Dr. Aleksandrs Aleksejevs, B.Sc., M.Sc. (Latvia), Ph.D. (Manitoba)
Main research topics:
Precision Tests of the Standard Model
Who would not want to know the basic constituents of our world and the way they interact? Nuclear and particle physics studies exactly that. According to the Standard Model of particle physics, there are six types of quarks, six types of leptons, and corresponding anti-particles connected by four fundamental interactions. However, the recent evidence coming from neutrino oscillation, dark matter and dark energy, and quantum gravity showed that the 40-year old Standard Model may be incomplete, and that we may be at the threshold of a new theory and "New Physics". One way to look for possible signals of new physics is with high-precision experiments at lower energy, which can provide indirect access to physics at multi-TeV scales and play an important complementary role to the Large Hadron Collider research program. This research requires both experimental and theoretical effort, and the new-generation experiments will need a new degree of precision from theory.
My colleagues and I strive to bring subatomic physics computations to the next level and to provide the most precise and reliable theoretical input for the high-precision experiments by taking advantage of the new semi-automated symbolic computing methods. Our innovative computational models can be used for a wide range of applications, including next-to-leading and next-to-next-to-leading electroweak radiative corrections for Møller scattering, electron-proton and positron-proton scattering, modeling pion electroproduction and many others. This research program can be a crucial contribution to cutting-edge Canadian science in the coming decade, and it would also allow for training a new generation of researchers who would enable Canada to maintain its position at the forefront of world-class research for years to come.
Properties of Hadrons in the Effective Field Theories
The electromagnetic polarizabilities of a particle with a structure characterize the dipole moments induced by the presence of an external electromagnetic field. They therefore constitute fundamental quantities, which represent a measure of the rigidity, stiffness or resistance to deformation of the internal structure of the composite system upon imposition of an external electromagnetic field. One of the ways to study response of the baryons and mesons to an external electromagnetic field is through a Compton scattering. This allows us to extract fundamental response structure functions such as electric and magnetic polarizabilities, and thus obtain information about the baryons and mesons internal degrees of freedom. Values of these polarizabilities are key to understanding of the internal dynamics of baryons and mesons in the external electromagnetic field. For instance just a sign of magnetic polarizability will define whether mesons have paramagnetic or diamagnetic structure. In this project we propose to perform a detailed study of the polarizabilities of all-lowest in mass baryons and mesons using our Computations Hadronic Model. This model was developed on the basis of Chiral Perturbation Theory.
Baryon structure in low energy QCD
Dynamical Polarizabilities of Baryons
High-energy hadron collisions
Parity violating tests of the Standard Model
Physics beyond the Standard Model and Dark Matter searches
Automatic Symbolic Calculations in Subatomic Physics
Radiative corrections and loop integrals
Research Funding Agency:
Students who are interested in MSc and PhD studies in particle and nuclear physics, please apply using following links:
MSc program: https://www.mun.ca/become/graduate/programs/physics.php
PhD program: http://www.mun.ca/become/graduate/programs/theoretical_physics.php