Measurement of tan beta in associated t H^\pm Production in gamma gamma Collisions

The ratio of neutral Higgs field vacuum expectation values, tan beta, is one of the most important parameters to determine in type-II Two-Higgs Doublet Models (2HDM), specifically the Minimal Supersymmetric Standard Model (MSSM). Assuming the energies and integrated luminosity of a future high energy e^+e^- linear collider of sqrt{s}=500, 800, 1000, and 1500 GeV and L=1 ab^{-1} we show that associated t H^+/- production in gamma gamma collisions can be used to make an accurate determination of tan beta for low and high tan beta by precision measurements of the gamma gamma -> H^+/- t + X cross section.Comment: 7 pages, 11 figures, uses REVTEX

Health and the Economy : a statement of concern

The relationship between health and the economy is an intimate and complex one. The economy of health and the apportioning of funds to different medical services and health care programs are issues that depend on the health profile of a given community as well as the expectations of its members. Decisions ultimately depend on available resources and political priorities. Health and the economy cannot be isolated and contrasted, as the integrity of a given economic system clearly depends on the state of health of the community both at an individual level as well as at a population level.peer-reviewe

Higgs Boson Production in gamma-gamma Collisions via Resolved Photon Contributions

We studied single Higgs boson production in $\gamma\gamma$ collisions proceeding via the hadronic content of the photon. For SM Higgs masses of current theoretical interest, the resolved photon contributions are non-negligible in precision cross section measurements. We found that production of the heavier Higgs bosons H^0 and A^0 of the MSSM can probe regions of the SUSY parameter space that will complement other measurements. Finally, we showed that associated t H^\pm production in gamma-gamma collisions can be used to make an accurate determination of tan(beta) for low and high tan(beta)by precision measurements of the gamma gamma to H^\pm t +X cross section.Comment: 3 pages, contributed talk to the 2004 DPF Meeting, Riverside CA, Aug 26-31, 2004, Uses ws-ijmpa.cl

Production of the h_c and h_b and Implications for Quarkonium Spectroscopy

The recent observation of the h_c is an important test of QCD calculations and provides constraints on models of quarkonium spectroscopy. In this contribution I discuss some of these implications and describe methods to search for the h_c and h_b via radiative transitions and other means.Comment: Talk presented at the 1st Meeting of the APS Topical Group on Hadronic Physics (Fermilab, Oct 24-26, 2004), 4 pages, 1 figure, uses jpconf. References adde

Properties of the Strange Axial Mesons in the Relativized Quark Model

We studied properties of the strange axial mesons in the relativized quark model. We calculated the $K_1$ decay constant in the quark model and showed how it can be used to extract the $K_1 (^3P_1) - K_1 (^1P_1)$ mixing angle ($\theta_K$) from the weak decay $\tau \to K_1 \nu_\tau$. The ratio $BR(\tau \to \nu_\tau K_1 (1270))/BR(\tau\to \nu_\tau K_1(1400))$ is the most sensitive measurement and also the most reliable since the largest of the theoretical uncertainties factor out. However the current bounds extracted from the TPC/Two-Gamma collaboration measurements are rather weak: we typically obtain $-30^o \lesssim \theta_K \lesssim 50^o$ at 68\% C.L. We also calculated the strong OZI-allowed decays in the pseudoscalar emission model and the flux-tube breaking model and extracted a $^3P_1 - ^1P_1$ mixing angle of $\theta_K \simeq 45^o$. Our analysis also indicates that the heavy quark limit does not give a good description of the strange mesons.Comment: Revised version to be published in Phys. Rev. D. Minor changes. Latex file uses revtex version 3 and epsfig, 4 postcript figures are attached. The full postcript version with embedded figures is available at ftp://ftp.physics.carleton.ca/pub/theory/godfrey/ocipc9512.ps.

Spectroscopy of B_c Mesons in the Relativized Quark Model

We calculate the spectrum of the charm-beauty mesons using the relativized quark model. Using the wavefunctions from this model we compute the radiative widths of excited c\bar{b} states. The hadronic transition rates between c\bar{b} states are estimated using the Kuang-Yan approach and are combined with the radiative widths to give estimates of the relative branching ratios. These results are combined with production rates at the Tevatron and the LHC to suggest promising signals for excited B_c states. Our results are compared with other models to gauge the reliability of the predictions and point out differences.Comment: 15 pages, 1 fig. uses revtex4. References adde

The Exotic XYZ Charmonium-like Mesons

Charmonium, the spectroscopy of c\bar{c} mesons, has recently enjoyed a renaissance with the discovery of several missing states and a number of unexpected charmonium-like resonances. The discovery of these new states has been made possible by the extremely large data samples made available by the B-factories at the Stanford Linear Accelerator Center and at KEK in Japan, and at the CESR e^+e^- collider at Cornell. Conventional c\bar{c} states are well described by quark potential models. However, many of these newly discovered charmonium-like mesons do not seem to fit into the conventional c\bar{c} spectrum. There is growing evidence that at least some of these new states are exotic, i.e. new forms of hadronic matter such as mesonic-molecules, tetraquarks, and/or hybrid mesons. In this review we describe expectations for the properties of conventional charmonium states and the predictions for molecules, tetraquarks and hybrids and the various processes that can be used to produce them. We examine the evidence for the new candidate exotic mesons, possible explanations, and experimental measurements that might shed further light on the nature these states.Comment: 28 pages, 7 figures. Review for Ann Rev Nucl & Part Sc