Title: Effective field theory and keV lines from dark matter Show Chinese title

Title: 有效场论和暗物质的keV线

Abstract: We survey operators that can lead to a keV photon line from dark matter decay or annihilation. We are motivated in part by recent claims of an unexplained 3.5 keV line in galaxy clusters and in Andromeda, but our results could apply to any hypothetical line observed in this energy range. We find that given the amount of flux that is observable, explanations in terms of decay are more plausible than annihilation, at least if the annihilation is directly to Standard Model states rather than intermediate particles. The decay case can be explained by a scalar or pseudoscalar field coupling to photons suppressed by a scale not far below the reduced Planck mass, which can be taken as a tantalizing hint of high-scale physics. The scalar case is particularly interesting from the effective field theory viewpoint, and we discuss it at some length. Because of a quartically divergent mass correction, naturalness strongly suggests the theory should be cut off at or below the 1000 TeV scale. The most plausible such natural UV completion would involve supersymmetry. These bottom-up arguments reproduce expectations from top-down considerations of the physics of moduli. A keV line could also arise from the decay of a sterile neutrino, in which case a renormalizable UV completion exists and no direct inference about high-scale physics is possible. Show Chinese abstract

Abstract: 我们综述了可能导致暗物质衰变或湮灭产生keV光子线的算符。 我们部分受到最近关于星系团和仙女座中未解释的3.5 keV线的声明的启发，但我们的结果可能适用于该能量范围内观察到的任何假设线。 我们发现，考虑到可观测的通量，与湮灭相比，用衰变来解释更为合理，至少如果湮灭直接到标准模型状态而不是中间粒子的话。 衰变情况可以用一个标量或赝标量场来解释，该场与光子耦合，其尺度不远离约化普朗克质量，这可以看作是高能物理的一个诱人的暗示。 从有效场论的角度来看，标量情况特别有趣，我们对此进行了详细讨论。 由于四次发散的质量修正，自然性强烈表明该理论应在1000 TeV或更低的尺度上截断。 最可能的这种自然的紫外完成将涉及超对称。 这些自下而上的论点再现了从模场物理的自上而下考虑中得出的预期。 keV线也可能来自惰性中微子的衰变，在这种情况下存在一个可重整化的紫外完成，无法直接推断高能物理的情况。