Abstract The ATLAS physics program at the High Luminosity LHC (HL-LHC) calls for a precision in the luminosity measurement of 1%. A larger uncertainty would represent the dominant systematic error in ...precision measurements, including those in the Higgs sector. To fulfill such requirement in an environment characterized by up to 140 simultaneous interactions per crossing (200 in the ultimate scenario), ATLAS will feature several luminosity detectors. At least some of them must be both calibratable in the van der Meer scans at low luminosity and able to measure up to the highest values. LUCID-3, the upgrade of the present ATLAS luminometer (LUCID-2), will fulfill such a condition. The reasons for an upgrade of LUCID-2 and the envisaged solutions are discussed and a description of the LUCID-3 project is given. Finally, the first results obtained with the prototypes installed in ATLAS during the present LHC Run-3 are discussed as means of the validation of the final design.
The ATLAS luminosity monitor, LUCID (LUminosity Cherenkov Integrating Detector), had to be upgraded for the second run of the LHC accelerator that started in spring 2015. The increased energy of the ...proton beams and the higher luminosity required a redesign of LUCID to cope with the more demanding conditions. The novelty of the LUCID-2 detector is that it uses the thin quartz windows of photomultipliers as Cherenkov medium and a small amounts of radioactive 207Bi sources deposited on to these windows to monitor the gain stability of the photomultipliers. The result is a fast and accurate luminosity determination that can be kept stable during many months of data taking. LUCID-2 can also measure the luminosity accurately online for each of the up to 2808 colliding bunch pairs in the LHC . These bunch pairs are separated by only 25 ns and new electronics has been built that can count not only the number of pulses above threshold but also integrate the pulses.
A review of the ATLAS forward physics results is given with particular emphasis on the aspects of relevance for the cosmic rays community. These include proton-proton cross section measurements at ...s=7 TeV, diffractive physics studies using rapidity gaps, measurements of energy flow as a function of pseudorapidity, and the first cross section measurement performed in the recently started Run 2 at s=13 TeV. The ATLAS future perspectives will also be discussed, focused on the phase 1 upgrade project AFP, underlying its potential for a wide forward physics program both at low and high luminosity.
The luminosity monitor LUCID (LUminosity Cherenkov Integrating Detector) employed in the ATLAS experiment at the LHC had to be upgraded for the second run of LHC (Run 2) that started in spring 2015. ...The increased energy of the proton beams and the higher luminosity implied that the Photomultipliers of the original LUCID detector had to be replaced for Run 2 to cope with the more demanding conditions. This paper deals with choice and characterisation of the Photomultipliers used for the new version of LUCID.
We present an analysis of the existing data on charmonium hadro-production based on non-relativistic QCD (NRQCD) calculations at the next-to-leading order (NLO). All the data on J/ψ and ψ(2S) ...production in fixed-target experiments and on pp collisions at low energy are included. We find that the amount of color-octet contribution needed to describe the data is about 1/10 of that found at the Tevatron.
Thin pixel development for the SuperB silicon vertex tracker Rizzo, G.; Avanzini, C.; Batignani, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2011, Letnik:
650, Številka:
1
Journal Article
Recenzirano
The high luminosity SuperB asymmetric
e
+
e
−
collider, to be built near the INFN National Frascati Laboratory in Italy, has been designed to deliver a luminosity greater than 10
36
cm
−2
s
−1 with ...moderate beam currents and a reduced center of mass boost with respect to earlier B-Factories. An improved vertex resolution is required for precise time-dependent measurements and the SuperB Silicon Vertex Tracker will be equipped with an innermost layer of small radius (about 1.5
cm), resolution of
10
–
15
μ
m
in both coordinates, low material budget (
<
1
%
X0), and able to withstand a background rate of several tens of MHz/cm
2. The ambitious goal of designing a thin pixel device with these stringent requirements is being pursued with specific R&D programs on different technologies: hybrid pixels, CMOS MAPS and pixel sensors developed with vertical integration technology. The latest results on the various pixel options for the SuperB SVT will be presented.
A new generation of high-resolution hypernuclear γ-spectroscopy experiments using high-purity germanium (HPGe) detectors is presently designed for the FINUDA spectrometer at DAΦNE, the Frascati ...Φ-factory, and for PANDA, the p–p¯ hadron spectrometer at the future FAIR facility. In both spectrometers the HPGe detectors have to be operated in strong magnetic fields. In this paper we report on a series of measurements performed on a HPGe detector inserted in a magnetic field of intensity up to 2.5T, the highest ever reached for operations with a HPGe, and with different orientations of the detector's axis with respect to field direction. A significant worsening of the energy resolution was found, but with a moderate loss of the efficiency. The most relevant features of the peak shapes, described by bi-Gaussian functions, are parametrized in terms of field intensity and energy: this allows to correct the spectra measured in magnetic field and to recover the energy resolution almost completely.
The superB silicon vertex tracker Rizzo, G.; Avanzini, C.; Batignani, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2010, Letnik:
617, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The SuperB asymmetric
e
+
–
e
-
collider has been designed to deliver a luminosity greater than
10
36
cm
-
2
s
-
1
with moderate beam currents. Comparing to current B-Factories, the reduced center of ...mass boost of the SuperB machine requires improved vertex resolution to allow precision measurements sensitive to New Physics. We present the conceptual design of the silicon vertex tracker (SVT) for the SuperB detector with the present status of the R&D on the different options under study for its innermost Layer0.
In September 2008 the SLIM5 collaboration submitted a low material budget silicon demonstrator to test with 12
GeV/
c protons, at the PS-T9 test-beam at CERN. Two different detectors were placed as ...DUTs inside a high-resolution and fast-readout beam telescope. The first DUT was a high resistivity double sided silicon detector, with short strips (“striplets”) and with reduced thickness, at
45
∘
angle to the detector's edge, readout by the data-driven FSSR2 chip. The other one was a 4k-Pixel Matrix of Deep N Well MAPS, developed in a 130
nm CMOS Technology, providing digital sparsified readout. In the following, I present the striplets and also the beam telescope characteristics, with some details about the frontend readout (based on the FSSR2 chip) and some preliminary results of the data-analysis.
Deep n-well MAPS in a 130 nm CMOS technology: Beam test results Lusiani, A; Manghisoni, M; Re, V ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2010, Letnik:
623, Številka:
1
Journal Article
Recenzirano
We report on recent beam test results for the APSEL4D chip, a new deep n-well MAPS prototype with a full in-pixel signal processing chain obtained by exploiting the triple well option of the CMOS ...inline image process. The APSEL4D chip consists of a 4096 pixel matrix (32 rows and 128 columns) with inline image pixel cell area, with custom readout architecture capable of performing data sparsification at pixel level. APSEL4D has been characterized in terms of charge collection efficiency and intrinsic spatial resolution under different conditions of discriminator threshold settings using a 12 GeV/c proton beam in the T9 area of the CERN PS. We observe a maximum hit efficiency of 92% and we estimate an intrinsic resolution of about inline image. The data driven approach of the tracking detector readout chips has been successfully used to demonstrate the possibility to build a Level 1 trigger system based on associative memories. The analysis of the beam test data is critically reviewed along with the characterization of the device under test.
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