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arXiv 1201.3485hep-phnucl-th
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重子物质局域宇称破缺的双轻子过剩

Dilepton excess from local parity breaking in baryon matter

A. A. Andrianov, V. A. Andrianov, D. Espriu, X. Planells

摘要:

我们认为,局部宇称破缺引起的拓扑电荷在大的温度和/或凝聚的赝标介子在等重态通道大重子密度可能是负责大量的双轻子过剩,发现低不变质量和中等值的$p_T$在中心重离子碰撞。这一至今无法解释的增强可以通过两种效应的结合来理解,这两种效应导致了相对于基于传统强子过程的理论预测而言的$e^+e^-$和$μ^+ μ^-$对的过量:(a)由于局域宇称破缺,在这样的核介质中传播的光子和矢量介子的色散关系的修改;(b)新衰变通道的出现,在通常的真空中,这是QCD的宇称守恒所禁止的。可能的签名,这种效果和其检测的前景进行了讨论。

英文摘要:

We propose that local parity breaking induced by a large-scale fluctuation of topological charge at large temperatures and/or condensation of pseudoscalar mesons in the isotriplet channel for large baryon densities may be responsible for the substantial dilepton excess that is found for low invariant masses and moderate values of $p_T$ in central heavy ions collisions. This insofar unexplained enhancement could be understood by a combination of two effects leading both to an excess of $e^+e^-$ and $μ^+ μ^-$ pairs with respect to theoretical predictions based on conventional hadronic processes: (a) a modification of the dispersion relation of photons and vector mesons propagating in such a nuclear medium due to local parity breaking; (b) the appearance of new decay channels, forbidden by parity conservation in QCD in the usual vacuum. Possible signatures of this effect and perspectives for its detection are discussed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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