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A. T. Neagu

Publications and source records attributed to A. T. Neagu.

11 recordsLinked to original sources

Novel Silicon and GaAs Sensors for Compact Sampling Calorimeters

Two samples of silicon pad sensors and two samples of GaAs sensors are studied in an electron beam with 5 GeV energy from the DESY-II test-beam facility. The sizes of the silicon and GaAs sensors are about 9$\times$9 cm$^2$ and 5$\times$8 cm$^2$, respectively. The thickness is 500 micrometer for both the silicon and GaAs sensors. The pad size is about 5$\times$5 mm$^2$. The sensors are foreseen to be used in a compact electromagnetic sampling calorimeter. The readout of the pads is done by metal traces connected to the pads and the front-end ASICs at the edges of the sensors. For the silicon sensors, copper traces on a Kapton foil are connected to the sensor pads with conducting glue. The pads of the GaAs sensors are connected to bond-pads via aluminium traces on the sensor substrate. The readout is based on a dedicated front-end ASIC, called FLAME. Pre-processing of the raw data and deconvolution is performed with FPGAs. The whole system is orchestrated by a Trigger Logic Unit. Results are shown for the signal-to-noise ratio, the homogeneity of the response, edge effects on pads, and for signals due to the readout traces.

physics.ins-det

Input to the ESPPU: The LUXE Experiment

This document presents an overview of LUXE (Laser Und XFEL Experiment), an experiment that will combine the high-quality and high-energy electron beam of the European XFEL with a high-intensity laser, to explore the uncharted terrain of strong-field quantum electrodynamics. The scientific case, facility, and detector setup are presented together with an overview of the foreseen timeline and expected capital costs.

hep-ex

Technical Design Report for the LUXE Experiment

This Technical Design Report presents a detailed description of all aspects of the LUXE (Laser Und XFEL Experiment), an experiment that will combine the high-quality and high-energy electron beam of the European XFEL with a high-intensity laser, to explore the uncharted terrain of strong-field quantum electrodynamics characterised by both high energy and high intensity, reaching the Schwinger field and beyond. The further implications for the search of physics beyond the Standard Model are also discussed.

hep-ex

Performance and Moli`ere radius measurements using a compact prototype of LumiCal in an electron test beam

A new design of a detector plane of sub-millimetre thickness for an electromagnetic sampling calorimeter is presented. It is intended to be used in the luminometers LumiCal and BeamCal in future linear $e^+e^-$ collider experiments. The detector planes were produced utilising novel connectivity scheme technologies. They were installed in a compact prototype of the calorimeter and tested at DESY with an electron beam of energy 1-5 GeV. The performance of a prototype of a compact LumiCal comprising eight detector planes was studied. The effective Moli`ere radius at 5 GeV was determined to be (8.1 +/- 0.1 (stat) +/- 0.3 (syst)) mm, a value well reproduced by the Monte Carlo (MC) simulation (8.4 +/- 0.1) mm. The dependence of the effective Moli`ere radius on the electron energy in the range 1-5 GeV was also studied. Good agreement was obtained between data and MC simulation.

physics.ins-det

Detector Technologies for CLIC

The Compact Linear Collider (CLIC) is a high-energy high-luminosity linear electron-positron collider under development. It is foreseen to be built and operated in three stages, at centre-of-mass energies of 380 GeV, 1.5 TeV and 3 TeV, respectively. It offers a rich physics program including direct searches as well as the probing of new physics through a broad set of precision measurements of Standard Model processes, particularly in the Higgs-boson and top-quark sectors. The precision required for such measurements and the specific conditions imposed by the beam dimensions and time structure put strict requirements on the detector design and technology. This includes low-mass vertexing and tracking systems with small cells, highly granular imaging calorimeters, as well as a precise hit-time resolution and power-pulsed operation for all subsystems. A conceptual design for the CLIC detector system was published in 2012. Since then, ambitious R&D programmes for silicon vertex and tracking detectors, as well as for calorimeters have been pursued within the CLICdp, CALICE and FCAL collaborations, addressing the challenging detector requirements with innovative technologies. This report introduces the experimental environment and detector requirements at CLIC and reviews the current status and future plans for detector technology R&D.

physics.ins-det

Measurement of shower development and its Molière radius with a four-plane LumiCal test set-up

