Reply to Comment on "Chiral suppression of scalar glueball decay"

Reply to the comment of Chao, He, and Ma

Strong WWWW scattering at the end of the 90's: theory and experimental prospects

The nature of electroweak symmetry breaking can only be established definitively by the direct discovery and detailed study of the symmetry breaking quanta at high energy colliders. At the LHC the ability to observe TeV scale strong WW scattering confers a no-lose capability to establish the mass scale and interaction strength of the symmetry breaking quanta, even if the symmetry breaking quanta resist discovery and whether strong WW scattering is observed or excluded. This lecture discusses the motivation to consider strong WW scattering in light of what we have learned from precision electroweak data during the decade. The theoretical basis for strong WW scattering is explained with an introductory review of the Higgs mechanism from a general perspective that encompasses light, perturbative Higgs bosons or nonperturbative, dynamical symmetry breaking by TeV scale strong interactions. The experimental signals and backgrounds are reviewed and the sensitivity of experiments at the LHC is assessed

Higgs boson mass constraints from precision data and direct searches

Two of the nine measurements of $sin^{2}\theta^{lepton}_{eff}$, the effective weak interaction mixing angle, are found to be in significant conflict with the direct search limits for the Standard Model (SM) Higgs boson. Using a scale factor method, analogous to one used by the Particle Data Group, we assess the possible effect of these discrepancies on the SM fit of the Higgs boson mass. The scale factor fits increase the value of $sin^{2}\theta^{lepton}_{eff}$ by as much as two standard deviations. The central value of the Higgs boson mass increases as much as a factor of two, to $\simeq 200$ GeV, and the 95% confidence level upper limit increases to as much as 750 GeV. The scale factor is based not simply on the discrepant measurements, as was the case in a previous analysis, but on an aggregate goodness-of-fit confidence level for the nine measurements and the limit. The method is generally applicable to fits in which one or more of a collection of measurements are in conflict with a physical boundary or limit. In the present context, the results suggest caution in drawing conclusions about the Higgs boson mass from the existing data

Combining real and virtual Higgs boson mass constraints

Within the framework of the standard model we observe that there is a significant discrepancy between the most precise $Z$ boson decay asymmetry measurement and the limit from direct searches for Higgs boson production. Using methods inspired by the Particle Data Group we explore the possible effect on fits of the Higgs boson mass. In each case the central value and the 95% confidence level upper limit increase significantly relative to the conventional fit. The results suggest caution in drawing conclusions about the Higgs boson mass from the existing data.Comment: 11 pages, Latex. Citations are added and paper is otherwise reconciled with version to be published in Physical Review Letter

Eliminating the low-mass axigluon window

Using recent collider data, especially on the hadronic width the Z0, we exclude axigluons in the currently allowed low-mass window, namely axigluons in the mass range 50 GeV < M_A < 120 GeV. Combined with hadron collider data from di-jet production, axigluons with masses below roughly 1 TeV are now completely excluded.Comment: 8 pages, no figures, LaTe

Inelastic Channels in WW Scattering

If the electroweak symmetry-breaking sector becomes strongly interacting at high energies, it can be probed through longitudinal $W$ scattering. We present a model with many inelastic channels in the $W_L W_L$ scattering process, corresponding to the production of heavy fermion pairs. These heavy fermions affect the elastic scattering of $W_L$'s by propagating in loops, greatly reducing the amplitudes in some charge channels. We conclude that the symmetry-breaking sector cannot be fully explored by using, for example, the $W_L^\pm W_L^\pm$ mode alone, even when no resonance is present; all $W_L W_L \to W_L W_L$ scattering modes must be measured.Comment: phyzzx, 13 pp. plus 4 figures, JHU-TIPAC-930005, MSUHEP-93/0

The Indirect Limit on the Standard Model Higgs Boson Mass from the Precision FERMILAB, LEP and SLD Data

Standard Model fits are performed on the most recent leptonic and b quark Z decay data from LEP and SLD, and FERMILAB data on top quark production, to obtain $m_t$ and $m_H$. Poor fits are obtained, with confidence levels $\simeq$ 2%. Removing the b quark data improves markedly the quality of the fits and reduces the 95% CL upper limit on $m_H$ by $\simeq$ 50 GeV.Comment: 6 pages 3 tables i figur

Detection of the heavy Higgs boson at γγ\gamma\gamma colliders

We consider the possibility of detecting a heavy Higgs boson ($m_H>2m_Z$) in proposed $\gamma\gamma$ colliders through the semi-leptonic mode $\gamma\gamma \rightarrow H \rightarrow ZZ \rightarrow q\bar q \ell^+\ell^-$. We show that due to the non-monochromatic nature of the photon beams produced by the laser-backscattering method, the resultant cross section for Higgs production is much smaller than the on-resonance cross section and generally {\it decreases} with increasing collider energy. Although continuum $ZZ$ production is expected to be negligible, we demonstrate the presence of and calculate sizeable backgrounds from $\gamma\gamma\rightarrow \ell^+\ell^-Z,\,q\bar qZ$, with $Z\rightarrow q\bar q,\,\ell^+\ell^-$, respectively, and $\gamma\gamma\rightarrow t\bar t\rightarrow b\bar b\ell^+\ell^-\nu\bar\nu$. This channel may be used to detect a Higgs of mass $m_H$ up to around 350~GeV at a 0.5~TeV $e^+e^-$ collider, assuming a nominal yearly luminosity of 10--20~fb$^{-1}$.Comment: 18 pages (in RevTeX) plus Postscript figures (available by email or FAX), NUHEP-TH-92-29 and DOE-309-CPP-47. (Revised version: NO CHANGES to the manuscript, simply removed corrupted figure files

Bloch-Nordsieck Violation in Spontaneously Broken Abelian Theories

We point out that, in a spontaneously broken U(1) gauge theory, inclusive processes, whose primary particles are mass eigenstates that do not coincide with the gauge eigenstates, are not free of infrared logarithms. The charge mixing allowed by symmetry breaking and the ensuing Bloch-Nordsieck violation are here analyzed in a few relevant cases and in particular for processes initiated by longitudinal gauge bosons. Of particular interest is the example of weak hypercharge in the Standard Model where, in addition, left-right mixing effects arise in transversely polarized fermion beams.Comment: 4 pages, 1 figur

Surface Tension at Finite Tempearture in the MIT Bag Model

At $T = 0$ the surface tension $\sigma ^{1/3}$ in the MIT bag model for a single hadron is known to be negligible as compared to the bag pressure $B^{1/4}$. We show that at finite temperature it has a substantial value of 50 - 70 MeV which also differ from hadron to hadron. We also find that the dynamics of the Quark-Gluon Plasma is such that the creation of hybrids $(s\bar{s}g)$ with massive quarks will predominate over the creation of $(s\bar{s})$ mesons.Comment: Substantial changes in the revised version and a new author included, 13 pages in Latex and one figur