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Author |
Fernandez Casani, A.; Orduña, J.M.; Sanchez, J.; Gonzalez de la Hoz, S. |
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Title |
A Reliable Large Distributed Object Store Based Platform for Collecting Event Metadata |
Type  |
Journal Article |
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Year |
2021 |
Publication |
Journal of Grid Computing |
Abbreviated Journal |
J. Grid Comput. |
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Volume |
19 |
Issue |
3 |
Pages |
39 - 19pp |
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Keywords |
Grid computing; Hadoop file system; Object-Based storage |
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Abstract |
The Large Hadron Collider (LHC) is about to enter its third run at unprecedented energies. The experiments at the LHC face computational challenges with enormous data volumes that need to be analysed by thousands of physics users. The ATLAS EventIndex project, currently running in production, builds a complete catalogue of particle collisions, or events, for the ATLAS experiment at the LHC. The distributed nature of the experiment data model is exploited by running jobs at over one hundred Grid data centers worldwide. Millions of files with petabytes of data are indexed, extracting a small quantity of metadata per event, that is conveyed with a data collection system in real time to a central Hadoop instance at CERN. After a successful first implementation based on a messaging system, some issues suggested performance bottlenecks for the challenging higher rates in next runs of the experiment. In this work we characterize the weaknesses of the previous messaging system, regarding complexity, scalability, performance and resource consumption. A new approach based on an object-based storage method was designed and implemented, taking into account the lessons learned and leveraging the ATLAS experience with this kind of systems. We present the experiment that we run during three months in the real production scenario worldwide, in order to evaluate the messaging and object store approaches. The results of the experiment show that the new object-based storage method can efficiently support large-scale data collection for big data environments like the next runs of the ATLAS experiment at the LHC. |
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Address |
[Fernandez Casani, Alvaro; Sanchez, Javier; Gonzalez de la Hoz, Santiago] Univ Valencia, Inst Fis Corpuscular IFIC, Burjassot, Spain, Email: alvaro.fernandez@ific.uv.es; |
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Springer |
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English |
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ISSN |
1570-7873 |
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Conference |
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Notes |
WOS:000692413100001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
4953 |
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Author |
LHCb Collaboration (Aaij, R. et al); Henry, L.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J. |
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Title |
Measurement of CP asymmetry in D-0 -> KS0 KS0 decays |
Type |
Journal Article |
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Year |
2021 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
104 |
Issue |
3 |
Pages |
L031102 - 11pp |
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Keywords |
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Abstract |
A measurement of the CP asymmetry in D-0 -> (KSKS0)-K-0 decays is reported, based on a data sample of proton-proton collisions collected by the LHCb experiment from 2015 to 2018, corresponding to an integrated luminosity of 6 fb(-1). The flavor of the D-0 candidate is determined using the charge of the D-*+/- meson, from which the decay is required to originate. The D-0 -> K+K- decay is used as a calibration channel. The time-integrated CP asymmetry for the D-0 -> (KSKS0)-K-0 mode is measured to be A(CP)(D-0 -> (KSKS0)-K-0) = (-3.1 +/- 1.2 +/- 0.4 +/- 0.2), where the first uncertainty is statistical, the second is systematic, and the third is due to the uncertainty on the CP asymmetry of the calibration channel. This is the most precise determination of this quantity to date. |
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Address |
[Leite, J. Baptista; Bediaga, I; Torres, M. Cruz; De Miranda, J. M.; dos Reis, A. C.; Gomes, A.; Massafferri, A.; Machado, D. Torres] Ctr Brasileiro Pesquisas Fis CBPF, Rio De Janeiro, Brazil |
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Publisher |
Amer Physical Soc |
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English |
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ISSN |
2470-0010 |
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Conference |
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Notes |
WOS:000692072800012 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4954 |
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Author |
Hirsch, M.; Maselek, R.; Sakurai, K. |
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Title |
Detecting long-lived multi-charged particles in neutrino mass models with MoEDAL |
Type |
Journal Article |
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Year |
2021 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
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Volume |
81 |
Issue |
8 |
Pages |
697 - 19pp |
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Keywords |
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Abstract |
A certain class of neutrino mass models predicts long-lived particles whose electric charge is four or three times larger than that of protons. Such particles, if they are light enough, may be produced at the LHC and detected. We investigate the possibility of observing those long-lived multi-charged particles with the MoEDAL detector, which is sensitive to long-lived particles with low velocities (beta) and a large electric charge (Z) with Theta equivalent to beta /Z less than or similar to 0.15. We demonstrate that multi-charged scalar particles with a large Z give three-fold advantage for MoEDAL; reduction of Theta due to strong interactions with the detector, and enhancement of the photon-fusion process, which not only increases the production cross-section but also lowers the average production velocity, reducing Theta further. To demonstrate the performance of MoEDAL on multi-charged long-lived particles, two concrete neutrino mass models are studied. In the first model, the new physics sector is non-coloured and contains long-lived particles with electric charges 2, 3 and 4. A model-independent study finds MoEDAL can expect more than 1 signal event at the HL-LHC (L=300fb-1) if these particles are lighter than 600, 1100 and 1430 GeV, respectively. These compare with the current ATLAS limits 650, 780 and 920 GeV for L=36fb-1. The second model has a coloured new physics sector, which possesses long-lived particles with electric charges 4/3, 7/3 and 10/3. The corresponding MoEDAL's mass reaches at the HL-LHC are 1400, 1650 and 1800 GeV, respectively, which compare with the current CMS limits 1450, 1480 and 1510 GeV for L=36fb-1. In a model-specific study we explore the parameter space of neutrino mass generation models and identify the regions that can be probed with MoEDAL at the end of Run-3 and the High-Luminosity LHC. |
