CP Violation in Λb → Λł+ł-Decay in the Four–Generation Standard Model
V. Bashiry1, N. Shirkhanghah2, K. Zeynali3,4
1Engineering Faculty, Cyprus International University,ViaMersin 10, Turkey2Islamic Azad University, Khalkhal Branch, Valiasr St., Khalkhal, Iran3Department of Sciences, Ardabil University of Medical Sciences,Daneshgah St., Ardabil Iran4Faculty of Physics, University of Tabriz, Tabriz 51664, Iran
CP Violation in Λb → Λł+ł-Decay in the Four–Generation Standard Model
V. Bashiry1, N. Shirkhanghah2, K. Zeynali3,4
1Engineering Faculty, Cyprus International University,ViaMersin 10, Turkey2Islamic Azad University, Khalkhal Branch, Valiasr St., Khalkhal, Iran3Department of Sciences, Ardabil University of Medical Sciences,Daneshgah St., Ardabil Iran4Faculty of Physics, University of Tabriz, Tabriz 51664, Iran
We present the first study of CP asymmetry in Λb →Λ decay when a new weak phase comes through the extension of three-generation standard model to the four-generation standard model. Taking =0.01,0.02,0.03 with phase {60°-120°}, which is consistent with therate and the Bs mixing parameter ΔmBs, we find out that CP asymmetry is quite sensitive to the existence of fourth generation. It can serve as a good tool to search for new physics effects, in particular, to search for the fourth generation quarks (t', b') via their indirect manifestations in loop diagrams.
We present the first study of CP asymmetry in Λb →Λ decay when a new weak phase comes through the extension of three-generation standard model to the four-generation standard model. Taking =0.01,0.02,0.03 with phase {60°-120°}, which is consistent with therate and the Bs mixing parameter ΔmBs, we find out that CP asymmetry is quite sensitive to the existence of fourth generation. It can serve as a good tool to search for new physics effects, in particular, to search for the fourth generation quarks (t', b') via their indirect manifestations in loop diagrams.
V. Bashiry;N. Shirkhanghah;K. Zeynali;. CP Violation in Λb → Λł+ł-Decay in the Four–Generation Standard Model[J]. 中国物理快报, 2010, 27(4): 41201-041201.
V. Bashiry, N. Shirkhanghah, K. Zeynali,. CP Violation in Λb → Λł+ł-Decay in the Four–Generation Standard Model. Chin. Phys. Lett., 2010, 27(4): 41201-041201.
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2010, Vol. 27 
decay when a new weak phase comes through the extension of three-generation standard model to the four-generation standard model. Taking 
=0.01,0.02,0.03 with phase {60°-120°}, which is consistent with the
rate and the Bs mixing parameter ΔmBs, we find out that CP asymmetry is quite sensitive to the existence of fourth generation. It can serve as a good tool to search for new physics effects, in particular, to search for the fourth generation quarks (t', b') via their indirect manifestations in loop diagrams. 
=0.01,0.02,0.03 with phase {60°-120°}, which is consistent with the
rate and the Bs mixing parameter ΔmBs, we find out that CP asymmetry is quite sensitive to the existence of fourth generation. It can serve as a good tool to search for new physics effects, in particular, to search for the fourth generation quarks (t', b') via their indirect manifestations in loop diagrams.