We begin with an $E_{8}\times E_{8}$ Heterotic model broken to an $SU(5)_{gauge}$ and a mirror $SU(5)_{gauge}$, where one $SU(5)$ and its spectrum is identified as the visible sector while the other can be identified as a hidden mirror world. In both cases we obtain the minimal supersymmetric standard model spectrum after Wilson-line symmetry-breaking enhanced by a low energy R-parity enforced by a local (or global) $U(1)_{X}$-symmetry. Using Heterotic/$F$-theory duality, we show how to eliminate the vector-like exotics which were obtained in previous constructions. In these constructions, the Calabi-Yau {[}CY{]} four-fold was defined by an elliptic fibration with section over a base $B_{3}$ and a GUT surface given by $K3/\mathbb{Z}_{2}=$ Enriques surface. In the present paper we construct a quotient CY four-fold fibered by tori with two elliptic structures given by a a pair of sections fibered over the Enriques surface. Using Heterotic/$F$-theory duality we are able to define the cohomologies used to derive the massless spectrum.
Our model for the 'correct' $F$-theory dual of a Heterotic model with Wilson-line symmetry-breaking builds on prior literature but employs the stack-theoretic version of the dictionary between the Heterotic semi-stable $E_{8}$-bundles with Yang-Mills connection and the $dP_{9}$-fibrations used to construct the $F$-theory dual.
The single-valued projection (sv) is a relation between scattering amplitudes of gauge bosons in heterotic and open superstring theories. Recently we have studied sv from the aspect of nonlinear sigma models [1], where the gauge physics of open string sigma model is under the Wilson loop representation but the gauge physics of heterotic string sigma model is under the fermionic representation since the Wilson loop representation is absent in the heterotic case. There we showed that the sv comes from a sum of six radial orderings of heterotic vertices on the complex plane. In this paper, we pro…
We present how to construct elliptically fibered K3 surfaces via Weierstrass models which can be parametrized in terms of Wilson lines in the dual heterotic string theory. We work with a subset of reflexive polyhedras that admit two fibers whose moduli spaces contain the ones of the $E_{8}\times E_{8}$ or $\frac{Spin(32)}{\mathbb{Z}_{2}}$ heterotic theory compactified on a two torus without Wilson lines. One can then interpret the additional moduli as a particular Wilson line content in the heterotic strings. A convenient way to find such polytopes is to use graphs of polytopes where links are…
We study to what extent Wilson lines in heterotic Calabi-Yau compactifications lead to non-trivial H-flux via Chern-Simons terms. Wilson lines are basic ingredients for Standard Model constructions but their induced H-flux may affect the consistency of the leading order background geometry and of the two-dimensional worldsheet theory. Moreover H-flux in heterotic compactifications would play an important role for moduli stabilization and could strongly constrain the supersymmetry breaking scale. We show how to compute H-flux and the corresponding superpotential, given an explicit complete inte…
Z_3 orbifolds of the SO(32) heterotic string: 1 Wilson line embeddings
本文研究了具有一条离散Wilson线的6维Z_3轨道上SO（32）杂化弦的紧化。给出了所有可能的嵌入的完整集合，总共159个。SO（32）的不破断子群列表。最近由J. E. Kim [hep-th/0301177]对于半现实的E_8 x E_8杂种弦模型，发生在几个嵌入中，以及在统一弦模型中可能感兴趣的其他组。讨论了额外规范群因子的隐藏程度，并与E_8 × E_8的情况进行了比较。沿着存在有效隐藏扇区的平坦方向，这里描述的嵌入提供了在E_8 x E_8杂种弦中不可能的隐藏规范群。
We construct non-geometric string compactifications by using the F-theory dual of the heterotic string compactified on a two-torus with two Wilson line parameters, together with a close connection between modular forms and the equations for certain K3 surfaces of Picard rank $16$. We construct explicit Weierstrass models for all inequivalent Jacobian elliptic fibrations supported on this family of K3 surfaces and express their parameters in terms of modular forms generalizing Siegel modular forms. In this way, we find a complete list of all dual non-geometric compactifications obtained by the …
