Date and Time: Tuesday, 12 September 2017, at 11:00 AM

Venue: room 310, Laboratory of Information Technologies

Seminar topic: «Proton spin puzzle and confinement of quarks»

Speaker: B.F. Kostenko

Abstract:

By means of the Dirac equation written in the cylindrical coordinates, an influence of confinement in the gluon Y-string region on quark helicities in a high-speed nucleon is investigated. The system of computer mathematics MAPLE recommends the Runge-Kutta-Fehlberg algorithm for numerical so- lution of an initial value problem stated. However, it was established that a solution found on this route is inconsistent with confinement conditions, and that the formulated Cauchy problem has nonunique solution. A cause of this ambiguity is made clear, as well as an algorithm and a solution concordant with confinement are searched out in this study. Calculations have shown that the confinement effect is able to induce strongly the quark spin flip in the gluon Y-string region. Thus, a missing part of proton spin measured in experiments on deep inelastic scattering of leptons may be hidden in the orbital angular momentum of quarks.