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## Event Index — an LHCb Event Search System

Journal of Physics: Conference Series. 2015. Vol. 664. No. 3. P. 032019-032019.

During LHC Run 1, the LHCb experiment recorded around 1011 collision events. This paper describes Event Index — an event search system. Its primary function is to quickly select subsets of events from a combination of conditions, such as the estimated decay channel or number of hits in a subdetector. Event Index is essentially Apache Lucene [1] optimized for read-only indexes distributed over independent shards on independent nodes.

Priority areas:
IT and mathematics

Language:
English

Science Bulletin 2020 Vol. 65 No. 23 P. 1983-1993

Using proton-proton collision data at centre-of-mass energies of s=7,8 and 13TeV recorded by the LHCb experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 9fb-1, the invariant mass spectrum of J/ψ pairs is studied. A narrow structure around 6.9GeV/c2 matching the lineshape of a resonance and a broad structure just above twice the J/ψ mass are observed. The deviation of the data from ...

Added: September 17, 2020

The European Physical Journal C - Particles and Fields 2021 Vol. 81 Article 599

High energy physics experiments rely heavily on the detailed detector simulation models in many tasks. Running these detailed models typically requires a notable amount of the computing time available to the experiments. In this work, we demonstrate a new approach to speed up the simulation of the Time Projection Chamber tracker of the MPD experiment at ...

Added: July 12, 2021

Journal of High Energy Physics 2020 Vol. 2020 No. 8 P. 1-27

The decays B+ → J/ψπ+π−K+ are studied using a data set corresponding to an integrated luminosity of 9 fb−1 collected with the LHCb detector in proton-proton collisions between 2011 and 2018. Precise measurements of the ratios of branching fractions with the intermediate ψ2(3823), χc1(3872) and ψ(2S) states are reported. The values are
B+→ψ2(3823)K+×ψ2(3823)→J/ψπ+π−B+→χc1(3872)K+×χc1(3872)→J/ψπ+π−=(3.56±0.67±0.11)×10−2,B+→ψ2(3823)K+×ψ2(3823)→J/ψπ+π−B+→ψ(2S)K+×ψ(2S)→J/ψπ+π−=(1.31±0.25±0.04)×10−3,B+→χc1(3872)K+×χc1(3872)→J/ψπ+π−B+→ψ(2S)K+×ψ(2S)→J/ψπ+π−=(3.69±0.07±0.06)×10−2,BB+→ψ2(3823)K+×Bψ2(3823)→J/ψπ+π−BB+→χc1(3872)K+×Bχc1(3872)→J/ψπ+π−=(3.56±0.67±0.11)×10−2,BB+→ψ2(3823)K+×Bψ2(3823)→J/ψπ+π−BB+→ψ(2S)K+×Bψ(2S)→J/ψπ+π−=(1.31±0.25±0.04)×10−3,BB+→χc1(3872)K+×Bχc1(3872)→J/ψπ+π−BB+→ψ(2S)K+×Bψ(2S)→J/ψπ+π−=(3.69±0.07±0.06)×10−2,
where the first uncertainty is statistical and the ...

Added: September 17, 2020

Journal of Physics: Conference Series 2018 Vol. 1085 No. 4 P. 042025-1-042025-6

Traces of electro-magnetic showers in the neutrino experiments may be considered as signals of dark-matter particles. For example, SHiP experiment is going to use emulsion film detectors similar to the ones designed for OPERA experiment from dark matter search. The goal of this research is to develop an algorithm that can identify traces of electro-magnetic ...

Added: December 8, 2017

Journal of Physics: Conference Series 2017 Vol. 898 No. 5 P. 1-5

© Published under licence by IOP Publishing Ltd. The Worldwide LHC Computing Grid provides access to data and computational resources to analyze it for researchers with different geographical locations. The grid has a hierarchical topology with multiple sites distributed over the world with varying number of CPUs, amount of disk storage and connection bandwidth. Job ...

Added: February 26, 2018

EDP Sciences, 2021

The 25th International Conference on Computing in High Energy and Nuclear Physics (CHEP), organised by CERN, took place as a virtual event from 17–21 May 2021. The conference attracted 1144 registered participants from 46 different countries. There were 207 scientific presentations made over the 5 days of the conference. These were divided between 30 long ...

Added: September 14, 2021

Journal of High Energy Physics 2020 Vol. 6 Article 110

This paper presents an analysis of the Λ0𝑏Λb0→ J/ψΛ angular distribution and the transverse production polarisation of Λ0𝑏Λb0 baryons in proton-proton collisions at centre-of-mass energies of 7, 8 and 13 TeV. The measurements are performed using data corresponding to an integrated luminosity of 4.9 fb−1, collected with the LHCb experiment. The polarisation is determined in a fiducial region ...

Added: September 17, 2020

Odessa Astronomical Publications 2013 No. 26/2 P. 309

Added: December 11, 2013

Odessa Astronomical Publications 2013 No. 26/2 P. 311-315

Now a day the task of comparative analysis of sample sources from different astronomical catalogs is becoming very topical for astronomers. It is useful both for the same spectral range data and for their cross-analysis for different spectral ranges. It is also important, that the real data from astronomical instruments is placed on-line. For the ...

Added: December 11, 2013

Cosmic Research 2017 Vol. 55 No. 6 P. 417-425

This work is devoted to studying the processes of the acceleration of plasma particles in thin current sheets that appear during magnetospheric substorms in the Earth’s magnetosphere tail. A numerical model of magnetic dipolarization accompanied by plasma turbulence has been constructed and studied. The model allows one to investigate the particle acceleration due to the ...

