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2015-08-26
10:37
Top Production at LHCb
Reference: Poster-2015-505
Created: 2015. -1 p
Creator(s): Santana Rangel, Murilo

Single and pair top production in the forward direction at the LHC allows for precision tests of the Standard Model. The observation of top quarks in 7 and 8 TeV data and prospects for precision measurements are shown.

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LHCb poster
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2015-08-26
10:31
Heavy flavour production in 13 TeV pp collisions
Reference: Poster-2015-504
Created: 2015. -1 p
Creator(s): Braun, Svende Annelies

This summer first data at the unprecedented energy of 13 TeV is collected at the LHC. This opens a new era in searches for new particles and precision tests of the Standard Model. Heavy flavour production plays an important role both as precision QCD test and as backgrounds for new particles. The first measurements of heavy flavour production are presented.

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LHCb poster
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2015-08-26
10:04
B → D*τν at LHCb
Reference: Poster-2015-503
Created: 2015. -1 p
Creator(s): Mendes Gandelman, Miriam

The decay B → D*τν is sensitive to new couplings, like those generated by charged Higgses. A 3σ discrepancy between the measured rate and the SM prediction has been reported by Babar. The first measurement performed at a hadron collider is presented.

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LHCb poster
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2015-08-26
09:42
LHCB : Exotic hadrons at LHCb
Reference: Poster-2015-502
Created: 2015. -1 p
Creator(s): Salazar De Paula, Leandro

The latest years have seen a resurrection of interest in searches for exotic states motivated by tantalising observations by Belle and CDF. Using the data collected at pp collisions at 7 and 8 TeV by the LHCb experiment we present the unambiguous new observation of exotic charmonia hadrons produced in B decays.

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LHCb poster
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2015-08-06
16:58
3D Monitoring of LHCb Inner Tracker
Reference: Poster-2015-501
Keywords:  LHCb
Created: 2015. -1 p
Creator(s): Sainvitu, Pascal

The positions of the Inner Tracker (IT) detectors of the LHCb experiment installed in the LHC at CERN are impacted by the LHCb dipole magnet powering. In the past the movements of the stations have been measured using standard survey methods during magnet tests in shutdown periods. But the survey targets are visible only in very narrow spaces and the access to the IT is very difficult, even impossible in the central region when the detector is closed. Finally the precision of the standard survey measurement is affected by the poor configuration. In 2013 and 2014, during the first long shutdown of the LHC (LS1), the CERN Survey team (EN/MEF-SU) in collaboration with the LHCb Technical Coordination and the EPFL (Ecole Polytechnique Fédérale de LAUSANNE, CH), developed a permanent monitoring system which has been tested and installed in order to allow the 3D position measurement of the IT stations, even during the run periods, with a precision of 100 microns at 1 sigma level. The 3D Monitoring system of the LHCb IT stations is based on opto-electronic BCAM (Brandeis CCD Angle Monitor) sensors, precise low material retro-reflective targets and mechanical elements. This paper summarizes the studies of the proposed system, its configuration and integration in the experiment, as well as the first results obtained.

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2015-07-27
11:28
b-flavour tagging in pp collisions
Reference: Poster-2015-500
Keywords:  LHCb
Created: 2015. -1 p
Creator(s): Birnkraut, Alex

An essential ingredient of all time-dependent CP violation studies of B mesons is the ability to tag the initial flavour of the B meson. The harsh environment of 7 and 8 TeV pp collisions makes this a particularly difficult enterprise. We report progresses in the flavour tagging of B0 and Bs mesons, including developments of novel techniques like the use of an opposite side charm tagger.

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2015-07-17
11:24
Layout of the ALICE detector (A Large Ion Collision Experiment), an experiment of the LHC
Schema du détecteur ALICE (A Large Ion Collision Experiment), une expérience de collision d'ions, pour le LHC.

