CERN Accelerating science

Posters

Posledne pridané:
2016-05-20
12:21
Measurement of the difference of time-integrated $CP$ asymmetries in $D^0 \to K^+K^-$ and $D^0 \to \pi^+\pi^-$ decays
Reference: Poster-2016-536
Keywords:  LHCb
Created: 2016. -1 p
Creator(s): Marino, Pietro

We present precision measurement of difference time-integrated $CP$ asymmetries, $\Delta A_{CP}$, in singly Cabibbo-suppressed modes $D^0 \to K^+K^-$ and $D^0 \to \pi^+\pi^-$, based on the full Run I LHCb data sample, corresponding to an integrated luminosity of $3\mathrm{fb}^{-1}$.

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The 16th International Conference on B-Physics at Frontier Machines
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Úplný záznam - Podobné záznamy
2016-05-09
16:01
HiRadMat: A high‐energy, pulsed beam, material irradiation facility
Reference: Poster-2016-535
Keywords:  HiRadMat facility  CERN  SPS  Targetry  440 GeV  protons
Created: 2016. -1 p
Creator(s): Charitonidis, Nikolaos; Fabich, Adrian

HiRadMat is a facility constructed in 2011, designed to provide high-intensity pulsed beams to an irradiation area where different material samples or accelerator components can be tested. The facility, located at the CERN SPS accelerator complex, uses a 440 GeV proton beam with a pulse length up to 7.2 μs and a maximum intensity up to 1E13 protons / pulse. The facility, a unique place for performing state-of-the art beam-to-material experiments, operates under transnational access and welcomes and financially supports, under certain conditions, experimental teams to perform their experiments.

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Úplný záznam - Podobné záznamy
2016-04-29
10:55
Geant4 hadronic and electromagnetic validation tests in LHCb
Reference: Poster-2016-534
Keywords:  LHCb
Created: 2016. -1 p
Creator(s): Griffith, Peter Noel

LHCb uses Geant4 to simulate the interactions of particles with the detector material and components. The simulation response can vary significantly due to modification of material description, of detector geometry, or of the Geant4 toolkit itself. Therefore, an extensive variety of tools have been developed to study the effects of Geant4 modification on the LHCb simulation framework and on stand-alone environments within the LHCb software infrastructure. These tools have proven to be very effective for investigating new and alternative models provided by Geant4, and also in identifying and fixing anomalous behaviours that arise from changes. The next goal is to have these validation tests run autonomously and periodically, alerting the relevant users when problems are detected. Quick and easy comparison of the results from different software versions and simulation models will be made possible through the web interface of the LHCb Performance and Regression testing system, LHCbPR.

Related links:
LHC Students poster session
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Úplný záznam - Podobné záznamy
2016-04-29
10:51
Novel Real-time Calibration and Alignment Procedure for LHCb Run II
Reference: Poster-2016-533
Keywords:  LHCb
Created: 2016. -1 p
Creator(s): Prouve, Claire

In order to achieve optimal detector performance the LHCb experiment has introduced a novel real-time detector alignment and calibration strategy for Run II of the LHC. For the alignment tasks, data is collected and processed at the beginning of each fill while the calibrations are performed for each run. This real time alignment and calibration allows the same constants being used in both the online and offline reconstruction, thus improving the correlation between triggered and offline selected events. Additionally the newly computed alignment and calibration constants can be instantly used in the trigger, making it more efficient. The online alignment and calibration of the RICH detectors also enable the use of hadronic particle identification in the trigger. The computing time constraints are met through the use of a new dedicated framework using the multi-core farm infrastructure for the LHCb trigger. An overview of all alignment and calibration tasks is presented and their performance is shown.

Related links:
LHC Students poster session
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Úplný záznam - Podobné záznamy
2016-04-29
10:41
Bs semileptonic asymmetry at LHCb
Reference: Poster-2016-532
Keywords:  LHCb
Created: 2016. -1 p
Creator(s): Dufour, Laurent

When neutral $B^{0}_{s,d}$ mesons evolve in time they can change into their own antiparticles. In this mixing process CP symmetry is not necessarily conserved, as the probability for a $B^{0}$ meson to change into a $\bar{B}^{0}$ meson can be different from the probability for the reverse process. The CP violation in the $B^{0}_{s}$ system as measured using semileptonic decays, defined as $a^{s}_{sl}$, is very small according to the Standard Model. However, earlier measurements of the semileptonic mixing asymmetry in both the $B_s^{0}$ and $B_d^{0}$ systems have shown a $3 \sigma$ deviation with respect to the Standard Model value. A measurement of $a^{s}_{sl}$ performed using $1 \text{fb}^{-1}$ of data collected at the LHCb detector is presented, together with an outlook to the updated $3 \text{fb}^{-1}$ result.

