Leptoquarks arise naturally in models attempting the unification of the quark and lepton sectors of the standard model of particle physics. Such particles could be produced in the interaction of high energy quasi-horizontal cosmic neutrinos with the atmosphere, via their direct coupling to a quark and a neutrino. The hadronic decay products of the leptoquark, and possibly its leptonic decay pro...

A heavy quark effective field lagrangian keeping particle and antiparticle mixed sectors * Abstract We examine the applicability of the heavy-quark effective field theory (HQEFT) to heavy quark-antiquark pair annihilation or creation processes. To this end, we keep the particle-antiparticle sector in the inverse heavy-quark mass expansion of the HQEFT Lagrangian. We show that by removing the la...

We reconsider the massless up quark solution of the strong CP problem. We show that an anomaly free horizontal symmetry can naturally lead to a massless up quark and to a corresponding accidental anomalous symmetry. Reviewing the controversy about the phenomenological viability of m u = 0 we conclude that this possiblity is still open and can solve the strong CP problem.

We show that solutions for the masses and mixings of the quarks and leptons based on a U (1)×Z 2 horizontal symmetry are possible. The seesaw mechanism is shown to work consistently in the presence of the discrete symmetry. The discrete symmetry results in the phenomenologically useful suppressions of elements of the Yukawa matrices. The quark and lepton masses, the CKM mixing angles, and the n...

We review some recent results on heavy quark production in high energy hadronic collisions. We will discuss in particular the status of production cross sections for bottom quarks and charmonium states and will present some studies on the production of bottom and charm jets, at the inclusive level and in association with electroweak gauge bosons.

It is shown that the quark–gluon interaction induced by instan-tons leads to the quark anomalous chromomagnetic moment. In the instanton-liquid model for the QCD vacuum, the chromomagnetic moment is µ a = − πf 2αs , where f is the packing fraction of instantons in the vacuum.

Considering cold, dense quark matter with two massless quark flavors, we demonstrate how, in a self-consistent calculation in the framework of QCD, the condensation of Cooper pairs induces a non-vanishing background color field. This background color field has precisely the right magnitude to cancel tadpole contributions and thus ensures overall color neutrality of the two-flavor color supercon...

A parametrization of the 3 × 3 Cabibbo-Kobayashi-Maskawa matrix, V , is presented in which the parameters are the eigenvalues and the components of its eigenvectors. In this parametrization, the small departure of the experimentally determined V from being moduli symmetric (i.e. |Vij | = |Vji|) is controlled by the small difference between two of the eigenvalues. In case, any two eigenvalues ar...

To explain the T-T' mass splitting of the recently discovered T resonances, we interpret them as bound states of a quark and an antiquark which are not members of the fundamental (2) representation of color SU(2). A quark in the 8 (or maybe 5) representation is consistent with the data. We discuss some of its properties and the phenomenological consequences that follow from our suggestion. (Sub...

In particular calculations have been made for the detection of extraterrestrial high energy neutrinos. Additional the rest-energy of a neutrino is calculated (equivalent to its rest mass). But both calculations are not standard. The calculations are made from the perspective of a new model for the universe: The Double Torus hypothesis. The alternative calculation shows that the result matches a...