One of the most important requirements for a detector at the ILC is good jet energy resolution. It is widely believed that the particle flow approach to calorimetry is the key to achieving the goal of 0.3/sqrt(E[GeV]). This paper describes the current performance of the PandoraPFA particle flow algorithm. For 45 GeV jets in the Tesla TDR detector concept, the ILC jet energy resolution goal is reached. At higher energies the jet energy resolution becomes worse and can be described by the empirical expression: sigma_E/E ~ 0.265/sqrt(E[GeV]) + 1.2x10^{-4}E[GeV].
The CALICE Collaboration is carrying out research and development into calorimetry for a detector at the International Linear Collider (ILC). CALICE is investigating a range of technologies for both electromagnetic and hadronic calorimetry. An overview of the prototypes and selected test-beam results are presented.
The Particle Flow (PFlow) approach to calorimetry promises to deliver unprecedented jet energy resolution for experiments at future high energy colliders such as the proposed International Linear Collider (ILC). This paper describes the PandoraPFA particle flow algorithm which is then used to perform the first systematic study of the potential of high granularity PFlow calorimetry. For simulated events in the ILD detector concept, a jet energy resolution of sigma_E/E < 3.8 % is achieved for 40-400 GeV jets. This result, which demonstrates that high granularity PFlow calorimetry can meet the ch…
Detectors proposed for the International Linear Collider (ILC) incorporate a tungsten sampling calorimeter (`BeamCal') intended to reconstruct showers of electrons, positrons and photons that emerge from the interaction point of the collider with angles between 5 and 50 milliradians. For the innermost radius of this calorimeter, radiation doses at shower-max are expected to reach 100 MRad per year, primarily due to minimum-ionizing electrons and positrons that arise in the induced electromagnetic showers of e+e- `beamstrahlung' pairs produced in the ILC beam-beam interaction. However, radiatio…
Detectors proposed for the International Linear Collider (ILC) incorporate a tungsten sampling calorimeter (`BeamCal') intended to reconstruct showers of electrons, positrons and photons that emerge from the interaction point of the collider with angles between 5 and 50 milliradians. For the innermost radius of this calorimeter, radiation doses at shower-max are expected to reach 100 MRad per year, primarily due to minimum-ionizing electrons and positrons that arise in the induced electromagnetic showers of e+e- `beamstrahlung' pairs produced in the ILC beam-beam interaction. However, radiatio…
One of the most important requirements for a detector at the ILC is good jet energy resolution. It is widely believed that the particle flow approach to calorimetry is the key to achieving the ILC goal of a di-jet invariant mass resolution sigma_m/m < Gamma_Z/m_Z. This paper describes the current performance of the PandoraPFA particle flow algorithm. For simulated light quark jets in the Tesla TDR detector, the jet energy resolution achieved is better than sigma_E/E ~ 3.4% for jet energies in the range 45-250 GeV. This represents the first demonstration that Particle Flow Calorimetry can reach…
Detectors proposed for the International Linear Collider (ILC) incorporate a tungsten sampling calorimeter (`BeamCal') intended to reconstruct showers of electrons, positrons and photons that emerge from the interaction point of the collider with angles between 5 and 50 milliradians. For the innermost radius of this calorimeter, radiation doses at shower max are expected to reach 100 Mrad per year, primarily due to minimum-ionizing electrons and positrons that arise in the induced electromagnetic showers of e$^+$e$^-$ `beamstrahlung' pairs produced in the ILC beam-beam interaction. However, ra…
Detectors proposed for the International Linear Collider (ILC) incorporate a tungsten sampling calorimeter (`BeamCal') intended to reconstruct showers of electrons, positrons and photons that emerge from the interaction point of the collider with angles between 5 and 50 milliradians. For the innermost radius of this calorimeter, radiation doses at shower max are expected to reach 100 Mrad per year, primarily due to minimum-ionizing electrons and positrons that arise in the induced electromagnetic showers of e+e- `beamstrahlung' pairs produced in the ILC beam-beam interaction. However, radiatio…
The motivation for PF calorimetry is to experimentally measure the energy of hadron jets with excellent resolution. In particle flow designs, sigma(E)/E < 5% should be possible for a range of jet energies from 50 GeV to 250 GeV, important particularly for experiments at electron-positron colliders (ILC, CLIC, FCCee, CEPC). The high granularity, which is essential for PF calorimetry, can also be very beneficial for removal of background from pile-up on an event-by-event basis making such calorimeters an attractive approach for hadron collider experiments, for example the HGCAL under constructio…
