2 3 (4π) 2 β g
3= −7 g 3 3
(4π) 2 BSSM
β g
1= 8 g 3 1 (4π) 2 β g
2= 4
6 g 2 3 (4π) 2 β g
3= −3 g 3 3 (4π) 2
R. Frezzotti M. Garofalo G.C. Rossi
• m Z < µ < Λ T SM
β g
1= 41 10
g 1 3 (4π) 2 β g
2= − 19
6 g 2 3 (4π) 2 β g
3= −7 g 3 3
(4π) 2 BSSM
β g
1= 5 g 3 1 (4π) 2 β g
2= −3 g 2 3
(4π) 2 β g
3= −7 g 3 3
(4π) 2
• µ > Λ T SM
β g
1= 41 10
g 1 3 (4π) 2 β g
2= − 19
6 g 2 3 (4π) 2 β g
3= −7 g 3 3
(4π) 2 BSSM g 2 loses asymptotic freedom
β g
1= 8 g 3 1 (4π) 2 β g
2= 4
6
g 2 3
(4π) 2
β g
3= −3 g 3 3
(4π) 2
0 10 20 30 40 50 60 70 80
1e+02 1e+04 1e+06 1e+08 1e+10 1e+12 1e+14 1e+16 1e+18 1e+20
α-1
µ(GeV)
Figure: 1-loop running of α
i= g
i2/4π in the SM and in the BSSM.
The superstrong threshold is set to Λ
T= 1TeV
R. Frezzotti M. Garofalo G.C. Rossi
If we compare it with the MSSM
0 10 20 30 40 50 60 70 80
1e+02 1e+04 1e+06 1e+08 1e+10 1e+12 1e+14 1e+16 1e+18 1e+20
α-1
µ(GeV)
Figure: The 1-loop running of α
i= g
i2/4π in the BSMM and in the
MSSM. The superstrong and supersymmetry thresholds have been set
at Λ
T= Λ
M SSM= 1 TeV.
input Λ T Λ T 2-loop GUT Total value value threshold effect threshold
error ∆ A ∆ B ∆ C ∆ D ∆ E ∆ tot
α −1 1 0.02 0.15 0.02 0.6 0.42 0.75 α −2 2 0.02 0.2 0.03 0.8 0.42 0.93 α −3 3 0.05 0.25 0.06 0.75 0.42 0.90
α −4 4 1 0.5 3 3.2
∆ A : Phenomenological error at m z ∼ 91GeV
∆ B : Value of Λ T = 1 ÷ 2TeV
∆ C : Spread of LO to NLO matching function; with M L = 1 TeV M Q = 1.5 TeV and µ T = 1.25 TeV
∆ D : α −1 2loop (Λ GU T ) − α −1 1loop (Λ GU T )
∆ E : Taken from a supersymmetric SU(5) grand unified model (PDG), as a GUT candidate for our BSSM not yet identified
∆ tot = q
∆ 2 A + ∆ 2 B + ∆ 2 C + ∆ 2 D + ∆ 2 E
R. Frezzotti M. Garofalo G.C. Rossi
Figure: running of α
i= g
2i/4π in the SM and in the BSSM.
Unification of the SU(N T ) coupling requires adding N S purely superstrong interacting particles
N
SX
f =1
ψ ¯ f 6D G ψ f + m h ψ ¯ f ψ f m f ∼ Λ GU T
β g
4= − 17 3
12 8 + N S
g 4 3 (4π) 2 reasonable values of N S = 4, 6, 8
010 20 30 40 50 60 70 80
1e+02 1e+04 1e+06 1e+08 1e+10 1e+12 1e+14 1e+16 1e+18 1e+20
α-1
µ(GeV)
R. Frezzotti M. Garofalo G.C. Rossi
Summary of BSMM
Inspired from NP mechanism of elementary particle mass generation (R. Frezzotti talk)
SU(N T ) interaction with Q and L
Non standard hypercharge assignment of Q and L, necessary for the unification (not for the NP mechanism) Scalar mass m Φ ∼ Λ GU T ,
natural choice in the framework of the NP mechanism
however not crucial for gauge coupling unification
Including Ψ to unify the SU(N T ) coupling
Conclusions
Unification at the same accuracy as in MSSM Alternative hypercharge assignment
crucial for the unification
superstrongly confined “hadrons” with charge quantized in units of e/2
Superstrongly bound glueball state lighter than mesons (may be compatible with possible LHC resonance at ∼ 750 GeV)
R. Frezzotti M. Garofalo G.C. Rossi
m Φ = m higgs or m Φ ∼ Λ GU T
20 22 24 26 28 30 32 34
1e+16 1e+17 1e+18 1e+19 1e+20
α-1
µ(GeV)
without scalar with scalar
R. Frezzotti M. Garofalo G.C. Rossi
Standard hypercharge assignment Q and L g 1 2 := 5 3 g Y 2 like SM vs Non standard g 2 1 := 4 3 g Y 2
0 10 20 30 40 50 60 70 80
1e+02 1e+04 1e+06 1e+08 1e+10 1e+12 1e+14 1e+16 1e+18 1e+20
α-1
µ(GeV)