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Posters

Darreres entrades:
2020-02-21
15:09
LHCb - Measurement of CP violation in B0→D∗±D∓ decays at LHCb
Reference: Poster-2020-1030
Created: 2020. -1 p
Creator(s): Ibis, Philipp

The decay-time-dependent \ensuremath{C\!P} asymmetry in $B^0 \to D^{*\pm}D^{\mp}$ decays is measured using a data set corresponding to an integrated luminosity of $9$\ensuremath{\fb^{-1}} recorded by the \lhcb detector in proton-proton collisions at centre-of-mass energies of 7, 8 and $13$\aunit{Te\kern -0.1em V}. The analysis provides the most precise single measurement of \ensuremath{C\!P} violation in this decay channel to date. All parameters are consistent with their current world average values.

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2020-02-21
14:08
LHCb - Doubly charmed baryon searches and studies at LHC
Reference: Poster-2020-1029
Created: 2020. -1 p
Creator(s): Seman Bobulska, Dana

We present the latest results on the doubly charmed baryon searches and studies performed at the LHCb experiment. Precise studies of the properties of the doubly charmed baryon $\Xi_{cc}^{++}$, such as its lifetime, production, mass and decays, are presented. Recent search for its isospin partner, $\Xi_{cc}^{+}$ baryon, in $\Lambda_{c}^{+} K^{-} \pi^{+}$ decays using full Run1+Run2 data sample collected by the LHCb experiment, where no significant signal has been observed and upper limit on the production cross section times branching fraction with respect to the $\Xi_{cc}^{++} \rightarrow \Lambda_{c}^{+} K^{-} \pi^{+} \pi^{+}$ decay has been set, is discussed. Finally, ongoing studies and analyses are described, namely searches for the $\Xi_{cc}^{+}$ and $\Omega_{cc}^{+}$ baryons in more decay channels and preparation for Run3 data taking.

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LHCb poster
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2020-02-21
12:14
LHCb - Construction of the Upstream Tracker for the LHCb Upgrade
Reference: Poster-2020-1028
Created: 2020. -1 p
Creator(s): Ely, Scott Edward

The Upstream Tracker (UT) for the LHCb upgrade is currently being constructed. The UT, which sits just upstream of the dipole magnets, will enable a fast determination of track momentum so that slow tracks will not have to be subject to the downstream tracking. This will allow the fully software trigger to speed up by a factor of three. Modules consisting of a silicon sensor, hybrid flex circuit, and SALT ASIC are being fabricated at INFN Milano and at Syracuse University. After testing electronically for quality assurance, completed modules are then mounted on to supporting staves, also built at Syracuse. Finally, the fully populated staves are shipped to CERN to be installed in the experiment.

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LHCb poster
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2020-02-21
11:13
LHCb - Measurement of $|V_{cb}|$ with semileptonic Bs decays at LHCb
Reference: Poster-2020-1027
Created: 2020. -1 p
Creator(s): Manuzzi, Daniele

The measurement of the magnitude of the $V_{cb}$ element of the Cabibbo-Kobayashi-Maskawa matrix is of great importance in the validation of the Standard Model of particle physics. The current world averages for the inclusive and exclusive measurements of $|V_{cb}|$ are approximately three standard deviations apart, representing a long-standing puzzle in flavour physics. This poster presents the measurement of $|V_{cb}|$ using semileptonic $B_s^0$ decays produced in proton-proton collision data collected with the LHCb detector during the Run1 of the LHC. This is the first determination of $|V_{cb}|$ from exclusive decays at a hadron collider and the first using decays of the $B_s^0$ meson.

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2020-02-21
10:46
LHCb - Updated measurement of decay-time-dependent CP asymmetries in D0→K+K− and D0→π+π− decays at LHCb
Reference: Poster-2020-1026
Created: 2020. -1 p
Creator(s): Unverzagt, Daniel Joachim

The measurement of the decay-time dependent charge parity (CP) asymmetry in $\D^0 \to \pi^+ \pi^-$ and $\D^0 \to K^+ K^-$ is presented using proton-proton collisions. The data was recorded at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.4 $fb^{-1}$, with the LHCb detector. Neutral $D$ mesons which arise from semi-leptonic decays of b-flavoured hadrons are used.

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2020-02-21
10:41
LHCb - SMOG2 reconstruction performance: fixed-target physics at the LHCb experiment from Run3¶
Reference: Poster-2020-1025
Created: 2020. -1 p
Creator(s): Manuzzi, Daniele

The LHCb experiment started in 2015 a pioneering fixed-target pro- gramstudyingthecollisionsbetweenLHCprotonsandgastargetsinjected into the LHC beam pipe through a system called SMOG. The gas was free to spread between a wide area covering the pp luminous region, limiting the injectable gas species to noble ones. Fixed-target data were mostly acquired during special runs of limited duration to avoid interfering with the pp physics program. The upgrade of the SMOG program, SMOG2, will mainly consist in the installation of a confinement cell for the gas cov- ering a 20 cm long region upstream the nominal pp interaction point. This will allow to increase the gas density by up to two orders of magnitude and to potentially extend the gas species to be injected. Moreover, the large separation between the pp and SMOG2 regions opens the scenario of a simultaneous data-taking, provided that the reconstruction perfor- mance of both fixed-target and pp events is not significantly affected and the tight time constraints for the online reconstruction and selection are met. This poster contains some preliminary results for the efficiencies of the Run3 tracking sub-detectors: the performance are demonstrated to be comparable between pp and SMOG2 collisions and they do not degrade for pp when adding Helium or Argon gas targets

