arXiv subjects
Publications and source records attributed to Akiya Miyamoto.
We are developing the vertex detector with a fine pixel CCD (FPCCD) for the international linear collider (ILC), whose pixel size is $5 \times 5$ $μ$m$^{2}$. To evaluate the performance of the FPCCD vertex detector and optimize its design, development of the software dedicated for the FPCCD is necessary. We, therefore, started to develop the software for FPCCD. In this article, the status of the study is reported.
We have studied the measurement accuracy of the forward-backward asymmetry of the $e^+e^- \rightarrow t\bar{t}$ process in the 6-jet mode at $\sqrt{s} = 500$ GeV with the ILD detector. In the analysis the vertex charges of b-jets were used to distinguish t from $\bar{t}$ in each event. The distribution of the cosine of the reconstructed polar angle of so identified t or $\bar{t}$ showed a clear forward-backward asymmetry. After the correction for charge misidentification the forward-backward asymmetry was determined to be $A^t_{FB} = 0.334 \pm 0.0079$ for 500 fb$^{-1}$ with the beam polarization combination of $P(e^+, e^-) = (+30\%, -80\%)$, demonstrating a very good statistical accuracy ($\sim 2\%$) even in the 6-jet mode.
Tau-pair process has been analyzed in the ILD detector model as a benchmark process for LoI. Results of background rejection, forward-backward asymmetry and polarization measurements are obtained with full detector simulation. Impact of detector parameters for tau-pair analysis is also discussed in this paper.
At the International Linear Collider (ILC), measurement of the beam profile at the interaction point (IP) is a key issue to achieve high luminosity. We studied the beam size measurement by combination of Pair Monitor and BeamCal. We obtained measurement accuracies of 2.7%, and 6.6% for the horizontal, and vertical beam sizes, respectively, for 50 bunch crossings.
At the international linear collider, measurement of the beam profile at the interaction point is a key issue to achieve high luminosity. We report a simulation study on a new beam profile monitor, called the pair monitor, which uses the hit distribution of the electron-positron pairs generated at the interaction point. We obtained measurement accuracies of 5.1%, 10.0%, and 4.0% for the horizontal, vertical, and longitudinal beam size, respectively, for 50 bunch crossings.
As a candidate of the vertex detector for experiments at ILC, fully depleted fine pixel CCDs (FPCCDs) are under development. We describe the basic concept of the FPCCD and report on preliminary results of the performance study of the first prototype FPCCD sensors.
We develop the vertex detector for the international linear collider (ILC) using the FPCCD (Fine Pixel CCD), whose pixel size is 5 x 5 um2. Together with the FPCCD sensor, a prototype of the readout ASIC was developed in 2008. The readout ASIC was confirmed to work correctly at slow readout speed (1.5 Mpix/sec). In this letter, we describe the status of the performance study for the readout ASIC.
The pair monitor is a beam profile monitor at interaction point (IP) for the international linear collider (ILC). We have designed and developed the pair monitor as a silicon pixel sensor which is located at about 400 cm from IP. As the first step to develop the pair monitor, the readout ASIC was developed. In this paper, test results of the readout ASIC and the future plan are reported.
The Particle Flow Analysis (PFA) is currently under intense studies as the most promising way to achieve precision jet energy measurements required at the future linear $e^+e^-$ collider. In order to optimize detector configurations and to tune up the PFA it is crucial to identify factors that limit the PFA performance and clarify the fundamental limits on the jet energy resolution that remain even with the perfect PFA and an infinitely granular calorimeter. This necessitates a tool to connect each calorimeter hit in particle showers to its parent charged track, if any, and eventually all the way back to its corresponding primary particle, while identifying possible interactions and decays along the way. In order to realize this with a realistic memory space, we have developed a set of C++ classes that facilitates history keeping of particle tracks within the framework of Geant4. This software tool, hereafter called J4HistoryKeeper, comes in handy in particular when one needs to stop this history keeping for memory space economy at multiple geometrical boundaries beyond which a particle shower is expected to start. In this paper this software tool is described and applied to a generic detector model to demonstrate its functionality.
The Detector Concept Report (DCR) consists of two parts, one for the physics and the other for ILC detectors. It has been prepared as the accompany document of the ILC Accelerator Reference Design Report. The detector DCR describes ILC detector designs, R&Ds on detector technologies and expected performances. The overview of the Detector DCR and the plan for the final release are presented.
It is widely recognized that good jet energy resolution is one of the most important requirements to the detectors for the future linear $e^+e^-$ collider experiments. The Particle Flow Analysis (PFA) is currently under intense studies as the most promising way to achieving the best attainable resolution. In order to clarify the fundamental limits on the jet energy resolution with the PFA, we have developed a set of C++ classes that facilitates history keeping of particle tracks within the framework of Geant4. In this paper this software tool is described and applied to a generic detector model so as to identify fundamental limiting factors to the PFA performance.
The International Technology Recommendation Panel distributed a list of questions to each major laboratory. Question 30, part b and d, were technology independent and related to the physics goals of the Linear Collider. An international panel, with representation from Asia, Europe, and the Americas, was formed by the World Wide Study during LCWS04 to formulate a response. This is given below and constitutes the response of the world-wide Linear Collider community.
JLC is an e+e- linear collider designed for experiments at Sqrt(s)=500 GeV with a luminosity of up to about 2.5x10^{34}/cm^2/s. In this talk, after describing the parameters of JLC accelerator and detector, the feasibilities of JLC to study Higgs, Top, and SUSY physics are presented based on the ACFA report.
We discuss the sensitivity of the $e^+ e^- \rightarrow W^+ W^-$ cross section at a future $e^+ e^-$ collider with $\sqrt{s}=500$GeV to the non-decoupling effects of a techni-$ρ$ like vector resonance. The non-decoupling effects are parametrized by the chiral coefficients of the electroweak chiral perturbation theory. We define renormalization scale independent chiral coefficients by subtracting the Standard Model loop contributions. We also estimate the size of the decoupling effects of the techni-$ρ$ resonance by using a phenomenological Lagrangian including the vector resonance.