Recent results from HERA Tokushuku, K.
Nuclear physics. A,
08/1998, Letnik:
638, Številka:
1
Journal Article
Recenzirano
Recent measurements from HERA collider experiments at DESY were presented. The talk includes measurements of the proton structure functions in a wide kinematic region in
Q
2 and
x, extractions of the ...gluon distribution in the proton from various processes and heavy quark productions. The results are compared with models based on the perturbative quantum chromodynamics (pQCD).
Small x physics at HERA Tokushuku, K.
Nuclear physics. A,
02/1998, Letnik:
629, Številka:
1
Journal Article
Recenzirano
Recent measurements of the structure function
F
2 in
e
+p
scattering at HERA were presented for a wide range of
Q
2
and
x. The rapid rise of
F
2 with decreasing
x has been confirmed with high ...statistical data obtained in 1994. In the measurements, the
Q
2 range was extended down to 1.5GeV
2. The rise corresponds to the rapid increase of the total virtual photon-proton cross section at high energies. On the other hand, the total cross section of photon-proton interaction at
Q
2 = 0 has no strong energy dependence. H1 and ZEUS performed new
F
2 measurements for
Q
2 < 1GeV
2 with upgraded detectors in order to study the transition region. The results were shown and compared to predictions of various models.
The ATLAS Muon Trigger "Slice" Sidoti, A.; Bellomo, M.; Biglietti, M. ...
IEEE transactions on nuclear science,
02/2008, Letnik:
55, Številka:
1
Journal Article
Recenzirano
The ATLAS experiment at the Large Hadron Collider (LHC) will face the challenge of selecting interesting candidate events in proton-proton collisions at 14 TeV center of mass energy, while rejecting ...the enormous number of background events. The trigger system architecture is organized in three levels. From a bunch crossing rate of 40 MHz, the First Level trigger, hardware implemented, will reduce this rate to around ~75 kHz. Then the software based High Level Trigger (HLT), composed by the Second Level Trigger and the Event Filter reduces the rate to 200 Hz. In this paper, we will present the implementation of the muon trigger ldquoslice,rdquo signal efficiencies, background rejection rates, and system performances (execution time, memory consumption, etc.) for online muon selection based on Monte Carlo simulations and results obtained on real events collected during cosmic data taking runs.
Analog readout modules for the ZEUS microvertex detector Fusayasu, T.; Tokushuku, K.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/1999, Letnik:
436, Številka:
1
Journal Article
Recenzirano
Analog readout modules have been developed for a silicon microvertex detector of the electron–proton collision experiment ZEUS. Analog signals kept in the front end are read out and digitized by ADCs ...and processed afterwards to reduce the data volume while keeping the signal information. We have developed prototype modules with 10-bit 10
MHz ADCs and digital processors built in Field Programmable Gate Arrays. Their performance was investigated.
Production of exclusive dijets in diffractive deep inelastic Formula omitted scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 372 pb Formula omitted. The ...measurement was performed for Formula omitted-p centre-of-mass energies in the range Formula omitted and for photon virtualities Formula omitted. Energy flows around the jet axis are presented. The cross section is presented as a function of Formula omitted and Formula omitted, where Formula omitted, x is the Bjorken variable and Formula omitted is the proton fractional longitudinal momentum loss. The angle Formula omitted is defined by the Formula omitted-dijet plane and the Formula omitted- Formula omitted plane in the rest frame of the diffractive final state. The Formula omitted cross section is measured in bins of Formula omitted. The results are compared to predictions from models based on different assumptions about the nature of the diffractive exchange.
A Forward Plug Calorimeter (FPC) for the ZEUS detector at HERA has been built as a shashlik lead–scintillator calorimeter with wave length shifter fiber readout. Before installation it was tested and ...calibrated using the X5 test beam facility of the SPS accelerator at CERN. Electron, muon and pion beams in the momentum range of 10–100 GeV/
c were used. Results of these measurements are presented as well as a calibration monitoring system based on a
60Co source.
The design and performance of the ZEUS micro vertex detector Polini, A.; Brock, I.; Goers, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2007, Letnik:
581, Številka:
3
Journal Article
Recenzirano
Odprti dostop
In order to extend the tracking acceptance, to improve the primary and secondary vertex reconstruction and thus enhancing the tagging capabilities for short lived particles, the ZEUS experiment at ...the HERA Collider at DESY installed a silicon strip vertex detector. The barrel part of the detector is a 63
cm long cylinder with silicon sensors arranged around an elliptical beampipe. The forward part consists of four circular shaped disks. In total just over 200k channels are read out using
2.9
m
2
of silicon. In this report a detailed overview of the design and construction of the detector is given and the performance of the completed system is reviewed.
The trigger of the ZEUS experiment at HERA is based on a dead-time free, pipelined first level processor, a transputer network second level and a traditional computer farm at the third level. The ...environment at HERA, with a fast (96 ns) bunch crossing repetition rate and a high hadronic background, anticipates much more extreme conditions than the LHC experiments will face. We describe the design strategies and the results of ZEUS, with emphasis on the flexibility of the system that allowed us to satisfy the physics requirements that changed with increasing luminosity.
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