The mixing of graviphotons and dark brane photons to the Standard Model hypercharge is analyzed in full generality, in weakly-coupled string theory. Both the direct mixing as well as effective terms that provide mixing after inclusion of SM corrections are estimated to lowest order. The results are compared with Effective Field Theory (EFT) couplings, originating in a hidden large-N theory coupled to the SM where the dark photons are composite. The string theory mixing terms are typically subleading compared with the generic EFT couplings. The case where the hidden theory is a holographic theory is also analyzed, providing also suppressed mixing terms to the SM hypercharge.

中文翻译：

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弦（重力）光子、“暗膜光子”、全息术和超充电门户

在弱耦合弦理论中，对重力光子和暗膜光子与标准模型超电荷的混合进行了全面分析。直接混合以及在包含 SM 校正后提供混合的有效项都被估计为最低阶。结果与有效场理论 (EFT) 耦合进行了比较，该耦合源自隐藏的大 N 理论，该理论与暗光子合成的 SM 耦合。与通用 EFT 耦合相比，弦理论混合项通常是次要的。还分析了隐藏理论是全息理论的情况，还为 SM 超电荷提供了抑制混合项。