Radion Assisted Gauge Inflation

We propose an extension to the recently proposed extranatural or gauge inflation scenario in which the radius modulus field around which the Wilson loop is wrapped assists inflation as it shrinks. We discuss how this might lead to more generic initial conditions for inflation.Comment: 10 pages, 2 figure

Large N(c′)_(c'), chiral approach to M(n′)_(n') at finite temperature

We study the temperature dependence of the eta and eta[prime] meson masses within the framework of U(3)L×U(3)R chiral perturbation theory, up to next-to-leading order in a simultaneous expansion in momenta, quark masses and number of colors. We find that both masses decrease at low temperatures, but only very slightly. We analyze higher order corrections and argue that large Nc suggests a discontinuous drop of Meta[prime] at the critical temperature of deconfinement Tc, consistent with a first order transition to a phase with approximate U(1)A symmetry

Anomalous amplitudes in a thermal bath

I review the implications of the axial anomaly in a thermal bath. I assume that the Adler-Bardeen theorem applies at nonzero temperature, so that the divergence of the axial current remains is independent of temperature. Nevertheless, I argue that while the anomaly doesn't change with temperature, ``anomalous'' mesonic couplings do. This is verified by explicit calculations in a low temperature expansion, and near the chiral phase transition.Comment: 11 pages, PTPTeX, to appear in the Proceedings of YKIS '9

The Upgrade of the CMS RPC System during the First LHC Long Shutdown

The CMS muon system includes in both the barrel and endcap region Resistive Plate Chambers (RPC). They mainly serve as trigger detectors and also improve the reconstruction of muon parameters. Over the years, the instantaneous luminosity of the Large Hadron Collider gradually increases. During the LHC Phase 1 (~first 10 years of operation) an ultimate luminosity is expected above its design value of 10^34/cm^2/s at 14 TeV. To prepare the machine and also the experiments for this, two long shutdown periods are scheduled for 2013-2014 and 2018-2019. The CMS Collaboration is planning several detector upgrades during these long shutdowns. In particular, the muon detection system should be able to maintain a low-pT threshold for an efficient Level-1 Muon Trigger at high particle rates. One of the measures to ensure this, is to extend the present RPC system with the addition of a 4th layer in both endcap regions. During the first long shutdown, these two new stations will be equipped in the region |eta|<1.6 with 144 High Pressure Laminate (HPL) double-gap RPCs operating in avalanche mode, with a similar design as the existing CMS endcap chambers. Here, we present the upgrade plans for the CMS RPC system for the fist long shutdown, including trigger simulation studies for the extended system, and details on the new HPL production, the chamber assembly and the quality control procedures.Comment: 9 pages, 6 figures, presented by M.Tytgat at the XI workshop on Resistive Plate Chambers and Related Detectors (RPC2012), INFN - Laboratori Nazionali di Frascati, February 5-10, 201

Background reionization history from omniscopes

The measurements of the 21-cm brightness temperature fluctuations from the neutral hydrogen at the Epoch of Reionization (EoR) should inaugurate the next generation of cosmological observables. In this respect, many works have concentrated on the disambiguation of the cosmological signals from the dominant reionization foregrounds. However, even after perfect foregrounds removal, our ignorance on the background reionization history can significantly affect the cosmological parameter estimation. In particular, the interdependence between the hydrogen ionized fraction, the baryon density and the optical depth to the redshift of observation induce nontrivial degeneracies between the cosmological parameters that have not been considered so far. Using a simple, but consistent reionization model, we revisit their expected constraints for a futuristic giant 21-cm omniscope by using for the first time Markov Chain Monte Carlo (MCMC) methods on multiredshift full sky simulated data. Our results agree well with the usual Fisher matrix analysis on the three-dimensional flat sky power spectrum but only when the above-mentioned degeneracies are kept under control. In the opposite situation, Fisher results can be inaccurate. We show that these conditions can be fulfilled by combining cosmic microwave background measurements with multiple observation redshifts probing the beginning of EoR. This allows a precise reconstruction of the total optical depth, reionization duration and maximal spin temperature. Finally, we discuss the robustness of these results in presence of unresolved ionizing sources. Although most of the standard cosmological parameters remain weakly affected, we find a significant degradation of the background reionization parameter estimation in presence of nuisance ionizing sources.Comment: 22 pages, 18 figures, uses RevTex. References added, matches published versio

