The CKM Matrix and Its Origin

In the context of the supersymmetric unification model in which the massless sector contains extra particles beyond those in the minimal supersymmetric standard model, we obtain mixings between quarks (leptons) and the extra particles which are closely intertwined with Yukawa hierarchies. With the assumption that the unification gauge group $G$ includes $SU(2)_R$, it is shown that the non-trivial texture of the CKM matrix originates from the extra-particle mixings. The CKM matrix of quarks emerges as a consequence of the mixings between the down-type quarks and colored Higgses, both of which are $SU(2)_L$-singlets. On the other hand, the CKM matrix of leptons is due to the mixings stemming from the seesaw mechanism with the hierarchical Majorana mass matrix of right-handed neutrinos.Comment: revised version, 18pages, Latex, no figures (to be published in Prog. Theor. Phys. Vol.100 No.1

Chamber Music of the 20th-Century Russians

The goal of my project was to further enhance my abilities as a collaborative pianist and take an in-depth look at two composers (Prokofiev and Shostakovich) who are strong influences in my love of music. I found the challenge to be in balancing all of my individual practice time with all of the rehearsals between the three separate groups. Each group met at least once a week for a two-hour rehearsal in addition to having weekly coachings with members of the Fry Street Quartet. In the end, the recital was an immense success and the program notes turned out nice. This project has really shown me what I am capable of as a musician, but more importantly, as a collaborator. I have strong hopes for a solid future in the world of piano

Quark CP-Phase and Froggatt-Nielsen Mechanism

On the basis of the Froggatt-Nielsen mechanism, we study quark flavor mixings in the $SU(6) \times SU(2)_R$ model. The characteristic structure of the CKM matrix is attributed to the hierarchical effective Yukawa couplings due to the Froggatt-Nielsen mechanism and also to the state-mixings beyond the MSSM. We elucidate the detailed form of the CKM matrix elements and find interesting relations between the \textit{CP} violating phase and three mixing angles. Taking the existing data of three mixing angles, we estimate the quark \textit{CP}-phase at $\delta = (75 \pm 3)^{\circ}$. This result is in accord with observations.Comment: 14 pages, no figure. To be published in Physics Letters B. Several sentences are added. arXiv admin note: text overlap with arXiv:1210.376

The String Unufication of Gauge Cuoplings and Gauge Kinetic Mixings

In the superstring models we have not only the complete {\bf 27} multiplets of $E_6$ but also extra incomplete $({\bf 27}+{\overline {\bf 27}})$ chiral supermultiplets being alive at low energies. Associated with these additional multiplets, when the gauge symmetry contains more than one $U(1)$ gauge group, there may exist gauge kinetic mixings among these $U(1)$ gauge groups. In such cases the effect of gauge kinetic mixings should be incorporated into the study of unification of gauge couplings. We study these interesting effects systematically in these models. The string threshold effect is also taken into account. It is found that in the four-generation models we do not have a advisable solution of string unification of gauge couplings consistent with experimental values at the electroweak scale. We also discuss the possible scenarios to solve this problem.Comment: 27 pages, LaTeX, DPNU-93-16, AUE-03-9

The Aligned SU(5)×U(1)2SU(5) \times U(1)^2 Model

In Calabi-Yau string compactification, it is pointed out that there exists a new type of $SU(5) \times U(1)^2$ model (the aligned $SU(5) \times U(1)^2$ model) in which the $SU(5)$ differs from the standard $SU(5)$ and also from the flipped $SU(5)$. With the aid of the discrete symmetry suggested from Gepner model, we construct a simple and phenomenologically interesting three-generation model with the aligned $SU(5) \times U(1)^2$ gauge symmetry. The triplet-doublet splitting problem can be solved. It is also found that there is a realistic solution for solar neutrino problem and for the $\mu$-problem. At low energies this model is in accord with the minimal supersymmetric standard model except for the existence of singlet fields with masses of $O(1)$TeV.Comment: LaTeX 24 page

Students with dyslexia: research projects at Northumbria University

Northumbria University has about 700 registered disabled students, the majority of whom (around 58 per cent) are registered as having dyslexia and account for approximately two per cent of the total student population. Therefore dyslexic students represent the largest single group of disabled students and are those with whom most staff are likely to come into contact. The research authors were keen to ascertain whether there was a difference in academic performance between dyslexic and non-dyslexic students in respect of degree classification and assignment marks and to investigate whether dyslexic students generally felt supported in their academic studies. Research involved both qualitative and quantitative strands and the areas explored include pre expectations; general support throughout study; methods, flexibility and clarity of learning tasks, in particular assessment and levels of performance throughout and at the end of their study. This research is ongoing, however, findings have proved invaluable as a basis in the construction of good practice guidelines in dealing with the pedagogic needs of this diverse student grou

Precocious Gauge Symmetry Breaking in SU(6)×SU(2)RSU(6) \times SU(2)_R Model

In the $SU(6) \times SU(2)_R$ string-inspired model, we evolve the couplings and the masses down from the string scale $M_S$ using the renormalization group equations and minimize the effective potential. This model has the flavor symmetry including the binary dihedral group $\tilde{D}_4$. We show that the scalar mass squared of the gauge non-singlet matter field possibly goes negative slightly below the string scale. As a consequence, the precocious radiative breaking of the gauge symmetry down to the standard model gauge group can occur. In the present model, the large Yukawa coupling which plays an important role in the symmetry breaking is identical with the colored Higgs coupling related to the longevity of the proton.Comment: 15 pages, 2 figure

Semidirect product gauge group [SU(3)c×SU(2)L]⋊U(1)Y[SU(3)_{\rm c} \times SU(2)_{\rm L}]\rtimes U(1)_{\rm Y} and quantization of hypercharge

In the Standard Model the hypercharges of quarks and leptons are not determined by the gauge group $SU(3)_{\rm c} \times SU(2)_{\rm L} \times U(1)_{\rm Y}$ alone. We show that, if we choose the semidirect product group $[SU(3)_{\rm c} \times SU(2)_{\rm L}] \rtimes U(1)_{\rm Y}$ as its gauge group, the hyperchages are settled to be $n/6 \mod {\mathbb{Z}}\;(n = 0,1,3,4)$. In addition, the conditions for gauge-anomaly cancellation give strong constraints. As a result, the ratios of the hypercharges are uniquely determined and the gravitational anomaly is automatically canceled. The standard charge assignment to quarks and leptons can be properly reproduced. For exotic matter fields their hypercharges are also discussed.Comment: 17 pages, 2 tables; LaTeX; typos corrected, references added or replaced, argument in Secs. 2 and 3 revised, results unchanged; to be published in Phys. Rew.