A small prototype of a finely granulated digital hadron calorimeter with Resistive Plate Chambers as active elements was exposed to positive pions of 1 >. 16 GeV energy from the Fermilab test beam. The event selection separates events with mostly non-interacting particles and events with hadronic showers which initiated in the front part of the calorimeter. The data are compared to a Monte Carlo simulation of the set-up. The paper concludes with predictions for the performance of an extended digital hadron calorimeter.
The MAPS prototype of the proposed ALICE Forward Calorimeter (FoCal) is the highest granularity electromagnetic calorimeter, with 39 million pixels of $30 \times 30 μ$m$^{2}$. Particle showers can be studied with unprecedented detail with this prototype. Electromagnetic showers at energies between 2 GeV and 244 GeV have been studied and compared to Geant4 simulations. Simulation models can be tested in more detail than ever before and the differences observed between FoCal data and Geant4 simulations illustrates that improvements in electromagnetic models are still possible.
We investigate the effect of longitudinal and transverse calorimeter segmentation on event-by-event software compensation for hadronic showers. To factorize out sampling and electronics effects, events are simulated in which a single charged pion is shot at a homogenous lead glass calorimeter, split into longitudinal and transverse segments of varying size. As an approximation of an optimal reconstruction, a neural network-based energy regression is trained. The architecture is based on blocks of convolutional kernels customized for shower energy regression using local energy densities; biases…
Simulations of particle showers in calorimeters are computationally time-consuming, as they have to reproduce both energy depositions and their considerable fluctuations. A new approach to ultra-fast simulations are generative models where all calorimeter energy depositions are generated simultaneously. We use GEANT4 simulations of an electron beam impinging on a multi-layer electromagnetic calorimeter for adversarial training of a generator network and a critic network guided by the Wasserstein distance. The generator is constraint during the training such that the generated showers show the …
The highly granular calorimeter prototypes of the CALICE collaboration have provided large data samples with precise three-dimensional information on hadronic showers with steel and tungsten absorbers and silicon, scintillator and gas detector readout. From these data sets, detailed measurements of the spatial structure, including longitudinal and lateral shower profiles and of the shower substructure and time structure are extracted. Recent analyses have extended these studies to different particle species in calorimeters with scintillator readout and steel and tungsten absorbers, to energies…
The CALICE Semi-Digital Hadron Calorimeter technological prototype completed in 2011 is a sampling calorimeter using Glass Resistive Plate Chamber (GRPC) detectors as the active medium. This technology is one of the two options proposed for the hadron calorimeter of the International Large Detector for the International Linear Collider. The prototype was exposed in 2015 to beams of muons, electrons, and pions of different energies at the CERN Super Proton Synchrotron. The use of this technology for future experiments requires a reliable simulation of its response that can predict its performan…
The spatial resolution of laterally segmented electromagnetic calorimeters is studied on the basis of Monte-Carlo simulations worked-out for lead fluoride material. Parametrization of the relative resolution is proposed and optimized in terms of the energy of incoming particles and the elementary size of the calorimeter blocks. A new fit algorithm method is proposed that improves spatial resolution at high energies, and provides guidance for the design optimization of electromagnetic calorimeters.
National Energy Research Scientific Computing Center（国家能源研究科学计算中心）；Berkeley Lab（伯克利实验室）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；Berkeley Institute for Data Science（伯克利数据科学研究所）；University of California, Berkeley（加州大学伯克利分校）
Score-based generative models are a new class of generative algorithms that have been shown to produce realistic images even in high dimensional spaces, currently surpassing other state-of-the-art models for different benchmark categories and applications. In this work we introduce CaloScore, a score-based generative model for collider physics applied to calorimeter shower generation. Three different diffusion models are investigated using the Fast Calorimeter Simulation Challenge 2022 dataset. CaloScore is the first application of a score-based generative model in collider physics and is able…
Prototypes of electromagnetic and hadronic imaging calorimeters developed and operated by the CALICE collaboration provide an unprecedented wealth of highly granular data of hadronic showers for a variety of active sensor elements and different absorber materials. In this presentation, we discuss detailed measurements of the spatial and the time structure of hadronic showers to characterise the different stages of hadronic cascades in the calorimeters, which are then confronted with GEANT4-based simulations using different hadronic physics models. These studies also extend to the two different…
The high-luminosity upgrade of the LHC will come with unprecedented physics and computing challenges. One of these challenges is the accurate reconstruction of particles in events with up to 200 simultaneous proton-proton interactions. The planned CMS High Granularity Calorimeter offers fine spatial resolution for this purpose, with more than 6 million channels, but also poses unique challenges to reconstruction algorithms aiming to reconstruct individual particle showers. In this contribution, we propose an end-to-end machine-learning method that performs clustering, classification, and energ…
Calorimeter simulation is the most computationally expensive part of Monte Carlo generation of samples necessary for analysis of experimental data at the Large Hadron Collider (LHC). The High-Luminosity upgrade of the LHC would require an even larger amount of such samples. We present a technique based on Discrete Variational Autoencoders (DVAEs) to simulate particle showers in Electromagnetic Calorimeters. We discuss how this work paves the way towards exploration of quantum annealing processors as sampling devices for generation of simulated High Energy Physics datasets.
