119245590
Correlation functions of three heavy operators — the AdS contribution
A bstractWe consider operators in $ \mathcal{N} = {4} $ SYM theory which are dual, at strong coupling, to classical strings rotating in S5. Three point correlation functions of such operators factorize into a universal contribution coming from the AdS part of the string sigma model and a state-dependent S5 contribution. Consequently a similar factorization arises for the OPE coefficients. In this paper we evaluate the AdS universal factor of the OPE coefficients which is explicitly expressed just in terms of the anomalous dimensions of the three operators.
119063881
New Results on the Odderon in QCD
We present our recent results on the odderon intercept in perturbative QCD, obtained through the solution of the Baxter equation and investigation of the spectrum of the relevant constant of motion.
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.
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.
11654094
The decay of quantum D-branes
Abstract We study the quantum decay of D0-branes in two-dimensional 0B string theory. The quantum nature of the branes provides a natural cut-off for the closed string emission rate. We find exact quantum mechanical wave functions for the decaying branes and show how one can include the effects of the Fermi sea for any string coupling (Fermi energy).
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.
55827740
GEM-TPC TRACKERS FOR THE SUPER-FRS AT FAIR
For the slow extraction part of the beam diagnostics system of the Superconducting Projectile Fragment Separator (Super-FRS) of FAIR-facility a total of 32 detectors are needed. They will be used for beam monitoring, tracking and characterization of the produced ions. GEM-TPC detectors can perform over wide dynamic range without disturbing the beam and are thus suitable for this kind of in-beam detection. We present the simulations and first measurements with the GEMs of the Super-FRS GEM-TPC prototype.
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.
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.
120334493
Time Projection Chambers with C-pads for heavy ion tracking
Time Projection Chambers with C-pads and integrated delay line readout were developed as position sensitive detectors for the Fragment separator at GSI Darmstadt. The main advantages of TPCs are a small amount of matter in the sensitive volume, high spatial resolution, and high tracking efficiency. Working parameters in experimental conditions are presented. Internal spatial resolutions of σ x = 88 μ m and σ y = 38 μ m were achieved. The tracking efficiency dependence on ion beam intensity was studied with 238 U beam at 1  GeV/ u energy. Efficiency of more than 99% was achieved up to 40 kHz and over 90% for 250 kHz 238 U beam intensity. Different kinds of ions from proton to uranium were measured in many experiments and confirmed the result obtained.
19937921
Exploring the anomaly in the interaction cross section and matter radius of 23O
New measurements of the interaction cross sections of 22,23O at 900A MeV performed at the GSI, Darmstadt are reported that address the unsolved puzzle of the large cross section previously observed for 23O. The matter radii for these oxygen isotopes extracted through a Glauber model analysis are in good agreement with the new predictions of the ab initio coupled-cluster theory reported here. They are consistent with a 22O+neutron description of 23O as well.