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Author Natochii, A. et al; Marinas, C.
Title Measured and projected beam backgrounds in the Belle II experiment at the SuperKEKB collider Type Journal Article
Year 2023 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 1055 Issue Pages 168550 - 21pp
Keywords Detector background; Lepton collider; Monte-Carlo simulation
Abstract The Belle II experiment at the SuperKEKB electron-positron collider aims to collect an unprecedented data set of 50 ab-1 to study CP-violation in the B-meson system and to search for Physics beyond the Standard Model. SuperKEKB is already the world's highest-luminosity collider. In order to collect the planned data set within approximately one decade, the target is to reach a peak luminosity of 6 x 1035 cm-2 s-1by further increasing the beam currents and reducing the beam size at the interaction point by squeezing the betatron function down to betay* = 0.3 mm. To ensure detector longevity and maintain good reconstruction performance, beam backgrounds must remain well controlled. We report on current background rates in Belle II and compare these against simulation. We find that a number of recent refinements have significantly improved the background simulation accuracy. Finally, we estimate the safety margins going forward. We predict that backgrounds should remain high but acceptable until a luminosity of at least 2.8 x 1035 cm-2 s-1is reached for betay* = 0.6 mm. At this point, the most vulnerable Belle II detectors, the Time-of-Propagation (TOP) particle identification system and the Central Drift Chamber (CDC), have predicted background hit rates from single-beam and luminosity backgrounds that add up to approximately half of the maximum acceptable rates.
Address [Natochii, A.; Browder, T. E.; Schueler, J.; Vahsen, S. E.] Univ Hawaii, Honolulu, HI 96822 USA, Email: natochii@hawaii.edu;
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:001056103200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5626
Permanent link to this record
 
 
Author Liptak, Z. et al; Marinas, C.
Title Measurements of beam backgrounds in SuperKEKB Phase 2 Type Journal Article
Year 2022 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 1040 Issue Pages 167168 - 19pp
Keywords
Abstract The high design luminosity of the SuperKEKB electron–positron collider will result in challenging levels of beam-induced backgrounds in the interaction region. Understanding and mitigating these backgrounds is critical to the success of the Belle II experiment. We report on the first background measurements performed after roll-in of the Belle II detector, a period known as SuperKEKB Phase 2, utilizing both the BEAST II system of dedicated background detectors and the Belle II detector itself. We also report on first revisions to the background simulation made in response to our findings. Backgrounds measured include contributions from synchrotron radiation, beam-gas, Touschek, and injection backgrounds. At the end of Phase 2, single-beam backgrounds originating from the 4 GeV positron Low Energy Ring (LER) agree reasonably well with simulation, while backgrounds from the 7 GeV electron High Energy Ring (HER) are approximately one order of magnitude higher than simulation. We extrapolate these backgrounds forward and conclude it is safe to install the Belle II vertex detector.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5496
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Author Belle II Collaboration (Abudinen, F. et al); Marinas, C.
Title B-flavor tagging at Belle II Type Journal Article
Year 2022 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 82 Issue 4 Pages 283 - 29pp
Keywords
Abstract We report on new flavor tagging algorithms developed to determine the quark-flavor content of bottom (B) mesons at Belle II. The algorithms provide essential inputs for measurements of quark-flavor mixing and charge-parity violation. We validate and evaluate the performance of the algorithms using hadronic B decays with flavor-specific final states reconstructed in a data set corresponding to an integrated luminosity of 62.8 fb(-1), collected at the gamma(4S) resonance with the Belle II detector at the SuperKEKB collider. We measure the total effective tagging efficiency to be epsilon(eff) = (30.0 +/- 1.2(stat) +/- 0.4(syst))% for a category-based algorithm and epsilon(eff) = (28.8 +/- 1.2(stat) +/- 0.4(syst))% for a deep-learning-based algorithm.
Address [Lautenbach, K.; Zani, L.] Aix Marseille Univ, CPPM, CNRS IN2P3, F-13288 Marseille, France
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000777159100005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5188
Permanent link to this record
 
