Dissertation > Mathematical sciences and chemical > Physics > Nuclear physics,high energy physics > High-energy physics > Particle physics

The Study of T~--→e~-P~0(PP) Decays in R-Parity Violating Supersymmetry

Author GaoSuZhi
Tutor LiWenJun
School Henan Normal
Course Theoretical Physics
Keywords τ lepton Lepton flavor breaking R - parity breaking supersymmetric model Chiral perturbation theory
CLC O572.2
Type Master's thesis
Year 2011
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Lepton flavor breaking (LFV) is a research project of the new physics. In the standard model, the lepton number is conserved, even if the tiny mass of the neutrino is taken into account, the occurrence probability is negligible lepton flavor breaking, so, if part of the observed charged lepton to lepton flavor breaking lack of the phenomenon, which will be a significant sign of the existence of new physics. three generations of charged lepton τ is the largest in the quality, more lepton flavor breaking decay channels than μ and e are more sensitive to new physics, study lepton flavor preferred particle breaking. Current and τ lepton lepton flavor breaking decay process: τ radiative decay τ-→ e-γ, pure light decay τ-→ e ee-semileptonic decay τ → eM (e = μ , e; M = Po, V0, PP). Belle and BaBar experiment group of these processes to detect these decay process experimental upper limit of O (10-8-10-7), and f-→ e-π0π0. The branching ratio of the decay process the CLEO experimental group detection experimental upper limit is O (10-6-10-5). B factories and τ factories a 901fb-1 integrated luminosity of the experimental data has been a lot of τ decay, breaking to provide a lot of experimental evidence for the study of lepton flavor. Theoretically, it is also beyond the new physical model of the standard model of these decay process a lot of research related to the new physical model topcolor model, SUSY-seesaw model, the minimal supersymmetric model (MSSM), double Higgs doublet (2HDM) model, R-parity breaking supersymmetric model (RPV SUSY), Technicolor model, LHT model, etc.. , R-parity breaking supersymmetric model is one of the most attractive new physical model. R-parity breaking supersymmetric model τ-→ e-P0 (π0, η, η ') and τ-→ e-PP (π0π0, π π-K K-K0K0) decay process, where e = e, μ. In this model, the decay process by sneutrino and squark propagator at the level of the tree diagram. Τ-→ e-P0 and τ-→ e-PP decay process of the final state hadronic matrix element, we have adopted the approach of chiral perturbation theory and resonance chiral theory. The calculation results show that the vector resonance τ-→ e-PP process does not contribute. We use the BR (τ-→ e-P0) and BR (τ-→ e-PP) experimental upper limit of the model coupling parameter product | λ'λ | and | λ '* λ' | 2010 Belle experimental group announced restrictions to 10-4 order of magnitude, consistent with the literature results. We compared the mf = 1 00GeV Lie (μ) = 10-3, the size of the various decay branching ratio level relationship. BR (τ-→ e-π0π0) process only v pass the contribution of the scalar stream; process of BR (τ-→ e-π π-) q contribution than the contribution of v, on the other process, the contribution of v q. contribution. We also take advantage of the current experimental branch ceiling limits the space (Lie-mf): mf ∈ (100 - 1000) GeV, Lle (μ) to LSe (μ) range (10-4 to 10 - 2). Our results of experiments probing LFV and distinguish between different model reference.

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