Glass RPC detectors are an attractive candidate for the active part of a highly granular digital hadron calorimeter (DHCAL) at the ILC. A numerical study, based on the GEANT3 simulation package, of the performance of such a calorimeter is presented in this work. A simplified model for the RPC response, tuned on real data, is implemented in the simulation. The reliability of the simulation is demonstrated by comparison to existing data collected with a large volume calorimeter prototype exposed to a pion beam in an energy range from 2 GeV to 10 GeV. In view of an optimization of the readout pit…
To evaluate different technologies for calorimetry at the International Linear Collider, the CALICE collaboration has constructed a highly granular analog hadron calorimeter with small scintillator cells, individually read out by silicon photomultipliers. This device has been extensively tested in particle beams. A digital hadron calorimeter based on RPC readout is currently under construction, with first prototype beam test results already available. The high granularity allows detailed investigations of the substructure of hadronic showers, and can also be exploited for the development of so…
A high-energy e+e- collider, such as the ILC or CLIC, is arguably the best option to complement and extend the LHC physics programme. A lepton collider will allow for exploration of Standard Model Physics, such as precise measurements of the Higgs, top and gauge sectors, in addition to enabling a multitude of New Physics searches. However, physics analyses at such a collider will place unprecedented demands on calorimetry, with a required jet energy resolution of σ(E)/E < 3.5%. To meet these requirements will need a new approach to calorimetry. The particle flow approach to calorimetry require…
This talk reviews the development of imaging calorimeters for the purpose of applying Particle Flow Algorithms (PFAs) to the measurement of hadronic jets at a future lepton collider. After a short introduction, the current status of PFA developments is presented, followed by a review of the major developments in electromagnetic and hadronic calorimetry.
This paper will argue for continued effort in developing imaging calorimeters for future colliders and/or upgrades to existing detectors. Imaging calorimeters offer a plethora of advantages beyond their application in conjunction with Particle Flow Algorithms. Further R&D is needed to turn the first generation prototypes into viable detectors for colliding beam experiments.
The 2022 Snowmass Community Summer Study consisted of two years of engagement with the particle physics community to craft a US particle physics strategy for the next decade, culminating in the 2022 Snowmass Book. This Report of the Topical Group on Calorimetry forms the basis for a small section of the Snowmass Book dealing with the community's vision for calorimetry going forward. It is the distillation of ideas put forth in public meetings and numerous white papers already freely available. The Report describes particle flow and dual readout approaches, integration of precision timing, and …
The particle flow approach to calorimetry can provide unprecedented jet energy resolution at a future high energy collider, such as the International Linear Collider (ILC). However, the use of particle flow calorimetry at the proposed multi-TeV Compact Linear Collider (CLIC) poses a number of significant new challenges. At higher jet energies, detector occupancies increase, and it becomes increasingly difficult to resolve energy deposits from individual particles. The experimental conditions at CLIC are also significantly more challenging than those at previous electron-positron colliders, wit…
Precision physics at future colliders requires highly granular calorimeters to support the Particle Flow Approach for event reconstruction. This article presents a review of about 10 - 15 years of R\&D, mainly conducted within the CALICE collaboration, for this novel type of detector. The performance of large scale prototypes in beam tests validate the technical concept of particle flow calorimeters. The comparison of test beam data with simulation, of e.g.\ hadronic showers, supports full detector studies and gives deeper insight into the structure of hadronic cascades than was possible previ…
The hadronic cascade description developed in an earlier paper is extended to the response of an idealized fine-sampling hadron calorimeter. Calorimeter response is largely determined by the transfer of energy $E_e$ from the hadronic to the electromagnetic sector via $π^0$ production. Fluctuations in this quantity produce the "constant term" in hadron calorimeter resolution. The increase of its fractional mean, $f_{\rm em}^0 = \vev{E_e}/E$, with increasing incident energy $E$ causes the energy dependence of the $π/e$ ratio in a noncompensating calorimeter. The mean hadronic energy fraction, $f…
