Related papers: Long-Lived Quarks?
For a long time it has been established both experimentally and theoretically that $\Omega_c^0$ is shortest-lived among the four singly charmed baryons which decay weakly. The situation was dramatically changed in 2018 when LHCb reported a…
To obtain an exact solution of a four-body system containing two quarks and two antiquarks interacting through two-body terms is a cumbersome task that has been tackled with more or less success during the last decades. We present an exact…
There are several reasons to believe that some of the new particles observed at B-factories have no ordinary quark composition. We briefly illustrate the diquark-antidiquark model and the recent experimental discoveries which confirm some…
We investigate the modifications to predictions for the abundances of light elements from standard Big-Bang nucleosynthesis when exotic late-decaying particles with lifetimes exceeding ~1 sec are prominent in the early Universe. Utilising a…
We study the implications of a large degree of compositeness for the light generation quarks in composite pseudo-Nambu-Goldstone-boson Higgs models. We focus in particular on viable scenarios where the right-handed up-type quarks have a…
Some of the means through which the possible presence of nearly deconfined quarks in neutron stars can be detected by astrophysical observations of neutron stars from their birth to old age are highlighted.
Recent results in the decays of the heavy quarks, bottom and charm, are reviewed.
Some of the currently most popular conjectures for the structure of the recently discovered heavy mesons that do not find a place in the quark model quarkonium spectrum are sketched. Furthermore, some observables are identified that should…
Superheavy particles of masses $\simeq 10^{13}-10^{14} GeV$ with lifetimes $\simeq 10^{10}-10^{22} years$ are very interesting, since their decays may account for the ultra-high energy (UHE) cosmic rays discovered beyond the…
Our world is wonderful because of the normal but negligibly small baryonic part (i.e., atoms) although unknown dark matter and dark energy dominate the Universe. A stable atomic nucleus could be simply termed as ``strong matter'' since its…
We show that QCD contains stable four-quark QQ\qbar\qbar hadronic states in the limit where the heavy quark mass goes to infinity. (Here Q denotes a heavy quark, \qbar a light antiquark and the stability refers only to the strong…
A mechanism to have the quark mass hierarchy in the supersymmetric composite model is proposed. The source of the hierarchy is the kinetic-term mixing between composite quarks. Such mixing can be expected, if quarks are composite particles.…
Narrow high-mass states can arise despite large phase space when two nearly degenerate states are coupled to the same dominant decay mode. Mixing via a final-state interaction loop diagram can produce one very broad state and one narrow…
Several theories beyond the Standard Model (BSM) predict heavy neutral leptons, or long-lived particles with unique signatures which are difficult to reconstruct. Another area of interest are vector-like quarks which lie at the heart of…
Condensates of colored fermions driving electroweak symmetry breaking could give rise to a light pseudoscalar that would show up in the Higgs search at the LHC. The branching ratios of its decay will distinguish it from the Higgs and…
The old issue of why there are more than one family of quarks and leptons is reinvestigated with an eye towards the use of anomaly as a tool for constraining the number of families. It is found that, by assuming the existence of…
Very little is known about the mass spectrum of fermions in the standard model. In this talk, I point out that in the simplest extension of the standard model, in which all right-handed fields are singlets, it is quite possible that a…
The potential of decays of mesons containing heavy quarks [including $B$ mesons and the $\Upsilon(1S)$] for producing final states of matter with unusual quark configurations, such as $q q \bar q \bar q$ or $q q q q \bar q$, is…
Ordinary technicolor and extended technicolor cannot produce the heavy top quark unaided. We demonstrate that a flavor-universal extension of the color interactions combined with an extended hypercharge sector that singles out the third…
Superstring theory predicts the existence of relic metastable particles whose average lifetime is longer than the age of the universe and which could, in principle, be good dark matter candidates. At the same time, these states would be…