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# Posters

2022-05-10
15:49
Status of the CSM FPGA Irradiation Test for the HL-LHC ATLAS Muon Spectrometer Upgrade

2022-05-05
09:10
LHCB - New measurements in ﬁxed-target collisions at LHCb
 Reference: Poster-2022-1071 Keywords:  smog  fixed-target collisions Created: 2022. -1 p Creator(s): Okamura, Shinichi The LHCb spectrometer has the unique capability to function as a fixed-target experiment by injecting gas into the LHC beampipe while proton or ion beams are circulating. The resulting beam+gas collisions cover an unexplored energy range that is above previous fixed-target experiments, but below the top RHIC energy for AA collisions. Here we present new results on antiproton and charm production from pHe, pNe, and PbNe fixed-target collisions at LHCb. Comparisons with various theoretical models of particle production and transport through the nucleus will be discussed. Related links:DIS2022: XXIX International Workshop on Deep-Inelastic Scattering and Related Subjects © CERN Geneva Access to files

2022-04-22
11:16
Production of charm hadrons in $p$Pb collisions with LHCb
 Reference: Poster-2022-1070 Created: 2022. -6 p Creator(s): Luo, Yiheng Open charm hadrons are collected by the LHCb detector in proton-lead collisions at $\sqrt{sNN}$=5.02 TeV. The excellent performance of particle reconstruction and identification in forward rapidity acceptance allows these charm states to be studied down to very low transverse momentum. This poster presents the LHCb measurement of the production of charm mesons, reconstructed in exclusive hadronic final states. Cold Nuclear Matter effects are studied, quantified by the nuclear modification factors, forward-backward production ratios. Comparisons to theoretical calculations, particularly the ones based on nuclear PDF, are also shown. Related links:XXIXth International Conference on Ultra-relativistic Nucleus-Nucleus Collisions © CERN Geneva Access to files

2022-04-20
11:57
Strangeness Enhancement in Small System at LHCb
 Reference: Poster-2022-1069 Created: 2022. -6 p Creator(s): Gu, Chenxi The enhanced production of strangeness was first proposed as a signature of the quark gluon plasma creation in heavy ion collisions. Recently, increased strangeness production is also observed experimentally in high multiplicity small systems such as pp and pPb collisions, where formation of QGP is not expected. In this study, production of prompt $D^+$ and $D^+_s$ in pPb collisions is measured with the LHCb detector at center-of-mass energy $\sqrt{sNN}=8.16$ TeV. LHCb's unique forward coverage together with its precise tracking and vertexing provides the possibility to measure the charm hadrons at very low transverse momentum with high accuracy. In addition to the recent results of prompt $D^+$ and $D^+_s$ production, we will also present $D^+_s$ to $D^+$ production ratio as a function of multiplicity and its comparisons to theoretical models. Related links:XXIXth International Conference on Ultra-relativistic Nucleus-Nucleus Collisions © CERN Geneva Access to files

2022-04-19
16:58
Poster: Fragmentation functions of identified charmed mesons
 Reference: Poster-2022-1068 Created: 2022. -6 p Creator(s): Sellam, Sara We present the progress of reconstructing the fragmentation functions of the charmed mesons, X(3872), ψ(2S) and Υ within reconstructed jets. The charmed mesons were measured within reconstructed anti-kT jets with R=0.5 in the pT range of 5 to 40GeV. The data stem from pp collisions at 13 TeV measured by the LHCb detector. The zT distributions of the mesons are reconstructed and compared to each other and to simulations. Since these mesons have very different quark contents, differences between their fragmentation might give insight into the underlying mechanisms of hadronization as well as the production mechanisms in the hard process in which they could be created. Related links:XXIXth International Conference on Ultra-relativistic Nucleus-Nucleus Collisions © CERN Geneva Access to files

2022-04-19
14:06
Prompt Λ+𝑐/𝐷0 ratio in peripheral PbPb collisions at 5.02 TeV by LHCb
 Reference: Poster-2022-1067 Created: 2022. -6 p Creator(s): Yang, Di Coalescence hadronization in QGP would enhance Λ+𝑐/𝐷0 at intermediate 𝑝𝑇 and are supposed to occur in PbPb collisions. The charmed baryon to meson ratio, Λ+𝑐/𝐷0 ratio is sensitive to hadronization, can provide important information on the charm hadronization process and formation of QGP. Prompt Λ+𝑐/𝐷0 ratio are measured in peripheral PbPb collisions at 𝑠𝑁𝑁‾‾‾‾√=5.02 TeV by LHCb, and are measured up to 𝑝𝑇=8 GeV/c and in the rapidity region of 2.0 to 4.5. This poster presents the Λ+𝑐/𝐷0 ratio together with comparisons to ALICE results and calculations using pythia plus color recombination and other models. Related links:XXIXth International Conference on Ultra-relativistic Nucleus-Nucleus Collisions © CERN Geneva Access to files

