| 1. |
- Almehed, Sverker, et al.
(författare)
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Regional research exploitation of the LHC: A case-study of the required computing resources
- 2002
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Ingår i: Computer Physics Communications. - 0010-4655. ; 145:3, s. 341-350
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Tidskriftsartikel (refereegranskat)abstract
- A simulation study to evaluate the required computing resources for a research exploitation of the Large Hadron Collider (LHC) has been performed. The evaluation,vas done as a case study. assuming existence of a Nordic regional centre and using the requirements for per-forming a specific physics analysis as a yard-stick. Other input parameters were: assumption for the distribution of researchers at the institutions involved, an analysis model, and two different functional structures of the computing resources.
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| 2. |
- Anghinolfi, Francisco, et al.
(författare)
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DTMROC-S: Deep submicron version of the readout chip for the TRT detector in ATLAS
- 2002
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Ingår i: 8th Workshop On Electronics For LHC Experiments. ; , s. 95-99
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Konferensbidrag (refereegranskat)abstract
- A new version of the circuit for the readout of the ATLAS straw tube detector, TRT [1], has been developed in a deep-submicron process. The DTMROC-S is fabricated in a commercial 0.25μm CMOS IBM technology, with a library hardened by layout techniques [2]. Compared to the previous version of the chip [3] done in a 0.8μm radiation-hard CMOS and despite of the features added for improving the robustness and testability of the circuit, the deep-submicron technology results in a much smaller chip size that increases the production yield and lowers the power consumption.
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| 3. |
- Capeans, M., et al.
(författare)
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Recent aging studies for the ATLAS transition radiation tracker
- 2004
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Ingår i: IEEE Transactions on Nuclear Science. ; 51, s. 960-967
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Konferensbidrag (refereegranskat)abstract
- The transition radiation tracker (TRT) is one of the three subsystems of the inner detector of the ATLAS experiment. It is designed to operate for 10 yr at the LHC, with integrated charges of /spl sim/10 C/cm of wire and radiation doses of about 10 Mrad and 2/spl times/10/sup 14/ neutrons/cm/sup 2/. These doses translate into unprecedented ionization currents and integrated charges for a large-scale gaseous detector. This paper describes studies leading to the adoption of a new ionization gas regime for the ATLAS TRT. In this new regime, the primary gas mixture is 70%Xe-27%CO/sub 2/-3%O/sub 2/. It is planned to occasionally flush and operate the TRT detector with an Ar-based ternary mixture, containing a small percentage of CF/sub 4/, to remove, if needed, silicon pollution from the anode wires. This procedure has been validated in realistic conditions and would require a few days of dedicated operation. This paper covers both performance and aging studies with the new TRT gas mixture.
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| 4. |
- Chang, CH, et al.
(författare)
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BCVEGPY: an event generator for hadronic production of the B-c meson
- 2004
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Ingår i: Computer Physics Communications. - : Elsevier BV. - 0010-4655. ; 159:3, s. 192-224
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Tidskriftsartikel (refereegranskat)abstract
- We have written a Fortran program BCVEGPY, which is an event generator for the hadronic production of the B-c meson through the dominant hard subprocess gg --> B-c(B-c(*)) + b + c. To achieve a compact program, we have written the amplitude of the subprocess with the particle helicity technique and made it as symmetric as possible, by decomposing the gluon self couplings and then applying the symmetries. To check the program, various cross sections of the subprocess have been computed numerically and compared with those in the literature. BCVEGPY is written in a PYTHIA-compatible format, thus it is easy to implement in PYTHIA.
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| 5. |
- Driouichi, Chafik, et al.
(författare)
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Observation potential of the decays B0s,d → J/ψη
- 2002
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Ingår i: EPJ direct. - 1435-3725. ; 4:CN2, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- The observation potential of the decays B0s,d → J/ψη with the ATLAS detector at the LHC is described in this paper. At present there exist only upper limits for the branching fractions, but at LHC, a clear signal for the decay mode B0s,d → J/ψη is expected. The branching fraction of this decay mode can thus be measured, and other parameters such as B0s lifetime can be measured as well. The decay mode B0s → J/ψη is analogous to the mode B0s → J/ψφ, which has been studied extensively in view of CP violation measurements. In these two decay modes, the CP asymmetry predicted by the Standard Model is very small, and the observation of a sizeable effect would be a signal of physics beyond the Standard Model. The decay mode J/ψη constitutes thus a cross-check for the mode J/ψφ. Furthermore, the former final state is a CP-eigenstate and no angular analysis is thus needed. The reconstruction of η-mesons at LHC experiments has not been addressed before, and therefore the study presented here can also be regarded as an example of the physics prospects with η-mesons at the LHC.
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| 6. |
- Eerola, Paula
(författare)
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ATLAS B physics performance update
- 2004
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Ingår i: AIP Conference Proceedings. - : AIP. - 1551-7616 .- 0094-243X. ; 722, s. 242-248
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Konferensbidrag (refereegranskat)abstract
- An update of the B physics performance of the ATLAS experiment is presented. After a short review of B production and decays at LHC, the main features of the ATLAS detector are described, and the present construction status is shown. Physics topics which are presented are: precision measurements, rare decays, and B production. It is shown that despite of recent changes in the trigger strategy and initial detector layout, ATLAS retains an excellent potential for measurements of sin2β and rare dimuon decays. A large spectrum of B physics studies is also feasible - here we present examples of precision measurements with Bs0 mesons, Bc mesons, and B production
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| 7. |
- Eerola, Paula, et al.
(författare)
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Atlas Data-Challenge 1 on NorduGrid
- 2003
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Konferensbidrag (refereegranskat)abstract
- The first LHC application ever to be executed in a computational Grid environment is the so-called ATLAS Data-Challenge 1, more specifically, the part assigned to the Scandinavian members of the ATLAS Collaboration. Taking advantage of the NorduGrid testbed and tools, physicists from Denmark, Norway and Sweden were able to participate in the overall exercise starting in July 2002 and continuing through the rest of 2002 and the first part of 2003 using solely the NorduGrid environment. This allowed to distribute input data over a wide area, and rely on the NorduGrid resource discovery mechanism to find an optimal cluster for job submission. During the whole Data-Challenge 1, more than 2 TB of input data was processed and more than 2.5 TB of output data was produced by more than 4750 Grid jobs.
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| 8. |
- Eerola, Paula, et al.
(författare)
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Atlas Data-Challenge 1 on NorduGrid
- 2003
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Ingår i: Proceedings of CHEP 2003.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The first LHC application ever to be executed in a computational Grid environment is the so-called ATLAS Data-Challenge 1, more specifically, the part assigned to the Scandinavian members of the ATLAS Collaboration. Taking advantage of the NorduGrid testb
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| 9. |
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| 10. |
- Eerola, Paula, et al.
(författare)
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Building a Production Grid in Scandinavia
- 2003
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Ingår i: IEEE Internet Computing. - : IEEE. ; 7:4, s. 27-35
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The aim of the NorduGrid project is to build and operate a production grid infrastructure in Scandinavia and Finland. By developing innovative middleware solutions, it enables a 24/7 production-level test bed. Through a common access layer, NorduGrid conn
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