Multiplicity Dependence Of K_S⁰, Λ And Λ Production In Proton-proton Collisions At S^-1/2=7TeV

"One foot of the whip, day take the half, eternally inexhaustible." This ancient Chinese phrase shows us a rather simple truth:for all the history of humankind, people try their best to uncover the mist of the natural beings, yet it still remains mystery. Thanks for our former scientists we now know that natural matter is composed of molecules that are composed of atoms. And nucleons (protons, neutrons) and electrons form atoms. That is all we know till20th Century. With new technology, high energy colliders are built and more particles are discovered. Now we know that nucleons are composed of quarks and gluons,."Standard Model" of particle physics is developed to describe a wide variety of experimental results successfully. However,it is not the ultimate theory for sure. Some problems are beyond its explanations, such as the mass of Higgs boson, super symmetry particles, the neutrino mass puzzle and so on. According to the LQCD theory, we know that quarks and gluons are confined in hadrons but in high-temperature and high-density conditions, the quark confinement should be broken and form a new phase named quark-gluon plasma(QGP).One of the main purpose of heavy-ion physics is to approve the existence of QGP and to study its properties.Experimentally, QGP can only be detected indirectly.There are many signals that we could use as "Probes" for the QGP study. Jet-quenching, Collective flow, and strangeness enhancement are all good probes. Besides, as we will find out latter, baryon-meson ratio is expected to give us some import information about QGP.Experiments at the Relativistic Heavy Ion Collider(RHIC) at Brookhaven National Laboratory(BNL) have already published many results on the existence of QGP. A large Ion Collision Experiment(ALICE) at LHC(CERN) experiment has shown additional evidence on the existence of QGP. In this paper, we measured the multiplicity dependence of Ks0, A and (?) production in proton-proton collision at s=7TeV. We find that the yields and mean transverse momenta increase with multiplicity. The (A+A)/Ks0ratio at intermediate PT increases with multiplicity and the peak position shifts towards higher PT.