7393750
Green's functions in non-hermitian random matrix models☆
Abstract We review some recent techniques for dealing with non-hermitian random matrix models based on generalized Green's functions. We introduce the diagrammatic methods in the hermitian case and generalize them to the non-hermitian case. The results are illustrated in terms of the eigenvalue distribution, eigenvector statistics and addition laws.
123645613
Chiral Disorder and the QCD Dirac Spectrum
Using the Cell-Mann-Oakes-Renner (COR) relation together with semi-classical argu­ ments, we show that the bulk quark spectrum in QCD exhibits a variety of regimes includ­ ing the ergodic one described by random matrix theory. We suggest that a class of chiral transitions in QCD is of the metal-insulator type, universal spectral statistics at the critical point.
85537482
Rapidity and transverse momentum distributions of heavy quarks produced by double pomeron exchange
AbstractRapidity and transverse momentum distributions of heavy quarks produced by double exchange of Donnachie-Landshoff pomeron are presented and discussed. In the limit of small transverse momentum of the pair, the cross-section is almost independent of the sum ofq and
$$\bar q$$
 rapidities, but does depend on the rapidity difference and (rather strongly) on the transverse momenta of the produced quarks.
17701708
The Dijkgraaf-Vafa correspondence for theories with fundamental matter fields
In this talk I describe some applications of random matrix models to the study of N=1 supersymmetric Yang-Mills theories with matter fields in the fundamental representation. I review the derivation of the Veneziano-Yankielowicz-Taylor/Affleck-Dine-Seiberg superpotentials from constrained random matrix models (hep-th/0211082), a field theoretical justification of the logarithmic matter contribution to the Veneziano-Yankielowicz-Taylor superpotential (hep-th/0306242) and the random matrix based solution of the complete factorization problem of Seiberg-Witten curves for N=2 theories with fundamental matter (hep-th/0212212).
20516371
Characteristics of thermalization of boost-invariant plasma from holography.
We report on the approach toward the hydrodynamic regime of boost-invariant N=4 super Yang-Mills plasma at strong coupling starting from various far-from-equilibrium states at τ=0. The results are obtained through a numerical solution of Einstein's equations for the dual geometries, as described in detail in the companion article [M. P. Heller, R. A. Janik, and P. Witaszczyk, arXiv:1203.0755]. Despite the very rich far-from-equilibrium evolution, we find surprising regularities in the form of clear correlations between initial entropy and total produced entropy, as well as between initial entropy and the temperature at thermalization, understood as the transition to a hydrodynamic description. For 29 different initial conditions that we consider, hydrodynamics turns out to be definitely applicable for proper times larger than 0.7 in units of inverse temperature at thermalization. We observe a sizable anisotropy in the energy-momentum tensor at thermalization, which is nevertheless entirely due to hydrodynamic effects. This suggests that effective thermalization in heavy-ion collisions may occur significantly earlier than true thermalization.
118709171
Janus black holes
In this paper Janus black holes in A dS3 are considered. These are static solutions of an Einstein-scalar system with broken translation symmetry along the horizon. These solutions are dual to interface conformal field theories at finite temperature. An approximate solution is first constructed using perturbation theory around a planar BTZ blackhole. Numerical and exact solutions valid for all sets of parameters are then found and compared. Using the exact solution the thermodynamics of the system is analyzed. The entropy associated with the Janus black hole is calculated and it is found that the entropy of the black Janus is the sum of the undeformed black hole entropy and the entanglement entropy associated with the defect.
110170896
Development of a TPC detector for the ALICE experiment
Abstract A proportional chamber with ring cathode readout is foreseen for the ALICE Time Projection Chamber. It offers low gas gain operation, lightweight construction and good pulse shape. The Tape Automatic Bonding (TAB) process makes it possible to mount the VLSI analog front end electronics directly on the back face of the multilayer board carrying the ring cathode elements, yielding high channel density. At the same time, simulation work is done. Construction and first results will be presented.
123190188
TPC cathode read-out with C-pads
Abstract A Time Projection Chamber with “C” like shaped cathode pads was built and tested. It offers a low gas gain operation, a good pulse shape and a lightweight construction. The Pad Response Function (PRF), the cathode to anode pulse height ratios and the pad pulse shapes of the C-pad structure were measured and compared with planar cathode structures in two different wire geometries. The cathode to anode signal ratio was improved from between 0.2 and 0.4 up to 0.7. The PRF was considerably improved, it has a Gaussian shape and is narrower than in the case of the planar pads. The pulse shape from the C-pad read-out is similar to the pulse shape from a detector with a cylindrical shape of electrodes. A method for aluminum pad mass production based on a precise cold forging was developed and tested.
122123923
Time projection chambers for tracking and identification of radioactive beams
Time projection chambers (TPC) with delay-line readout have been built as position sensitive detectors for high-resolution experiments at the magnetic spectrometer FRS at GSI. The main qualities of TPCs are a small amount of material in the active area, a high tracking efficiency (≈98%), and a spatial resolution of σ∼115μm in x-direction, measured by a delay line, and σ∼50μm in y-direction, measured by drift time. The TPC works as a true two-dimensional detector. A multiple energy-loss measurement allows to identify light fragments (Z=4–6) with a resolution better then σZ<0.14. With the TPCs, several parameters of the spectrometer could be improved considerably and a higher momentum resolution of the FRS was obtained. The TPC construction, test results, and physical experiments are presented.
119975957
The new element 112
The new element 112 was produced and identified unambiguously in an experiment at SHIP, GSI Darmstadt. Two decay chains of the isotope277112 were observed in irradiations of208Pb targets with70Zn projectiles of 344 MeV kinetic energy. The isotope decays by emission of α particles with a half-life of (240−90+430)µs. Two different α energies of (11,649±20) keV and (11,454±20) keV were measured for the two observed decays. The cross-section measured in three weeks of irradiations is (1.0−0.4+1.8) pb.
15755675
First measurement of beta decay half-lives in neutron-rich Tl and Bi isotopes
Neutron-rich isotopes around lead, beyond N=126, have been studied exploiting the fragmentation of an uranium primary beam at the FRS-RISING setup at GSI. For the first time β-decay half-lives of 219 Bi and 211,212,213 Tl isotopes have been derived. The half-lives have been extracted using a numerical simulation developed for experiments in high-background conditions. Comparison with state of the art models used in r-process calculations is given, showing a systematic underestimation of the experimental values, at variance from close-lying nuclei.