The new measurement of the W boson mass from the CDF collaboration shows a significant tension with the standard model prediction,which evidences violation of custodial symmetry in the scalar sector.We study the scala...The new measurement of the W boson mass from the CDF collaboration shows a significant tension with the standard model prediction,which evidences violation of custodial symmetry in the scalar sector.We study the scalar extensions of the standard model,which can be categorized into two classes,the scalar sector with custodial symmetry(Georgi-Machacek model and its generalizations)and the scalar sector without custodial symmetry,and explore how these extensions fit to electroweak precision data and the new CDF mW.The favored oblique parameters originate from either the large mass splitting in the multiplet via the loop contribution or the large vacuum expectation value,which breaks custodial symmetry at the tree level.In particular,we find that O(100)GeV new particles are allowed in the scalar extension scenarios.展开更多
基金the Fundamental Research Funds for the Central Universities of China(GK202003018)J.-H.Y.is supported by the National Science Foundation of China(12022514,11875003,and 12047503)+2 种基金the National Key Research and Development Program of China(2020YFC2201501,2021YFA0718304)the CAS Project for Young Scientists in Basic Research(YSBR-006)the Key Research Program of the CAS(XDPB15)。
文摘The new measurement of the W boson mass from the CDF collaboration shows a significant tension with the standard model prediction,which evidences violation of custodial symmetry in the scalar sector.We study the scalar extensions of the standard model,which can be categorized into two classes,the scalar sector with custodial symmetry(Georgi-Machacek model and its generalizations)and the scalar sector without custodial symmetry,and explore how these extensions fit to electroweak precision data and the new CDF mW.The favored oblique parameters originate from either the large mass splitting in the multiplet via the loop contribution or the large vacuum expectation value,which breaks custodial symmetry at the tree level.In particular,we find that O(100)GeV new particles are allowed in the scalar extension scenarios.