The current developments for future electron-positron colliders are driven by the Particle Flow concept. In these developments, high granularity calorimeters play a central role. This presentation will focus on a new Particle Flow Algorithm (PFA) developed for high granularity calorimeters, and especially for the Semi-Digital Hadronic CALorimeter (SDHCAL) option of the International Large Detector (ILD) project. The first PFA for ILD was PandoraPFA. This new PFA (APRIL) is based on the PandoraPFA Software Development Kit, but implements a different clustering inspired from the ARBOR PFA approa…
The CALICE collaboration conducts calorimeter R&D for highly granular calorimeters, mainly for their application in detectors for a future lepton collider at the TeV scale. The activities ranges from generic R&D with small devices up to extensive beam tests with prototypes comprising up to several 100000 calorimeter cells. CALICE has validated the performance of particle flow algorithms with test beam data and delivers the proof of principle that highly granular calorimeters can be built, operated and understood. The successes achieved in the past years allows the step from prototypes to calor…
A high momentum resolution is required for the precision measurement of Higgs boson at the International Linear Collider (ILC) using the recoil mass technique. The International Large Detector (ILD) is designed to meet this requirement by an MPGD-readout Time Projection Chamber (TPC) providing about 200 sample points each with a spatial resolution of 100 $μ$m operated in a magnetic field of 3.5 T. However, there is a potential problem that many positive ions generated in the gas amplification process in the end-plane detector modules would flow back into the drift volume of the TPC and distort…
In this White Paper for the 2021 Snowmass process, we detail the status and prospects for dual-readout calorimetry. While all calorimeters allow estimation of energy depositions in their active material, dual-readout calorimeters aim to provide additional information on the light produced in the sensitive media via, for example, wavelength and polarization, and/or a precision timing measurements, allowing an estimation of the shower-by-shower particle content. Utilizing this knowledge of the shower particle content may allow unprecedented energy resolution for hadronic particles and jets and n…
The Compact Linear Collider CLIC is designed to deliver e+e- collisions at a center of mass energy of up to 3 TeV. The detector systems at this collider have to provide highly efficient tracking and excellent jet energy resolution and hermeticity for multi-TeV final states with multiple jets and leptons. In addition, the detector systems have to be capable of distinguishing physics events from large beam-induced background at a crossing frequency of 2 GHz. Like for the detector concepts at the ILC, CLIC detectors are based on event reconstruction using particle flow algorithms. The two detecto…
The International Large Detector, ILD, is a detector concept which has been developed for the electron-positron collider ILC. The detector has been optimized for precision physics in a range of energies between 90 GeV and 1 TeV. ILD features a high precision, large volume combined silicon and gaseous tracking system, together with a high granularity calorimeter, all inside a 3.5 T solenoidal magnetic field. The paradigm of particle flow has been the guiding principle of the design of ILD. In this document the required performance of the detector, the proposed implementation and the readiness o…
With centre-of-mass energies covering the Z pole, the WW threshold, the HZ production, and the top-pair threshold, the FCC-ee offers unprecedented possibilities to measure the properties of the four heaviest particles of the Standard Model (the Higgs, Z, and W bosons, and the top quark), and also those of the b and c quarks and of the $τ$ lepton. At these moderate energies, the role of the calorimeters is to complement the tracking systems in an optimal (a.k.a. particle-flow) event reconstruction. In this context, precision measurements and searches for new particles can fully profit from the …
The particle detectors at the future linear colliders, like ILD and SiD, use Particle Flow Algorithms (PFA)s to reach higher jet energy resolutions than the classical pure calorimetry. During the past few years, the University of Iowa group developed the Iowa PFA. This algorithm has been used to benchmark the performance of the SiD detector for the Letter Of Intent of 2009. Recently, new strategies and techniques are included in the different parts of this algorithm in order to increase its performance. The latest improvements and results of the Iowa PFA will be discussed.