Reference: Poster-2015-499
Keywords:  ALICE  LHC  set-up
Created: 2015. -1 p
Creator(s): Hatzifotiadou, Despina

The ALICE Set-up: 01. PMD 02. TRD 03. EMCAL 04. ACORDE 05. TPC 06. Absorber 07. Dipole Magnet 08-11. Muons 12. T0, V0, FMD 13. PHOS 14. ITS 15. TOF 16. HMPID 17. Solenoid Magnet 18. ZDC

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2015-06-19
11:40
LHCb : Behaviour of Multi-anode Photomultipliers in Magnetic Fields for the LHCb RICH Upgrde
Reference: Poster-2015-498
Keywords:  LHCb  MaPMT  magnetic field  magnetic shield
Created: 2015. -1 p
Creator(s): Gambetta, Silvia

A key feature of the LHCb upgrade, scheduled for 2019, is to remove the first level trigger and its data reduction from 40MHz to 1MHz, which is implemented in the on-detector readout electronics. The consequence for the LHCb Ring Imaging Cherenkov (RICH) detectors is that the Hybrid Photon Detectors need to be replaced as the readout chip is inside the detector vacuum. The baseline for replacement are Multianode Photomultiplier tubes (MaPMT) and new readout electronics. The MaPMTs will be located in the fringe field of the LHCb dipole magnet with residual fields up to 25 G. Therefore, their behaviour in magnetic fields is critical. Here we report about studies of the Hamamatsu models R11265 and H12700 in a magnetic field in an effort to qualify them for use in the LHCb RICH upgrade. Comparisons to the known model R7600 are also made. Measurements of the collection efficiency and gain were performed for all three space directions as a function of the magnetic field strength. In addition to measurements with bare tubes, measurements with different mu-metal shielding configurations were performed to optimize the configuration. This is important input for the layout of the upgraded LHCb RICH detector.

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LHCb poster
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2015-06-10
14:06
LHCb : LHCbVELO: Performance and Radiation Damage in LHC Run I and Preparationfor Run II
Reference: Poster-2015-497
Created: 2015. -1 p
Creator(s): Szumlak, Tomasz

LHCb is a dedicated experiment to study New Physics in the decays of heavy hadrons at the Large Hadron Collider (LHC) at CERN. Heavy hadrons are identified through their flight distance in the Vertex Locator (VELO). The VELO comprises 42 modules made of two n+-on-n 300 um thick half-disc silicon sensors with R-measuring and Phi-measuring micro-strips. In order to allow retracting the detector, the VELO is installed as two movable halves containing 21 modules each. The detectors are operated in a secondary vacuum and are cooled by a bi-phase CO2 cooling system. During data taking in LHC Run 1 the LHCb VELO has operated with an extremely high efficiency and excellent performance. The track finding efficiency is typically greater than 98%. An impact parameter resolution of less than 35 um is achieved for particles with transverse momentum greater than 1 GeV/c. An overview of all important performance parameters will be given. The VELO sensors have received a large and non-uniform radiation dose of up to 1.2 x 10^14 1 MeV neutron equivalent / cm^2 over the first LHC run. Type-inversion has been observed in regions close to the interaction point. Results of various radiation damage analyses will be presented. The preparations for LHC Run 2 are well under way and the VELO has already recorded tracks from injection line tests. The current status and plans for new operational procedures addressing the non-uniform radiation damage will be discussed.

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LHCb Poster
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2015-06-10
13:55
LHCb : Tracking system of the LHCb upgrade
Reference: Poster-2015-496
Created: 2015. -3 p
Creator(s): Szumlak, Tomasz

The upgrade of the LHCb experiment will run at an instantaneous luminosity of 2x10^33 cm^-2 s^-1 with a fully software based trigger, allowing to read out the detector at a rate of 40MHz. For this purpose, the full tracking system will be newly developed: the vertex locator (VELO) will be replaced by a pixel-based detector, withstanding the high radiation dose and providing an excellent track reconstruction with an efficiency of above 99% for all charged particles of interest. Upstream of the magnet, a silicon mico-strip detector with a high granularity and an improved acceptance coverage, called the Upstream Tracker (UT), will replace the current silicon strip tracker, and provide a rough momentum estimate. The tracking system downstream of the magnet will be replaced by the Scintillating Fibre tracker (SciFi), which will consist of 12 layers using 2.5m long scintillating fibres read out by silicon photo-multipliers, providing a spatial resolution better than 100 micron and resulting in a total momentum resolution of 0.4% for charged particles with a momentum of 20 GeV. We will present the performance of the tracking system for the LHCb upgrade, highlighting the improvements with respect to the current tracking system of LHCb, and review the track finding strategy. Special emphasize will be put on the need for fast track reconstruction in the software trigger, also giving examples of the potential use of parallelism in the pattern recognition. Finally, we will give some prospects of the physics performance with the LHCb upgrade for channels relying on excellent tracking capabilities.

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LHCb Poster
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Open Days 2013 Posters (58)