141117760
Assembly procedure of the ALICE silicon pixel detector module
122908768
The Alice silicon pixel detector
CERN European Organization for Nuclear Research, CH-1211 Geneva 23, Switzerland Universita degli Studi di Padova, I-35131, Padova, Italy Dipartimento IA di Fisica e Sez. INFN di Bari, I-70126,Bari,Italy Comenius University, SK-84215 Bratislava, Slovakia NIKHEF, National Institute for Nuclear Physics and High Energy Physics, 1098 SJ Amsterdam, The Netherlands Slovak Academy of Sciences, SK-04353, Kosice, Slovakia Universita di Roma I, La Sapienza, I-00185, Roma, Italy
110392152
LEPIX: MONOLITHIC DETECTORS FOR PARTICLE TRACKING IN STANDARD VERY DEEP SUBMICRON CMOS TECHNOLOGIES
A few silicon foundries offer the possibility of porting standard deep-submicron CMOS processes on wafers with resistivity well above 100 Ω·cm. In this paper we propose to use this option to implement monolithic sensors for particle tracking that combine the low power consumption and material budget offered by monolithic active pixel sensors (MAPS) with the speed and radiation hardness characterizing hybrid pixel detectors. Our simulations suggest that a uniform depletion layer with a thickness of at least 40 μm should be obtained by applying a reverse bias voltage of 100 V. The charge collection is fully dominated by drift, which is a key factor to guarantee adequate resistance against radiation-induced bulk damage. The paper describes the sensor concept and the key issues involved in the design of the associated read-out electronics.
109039717
Test beam performance of the ALICE silicon pixel detector
Abstract The ALICE Silicon Pixel Detector (SPD) will include 1200 bump-bonded readout chips produced in a commercial 0.25 μ CMOS process. Each chip has 8192 pixels of size 50 × 425 μ m 2 , which leads to about 10 million readout channels in the whole detector system. Test beam measurements were recently carried out at the CERN SPS using a positive proton/pion beam as well as a 158 A GeV/c heavy ion beam (In) with a fixed Pb target. Analysis show good performance of the ALICE chip and assemblies in the positive beam as well as in the high multiplicity In beam. Preliminary results from data analysis show good performance of the SPD and fulfill the ALICE requirements.
53308940
The ALICE silicon pixel detector readout electronics
Abstract The ALICE silicon pixel detector (SPD) constitutes the two innermost layers of the ALICE inner tracking system (ALICE Collaboration, 1999) [1] . The SPD is built with 120 detector modules (half-staves) and contains about 10 million pixels in total. The half-staves are connected to the off-detector electronics, housed in a control room 100 m away, via bidirectional optical links. The stream of data from the front-end electronics is processed in 20 VME readout modules, called routers, based on FPGAs. Three 2-channel link-receiver daughter cards, also based on FPGAs, are plugged in each router. Each link-receiver card receives data via the optical link from two half-staves, applies the zero suppression and passes them to the router to be processed and sent to the ALICE–DAQ system through the detector data link (DDL). The SPD control, configuration and data monitoring are performed using the VME interface embedded in the router.
111275354
Assembly procedure of the module (half-stave) of the ALICE Silicon Pixel Detector
The Silicon Pixel Detector (SPD) forms the two innermost layers of the ALICE Inner Tracking System (ITS). The detector includes 1200 readout ASICs, each containing 8192 pixel cells, bump-bonded to Si sensor elements. The thickness of the readout chip and the sensor element is 150 μm and 200 μm, respectively. Low-mass solutions are implemented for the bus and the mechanical support. In this contribution, we describe the basic module (half-stave) of the two SPD layers and we give an overview of its assembly procedure.
17086715
Finite temperature corrections in 2d integrable models
Abstract We study the finite size corrections for the magnetization and the internal energy of the 2d Ising model in a magnetic field by using transfer matrix techniques. We compare these corrections with the functional form recently proposed by Delfino and LeClair–Mussardo for the finite temperature behaviour of one-point functions in integrable 2d quantum field theories. We find a perfect agreement between theoretical expectations and numerical results. Assuming the proposed functional form as an input in our analysis we obtain a relevant improvement in the precision of the continuum limit estimates of both quantities.
10634649
The Kazakov-Migdal model as a high temperature lattice gauge theory
Abstract We show that the Kazakov-Migdal (KM) induced gauge model d dimensions describes the high temperature limit of ordinary lattice gauge theories in d +1 dimensions. The matter fields are related to the Polyakov loops, while the spatial gauge variables become the gauge fields of the KM model. This interpretation of the KM model is in agreement with some recent results in high temperature lattice QCD.
18110840
Universal behaviour of interfaces in 2d and dimensional reduction of Nambu-Goto strings
Abstract We propose a simple effective model for the description of interfaces in 2d statistical models, based on the first-order treatment of an action corresponding to the length of the interface. The universal prediction of this model for the interface free energy agrees with the result of an exact calculation in the case of the 2d Ising model. This model appears as a dimensional reduction of the Nambu–Goto stringy description of interfaces in 3d, i.e., of the capillary wave model.
15775859
Recent progress in the effective string theory description of LGTs
In presence of a static pair of sources, the spectrum of low-lying states of any confining gauge theory in D space-time dimensions is described, at large source separations, by an effective string theory. Recently two important advances improved our understanding of this effective theory. First, it was realized that the form of the effective action is strongly constrained by the requirement of the Lorentz invariance of the gauge theory, which is spontaneously broken by the formation of a long confining flux tube in the vacuum. This constraint is strong enough to fix uniquely the first few subleading terms of the action. Second, it has been realized that the first of these allowed terms - a quartic polynomial in the field derivatives - is exactly the composite field $T\bar{T}$, built with the chiral components, $T$ and $\bar{T}$, of the energy-momentum tensor of the 2d QFT describing the infrared limit of the effective string. This irrelevant perturbation is quantum integrable and yields, through the thermodynamic Bethe Ansatz (TBA), the energy levels of the string which exactly coincide with the Nambu-Goto spectrum. In this talk we first review the general implications of these two results and then, as a test of the power of these methods, use them to construct the first few boundary corrections to the effective string action.