Mgr. Oldřich Kepka, Ph.D.

My research is focused on the ATLAS experiment at CERN. I am actively contributing to measurements studying effects of strong interactions between quarks and gluons and testing fundamental properties of the electroweak theory in multiboson processes.
I am currently a convener of the Standard Model Group in ATLAS and oversee analysis design and paper publications from this group.
In terms of physics expertise, it spans a broad range of themes, signatures and final states appearing in events produced in high-energetic proton-proton collisions. They can briefly be summarized:
• multiboson production, including vector boson scattering and boson polarization measurements, as well as search for beyond the standard model physics using EFT approach
• measurements with a single W or Z boson in the final state, covering precision measurement of fundamental parameters of the Standard model such as W or Z mass, weak mixing angle and lepton flavor universality in weak boson decays
• measurements including particle jets, photons, studies of strong interaction and proton structure at smallest accessible distances
• studies of non-perturbative regime of strong interactions, which also include dedicated forward detecting capabilities to register forward-going protons, neutrons, and photons.
I am actively working on the exploration of special type of pp events induced by the exchange of two photons in the initial state.
During PhD, I pioneered the feasibility of measuring the photon-induced production to study triple and quartic interactions between EW bosons with the use of forward proton- tagging devices.
More recently, I have been leading explorations of these interactions which resulted in the observation of photon induced production of the pair of W bosons by ATLAS. The observation extensively built upon my previous experience with measuring the charged-particle distributions using the ATLAS inner tracker.
I performed several measurements of charged-particle distributions in pp collisions at various LHC energies. They provided essential inputs to improve MC simulation of soft hadronic activity which needs to be retuned for every new collision energy reached by the LHC. Diffractive production is another domain of my expertise.
Our team from the institute of Physics performed the first diffractive measurement using rapidity gap method. These large regions in rapidity devoid of energy were defined based on detailed studies of particle deposition in the ATLAS calorimetry. The gap reconstruction method was later also carried over to heavy ion collisions to improve rejections of EM induced ultra-peripheral collisions that correspond to large reducible background in some HI measurements.
In 2017, I moved to CERN to broaden my professional scope. I became involved in all aspects of the ATLAS online Pixel detector operation. This work included installation of various upgrades of the detector readout and active SW development of Pixel specific data acquisition software as well as plugins connected to the ATLAS’ general TDAQ infrastructure. My activity extended to detector operation, calibration, and online monitoring. I held various responsibilities in Pixel, such as the Pixel DAQ coordinator and Pixel Run coordinator.

I work at the Institute of Physics of the Czech Academy of Sciences.