References - Bogoliubov Laboratory of Theoretical Physics - JINR

In the studied models, we set a Z ′ with a mass of 1 TeV. The decay width for the flipped
and secluded model are respectively 17.89 and 19.54 GeV. We consider ideal situations,
that is, the values of polarization for electron and positron are respectively P e − = −1 and
Pe + = +1. As we can see from figures 2, these asymmetries show that the flipped and
secluded model can be distinguished successfully at ILC energies. With the choices of the
VEVs, u and v the VEVs of φ and H, respectively, and also g which implies the same
B−L
Z ′ mass in both models, the asymmetries are larger at the peak in the flipped model than
in the secluded model. This is because the Z ′ in the latter model has identical vectorial
couplings and the axial couplings vanish when zH =0.
couplings in
In fact, the secluded model considered as a B − L gauge model the gi V,A
Eq. (4) are exactly the same of the standard model, and f i A =0andthefV ’s are given
Cross Section [pb]
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8
7
6
5
4
3
2
1
0
e + e - --->mu + mu -
500 600 700 800 900 1000 1100 1200
s 1/2 (GeV)
B-L Flipped
B-L Secluded
Forward-backward Asymmetry
0,8
0,6
0,4
0,2
0,0
-0,2
-0,4
-0,6
e + e - --->mu + mu -
500 600 700 800 900 1000 1100 1200
s 1/2 (GeV)
(a) (b)
B-L Flipped
B-L Secluded
Figure 1: (a) Cross section for e + e − → μ + μ − in function of s. (b) Forward-backward asymmetry for
the same process.
Asymmetries
1,0
0,8
0,6
0,4
0,2
0,0
-0,2
-0,4
-0,6
-0,8
Flipped B-L Model
e + e - --> mu + mu -
M Z' =1000 GeV
-1,0
700 800 900 1000 1100
s 1/2 (GeV)
Polarization Asymmetry
Combined LR, FB Asymmetry
Left-Right Asymmetry
Asymmetries
0,020
0,015
0,010
0,005
0,000
-0,005
-0,010
-0,015
-0,020
Secluded B-L Model
e + e - --> mu + mu -
M Z' =1000 GeV
Polarization Asymmetry
Combined LR,FB Asymmetry
Left-Right Asymmetry
700 800 900
s
1000 1100
1/2 (GeV)
(a) (b)
Figure 2: (a) Polarization asymmetries in the flipped model. (b) The same as in (a) for the secluded
model.
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