A nonextensive approach to the dynamics of financial observables

We present results about financial market observables, specifically returns and traded volumes. They are obtained within the current nonextensive statistical mechanical framework based on the entropy $S_{q}=k\frac{1-\sum\limits_{i=1}^{W} p_{i} ^{q}}{1-q} (q\in \Re)$ ($S_{1} \equiv S_{BG}=-k\sum\limits_{i=1}^{W}p_{i} \ln p_{i}$). More precisely, we present stochastic dynamical mechanisms which mimic probability density functions empirically observed. These mechanisms provide possible interpretations for the emergence of the entropic indices $q$ in the time evolution of the corresponding observables. In addition to this, through multi-fractal analysis of return time series, we verify that the dual relation $q_{stat}+q_{sens}=2$ is numerically satisfied, $q_{stat}$ and $q_{sens}$ being associated to the probability density function and to the sensitivity to initial conditions respectively. This type of simple relation, whose understanding remains ellusive, has been empirically verified in various other systems.Comment: Invited paper to appear in special issue of Eur. Phys. J. B dedicated to econophysics, edited by T. Di Matteo and T. Aste. 7 page

Composite Charge 8/3 Resonances at the LHC

In composite Higgs models with partial compositeness, the small value of the observed Higgs mass implies the existence of light fermionic resonances, the top partners, whose quantum numbers are determined by the symmetry (and symmetry breaking) structure of the theory. Here we study light top partners with electric charge 8/3, which are predicted, for instance, in some of the most natural composite Higgs realizations. We recast data from two same sign lepton searches and from searches for microscopic blackholes into a bound on its mass, M8/3 > 940 GeV. Furthermore, we compare potential reach of these searches with a specifically designed search for three same-sign lepton, both at 8 and 14 TeV. We provide a simplified model, suitable for collider analysis.Comment: Minor comments are added to match published versio

Wigner Functions in High Energy Physics

Recent developments are (meta)reviewed in the applications of Wigner functions to describe the observed single particle spectra and two-particle Bose-Einstein (or Hanbury Brown -- Twiss) correlations in high energy particle and nuclear physics, with examples from hadron-proton and Pb + Pb collisions at CERN SPS.Comment: 4 pages, invited talk at the Wigner Centennial Conference, Pecs, Hungary, July 200

On the Phase of B0B^0--B0ˉ\bar {B^0} Mixing Matrix Elements in the SUSY Standard Model

It is shown that the complex phase of $B^0$--$\bar {B^0}$ mixing matrix element is same as that of the standard model one up to the minor correction of the order of $(m_c/m_t)^2$ or less in the SUSY standard model. This conclusion is valid as far as the Yukawa coupling constants are perturbative and realistic, and can be available for other realistic models where generation mixing and CP violation are solely due to Yukawa interaction among quarks and Higgs doublets.Comment: 8 pages, LaTeX file, figures appended in uuencoded gzipped EPS forma