A way to reopen the window for electroweak baryogenesis
A way to reopen the window for electroweak baryogenesis
复制标题
重新打开电弱重子生成之窗的方法
DOI：
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发表时间：
2001
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影响因子：
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通讯作者：
Géraldine Servant
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文献类型：
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作者：
Géraldine Servant;Géraldine Servant
当允许弗里德曼方程出现偏差时，我们重新分析了电弱重子生成的球面子界。这些修改在膜宇宙学的背景下得到了充分的激发，它们的出现并不与四维引力的主要实验限制相冲突。虽然在核合成时受到抑制，但这些校正可以在电弱相变时占主导地位，并且在某些情况下提供冻结重子不对称性所需的膨胀量，而不需要强烈的一阶相变。鳞片束缚大大减弱，甚至可以消失，因此对希格斯粒子和停止质量的约束不再适用。因此，早期对宇宙学的这种修改重新打开了允许电弱重子生成的参数空间，考虑到 LEP 对希格斯质量施加的新限制，该参数空间已大大减少。与之前使用替代宇宙学扭转角球束缚的尝试相反，我们仍然认为电弱相变发生在辐射主导的宇宙中。宇宙正在快速膨胀，因为弗里德曼方程本身的修改不需要标量场，因此避免了相变完成后这个标量场衰变的问题以及它释放的熵稀释了相变时产生的重子不对称性的风险。 « less
We reanalyse the sphaleron bound of electroweak baryogenesis when allowing deviations to the Friedmann equation. These modifications are well motivated in the context of brane cosmology where they appear without being in conflict with major experimental constraints on four-dimensional gravity. While suppressed at the time of nucleosynthesis, these corrections can dominate at the time of the electroweak phase transition and in certain cases provide the amount of expansion needed to freeze out the baryon asymmetry without requiring a strongly first order phase transition. The sphaleron bound is substantially weakened and can even disappear so that the constraints on the higgs and stop masses do not apply anymore. Such modification of cosmology at early times therefore reopens the parameter space allowing electroweak baryogenesis which had been reduced substantially given the new bound on the higgs mass imposed by LEP. In contrast with previous attempts to turn around the sphaleron bound using alternative cosmologies, we are still considering that the electroweak phase transition takes place in a radiation dominated universe. The universe is expanding fast because of the modification of the Friedmann equation itself without the need for a scalar field and therefore evading the problem of the decay of this scalarmore » field after the completion of the phase transition and the risk that its release of entropy dilutes the baryon asymmetry produced at the transition.« less