LHC RUn1对SUSY的限制以及ATLAS PEAK超出迹象的研究.docx

AbstractThe Abstract The Standard Model(SM)is the most successful theory model in particle physics far and many observed data by experiments is consistent with its expectation．Furthermore，some particles such top quark and the Higgs boson were found by experiments successively,which were predicted by the property of symmetry in the SM．But the SM is not the ultimate theory that could explain all properties of nature and there are still some problems in itself．For example，the SM-like Higgs with mass near 126 GeV WaS found by the ATLAS and CMS cooperations and this improved the framework of the SM and explained the origin of maSs，i．e．， particles get their masses by the spontaneous symmetry breaking of the Higgs field．However， this followed problem that the SM could not explain why the mass of the Dew discovered Higgs is 126GeV by itself．In addition，the SM could not unify the fundamental interactions together give the proper candidate for the dark matter which constitutes about 21％of the universe． In order to solve these problems above，physicists developed kinds of new physics models and supersymmetry(SUSY)is of the most interesting new physical models．Physicists urgently hope that new particles predicted by supersymmetry could be discovered by collider experiments．Since the of LEP，phy’sicists had started to search for new physics，especially supersymmetry．But new particles are found by experiments far that supersymmetry is limited．For example，LEP had excluded the chargino mass to O(100GeV)．Along with LHC running since 2010，we expected that new particles would bc discovered during the of LHC． Excitingly there was significant result during the LHC Run-I that the Higgs particle Was discovered，whose mass is near 126GeV．However，there were other discoveries of new particles．、Absence of discoveries of new supersymmetric particles brought much strong limits on supersymmetry．For instance，the LHC Run-I had excluded the mass of gluino to O(1TeV)， the masses of stop and sbottom to O