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arXiv · hep-th/9401064

Minimal String Model in $Z_4$, $Z_6$ and $Z_8$ Orbifold Constructions

H. Kawabe·T. Kobayashi·N. Ohtsubo
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Abstract

We examine whether a minimal string model possessing the same massless spectra as the MSSM can be obtained from $Z_4$, $Z_6$ and $Z_8$ orbifold constructions. Using an anomaly cancellation condition of the target space duality symmetry, we derive allowable values of a level $k_1$ of U(1)$_Y$ for the minimal string model on the orbifolds through computer analyses. We investigate threshold corrections of the gauge coupling constants of SU(3), SU(2) and U(1)$_Y$ and examine consistencies of the model with the LEP experiments. It is found that $Z_4$ and $Z_8$-II can not derive the minimal string model but $Z_6$-I, $Z_6$-II and $Z_8$-I are possible to derive it with $13/12 \leq k_1\leq 41/30$, $16/15\leq k_1\leq 17/12$ and $1\leq k_1\leq 41/21$ respectively. The minimum values of the moduli on unrotated planes are estimated within the ranges of the levels.

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H. Kawabe, T. Kobayashi, N. Ohtsubo. 1994-03-02. Minimal String Model in $Z_4$, $Z_6$ and $Z_8$ Orbifold Constructions. https://arxiv.org/abs/hep-th/9401064

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