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LHC Students poster session
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Úplný záznam - Podobné záznamy
2016-03-29
10:51
$B0 \to Ds^{(*)}Ds^{(*)}$ and outlook of $B0 \to D^{(*)}D$ at LHCb
Reference: Poster-2016-531
Keywords:  LHCb
Created: 2016. -1 p
Creator(s): Belloli, Nicoletta

The measurement of the inclusive branching fraction of $B0s \to Ds^{(*)+} Ds^{(*)-}$ decay together with its contribution to the determination of $\Delta \Gamma{s}/ \Gamma {s}$ are presented. The branching fraction value is compatible with results from previous experiments, improving the world average. The $B0 \to D^+D^-$ and $B0 \to D^*D^{(*)}$ decays are used to measure the parameters associated with $CP$ Violation in those channels; while the analysis associated to the second channel is at an initial stage the first one is almost concluded, the values obtained for the sensitivity on the $CP$ observables show that LHCb can rival the results obtained by previous experiments.

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Conference - LHC students poster session
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Úplný záznam - Podobné záznamy
2016-03-29
10:13
Prospects for |V$_{ub}$| measurements at LHCb
Reference: Poster-2016-530
Keywords:  LHCb
Created: 2016. -1 p
Creator(s): Stefkova, Slavomira

Precise measurements of the quark coupling strength, $|V_{ub}|$, the least well known CKM element, allow a strong test of the unitarity of the CKM matrix. Previous measurements using exclusive and inclusive methods have resulted in values of $|V_{ub}|$ which are 3$\sigma$ apart. The first measurement of $|V_{ub}|$ at LHCb confirmed this tension using the $\Lambda^{0}_{b} \rightarrow p \mu^{-} \overline{\nu}$ decay. This strengthens the motivation to measure this quantity using different channels, one of them being purely leptonic decay $B^{+} \rightarrow \mu^{+} \mu^{-} \mu^{+} \nu$, which benefits from LHCb's very good muon identification ability. This mode had never been observed before. With recent lattice QCD calculations, LHCb can also constrain $|V_{ub}|$ using the $B^{0}_s \rightarrow K^{+} \mu^{-} \overline{\nu}$ decay where the theoretical uncertainty is significantly smaller.

Related links:
Conference - LHC students poster session
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Úplný záznam - Podobné záznamy
2016-03-22
13:59
LHCb measurements of $J/\psi$, and open charm cross-sections at $\sqrt{s}=13$TeV
Reference: Poster-2016-529
Created: 2016. -1 p
Creator(s): Muller, Dominik; Komarov, Ilya

Prompt $J/\psi$, $J/\psi$ from $b$-hadrons and prompt charm meson production is studied in proton-proton collisions at a center-of-mass energy of $\sqrt{s}=13$TeV at the LHCb detector with first application of a novel data streaming technique (Turbo steam). Cross-section measurements are performed as a function of the transverse momentum $p_T$ and the rapidity $y$ of the mesons in the region $p_T<15$GeV$/c$ and $2.0<y<4.5$. Obtained results were compared with expectations from QCD calculations. The ratios of the cross-sections with respect to Run 1 measurements are also determined. Comparison of the measured ratios values with theoretical predictions provided a new sensitive test of the QCD calculations.

Related links:
LHCb Poster
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Úplný záznam - Podobné záznamy
2016-03-18
15:46
Soft QCD and pA physics, with a focus on the ridge at LHCb
Reference: Poster-2016-528
Keywords:  LHCb
Created: 2016. -1 p
Creator(s): Dreimanis, Karlis

The LHCb experiment is a forward spectrometer originally designed for study of b and c hadron decays. However, it can be used in a much wider spectrum of physics analyses. The poster presented here highlights a few studies from the extensive range of soft QCD and heavy-ion physics analyses performed at the LHCb. A particular emphasis is placed on the observation of the two-particle angular correlations, so-called ridge effect, in the forward region. The results presented here serve as one of numerous examples of LHCb being a proven multi-purpose detector in the forward region.

Related links:
LCHb poster
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Úplný záznam - Podobné záznamy
2016-03-16
14:23
LHCb New algorithms for Flavour Tagging at the LHCb experiment
Reference: Poster-2016-527
Keywords:  LHCb
Created: 2016. -1 p
Creator(s): Fazzini, Davide

The Flavour Tagging technique allows to identify the B initial flavour, required in the measurements of flavour oscillations and time-dependent CP asymmetries in neutral B meson systems. The identification performances at LHCb are further enhanced thanks to the contribution of new algorithms.

Related links:
Conference 125th LHCC Meeting
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Open Days 2013 Posters (58)