PSL(2,7) Representations and their relevance to Neutrino Physics

The investigation of the role of finite groups in flavor physics and particularly, in the interpretation of the neutrino data has been the subject of intensive research. Motivated by this fact, in this work we derive the three-dimensional unitary representations of the projective linear group PSL_2(7). Based on the observation that the generators of the group exhibit a latin square pattern, we use available computational packages on discrete algebra to determine the generic properties of the group elements. We present analytical expressions and discuss several examples which reproduce the neutrino mixing angles in accordance with the experimental data.Comment: 21 pages, 3 figure

Towards a realistic Standard Model from D-brane configurations

Effective low energy models arising in the context of D-brane configurations with Standard Model (SM) gauge symmetry extended by several gauged abelian factors are discussed. The models are classified according to their hypercharge embeddings consistent with the SM spectrum hypercharge assignment. Particular cases are analyzed according to their perspectives and viability as low energy effective field theory candidates. The resulting string scale is determined by means of a two-loop renormalization group calculation. Their implications in Yukawa couplings, neutrinos and flavor changing processes are also presented.Comment: 22 pages, 12 EPS figures, some clarifications/references adde

Inverted neutrino mass hierarchies from U(1) symmetries

Motivated by effective low energy models of string origin, we discuss the neutrino masses and mixing within the context of the Minimal Supersymmetric Standard Model supplemented by a U(1) anomalous family symmetry and additional Higgs singlet fields charged under this extra U(1). In particular, we interpret the solar and atmospheric neutrino data assuming that there are only three left-handed neutrinos which acquire Majorana masses via a lepton number violating dimension-five operator. We derive the general form of the charged lepton and neutrino mass matrices when two different pairs of singlet Higgs fields develop non--zero vacuum expectation values and show how the resulting neutrino textures are related to approximate lepton flavor symmetries. We perform a numerical analysis for one particular case and obtain solutions for masses and mixing angles, consistent with experimental data.Comment: 15 pages, 4 figure

Modeling the Scientific Dimension of Academic Conferences

AbstractThe rapid spread of the Internet and the growing trend towards research are the leading factors and strong springboards, for the Industry of conference organizations, to proceed with further development. With the increase of shareholding in organizing events, the environment has become very complex. The Conference Organizing Committee is challenged to define a wide range of factors, in order to better serve the needs and objectives of the Conference.The main topic of this research is the study and modeling of the scientific dimension of Academic Conferences. We studied and recorded the basic procedures that govern the organization of scientific conferences. These are the procedures that affect the way that scientific conferences are conducted and eventually of course, the success or failure of those. Our research is engaged in the scientific aspect of these conferences, as the majority of the participants are scientifically renowned academics

Developmental Risk: Evidence from Large Nonrighthanded Samples

The aim of the present study is twofold. First, we tested the view that individuals who do not develop a typically strong behavioral laterality are distributed differentially among the two genders across age. Second, we examined whether left handedness and mixed handedness are associated with an elevated risk of some developmental or cognitive deficits. A special recruitment procedure provided norms of the Rey-Osterrieth Complex Figure (ROCF) copy from large samples of left-handed ( = 420) and mixedhanded ( = 72) compared to right-handed ( = 420) schoolchildren and adults ( = 545). This graphic task was considered as reflective of the growth of visual-spatial skills and impairment at copying as a developmental risk. Subjects' hand preference was assessed by the Edinburgh Handedness Inventory. Data analysis indicated that (1) the trend towards consistent right handedness is sex related. Girls are clearly ahead of boys in this lateralization process, and boys are overrepresented in mixed-handed subjects. The greater prevalence of mixed-handed boys compared to girls decreases with age. (2) Performance on drawing the ROCF varies according to age and handedness groups.Mixed-handed subjects scoredworse in all age groups.The results are discussed in relation to the hormonal-developmental, neuropathological, and learning theories of lateralization