We evaluate the stellar energy-loss rates [Formula: see text] due to the production of neutrino pair in 3-3-1 models. The energy loss rate [Formula: see text] is evaluated for different values of [Formula: see text] in which [Formula: see text] is a parameter used to define the charge operator in the 331 models. We show that the contribution of dipole moment to the energy loss rate is small compared to the contribution of new natural gauge boson [Formula: see text]. The correction [Formula: see text] compared with that of Standard Model is evaluated and do not exceed 14% and is highest with [Formula: see text]. Of all the evaluated models, model with [Formula: see text] give a relative large [Formula: see text] correction for the mass of [Formula: see text][Formula: see text] GeV. This mass range is within the searching range for [Formula: see text] boson at LHC.

We re-investigate the scalar potential and the Higgs sector of the supersymmetric economical 3-3-1 model (SUSYE331) in the presence of the B/μ-type terms, which has many important consequences. First, the model contains no massless Higgs fields. Second, we prove that the soft mass parameters of the Higgses must be at the SU(3) L scale. As a result, the masses of the Higgses drift toward this scale except one light real neutral Higgs with the mass of m Z |c 2γ | at the tree level. We also show that there are some Higgses containing many properties of the Higgses in the minimal supersymmetric standard model (MSSM), especially in the neutral Higgs sector. One exact relation in the MSSM, m 2 H ± = m 2 A + m 2 W , is still true in the SUSYE331. Based on this result we make some comments on the lepton flavor violating decays of these Higgses as one of signatures of new physics in the SUSYE331 model which may be detected by present colliders.

We investigate the muon anomalous magnetic moment in the context of the supersymmetric version of the economical 3-3-1 model. We compute the 1-loop contribution of super-partner particles. We show that the contribution of superparticle loops become significant when tan γ is large. We investigate for both small and large values of tan γ. We find the region of the parameter space where the slepton masses are of a few hundreds GeV is favoured by the muon g − 2 for small tan γ (tan γ ∼ 5). Numerical estimation gives the mass of supersymmetric particle, the mass of gauginos m G ∼ 700 GeV and light slepton mass mL is of order O (100) GeV. When tan γ is large (tan γ ∼ 60), the mass of charged slepton mL and the mass of gauginos m G ∼ O(1) TeV while the mass of sneutrino ∼ 450 GeV is in the reach of LHC. * dtbinh@iop.vast.ac.vn † dthuong@iop.vast.ac.vn ‡ hnlong@iop.vast.ac.vn

The microstructure and mechanical properties of TiAl 3 /Al 2 O 3 in situ composite by combustion process are investigated in details. Pure Al powder and TiO 2 powder were mechanically milled with a molar ratio of 13 : 3 at 300 rpm for 18 ks. This milling powder's green compact coldpressed at 200 MPa for 0.3 ks sintered at 923 to 1173 K for 1.8 ks under Ar atmosphere. The microstructure of the sintered compact was identified by XRD, SEM and TEM/EDS. Mechanical properties were evaluated by Vickers hardness and indentation fracture toughness tests. The compacts at less than 973 K consist of a TiAl 3 phase and remained phases of Al and TiO 2 , while the compact at more than 1023 K consist of TiAl 3 matrix, dispersed Al 2 O 3 particles and some plate like Ti 3 Al phase. The compacts at more than 1023 K have the higher hardness around 800 Hv compared to TiAl 3 single phase compact with 450 Hv. The fracture toughness of TiAl 3 /Al 2 O 3 composite is about two times TiAl 3 single phase compact. This improvement of hardness and toughness is attributed to the effect of the microstructure formation of dispersed Al 2 O 3 particles and Ti 3 Al plate like phase in the TiAl 3 matrix.