Direct Compactification of Heterotic Strings, Modular Invariance and Three Families of Chiral Fermions

1987 ◽  
pp. 453-466
Author(s):  
Da-Xi Li
1990 ◽  
Vol 05 (08) ◽  
pp. 1529-1549 ◽  
Author(s):  
AKIRA FUJITSU ◽  
TETSURO KITAZOE ◽  
MASAYOSHI TABUSE ◽  
HARUHIKO NISHIMURA

Symmetry breaking patterns of E8×E′8 on Z3 orbifold are completely analyzed for physically acceptable models by using a kind of Weyl transformation and modular invariance. It is shown that SU(3)×SU(2)×U(1)n cannot be obtained by using any kind of a shift vector and Wilson lines and that the minimal group including SU(3)×SU(2)×U(1) is SU(3)2×U(1)n which is realized by a shift vector and Wilson lines. All models accessible to realistic low energy theories are listed out and an example is described to get SU(3)×SU(2)×UY(1) by using Higgs mechanism with anomalous U(1) channel. The example is able to give massless quark, lepton and Higgs to suppress proton decay by Planck mass scale and to make left-handed neutrino massless.


1990 ◽  
Vol 05 (15) ◽  
pp. 3053-3069
Author(s):  
ROBERT J. BUDZYŃSKI ◽  
MICHAL A. SPALIŃSKI

The free energy of the heterotic string is calculated in the covariant lattice formalism. It is shown that requiring modular invariance and correct statistics leads to a unique answer, which agrees with the known result obtained by path integral methods.


2017 ◽  
Vol 188 (01) ◽  
pp. 106-112 ◽  
Author(s):  
S.K. Nechaev ◽  
K. Polovnikov

1987 ◽  
Vol 195 (2) ◽  
pp. 202-208 ◽  
Author(s):  
Francesco Ravanini ◽  
Sung-Kil Yang

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Xiaokang Du ◽  
Fei Wang

Abstract Modular flavor symmetry can be used to explain the quark and lepton flavor structures. The SUSY partners of quarks and leptons, which share the same superpotential with the quarks and leptons, will also be constrained by the modular flavor structure and show a different flavor(mixing) pattern at the GUT scale. So, in realistic modular flavor models with SUSY completion, constraints from the collider and DM constraints can also be used to constrain the possible values of the modulus parameter. In the first part of this work, we discuss the possibility that the S3 modular symmetry can be preserved by the fixed points of T2/ZN orbifold, especially from T2/Z2. To illustrate the additional constraints from collider etc on modular flavor symmetry models, we take the simplest UV SUSY-completion S3 modular invariance SU(5) GUT model as an example with generalized gravity mediation SUSY breaking mechanism. We find that such constraints can indeed be useful to rule out a large portion of the modulus parameters. Our numerical results show that the UV-completed model can account for both the SM (plus neutrino) flavor structure and the collider, DM constraints. Such discussions can also be applied straightforwardly to other modular flavor symmetry models, such as A4 or S4 models.


2005 ◽  
Vol 20 (01) ◽  
pp. 99-128 ◽  
Author(s):  
B. B. DEO ◽  
L. MAHARANA

A string in four dimensions is constructed by supplementing it with 44 Majorana fermions. The later are represented by 11 vectors in the bosonic representation SO (D-1,1). The central charge is 26. The fermions are grouped in such a way that the resulting action is worldsheet supersymmetric. The energy–momentum and current generators satisfy the super-Virasoro algebra. GSO projections are necessary for proving modular invariance. Space–time supersymmetry algebra is deduced and is substantiated for specific modes of zero mass. The symmetry group of the model can descend to the low energy standard model group SU (3)× SU L(2)× U Y(1) through the Pati–Salam group.


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