# Constraints on left-right symmetric and O(18) unified theories

## Abstract

Part I of this thesis contains a discussion on left-right symmetric models. The left-right symmetric gauge group makes parity violation a consequence of spontaneous symmetry breaking. These models have physical neutral Higgs bosons with flavor-violating couplings that follow from the enlarged Higgs sector required to break left-right symmetry. We show that the mass of such bosons must be in the multi-TeV region to avoid unacceptably large neutral kaon and B-meson transition amplitudes. The low energy theory based on the O(18) family unified theory is the subject of Part II. All fermions belong to a single complex irreducible representation of O(18). Perturbative unification and the desert hypothesis are assumed. Cosmology and low energy phenomenology are used to constrain the effective SU(3) x SU(2) x U(1) x Z/sub N/ theory at the weak scale. Two Higgs doublets are required in order to satisfy the combined constraints of the absence of heavy stable quarks, at most four ultralight neutrinos and sufficient charged current mixing among the three known quark generations. Four left- and four right-handed families of quarks and leptons are predicted.

- Authors:

- Publication Date:

- Research Org.:
- Stanford Univ., CA (USA)

- OSTI Identifier:
- 5794216

- Resource Type:
- Thesis/Dissertation

- Resource Relation:
- Other Information: Thesis (Ph. D.)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; UNIFIED GAUGE MODELS; FERMIONS; HIGGS BOSONS; IRREDUCIBLE REPRESENTATIONS; LEPTONS; O GROUPS; PARTICLE DECAY; PERTURBATION THEORY; QUARKS; REST MASS; SYMMETRY BREAKING; DECAY; DYNAMICAL GROUPS; ELEMENTARY PARTICLES; LIE GROUPS; MASS; MATHEMATICAL MODELS; PARTICLE MODELS; POSTULATED PARTICLES; SYMMETRY GROUPS; 645400* - High Energy Physics- Field Theory

### Citation Formats

```
Reno, M H.
```*Constraints on left-right symmetric and O(18) unified theories*. United States: N. p., 1985.
Web.

```
Reno, M H.
```*Constraints on left-right symmetric and O(18) unified theories*. United States.

```
Reno, M H. Tue .
"Constraints on left-right symmetric and O(18) unified theories". United States.
```

```
@article{osti_5794216,
```

title = {Constraints on left-right symmetric and O(18) unified theories},

author = {Reno, M H},

abstractNote = {Part I of this thesis contains a discussion on left-right symmetric models. The left-right symmetric gauge group makes parity violation a consequence of spontaneous symmetry breaking. These models have physical neutral Higgs bosons with flavor-violating couplings that follow from the enlarged Higgs sector required to break left-right symmetry. We show that the mass of such bosons must be in the multi-TeV region to avoid unacceptably large neutral kaon and B-meson transition amplitudes. The low energy theory based on the O(18) family unified theory is the subject of Part II. All fermions belong to a single complex irreducible representation of O(18). Perturbative unification and the desert hypothesis are assumed. Cosmology and low energy phenomenology are used to constrain the effective SU(3) x SU(2) x U(1) x Z/sub N/ theory at the weak scale. Two Higgs doublets are required in order to satisfy the combined constraints of the absence of heavy stable quarks, at most four ultralight neutrinos and sufficient charged current mixing among the three known quark generations. Four left- and four right-handed families of quarks and leptons are predicted.},

doi = {},

journal = {},

number = ,

volume = ,

place = {United States},

year = {1985},

month = {1}

}