Inter-university Attraction Pole meeting

Friday 2 Oct 2009, 09:30 → 18:00 Europe/Brussels

building D, room D.0.05 (Vrije Universiteit Brussel)

October 2009 session of our regular meeting. Due to the high number of attendants of the previous meetings, you are kindly invited to register to participate to the event. The meeting takes place on the Etterbeek campus of the VUB, in building D, room D.0.05. Coffee is served in building Q, in the 'Foyer onder de aula' IF YOU COME BY CAR you should know that the entrances to the campus are regulated by an automatic license plate recognition. As a visitor YOU WILL NEED A BAR CODE which you can find under 'maps'. You have to use gates 6 or 13 and put the bar code under the scanner. In case of problems there is an intercom which is connected to the security office. BYOB: please, Bring Your Own Badge Questions can be directed to Catherine De Clercq and Marleen Goeman at VUB.

09:30 welcome and coffee

1 Welcome

Speaker: Catherine De Clercq (VUB-exp)

Slides Declercq.pdf

2 News from the network

Speaker: Jean Marie Frere (ULB)

3 Strings vs. Condensed Matter: An Overview

Many experiments in condensed matter physics deal with "quantum critical" systems that are difficult to describe due to the absence of well-defined quasiparticles and the presence of strongly interacting excitations. The AdS/CFT duality provides new holographic methods to study these systems, by for instance mapping their transport properties to properties of black holes. We give a pedagogic overview of this approach to condensed matter physics, illustrating the main concepts by means of examples such as holographic superconductors and systems of cold atoms.

Speaker: Emiliano Imeroni (ULB-TH)

Slides Imeroni.pdf

4 Dark Matter simulations, dark disks, and implications for searches

If a dark disk component exists in our galaxy, it could impact significantly dark matter direct and indirect signals. I will review the possible morphologies of a dark disk, as obtained in recent advanced cosmological simulations. From this, deviations from the standard halo expectations in direct detection signals can be inferred. These include an enhancement of low-energy recoil events, an enhancement of the modulation signal as seen by DAMA, a shift in the modulation phase, an improvement of the general compatibility of DAMA with the limits set by other experiments. Whether this scenario is or is not realistic for the Milky-Way will also be discussed.

Speaker: Fu-Sin Ling (ULB-TH)

Slides Ling.pptx

5 Astrophysical high energy neutrino point sources search with a False Discovery Rate controlling procedure applied on AMANDA-II 2000-2006 data.

The Antarctic Muon And Neutrino Array (AMANDA) detector is a high energy neutrino detector installed in the Antarctic ice at the Geographic South Pole. Its final configuration, AMANDA-II, was taking data since 2000. Here are presented the analysis of 2000-2006 data with a statistical procedure controlling the False Discovery Rate, hence the confidence level, of a hypothetical discovery. This procedure aims at the detection of neutrino point sources without any assumption about the possible source characteristics. It also has the advantage of naturally taking into account the trial factor effect encountered in multiple hypothesis testing.

Speaker: Mathieu Labare (ULB-EXP)

Slides PAI_Labare.pdf

6 Board meeting

12:30 lunch break

7 Standard Model searches on intersecting D-branes

I will present a specific class of string theory compactifications with Standard Model-like properties. After discussing generalities of intersecting D-brane models, I will show some statistical results for a specific orbifold background Z6'.

Speaker: Honecker Gaby (KUL)

Slides IAP-honecker.pdf

8 Towards the start-up of CMS detector: CMS tracker alignment

CMS detector is complete and is ready to record LHC collisions. Precise and prompt alignment and calibration will be crucial to the performance of the CMS detector. The CMS silicon strip tracker is the largest device of this type ever built for detection of charge particles produced in beam-beam collisions. The all-silicon design of the CMS Tracker poses new challenges in aligning a complex system with 15148 silicon strip and 1440 silicon pixel modules. For optimal track-parameter resolution, the position and orientation of its modules need to be determined with a precision of several micrometers. The detector was installed inside CMS in December 2007, and it was commissioned during the summer 2008. During the 2008 Cosmic Run at Four Tesla (CRAFT) the CMS tracker operated for the first time with the rest of the CMS detectors and about 6 millions of cosmic muons were reconstructed. With this amount of data it was possible to test the detector performances, to align the detector and to test the CMS track reconstruction algorithms with real cosmic events. For the modules well illuminated by cosmic ray particles, the ultimate precision has been achieved with data from the silicon modules traversed in-situ by charged muons used in combination with survey measurements. Description of the calibration and alignment work flow for such detector will be mentioned and the achieved precision on the alignment will be described together with an outlook for expected tracking performance with the first collisions.