2022-04-14
12:14
Studies on charm-strange baryon Ξc+ in 8.16 TeV pPb collisions with LHCb
 Reference: Poster-2022-1066 Created: 2022. -6 p Creator(s): Litvinov, Roman The Ξc+ baryon is an open charm state comprised of an up, strange, and charm quark. For its peculiar composition with the presence of the strange quark, studies of baryon-to-baryon ratio of Ξc+ to Λc+ can provide valuable information on charm hadronization mechanisms, and possibly observe strangeness enhancement in small systems. We present the first study of Ξc+/Λc+ ratio in proton lead and lead proton collisions at the √s=8.16 TeV with the LHCb experiment. The baryons are reconstructed in their decay with a proton, a kaon, and a pion in about 30 nb−1 of data. The results will be compared to existing measurements in other collision systems and at different energies, and to recent theoretical predictions. Related links:XXIXth International Conference on Ultra-relativistic Nucleus-Nucleus Collisions © CERN Geneva Access to files

2022-04-14
11:54
Study of charmonium photoproduction in ultra-peripheral lead-lead collisions at LHCb
 Reference: Poster-2022-1065 Created: 2022. -5 p Creator(s): Wang, Xiaolin The LHCb detector is a single-arm forward spectrometer covering the pseudorapidity range 2 < 𝜂 < 5, designed for the study of particles containing bottom or charm quark. The study of exclusive vector meson photoproduction in ultra-peripheral lead-lead collisions is essential to understand physics at low Bjorken x. In particular, coherent charmonium mesons are promising probes of nuclear shadowing due to their sensitivity to the nuclear parton distribution function of gluons. In this presentation, we report the measurements of the differential coherent cross section productions as a function of rapidity for J/ψ meson in ultra-peripheral PbPb collisions at a nucleon-nucleon centre-of-mass energy of 5.02TeV. The J/ψ mesons are reconstructed in the dimuon decay channel using a data sample collected by the LHCb experiment in 2015, corresponding to an integrated luminosity about 10𝜇𝑏^(−1). The comparisons with theoretical predictions are also presented. More precise result from 2018 would come soon ! Related links:XXIXth International Conference on Ultra-relativistic Nucleus-Nucleus Collisions © CERN Geneva Access to files

2022-04-14
09:54
Searching for the gluon saturation scale at 𝑥∼10^{−5} with the LHCb detector using direct photons.
 Reference: Poster-2022-1064 Created: 2022. -5 p Creator(s): Da Silva, Cesar Luiz Because of the increasing gluon density towards small-𝑥, a regime where these densities reach a saturation (𝑄sat) is expected. The observation of this gluon saturated matter has several consequences to particle production and is a matter of an entire effective field theory, the Color Glass Condensate. The Large Hadron Collider beauty (LHCb) experiment has a privileged geometry for the search of the gluon saturation achieving an unprecedent small-𝑥 coverage. The most direct measurement of gluon densities and kinematics in hadronic collisions is the inverse Compton process (𝑞+𝑔→𝛾+𝑞). The LHCb experiment measured pairs of isolated photons correlated with hadrons from the quark fragmentation in pPb and Pbp collisions at 8.16 TeV probing a Bjorken-𝑥 between 10^{-5} Related links:XXIXth International Conference on Ultra-relativistic Nucleus-Nucleus Collisions © CERN Geneva Access to files

2022-01-13
14:33
NEW GENERATION OFFLINE SOFTWARE FOR THE LHCb UPGRADE I
 Reference: Poster-2022-1063 Created: 2022. -1 p Creator(s): Ferrillo, Martina The LHCb detector is undergoing a comprehensive upgrade for data taking in the LHC's Run 3, which is scheduled to begin in 2022. The increased data rate in Run 3 poses significant data-processing and handling challenges for the LHCb experiment. The offline computing and dataflow model is consequently also being upgraded to cope with the factor 30 increase in data volume and associated demands of user-data samples of ever-increasing size. Coordinating these efforts is the charge of the newly created Data Processing and Analysis (DPA) project. The DPA project is responsible for ensuring the LHCb experiment can efficiently exploit the Run 3 data, dealing with the data from the online system with central skimming/slimming (a process known as "Sprucing") and subsequently producing analyst-level ntuples with a centrally managed production system (known as "Analysis Productions") utilising improved analysis tools and infrastructure for continuous integration and validation.It is a multi-disciplinary project involving collaboration between computing experts, trigger experts and physics analysis experts. This talk will present the evolution of the data processing model, followed by a review of the various activities of the DPA project. The associated computing, storage and network requirements are also discussed. © CERN Geneva Access to files

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