A generalization of the Ginzburg-Landau theory to p-wave superconductors

We succeed to build up a straightforward theoretical model for spin-triplet p-wave superconductors by introducing in Ginzburg-Landau theory a second order parameter and a suitable interaction between the two mean fields.Comment: RevTeX, 4 pages, no figure

Total thyroidectomy associated to chemotherapy in primary squamous cell carcinoma of the thyroid

Primary squamous cell carcinoma of the thyroid (PSCCT) is a rare malignant disease with rapid fatal prognosis. The onset is generally characterized by sudden bilateral latero-cervical lymphadenopathy. The Authors report patient of 58-year-old who referred for evaluation of rapidly aggravating bilateral latero-cervical lymphadenopathy. The US highlighted the presence of a hypoechoic nodular lesion characterized by peri and intra-nodular vascularization. Multilayer CT showed diffused involvement of mediastinal and bilateral latero-cervical lymph nodes, with no evidence of primary pulmonary neoplasia or elsewhere. The patient underwent total thyroidectomy. The peri-isthmic tissue was removed due to the presence of a small roundish formation, that was due to lymph node metastasis at histological examination. Histological diagnosis: PSCCT. The immunohistochemical panel of the thyroid lesion was indispensable for the differential diagnosis between PSCCT, medullary carcinoma, anaplastic carcinoma, and thyroid metastasis of neoplasia with unknown primitiveness. The patient underwent chemotherapeutic treatment with Carboplatin and Paclitaxel with modest improvement of dysphagia symptoms and reduction of 10-15% of the target lesions. The clinical course was characterized by loco-regional progression of the disease with exitus in 10 months after diagnosis. Survival and quality of life after surgical therapy and chemotherapy were like that of patients undergoing only chemotherapy. Due to the extreme rarity of the neoplasia, 60 cases described in Literature, no exclusive guidelines are reported for PSCCT. More extensive case studies are needed to evaluate the effects of total thyroidectomy with intent R0/R1 on improving survival and quality of life of patients with PSCCT

Slower-than-Light Spin-1/2 Particles Endowed with Negative Mass Squared

Extending in a straightforward way the standard Dirac theory, we study a quantum mechanical wave-equation describing free spinning particles --which we propose to call "Pseudotachyons" (PT's)-- which behave like tachyons in the momentum space, but like subluminal particles (v<c) in the ordinary space. This is allowed since, as it happens in every quantum theory for spin-1/2 particles, the momentum operator (that is conserved) and the velocity operator (that is not) are independent operators, which refer to independent quantities. As a consequence, at variance with ordinary Dirac particles, for PT's the average velocity is not equal to the classical velocity, but actually to the velocity "dual" of the classical velocity. The speed of PT's is therefore smaller than the speed of light. Since a lot of experimental data seems to involve a negative mass squared for neutrinos, we suggest that these particles might be PT's, travelling, because of their very small mass, at subluminal speeds very close to c. The present theory is shown to be separately invariant under the C, P, T transformations; the covariance under Lorentz transformations is also proved. Furthermore, we derive the kinematical constraints linking 4-impulse, 4-velocity and 4-polarization of free PT'sComment: LaTeX; 20 page

CPT-violating neutrino oscillations

We propose a simple phenomenological model predicting, through Lorentz symmetry breaking, a CPT-violating asymmetry between particle and antiparticle states in neutrino oscillations involving sterile neutrinos. Such a model is able to explain the apparently observed anomalous excess of low-energy \nu_e-like events, reported by the MiniBooNE collaboration, as well as the non-observation of the corresponding anomalous excess of \ov{\nu}_e-like events. The present model leads to very specific physical predictions in the neutrino oscillations scenario, and account for the observed anomalies in terms of only one CPT-Lorentz violation parameter of the order of the Grand-Unification energy scale.Comment: revtex, 4 pages, no figure

Zitterbewegung, chirality, and minimal conductivity in graphene

It has been recently demonstrated experimentally that graphene, or single-layer carbon, is a gapless semiconductor with massless Dirac energy spectrum. A finite conductivity per channel of order of $e^{2}/h$ in the limit of zero temperature and zero charge carrier density is one of the striking features of this system. Here we analyze this peculiarity based on the Kubo and Landauer formulas. The appearance of a finite conductivity without scattering is shown to be a characteristic property of Dirac chiral fermions in two dimensions.Comment: final version; 4 pages, 1 eps figur

Non-Newtonian Mechanics

The classical motion of spinning particles can be described without employing Grassmann variables or Clifford algebras, but simply by generalizing the usual spinless theory. We only assume the invariance with respect to the Poincare' group; and only requiring the conservation of the linear and angular momenta we derive the zitterbewegung: namely the decomposition of the 4-velocity in the newtonian constant term p/m and in a non-newtonian time-oscillating spacelike term. Consequently, free classical particles do not obey, in general, the Principle of Inertia. Superluminal motions are also allowed, without violating Special Relativity, provided that the energy-momentum moves along the worldline of the center-of-mass. Moreover, a non-linear, non-constant relation holds between the time durations measured in different reference frames. Newtonian Mechanics is re-obtained as a particular case of the present theory: namely for spinless systems with no zitterbewegung. Introducing a Lagrangian containing also derivatives of the 4-velocity we get a new equation of the motion, actually a generalization of the Newton Law a=F/m. Requiring the rotational symmetry and the reparametrization invariance we derive the classical spin vector and the conserved scalar Hamiltonian, respectively. We derive also the classical Dirac spin and analyze the general solution of the Eulero-Lagrange equation for Dirac particles. The interesting case of spinning systems with zero intrinsic angular momentum is also studied.Comment: LaTeX; 27 page

An Analysis of Musculoskeletal Variables, Comparative to Team Norms, Leading to an ACL Rupture

Please refer to the pdf version of the abstract located adjacent to the title

Dependence of the critical temperature on the Higgs field reparametrization

We show that, despite of the reparametrization symmetry of the Lagrangian describing the interaction between a scalar field and gauge vector bosons, the dynamics of the Higgs mechanism is really affected by the representation gauge chosen for the Higgs field. Actually, we find that, varying the parametrization for the two degrees of freedom of the complex scalar field, we obtain different expressions for the Higgs mass: in its turn this entails different expressions for the critical temperatures, ranging from zero to a maximum value, as well as different expressions for other basic thermodynamical quantities.Comment: revtex, 12 pages, 2 eps figure

Zitterbewegung in External Magnetic Field: Classic versus Quantum Approach

We investigate variations of the Zitterbewegung frequency of electron due to an external static and uniform magnetic field employing the expectation value quantum approach, and compare our results with the classical model of spinning particles. We demonstrate that these two so far compatible approaches are not in agreement in the presence of an external uniform static magnetic field, in which the classical approach breaks the usual symmetry of free particles and antiparticles states, i.e. it leads to CP violation. Hence, regarding the Zitterbewegung frequency of electron, the classical approach in the presence of an external magnetic field is unlikely to correctly describe the spin of electron, while the quantum approach does, as expected. We also show that the results obtained via the expectation value are in close agreement with the quantum approach of the Heisenberg picture derived in the literature. However, the method we use is capable of being compared with the classical approach regarding the spin aspects. The classical interpretation of spin produced by the altered Zitterbewegung frequency, in the presence of an external magnetic field, are discussed.Comment: 16 pages, no figure