Phenomenology Of New Physics About Some Processes At The LHC And ILC

Technicolor and little Higgs are important candidates of new physics beyond the standardmodel, they not only expand and enrich the standard model from various aspects, but alsobring many new ideas, which will act pivotal roles on the realization of the unified descriptionof fundamental interactions. These models predict some new particles, such as the pseudoGoldstone bosons (PGBs), top-Higgs boson and new gauge bosons in the topcolor assistedtechnicolor (TC2), and the new heavy gauge bosons, heavy fermions and heavy scalar particlesin the littlest Higgs model with T parity (LHT), which can be regarded as typical features ofthese two models. Whether these particles exist or not, it is an important content testing theSM and beyond.Basing on the running large hadron collider (LHC) and the planning international linearcollider (ILC), we analyse the conceivable e?ects of new particles in the TC2 and LHT modelsto some processes, which include the following aspects:(1) We have calculated the technicolor corrections to the cross section for W±π?t associatedproduction via bˉb annihilation at the CERN LHC in the topcolor assisted technicolor model, andfind that, the total cross section of pp→bˉb→W±π?t at the tree level, is roughly correspondingto that of the process pp→bˉb→W±H in the minimal supersymmetric standard model(MSSM), and can reach a few hundreds fb with reasonable values of the parameters. Consideringthe technicolor corrections arising from the one-loop diagrams, the relative correction is abouta few percent to two dozen percent.(2) We have studied the associated production processes of a neutral top-Higgs in the TC2model with a pair of heavy quarks inγγcollisions at the ILC, and find that the cross section forttˉht0 inγγcollisions is at the level of 1 fb with the c.m. energy√s = 1000 GeV, which coincideswith the results of the cross section of ttˉH in the SM, of ttˉh0 in the MSSM, and of ttˉh in theLHT. Because ht0 is also a scalar particle, we need to a?rm which model it is from if the ILCexperiment could detect a scalar particle, which will further require more experimental data and theoretical analysis.(3) We have also investigated the one-loop corrections to theγγ→bˉb corss section inthe topcolor assisted technicolor models and the littlest Higgs model with T parity at thephoton-photon colliders. We find that, in TC2 models, for the favorable parameters, the relativecorrections from pseudo Goldstone bosons give out a 3.2%～5.9% decrement of the cross sectionfrom the tree level, the contributions from new extended technicolor gauge bosons Z? and coloredtopcolor gauge bosons B are negligibly small, and the relative correction arising from new color-singlet heavy topcolor gauge boson Z is less than ?3.2%; and in LHT model, the total crosssectionσ(e+e?→γγ→bˉb) is sensitive to the breaking scale f, mixing parameter xL, themasses of the mirror quarks mHi, and the relative correction of the LHT model is a few percentto dozens of percent. However, the contribution of Higgs boson in the SM is only the order of10?5 which is negligibly small, the relative correction induced by the charged Higgs and chargedGoldstone bosons in the 2HDM and MSSM is less than 0.1%. Therefore, the processγγ→bˉbis rather sensitive to the e?ects of new physics, and its cross section is the order of pb, whichmeans millions of the bottom pairs per year can be produced at the future ILC.We hope that the LHC would like to detect the charged top-pion in order to directly searchthe signals of topcolor assisted technicolor. In the same way, we expect that the number ofthe pair of b quark could be accurately measured in high-energy photon-photon collision at thefuture ILC, it will be interesting to indirectly compare the e?ects of various new physics.