Projects / Programmes
Theoretical physics of nuclei, particles and fields
January 1, 2015
- December 31, 2018
| Code |
Science |
Field |
Subfield |
| 1.02.00 |
Natural sciences and mathematics |
Physics |
|
| 1.07.00 |
Natural sciences and mathematics |
Computer intensive methods and applications |
|
| Code |
Science |
Field |
| P002 |
Natural sciences and mathematics |
Physics |
| Code |
Science |
Field |
| 1.03 |
Natural Sciences |
Physical sciences |
Higgs boson, top quark LHC, flavor physics, CP violation, Physics beyond the Standard
Model, leptoquarks, CP asymmetry, the electric dipole moment, neutrino masses, grand unified theories, supersymmetry, AdS/CFT correspondence, lattice QCD, tetraquarks
Researchers (25)
Organisations (2)
Abstract
We shall investigate the dynamics of the nucleon resonances in the energy range where the strange mesons and baryons are expected to play an important role. Using the multichannel K-matrix formalism we shall study meson scattering and electro-production.
We will investigate whether the recently observed exotic tetraquark states such as Zc+ emerge from the first-principle lattice QCD. Systematic exploration of relevant channels will be performed to predict where other exotic and conventional hadrons may be experimentally expected in the future. We will also investigate QCD-like theories that may be responsible for the electroweak symmetry breaking, and perform the lattice calculation of the masses and widths for the resonances that can be searched experimentally.
We will study in detail the interactions of the Higgs boson with known and hypothetical new matter particles. Particular emphasis will be laid on the connections between Higgs boson physics and other fields, e.g., flavor violation, nuclear and leptonic electric dipole moments, top quark processes and other collider phenomenology, as well as dark matter searches in the universe and on earth.
We will study the role of scalar and vector leptoquarks in low and high energy processes, and systematically constrain relevant scenarios using the data from low-energy experiments and from LHC.
We intend to explore the impact of new physics on the role of electric dipole moment of the neutron and establish a connection with the observed asymmetry in the decays of mesons at low energies.
The origin of neutrino mass remains one of the unsolved mysteries in particle physics. This mechansim in its generalized form is now being probed at high and low energies, as well as using cosmological data. Due to the fundamental nature of this problem, there are numerous experiments in progress, that we expect will improve our insight in the origin of neutrino mass. This requires a detailed understanding of theories of neutrino mass and associated phenomena.
We will consider supersymmetric or nonsupersymmetric unified theories with well studied groups SU(5) and SO(10) and newer and less known as E6. Special care will be given presumably to proton decay and fermion masses and mixing angles. We will study the influence of R-parity breaking on the fermion mass relations.
We will develop the QLM, a variant of quasilinearization, and its applications to singular problems in quantum mechanics. We will develop the CFHHM, a method to calculate locally correct wave functions in the atomic three-body problem, mostly to get precise matrix elements in light ion ionization processes, e.g. the quasifree (QF) mechanism.
Significance for science
It is definitely important for the science in general to establish whether hadrons that are not conventional mesons qq or baryons qqq exist. In 2013 experiments have established first independently confirmed candidates of this sort - the so-called Zc+. Our aim is to establish whether such unconventional hadrons emerge from an ab-initio simulation of the underlying Quantum Chromodynamics. This task is urged by the theoretical as well as the experimental community. The systematic exploration and predictions for other relevant channels is also crucial for further searches and understanding the nature of exotic hadrons.
First principle lattice simulations of QCD have immensely advanced in the recent years due to the rapid rise of the super-computer power, but also due to the new theoretical ideas and algorithms. Until about 2011 all hadronic resonances were simulated as if they did not decay strongly, and the effects of thresholds were neglected. During 2012-2014 we were involved in the simulations that took these two important effects into account for the first time. Our future results with increased theoretical precision are urged for quantitative comparison with experiment. The next challenge would be the first-principle treatment of inelastic channels and the matrix elements between resonances, so the scientific community would definitely benefit from the first steps along these lines.
Certain interesting QCD-like theories of spontaneous symmetry breaking do not have many adjustable parameters, therefore the prediction of resonance masses and their decay widths in such theories will refute or confirm the theory when the relevant energy region is explored experimentally. This is clearly relevant for scientific knowledge in general.
