Quark Lagrangian diagonalization versus non-diagonal kinetic terms

Loop corrections induce a dependence on the momentum squared of the coefficients of the Standard Model Lagrangian, making highly non-trivial (or even impossible) the diagonalization of its quadratic part. Fortunately, the introduction of appropriate counterterms solves this puzzle.Comment: 2 pages, 1 figur

Modification of Coulomb law and energy levels of hydrogen atom in superstrong magnetic field

The screening of a Coulomb potential by superstrong magnetic field is studied. Its influence on the spectrum of a hydrogen atom is determined.Comment: Lectures at 39 ITEP Winter School and 11 Baikal Summer School; 12 pages, 5 figure

Mixing angles of quarks and leptons in Quantum Field Theory

45 pages, 6 figuresInternational audienceArguments coming from Quantum Field Theory are supplemented with a 1-loop perturbative calculation to settle the non-unitarity of mixing matrices linking renormalized mass eigenstates to bare flavor states for non-degenerate coupled fermions. We simultaneously diagonalize the kinetic and mass terms and counterterms in the renormalized Lagrangian. SU(2)_L gauge invariance constrains the mixing matrix in charged currents of renormalized mass states, for example the Cabibbo matrix, to stay unitary. Leaving aside CP violation, we observe that the mixing angles exhibit, within experimental uncertainty, a very simple breaking pattern of SU(2)_f horizontal symmetry linked to the algebra of weak neutral currents, the origin of which presumably lies beyond the Standard Model. It concerns: on one hand, the three quark mixing angles; on the other hand, a neutrino-like pattern in which theta_{23} is maximal and tan(2 theta_{12})=2. The Cabibbo angle fulfills the condition tan (2 theta_c)=1/2 and theta_{12} for neutrinos satisfies accordingly the ``quark-lepton complementarity condition ''theta_c + theta_{12}= \pi/4. theta_{13} = +- 5.7 10^{-3} are the only values obtained for the third neutrino mixing angle that lie within present experimental bounds. Flavor symmetries, their breaking by a non-degenerate mass spectrum, and their entanglement with the gauge symmetry, are scrutinized; the special role of flavor rotations as a very mildly brokensymmetry of the Standard Model is outlined

The Standard Model of Leptons as a Purely Vectorial Theory

We propose a way to reconcile the Standard Model of leptons with a purely vectorial theory. The observed neutrino is predicted to be massless. The unobservability of its partner and the $V-A$ structure of the weak currents are given the same origin.Comment: 10 pages. Latex, 8 postscript figures included. We have corrected 2 (cancelling) sign misprints, and made explicit that we also recover the usual couplings of the U(1) gauge field B. The conclusions are unchanged. PAR-LPTHE 93/1

Binary systems of neutral mesons in Quantum Field Theory

Quasi-degenerate binary systems of neutral mesons of the kaon type are investigated in Quantum Field Theory (QFT). General constraints cast by analyticity and discrete symmetries P, C, CP, TCP on the propagator (and on its spectral function) are deduced. Its poles are the physical masses; this unambiguously defines the propagating eigenstates. It is diagonalized and its spectrum thoroughly investigated. The role of ``spurious'' states, of zero norm at the poles, is emphasized, in particular for unitarity and for the realization of TCP symmetry. The K_L-K_S mass splitting triggers a tiny difference between their CP violating parameters \epsilon_L and \epsilon_S, without any violation of TCP. A constant mass matrix like used in Quantum Mechanics (QM) can only be introduced in a linear approximation to the inverse propagator, which respects its analyticity and positivity properties; it is however unable to faithfully describe all features of neutral mesons as we determine them in QFT, nor to provide any sensible parameterization of eventual effects of TCP violation. The suitable way to diagonalize the propagator makes use of a bi-orthogonal basis; it is inequivalent to a bi-unitary transformation (unless the propagator is normal, which cannot occur here). Problems linked with the existence of different ``in'' and ``out'' eigenstates are smoothed out. We study phenomenological consequences of the differences between the QFT and QM treatments. The non-vanishing of semi-leptonic asymmetry \delta_S - \delta_L does not signal, unlike usually claimed, TCP violation, while A_TCP keeps vanishing when TCP is realized. We provide expressions invariant by the rephasing of K0 and K0bar.Comment: 44 pages, 2 figures. Version to appear in Int. J. Mod. Phys.

