In the simplest little Higgs model （SLH）, we study the spin correlations in the top quark pair production at the LHC and ILC. We find that the SLH always suppresses the tt spin correlations compared to the SM values...In the simplest little Higgs model （SLH）, we study the spin correlations in the top quark pair production at the LHC and ILC. We find that the SLH always suppresses the tt spin correlations compared to the SM values. At the LHC, the suppression can be over 10% for mz, 〈 750 GeV. The SLH prediction value is outside the 1σ range of the experimental data from ATLAS, and within 1σ range of the experimental data from CMS. At the ILC, the SLH can sizably suppress the tt spin correlation for mz, approaching the center-of-mass energy √s. For example, the maximal suppression can reach -22.5%, -14.5%, and -9.5% for √s = 500 Ge V, 800 Ge V, and 1000 GeV, respectively. Therefore, the tt spin correlation at the ILC can be a sensitive probe for the SLH.展开更多
We study prompt hadroproduction of the charged bottomonium-like states Zb± （10610） and Zb±（10650）, and the charged eharmonium-like states Zc± （3900） and Zc± （4020）, at the Tevatron and the ...We study prompt hadroproduction of the charged bottomonium-like states Zb± （10610） and Zb±（10650）, and the charged eharmonium-like states Zc± （3900） and Zc± （4020）, at the Tevatron and the LHC, provided that these states are S-wave hadronic molecules. Using two Monte Carlo event generators, Herwig and Pythia, to simulate the production of heavy meson pairs, we derive an order-of-magnitude estimate of the production rates for these four particles. Our estimates yield a cross section at the nb level for the Zb（10610） and Zb（10650）. The results for the Zc（3900） and Zc （4020） are larger by a factor of 2~30. These cross sections are large enough to be observed, and measurements at hadron colliders in the future will supplement the study using electron-positron collisions, and therefore allow to explore the mysterious nature of these exotic states.展开更多
Heavy-ion collisions at very high colliding energies are expected to produce a quark-gluon plasma(QGP) at the highest temperature obtainable in a laboratory setting. Experimental studies of these reactions can provide...Heavy-ion collisions at very high colliding energies are expected to produce a quark-gluon plasma(QGP) at the highest temperature obtainable in a laboratory setting. Experimental studies of these reactions can provide an unprecedented range of information on properties of the QGP at high temperatures. We report theoretical investigations of the physics perspectives of heavy-ion collisions at a future high-energy collider. These include initial parton production, collective expansion of the dense medium, jet quenching,heavy-quark transport, dissociation and regeneration of quarkonia, photon and dilepton production. We illustrate the potential of future experimental studies of the initial particle production and formation of QGP at the highest temperature to provide constraints on properties of strongly interaction matter.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos.11005089 and 11105116
文摘In the simplest little Higgs model （SLH）, we study the spin correlations in the top quark pair production at the LHC and ILC. We find that the SLH always suppresses the tt spin correlations compared to the SM values. At the LHC, the suppression can be over 10% for mz, 〈 750 GeV. The SLH prediction value is outside the 1σ range of the experimental data from ATLAS, and within 1σ range of the experimental data from CMS. At the ILC, the SLH can sizably suppress the tt spin correlation for mz, approaching the center-of-mass energy √s. For example, the maximal suppression can reach -22.5%, -14.5%, and -9.5% for √s = 500 Ge V, 800 Ge V, and 1000 GeV, respectively. Therefore, the tt spin correlation at the ILC can be a sensitive probe for the SLH.
基金Supported in part by the DFG and the NSFC through funds provided to the Sino-German CRC 110 ＂Symmetries and the Emergence of Structure in QCD＂, and by the NSFC under Grant No. 11165005
文摘We study prompt hadroproduction of the charged bottomonium-like states Zb± （10610） and Zb±（10650）, and the charged eharmonium-like states Zc± （3900） and Zc± （4020）, at the Tevatron and the LHC, provided that these states are S-wave hadronic molecules. Using two Monte Carlo event generators, Herwig and Pythia, to simulate the production of heavy meson pairs, we derive an order-of-magnitude estimate of the production rates for these four particles. Our estimates yield a cross section at the nb level for the Zb（10610） and Zb（10650）. The results for the Zc（3900） and Zc （4020） are larger by a factor of 2~30. These cross sections are large enough to be observed, and measurements at hadron colliders in the future will supplement the study using electron-positron collisions, and therefore allow to explore the mysterious nature of these exotic states.
基金the National Natural Science Foundation of China(Grant Nos.11175071,11221504,11305089,11322546,11375072,11435001 and 11435004)China MOST(Grant Nos.2014DFG02050 and2015CB856900)+5 种基金the Major State Basic Research Development Program in China(Grant Nos.2014CB845404 and 2014CB845403)the Natural Sciences and Engineering Research Council of Canadathe US National Science Foundation(Grant No.PHY-1306359)the Director,Office of Energy Research,Office of High Energy and Nuclear Physics,Division of Nuclear Physics,of the U.S.Department of Energy under Contract Nos.DE-AC02-05CH11231,DE-SC0012704within the framework of the JET CollaborationBJS is also supported by a DOE Office of Science Early Career Award
文摘Heavy-ion collisions at very high colliding energies are expected to produce a quark-gluon plasma(QGP) at the highest temperature obtainable in a laboratory setting. Experimental studies of these reactions can provide an unprecedented range of information on properties of the QGP at high temperatures. We report theoretical investigations of the physics perspectives of heavy-ion collisions at a future high-energy collider. These include initial parton production, collective expansion of the dense medium, jet quenching,heavy-quark transport, dissociation and regeneration of quarkonia, photon and dilepton production. We illustrate the potential of future experimental studies of the initial particle production and formation of QGP at the highest temperature to provide constraints on properties of strongly interaction matter.