One of the most important aspects of detector development for the ILC is a good jet energy resolution sigma_E/E. To achieve the goal of high precision measurements sigma_E/E = 0.30/sqrt(E(GeV)} is proposed. The particle flow approach together with highly granular calorimeters is able to reach this goal. This paper presents a new particle flow algorithm, called Track-Based particle flow, and shows first performance results for 45 GeV jets based on full detector simulation of the Tesla TDR detector model.
One of the potential problems of a Micro-Pattern Gaseous Detector (MPGD)-based Time Projection Chamber (TPC) is the Ion back Flow (IBF): ions generated through the avalanche amplification process flow back to the drift volume of the TPC and disarrange an electric field inside it. Consequently non-negligible degradation of azimuthal spatial resolution is caused due to this IBF. Meanwhile, it is necessary to collect primary ionized electrons to maintain intrinsic performance of the MPGDs. The MPGD based TPC is currently planned to be used as a central tracking detector of the International Large…
The studies presented in this paper provide a first experimental test of the Particle Flow Algorithm (PFA) concept using data recorded in high granularity calorimeters. Pairs of overlaid pion showers from CALICE 2007 test beam data are reconstructed by the PandoraPFA program developed to implement PFA for a future lepton collider. Recovery of a neutral hadron's energy in the vicinity of a charged hadron is studied. The impact of the two overlapping hadron showers on energy resolution is investigated. The dependence of the confusion error on the distance between a 10 GeV neutral hadron and a ch…
The physics program of future lepton colliders such as the ILC, will benefit from a jet energy resolution in the range 3-4%. The International Large Detector (ILD) reaches this goal over a large range of jet energies. In this paper, we report on the dependence of the simulated ILD performance on various parameters of its silicon-tungsten ECAL. We investigate the effects of dead areas in the silicon sensors, the thickness of the PCB at the heart of the detector, and the robustness of its performance with respect to dead channels, noise, mis-calibration and cross-talk.
The particle flow approach to calorimetry benefits from highly granular calorimeters and sophisticated software algorithms in order to reconstruct and identify individual particles in complex event topologies. The high spatial granularity, together with analogue energy information, can be further exploited in software compensation. In this approach, the local energy density is used to discriminate electromagnetic and purely hadronic sub-showers within hadron showers in the detector to improve the energy resolution for single particles by correcting for the intrinsic non-compensation of the cal…
Calorimetry at future linear colliders could be based on a particle flow approach where granularity is the key to high jet energy resolution. Among different technologies, Micromegas chambers with 1 cm2 pad segmentation are studied for the active medium of a hadronic calorimeter. A chamber of 1 m2 with 9216 channels read out by a low noise front-end ASIC called MICROROC has recently been constructed and tested. Chamber design, ASIC circuitry and preliminary test beam results are reported.
The basic prototype of a tile hadron calorimeter (HCAL) for the International Linear Collider (ILC) has been realised and extensively tested. A major aspect of the proposed concept is the improvement of the jet energy resolution by measuring details of the shower development and combining them with the data of the tracking system (particle flow). The prototype utilises scintillating tiles that are read out by novel Silicon Photomultipliers (SiPMs) and takes into account all design aspects that are demanded by the intended operation at the ILC. Currently, a new 12 layer prototype with about 340…
Conceptual Design of a Novel Highly Granular Crystal Electromagnetic Calorimeter for Future Higgs Factories
Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；State Key Laboratory of Particle Detection and Electronics（粒子探测与电子学国家重点实验室）；University of Chinese Academy of Sciences（中国科学院大学）；China Center of Advanced Science and Technology（中国高等科学技术中心）；Institute of Nuclear and Particle Physics, School of Physics and Astronomy, Shanghai Jiao Tong University（上海交通大学物理与天文学院核物理与粒子物理研究所）；Tsung-Dao Lee Institute, Shanghai Jiao Tong University（上海交通大学李政道研究所）；National Key Laboratory of Dark Matter Physics, Shanghai Key Laboratory for Particle Physics and Cosmology, Key Laboratory for Particle Astrophysics and Cosmology (MoE)（暗物质物理全国重点实验室、粒子物理与宇宙学上海市重点实验室、粒子天体物理 cosmology 教育部重点实验室）
