The Importance of Being Rigid: D6-Brane Model Building on $T^6/Z_2 x Z_6'$ with Discrete Torsion
The Importance of Being Rigid: D6-Brane Model Building on $T^6/Z_2 x Z_6'$ with Discrete Torsion
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DOI：
10.1016/j.nuclphysb.2012.11.011
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发表时间：
2012-09
期刊：
影响因子：
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通讯作者：
G. Honecker;M. Ripka;W. Staessens
中科院分区：
文献类型：
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作者：
G. Honecker;M. Ripka;W. Staessens
考虑了离散扭转下T6/Z2×Z6‘上IIA型定向折叠上刚性D6膜的建模问题。通过证明不同晶格取向之间的新对称性，系统地搜索粒子物理模型大大减少了。对无物质的刚性D6膜进行了分类，并根据离散的威尔逊线和位移参数区分了定向不变D6膜上的SO(2N)和USP(2N)规范因子。对奇异物质不存在的约束禁止了局部MSSM和左右对称模型的整体完成，而找到了全局定义的超对称Pati-Salam模型。对于后者，只有一代粒子具有微扰汤川耦合。简要讨论了少量奇异物质的质量和阿贝尔对称性的作用。最后但并非最不重要的是，对于所有三个大约相同量级的两环体积，可以在一个回路实现规范耦合的统一，而对于高度各向同性的选择，在TeV范围内的低弦标度与规范和引力耦合的观测强度是相容的。
Model building with rigid D6-branes on the Type IIA orientifold on T6/Z2×Z6′with discrete torsion is considered. The systematic search for models of particle physics is significantly reduced by proving new symmetries among different lattice orientations. Suitable rigid D6-branes without matter in adjoint and symmetric representations are classified, and SO(2N) and USp(2N) gauge factors on orientifold invariant D6-branes are distinguished in terms of their discrete Wilson line and displacement parameters. Constraints on the non-existence of exotic matter prohibit global completions of local MSSM and left–right symmetric models, while globally defined supersymmetric Pati–Salam models are found. For the latter, only one particle generation possesses perturbative Yukawa couplings. Masses for the mild amount of exotic matter and the role of Abelian symmetries are briefly discussed. Last but not least, it is shown that for all three two-torus volumes of about the same order of magnitude, gauge coupling unification at one loop can be achieved, while for highly unisotropic choices a low string scale in the TeV range is compatible with the observed strengths of gauge and gravitational couplings.