Oscar F. Hernandez

Decays of B mesons to two light pseudoscalars

The decays [ital B][r arrow][ital PP], where [ital P] denotes a light pseudoscalar meson, are analyzed. Numerous triangle relations for amplitudes hold within flavor SU(3) symmetry, relating (for example) the decays [ital B][sup +][r arrow][pi][sup +][pi][sup 0], [pi][sup 0][ital K][sup +], and [pi][sup +][ital K][sup 0]. Such relations can improve the possibilities for learning about phases of the Cabibbo-Kobayashi-Maskawa (CKM) matrix and for early detection of [ital CP]-violating asymmetries. Within the context of a graphical analysis of decays, relations are analyzed among SU(3) amplitudes which hold if some graphs are neglected. These relations allow the determination of weak and strong phases from rate measurements alone. Estimates of SU(3) breaking are included.

Electroweak penguin diagrams and two-body B decays.

We discuss the role of electroweak penguin diagrams in {ital B} decays to two light pseudoscalar mesons. We confirm that the extraction of the weak phase {alpha} through the isospin analysis involving {ital B}{r_arrow}{pi}{pi} decays is largely unaffected by such operators. However, the methods proposed to obtain weak and strong phases by relating {ital B}{r_arrow}{pi}{pi}, {ital B}{r_arrow}{pi}{ital K}, and {ital B}{r_arrow}{ital K{bar K}} decays through flavor SU(3) will be invalidated if eletroweak penguin diagrams are large. We show that, although the introduction of electroweak penguin contributions introduces no new amplitudes of flavor SU(3), there are a number of ways to experimentally measure the size of such effects. Finally, using SU(3) amplitude relations we present a new way of measuring the weak angle {gamma} which holds even in the presence of electroweak penguin diagrams.

Lepton masses in an SU ( 3 ) L ⊗ U ( 1 ) N gauge model

The

Decays of B mesons to two pseudoscalars in broken SU(3) symmetry.

SU(3)_c\otimes SU(3)_L\otimes U(1)_N

Particle production in a hadron collider rapidity gap: The Higgs case

model of Pisano and Pleitez extends the Standard Model in a particularly nice way, so that for example the anomalies cancel only when the number of generations is divisible by three. The original version of the model has some problems accounting for the lepton masses. We resolve this problem by modifying the details of the symmetry breaking sector in the model.

Measuring strong and weak phases in time independent B decays

The decays of

Feigin-Fuchs derivation of SU(1,1) parafermion characters

B

Central exclusive production of dijets at hadronic colliders

mesons to two-body hadronic final states are analyzed within the context of broken flavor SU(3) symmetry, extending a previous analysis involving pairs of light pseudoscalars to decays involving one or two charmed quarks in the final state. A systematic program is described for learning information {}from decay rates regarding (i) SU(3)-violating contributions, (ii) the magnitude of exchange and annihilation diagrams (effects involving the spectator quark), and (iii) strong final-state interactions. The implication of SU(3)-breaking effects for the extraction of weak phases is also examined. The present status of data on these questions is reviewed and suggestions for further experimental study are made.

NRQCD matrix elements in polarization of J / Psi produced from b decay

Production of rare particles within rapidity gaps has been proposed as a background-free signal for the detection of new physics at hadron colliders. No complete formalism accounts for such processes yet. We study a simple lowest-order QCD model for their description. Concentrating on Higgs production, we show that the calculation of the cross section pp → ppH can be embedded into existing models which successfully account for diffractive data. We extend those models to take into account single- and double-diffractive cross sections pp → HX1X2 with a gap between the fragments X1 and X2. Using conservative scenarios, we evaluate the uncertainties in our calculation, and study the dependence of the cross section on the gap width. We predict that Higgs production within a gap of 4 units of rapidity is about 0.3 pb for a 100 GeV Higgs at the Tevatron, and almost 2 pb for a 400 GeV Higgs within a gap of 6 units at the LHC with √s = 14 TeV.

Angular 21 cm power spectrum of a scaling distribution of cosmic string wakes

Abstract Flavor SU(3) symmetry implies certain relations among B -decay amplitudes to ππ , πK and K K final states, when annihilation-like diagrams are neglected. Using three triangle relations, we show how to measure the weak CKM phases α and γ using time-independent rate measurements only. In addition, one obtains all the strong final-state phases and the magnitudes of individual terms describing tree (spectator), color-suppressed and penguin diagrams. Many independent measurements of these quantities can be made with this method, which helps to eliminate possible discrete ambiguities and to estimate the size of SU(3)-breaking effects.