Speaker
Summary
Dual readout calorimetry has so far focussed on the large fluctuations in the
electromagnetic content of hadronic showers (\fem) which degrade the performance in
several respects: poor energy resolution, a non-Gaussian response function, and a
non-linear response with increasing hadron energy. The next largest fluctuation is
the binding energy loss that is proportional to the MeV neutrons liberated in nuclear
break-up.
These liberated neutrons have velocities about $v \sim 0.05c$ and fill the volume of
the module like a gas. We expect to find the neutron signal in the long-time tails
of the plastic scintillating fibers which record the recoil protons in $np
\rightarrow np$ elastic scatters, through which the neutrons rapidly lose kinetic
energy as $\Delta E_n/E_n \approx 1/2$ per elastic scatter. The \dream collaboration
is seeking a means to attain the `ultimate' calorimeter energy resolution, and a
measurement of the neutron content shower-by-shower is one component of that goal.
