Physics Commons^™

Su(5) Grand Unification On A Domain-Wall Brane From An E_6-Invariant Action, Aharon Davidson, Damien P. George, Archil Kobakhidze, Raymond R. Volkas, Kameshwar C. Wali

Physics - All Scholarship

An SU(5) grand unification scheme for effective 3+1-dimensional fields dynamically localised on a domain-wall brane is constructed. This is achieved through the confluence of the clash-of-symmetries mechanism for symmetry breaking through domain-wall formation, and the Dvali-Shifman gauge-boson localisation idea. It requires an E_6 gauge-invariant action, yielding a domain-wall solution that has E_6 broken to differently embedded SO(10) x U(1) subgroups in the two bulk regions on opposite sides of the wall. On the wall itself, the unbroken symmetry is the intersection of the two bulk subgroups, and contains SU(5). A 4+1-dimensional fermion family in the 27 of E_6 gives rise …

Baryons And Mesons With Beauty, Goldstein R. Gary, Kameshwar C. Wali

Physics - All Scholarship

Recent experimental findings of several mesons and baryons with "beauty" and "charm" as flavors remind us of the days when strangeness was discovered, and how its inclusion led to SU(3)-flavor symmetry with enormous success in the classification of the "proliferated" states into SU(3) multiplets. One of the key elements was the successful application of the first order perturbation in symmetry breaking, albeit what then appeared to be huge mass differences, and the prediction of new states that were confirmed by experiments. In this note, we venture into the past and, applying the same techniques, predict some new "beauty-" and "charm-" …

The Clash Of Symmetries In A Randall-Sundrum-Like Spacetime, Gareth Dando, Aharon Davidson, Damien P. George, Raymond R. Volkas, Kameshwar C. Wali

Physics - All Scholarship

We present a toy model that exhibits clash-of-symmetries style Higgs field kink configurations in a Randall-Sundrum-like spacetime. The model has two complex scalar fields Phi_{1,2}, with a sextic potential obeying global U(1)xU(1) and discrete Phi_1Phi_2 interchange symmetries. The scalar fields are coupled to 4+1 dimensional gravity endowed with a bulk cosmological constant. We show that the coupled Einstein-Higgs field equations have an interesting analytic solution provided the sextic potential adopts a particular form. The 4+1 metric is shown to be that of a smoothed-out Randall-Sundrum type of spacetime. The thin-brane Randall-Sundrum limit, whereby the Higgs field kinks become step functions, …

The Higgs Sector On A Two-Sheeted Space Time, Cosmin Macesanu, Kameshwar C. Wali

Physics - All Scholarship

We present a general formalism based on the framework of non-commutative geometry, suitable to the study the standard model of electroweak interactions, as well as that of more general gauge theories. Left- and right-handed chiral fields are assigned to two different sheets of space-time (a discretized version of Kaluza-Klein theory). Scalar Higgs fields find themselves treated on the same footing as the gauge fields, resulting in spontaneous symmetry breaking in a natural and predictable way. We first apply the formalism to the Standard Model, where one can predict the Higgs mass and the top Yukawa coupling. We then study the …

Domain Wall Solutions With Abelian Gauge Fields, J. S. Rozowsky, R. R. Volkas, K. C. Wali

Physics - All Scholarship

We study kink (domain wall) solutions in a model consisting of two complex scalar fields coupled to two independent Abelian gauge fields in a Lagrangian that has $U(1)\times U(1)$ gauge plus $\mathbb{Z}_2$ discrete symmetry. We find consistent solutions such that while the U(1) symmetries of the fields are preserved while in their respective vacua, they are broken on the domain wall. The gauge field solutions show that the domain wall is sandwiched between domains with constant magnetic fields.

Clash Of Symmetries On The Brane, Aharon Davidson, B. F. Toner, R. R. Volkas, K. C. Wali

Physics - All Scholarship

If our 3 + 1-dimensional universe is a brane or domain wall embedded in a higher dimensional space, then a phenomenon we term the “clash of symmetries” provides a new method of breaking some continuous symmetries. A global

Gcts ⊗ Gdiscrete symmetry is spontaneously broken to Hcts ⊗ Hdiscrete, where the continuous subgroup Hcts can be embedded in several different ways in the parent group Gcts, and Hdiscrete < Gdiscrete. A certain class of topological domain wall solutions connect two vacua that are invariant under differently embedded Hcts subgroups. There is then enhanced symmetry breakdown to the intersection of these two subgroups on the domain wall.This is the “clash”. In the brane limit, we obtain a configuration with Hcts symmetries in the bulk but the smaller intersection symmetry on the brane itself. We illustrate this idea using a permutation symmetric three-Higgstriplet toy model exploiting the distinct I−, U− and V − spin U(2) subgroups of U(3). The three disconnected portions of the vacuum manifold can be treated symmetrically through the construction of a three-fold planar domain wall junction configuration, with our universe at the nexus. A possible con-

Black Holes With Magnetic Charge And Quantized Mass, A. Yu. Ignatiev, G. C. Joshi, Kameshwar C. Wali

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We examine the issue of magnetic charge quantization in the presence of black holes. It is pointed out that quantization of magnetic charge can lead to the mass quantization for magnetically charged black holes. We also discuss some implications for the experimental searches of magnetically charged black holes.

Light-Heavy Symmetry: Geometric Mass Hierarchy For Three Families, Aharon Davidson, Tomer Schwartz, Kameshwar C. Wali

Physics - All Scholarship

The Universal Seesaw pattern coupled with a Light

↔ Heavy symmetry principle leads to the Diophantine equation N =NXi =1ni, where ni ≥ 0 and distinct. Its unique non-trivial solution (3 = 0+1+2) gives rise to the geometric mass hierarchy mW, mWǫ, mWǫ2 for N = 3 fermion families. This is realized in a model where the hybrid (yet Up ↔ Down symmetric) quark mass relations m dmt ≈ m2 c ↔ mumb ≈ m2 s play a crucial role in expressing the CKM mixings in terms of simple mass ratios, notably sin θC ≈ m c m b . …