Grand unified string theories with non-Abelian gauge family symmetry in the free fermion formulaton

Journal Article · Thu Dec 15 00:00:00 EST 1994 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.50.7440· OSTI ID:6818586

Maslikov, A A ^[1]; Sergeev, S M ^[2]; Volkov, G G ^[3]

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1. Institute for High Energy Physics, Protvino, Moscow Region, 142284 (Russian Federation)
2. Branch of Institute of Nuclear Physics, Protvino, Moscow Region, 142284 (Russian Federation)
3. Institute for High Energy Physics, Protvino, Moscow Region, 142284 (Russian Federation) INFN Sezione de Padova and Dipartimento di Fisica Universita de Padova, Institute for High Energy Physics, Via Marzolo 8, 35100 Padua (Italy)

In the framework of four-dimensional heterotic superstring theory with free fermions we investigate the rank eight grand unified string theories (GUST's) which contain the SU(3)[sub [ital H]]-gauge family symmetry. GUST's of this type accommodate naturally three fermion families presently observed and, moreover, can describe a fermion mass spectrum without high-dimensional representations of conventional unification groups. We explicitly construct GUST's with the gauge symmetry [ital G]=SU(5)[times]U(1)[times][SU(3)[times]U(1)][sub [ital H]][contained in]SO(16) in the free complex fermion formulation. As the GUST's originating from Kac-Moody algebras (KMA's) contain only low-dimensional representations it is usually difficult to break the gauge symmetry. We solve this problem by taking for the observable gauge symmetry the diagonal subgroup [ital G][sup sym] of the rank 16 group [ital G][times][ital G][contained in]SO(16)[times]SO(16)[contained in]E[sub 8][times]E[sub 8]. Such a construction effectively corresponds to a level-two KMA, and therefore some higher-dimensional representations of the diagonal subgroup appear. This (because of [ital G][times][ital G]-tensor Higgs fields) allows one to break GUST symmetry down to SU(3[sup [ital c])][times]U(1)[sub em]. In this approach the observed electromagnetic charge [ital Q][sup em] can be viewed as a sum of two [ital Q][sup I] and [ital Q][sup II] charges of each [ital G] group. In this case below the scale where [ital G][times][ital G] breaks down to [ital G][sup sym] the spectrum does not contain particles with exotic fractional charges. In these GUST's there has to exist superweak'' light chiral matter.

• OSTI ID: 6818586
• Journal Information: Physical Review, D (Particles Fields); (United States), Vol. 50:12; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
GRAND UNIFIED THEORY
STRING MODELS
FERMIONS
FOUR-DIMENSIONAL CALCULATIONS
GAUGE INVARIANCE
HIGGS BOSONS
SO GROUPS
SPECTRA
SU-3 GROUPS
SU-5 GROUPS
U-1 GROUPS
COMPOSITE MODELS
ELEMENTARY PARTICLES
EXTENDED PARTICLE MODEL
FIELD THEORIES
INVARIANCE PRINCIPLES
LIE GROUPS
MATHEMATICAL MODELS
PARTICLE MODELS
POSTULATED PARTICLES
QUARK MODEL
SU GROUPS
SYMMETRY GROUPS
U GROUPS
UNIFIED GAUGE MODELS
UNIFIED-FIELD THEORIES
662110* - General Theory of Particles & Fields- Theory of Fields & Strings- (1992-)
662120 - General Theory of Particles & Fields- Symmetry
Conservation Laws
Currents & Their Properties- (1992-)