{"title":"A general track fit based on triplets","authors":"A. Schöning","doi":"10.1016/j.nima.2025.170391","DOIUrl":null,"url":null,"abstract":"<div><div>This paper presents a general three-dimensional track fit based on hit triplets. The general track fit considers spatial hit and multiple Coulomb scattering uncertainties, and can also be extended to include energy losses. Input to the fit are detector-specific triplet parameters, which contain information about the triplet geometry (hit positions), the radiation length of the material and the magnetic field. Since the solution is given by an analytical closed-form, it is possible to use the same fitting code for all kind of tracking detectors.</div><div>Fitting formulas are given for the global track fit as well as for the local hit triplets. The latter allows filtering out triplets with poor fit quality at an early stage of track reconstruction. The construction and fit of local triplets is fully parallelizable, enabling accelerated computation with parallel hardware architectures. Formulas for the detector-specific triplet parameters are derived for the two most commonly used field configurations for tracking detectors, namely a uniform solenoidal field and gap spectrometer dipole. An algorithm to calculate the triplet parameters for an arbitrary magnetic field configuration is presented too.</div><div>This paper also includes a discussion of inherent track fit biases. Furthermore, a new method is proposed to accelerate track fitting by classifying tracking regimes and using optimal fit formulas.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1075 ","pages":"Article 170391"},"PeriodicalIF":1.5000,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0168900225001925","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"INSTRUMENTS & INSTRUMENTATION","Score":null,"Total":0}
引用次数: 0
Abstract
This paper presents a general three-dimensional track fit based on hit triplets. The general track fit considers spatial hit and multiple Coulomb scattering uncertainties, and can also be extended to include energy losses. Input to the fit are detector-specific triplet parameters, which contain information about the triplet geometry (hit positions), the radiation length of the material and the magnetic field. Since the solution is given by an analytical closed-form, it is possible to use the same fitting code for all kind of tracking detectors.
Fitting formulas are given for the global track fit as well as for the local hit triplets. The latter allows filtering out triplets with poor fit quality at an early stage of track reconstruction. The construction and fit of local triplets is fully parallelizable, enabling accelerated computation with parallel hardware architectures. Formulas for the detector-specific triplet parameters are derived for the two most commonly used field configurations for tracking detectors, namely a uniform solenoidal field and gap spectrometer dipole. An algorithm to calculate the triplet parameters for an arbitrary magnetic field configuration is presented too.
This paper also includes a discussion of inherent track fit biases. Furthermore, a new method is proposed to accelerate track fitting by classifying tracking regimes and using optimal fit formulas.
期刊介绍:
Section A of Nuclear Instruments and Methods in Physics Research publishes papers on design, manufacturing and performance of scientific instruments with an emphasis on large scale facilities. This includes the development of particle accelerators, ion sources, beam transport systems and target arrangements as well as the use of secondary phenomena such as synchrotron radiation and free electron lasers. It also includes all types of instrumentation for the detection and spectrometry of radiations from high energy processes and nuclear decays, as well as instrumentation for experiments at nuclear reactors. Specialized electronics for nuclear and other types of spectrometry as well as computerization of measurements and control systems in this area also find their place in the A section.
Theoretical as well as experimental papers are accepted.