December 19th, 2019

лошадь, диаграмма, Фейнман

Лекции по частицам одного и того же автора

Flavor physics and CP violation:

(Submitted on 17 Dec 2019)
Lectures at the 53rd Winter School of Petersburg Nuclear Physics Institute and European School on High Energy Physics ESHEP2019, Saint-Petersburg, Russia.
Comments: 37 pages, submitted for publication in a CERN Yellow Report (YR). arXiv admin note: substantial text overlap with arXiv:hep-ph/0307218

CKM matrix and CP violation in B-mesons:

M.Vysotsky (ITEP, Moscow)
(Submitted on 17 Jul 2003 (v1), last revised 25 Sep 2003 (this version, v2))
Planned as a review of CPV in B-mesons which covered recent B-factories results these lectures appeared to be a bit wider. It is not natural to be limited by direct CPV and that in mixing in B-mesons and not to speak about the analogous phenomena in K-mesons since it is very useful and interesting to study what is common and what is different in these systems and why. CKM matrix elements are extracted from K and B mixings and decays and the deviation from unitarity of CKM matrix may become a place in which New Physics will show up. So we discuss this simple and elegant piece of Standard Model as well.
Comments: 51 pages, 10 figures, to be published in the Proceedings of the XXXI ITEP Winter School, Moscow, Russia, 18-26 February 2003
лошадь, диаграмма, Фейнман

О поверхностных плазмонах

Formation of normal surface plasmon modes in small sodium nanoparticles:

Formation of surface plasmon modes in sodium nanoclusters containing 20-300 atoms was studied using the GW method. It is shown that in the small Na nanoparticles up to 2 nm in size, the loss function Im[ϵ−1] is dominated by a single peak corresponding to localized surface plasmon resonance (LSPR). For particles of 2 nm and more, a resonance corresponding to surface plasmon polariton (SPP) oscillations begins to form, as well as a resonance corresponding to volume plasmon (VP) excitations. Considering the above, the linear size of a particle in the range of 0.7-3.7 nm can be estimated as the lower limit for metal nanodevices operating with SPP. On the example of spherical nanoparticles consisting of a silicon core coated with sodium atoms, it is shown that the LSPR mode is selectively suppressed while the SPP mode is not. Such composite structures can be considered as an example of nanoplasmonic devices with selectively tuned characteristics.
Comments: 13 pages, 4 figures
лошадь, диаграмма, Фейнман

О конструкции градиентных катушек для МРТ

Gradient Coil Design and Realization for a Halbach-Based MRI System:

In this paper we design and construct gradient coils for a Halbach permanent magnet array magnetic resonance (MR) scanner. The target field method, which is widely applied for the case of axial static magnetic fields, has been developed for a transverse static magnetic field as produced by a Halbach permanent magnet array. Using this method, current densities for three gradient directions are obtained and subsequently verified using a commercial magneto-static solver. Stream functions are used to turn the surface current densities into wire patterns for constructing the gradient coils. The measured fields are in good agreement with simulations and their prescribed target fields. Three dimensional images have been acquired using the constructed gradient coils with very low degree of geometric distortion.