Anomalous 4-Jet Events at LEP: a Signal of Low Scale Technicolour?

We propose that the 3.2 sigma excess at ~150 GeV in the dijet mass spectrum of W + jets reported by CDF is the technipion $\pi_T$ of low-scale technicolor. Its relatively large cross section is due to production of a narrow $Wjj$ resonance, the technirho, which decays to W + $\pi_T$. We discuss ways to enhance and strengthen the technicolor hypothesis and suggest companion searches at the Tevatron and LHC.

We discuss the phenomenology of an $SU(2)_{TC}$ technicolour model with a low technicolour confinement scale ${\Lambda}_{TC} \sim 50-100 GeV$. Such a low technicolour scale may give rise to the first hints of technicolour being seen at LEPI and spectacular technicolour signals at LEPII.

Strategies are presented for discovering light, color-singlet technipions (pi_T) produced in association with a vector boson through s-channel technirho production, at the Tevatron and LHC. Signal and W+jets background were simulated including detector effects. Tagging of b-quarks from the pi_T -> bb decay is found to be important to reduce the W+jets background. Kinematic properties of signal and background events are significantly different and simple cuts can be used to fu...

We catalog the principal signatures of electroweak and flavor dynamics at $\pbarp$ and $pp$ colliders for use at the 1996 Snowmass Workshop on New Directions in High Energy Physics. The framework for dynamical symmetry breaking we assume is technicolor, with a walking coupling $\atc$, and extended technicolor. The reactions discussed occur mainly at subprocess energies $\rshat \simle 1\,\tev$. They include production of color-singlet and octet technirhos and their decay into ...

This is the first of two reports cataloging the principal signatures of electroweak and flavor dynamics at $\pbarp$ and $pp$ colliders. Here, we discuss some of the signatures of dynamical elecroweak and flavor symmetry breaking. The framework for dynamical symmetry breaking we assume is technicolor, with a walking coupling $\alpha_{TC}$, and extended technicolor. The reactions discussed occur mainly at subprocess energies $\sqrt{\hat s} \simle 1 TeV$. They include production...

Lepton collider experiments can search for light technipions in final states made striking by the presence of an energetic photon: $e+e- \to \photon\technipion$. To date, searches have focused on either production through anomalous coupling of the technipions to electroweak gauge bosons or on production through a technivector meson (\technirho, \techniomega) resonance. This paper creates a combined framework in which both contributions are included. This will allow stronger a...

We briefly review the basic structure of modern--day technicolor theories. We then discuss the signatures for technicolor as they were in its early days, the searches that have been recently performed at the Tevatron and LEP colliders, and the prospects for testing technicolor in Tevatron Run II and at the LHC.

We discuss the phenomenology of the lightest SU(3)_C singlet and non-singlet technihadrons in the Straw Man Model of low-scale technicolor (TCSM). The technihadrons are assumed to be those arising in topcolor--assisted technicolor models in which topcolor is broken by technifermion condensates. We improve upon the description of the color--singlet sector presented in our earlier paper introducing the TCSM (hep-ph/9903369). These improvements are most important for subprocess ...

The simple "straw-man" model of low-scale technicolor contains light color--singlet technihadrons, which mix with the electroweak gauge bosons. We present lepton collider production rates at the parton level, and show that experiments at LEP2 may be sensitive to the presence of technirho and techniomega states with masses 10-20 GeV beyond the center-of-mass energy because of the mixing. The exact sensitivity depends on several parameters, such as the technipion mass, the tech...

Under the assumption that the dijet excess seen by the CDF Collaboration near 150 Gev in Wjj production is due to the lightest technipion of the low-scale technicolor process $\rho_T \rightarrow W \pi_T$, we study its observability in LHC detectors with 1--20 inverse femtobarns of data. We describe interesting new kinematic tests that can provide independent confirmation of this LSTC hypothesis. We find that cuts similar to those employed by CDF, and recently by ATLAS, cannot...