Related papers: New quarks: exotic versus strong
We introduce a new class of models describing the quark mass hierarchy. In this class, the dynamics primarily responsible for electroweak symmetry breaking (EWSB) leads to the mass spectrum of quarks with no (or weak) isospin violation.…
As the heaviest known fundamental particle, the top quark has taken a central role in the study of fundamental interactions. Production of top quarks in pairs provides an important probe of strong interactions. The top quark mass is a key…
Bound states of heavy $\bar{q}q$ quarks are reviewed within the context of QCD, paying attention to what can be derived from the theory with a reasonable degree of rigour. This is compared with the results of semiclassical arguments. Among…
We consider the possibility that quarks and gluons, due to confinement, have lower scaling dimensions. In such a case there appear naturally new energy scales below which the standard theory is recovered. Arguments are given whereby for…
We explore constraints on various new physics resonances from four top-quark production based on current experimental data. Both light and heavy resonances are studied in the work. A comparison of full width effect and narrow width…
The new approach to decays of heavy quarkonia, based on factorization and expansions in powers of the relative velocity of the valence quarks is reviewed.
Studies of exotic hadrons such as the $\chi_{cl}(3872)$ state provide crucial insights into the fundamental force governing the strong interaction dynamics, with an emerging new frontier to investigate their production in high energy…
In this paper the masses and decay processes of several new strange, charmed and bottomed exotic pentaquarks are predicted. Multiquarks are studied microscopically in a standard quark model. In pure ground-state pentaquarks the short-range…
Exotic interactions between fermions mediated by new bosons beyond the Standard Model may hold the key to several fundamental conundrums on the frontier of physics.However, laboratory searching for exotic interactions on small length scales…
The strongly repulsive core of the short-range nucleon-nucleon interaction leads to the existence of high-momentum nucleons in nuclei. Inclusive electron scattering can be used to probe these high-momentum nucleons and study the nature of…
The existence of new quarks may lead to their mixing with ordinary quarks. We are particularly interested in studying the consequences such mixings could have upon the electromagnetic current. We find that new strong flavor and parity…
Recent achievements in nuclear forces theory open new perspectives for the next decade of low energy nuclear physics, bringing together people from very different communities. Although many developments remain to be done, the possibility to…
The necessity of the fourth family follows from the SM basics. According to flavor democracy the Dirac masses of the fourth SM family fermions are almost equal with preferable value 450 GeV, which corresponds to common (for all fundamental…
The existing bounds from CDF on the masses of the fourth generation quarks, t' and b', are reexamined. The bound of 256 GeV on the t' mass assumes that the primary decay of the t' is into q+W, which is not the case for a substantial region…
The extension of the standard model with pairs of the vector-like families is studied. The quark mixing matrices for the left- and right-handed charged currents, as well as those for the flavour changing neutral currents, the Z and Higgs…
According to the hypothesis that strange quark matter may be the true ground state of matter at extremely high densities, strange quark stars should be stable and could exist in the Universe. It is possible that pulsars may actually be…
The search for new interactions of neutrinos beyond those of the Standard Model may help to elucidate the mechanism responsible for neutrino masses. Here we combine existing accelerator neutrino data with restrictions coming from a recent…
We consider the interactions in a mesonic system, referred here to as `tetron', consisting of two heavy quarks and two lighter antiquarks (which may still be heavy in the scale of QCD), i.e. generally $Q_a Q_b \bar q_c \bar q_d$, and study…
Flavour changing neutral currents arise in the $SU(3)_c\otimes SU(4)_L\otimes U(1)_X$ extension of the standard model because anomaly cancellation among the fermion families requires one generation of quarks to transform differently from…
In most of the proposals for new physics beyond the standard model, neutrinos have new interactions and some of them have phenomenological consequences that, although at present they may seem purely academic, probably will have to be taken…