The W mass determination at the Tevatron CDF experiment reported a deviation from the SM expectation at the 7σlevel.We discuss a few possible interpretations and their collider implications.We perform electroweak glo...The W mass determination at the Tevatron CDF experiment reported a deviation from the SM expectation at the 7σlevel.We discuss a few possible interpretations and their collider implications.We perform electroweak global fits under various frameworks and assumptions.We consider three types of electroweak global fits in the effective-field-theory framework:the S-T,S-T-δG_(F),and eight-parameter flavor-universal one.We discuss the amounts of tensions between different m_(W)measurements reflected in these fits and the corresponding shifts in central values of these parameters.With these electroweak fit pictures in hand,we present a few different classes of models and discuss their compatibility with these results.We find that while explaining the m_(W)discrepancy,the single gauge boson extensions face strong LHC direct search constraints unless the Z′is fermiophobic(leptophobic),which can be realized if extra vector fermions(leptons)mix with the SM fermions(leptons).Vector-like top partners can partially generate the needed shift to the electroweak observables.The compatibility with the top squark is also studied in detail.We find that the non-degenerate top squark soft masses enhance the needed operator coefficients,enabling an allowed explanation compatible with current LHC measurements.Overall,more theoretical and experimental developments are highly in demand to reveal the physics behind this discrepancy.展开更多
基金supported by the National Natural Science Foundation of China (NNSFC)(12035008)supported in part by the U.S. Department of Energy (DOE)(DE-SC0022345)+7 种基金supported by"Study in Israel"Fellowship for Outstanding Post-Doctoral Researchers from ChinaPBC of CHE from Indiapartially supported by grants from the NSF-BSF (2018683)the ISF (482/20)the Azrieli foundationsupported by the NSFC (12025507, 12150015, 12047503)the Strategic Priority Research Program and Key Research Program of Frontier Science of the Chinese Academy of Sciences (XDB21010200, XDB23010000, ZDBSLY-7003)CAS project for Young Scientists in Basic Research (YSBR-006)
文摘The W mass determination at the Tevatron CDF experiment reported a deviation from the SM expectation at the 7σlevel.We discuss a few possible interpretations and their collider implications.We perform electroweak global fits under various frameworks and assumptions.We consider three types of electroweak global fits in the effective-field-theory framework:the S-T,S-T-δG_(F),and eight-parameter flavor-universal one.We discuss the amounts of tensions between different m_(W)measurements reflected in these fits and the corresponding shifts in central values of these parameters.With these electroweak fit pictures in hand,we present a few different classes of models and discuss their compatibility with these results.We find that while explaining the m_(W)discrepancy,the single gauge boson extensions face strong LHC direct search constraints unless the Z′is fermiophobic(leptophobic),which can be realized if extra vector fermions(leptons)mix with the SM fermions(leptons).Vector-like top partners can partially generate the needed shift to the electroweak observables.The compatibility with the top squark is also studied in detail.We find that the non-degenerate top squark soft masses enhance the needed operator coefficients,enabling an allowed explanation compatible with current LHC measurements.Overall,more theoretical and experimental developments are highly in demand to reveal the physics behind this discrepancy.