Speaker: Stephanie Beauceron (VUB-EXP)

Slides IAP-beauceron.pdf

9 Extra-Dimensions and other Exotic searches with Dijet and Monojet events with the CMS detector

High transverse momentum jets are a powerful tool for discovery of new physics in the early running stages of the CERN LHC pp collider. CMS collaboration will analyze jets in the so called monojet and dijet events to probe exotic physics beyond the standard model. Here we present in detail search plans for different initial integrated luminosities and LHC energies scenarios. The missing transverse energy + monojet signature has been investigated as a probe for the discovery of large extra dimensions, as predicted by phenomenological ADD model, with the CMS detector. Signal and background samples were simulated and studied in detail. Techniques to estimate the background contributions via data-driven methods are discussed. The discovery reach is studied for initial luminosities at LHC at $\sqrt{s}$ = 14 TeV and $\sqrt{s}$ = 10 TeV. taking into account systematic uncertainties. It is shown that a significant improvement of the existing limits can be obtained with early data. Concerning the dijets, we present CMS plans to search for physics beyond the standard model and studies of jet trigger, jet cleanup, jet response versus $\eta$, optimization of $\eta$ cuts, and the dijet mass resolution. Estimates are presented for both the QCD background and signals of new physics with a focus on the integrated luminosities 10 pb$^-$1, 100 pb$^-$1, and 1 fb$-^$1 expected early in LHC running. The inclusive cross section as a function of jet p$_T$ is a first simple measure of QCD dijets which is sensitive to a 3 TeV contact interaction with only 10 pb$^-$1. With the dijet mass distribution we expect to be able to convincingly observe dijet resonances with large cross sections, such as a 2 TeV excited quark which produces a 13 $\sigma$ signal with 100 pb$^-$1. With the dijet ratio, a simple angular measurement, we expect to be able to discover a contact interaction scale $\Lambda$+ of 4, 7 and 10 TeV for integrated luminosities of 10 pb$^-$1, 100 pb$^-$1, and 1 fb$^-$1 respectively. Using the dijet ratio we can discover or confirm a dijet resonance, and eventually measure its spin. With 100 pb$^-$1 a 2 TeV resonance with the production rate of an excited quark produces a convincing signal in the dijet ratio.

Speaker: Marco Cardaci (UA)

Slides TalkIAP09Cardaci.pdf

15:45 coffee break

10 Pixel detector developments

The development of pixel detector applications developed in CP3 using different technologies will be presented. The first part of the talk will include a review of the different technologies available for pixel detectors. The second part will introduce the SOI pixel project developed in CP3 using 2um DICE-UCL technology. The last part of the talk will introduce NA62 EOC read-out chip design, done using 130nm technology from IBM.

Speaker: Elena Martin (UCL-EXP)

Slides Martina.pdf

11 String theory on AdS3 with RR fluxes

I will review recent progress concerning the quantization of strings in AdS3*S3 with RR fluxes. In particular I will present the current algebra of sigma models on supergroup manifolds with vanishing dual Coxeter number. Then I will explain the construction of the generators of the spacetime symmetry algebra for string theory in AdS3*S3.

Speaker: Raphael Benichou (VUB-TH)

Slides IAP-benichou.pdf

12 Forward Physics capabilities of CMS with the CASTOR calorimeter

The Cerenkov calorimeter CASTOR, located 14.4 m downstream of the CMS interaction point, extends the pseudorapidity coverage of the CMS detector to the region −6.6 < < −5.2 and enables to study forward physics events in which particles are produced close to the proton beam direction. After having described the CASTOR calorimeter, its capabilities and physics program will be presented. The accent will be put on the study of multi-jets events with a forward jet, which gives access to the parton dynamics beyond the usual DGLAP one and to the investigation of the BFKL-like QCD evolution. The use of the CASTOR calorimeter as a veto detector to require the absence of forward activity, which is of prime importance in the study of diffractive events, will also be discussed.

Speaker: Benoit Roland (UA)

Slides Roland.pdf