Development of highly granular calorimeters in CALICE

Abstract

The design of calorimeter systems for a detector at a future e + e − Linear Collider (ILC, CLIC) is largely driven by the requirements of jet reconstruction. The particle flow technique has been shown to be capable of achieving an energy resolution ∼ 30% / √ E, permitting the discrimination of W and Z bosons in their hadronic decays. Such performance requires the separation of neutral and charged energy deposits in the calorimeters, which in turn demands that they have high spatial granularity both transversely and longitudinally, and be placed within the magnet coil. The CALICE collaboration has been developing prototype calorimeters to meet these requirements. The electromagnetic calorimeter is based on tungsten absorbers and active layers of silicon pads of ∼ 5×5 mm 2 and/or crossed short scintillator strips of ∼ 5×45 mm 2 . The hadronic calorimeter could use iron or tungsten absorbers, sampled using either scintillator tiles of ∼ 3×3 cm 2 or gaseous detectors with ∼ 1×1 cm 2 readout. The scintillator option uses an analogue readout, while the gas detectors (RPCs, Micromegas or GEMs) use either digital (1 bit) or semi-digital (2 bit) readout. All these options are being pursued in CALICE. Key issues include: extreme compactness, hermeticity and scalability, power cycling and precise timing. We report on recent R&D and test beam activities from CALICE which address all these key questions.

New Physics requirements and technological challenges to be confronted by calorimeters in particle physics

“…• the second possibility is a combined design of the endcap calorimeters with tungsten plates and silicon detectors exploiting the so-called imaging calorimetry. These calorimeters were originally foreseen for the CALICE detector at the linear collider [17]. The high granularity of these detectors allows the shower development to be reconstructed inside the detector, separate overlapping showers as much as possible and link each energy deposit with a track in the tracker volume for charged particles.…”

Upgrade of the CMS Electromagnetic Calorimeter for High-Luminosity LHC Operation

“…The second solution is an imaging calorimeter, as proposed for the Calice experiment at the Linear Collider [12]. The principle is to measure the charged particle momenta in the silicon tracker, and neutral particles in the calorimeter.…”