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Address |
[Hirsch, Martin] Univ Valencia, Inst Fis Corpuscular, CSIC, C Catedrat Jose Beltran 2, Valencia 46980, Spain, Email: r.maselek@uw.edu.pl |
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Publisher |
Springer |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1434-6044 |
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Expedition |
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Conference |
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Notes |
WOS:000692138200002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4955 |
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Author |
ATLAS Collaboration (Aad, G. et al); Aparisi Pozo, J.A.; Bailey, A.J.; Cabrera Urban, S.; Cardillo, F.; Castillo, F.L.; Castillo Gimenez, V.; Costa, M.J.; Escobar, C.; Estrada Pastor, O.; Ferrer, A.; Fiorini, L.; Fullana Torregrosa, E.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gonzalez de la Hoz, S.; Gonzalvo Rodriguez, G.R.; Guerrero Rojas, J.G.R.; Higon-Rodriguez, E.; Lacasta, C.; Lozano Bahilo, J.J.; Mamuzic, J.; Marti-Garcia, S.; Martinez Agullo, P.; Mitsou, V.A.; Moreno Llacer, M.; Poveda, J.; Prades Ibañez, A.; Rodriguez Bosca, S.; Ruiz-Martinez, A.; Sabatini, P.; Salt, J.; Santra, A.; Sayago Galvan, I.; Soldevila, U.; Sanchez, J.; Torro Pastor, E.; Valero, A.; Valls Ferrer, J.A.; Villaplana Perez, M.; Vos, M. |
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Title |
Search for squarks and gluinos in final states with one isolated lepton, jets, and missing transverse momentum at root s=13 with the ATLAS detector |
Type |
Journal Article |
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Year |
2021 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
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Volume |
81 |
Issue |
7 |
Pages |
600 - 33pp |
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Keywords |
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Abstract |
The results of a search for gluino and squark pair production with the pairs decaying via the lightest charginos into a final state consisting of two W bosons, the lightest neutralinos ((chi) over tilde (0)(1)), and quarks, are presented: the signal is characterised by the presence of a single charged lepton (e(+/-) or mu(+/-)) from a W boson decay, jets, and missing transverse momentum. The analysis is performed using 139 fb(-1) of proton-proton collision data taken at a centre-of-mass energy root s = 13 delivered by the Large Hadron Collider and recorded by the ATLAS experiment. No statistically significant excess of events above the Standard Model expectation is found. Limits are set on the direct production of squarks and gluinos in simplified models. Masses of gluino (squark) up to 2.2 (1.4 ) are excluded at 95% confidence level for a light (chi) over tilde (0)(1). |
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Address |
[Duvnjak, D.; Jackson, P.; Kong, A. X. Y.; Oliver, J. L.; Ruggeri, T. A.; Sharma, A. S.; White, M. J.] Univ Adelaide, Dept Phys, Adelaide, SA, Australia |
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Publisher |
Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1434-6044 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000691564500001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4956 |
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Author |
LHCb Collaboration (Aaij, R. et al); Henry, L.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.; Sanchez Mayordomo, C. |
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Title |
Observation of new excited Bs0 states |
Type |
Journal Article |
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Year |
2021 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
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Volume |
81 |
Issue |
7 |
Pages |
601 - 11pp |
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Keywords |
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Abstract |
A structure is observed in the B +/- K -/+ mass spectrum in a sample of proton-proton collisions at centre-of-mass energies of 7, 8, and 13 TeV, collected with the LHCb detector and corresponding to a total integrated luminosity of 9 fb-1. The structure is interpreted as the result of overlapping excited Bs0</mml:msubsup> states. With high significance, a two-peak hypothesis provides a better description of the data than a single resonance. Under this hypothesis the masses and widths of the two states, assuming they decay directly to B +/- K -/+, are determined to be m1 = 6063.5 +/- 1.2 (stat) +/- 0.8 (syst) MeV
Gamma 1 = 26 +/- 4 (stat) +/- 4 (syst) MeV
m2 = 6114 +/- 3 (stat) +/- 5 (syst) MeV
Gamma 2 = 66 +/- 18 (stat) +/- 21 (syst) MeV
Alternative values assuming a decay through B +/- K -/+, with a missing photon from the B +/- -> B +/- gamma decay, which are shifted by approximately 45 MeV, are also determined. The possibility of a single state decaying in both channels is also considered. The ratio of the total production cross-section times branching fraction of the new states relative to the previously observed Bs20 state is determined to be 0.87 +/- 0.15 (stat)+/- 0.19 (syst). |
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Address |
[Leite, J. Baptista; Bediaga, I.; Torres, M. Cruz; De Miranda, J. M.; dos Reis, A. C.; Gomes, A.; Kucewicz, W.; Massafferri, A.; Machado, D. Torres] Ctr Brasileiro Pesquisas Fisicas CBPF, Rio De Janeiro, Brazil |
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Corporate Author |
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Thesis |
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Publisher |
Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1434-6044 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000691564500002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4957 |
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| Permanent link to this record |
