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ALICE has upgraded many of its detectors for LHC Run 3 to operate in continuous readout mode recording Pb–Pb collisions at 50 kHz interaction rate without trigger. This results in the need to process data in real time at rates 100 times higher than during Run 2. In order to tackle such a challenge we introduced O2, a new computing system and the associated infrastructure. Designed and implemented during the LHC long shutdown 2, O2 is now in production taking care of all the data processing needs of the experiment. O2 is designed around the message passing paradigm, enabling resilient, parallel data processing for both the synchronous (to LHC beam) and asynchronous data taking and processing phases. The main purpose of the synchronous online reconstruction is detector calibration and raw data compression. This synchronous processing is dominated by the TPC detector, which produces by far the largest data volume, and TPC reconstruction runs fully on GPUs. When there is no beam in the LHC, the powerful GPU-equipped online computing farm of ALICE is used for the asynchronous reconstruction, which creates the final reconstructed output for analysis from the compressed raw data. Since the majority of the compute performance of the online farm is in the GPUs, and since the asynchronous processing is not dominated by the TPC in the way the synchronous processing is, there is an ongoing effort to offload a significant amount of compute load from other detectors to the GPU as well.

The Dimensions of Spirituality Inventory (DSI) is a 50-item quantitative assessment of spirituality. Whereas "spirituality" has seemed to some to be too vague for research purposes, the DSI follows earlier qualitative research in showing that usage of the word points to an intelligible conceptual structure. Instead of defining spirituality and then operationalizing it, as most extant instruments do, the DSI defines and operationalizes 21 relatively uncontroversial elemental components of spirituality, so the overall interpretation of spirituality can only emerge after factor analysis. Just as an alphabet flexibly expresses words and sentences, so the 21 DSI dimensions permit the discovery of latent constructs corresponding to cultural packages of spirituality at the present time. The DSI avoids culturally parochial formulations of items, thanks to intense multidisciplinary engagement among social scientists, scholars of religion, and psychologists of religion, and thus is suitable for cross-cultural application. This paper reports on a study based on a participant pool recruited for ExploringMyReligion.org, in part from Prolific (N = 820, after culling unreliable responses). The DSI is interpreted and validated in relation to several other relevant measures, and the factor analysis is strongly resonant with prior qualitative studies. The psychometric properties of the DSI make it usable as an overall spirituality scale as well as a sensitive inventory of types and configurations of spirituality. [ABSTRACT FROM AUTHOR]

ALICE will significantly increase its Pb–Pb data taking rate from the 1 kHz of triggered readout in Run 2 to 50 kHz of continuous readout for LHC Run 3. Updated tracking detectors are installed for Run 3 and a new twophase computing strategy is employed. In the first synchronous phase during the data taking, the raw data is compressed for storage to an on-site disk buffer and the required data for the detector calibration is collected. In the second asynchronous phase the compressed raw data is reprocessed using the final calibration to produce the final reconstruction output. Traditional CPUs are unable to cope with the huge data rate and processing demands of the synchronous phase, therefore ALICE employs GPUs to speed up the processing. Since the online computing farm performs a part of the asynchronous processing when there is no beam in the LHC, ALICE plans to use the GPUs also for this second phase. This paper gives an overview of the GPU processing in the synchronous phase, the full system test to validate the reference GPU architecture, and the prospects for the GPU usage in the asynchronous phase.

The Time Projection Chamber (TPC) of the ALICE experiment at the CERN LHC was upgraded for Run 3 and Run 4. Readout chambers based on Gas Electron Multiplier (GEM) technology and a new readout scheme allow continuous data taking at the highest interaction rates expected in Pb-Pb collisions. Due to the absence of a gating grid system, a significant amount of ions created in the multiplication region is expected to enter the TPC drift volume and distort the uniform electric field that guides the electrons to the readout pads. Analytical calculations were considered to correct for space-charge distortion fluctuations but they proved to be too slow for the calibration and reconstruction workflow in Run 3. In this paper, we discuss a novel strategy developed by the ALICE Collaboration to perform distortion-fluctuation corrections with machine learning and convolutional neural network techniques. The results of preliminary studies are shown and the prospects for further development and optimization are also discussed.

In LHC Run 3, ALICE will increase the data taking rate significantly to 50 kHz continuous read out of minimum bias Pb-Pb collisions. The reconstruction strategy of the online offline computing upgrade foresees a first synchronous online reconstruction stage during data taking enabling detector calibration, and a posterior calibrated asynchronous reconstruction stage. The significant increase in the data rate poses challenges for online and offline reconstruction as well as for data compression. Compared to Run 2, the online farm must process 50 times more events per second and achieve a higher data compression factor. ALICE will rely on GPUs to perform real time processing and data compression of the Time Projection Chamber (TPC) detector in real time, the biggest contributor to the data rate. With GPUs available in the online farm, we are evaluating their usage also for the full tracking chain during the asynchronous reconstruction for the silicon Inner Tracking System (ITS) and Transition Radiation Detector (TRD). The software is written in a generic way, such that it can also run on processors on the WLCG with the same reconstruction output. We give an overview of the status and the current performance of the reconstruction and the data compression implementations on the GPU for the TPC and for the global reconstruction.