The new results from the LHC, the super flavour factory (BelleII), space based experiments relevant for particle physics in the early universe (Planck, FERMI-LAT, AMS02) as well as several smaller experiments of particle and astroparticle physics will in the coming decade most probably fundamentally deepen our understanding of the basic laws of physics and their application to the early universe. Therefore, the proposed research program, combining in a novel way the measurements of these, has a high potential impact. Finally, it shall possibly open new avenues of experimental measurements both at the LHC as well as in low energy precision and astroparticle experiments.
In fundamental particle physics we are faced with many alternative extensions of the Standard model, however each of them is merely a hypothesis. In order to systematically narrow down possible hypotheses it crucial that we devise for each hypothesis an experiment that will be able to falsify it. The model with leptoquarks we will studied is, in this context, one of the sensible hypotheses and by exposing it to experimental checks in a way we have devised in this program we can either say, in what way the leptoquark scenario should be realized, or we can conclude that leptoquarks are not an acceptable hypothesis.
The mechanism of particle mass origin lies at the center of attention of particle physics. It is a fundamental ontological question for which we are starting to get a clear physical answer with the discovery of the Higgs boson. After its discovery and the confirmation of the SM, the question of neutrino mass remains as the logical next step in the evolution of scientific understanding. A lot of theoretical and phenomenological progress will be needed towards solving this puzzle. Detailed studies of signals at colliders and precision experiments are urgent in order to take full advantage of available data, design future experiments and open new directions on the theory front. Progress in this direction would clearly constitue an important contribution to basic science.
Non-perturbative methods are potentially applicable in different fields
Significance for the country
The pioneering results on the proposed physics problems will undoubtedly promote reputation of Slovenian scientists and the country as a whole. The number of invited talks on the related results over the past few years indicate that Slovenian scientists share a leading role on topics like hadron spectroscopy, Higgs physics, flavor physics and theories of unification. It is expected that this trend will continue with the forthcoming results from the proposed studies.
Results of the research program will be of immediate high relevance for the experimental high energy physics groups at the F-9 department of the Jozef Stefan Institute, which are involved in the ATLAS experiment at the LHC as well as the Belle II experiment at the super flavor factory Super KEK-B. Through the direct cooperation and idea exchange they will namely continue to obtain an important competitive advantage compared to similar experimental groups abroad in the execution of the new suggested measurements, which
could be key in the unfolding of new physics affecting the electroweak symmetry breaking or quark flavor generation.
The proposed research program is introducing an important bridge between the studies of low energy measurements of flavour and CP violation, which are already well established in Slovenia, hadronic physics at LHC energies, which has until recently not been studied
theoretically in Slovenia at all, and has been introduced by our group during the last financing period, and also particle phenomenology in the current and early universe, which is recently becoming increasingly important world-wide for the development of high energy physics in general. For this purpose we shall maintain and strengthen existing successful collaborations with other centers of theoretical high energy physics abroad (e.g. CERN, INFN, LPT Orsay, DESY, ICTP, T.U. Munich, Max Planck Inst., Univ. Valencia, Univ. Barcelona, Univ. Cincinnati, Weizmann inst., LBNL, Harvard Univ.).
The field of high energy physics is specific in science due to large and expensive experimental equipment, and has grown to an international enterprise that aims at understanding of physics at the smallest accessible scales. The country taking part in this enterprise can actively stimulate the progress in fundamental physics (in form of funding and people resources) and at the same time profits from exchange of new knowledge between local scientists and the international community, a process that has positive impact on the quality of knowledge that is passed to next generations at universities and schools.
The CFHHM (Correlation Function Hyperspherical Harmonic Method) code is an example of efficient use of infrastructure as it can be made to run in parallel by changing a few lines of code.
Based on computer reconstruction of several aircraft accidents and incidents for the Ministry of Defense one of the program researchers serves as expert in the Aircraft Accident & Incident Investigation Board of the MoD by decree of Minister No. 8042-73/2012-18 dated 08/24/2012.
Most important scientific results
Annual report
2015,
2016,
2017,
final report
Most important socioeconomically and culturally relevant results
Annual report
2015,
2016,
2017,
final report
