\begin{slide}{}
{\Large II. \underline{Physics}}
\begin{enumerate}
\item \underline{What is DCC?}
\begin{itemize}
\item Nearly Degenerate Strong-Interaction\\
 Vacuum ($\sim$ Higgs sector)
\item Spontaneously Broken\\
 Chiral Symmetry\\
$\sim$ Vacuum Order Parameter:
\begin{displaymath}
<\sigma>=<(\bar{u}_{L}u_{R} + \bar{d}_{L}d_{R} + h.c.)> \neq 0
\end{displaymath}
\item $\sigma$ Field $\sim$ Higgs Field
\item $\sim$ $\pi^{+}$, $\pi^{-}$, $\pi^{0}$\\
 Orientations of the $\sigma$ Field\\
($\sim$ Long. $W^{+}$, $W^{-}$, $Z^{0}$)
\begin{eqnarray}
\pi^{0}& = &(\bar{u}_{L}u_{R} - \bar{d}_{L}d_{R}) + h.c. \nonumber \\
\pi^{+}& = &(\bar{u}_{L}d_{R} + \bar{u}_{R}d_{L}) \nonumber \\
\pi^{-}& = &(\bar{d}_{L}u_{R} + \bar{d}_{R}u_{L}) \nonumber 
\end{eqnarray}
\end{itemize}
\vfill\eject


\item \underline{Possible Vacuum Order-Parameter}\\
\underline{Disorientation in Collision Fireballs}\\ 
\vspace{.25in}
Before Collision:\\
\vspace{.25in}
Frame with $45 \, GeV \rightarrow \leftarrow 18  \,TeV \,\bar{p}$\\
\vspace{.25in}

After Collision: See Figure $\longrightarrow$\\
\vspace{.50in}

Decay Products of Disoriented Vacuum
\begin{itemize}
\item Will Form a Pulse of Coherent\\
 Semi-Classical Pion Field
\item In a Given Event Will All Have the\\
 Same (Cartesian) Isospin Direction
\end{itemize}
\vfill\eject

\item \underline{Basic DCC Signature}\\
\begin{itemize}
\item Large Event-to-Event Fluctuations\\
in the Neutral Fraction f:
\begin{displaymath}
f = {{N_{\pi^{0}}} \over {N_{\pi^{0}}+N_{\pi^{+}}+N_{\pi^{-}}}}
\end{displaymath}
\vspace{.25in}
\item Random Orientation\\
of the Chiral-Order Parameter:
\begin{displaymath}
{{dN} \over {df}} = {{1} \over {2 \sqrt f}} 
\end{displaymath}
\vspace{.25in}
\item Very Different from the \\
 Conventional Wisdom\\
(e.g., Monte Carlo Generators)
\end{itemize}
\vfill\eject

\item \underline{Cosmic-Ray Evidence?}\\
Centauro Events:
\begin{itemize}
\item $n_{ch} \sim 100 $
\item $n_{\gamma} \sim 0$
\item CMS Energies $\geq 1 \, TeV$
\item Seen in Forward Direction\\
($\eta \sim 3.5-4.5$ for Fermilab)
\item Possibly Diffractive?
\item \underline{Relative} $p_{T}$ of Secondaries is Low\\
(Chiron Behavior)
\end{itemize}
	
JACEE Event:
\begin{itemize}
\item $n_{ch} \sim 18$
\item $n_{\gamma} \sim 60$
\item CMS Energy $> 200 \, GeV$
\item Chiron Behavior
\end{itemize}
\vfill\eject

\item \underline{T-864 Definition of DCC}\\
DCC $\equiv$ Cluster of Pions with:
\begin{itemize}
\item Neutral fraction $f$ (${{1}\over{2\sqrt f}}$ Distribution)
\item Near-Identical Momenta
\end{itemize}
In the DCC Rest Frame:
\begin{itemize}
\item $M_{DCC} = N_{\pi}<E_{\pi}>$
\item $<p_{\pi}^{2}>$ small ($\leq m_{\pi}^{2}$)
\end{itemize}

Look for DCC with Transverse Motion;\\
Important Parameters:
\begin{itemize}
\item Multiplicity Distribution $N_{\pi}$
\item Relative-Momentum Distribution $p_{\pi}^{2}$
\item Transverse-Velocity Distribution $V_{\perp}^{2}$
\item Pseudorapidity Distribution $\eta$
\end{itemize}




\end{enumerate}

\end{slide}{}