The lattice QCD results on the hadron spectrum and weak transitions between hadrons are briefly reviewed. Hadrons containing heavy quarks c or b are considered. The focus is on the recent simulations and some older results which are particularly relevant in view of the recent experimental discoveries.
B.04 Guest lecture
COBISS.SI-ID: 3156068Invited plenary lecture at the 3rd International Symposium, on "Quest for the Origin of Particles and the Universe", KMI 2017, 5-7 January 2017, Nagoya.
B.04 Guest lecture
COBISS.SI-ID: 30953255Phenomenologically appealing supersymmetric grand unified theories have large gauge representations and thus are not asymptotically free. Their ultraviolet validity is limited by the appearance of a Landau pole well before the Planck scale. One could hope that these theories save themselves, before the inclusion of gravity, by generating an interacting ultraviolet fixed point, similar to the one recently discovered in non-supersymmetric gauge-Yukawa theories. Employing a-maximization, a-theorem, unitarity bounds, as well as positivity of other central charges we nonperturbatively rule out this possibility for a broad class of prime candidates of phenomenologically relevant supersymmetric grand unified theories. We also uncover candidates passing these tests, which have either exotic matter or contain one field decoupled from the superpotential. The latter class of theories contains a model with the minimal matter content required by phenomenology.
B.04 Guest lecture
COBISS.SI-ID: 31028775Leptoquarks are hypothetical particles interacting with quarks and leptons. They can be scalar or vector particles. They naturally appear at GUT scale. In the case that their masses are in TeV region they can contribute to processes at low energies. Among leptoquarks most likely to mediate processes at low energies are two doublets of weak interaction, which do not mediate proton decay. Their most important role is that they can explain B meson anomalies RD(*) and RK(*). In the ratio of decay widths B decay to D (*) tau nu and B decay to D (*) muon nu named RD(*), contribution of the charge currents should be modified by the physics beyond the Standard Model. The ratio RK(*) denotes the ratio of the decay widths for the flavour changing neutral currents processes B to K(*) mu+ mu- and B to K(*) e+ e-. Leptoquark contributions might account for the observed deviations of the Standard Model predictions.
B.04 Guest lecture
COBISS.SI-ID: 3109988Many models of neutrino masses feature an extended Higgs sector with additional scalars that may be present at the TeV scale and provide distinctive collider signals. In the talk, I provided a review of recent studies of some of such models, covered their observability potential at present and future colliders.
B.04 Guest lecture
COBISS.SI-ID: 30996263