Thesis topics in Physics (for October 2022, round 2)

Application deadline: August 26th.

  1. Prediction of the cross-sections for the synthesis of super heavy nuclei
    • Supervisor: dr hab. Michał Kowal, prof. NCBJ
    • Description: The Ph.D. thesis will aim to assess the possibility of producing superheavy nuclei in future experiments and understanding the mechanisms governing the synthesis reactions. Particular emphasis will be placed on understanding and analyzing the hindrance phenomenon in the fusion process. For this purpose, we will use a dissipative dynamic based on stochastic equations. We will apply the diffusion equations on multidimensional energy surfaces with total angular momentum taken into account. Additionally, we will examine the quantum shell effect on the probability of formation and survival of a newly created superheavy nucleus.
    • Funding: NCBJ Fellowship
  2. Quantum groups from quantum gravity
    • Supervisor: prof. dr hab. Jerzy Kowalski-Glikman
    • Description: The quest for quantum gravity is one of the most important unfinished challenges of modern high energy theoretical physics. Its solution will presumably provide us, among others, with an understanding of very early stages of the evolution of the universe and physics of black holes. Unfortunately, in the construction of this theory we not only encounter enormous technical problems, but also, we seem to be guided by only few experimental hints. This is due to the fact that the energy scale where quantum gravity effects become dominant is about 15 orders of magnitude higher that the highest energies seen at LHC. It is of major importance therefore to investigate possible traces that quantum gravity generically leaves at lower energies, changing slightly the theories that we know well and for which we can try to experimentally observe minute departures from the expected behavior. For example, the influence of quantum gravity may modify the early universe cosmological scenarios and the theory of quantum fields, used in the construction of the Standard Model of elementary particle physics. One of the possible ways to organize these possible quantum gravity corrections is to take as a starting point the hypothesis that they are captured by a subtle modification of our low energy theories associated with the emergence of quantum groups that become necessary to properly describe the spacetime symmetries. The aim of the research project the PhD student is supposed to undertake would be to to find out how quantum groups emerge as an effective description of symmetries of fields and particles when quantum gravity effects are considered. Literature: J.Kowalski-Glikman, “A short introduction to kappa-deformation”, Int. J. Mod. Phys. A 32 (2017) no.35, 1730026, doi:10.1142/S0217751X17300265 [arXiv:1711.00665 [hep-th]].
    • Funding: NCBJ Fellowship
  3. Characterizing the evolutionary pathways of the most compact, quiescent galaxies
    • Supervisor: Prof. dr hab. Agnieszka Pollo
    • Auxiliary Supervisor: Dr Darko Donevski
    • Description: The formation of massive quiescent galaxies represents one of the critical phases in the evolution of cosmic structures. Observations of the high-redshift Universe revealed that the quenching systems already existed at early epoch (z~3-4), although with striking structural differences (e.g., much smaller physical sizes) with respect to passive elliptical galaxies in the local Universe. To understand the most massive objects in the Universe we have to study and analyse the population of ultra-compact, quiescent galaxies. These so-called “red nuggets” are believed to be quenched at high-redshifts (𝑧∼2-3) but their later phases of evolution are still unclear. While most “red nuggets” merged with other galaxies over billions of years, some of them managed to pass through the long cosmic history unchanged, offering a unique laboratory for testing the scenarios of massive galaxy evolution.While significant observational and theoretical efforts are being directed toward improving our understanding of the evolutionary pathways of ultra-compact, massive galaxies, many important questions remain open: How did ultra-compact quiescent galaxies form? Are they a unique population or mixture of sources with different origins? How do their physical properties change over cosmic time? How do large-scale environments affect their evolution? The aim of this doctoral project is to address questions about the nature and physicial properties of red nuggets and their relicts which can be found in our local Universe. To do so, one has to unveil the nature of the general population of compact quiescent galaxies. The successful candidate will study the topic by analyzing a unique statistical set of observational data and the state-of-the-art simulations. The project intends to provide the solid ground needed for interpreting future unprecedented data sets of galaxies and their environments observed with ground-based facilities (i.e., Rubin observatory) and space telescopes (i.e., JWST, Euclid).
    • Funding: NCBJ Fellowship
  4. Vector boson physics with the CMS experiment at the Large Hadron Collider
    • Supervisor: Dr hab. Michał Szleper, prof. NCBJ
    • Description: Vector Boson Scattering (VBS) is a wide class of processes of paramount importance for the proper understanding of the mechanism of electroweak symmetry breaking. They probe Higgs couplings as well as triple and quartic gauge couplings, and thus are indirect checks for physics beyond the Standard Model. We look for two strong candidates who would like to work with the CMS experiment at CERN as part of their Ph.D. program. The successful candidates are expected to participate in the analysis of VBS processes based on data that will be collected during Run 3 of the LHC. The main focus of the analysis will be search for new physics in the same-sign WW scattering process and the WZ scattering process using the model independent framework of Effective Field Theories. Prerequisits are a M.Sc. degree in particle physics or a closely related field, good computing skills and ability to establish a friendly collaboration with the international scientific community at CERN. Good understanding of particle physics theory will be a bonus. The successful candidates are also expected to participate in activities related to the maintenance and operation of the Overlap Muon Track Finder (OMTF) system of the CMS detector, as part of their service work within the Warsaw CMS group.
    • Funding: NCN Fellowship
  5. Determination of the hadronic vacuum polarization contribution to the muon anomalous magnetic moment
    • Supervisor: Prof. dr hab. Wojciech Wiślicki
    • Co-supervisor: Prof. dr hab. Andrzej Kupść
    • Description: The muon anomalous magnetic moment g-2, where g is the gyromagnetic ratio of the muon, is one of the exceptional cases in particle physics at low energy where a significant discrepancy between measurement and Standard Model (SM) prediction has persisted for more than 20 years. This discrepancy, now reaching 4.2 sigma, could be a compelling evidence of physics beyond the SM. In view of the new experimental efforts under way at Fermilab (USA) and J-PARC (Japan) to improve the g-2 accuracy, a confirmation of its SM prediction is now mandatory. Its hadronic contributions are under particular scrutiny, as they induce the main uncertainty of the SM prediction. The KLOE experiment at the phi-factory DAphNE in Frascati (near Rome) is the first to have employed Initial State Radiation to precisely determine the e+e- –> pi+pi-gamma cross section below 1 GeV. This PhD project is focused on the analysis of the full KLOE data sample and should improve by a factor 2 current accuracy on contribution to g-2 from hadronic vacuum polarization. It will place a significant constraint on the SM prediction to the muon g-2. The project also requires involvement in development of Monte Carlo generator for this process. A successful candidate is expected to work on the analysis of data and simulation software and will be assisted by experienced senior colleagues.
    • Funding: NCBJ Fellowship