Latest documents http://publikationen.ub.uni-frankfurt.de/index/index/ Wed, 20 Feb 2008 16:25:34 +0100 Wed, 20 Feb 2008 16:25:34 +0100 http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/240 This work is dedicated to obtaining of analog of Bogoliubov's chain for the case of complex scalar field in QFT and renormalization problem of obtained equations is discussed. Konstantin Lyakhov preprint http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/240 Wed, 20 Feb 2008 16:25:34 +0100 http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/239 This article generalizes Schwinger’s mechanism for particles production in the arbitrary finite field volume. McLerran-Venugopolan(MV) model and iterative solution of DGLAP equation in the double leading log approximation for small x gluon distribution function were used to derive the new formula for initial chromofield energy density. This initial chromofield energy is distributed among color neutral clusters or strings of different length. This strings are stretched by receding nucleus. From the proposed mechanism of string fragmentation or color field decay based on exact solution of Dirac equation in the different finite volume, the new formulae for esimated baryon kinetic energy loss and rapidity spectrum of produced partons were derived. Konstantin Lyakhov preprint http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/239 Wed, 20 Feb 2008 16:18:24 +0100 http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/246 Strong chromofields developed at early stages of relativistic heavy-ion collisions give rise to the collective deceleration of net baryons from colliding nuclei. We have solved classical equations of motion for baryonic slabs under the action of time-dependent chromofield. We have studied sensitivity of the slab trajectories and their final rapidities to the initial strength and decay pattern of the chromofield as well as to the back reaction of produced plasma. This mechanism can naturally explain significant baryon stopping observed at RHIC, an average rapidity loss hδyi ≈ 2. Using a Bjorken hydrodynamical model with particle producing source we also study the evolution of partonic plasma produced as the result of chromofield decay. Due to the delayed formation and expansion of plasma its maximum energy density is much lower than the initial energy density of the chromofield. It is shown that the net-baryon and produced parton distributions are strongly correlated in the rapidity space. The shape of net-baryon spectra in midrapidity region found in the BRAHMS experiment cannot be reproduced by only one value of chromofield energy density parameter ǫ0, even if one takes into account novel mechanisms as fluctuations of color charges generated on the slab surface, and weak interaction of baryon-rich matter with produced plasma. The further step to improve our results is to take into account rapidity dependence of saturation momentum as explained in thesis. Different values of parameter ǫ0 has been tried for different variants of chromofield decay to fit BRAHMS data for net-baryon rapidity distribution. In accordance with our analysis, data for fragmentation region correspond to the lower chromofield energy densities than mid-rapidity region. χ2 analysis favors power-law of chromofield decay with corresponding initial chromofield energy density of order ǫf = 30GeV/fm3. Konstantin Lyakhov doctoralthesis http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/246 Wed, 20 Feb 2008 09:12:44 +0100