In this paper we compute the gravitational couplings of the heterotic string compactified on $(K3\times T^2)/\mathbb{Z}_N$ and $E_8\times E_8$ and predict the Gopakumar Vafa invariants of the dual Calabi Yau manifold in presence of Wilson lines. Here $\mathbb{Z}_N$ acts as an automorphism on $K3$ associated with the conjugacy classes of $M_{23}$ and a shift of $1/N$ on one of the $S^1$ of $T^2$. We study in detail the cases $N=2,3$ for standard and several non-standard embeddings where $K3$ is realized as toroidal orbifolds $T^4/\mathbb{Z}_4$ and $T^4/\mathbb{Z}_3$. From these computations we …
Finding the $F$-theory dual of a Heterotic model with Wilson-line symmetry breaking presents the challenge of achieving the dual $\mathbb{Z}_{2}$-action on the $F$-theory model in such a way that the $\mathbb{Z}_{2}$-quotient is Calabi-Yau with an Enriques $\mathrm{GUT}$ surface over which $SU\left(5\right)_{gauge}$ symmetry is maintained. We propose a new way to approach this problem by taking advantage of a little-noticed choice in the application of Narasimhan-Seshadri equivalence between real $E_{8}$-bundles with Yang-Mills connection and their associated complex holomorphic $E_{8}^{\mathb…
The $Z_2\times Z_2$ heterotic string orbifold gives rise to a large space of phenomenological three generation models that serves as a testing ground to explore how the Standard Model of particle physics may be incorporated in a theory of quantum gravity. Recently, we demonstrated the existence of type 0 $Z_2\times Z_2$ heterotic string orbifolds in which there are no massless fermionic states. In this paper we demonstrate the existence of non--supersymmetric tachyon--free $Z_2\times Z_2$ heterotic string orbifolds that do not contain any massless bosonic states from the twisted sectors. We du…
We study a class of 6d $\mathcal{N}=(1,0)$ non-geometric vacua of the $\text{Spin}(32)/\mathbb Z_2$ heterotic string which can be understood as fibrations of genus-two curves over a complex one-dimensional base. The 6d $\mathcal{N}=(1,0)$ theories living on the defects that arise when the genus-two fiber degenerates at a point of the base are analyzed by dualizing to F-theory on elliptic K3-fibered non-compact Calabi-Yau threefolds. We consider all possible degenerations of genus-two curves and systematically attempt to resolve the singularities of the dual threefolds. As in the analogous non-…
Institute of Physics of the Czech Academy of Sciences（捷克科学院物理研究所）；Scuola Normale Superiore（比萨高等师范学院）；INFN, Sezione di Pisa（意大利国家核物理研究所比萨分部）；Deutsches Elektronen-Synchrotron DESY（德国电子同步加速器中心）
A few nine-dimensional interpolating models with two parameters are constructed and the massless spectra are studied by considering compactification of heterotic strings on a twisted circle with Wilson line. It is found that there are some conditions between radius R and Wilson line A under which the gauge symmetry is enhanced. In particular, when the gauge symmetry is enhanced to SO(18) \times SO(14), the cosmological constant is exponentially suppressed. We also construct a non-supersymmetric string model which is tachyon-free in all regions of moduli space and whose gauge symmetry involves …
We point out a simple realization of gauge symmetry enhancement by Wilson lines in QFT with twisted compactification in extra dimensions. We illustrate this in the field contents taken from heterotic supergravity in arbitrary dimensions toroidally compactified.
We construct non-geometric compactifications by using the F-theory dual of the heterotic string compactified on a two-torus, together with a close connection between Siegel modular forms of genus two and the equations of certain K3 surfaces. The modular group mixes together the Kähler, complex structure, and Wilson line moduli of the torus yielding weakly coupled heterotic string compactifications which have no large radius interpretation.