Particle Dark Matter Candidates

I give a short overview on some of the favorite particle Cold Dark Matter candidates today, focusing on those having detectable interactions: the axion, the KK-photon in Universal Extra Dimensions, the heavy photon in Little Higgs and the neutralino in Supersymmetry. The neutralino is still the most popular, and today is available in different flavours: SUGRA, nuSUGRA, sub-GUT, Mirage mediation, NMSSM, effective MSSM, scenarios with CP violation. Some of these scenarios are already at the level of present sensitivities for direct DM searches.Comment: 7 pages, 4 figures, 3 references added. Contribution to the proceedings of the TAUP 07 conference, Sep. 11-15, Sendai, Japa

Employment status and work-related problems of gastrointestinal cancer patients at diagnosis: a cross-sectional study

Objective To assess the employment status of patients with gastrointestinal cancer at diagnosis and to examine work-related problems of employed patients. Design New, consecutive patients were included at the Gastrointestinal Oncology Center Amsterdam, a one-stop, rapid access diagnostic assessment centre. Patients were interviewed on their employment status by a nurse. If (self-) employed, patients were asked to self-report on work-related problems, perceived distress (0-10), cancer-related problems, fatigue (MFI-20, range 4-20) and work ability (three WAI questions, range 0-10). Results Of all 333 included new consecutive patients (age range 32-89 years), 95 patients (28%) were (self-) employed at time of diagnosis, 179 (54%) were pensioners, and 59 were not working (18%). For the assessment of work-related problems, 45 (47%) of these 95 employed patients with cancer participated. Their mean age was 56 years, and patients had oesophageal/stomach (49%), colorectal (18%) or hepatic/pancreatic/biliary cancer (33%). Half of the employed patients (49%) were still at work, while 51% were on sick leave. The main reasons for sick leave were stress (35%), (scheduled) operation (26%), fatigue (17%) and pain (13%). Most patients on sick leave (70%) had no contact with their own occupational physician, although the majority (67%) would like to continue to work. Work-related problems were experienced by 73% of working patients. The mean work ability was 5.4, the mean general fatigue score was 11.5, and the mean distress score was 4.7. Employed patients on sick leave reported a lower work ability, more fatigue and higher distress but no more cancer-related problems compared with those still working. Conclusion A quarter of all patients with gastrointestinal cancer seen at an oncological centre are employed at time of diagnosis, and of these employed patients, 73% experience work-related problems. During diagnosis and treatment, information and support on work-related issues should be offered to patients with cancer as an essential part of high-quality oncological car

Vacuum Structure and the Axion Walls in Gluodynamics and QCD with Light Quarks

Large N gluodynamics was shown to have a set of metastable vacua with the gluonic domain walls interpolating between them. The walls may separate the genuine vacuum from an excited one, or two excited vacua which are unstable at finite N (here N is the number of colors). One may attempt to stabilize them by switching on the axion field. We study how the light quarks and the axion affect the structure of the domain walls. In pure gluodynamics (with the axion field) the axion walls acquire a very hard gluonic core. Thus, we deal with a wall "sandwich" which is stable at finite N. In the case of the minimal axion, the wall "sandwich" is in fact a "2-pi" wall, i.e., the corresponding field configuration interpolates between identical hadronic vacua. The same properties hold in QCD with three light quarks and very large number of colors. However, in the realistic case of three-color QCD the phase corresponding to the axion field profile in the axion wall is screened by a dynamical phase associated with the eta-prime, so that the gluon component of the wall is not excited. We propose a toy Lagrangian which models these properties and allows one to get exact solutions for the domain walls.Comment: 22 pages Latex, no figure

The Simulations Chain of the MURAVES Experiment

The MUon RAdiography of VESuvius (MURAVES) project is aimed at studying the summital cone of Mt. Vesuvius, an active and hazardous volcano near Naples, Italy. A detailed Monte Carlo simulation framework is necessary in order to investigate the effects of the experimental constraints and to perform comparisons with the actual observations. Our Monte Carlo setup combines a variety of Monte Carlo programs that address different aspects of cosmic muon simulation, from muon generation in the Earth’s upper atmosphere to the response of the detector, including the interactions with the material of the volcano. We will elaborate on the rationale for our technical choices, including the trade-off between speed and accuracy, and on the lessons learned, which are of general interest for similar use cases in muon radiograph