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2020-02-21
10:30
LHCb - Readout system for the phase I of the LHCb VELO upgrade
Reference: Poster-2020-1024
Created: 2020. -1 p
Creator(s): Fernandez Prieto, Antonio

The LHCb detector is being upgraded (during LS2 of the LHC) in order to cope it with a luminosity 5 times the the old detector and to remove the hardware trigger that will allow the operation the detector only with a pure software trigger. The tracking system of the detector is also being upgraded. A key part of this system is the VErtex LOcator (VELO) that is the primary tracking and vertex detector that surrounds the interaction point. The upgraded VELO will use a pixel detector read out at the LHC rate. This poster shows the specific electronics in the cavern and on the surface of LHCb needed to operate the VELO sub-detector. A especial emphasis is made on the VELO specific firmware of the back-end board (so-called PCIe40) and its different firmware flavours that configure its function in the experiment: SOL40 board dedicated to the Experiment Control System (ECS), Timing and Fast Control (TFC) and TELL40 board dedicated to the Data AcQuisition (DAQ). A lite version of the firmware, dedicated for production and hardware testing, which does not process the data is also presented.

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LHCb poster
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2020-02-21
10:22
LHCb - LHCb's Real-time Analysis Project and Development of Fast Tracking
Reference: Poster-2020-1023
Created: 2020. -1 p
Creator(s): Gunther, Andre

The LHCb experiment in the Run 3 environment of the LHC faces challenging rates of data containing particle decays of interest. In fact, expected signal rates alone are higher than current raw data storage capabilities. Therefore, LHCb is implementing a real-time data processing strategy and a reduced event model allowing triggering on fully reconstructed events and persisting an arbitrary set of reconstructed or raw objects. A crucial part of the real-time data analysis are fast and efficient tracking algorithms. This poster compares the two Forward Tracking algorithms currently under development for HLT1 and HLT2, respectively.

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2020-02-21
10:14
LHCb - LHCb VELO Upgrade Module Production
Reference: Poster-2020-1022
Created: 2020. -1 p
Creator(s): Svihra, Peter

The construction of the new LHCb Vertex Locator (VELO) detector is presented. The upgraded subsystem will play a crucial role in the tracking during data-taking runs starting in 2021, its main objective locating primary and secondary vertices. Compared to its predecessor, the main advantages are better resolution together with trigger-less readout at the maximal rate of 40 MHz. In total, VELO consists of 52 modules positioned in vacuum along the LHC beampipe, surrounding the interaction point. The modules are populated with 4 hybrid silicon pixel detectors with pixel pitch of 55 µm. Each of the sensors is read out by 3 VeloPix ASICs with 256x256 pixels. For experiment control and data propagation, sets of front-end hybrids and GBTx ASICs are utilized. The data are then sent through a vacuum feed-through board to an opto-and-power (OPB) board, which is connected to the rest of the experiment via optical fibres. Cooling of the whole module is achieved by phase transition of liquid CO2 using a custom-made silicon micro-channel substrate. The assembly of modules at both University of Manchester (Manchester, UK) and Nikhef (Amsterdam, NL) requires high precision in many aspects, therefore extensive procedures for the large-scale construction and its quality assurance have been deployed. The information during each step is uploaded to the online database and automatically analyzed, providing instantaneous information about quality of both components, performed tasks and whole modules. Final assembly of the whole system then takes place at University of Liverpool (Liverpool, UK) and is then transported to CERN (Geneva, CH).

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LHCb poster
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2020-02-20
10:02
LHCb-Real-time computing solutions based on FPGAs
Reference: Poster-2020-1021
Created: 2020. -1 p
Creator(s): Lazzari, Federico

With the slowdown of Moore’s law, the need for more effective, specialized computing solutions in HEP is increasing. This is particularly true for real-time processing of data in LHC high-rate experiments. One promising solution is the use of FPGA, that are a standard solution to many problems in the industry where large computing power is needed in high-tech devices that are produced in limited quantities (avionics, medical scanners, advanced radars, etc...). FPGAs still have a quick pace of progress, and are well suitable for highly parallel, high-speed environments, and in recent times are gaining popularity also in HEP. The LHCb experiment is currently undergoing a major upgrade for Run-3, in which the complete detector will be read out and events fully reconstructed at the full LHC crossing rate, while at the same time planning for future runs at even higher luminosities. In this context, intense R&D is being performed on alternative solutions to traditional general-purpose computing. We present the current status of efforts towards the use of FPGAs for several tasks: reconstruction of clusters in the pixel detector, track reconstruction in the VELO, and reconstruction of large sections of the tracking. This includes both simulations and tests with actual hardware in the realistic environment of the first prototypes of LHCb's upgraded DAQ system.

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LHCb poster
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Open Days 2013 Posters (58)
Open Days 2019 Posters (293)