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Neutral current in reduced minimal 3-3-1 model

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This work is devoted for gauge boson sector of the recently proposed model based on SU(3)C ⊗ SU(3)L ⊗ U(1)X group with minimal content of leptons and Higgses. The limits on the masses of the bilepton gauge bosons and on the mixing angle among the neutral ones are deduced. Using the Fritzsch anzats on quark mixing, we show that the third family of quarks should be different from the first two. We obtain a lower bound on mass of the new heavy neutral gauge boson as 4.032 TeV. Using data on branching decay rates of the Z boson, we can fix the limit to the Z and Z 0 mixing angle φ as −0.001 ≤ φ ≤ 0.0003. | Communications in Physics, Vol. 24, No. 2 (2014), pp. 97-112 NEUTRAL CURRENT IN REDUCED MINIMAL 3-3-1 MODEL VU THI NGOC HUYEN AND HOANG NGOC LONG Institute of Physics, Vietnam Academy of Science and Technology TRAN THANH LAM Department of Physics, Kien Giang Community College VO QUOC PHONG Department of Physics, Ho Chi Minh city University of Natural Science, Vietnam E-mail: hnlong@iop.vast.ac.vn Received 24 February 2014 Accepted for publication 04 April 2014 Abstract. This work is devoted for gauge boson sector of the recently proposed model based on SU(3)C ⊗ SU(3)L ⊗ U(1)X group with minimal content of leptons and Higgses. The limits on the masses of the bilepton gauge bosons and on the mixing angle among the neutral ones are deduced. Using the Fritzsch anzats on quark mixing, we show that the third family of quarks should be different from the first two. We obtain a lower bound on mass of the new heavy neutral gauge boson as 4.032 TeV. Using data on branching decay rates of the Z boson, we can fix the limit to the Z and Z 0 mixing angle φ as −0.001 ≤ φ ≤ 0.0003. Keywords: extended standard model. I. INTRODUCTION The experimental evidences of nonzero neutrino masses and mixing [1] have shown that the standard model (SM) of fundamental particles and interactions must be extended. Among many extensions of the SM known today, the models based on gauge symmetry SU(3)C ⊗ SU(3)L ⊗ U(1)X (so-called 3-3-1 models) [2,3] has interesting features. First, [SU(3)L ]3 anomaly cancellation requires that the number of SU(3)L fermion triplets must equal to that of antitriplets. If these multiplets are respectively enlarged from those of the SM, the fermion family number is deduced to be a multiple of the fundamental color number, which is three, coinciding with the observation. In addition, one family of quarks has to transform under SU(3)L differently from the other two. This can lead to an explanation why the top quark is uncharacteristically heavy. One of the weaknesses of