Particle Physics Phenomenology On Supersymmetric Models

Particle physics phenomenology is a necessary part of high energy particle physics research.Between theoreticle research and high energy experimets,phenomenology forms a bridge by making numerical calculations and simulations on complex particle physics theories,and comparing the theoritical predictions with experimental results.Only by comparing various details between predictions and experiments can we know how to build and improve models,what parameters should be used for certain models,or how to fit parameters’ value to meet experimental results.The Standard Model is the best model that well tested and generally accepted.However,it still remains unsolved questions in Standard Model such as no dark matter particle candidate and serious fine tuning problem.These questions can be well explained in the supersymmetric model,so it is very meaningful to carry out phenomenological research on supersymmetric theory.In this thesis,phenomenological studies were conducted on two senarios that the lightest supersymmetric neutrallino act as dark matter particle.One is bino dominent neutralino in Minimal Supersymmetric Standard Model play the role of Dark Matter candidate with its mass less than 100GeV.By performing simulation on 14TeV LHC based on samples survived from scan and constraints,we found that:.With slepton heavier than 350GeV,x10 will mainly annihilate in two ways:1.mx10≌mz/2,x10 annihilate by s-channel exchange of Z boson.These samples has μ(?)470GeV,2.mx10≌mh/2,x10 annihilate by s-channel exchange of Higgs boson.For these samples μ(?)800GeV..For samples with ml(?)350GeV,t/u-channel mediation of light sleptons will play important role in annilation process of Dark Matter.· If no multi-lepton plus ETmiss signals observed at 14TeV LHC,data with 30fb-1,100fb-1,300fb-1 luminosity will limit mx1~0 over 43GeV,44GeV,55GeV.· Most samples with μ(?)350GeV and large split between μ and mx1~0 will be tested by 300fb-1 data..Most samples will be covered by the capability of future LZ-7.2T Dark Matter direct detection.The second senario is natural Next Minimal Supersymmetric Standard Model with its lightest neutralino being Dark Matter candidate.We limited both Az and △h lower than 50 during the scan and constrained outcome samples by monte carlo simulation.By investigated the impact of constraints from LUX-2016 Dark Matter direct search,we found:.Both △z and △h can remain low without conflicting with serious constraints.The natural Next Minimal Supersymmetric Standard Model is still natural..Restrictions on spin-dependent cross-sections are complementary to restrictions on spin-independent cross-sections.They both excluded many samples,especially ones with singlino dominant neutralino or higgsino dominant neutralino.· In the Next Minirmal Supersymmetric Standard Model,one can adjust different contributions to make spin-independent cross-section vanished.This will induce a new kind of fine tuning.Finally,after analysing problems,in developing programes of particle physical phe-nomenology,I introduced the toolkit,called ScanCraft,in Python framework.The pur-pose of developing this toolkit is to assist in the phenomenology research.Main principles of development are stated first,then two implement with different methods,including Markov chain scanning and multi-thread random scanning,were given.