Stable three generation standard-like model from a tachyonic ten dimensional heterotic-string vacuum

Abstract

Recently it was proposed that the ten dimensional tachyonic superstring vacua may serve as good starting points for the construction of viable phenomenological models. Such phenomenologically viable models enlarge the space of possible string solutions, and may offer novel insight into some of the outstanding problems in string phenomenology. In this paper we present a three generation standard-like model that may be regarded as a compactification of a ten dimensional tachyonic vacuum. We discuss the features of the model as compared to a similar model that may be regarded as compactification of the ten dimensional SO(16) × SO(16) heterotic-string. We further argue that in the four dimensional model all the geometrical moduli are fixed perturbatively, whereas the dilaton may be fixed by hidden sector non-perturbative effects. *

Supersymmetry Breaking and Stability in String Vacua: brane dynamics, bubbles and the swampland

“…This setting therefore offers the opportunity to compare probe computations with string amplitude computations. Specifically, we shall consider the uncharged 8-branes in the orientifold models, since their back-reacted geometry is described by the static Dudas-Mourad solution 76 [31] that we have described in Section 3. Furthermore, the other globally known back-reacted geometry in this setting pertains to extremal D1-branes, and 8-branes are the only probes (of different dimension) whose potential can be reliably computed in this case, since they can wrap the internal S 7 in the near-horizon AdS 3 × S 7 throat.…”

“…the DBI action evaluates to S p = − N p T p d p+1 x e (p+1)A(y)−Φ(y) ≡ − N p T p d p+1 xV p8 , (6.56) 76 The generalization to non-extremal p-branes of different dimensions would entail solving non-integrable systems, whose correct boundary conditions are not well-understood hitherto. Moreover, a reliable probe-brane regime would exclude the pinch-off asymptotic region, thereby requiring numerical computations.…”

“…In the same spirit, three-generation non-tachyonic heterotic models were constructed in[74]. Recently, lower-dimensional non-tachyonic models have been realized compactifying ten-dimensional tachyonic superstrings[75,76].…”

Towards the classification of tachyon-free models from tachyonic ten-dimensional heterotic string vacua

“…In addition to the supersymmetric, and non-supersymmetric SO(16) × SO (16), models, heterotic string theory gives rise to models that are tachyonic in ten dimensions [2,8,9]. Recently, it was argued that these ten dimensional tachyonic vacua can also serve as good starting points for constructing tachyon free phenomenologically viable models [10,11]. Whereas in the supersymmetric and non-supersymmetric SO(16) × SO (16) heterotic string the ten dimensional tachyons are projected out by the same projectors, they can be projected in the four dimensional models by using alternative projectors.…”

On Non-Supersymmetric String Model Building

“…However, until recently the relative investigation mainly restricted in supersymmetric models. The absence of experimental evidence in favour of SUSY motivates the extension of the quest for the SM in the domain of non-supersymmetric string vacua [1,2,3,4,5,6,7,8,9]. As a matter of fact, we can construct consistent string models without spacetime supersymmetry.…”