A simulation tool for ALICE storage and computing resource usage

The LHC experiments produce many tens of petabytes of data each year, which must be stored, processed and analyzed. The CPU and storage resources required for these activities are planned for and requested on yearly basis. To make a better resource planning, a more fine-grained time prediction for the resource utilization is necessary, taking into account the LHC running conditions and schedule, the experiment-specific data management policies, scientific conferences demands and other criteria. To that end, we developed a flexible and highly configurable simulation tool, which performs a Discrete Event Simulation of the ALICE data flow processes. The tool consists of a Web GUI, through which the necessary parameters are entered and the results of the simulations are graphically visualized. In this paper, we describe the design of the simulation tool and present the preliminary results

A simulation tool for ALICE storage and computing resource usage

The LHC experiments produce many tens of petabytes of data each year, which must be stored, processed and analyzed. The CPU and storage resources required for these activities are planned for and requested on yearly basis. To make a better resource planning, a more fine-grained time prediction for the resource utilization is necessary, taking into account the LHC running conditions and schedule, the experiment-specific data management policies, scientific conferences demands and other criteria. To that end, we developed a flexible and highly configurable simulation tool, which performs a Discrete Event Simulation of the ALICE data flow processes. The tool consists of a Web GUI, through which the necessary parameters are entered and the results of the simulations are graphically visualized. In this paper, we describe the design of the simulation tool and present the preliminary results

The Hyperloop Train System

Hyperloop is the analysis train system for ALICE Run~3 and 4, replacing the LEGO Train System used in Run~1 and 2. It has been fully integrated with the {$\mathrm{O^2}$} analysis framework to enable analysis on the exceptionally large data samples recorded in Run~3 and 4. While {$\mathrm{O^2}$} allows distributed and efficient processing of the data, Hyperloop was designed to optimize the analysis process. The new train system allows task configuration integrated within the user interface and analysis shared between analysis group members. It enables fast and demanding analysis workflows to run on the Grid and on the ALICE Analysis Facilities. It also provides full archival of past configurations, changelogs and comparison tools. Hyperloop was developed using Java, JavaScript and a modern versatile framework, React, for optimizing the user experience. This document discusses the requirements, design and actual implementation of the tool, providing details on the concepts used. Hyperloop’s structure and components are presented, outlining the collection of features provided and distinctions from the LEGO Train System. An overview of the current status of the analysis in Run 3 is also presented

Performance of the ALICE Experiment at the CERN LHC

ALICE is the heavy-ion experiment at the CERN Large Hadron Collider. The experiment continuously took data during the first physics campaign of the machine from fall 2009 until early 2013, using proton and lead-ion beams. In this paper we describe the running environment and the data handling procedures, and discuss the performance of the ALICE detectors and analysis methods for various physics observables.ALICE is the heavy-ion experiment at the CERN Large Hadron Collider. The experiment continuously took data during the first physics campaign of the machine from fall 2009 until early 2013, using proton and lead-ion beams. In this paper we describe the running environment and the data handling procedures, and discuss the performance of the ALICE detectors and analysis methods for various physics observables.ALICE is the heavy-ion experiment at the CERN Large Hadron Collider. The experiment continuously took data during the first physics campaign of the machine from fall 2009 until early 2013, using proton and lead-ion beams. In this paper we describe the running environment and the data handling procedures, and discuss the performance of the ALICE detectors and analysis methods for various physics observables

K*(892)^0 and PHI(1020) production in Pb-Pb collisions at sqrt(sNN) = 2.76 TeV

The yields of the K*(892) and PHI(1020) resonances are measured in Pb-Pb collisions at sqrt(sNN) = 2.76 TeV through their hadronic decays using the ALICE detector. The measurements are performed in multiple centrality intervals at mid-rapidity (|y|<0.5) in the transverse-momentum ranges 0.3<pt<5 GeV/c for the K*(892)^0 and 0.5<pt<5 GeV/c for the PHI(1020). The yields of K*(892)^0 are suppressed in central Pb-Pb collisions with respect to pp and peripheral Pb-Pb collisions. This suppression is discussed in a scenario in which the K*(892)^0 decays during the evolution of the fireball and the decay products scatter, thus escaping detection through invariant-mass reconstruction. In contrast, the PHI(1020) meson, due to its long lifetime, decays outside the fireball. These particles are also used as probes to study the mechanisms of particle production. The shape of the pt distribution of the PHI(1020) meson, but not its yield, is reproduced fairly well by hydrodynamical models for central Pb-Pb collisions. In central Pb-Pb collisions at low and intermediate pt, the p/PHI(1020) ratio is flat in pt, while the p/pi and PHI(1020)/pi ratios show a pronounced increase and have similar shapes to each other. These results indicate that the shapes of the pt distributions of these particles in central Pb-Pb collisions are determined predominantly by the particle masses and radial flow. Finally, PHI(1020) production in Pb-Pb collisions is enhanced, with respect to the yield in pp collisions and the yield of charged pions, by an amount similar to the Lambda and Xi

