It is presented a critical consideration of all unusual properties of the scalar a 0 (980) and f 0 (980)-mesons in the four-quark, two-quark and molecular models. The arguments are adduced that the four-quark model is more preferable. It is discussed the complex of experiments that could finally resolve this issue.

The bottomonium and charmonium systems have long proved to be a rich source of QCD physics. Recent CLEO contributions in three disparate areas are presented: (1) the study of quark and gluon hadronization using Υ decays; (2) the interpretation of heavy charmonium states, including non-cc candidates; and (3) the exploration of light quark physics using the decays of narrow charmonium states as a...

A summary of some recent studies in jet physics is given. Topics include leading particle production in light flavor events in e + e − annihilations, an analytical treatment of gluon and quark jets at the next-to-next-to-next-to-leading order (3NLO), and various studies performed at LEP and HERA involving separated gluon and quark jets. 1 Leading particle production in separated light quark eve...

Introduction Implementation of Casemix system needs a well-organized and computerized system with well-trained and oriented staff, otherwise the system will fail. Improving knowledge and understanding of the funding system among staff and managers in hospitals and health systems can provide the groundwork for service improvements. The aim of this study was to evaluate the effectiveness of Intro...

It is presented a critical consideration of all unusual properties of the scalar a 0 (980) and f 0 (980)-mesons in the four-quark, two-quark and molecular models. The arguments are adduced that the four-quark model is more preferable. It is discussed the complex of experiments that could finally resolve this issue.

Expressions for the nucleon wave functions in the covariant spectator theory (CST) are derived. The nucleon is described as a system with a off-mass-shell constituent quark, free to interact with an external probe, and two spectator constituent quarks on their mass shell. Integrating over the internal momentum of the on-mass-shell quark pair allows us to derive an effective nucleon wave functio...

Assuming three light neutrinos and the seesaw mechanism we present a semiquantitative model of fermion masses based on (SUSY) SU(5) and abelian horizontal charges. A good description of the observed pattern of quark and lepton masses is obtained. For neutrinos we naturally obtain widely split masses and large atmospheric neutrino mixing as a consequence of SU(5)-related asymmetric mass matrices...

Many of the classic problems of particle physics appear in a very different light when viewed from the perspective of the multiverse. Most importantly the two great “fine tuning” problems that motivate the field are far less serious when one accounts for the required anthropic constraints which exist in a multiverse. However, the challenge then becomes to construct a realistic physical theory o...

We present some recent developments on model building for neutrino masses and mixings. In particular, we review tri-bimaximal neutrino mixing derived from discrete groups, notably A4. We discuss the problems encountered with extending the symmetry to the quark sector and with Grand Unification.

It is suggested that the narrow meson state seen in the the SELEX experiment is a (cs̄ss̄) tetraquark state. Characteristics of other possible tetraquarks formed out of c and s quarks and antiquarks are considered. SELEX experiment has reported [1] a puzzling narrow meson state at a mass of 2632.6± 1.6 MeV/c which decays preferentially to D s (cs̄) + η(548) rather than to D(cd̄)+K or D(cū)+K. In th...