121106809
CHARACTER IDENTITIES IMPLIED BY SUPER-W3 INVARIANCE AND GENERALIZED COULOMB GAS DESCRIPTIONS
We study the super-W3, c=10/7 model and show that super-W3 invariance implies stringent constraints on the characters of the model. Taking into account these field identifications we can construct a Coulomb gas description of the model within the approach of Ref. 1. We suggest that Ref. 1 could be a general framework for constructing Coulomb gas descriptions for isolated solutions of W algebras not related to classical Lie algebras.
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.
209832724
Thermal operators in Ising percolation
We discuss a new cluster representation for the internal energy and the specific heat of the d -dimensional Ising model, obtained by studying the percolation mapping of an Ising model with an arbitrary set of antiferromagnetic links. Such a representation relates the thermal operators to the topological properties of the Fortuin-Kasteleyn (FK) clusters of Ising percolation and is a powerful tool to get new exact relations on the topological structure of FK clusters of the Ising model defined on an arbitrary graph.
204925001
Critical Boundary Conditions for the Effective String
Gauge systems in the confining phase induce constraints at the boundaries of the effective string, which rule out the ordinary bosonic string even with short distance modifications. Allowing topological excitations, corresponding to winding around the colour flux tube, produces at the quantum level a universal free fermion string with a boundary phase nu=1/4. This coincides with a model proposed some time ago in order to fit Monte Carlo data of 3D and 4D Lattice gauge systems better. A universal value of the thickness of the colour flux tube is predicted.
17987625
K-string tensions at finite temperature and integrable models
It has recently been pointed out that simple scaling properties of Polyakov correlation functions of gauge systems in the confining phase suggest that the ratios of k-string tensions in the low temperature region is constant up to terms of order T3. Here we argue that, at least in a three-dimensional 4 gauge model, the above ratios are constant in the whole confining phase. This result is obtained by combining numerical experiments with known exact results on the mass spectrum of an integrable two-dimensional spin model describing the infrared behaviour of the gauge system near the deconfining transition.
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.
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
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.
141117760
Assembly procedure of the ALICE silicon pixel detector module