Measurement of quarkonium production at forward rapidity in pppp collisions at s=7\sqrt{s} = 7 TeV

The inclusive production cross sections at forward rapidity of J/$\psi$, $\psi$(2S), $\Upsilon$(1S) and $\Upsilon$(2S) are measured in pp collisions at $\sqrt{s}$ = 7 TeV with the ALICE detector at the LHC. The analysis is based on a data sample corresponding to an integrated luminosity of 1.35 pb$^{-1}$. Quarkonia are reconstructed in the dimuon-decay channel and the signal yields are evaluated by fitting the $\mu^+\mu^-$ invariant mass distributions. The differential production cross sections are measured as a function of the transverse momentum $p_T$ and rapidity y, over the transverse momentum range 0 < $p_T$ < 20 GeV/c for J/$\psi$ and 0 < $p_T$ < 12 GeV/c for all other resonances and for 2.5 < y < 4. The measured cross sections integrated over $p_T$ and y, and assuming unpolarized quarkonia, are: $\sigma_{J/\psi}$=6.69 $\pm$ 0.04 $\pm$ 0.61 $\mu$ b, $\sigma_{\psi(2S)}$ = 1.13 $\pm$ 0.07 $\pm$ 0.14 $\mu$b, $\sigma_{\Upsilon(1S)}$ = 54.2 $\pm$ 5.0 $\pm$ 6.7 nb and $\sigma_{\Upsilon(2S)}$=18.4 $\pm$ 3.7 $\pm$ 2.2 nb, where the first uncertainty is statistical and the second one is systematic. These cross sections are obtained assuming unpolarized quarkonium production. The results are compared to measurements performed by other LHC experiments and to theoretical models.The inclusive production cross sections at forward rapidity of J/$\psi$, $\psi$(2S), $\Upsilon$(1S) and $\Upsilon$(2S) are measured in pp collisions at $\sqrt{s} = 7$ TeV with the ALICE detector at the LHC. The analysis is based in a data sample corresponding to an integrated luminosity of 1.35 pb$^{-1}$. Quarkonia are reconstructed in the dimuon-decay channel and the signal yields are evaluated by fitting the $\mu^+\mu^-$ invariant mass distributions. The differential production cross sections are measured as a function of the transverse momentum $p_{\rm T}$ and rapidity $y$, over the ranges $0 < p_{\rm T} < 20$ GeV/$c$ for J/$\psi$, $0 < p_{\rm T} < 12$ GeV/$c$ for all other resonances and for $2.5 < y < 4$. The measured cross sections integrated over $p_{\rm T}$ and $y$, and assuming unpolarized quarkonia, are: $\sigma_{J/\psi} = 6.69 \pm 0.04 \pm 0.63$ $\mu$b, $\sigma_{\psi^{\prime}} = 1.13 \pm 0.07 \pm 0.14$ $\mu$b, $\sigma_{\Upsilon{\rm(1S)}} = 54.2 \pm 5.0 \pm 6.7$ nb and $\sigma_{\Upsilon{\rm (2S)}} = 18.4 \pm 3.7 \pm 2.2$ nb, where the first uncertainty is statistical and the second one is systematic. The results are compared to measurements performed by other LHC experiments and to theoretical models.The inclusive production cross sections at forward rapidity of ${\mathrm{J}/\psi }$ , ${\psi (\mathrm{2S})}$ , $\Upsilon$ (1S) and $\Upsilon$ (2S) are measured in $\mathrm{pp}$ collisions at $\sqrt{s}=7~\mathrm{TeV}$ with the ALICE detector at the LHC. The analysis is based on a data sample corresponding to an integrated luminosity of 1.35 pb$^{-1}$ . Quarkonia are reconstructed in the dimuon-decay channel and the signal yields are evaluated by fitting the $\mu ^+\mu ^-$ invariant mass distributions. The differential production cross sections are measured as a function of the transverse momentum ${p_\mathrm{T}}$ and rapidity $y$ , over the ranges $0<{p_\mathrm{T}}<20$  GeV/c for ${\mathrm{J}/\psi }$ , $0<{p_\mathrm{T}}<12$  GeV/c for all other resonances and for $2.5<y<4$ . The measured cross sections integrated over ${p_\mathrm{T}}$ and $y$ , and assuming unpolarized quarkonia, are: $\sigma _\mathrm{{\mathrm{J}/\psi }}=6.69\pm 0.04\pm 0.63$   \upmu b, $\sigma _{\psi (\mathrm{2S})}=1.13\pm 0.07\pm 0.19$   \upmu b, $\sigma _{\Upsilon (\mathrm{1S})}=54.2\,\pm \, 5.0\pm 6.7$  nb and $\sigma _{\Upsilon (\mathrm{2S})}=18.4\,\pm \,3.7\,\pm \, 2.9$  nb, where the first uncertainty is statistical and the second one is systematic. The results are compared to measurements performed by other LHC experiments and to theoretical models