
\vspace{-5pt}
\subsection{The CLAS12 detector}
\vspace{-10pt}


%A brief overview of the CLAS12 detector is provided here.
% to provide context for the preliminary ASU results discussed in the next subsection.
While the CLAS12 detector is designed primarily to measure deeply exclusive scattering
using electron beams,
a forward tagger has been installed
within CLAS12 that enables quasi-real photon experiments with $q^2$ as low as 0.01 GeV$^2$.
The ASU efforts in Hall B make use of this forward tagger to perform
photoproduction measurements 
%for the $\Xi$ and $\Omega$ 
from
the cryogenic hydrogen target within the CLAS12 detector. 
%In addition to the presence of the forward tagger, 
%another key experimental consideration for using CLAS12 for our studies is that, at present,
%the particle identification for kaons should be better than that expected for
%the current configuration of 
%the GlueX detector in Hall D. 
%This superior particle identification for CLAS12 is the primary motivation for our
%use of that detector in the search for $\Omega^-$ and $\Xi$ baryons states.
%With the availability of both tagged photons and good kaon identification, 
%Hall B is well-suited for the measurements we propose to make. 

As seen in Fig. \ref{fig:clas12}, CLAS12
is composed of two main detector arrays: the Central Detector (CD) and the
Forward Detector (FD).
The FD covers the range of 5$^{\circ}$ to 40$^{\circ}$ in polar angle, whereas the CD
covers the polar angles from 40$^{\circ}$ to 135$^{\circ}$. 
The FD provides separation of identified
$K^{\pm}$ and $\pi^{\pm}$ having momenta less than 3 GeV/c, 
and separation of protons and $K^{\pm}$
with momenta less than 4.5 GeV/c.



\begin{wrapfigure}[]{R}{0.4\textwidth}
\vspace{-10pt}
\begin{center}
\includegraphics[width=\linewidth]{clas12-design.eps}
\end{center}
\vspace{-13pt}
\caption{Schematic diagram for CLAS12. The labeled subsystems
are described in the text. 
\newline
}
{\label{fig:clas12}}
\end{wrapfigure}


A cryogenic target cell is located at the center of the cylindrically-symmetric CD.
Surrounding  the cryogenic target cell
is a Silicon Vertex Tracker (SVT) yielding 1 mrad angular resolution in azimuthal angle
and 15 mrad in polar angle for charged tracks, as well as providing vertex resolution 
better than 2 mm.
Outside the SVT is the cylindrically-symmetric Central Time-of-Flight system (CTOF).
The CTOF scintillator array has a timing resolution of 50 ps.
The Central Electromagnetic Calorimeter forms the next cylindrical layer, consisting of
a scintillating-fiber/tungsten-powder array.
These detectors are housed within a 5-T superconducting solenoid
magnet of aperture 0.78 m. The original
CLAS superconducting toroidal magnet has been repurposed for CLAS12, with
the same six-sector azimuthal symmetry as the original detector.

Downstream of the SVT are the High Threshold Cherenkov Counters and the
Forward Tagger (FT) arrays.
Electrons that scatter with angles
between 2.5$^{\circ}$ and 4.5$^{\circ}$ are detected in the FT, 
enabling quasi-real photon experiments such as those we will undertake in this work. 
Beyond the FT are three regions
of drift chambers, forming  the Forward Tracking Chamber (FTC).
The chambers are arranged in a fashion similar to the original CLAS design, 
with Region 1 drift chambers located
before the torus magnet, Region 2 within the torus magnet, and Region 3 behind the torus.
Ultimately, the spatial resolution for this chamber package
is expected to be a factor of 3 better than the original CLAS system.
Downstream of the FTC are the Low Threshold Cherenkov Counters (LTCC),
which are modified versions
of the original CLAS Cherenkov counters with the same external geometry. 
As with the LTCC, the
Forward Time-of-Flight (FTOF) system has the same geometry as the original CLAS system,
but has been upgraded to obtain 80-ps timing resolution. The detector furthest downstream
is the Forward Electromagnetic Calorimeter, an array retained and repurposed
from the original CLAS detector.

