arXiv subjects

Michael S. Chanowitz

Publications and source records attributed to Michael S. Chanowitz.

24 records · Page 2Linked to original sources

arXiv1995

Strong WW scattering in unitary gauge

A method to embed models of strong $WW$ scattering in unitary gauge amplitudes is presented that eliminates the need for the effective $W$ approximation (EWA) in the computation of cross sections at high energy colliders.The cross sections obtained from the U-gauge amplitudes include the distributions of the final state fermions in $ff \rightarrow ffWW$, which cannot be obtained from the EWA. Since the U-gauge method preserves the interference of the signal and the gauge sector background amplitudes, which is neglected in the EWA, it is more accurate, especially if the latter is comparable to or bigger than the signal, as occurs for instance at small angles because of Coulomb singularities. The method is illustrated for on-shell $W^+W^+ \rightarrow W^+W^+$ scattering and for $qq \rightarrow qqW^+W^+$.

hep-ph↗

arXiv1995

Probing for Ultraheavy Quanta at LHC

Experiments at the LHC are sensitive to the presence or absence of matter quanta at mass scales far beyond the scales they can probe directly. The production of $Z$ boson pairs by gluon-gluon fusion is greatly enhanced if there are ultraheavy quanta that carry $SU(3)_{\rm Color}$ and get their mass from electroweak symmetry breaking. For example, a fourth generation quark doublet with an arbitrarily heavy mass would induce a large excess in the $ZZ$ yield that could be detected at the LHC with only $\simeq 10\%$ of the design luminosity.

hep-ph↗

arXiv1994

$W^+Z$ and $W^+γ^*$ Backgrounds to Strong $W^+W^+$ Scattering at the LHC

Because of inevitable blind spots at high rapidity and low transverse momentum, the process $\overline qq \rightarrow l^+ l^- \ l^{+} ν$ provides a surprisingly large background to the $W^+W^+ \rightarrow l^+ ν\ l^+ ν$ signal associated with strong $WW$ scattering. Previous calculations of the total background are approximately doubled, and the estimate of the ``no-lose'' luminosity at the LHC to observe manifestations of the electroweak symmetry breaking mechanism is increased to between $\sim 100$ and $\sim 140$ fb$^{-1}$.

hep-ph↗

arXiv1994

Physics at High Energy Photon Photon Colliders

I review the physics prospects for high energy photon photon colliders, emphasizing results presented at the LBL Gamma Gamma Collider Workshop. Advantages and difficulties are reported for studies of QCD, the electroweak gauge sector, supersymmetry, and electroweak symmetry breaking.

hep-ph↗

arXiv1993

Complementarity of Resonant and Nonresonant Strong $WW$ Scattering at the LHC

We exhibit a complementary relationship between resonant $WZ$ and nonresonant $W^+W^+$ scattering in a chiral Lagrangian model of the electroweak symmetry breaking sector with a dominant ``$ρ$'' meson. We use the model to estimate the minimum luminosity for the LHC to ensure a ``no-lose'' capability to observe the symmetry breaking sector.

hep-ph↗

arXiv1993

The Trace Anomaly in Chiral Dynamics: $γγ\to π^0π^0$ Scattering

The trace anomaly term in the low energy chiral Lagrangian is established by deriving a low energy theorem for $γγ\rightarrow π^0π^0$ scattering. It contributes to $σ(γγ\rightarrow π^0π^0)$ in the same order as the previously computed pion loop contribution. The coherent sum of the two contributions explains the shape of the measured cross section, while the magnitude is determined by the anomalous dimension of the quark mass operator.

hep-ph↗