In this paper, we present a formalism for computing the non-vanishing Higgs μterms in a heterotic standard model. This is accomplished by calculating the cubic product of the cohomology groups associated with the vector bundle moduli (φ), Higgs (H) and Higgs conjugate (H̄) superfields. This leads to terms proportional to φHH̄ in the low energy superpotential which, for non-zero moduli expectation...

Global geometry of K3-fibration Calabi-Yau threefolds, with Hodge number h 2,1 = r+1, is used to define N = 4 softly broken SU(r+1) gauge theories, with the bare coupling constant given by the dual heterotic dilaton, and the mass of the adjoint hypermultiplet given by the heterotic string tension. The U(r +1) Donagi-Witten integrable model is also derived from the K3-fibration structure, with t...

Heterosis refers to a quantitative phenomenon in which F1 hybrid trait values exceed the mean of the parental values in a positive direction. Generally, it is dependent on a high degree of heterozygosity, which is maintained in hybrid breeding by developing parental lines in separate, genetically distinct heterotic groups. The mobility of small RNAs (sRNAs) that mediate epigenetic regulation of...

Advances in genotyping technologies have transformed the way breeding programs manage their genetic resources. The identification of single nucleotide polymorphisms (SNPs) can improve understanding diversity maize (Zea mays) inbred lines and classification into heterotic groups, which is useful determining certain crosses to obtain hybrids with higher yield performance. 293 was investigated 525...

The fields of the conjectured " heterotic " super–fivebrane sigma–model in ten dimensions are made out of a well known gravitational sector, the X and the ϑ, and of a still unknown heterotic sector which should be coupled to the Yang– Mills fields. We compute the one–loop d = 6 worldvolume and D = 10 target space Lorentz–anomalies which arise from the gravitational sector of the heterotic super...

Type I – heterotic duality in D=10 predicts various relations and constraints on higher order F couplings at different string loop levels on both sides. We prove the vanishing of two-loop corrections to the heterotic F 4 terms, which is one of the basic prediction from this duality. Furthermore, we show that the heterotic F 5 and (CP even) F 6 couplings are not renormalized at one loop. These r...

A study is made of the implications of heterotic string T -duality and extended gauge symmetry for the conjectured equivalence of heterotic and Type I superstrings. While at first sight heterotic string world-sheet dynamics appears to conflict with Type I perturbation theory, a closer look shows that Type I perturbation theory “miraculously” breaks down, in some cases via novel mechanisms, when...

Identification of quantitative trait loci (QTL) involved in the variation of hybrid value is of key importance for cross-pollinated species such as maize (Zea mays L.). In a companion paper, we illustrated a new QTL mapping population design involving a factorial mating between two multiparental segregating populations. Six biparental line populations were developed from four founder lines in t...

Abstract We discuss solutions of the heterotic string theory which are analogous to bosonic and superstring backgrounds related to coset conformal field theories. A class of exact ‘left-right symmetric’ solutions is obtained by supplementing the metric, antisymmetric tensor and dilaton of the superstring solutions by the gauge field background equal to the generalised Lorentz connection with to...

In this article we review four-dimensional string vacua with N = 2 space-time supersymmetry. In particular, we will discuss several aspects of the string-string duality between the heterotic string, compactified on K3 × T 2 , and the type II superstring compactified on a Calabi-Yau threefold. We investigate the massless supersymmetric spectra, showing agreement for a large class of dual heterot...