scholarly journals Track Fitting for the Belle II Experiment

2019 ◽  
Vol 214 ◽  
pp. 02039 ◽  
Author(s):  
Stefano Spataro
Keyword(s):  
Magnetic Field ◽  
Pattern Recognition ◽  
Parameter Estimation ◽  
Tracking System ◽  
Center Of Mass ◽  
Drift Chamber ◽  
Pixel Detectors ◽  
Track Parameter ◽  
Belle Ii ◽  
Fitting In

The Belle II experiment has started to take data in 2018, studying e+e- collisions at the KEK facility in Tsukuba (Japan), in a center of mass energy range of the Bottomonium states. The tracking system includes a combination of hit measurements coming from the vertex detector, made of pixel detectors and double-sided silicon strip detectors, and acentral drift chamber, inside a solenoid of 1.5 T magnetic field. Once the pattern recognition routines have identified the track candidates, hit measurements are fitted taking into account the different information coming from different detectors, the energy loss in the materials and the inhomogeneity of the magnetic field. Track fitting is performed by the generic track-fitting software GENFIT, which includes a Kalman filter improved by a deterministic annealing filter, in order to reject outlier hits coming from not correctly associated hits by the pattern recognition. Several mass hypotheses are used in the fit, in order to achieve the best track parameter estimation for each particle kind. This article presents the design of the track fitting in the Belle II software, showing results in terms of track parameter estimation as well as computing performances.

scholarly journals Alignment for the first precision measurements at Belle II

2020 ◽  
Vol 245 ◽  
pp. 02023
Author(s):  
Tadeas Bilka ◽  
Jesus Abudinen ◽  
Karlheinz Georg Ackermann ◽  
Karol Mateusz Adamczyk ◽  
Patrick Ahlburg ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Cosmic Ray ◽  
Drift Chamber ◽  
Precision Measurements ◽  
Software Framework ◽  
Alignment Method ◽  
Vertex Detector ◽  
Detector Calibration ◽  
Target Performance ◽  
Belle Ii

On March 25th 2019, the Belle II detector recorded the first collisions delivered by the SuperKEKB accelerator. This marked the beginning of the physics run with vertex detector. The vertex detector was aligned initially with cosmic ray tracks without magnetic field simultaneously with the drift chamber. The alignment method is based on Millepede II and the General Broken Lines track model and includes also the muon system or primary vertex position alignment. To control weak modes, we employ sensitive validation tools and various track samples can be used as alignment input, from straight cosmic tracks to mass-constrained decays. With increasing luminosity and experience, the alignment is approaching the target performance, crucial for the first physics analyses in the era of Super-BFactories. We will present the software framework for the detector calibration and alignment, the results from the first physics run and the prospects in view of the experience with the first data.

scholarly journals Simultaneous Global and Local Alignment of the Belle II Tracking Detectors

2021 ◽  
Vol 251 ◽  
pp. 03028
Author(s):  
Tadeas Bilka ◽  
Jakub Kandra ◽  
Claus Kleinwort ◽  
Radek Zlebcik
Keyword(s):  
Tracking System ◽  
Drift Chamber ◽  
Local Alignment ◽  
Global Alignment ◽  
Recent Developments ◽  
Alignment Technique ◽  
Recorded Data ◽  
Alignment Strategy ◽  
Belle Ii ◽  
Global And Local

The alignment of the Belle II tracking system, composed of a pixel and strip vertex detectors and central drift chamber, is described by approximately sixty thousand parameters; from local alignment of sensors and wires to relative global alignment of the sub-detectors. In the next data reprocessing, scheduled since Spring 2021, we aim to determine all parameters in a simultaneous fit by Millepede II, where recent developments allow to achieve a direct solution of the full problem in about one hour and make it practically feasible for regular detector alignment. The tracking detectors and the alignment technique are described and the alignment strategy is discussed in the context of studies on simulations and experience obtained from recorded data. Preliminary results and further refinements based on studies of real Belle II data are presented.

