Thursday, September 27, 2018, 16:00
OSGA/EG06
David Barney, CERN
Abstract:
Calorimetry in high-energy physics is rapidly evolving, with new
specifications (e.g. higher energies, enormous particle densities) and a
wide variety of technologies being employed, both for signal creation
and detection. Advances in large-area highly-segmented detectors based
on, for example, silicon and scintillators, are providing possibilities
for high-granularity calorimetry, providing unprecedented levels of
information from particle showers. This talk focuses on one example of
high-granularity calorimetry: The CMS HGCAL, being designed to replace
the existing endcap calorimeters for the HL-LHC era. It is a sampling
calorimeter, featuring unprecedented transverse and longitudinal readout
segmentation for both electromagnetic (CE-E) and hadronic (CE-H)
compartments. This will facilitate particle-flow calorimetry, where the
fine structure of showers can be measured and used to enhance pileup
rejection and particle identification, whilst still achieving good
energy resolution. The CE-E and a large fraction of CE-H will use
silicon as active detector material: the sensors will be of hexagonal
shape, maximizing the available 8-inch circular wafer area. The
lower-radiation environment will be instrumented with scintillator tiles
with on-tile SiPM readout. This concept borrows heavily from designs
produced by the CALICE collaboration
- calorimetry for CLIC and ILC etc. - but the challenges of such a
detector at a hadron collider are considerably larger than at the ILC.
In addition to the hardware aspects, the reconstruction of signals -
both online for triggering and offline - is a quantum leap from existing
detectors. We present the reasoning and ideas behind the HGCAL, its
current status including design and expected performance, and the
challenges ahead.