We revisit the calculation of one-loop corrections to the partition functions of a string ending on a circular or straight line in type IIB string theory on $AdS_3\times S^3 \times T^4$ supported by a mixture of 3-form fluxes depending on a parameter $q$ (with $q=0$ being R-R and $q=1$ pure NS-NS cases). Correcting earlier results in the literature, we find that the partition function depends on $q$ only through rescaled tension $T= T_0/(1-q^2)$.
We analyze Yukawa unification in the the context of $E_8\times E_8$ heterotic Calabi-Yau models which rely on breaking to a GUT theory via a non-flat gauge bundle and subsequent Wilson line breaking to the standard model. Our focus is on underlying GUT theories with gauge group $SU(5)$ or $SO(10)$. We provide a detailed analysis of the fact that, in contrast to traditional field theory GUTs, the underlying GUT symmetry of these models does not enforce Yukawa unification. Using this formalism, we present various scenarios where Yukawa unification can occur as a consequence of additional symmetr…
We investigate the structure of the moduli space of 9D heterotic interpolating models with a complete set of Wilson line backgrounds and a radius parameter by computing the one-loop partition functions and the cosmological constants and by deriving the massless spectra, paying attention to the region $a \approx 0$ where supersymmetry is asymptotically restoring. We find some special planes and points in the moduli space where the gauge symmetry is enhanced and/or massless fermions appear. The gauge symmetry is maximally enhanced at the minima of the one-loop effective potential where the cosmo…
Higgs Doublets, Split Multiplets and Heterotic SU(3)_C x SU(2)_L x U(1)_Y Spectra
本文提出了一种利用Wilson谱线计算杂种优势真空无质量谱的方法。这一结果被应用于一类特殊的真空，它具有环面纤维Calabi-Yau三重环上的全纯SU（5）-丛，其基本群为Z_2。这些真空导致了具有标准模型规范群SU（3）_C x SU（2）_L x U（1）_Y和三个夸克/轻子族的低能理论。计算了无质量谱，包括希格斯双重态的多重性。
The superpotential in four-dimensional heterotic effective theories contains terms arising from holomorphic Chern-Simons invariants associated to the gauge and tangent bundles of the compactification geometry. These effects are crucial for a number of key features of the theory, including vacuum stability and moduli stabilization. Despite their importance, few tools exist in the literature to compute such effects in a given heterotic vacuum. In this work we present new techniques to explicitly determine holomorphic Chern-Simons invariants in heterotic string compactifications. The key technica…
给出了确定一类实际杂化弦真空的无质量谱的一种形式。这些真空由三重环面纤维Calabi-Yau上的SU（5）全纯丛组成，基本群为Z_2，导致了具有标准模型规范群（SU（3）_C x SU（2）_L x U（1）_Y）/Z_6和三族夸克和轻子的低能理论。给出了确定这些丛的层上同调和Z_2在每个上同调群上的表示的方法。结合Z_2 Wilson线的作用，计算了无质量谱，并作了列表和讨论。
We search for the three-generation standard-like and/or Pati-Salam models from the $SO(32)$ heterotic string theory on smooth, quotient complete intersection Calabi-Yau threefolds with multiple line bundles, each with structure group $U(1)$. These models are S- and T-dual to intersecting D-brane models in type IIA string theory. We find that the stable line bundles and Wilson lines lead to the standard model gauge group with an extra $U(1)_{B-L}$ via a Pati-Salam-like symmetry and the obtained spectrum consists of three chiral generations of quarks and leptons, and vector-like particles. Green…
We study heterotic Calabi-Yau models with hypercharge flux breaking, where the visible E8 gauge group is directly broken to the standard model group by a non-flat gauge bundle, rather than by a two-step process involving an intermediate grand unified theory and a Wilson line. It is shown that the required alternative E8 embeddings of hypercharge, normalized as required for gauge unification, can be found and we classify these possibilities. However, for all but one of these embeddings we prove a general no-go theorem which asserts that no suitable geometry and vector bundle leading to a standa…
