Summary of the Phd thesis Theoretical and mathematical physics: The 3-3-1 simple model and the 3-2-2-1 model for dark matter and neutrino masses

The purposes of research: Searching of dark matter in the proposed model called the simple 3-3-1 model (S331M); solving the neutrino mass problem and determine the Higgs spectrum in the G221 model with lepton-flavor non-universality.
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Summary of the Phd thesis Theoretical and mathematical physics: The 3-3-1 simple model and the 3-2-2-1 model for dark matter and neutrino massesMINISTRY OF EDUCATION VIETNAM ACADEMY OF SCIENCE AND TRAINING AND TECHNOLOGY GRADUATE UNIVERSITY SCIENCE AND TECHNOLOGY ……..….***………… NGUYEN THI KIM NGAN SIMPLE 3-3-1 MODEL AND 3-2-2-1 MODEL FOR DARK MATTER AND NEUTRINO MASSES Speciality: Theoretical and mathematical physics Code: 62 44 01 03 SUMMARY OF THE PHD THESIS Hanoi – 2018 This thesis was completed at Graduate University of Science and Technology, Vietnam Academy of Science and Technology.Supervisors: Dr. Phung Van Dong Prof. Hoang Ngoc LongReferee 1: Prof. Dang Van SoaReferee 2: Dr. Dinh Nguyen DinhReferee 3: Dr. Tran Minh HieuThis dissertation will be defended in front of the evaluating assembly atacademy level, place of defending: meeting room, Graduate Universityof Science and Technology, Vietnam Academy of Science andTechnology.This thesis can be studied at:- The Library of Graduate University of Science and Technology- The Vietnam National Library 1INTRODUCTION The Standard Model (SM) has been successful in exactly pre-dicting many observational experimental results. Successes of SMcan be mentioned such as predicting the Z and W boson, gluons,c (charm) quark, t (top) quark and b (bottom) quark before theywere observed by the experiments. One of those is prediction ofHiggs boson recently discovered by LHC (Large Hadron Collider)at CERN with the 125 GeV mass. This is the last particle predictedby SM. However, to this day there are much experimental data re-maining beyond prediction of SM, such as: • Why does t (top) quark have the uncommon heavy mass? SM predicted t quark has the approximate 10 GeV mass while the experimental result of Tevatron at Fermilab in 1995 demon- strated that t quark has the 173 GeV mass. • The early universe is a quantum system, therefore the number of particles equals to the one of anti-particles, why the present universe only includes matter constituted by particles, there is no evidence for the existence of antimatter structured by anti-particles, called matter-antimatter asymmetry or baryon asymmetry. • SM predicted neutrinos have zero masses because they do not have the right-handed components and lepton number is conserved. However, the solar, atmospheric, accelerator and reactor neutrino experiments have predicated in most of 20 years that there are neutrino ocillations when they propa- gate a long enough journey. This requires neutrinos to have nonzero masses (even if they are smaller than 1 eV) and mix- ing. There are three flavours of neutrinos and their mixing parameterise through the three Euler angles and three CP vi- olation phases (1 Dirac phase and 2 Majorana phases). The 2 existing data of the recent experiments have showed that the squared mass differences and the mixing angles of neutrinos have their defined values. There is large mixing between the electron neutrino and the muon neutrino, between the muon neutrino and the tau neutrino, while there is small mixing (different to zero) between the electron neutrino and the tau neutrino. This is completely different from the quark mixing (all of them are small). The neutrino experiments can just determine the Dirac phase which can be different to zero and can not define the Majorana phases. Then, are the neutrinos Dirac or Majorana fermions? How can generate the naturally small neutrino masses which are appropriate for the exper- imental data? why does the flavour mixing of quarks and leptons have the completely determined mixing angles? If there is the existence of right-handed neutrinos νaR they are colorless, null isospin and null weak hypercharge. Thus, they do not have gauge interactions, called sterile particles. How- ever, they can be meaningful in generating neutrino masses and in the baryon number asymmetry of the universe. In fact, when νaR is added neutrinos can get Dirac masses because of the interaction with the Higgs boson, mD ∼ v (electroweak scale), which is similar to the charged fermions. Because νaR is the singlet of SM they can get large Majorana masses, mR , which violate lepton number. As a result, the active neutri- nos ∼ νaL gain Majorana masses by the seesaw mechanism, mL = −(mD )2 /mR , which is naturally small because of the condition mR mD . It is similar to The Grand Unified The- ory (GUT) SO(10) that the Dirac masses are proportional to the electroweak scale, mD ∼ 100 GeV. The active neutrinos mL ∼ eV , then m ...