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...

Small momentum transfer elastic pion-proton cross-section at high energies is calculated assuming the proton is composed of two constituents, a quark and a diquark. We find that it is possible to fit very precisely the data when (i) the pion acts as a single entity (no constituent quark structure) and (ii) the diquark is rather large, comparable to the size of the proton.

The high energy physics program (Ecms ≤ 8.6GeV ) at DORIS was initiated by the PLUTO collaboration which sent its proposal to the Forschungskollegium June 30, 1977 [1]. The same day the observation of the Υ(9.46) resonance was announced to the public in a seminar at FNAL [2]. The physics program proposed by PLUTO included the measurement of σtot and the search for charm and τ . The search for a...

A seesaw mass matrix model is reviewed as a unification model of quark and lepton mass matrices. The model can understand why topquark mass mt is so singularly enhanced compared with other quark masses, especially, why mt ≫ mb in contrast to mu ∼ md, and why only top-quark mass is of the order of the electroweak scale ΛW , i.e., mt ∼ O(ΛW ). The model predicts the fourth up-quark t′ with a mass...

The method of calculation of effective vertices of interaction of the Reggeized gluon and quark with particles in QCD in the next-to-leading order is developed. The method is demonstrated in the case of already known vertices of both gluon-gluon and quark-quark transitions in the scattering of gluons and quarks on the Reggeized gluon. It is used for the calculation of the gluon-quark transition...

In this talk, a supersymmetric (SUSY) composite model of color superconductivity is discussed. In this model, quark and diquark supermultiplets are dynamically generated as massless composites by a newly introduced confining gauge dynamics. It is analytically shown that the scalar component of diquark supermultiplets develops vacuum expectation value (VEV) at a certain critical chemical potenti...

Single-lepton plus jets signals from t ¯ t production at hadron colliders generally give more spherically symmetrical events than the principal backgrounds from W production. We show that sphericity and aplanarity criteria, applied to lepton plus neutrino plus four jet final states at the Fermilab Tevatron p¯ p collider, help to discriminate; they can be used either to validate an eventual top ...