The St{\o}rmer problem for an aligned rotator

The effective potential energy of the particles in the field of rotating uniformly magnetized celestial body is investigated. The axis of rotation coincides with the axis of the magnetic field. Electromagnetic field of the body is composed of a dipole magnetic and quadrupole electric fields. The geometry of the trapping regions is studied as a function of the magnetic field magnitude and the rotation speed of the body. Examples of the potential energy topology for different values of these parameters are given. The main difference from the classical St{\o}rmer problem is that the single toroidal trapping region predicted by St{\o}rmer is divided into equatorial and off-equatorial trapping regions. Applicability of the idealized model of a rotating uniformly magnetized sphere with a vacuum magnetosphere to real celestial bodies is discussed.Comment: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society Published by Oxford University Pres

Effective potential energy in St\ormer's problem for an inclined rotating magnetic dipole

We discuss the dynamics of a charged nonrelativistic particle in electromagnetic field of a rotating magnetized celestial body. The equations of motion of the particle are obtained and some particular solutions are found. Effective potential energy is defined on the base of the first constant of motion. Regions accessible and inaccessible for a charged particle motion are studied and depicted for different values of a constant of motion.Comment: Accepted for publication in Astrophysics and Space Scienc

Prospects for the measurement of B_s oscillations with the ATLAS detector at LHC

The prospects for the measurement of $B_{s}^{0}$ oscillations with the ATLAS detector at the Large Hadron Collider are presented. $B_{s}^{0}$ candidates in the $D_{s}^{-} \pi^{+}$ and $D_{s}^{-} a_{1}^{+}$ decay modes from semileptonic events were fully simulated and reconstructed, using a detailed detector description. The sensitivity and the expected accuracy for the measurement of the oscillation frequency were derived from unbinned maximum likelihood amplitude fits as functions of the integrated luminosity. A detailed treatment of the systematic uncertainties was performed. The dependence of the measurement sensitivity on various parameters was also evaluated.Comment: Invited talk at the Workshop on the CKM Unitarity Triangle, IPPP Durham, April 2003 (eConf C0304052). 4 pages LaTeX, 2 eps figure