Large-scale magnetic fields can explain the baryon asymmetry of the Universe
Large-scale magnetic fields can explain the baryon asymmetry of the Universe
复制标题
大尺度磁场可以解释宇宙的重子不对称性
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
K. Kamada
中科院分区：
文献类型：
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作者：
Tomohiro Fujita;K. Kamada
原始宇宙中的螺旋超磁场可以通过手征异常产生观测到的重子不对称性，而没有任何超出粒子物理标准模型的成分。虽然它们没有产生$B-L$不对称性，但产生的重子不对称性在球化子冲刷效应中幸存下来，因为产生过程在电弱相变之前保持活跃。通过数值求解Boltzmann方程，找到了一个吸引子解，证明了如果耀变体观测所指示的大尺度磁场具有负螺旋度，并且存在于电弱相变之前的早期宇宙中，那么我们宇宙的重子不对称性是可以解释的。我们还导出了螺旋磁场强度的上界，它比宇宙微波背景约束更严格，以避免重子不对称性的过度产生。
Helical hypermagnetic fields in the primordial Universe can produce the observed amount of baryon asymmetry through the chiral anomaly without any ingredients beyond the standard model of particle physics. While they generate no $B-L$ asymmetry, the generated baryon asymmetry survives the spharelon washout effect, because the generating process remains active until the electroweak phase transition. Solving the Boltzmann equation numerically and finding an attractor solution, we show that the baryon asymmetry of our Universe can be explained, if the present large-scale magnetic fields indicated by the blazar observations have a negative helicity and existed in the early Universe before the electroweak phase transition. We also derive the upper bound on the strength of the helical magnetic field, which is tighter than the cosmic microwave background constraint, to avoid the overproduction of baryon asymmetry.