The precise measurement of photon or electron impact position is the prerequisite to reconstruct the origin of two photons events from decay of π0 and η mesons or the di-electron channel from quarkonia decay. To facilitate such a measurement, an electromagnetic calorimeter prototype using Monolithic Active Pixel Sensors (MAPS) was build and tested. The 30 $\times$ 30 m$^2$ granularity coupled with an optimized centre of gravity with power law weight method dedicatedly developed for the particle counting digital calorimeter, makes precise reconstruction of impact position of electromagnetic sho…
Layer 6 AI；University of Genoa（热那亚大学）；INFN（意大利国家核物理研究所）
Precision measurements and new physics searches at the Large Hadron Collider require efficient simulations of particle propagation and interactions within the detectors. The most computationally expensive simulations involve calorimeter showers. Advances in deep generative modelling - particularly in the realm of high-dimensional data - have opened the possibility of generating realistic calorimeter showers orders of magnitude more quickly than physics-based simulation. However, the high-dimensional representation of showers belies the relative simplicity and structure of the underlying physic…
University of California, Irvine（加州大学欧文分校）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）
Calorimeter shower simulations are often the bottleneck in simulation time for particle physics detectors. A lot of effort is currently spent on optimizing generative architectures for specific detector geometries, which generalize poorly. We develop a geometry-aware autoregressive model on a range of calorimeter geometries such that the model learns to adapt its energy deposition depending on the size and position of the cells. This is a key proof-of-concept step towards building a model that can generalize to new unseen calorimeter geometries with little to no additional training. Such a mod…
The granularity of calorimeter has been revolutionary boosted for future collider experiments. The calorimeter has been pushed to a stage that the sub structure of showers especially hadronic showers can be recorded to a high precision. New reconstruction algorithms are expected from these informations. Following the idea that shower follows the topology of the tree, we developed Arbor, a Particle Flow Algorithm framework. Tested on both simulated data and test beam data, it can successfully separate nearby showers. It has comparable jet energy resolution the best PFA algorithm for Internation…
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…
CaloScore v2: Single-shot Calorimeter Shower Simulation with Diffusion Models
National Energy Research Scientific Computing Center, Berkeley Lab（国家能源研究科学计算中心，伯克利实验室）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；Berkeley Institute for Data Science, University of California, Berkeley（加州大学伯克利分校伯克利数据科学研究所）
A novel hadron calorimeter is being developed for future lepton colliding beam detectors. The calorimeter is optimized for the application of Particle Flow Algorithms (PFAs) to the measurement of hadronic jets and features a very finely segmented readout with 1 x 1 cm2 cells. The active media of the calorimeter are Resistive Plate Chambers (RPCs) with a digital, i.e. one-bit, readout. To first order the energy of incident particles in this calorimeter is reconstructed as being proportional to the number of pads with a signal over a given threshold. A large-scale prototype calorimeter with appr…
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…
A novel hadron calorimeter is being developed for future lepton colliding beam detectors. The calorimeter is optimized for the application of Particle Flow Algorithms (PFAs) to the measurement of hadronic jets and features a very finely segmented readout with 1 x 1 cm2 cells. The active media of the calorimeter are Resistive Plate Chambers (RPCs) with a digital, i.e. one-bit, readout. To first order the energy of incident particles in this calorimeter is reconstructed as being proportional to the number of pads with a signal over a given threshold. A large-scale prototype calorimeter with appr…
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…
