
\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}{0.6\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.