 
Author Belle II Collaboration (Abudinen, F. et al); Marinas, C.
Title Precise Measurement of the D-0 and D+ Lifetimes at Belle II Type Journal Article
Year 2021 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 127 Issue 21 Pages 211801 - 9pp
Keywords
Abstract We report a measurement of the D-0 and D+ lifetimes using D-0 -> K-pi(+) and D+ -> K-pi(+)pi(+) decays reconstructed in e(+)e(-) -> c (c) over bar data recorded by the Belle II experiment at the SuperKEKB asymmetric-energy e(+)e(-) collider. The data, collected at center-of-mass energies at or near the (sic)(4S) resonance, correspond to an integrated luminosity of 72 fb(-1). The results, (tau)(D-0) = 410.5 +/- 1.1 (stat) +/- 0.8(syst) fs and tau(D-0) = 1030.4 +/- 4.7 (stat) +/- 3.1 (syst) fs, are the most precise to date and are consistent with previous determinations.
Address [Lautenbach, K.; Polat, G.; Serrano, J.; Zani, L.] Aix Marseille Univ, CPPM, CNRS IN2P3, F-13288 Marseille, France
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000721613700003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5032
Permanent link to this record
 
 
Author Belle II Collaboration (Abudinen, F. et al); Marinas, C.
Title Search for B+ -> K+nu(nu)over-bar Decays Using an Inclusive Tagging Method at Belle H Type Journal Article
Year 2021 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 127 Issue 18 Pages 181802 - 10pp
Keywords
Abstract A search for the flavor-changing neutral-current decay B+ -> K+nu(nu) over bar is performed at the Belle II experiment at the SuperKEKB asymmetric energy electron-positron collider. The data sample corresponds to an integrated luminosity of 63 fb(-1) collected at the Upsilon(4S) resonance and a sample of 9 fb(-1) collected at an energy 60 MeV below the resonance. Because the measurable decay signature involves only a single charged kaon, a novel measurement approach is used that exploits not only the properties of the B+ -> K+nu(nu) over bar decay, but also the inclusive properties of the other B meson in the Upsilon(4S) -> B (B) over bar event, to suppress the background from other B meson decays and light-quark pair production. This inclusive tagging approach offers a higher signal efficiency compared to previous searches. No significant signal is observed. An upper limit on the branching fraction of B+ -> K+nu(nu) over bar of 4.1 x 10(-5) is set at the 90% confidence level.
Address [Lautenbach, K.; Polat, G.; Serrano, J.; Zani, L.] Aix Marseille Univ, CPPM, CNRS IN2P3, F-13288 Marseille, France
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000712526000010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5020
Permanent link to this record
 
 
Author Wieduwilt, P.; Paschen, B.; Schreeck, H.; Schwenker, B.; Soltau, J.; Ahlburg, P.; Dingfelder, J.; Frey, A.; Gomis, P.; Lutticke, F.; Marinas, C.
Title Performance of production modules of the Belle II pixel detector in a high-energy particle beam Type Journal Article
Year 2021 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 991 Issue Pages 164978 - 15pp
Keywords DEPFET; DESY testbeam; Pixel detector; Belle II; Vertex detector
Abstract The Belle II experiment at the Super B factory SuperKEKB, an asymmetric e(+) e(-) collider located in Tsukuba, Japan, is tailored to perform precision B physics measurements. The centre of mass energy of the collisions is equal to the rest mass of the gamma (4S) resonance of m(gamma(4S)) = 10.58 GeV. A high vertex resolution is essential for measuring the decay vertices of B mesons. Typical momenta of the decay products are ranging from a few tens of MeV to a few GeV and multiple scattering has a significant impact on the vertex resolution. The VerteX Detector (VXD) for Belle II is therefore designed to have as little material as possible inside the acceptance region. Especially the innermost two layers, populated by the PiXel Detector (PXD), have to be ultra-thin. The PXD is based on DEpleted P-channel Field Effect Transistors (DEPFETs) with a thickness of only 75 μm. Spatial resolution and hit efficiency of production detector modules were studied in beam tests performed at the DESY test beam facility. The spatial resolution was investigated as a function of the incidence angle and improvements due to charge sharing are demonstrated. The measured module performance is compatible with the requirements for Belle II.
Address [Paschen, B.; Ahlburg, P.; Dingfelder, J.; Luetticke, F.] Univ Bonn, Phys Inst, Nussallee 12, D-53115 Bonn, Germany, Email: philipp.wieduwilt@phys.uni-goettingen.de;
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000686054900010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4941
Permanent link to this record
 
 
Author Belle II Collaboration (Abudinen, F. et al); Gomis, P.; Marinas, C.
Title Search for Axionlike Particles Produced in e(+)e(-) Collisions at Belle II Type Journal Article
Year 2020 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 125 Issue 16 Pages 161806 - 9pp
Keywords
Abstract We present a search for the direct production of a light pseudoscalar a decaying into two photons with the Belle II detector at the SuperKEKB collider. We search for the process e(+)e(-) -> gamma a, a -> gamma gamma in the mass range 0.2 < m(a) < 9.7 GeV/c(2) using data corresponding to an integrated luminosity of (445 +/- 3) pb(-1). Light pseudoscalars interacting predominantly with standard model gauge bosons (so-called axionlike particles or ALPs) are frequently postulated in extensions of the standard model. We find no evidence for ALPs and set 95% confidence level upper limits on the coupling strength g(a gamma gamma) of ALPs to photons at the level of 10(-3) GeV-1. The limits are the most restrictive to date for 0.2 < m(a) < 1 GeV/c(2).
Address [Polat, G.; Serrano, J.; Zani, L.] Aix Marseille Univ, CPPM, IN2P3, CNRS, F-13288 Marseille, France
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000577074900004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4567
Permanent link to this record
 