Front-end electronics of the Belle II drift chamber

2014 ◽  
Vol 735 ◽  
pp. 193-197 ◽  
Author(s):  
Shoichi Shimazaki ◽  
Takashi Taniguchi ◽  
Tomohisa Uchida ◽  
Masahiro Ikeno ◽  
Nanae Taniguchi ◽  
...  
Keyword(s):  
Drift Chamber ◽  
Front End ◽  
Belle Ii

Test of a small prototype of the KLOE drift chamber in magnetic field

2000 ◽  
Vol 449 (1-2) ◽  
pp. 237-247 ◽  
Author(s):  
C Avanzini ◽  
G Ciapetti ◽  
E.De Lucia ◽  
F Lacava ◽  
C Luisi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Drift Chamber

scholarly journals Magnetized Particle Motion in γ-Spacetime in a Magnetic Field

Galaxies ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 76
Author(s):  
Ahmadjon Abdujabbarov ◽  
Javlon Rayimbaev ◽  
Farruh Atamurotov ◽  
Bobomurat Ahmedov
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Center Of Mass ◽  
Kerr Black Hole ◽  
Compact Object ◽  
Magnetic Interaction ◽  
Mass Energy ◽  
Circular Orbits ◽  
Center Of Mass Energy ◽  
Astrophysical Scenario

In the present work we explored the dynamics of magnetized particles around the compact object in γ-spacetime in the presence of an external asymptotically-uniform magnetic field. The analysis of the circular orbits of magnetized particles around the compact object in the spacetime of a γ-object immersed in the external magnetic field has shown that the area of stable circular orbits of magnetized particles increases with the increase of γ-parameter. We have also investigated the acceleration of the magnetized particles near the γ-object and shown that the center-of-mass energy of colliding magnetized particles increases with the increase of γ-parameter. Finally, we have applied the obtained results to the astrophysical scenario and shown that the values of γ-parameter in the range of γ∈(0.5,1) can mimic the spin of Kerr black hole up to a≃0.85, while the magnetic interaction can mimic the γ-parameter at γ∈(0.8,1) and spin of a Kerr black hole up to a≃0.3.

scholarly journals Association of Upper Extremity Pain With Softball Pitching Kinematics and Kinetics

2019 ◽  
Vol 7 (8) ◽  
pp. 232596711986517 ◽  
Author(s):  
Gretchen D. Oliver ◽  
Kenzie Friesen ◽  
Jeff W. Barfield ◽  
Kevin Giordano ◽  
Adam Anz ◽  
...  
Keyword(s):  
Upper Extremity ◽  
Ncaa Division I ◽  
Stride Length ◽  
National Collegiate Athletic Association ◽  
Tracking System ◽  
Center Of Mass ◽  
The United States ◽  
Division I ◽  
Trunk Rotation ◽  
Kinetic Chain

Background: There is a paucity of research regarding the relationship between fastpitch softball pitching mechanics and reported pain. Thus, understanding the pitching mechanics of athletes pitching with upper extremity pain and those pain free is paramount. Purpose: To examine lower extremity pitching mechanics, upper extremity kinetics, and upper extremity pain in National Collegiate Athletic Association (NCAA) Division I female softball pitchers. Study Design: Descriptive laboratory study. Methods: A total of 37 NCAA Division I female softball pitchers (mean age, 19.84 ± 1.28 years; mean height, 173.67 ± 7.77 cm; mean weight, 78.98 ± 12.40 kg) from across the United States were recruited to participate. Participants were divided into 2 groups: upper extremity pain (n = 13; mean age, 19.69 ± 1.18 years; mean height, 172.60 ± 11.49 cm; mean weight, 86.75 ± 13.02 kg) and pain free (n = 24; mean age, 19.91 ± 1.35 years; mean height, 174.26 ± 4.96 cm; mean weight, 74.78 ± 9.97 kg). An electromagnetic tracking system was used to obtain kinematic and kinetic data during the riseball softball pitch. Results: At foot contact ( F 3,33 = 7.01, P = .001), backward elimination regression revealed that stride length, trunk rotation, and center of mass (COM) significantly explained about 33% of variance with softball pitchers experiencing upper extremity pain (adjusted R 2 = 0.33). Conclusion: At foot contact, the kinematic variables of increased trunk rotation toward the pitching arm side, increased stride length, and a posteriorly shifted COM were associated with upper extremity pain in collegiate softball pitchers. Variables early in the pitching motion that do not set a working and constructive proximal kinetic chain foundation for the rest of the pitch to follow could be associated with breakdowns more distal in the kinetic chain, possibly increasing the susceptibility to upper extremity pain. Clinical Relevance: The identification of pitching mechanics associated with pain allows clinicians to develop exercises to avoid such mechanics. Avoiding mechanics associated with pain may help reduce the prevalence of pain in windmill softball pitchers as well as help coaches incorporate quantitative biomechanics into their instruction.

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