Added: July 19, 2018

Odessa Astronomical Publications 2014 Vol. 27 No. 2 P. 72-73

Added: November 24, 2014

The splitting in potential Crank-Nicolson scheme with discrete transparent boundary conditions for the Schrödinger equation on a semi-infinite strip / Cornell University. Series math "arxiv.org". 2013. No. arxiv: 1303.3471.

We consider an initial-boundary value problem for a generalized 2D time-dependent Schrödinger equation on a semi-infinite strip. For the Crank-Nicolson finite-difference scheme with approximate or discrete transparent boundary conditions (TBCs), the Strang-type splitting with respect to the potential is applied. For the resulting method, the uniform in time L2-stability is proved. Due to the ...

Added: March 16, 2013

Estimating the Density of States of Frustrated Spin Systems / Cornell University. Series cond-mat "arxiv.org". 2018. No. 1808.04340.

Estimating the density of states of systems with rugged free energy landscapes is a notoriously difficult task of the utmost importance in many areas of physics ranging from spin glasses to biopolymers to quantum computing. Some of the standard approaches suffer from a spurious convergence of the estimates to metastable minima, and these cases are ...

Added: October 17, 2018

Physics of Plasmas 2019 Vol. 26 No. 4 P. 1-9

This work is devoted to the investigation of particle acceleration during magnetospheric dipolarizations. A numerical model is presented
taking into account the four scenarios of plasma acceleration that can be realized: (A) total dipolarization with characteristic time scales of
3 min; (B) single peak value of the normal magnetic component Bz occurring on the time scale of ...

Added: April 16, 2019

NY: ACM, 2016

Added: August 30, 2018

Journal of High Energy Physics 2019 Vol. 1904 No. 77 P. 1-16

Heavy Neutral Leptons (HNLs) are hypothetical particles predicted by many extensions of the Standard Model. These particles can, among other things, explain the origin of neutrino masses, generate the observed matter-antimatter asymmetry in the Universe and provide a dark matter candidate.
The SHiP experiment will be able to search for HNLs produced in decays of heavy ...

Added: April 30, 2019

Odessa Astronomical Publications 2013 Vol. 26 No. 2 P. 308

Modern astronomical research programs need high-speed data transmission. The problem of the development and modernization of local networks and main channels is discussed. ...

Added: December 11, 2013

Springer, 2021

10th International Conference, IACC 2020, Panaji, Goa, India, December 5–6, 2020, Revised Selected Papers, Part II
series: Communications in Computer and Information Science (2021) volume 1368 ...

Added: July 7, 2021

2019 Vol. 61 P. 1-12

In this article we aim to highlight the problems related to the structure and stability of the
comparatively thin current sheets that were relatively recently discovered by space missions in
the magnetospheres of the Earth and planets, as well as in the solar wind. These magnetoplasma
structures are universal in collisionless cosmic plasmas and can play a key ...

Added: March 22, 2019

International Journal of Polymer Analysis and Characterization 2015 Vol. 20 No. 8 P. 743-753

This study produced for the first time composites based on polystyrene microspheres with nano-sized titania synthesized by sulfate and sol-gel methods, as well as commercial Hombifine N, Hombikat UV100, and Degussa P25. The starting samples and the composites were characterized by X-ray diffraction, scanning electron microscopy, nitrogen adsorption capacity, and IR spectroscopy. The highest content ...

Added: December 2, 2015

Пенза: ПГУ, 2016

В сборник трудов включены доклады ХХI-го Международного симпозиума «Надежность и качество», проходившего с 23 по 29 мая 2016 г. в городе Пензе.
Рассмотрены актуальные проблемы теории и практики повышения надежности и качества; эффективности внедрения инновационных и информационных технологий в фундаментальных научных и прикладных исследованиях, образовательных и коммуникативных системах и средах, экономике и юриспруденции; методов и средств ...

Added: May 27, 2016

Dordrecht, L., Cham, Heidelberg, NY: Springer, 2014

This book represents the combined peer-reviewed proceedings of the Seventh International Symposium on Intelligent Distributed Computing - IDC-2013, of the Second Workshop on Agents for Clouds - A4C-2013, of the Fifth International Workshop on Multi-Agent Systems Technology and Semantics - MASTS-2013, and of the International Workshop on Intelligent Robots - iR-2013. All the events were ...

Added: March 13, 2015

Программные системы: теория и приложения 2014 Т. 5 № 1 С. 191-244

Рассматривается подход, позволяющий выявить, для каких задач нужны суперкомпьютеры эксафлопсного класса. Возможности подхода рассмотрены на примерах актуальных задач материаловедения, физики конденсированного вещества и плотной плазмы, для решения которых необходимо атомистическое моделирование на современных и создаваемых в настоящее время суперкомпьютерах. Для каждой задачи проведено соответствие между набором изучаемых явлений и требуемым уровнем быстродействия (числа ядер) вычислительной ...

Added: August 11, 2014

Physical Review Special Topics - Accelerators and Beams 2012 Vol. 15 P. 053501

This paper describes the surface environment of the dense plasma arcs that damage rf accelerators, tokamaks, and other high gradient structures. We simulate the dense, nonideal plasma sheath near a metallic surface using molecular dynamics (MD) to evaluate sheaths in the non-Debye region for high density, low temperature plasmas. We use direct two-component MD simulations ...

Added: October 28, 2013