An Exploratory Study on Sustainable ICT Capability in the Travel and Tourism Industry: The Case of a Global Distribution System Provider

Climate change is one of the biggest challenges facing humanity today. Environmental values have spread globally and consumer beliefs are pressurizing firms in almost all industries to comply with green regulations. Sustainability has become such an important part of business strategy that almost every major company now has an executive with “sustainability” in their title. The travel and tourism industry produced 14 percent of global greenhouse gas emissions in 2010. Policy makers have responded with ambitious targets. The European Union aims to achieve a 60 percent reduction in transport sector emissions by 2050. This exploratory study draws on the sustainable ICT capability maturity framework (SICT-CMF) and the case of the Amadeus IT Group, a large travel and tourism industry corporate enterprise that specializes in IT solutions. The study investigates the current capability maturity level of sustainable ICT in the company. The findings suggest that the company is a market leader in terms of sustainability initiatives and that it demonstrates an “advanced” level of sustainability capability. We discuss the lessons learned from Amadeus’ experience

Critical nucleus charge in a superstrong magnetic field: effect of screening

A superstrong magnetic field stimulates the spontaneous production of positrons by naked nuclei by diminishing the value of the critical charge Z_{cr} . The phenomenon of screening of the Coulomb potential by a superstrong magnetic field which has been discovered recently acts in the opposite direction and prevents the nuclei with Z52 for a nucleus to become critical stronger B are needed than without taking screening into account.Comment: 13 pages, 2 figures, version to be published in Physical Review

Modification of Coulomb law and energy levels of the hydrogen atom in a superstrong magnetic field

We obtain the following analytical formula which describes the dependence of the electric potential of a point-like charge on the distance away from it in the direction of an external magnetic field B: \Phi(z) = e/|z| [ 1- exp(-\sqrt{6m_e^2}|z|) + exp(-\sqrt{(2/\pi) e^3 B + 6m_e^2} |z|) ]. The deviation from Coulomb's law becomes essential for B > 3\pi B_{cr}/\alpha = 3 \pi m_e^2/e^3 \approx 6 10^{16} G. In such superstrong fields, electrons are ultra-relativistic except those which occupy the lowest Landau level (LLL) and which have the energy epsilon_0^2 = m_e^2 + p_z^2. The energy spectrum on which LLL splits in the presence of the atomic nucleus is found analytically. For B > 3 \pi B_{cr}/\alpha, it substantially differs from the one obtained without accounting for the modification of the atomic potential.Comment: version to be published in Physical Review D (incorrect "Keywords" in previous version have been cancelled

Next-to-MLLA corrections to single inclusive kt-distributions and 2-particle correlations in a jet

The hadronic kt-spectrum inside a high energy jet is determined including corrections of relative magnitude O{\sqrt{\alpha_s}} with respect to the Modified Leading Logarithmic Approximation (MLLA), in the limiting spectrum approximation (assuming an infrared cut-off Q0 =Lambda_{QCD}) and beyond Q_0\ne\Lambda_{QCD}. The results in the limiting spectrum approximation are found to be, after normalization, in impressive agreement with preliminary measurements by the CDF collaboration, unlike what occurs at MLLA, pointing out small overall non-perturbative contributions. Within the same framework, 2-particle correlations inside a jet are also predicted at NMLLA and compared to previous MLLA calculations.Comment: 35 pages and 39 figures. Comments, appendices, figures, references added. Version to appear in Phys. Rev.

An improved dynamic graph tracking algorithm

We propose several improvements of an existing baseline short-term visual tracking algorithm. The baseline tracker applies a dynamic graph representation to track the target. The target local parts are used as nodes in the graph, while the connections between neighboring parts represent the graph edges. This flexible model %representation of the target structure proves useful in the presence of extensive target visual changes throughout the sequence. A recent benchmark has shown that the tracker compares favorably in performance with other state-of-the-art trackers, with a notable weakness in cases of input sequences with high variance in scene and object lighting. We have performed an in-depth analysis of the tracker and propose a list of improvements. With respect to an unstable component in the tracker implementation of the foreground/background image segmentation, we propose an improvement which boosts the accuracy in cases of rapid illumination change of the target. We also propose a dynamic adjustment of the aforementioned segmentation with respect to the size of the resulting foreground, which improves tracking reliability and reduces the number of tracking failures. The implemented improvements are analyzed on the VOT2015 benchmark. Fixing the unstable component yields improvements in cases of rapid illumination change and reduces failure rate, while the dynamic segmentation adjustment improves tracking accuracy and robustness in the vast majority of cases, barring rapid illumination change