Welcome
to the theory and phenomenology of the physics of heavy-ion collisions group at the Department of Physics, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague.
Our group is located in the building of FNSPE at the adress: Brehova 7, Prague 1, 119 15, Czech Republic.
Our research interest
In the theory of hadron-hadron, hadron-nuclear and nucleus-nuclear collisions we compute the probability of new particle production and their properties.
We also investigate the passage of particles through the nuclear medium and its effects.
In nucleus-nuclear collisions we try to create the state of matter during the so-called Big-Bang, where the development of so-called quark-gluon plasma is predicted. In this context we study the reaction of matter immediately after the collision of two nuclei. At this point a number of effects and phenomena develops, which need to be theoretically correctly described.
Projects
Vector mesons wave functions and electroproduction cross sections
J.Cepila, J.Nemchik, M. Krelina and R.Pasechnik; Theoretical uncertainties in exclusive electroproduction of S-wave heavy quarkonia,
Eur.Phys.J. C79 (2019) no.6, 495 ;
arXiv:1901.0266
J.Cepila, J.Nemchik, M. Krelina and R.Pasechnik; Spin rotation effects in diffractive electroproduction of heavy quarkonia,
Eur.Phys.J. C79 (2019) no.2, 154 ;
arXiv:1812.03001
→ Datagrids and plot generator
Energy-dependent hot-spot model
→ Tables in text format with the predictions shown in the figures
In this work we introduce a model for the calculation of the DIS and vector meson production based on introducing hot spots inside the proton target. The hot spot has a Gaussian distribution arbitrariy placed inside a radius of the proton. The number of hot spots grows with energy or with decreasing Bjorken x. This model is build within the color dipole model using GBW parametrization for the dipole cross section.
J. Cepila, J. G. Contreras, J. D. Tapia Takaki, Energy dependence of dissociative J/ψ photoproduction as a signature of gluon saturation at the LHC,
Phys.Lett. B766 (2017) 186-191;
arXiv:1608.07559
b-dependent solution of the Balitsky-Kovchegov equation
In this work we solved the impact-parameter dependent Balitsky-Kovchegov equation with the recently proposed collinearly improved kernel. We find that the solutions do not present the Coulomb tails that have affected previous studies. We also show that once choosing an adequate initial condition it is possible to obtain a reasonable description of HERA data on the structure function of the proton, as well as on the cross section for the exclusive production of a J/ψ vector meson off proton targets. Here you can find the data sets associated with this work.
J. Cepila, J. G. Contreras, M. Matas; Collinearly improved kernel suppresses Coulomb tails in the impact-parameter dependent Balitsky-Kovchegov evolution, Phys.Rev. D99 (2019) no.5, 051502; arXiv:1812.02548
Nuclear structure function using b-dependent solution of the Balitsky-Kovchegov equation
In this work we have used the solution of the impact-parameter dependent Balitsky-Kovchegov equation with the collinearly improved kernel to predict nuclear structure function. We have proposed two models. First model is a Glauber-Gribov approach with a scattering amplitude from the solution of the BK equation as an imput. The second is the solution of b-dependent BK equation with initial conditions resembling nuclear target. Here you can find the data sets associated with this work.
J. Cepila, J. G. Contreras, M. Matas; Predictions for nuclear structure functions from the impact-parameter dependent Balitsky-Kovchegov equation, arXiv:2002.11056