In LHC Run 3, ALICE will increase the data taking rate significantly to 50 kHz continuous read-out of minimum bias Pb—Pb collisions. The reconstruction strategy of the online-offline computing upgrade foresees a first synchronous online reconstruction stage during data taking enabling detector calibration and data compression, and a posterior calibrated asynchronous reconstruction stage. Many new challenges arise, among them continuous TPC read-out, more overlapping collisions, no a priori knowledge of the primary vertex and of location-dependent calibration in the synchronous phase, identification of low-momentum looping tracks, and sophisticated raw data compression. The tracking algorithm for the Time Projection Chamber (TPC) will be based on a Cellular Automaton and the Kalman filter. The reconstruction shall run online, processing 50 times more collisions per second than today, while yielding results comparable to current offline reconstruction. Our TPC track finding leverages the potential of hardware accelerators via the OpenCL and CUDA APIs in a shared source code for CPUs and GPUs for both reconstruction stages. We give an overview of the status of Run 3 tracking including performance on processors and GPUs and achieved compression ratios.

ALICE is one of the four major LHC experiments at CERN. When the accelerator enters the Run 3 data-taking period, starting in 2021, ALICE expects almost 100 times more Pb-Pb central collisions than now, resulting in a large increase of data throughput. In order to cope with this new challenge, the collaboration had to extensively rethink the whole data processing chain, with a tighter integration between Online and Offline computing worlds. Such a system, code-named ALICE O2, is being developed in collaboration with the FAIR experiments at GSI. It is based on the ALFA framework which provides a generalized implementation of the ALICE High Level Trigger approach, designed around distributed software entities coordinating and communicating via message passing. We will highlight our efforts to integrate ALFA within the ALICE O2 environment. We analyze the challenges arising from the different running environments for production and development, and conclude on requirements for a flexible and modular software framework. In particular we will present the ALICE O2 Data Processing Layer which deals with ALICE specific requirements in terms of Data Model. The main goal is to reduce the complexity of development of algorithms and managing a distributed system, and by that leading to a significant simplification for the large majority of the ALICE users.

The green generation of [X.sup.+] (X = Br, I) using hydrogen peroxide in aqueous acetic acid allows access to aromatic heterocyclic halides in yields and purities comparable to syntheses employing N-bromosuccinimide. In activated and unsubstituted thiophene rings, regioselectivity is quantitative for positions a to the sulfur; pyrroles also give quantitative reactions, at least initially. Deactivated rings, including furans and thiazoles, as well as thiophenes with strongly electron- withdrawing groups showed little to no reactivity under the conditions investigated. The reaction shows remarkable functional group tolerance (to alcohol, nitro, alkyl, halo, and carbonyl groups), as shown through reaction with substituted phenols. In all bromination reactions, reaction yields and regiochemistry were very similar to reactions involving N-bromosuccinimide in tetrahydrofuran solvent. Key words: bromination, iodination, thiophenes, green chemistry, heterocyclic chemistry. La production verte de [X.sup.+] (X = Br, I) au moyen de peroxyde d'hydrogene dans une solution aqueuse d'acide acetique donne acces aux halogenures heterocycliques aromatiques avec des rendements et des puretes comparables a ceux des syntheses en utilisant le N-bromosuccinimide. Dans les noyaux thiophenes actives et non substitues, la regioselectivite est quantitative pour les positions en a du soufre; les pyrroles donnent aussi des reactions quantitatives, du moins initialement. Les noyaux desactives, y compris les furanes et les thiazoles, ainsi que les thiophenes porteurs de groupes fortement electroattracteurs ne manifestent que peu de reactivite, voire aucune, dans les conditions etudiees. La reaction presente une tolerance remarquable aux groupements fonctionnels (groupes alcool, nitro, alkyle, halo et carbonyle), comme le montre la reaction avec des phenols substitues. Dans toutes les reactions de bromation, le rendement et la regioselectivite etaient tres semblables a ceux des reactions faisant appel au N-bromosuccinimide en solution dans le tetrahydrofurane. [Traduit par la Redaction] Mots-cles: bromation, iodation, thiophenes, chimie verte, chimie heterocyclique., Introduction The tenets of green chemistry (1) include the use of nontoxic solvents and atom economy, and pursuing green alternatives to common reactions is an area of current interest. One [...]