A mini-landscape of exact MSSM spectra in heterotic orbifolds

Abstract

We explore a "fertile patch" of the heterotic landscape based on a 6 -II orbifold with SO(10) and E 6 local GUT structures. We search for models allowing for the exact MSSM spectrum. Our result is that of order 100 out of a total 3 × 10 4 inequivalent models satisfy this requirement.

Rigid D6-branes on $ {{{{T^6}}} \left/ {{\left( {{Z_2} \times {Z_{2M}} \times \Omega \mathcal{R}} \right)}} \right.} $ with discrete torsion

“…The Z 3 (and Z 6 ) invariant lattice is the root lattice of A 2 = SU (3) or equivalently G 2 (observe that the lattices coincide even though the simple roots differ). It has fixed points under the Z 3 subsymmetry (1,2,3) and under the Z 2 subsymmetry (1,4,5,6), where 2 Z 6 ↔ 3 and 4 Z 6 → 5 Z 6 → 6. The A-type lattices have the coordinate orientation x 2i−1 along the 1-cycle π 2i−1 (depicted in green); for the B-type lattices x 2i−1 is along π 2i−1 + π 2i (depicted in yellow).…”

“…There are several approaches to identify promising string vacua each of which is well motivated, see e.g. [4][5][6][7] for heterotic orbifolds, [8,9] for heterotic Calabi-Yau compactifications with SU (N ) bundles and [10,11] with U (N ) bundles, [12][13][14][15] for local IIB models, [16][17][18] for Ftheory and [19,20] for Gepner models. While the techniques for identifying the gauge group and chiral matter spectrum are rather straightforward in all approaches, an investigation of the exact field theory is typically constrained to vacua, where e.g.…”

Three-generation asymmetric orbifold models from heterotic string theory

“…To specify the model, we take the (22,6)-dimensional Narain lattice A 11 2 × E 6 as a starting point, and also take a Z 3 shift vector as…”

“…Especially, in the framework of heterotic Z N or Z N × Z M orbifold compactifications [1,2], embedding a supersymmetric standard model or a higher dimensional grand unified theory into heterotic string theory is considered [3][4][5][6][7][8][9][10][11][12][13][14] (also see a review [15]). Since strings on an orbifold can be described by a solvable worldsheet conformal field theory [16,17], it is possible to calculate Yukawa couplings and selection rules [18][19][20][21][22].…”

750 GeV diphotons and supersymmetric grand unification

“…Simple bottom-up constructions of this type were presented in [3][4][5][6][7]. Vector-like 'exotics' are very common in string model constructions such as D-brane theories [8] or heterotic string compactifications [9]. The possibility that these exotics mediate the diphoton signal has been considered in [10][11][12][13][14][15][16][17].…”