 
Author Belle II Collaboration (Adachi, I. et al); Gomis, P.; Marinas, C.
Title Search for an Invisibly Decaying Z ' Boson at Belle II in e(+)e(-) -> mu(+)mu(-) (e(+/-)mu(-/+)) Plus Missing Energy Final States Type Journal Article
Year 2020 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 124 Issue 14 Pages 141801 - 9pp
Keywords
Abstract Theories beyond the standard model often predict the existence of an additional neutral boson, the Z'. Using data collected by the Belle II experiment during 2018 at the SuperKEKB collider, we perform the first searches for the invisible decay of a Z' in the process e(+)e(-) -> mu(+)mu(-) Z' and of a lepton-flavor-violating Z' in e(+) e(-) -> e(+/-)mu(-/+)Z'. We do not find any excess of events and set 90% credibility level upper limits on the cross sections of these processes. We translate the former, in the framework of an L, – L, theory, into upper limits on the Z' coupling constant at the level of 5 x 10(-2) – 1 for M-z' <= 6 GeV/c(2).
Address [Jia, S.; Shen, C. P.; Zhou, X. Y.] Beihang Univ, Beijing 100191, Peoples R China
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000523637800002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4362
Permanent link to this record
 
 
Author Belle II Collaboration (Abudinen, F. et al); Gomis, P.; Marinas, C.
Title Measurement of the integrated luminosity of the Phase 2 data of the Belle II experiment Type Journal Article
Year 2020 Publication Chinese Physics C Abbreviated Journal Chin. Phys. C
Volume 44 Issue 2 Pages 021001 - 12pp
Keywords luminosity; Bhabha; digamma; Belle II
Abstract From April to July 2018, a data sample at the peak energy of the resonance was collected with the Belle II detector at the SuperKEKB electron-positron collider. This is the first data sample of the Belle II experiment. Using Bhabha and digamma events, we measure the integrated luminosity of the data sample to be (, where the first uncertainty is statistical and the second is systematic. This work provides a basis for future luminosity measurements at Belle II.
Address [Jia, S.; Li, S. X.; Zhou, X. Y.] Beihang Univ, Beijing 100191, Peoples R China
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1674-1137 ISBN Medium
Area Expedition Conference
Notes WOS:000509919700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4270
Permanent link to this record
 
 
Author Ahlburg, P. et al; Marinas, C.
Title EUDAQ – a data acquisition software framework for common beam telescopes Type Journal Article
Year 2020 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 15 Issue 1 Pages P01038 - 30pp
Keywords Data acquisition concepts; Detector control systems (detector and experiment monitoring and slow-control systems, architecture, hardware, algorithms, databases); Particle tracking detectors; Calorimeters
Abstract EUDAQ is a generic data acquisition software developed for use in conjunction with common beam telescopes at charged particle beam lines. Providing high-precision reference tracks for performance studies of new sensors, beam telescopes are essential for the research and development towards future detectors for high-energy physics. As beam time is a highly limited resource, EUDAQ has been designed with reliability and ease-of-use in mind. It enables flexible integration of different independent devices under test via their specific data acquisition systems into a top-level framework. EUDAQ controls all components globally, handles the data flow centrally and synchronises and records the data streams. Over the past decade, EUDAQ has been deployed as part of a wide range of successful test beam campaigns and detector development applications.
Address [Arling, J. -H.; Dreyling-Eschweiler, J.; Eichhorn, T.; Gregor, I. -M.; Irles, A.; Jansen, H.; Keller, J. S.; Kulis, S.; Lange, J.; Luetticke, F.; Perrey, H.; Peschke, R.; Pitzl, D.; Rossi, E.; Rubinsky, I.; Stanitzki, M.] Deutsch Elektronen Synchrotron DESY, Notkestr 85, D-22607 Hamburg, Germany, Email: jan.dreyling-eschweiler@desy.de
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1748-0221 ISBN Medium
Area Expedition Conference
Notes WOS:000525449600038 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4649
Permanent link to this record