A prototype of a luminometer, designed for a future e+e- collider detector, and consisting at present of a four-plane module, was tested in the CERN PS accelerator T9 beam. The objective of this beam test was to demonstrate a multi-plane tungsten/silicon operation, to study the development of the electromagnetic shower and to compare it with MC simulations. The Molière radius has been determined to be 24.0 +/- 0.6 (stat.) +/- 1.5 (syst.) mm using a parametrization of the shower shape. Very good agreement was found between data and a detailed Geant4 simulation.

physics.ins-det

Study of tau-neutrino production at the CERN SPS

The DsTau project proposes to study tau-neutrino production in high-energy proton interactions. The outcome of this experiment are prerequisite for measuring the $ν_τ$ charged-current cross section that has never been well measured. Precisely measuring the cross section would enable testing of lepton universality in $ν_τ$ scattering and it also has practical implications for neutrino oscillation experiments and high-energy astrophysical $ν_τ$ observations. $D_s$ mesons, the source of tau neutrinos, following high-energy proton interactions will be studied by a novel approach to detect the double-kink topology of the decays $D_s \rightarrow τν_τ$ and $τ\rightarrowν_τX$. Directly measuring $D_s\rightarrow τ$ decays will provide an inclusive measurement of the $D_s$ production rate and decay branching ratio to $τ$. The momentum reconstruction of $D_s$ will be performed by combining topological variables. This project aims to detect 1,000 $D_s \rightarrow τ$ decays in $2.3 \times 10^8$ proton interactions in tungsten target to study the differential production cross section of $D_s$ mesons. To achieve this, state-of-the-art emulsion detectors with a nanometric-precision readout will be used. The data generated by this project will enable the $ν_τ$ cross section from DONUT to be re-evaluated, and this should significantly reduce the total systematic uncertainty. Furthermore, these results will provide essential data for future $ν_τ$ experiments such as the $ν_τ$ program in the SHiP project at CERN. In addition, the analysis of $2.3 \times 10^8$ proton interactions, combined with the expected high yield of $10^5$ charmed decays as by-products, will enable the extraction of additional physical quantities.

hep-ex

Higgs Physics at the CLIC Electron-Positron Linear Collider

The Compact Linear Collider (CLIC) is an option for a future e+e- collider operating at centre-of-mass energies up to 3 TeV, providing sensitivity to a wide range of new physics phenomena and precision physics measurements at the energy frontier. This paper is the first comprehensive presentation of the Higgs physics reach of CLIC operating at three energy stages: sqrt(s) = 350 GeV, 1.4 TeV and 3 TeV. The initial stage of operation allows the study of Higgs boson production in Higgsstrahlung (e+e- -> ZH) and WW-fusion (e+e- -> Hnunu), resulting in precise measurements of the production cross sections, the Higgs total decay width Gamma_H, and model-independent determinations of the Higgs couplings. Operation at sqrt(s) > 1 TeV provides high-statistics samples of Higgs bosons produced through WW-fusion, enabling tight constraints on the Higgs boson couplings. Studies of the rarer processes e+e- -> ttH and e+e- -> HHnunu allow measurements of the top Yukawa coupling and the Higgs boson self-coupling. This paper presents detailed studies of the precision achievable with Higgs measurements at CLIC and describes the interpretation of these measurements in a global fit.

hep-ex

Results from the October 2014 CERN test beam of LumiCal

A prototype of a luminometer, designed for a future e+e- collider detector, was tested in the CERN PS accelerator T9 testbeam. The objective of this test beam was to demonstrate a multi-plane operation, to study the development of the electromagnetic shower and to compare it with MC simulations.

physics.ins-det

Performance of fully instrumented detector planes of the forward calorimeter of a Linear Collider detector

Detector-plane prototypes of the very forward calorimetry of a future detector at an e+e- collider have been built and their performance was measured in an electron beam. The detector plane comprises silicon or GaAs pad sensors, dedicated front-end and ADC ASICs, and an FPGA for data concentration. Measurements of the signal-to-noise ratio and the response as a function of the position of the sensor are presented. A deconvolution method is successfully applied, and a comparison of the measured shower shape as a function of the absorber depth with a Monte-Carlo simulation is given.

physics.ins-det

Study of Peripheral Collisions of 56fe at 1 a Gev/c in Nuclear Emulsion

We have investigated the interactions of 1 A GeV 56Fe in nuclear emulsion. We measured the charge and the angular distributions of single and multiple charged relativistic particles emitted from peripheral interactions. We investigate a possible new method of separating interactions of electromagnetic origin. We provide the values of several parameters evaluated in a sample selected using the classical method, and the method proposed in this paper.

nucl-ex