讲座主题：CDF W mass anomaly from a dark sector with a Stueckelberg-Higgs portal

专家姓名：刘佐伟

工作单位：南京大学

讲座时间：2022年5月20日 10:00-11:30

讲座地点：腾讯会议：461-137-584

主办单位：十大网投平台大全下载物理与电子信息学院

内容摘要：

We propose an explanation to the new W mass measurement recently reported by the CDF collaboration, which is larger than the standard model expectation by about 7 standard deviations. To alleviate the tensions that are imposed on the electroweak sector by the new W mass measurement, we carry out an analysis in the Stueckelberg extended standard model where a new neutral gauge boson appears which mixes with the two neutral gauge bosons in the electroweak sector both via the Stueckelberg mass terms and via the gauge invariant Stueckelberg-Higgs portal interaction and spoils the custodial symmetry at the tree level so that the simple relation between the W boson mass and the Z boson mass does not hold. We find that such an extension increases the W boson mass if the new gauge boson mass is larger than the Z boson mass. We further show that there exists a significant part of the parameter space in the extended model which includes the CDF mass anomaly and is consistent with the various observables at the Z pole and consistent with the ATLAS dilepton limits. The Stueckelberg Z' boson, which resolves the CDF W mass anomaly, should be searchable in future LHC experiments.

主讲人介绍：

刘佐伟，南京大学物理学院教授。2003年复旦大学本科毕业；2008年美国东北大学博士毕业；2008年至2011年在美国纽约州立大学石溪分校杨振宁理论物理研究所做博士后研究；2011年至2014年在加拿大麦吉尔大学做博士后研究；2014年至2016年在清华大学任副研究员；2016年至今在南京大学任教授。长期从事高能理论研究，研究方向包括暗物质理论和唯象学研究，加速器实验上寻找新物理的研究等。迄今发表学术论文41篇，引用2600余次，单篇最高引用328次。