Results from the commissioning of the ALICE Inner Tracking System with cosmics
Francesco Prino
备注：
4 pages, 1 figure with 3 panels (=3 separate eps files) To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennessee
The Inner Tracking System (ITS) is the detector of the ALICE central barrel located closest to the beam axis and it is therefore a key detector for tracking and vertexing performance. Here, the main results from the ITS commissioning with atmospheric muons in 2008 are presented, focusing in particular on the detector operation and calibration and on the methods developed for the alignment of the ITS detectors using reconstructed tracks.
大型离子对撞机实验（英语：Large Ion Collider Experiment，ALICE）是欧洲核子研究中心大型强子对撞机上的重离子实验。ALICE的主要跟踪装置是大容量TPC。TPC调试的里程碑以及当前的检测器校准的状态。在横向动量，位置以及在比能量损失（dE/dx）所获得的分辨率和噪声和电子漂移速度测量的结果进行了处理。
A Large Ion Collider Experiment (ALICE) is built to study the properties of the strongly interacting matter created in heavy-ion collisions at the LHC. With the upgrade of its Inner Tracking System (ITS), the ALICE experiment is going to increase the rate of data taking by almost two orders of magnitude. At the same time, the precision of secondary vertex reconstruction will become by at least a factor 3 better than it currently is. In this talk, we briefly show some selected physics results motivating the upgrade of the ITS, describe the design goals and the layout of the new detector, and hi…
During the second LHC long shutdown (LS2) the Inner Tracking System (ITS) of ALICE (A Large Ion Collider Experiment) will be replaced by seven layers of CMOS Monolithic Active Pixel Sensors (MAPS). The latest innovations in silicon imaging technology allow for the construction of large, ultra-thin silicon wafers which can further improve the capabilities of the ALICE tracker. The research and development studies towards the construction of a novel vertex detector have started. The detector installation has been proposed for the third LHC long shutdown (LS3) during which the three innermost lay…
The ALICE apparatus includes an Inner Tracking System for high-precision vertexing and tracking at midrapidity. Thanks to this detector, remarkable results were obtained with Run 2 data in all collision systems studied at the LHC. In this contribution, the role of the ITS in the event, track and secondary vertex reconstruction is highlighted, and the comparison of the resolution on the track impact parameter to the collision point in data and Monte Carlo simulations is reported. Finally, some of the main physics results obtained in pp and Pb--Pb collisions relying on the excellent ALICE vertex…
The ALICE Collaboration will undertake a major upgrade of the detector apparatus during the second LHC Long Shutdown LS2 (2019-2020) in view of the Runs 3 and 4 (2021-2029). The objective of the upgrade is two-fold: i) an improvement of the tracking precision and efficiency, in particular in the low-momentum range; ii) an improvement of the readout capabilities of the experiment, in order to fully exploit the luminosity for heavy ions envisaged after LS2. The first goal will be achieved by replacing the Inner Tracking System with a new tracker, composed of seven layers of silicon pixel detecto…
The ALICE Collaboration measures the production of low-mass dielectrons in pp, p-Pb and Pb-Pb collisions at the LHC. The main detectors used in the analyses are the Inner Tracking System, Time Projection Chamber and Time-Of-Flight detector, all located at mid-rapidity. The dielectron yield in p-Pb collisions shows an overall agreement with the hadronic cocktail. The pair transverse momentum distributions are sensitive to the contributions from open heavy-flavours. In Pb-Pb collisions, uncorrected background-subtracted yields have been extracted in two centrality classes. In pp collisions the p…
Photon-jet correlations are a promising channel for the study of parton energy loss in nuclear collisions. While existing measurements in pp and nuclear collisions have used high energy photons and jets, we focus on an unexplored kinematic range given by $12<p_{\mathrm{T}}<30$ GeV/$c$ photons and the corresponding low jet $p_{\mathrm{T}}$. We present results obtained using 5.02 TeV pp and p-Pb collisions. A combination of isolation and electromagnetic shower-shape variables is used to reduce the large background from meson decays and fragmentation photons. We show how the access to this kinema…
The excellent particle identification capabilities of the ALICE detector, using the time projection chamber and the time-of-flight detector, allow the detection of light nuclei and anti-nuclei. Furthermore, the high tracking resolution provided by the inner tracking system enables the separation of primary nuclei from those coming from the decay of heavier systems. This allows for the reconstruction of decays such as the hypertriton mesonic weak decay ($^3_Λ$H$\rightarrow ^3$He + $π^-$), the decay of a hypothetical bound state of a $Λ$n into a deuteron and pion or the H-dibaryon decaying into …
We present a new method for detection of multiply charmed baryons via their decays into strange baryons, using `strangeness tracking'. This method makes use of the state-of-the-art upgraded silicon detectors in ALICE during Runs 3, 4 and beyond will enable the novel possibility of tracking strange hadrons directly before they decay, leading to a very significant improvement in impact-parameter resolution. In this work, we will discuss how this new technique will be crucial to distinguish secondary strange baryons originating from charm decays from primary strange baryons. This is a particularl…
The Silicon Tracking System of the E16 experiment at J-PARC: construction, installation and commissioning in beam test experiments
GSI Helmholtzzentrum für Schwerionenforschung GmbH（GSI亥姆霍兹重离子研究中心）；Goethe University, Frankfurt am Main（法兰克福歌德大学）；Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK)（高能加速器研究机构粒子与核物理研究所）；Department of Physics, Kyoto University（京都大学物理系）；RIKEN Nishina Center for Accelerator-Based Science（理化学研究所仁科加速器科学中心）；Research Center for Nuclear Physics (RCNP), Osaka University（大阪大学核物理研究中心）；Advanced Science Research Center, Japan Atomic Energy Agency（日本原子能研究开发机构先进科学研究部）；AGH University of Krakow（克拉科夫AGH科技大学）
