Number of generations in free fermionic string models

Journal Article · Sat Jul 15 04:00:00 EDT 1995 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.52.1026· OSTI ID:82211

Giannakis, I ^[1]; Nanopoulos, D V ^[1]; Yuan, K ^[1]

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1. Center for Theoretical Physics, Department of Physics, Texas A&M University, College Station, Texas 77843-4242 (United States)

In string theory there seems to be an intimate connection between spacetime and world-sheet physics. Following this line of thought we investigate the family problem in a particular class of string solutions, namely, the free fermionic string models. We find that the number of generations {ital N}{sub {ital g}} is related to the index of the supersymmetry generator of the underlying {ital N}=2 internal superconformal field theory which is always present in any {ital N}=1 spacetime supersymmetric string vacuum. We also derive a formula for the index and thus for the number of generations which is sensitive to the boundary condition assignments of the internal fermions and to certain coefficients which determine the weight with which each spin structure of the model contributes to the one-loop partition function. Finally we apply our formula to several realistic string models in order to derive {ital N}{sub {ital g}} and we verify our results by constructing explicitly the massless spectrum of these string models.

• Research Organization: Texas A&M Research Foundation
• DOE Contract Number: FG05-91ER40633
• OSTI ID: 82211
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 2 Vol. 52; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BOUNDARY CONDITIONS
CONFORMAL GROUPS
FERMIONS
QUANTUM FIELD THEORY
SPACE-TIME
SPIN
STRING MODELS
SUPERSYMMETRY