STAR Spin related future detector upgrades

The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) has a rich spin physics program aimed at exploring the spin structure of the proton with polarized proton beams. In addition to the currently accessible channels, heavy flavor, charged vector boson production and forward mesons are integral parts of the long-term program. Such measurements require upgrades of the STAR tracking system and calorimetry. We are presenting an overview of the planned upgrades and the physics objectives driving them.Comment: 4 pages, 1 figure, to appear in the proceedings of the XIV International Workshop on Deep Inelastic Scattering (DIS2006), April 2006, Tsukuba, Japa

Higgs Physics at future Linear Colliders - A Case for precise Vertexing

The discovery of a Higgs boson by the experiments at the LHC marks a major breakthrough in particle physics, with far-reaching consequences for our understanding of the fundamental principles of our Universe. To fully explore this unique particle, experiments at high-energy electron-positron colliders are being planned, providing substantial added benefit over the capabilities of the LHC alone, such as model-independent measurements of couplings, constraints on invisible decays and precise measurements of the self-coupling. This contribution summarizes the Higgs physics program at such future facilities, highlighting in particular also the role of precise vertexing in achieving the ambitious goals of these experiments.Comment: 9 pages, 4 figures, to be published in the proceedings of the 22nd International Workshop on Vertex Detectors VERTEX 2013, Lake Starnberg, Germany, September 2013, v2 updated references. arXiv admin note: substantial text overlap with arXiv:1211.724

Calibration of a Highly Granular Hadronic Calorimeter with SiPM Readout

A highly granular hadronic calorimeter (HCAL) based on scintillator tiles with individual readout by silicon photomultipliers (SiPMs) has been constructed by the CALICE collaboration and has been tested extensively in particle beams at CERN. The 7608 SiPMs coupled to scintillator tiles in the approximately 1 cubic meter large calorimeter allow large sample studies of behavior of these devices under varying voltage and temperature as well as their saturation behavior. We also present detailed studies of the temperature dependence of the calorimeter signal in muon and hadron beams. The calibration of the full calorimeter using muons is discussed. In addition, a novel method for calibration and detector studies using minimum-ionizing track segments in hadronic showers, is explored.Comment: 4 pages, 9 figures, submitted to the Conference Record of the IEEE NSS 2008, Dresden, German

The Time Structure of Hadronic Showers in Imaging Calorimeters with Scintillator and RPC Readout

The intrinsic time structure of hadronic showers has been studied to evaluate its influence on the timing capability and on the required integration time of highly granular hadronic calorimeters in future collider experiments. The experiments have been carried with systems of 15 detector cells, using both scintillator tiles with SiPM readout and RPCs, read out with fast digitizers and deep buffers. These were installed behind the CALICE scintillator - Tungsten and RPC - Tungsten calorimeters as well as behind the CALICE semi-digital RPC - Steel calorimeter during test beam periods at the CERN SPS. We will discuss the technical aspects of these systems, and present results on the measurement of the time structure of hadronic showers in steel and tungsten calorimeters. These are compared to GEANT4 simulations, providing important information for the validation and the improvement of the physics models. In addition, a comparison of the observed time structure with scintillator and RPC active elements will be presented, which provides insight into the differences in sensitivity to certain aspects of hadronic showers depending on readout technology.Comment: 8 pages, 6 figures, proceedings for CHEF2013, Paris, France, April 201

Energy Reconstruction of Hadron Showers in the CALICE Calorimeters

The CALICE collaboration has constructed highly granular electromagnetic and hadronic calorimeter prototypes to evaluate technologies for the use in detector systems at the future International Linear Collider. These calorimeters have been tested extensively in particle beams at CERN and at Fermilab. We present analysis results for hadronic events recorded at CERN with a SiW ECAL, a scintillator tile HCAL and a scintillator strip tail catcher, the latter two with SiPM readout, focusing both on the HCAL alone and on the complete calorimeter setup. Particular emphasis is placed on the study of the linearity of the detector response and on the single particle energy resolution. The high granularity of the detectors was used to perform first studies of software compensation based on the local shower energy density, yielding significant improvements in the energy resolution. The required calibration precision to achieve this resolution, and the effect of calibration uncertainties, for the CALICE HCAL as well as for a complete hadron calorimeter at ILC, has been studied in detail. The prospects of using minimum-ionizing track segments within hadronic showers for calibration are also discussed.Comment: 4 pages, 6 figures, submitted to the conference record of the IEEE/NSS 2009, Orlando, Florida, USA, October 200

Studies of Scintillator Tiles with SiPM Readout for Imaging Calorimeters

Imaging hadronic calorimeters with scintillator readout use small scintillator tiles individually read out by silicon photomultipliers to achieve the necessary granularity needed for sophisticated reconstruction algorithms at future collider detectors. For a second generation prototype of the CALICE analog HCAL new, 3 mm thick scintillator tiles with an embedded wavelength shifting fiber and new photon sensor from CPTA are being fabricated. The availability of blue-sensitive SiPMs also allows fiberless coupling of the photon sensor to the tile, a technique requiring modified geometries to achieve a high degree of response uniformity. We discuss results from test bench and from test beam measurements of different scintillator tile geometries as well as prospects for fiberless coupling of photon sensors.Comment: 5 pages, 4 figures, to appear in the proceedings of the XIV International Conference on Calorimetry in High Energy Physics (CALOR 2010), Beijing, China, May 201

Operational Experience and First Results with a Highly Granular Tungsten Analog Hadron Calorimeter

Precision physics at future multi-TeV lepton colliders such as CLIC requires excellent jet energy resolution. The detectors need deep calorimeter systems to limit the energy leakage also for very highly energetic particles and jets. At the same time, compact physical dimensions are mandatory to permit the installation of the complete calorimeter system inside high-field solenoidal magnets. This requires very dense absorbers, making tungsten a natural choice for hadron calorimeters at such a future collider. To study the performance of such a calorimeter, a physics prototype with tungsten absorbers and scintillator tiles with SiPM readout as active elements has been constructed and has been tested in particle beams at CERN over a wide energy range from 1 GeV to 300 GeV. We report on the construction and on the operational experience obtained with muon, electron and hadron beams.Comment: To appear in the conference record of the IEEE Nuclear Science Symposium and Medical Imaging Conference, Valencia, Spain, October 201

Silicon Photomultipliers in Particle and Nuclear Physics

Following first large-scale applications in highly granular calorimeters and in neutrino detectors, Silicon Photomultipliers have seen a wide adoption in accelerator-based particle and nuclear physics experiments. Today, they are used for a wide range of different particle detector types, ranging from calorimeters and trackers to particle identification and veto detectors, large volume detectors for neutrino physics and timing systems. This article reviews the current state and expected evolution of these applications, highlighting strengths and limitation of SiPMs and the corresponding design choices in the respective contexts. General trends and adopted technical solutions in the applications are discussed.Comment: 17 pages, 18 figures, review paper published in Nuclear Instruments and Methods A; v2 correcting a missing figure link in tex