In this talk we briefly summarise our recent study(hep-ph/0007165)on searching fortop squark at hadron colliders.The light top-squark(stop)if produced in hadron colliders in theform of the (?)(?) pair and decaying thr...In this talk we briefly summarise our recent study(hep-ph/0007165)on searching fortop squark at hadron colliders.The light top-squark(stop)if produced in hadron colliders in theform of the (?)(?) pair and decaying through the likely decay chain (?)→(?)+b followed展开更多
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
Searching for the top squark(stop)is a key task to test the naturalness of SUSY.Different from stop pair production,single stop production relies on its electroweak properties and can provide some unique signatures.Fo...Searching for the top squark(stop)is a key task to test the naturalness of SUSY.Different from stop pair production,single stop production relies on its electroweak properties and can provide some unique signatures.Following the single production process pp→t^(~)1X(~)1→tX^(~)1^(0)X^(~)1^(-),the top quark has two decay channels:leptonic channel and hadronic channel.In this paper,we probe the observability of these two channels in a simplified minimal supersymmetric standard model scenario.We find that,at the 27 TeV LHC with the integrated luminosity of L=15 ab^(-1),mt^(-)1<1900 GeV andμ<750 GeV can be excluded at 2σthrough the leptonic mono-top channel,while m_(t^(-)1)<1200 GeV andμ<350 GeV can be excluded at 2σthrough the hadronic channel.展开更多
文摘In this talk we briefly summarise our recent study(hep-ph/0007165)on searching fortop squark at hadron colliders.The light top-squark(stop)if produced in hadron colliders in theform of the (?)(?) pair and decaying through the likely decay chain (?)→(?)+b followed
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.
基金This work was supported by the National Natural Science Foundation of China(NNSFC)under Grant No.11705093by the Jiangsu Planned Projects for Post-doctoral Research Funds,Grant No.2019K197.
文摘Searching for the top squark(stop)is a key task to test the naturalness of SUSY.Different from stop pair production,single stop production relies on its electroweak properties and can provide some unique signatures.Following the single production process pp→t^(~)1X(~)1→tX^(~)1^(0)X^(~)1^(-),the top quark has two decay channels:leptonic channel and hadronic channel.In this paper,we probe the observability of these two channels in a simplified minimal supersymmetric standard model scenario.We find that,at the 27 TeV LHC with the integrated luminosity of L=15 ab^(-1),mt^(-)1<1900 GeV andμ<750 GeV can be excluded at 2σthrough the leptonic mono-top channel,while m_(t^(-)1)<1200 GeV andμ<350 GeV can be excluded at 2σthrough the hadronic channel.
