This paper is a review of recent lattice determinations of the light quark masses. It describes the method employed to calculate quark masses in the lattice formulation, and the extrapolations required to reach the physical regime. This review is designed to be accessible to a general audience, not specifically lattice theorists.

The available experimental information is consistent with the Weinberg predictions for the threshold parameters of ππ-scattering. The data, however, only test those relations that are insensitive to the quark masses mu and md. Recent theoretical progress leads to remarkably sharp predictions for the behaviour of the Sand P-wave phase shifts in the elastic region – one of the very few low energy...

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...