A
bstract
We describe a proposal to add a set of very forward detectors to the CMS experiment for the high-luminosity era of the Large Hadron Collider to search for beyond the standard model ...long-lived particles, such as dark photons, heavy neutral leptons, axion-like particles, and dark Higgs bosons. The proposed subsystem is called
FACET
for
F
orward-
A
perture
C
MS
E
x
T
ension, and will be sensitive to any particles that can penetrate at least 50 m of magnetized iron and decay in an 18 m long, 1 m diameter vacuum pipe. The decay products will be measured in detectors using identical technology to the planned CMS Phase-2 upgrade.
Little is known about the diagnostic validity of the 15‐item Geriatric Depression Scale ‐ Short Form (GDS‐SF), especially when compared to the original 30‐item version (Geriatric Depression Scale ‐ ...Long Form; GDS‐LF). This study compared the GDS‐SF and GDS‐LF with a sample of depressed, demented, and thought‐disordered inpatients. The GDS‐SF and GDS‐LF were found to be highly correlated (r = .89) and to have similar high sensitivity rates. The specificity rates for both forms were similar, but lower than desirable. Overall, the GDS‐SF was found to be an adequate substitute for the GDS‐LF.
The CDF Silicon Vertex Trigger Ashmanskas, Bill; Barchiesi, A.; Bardi, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2004, Letnik:
518, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The Collider Detector at Fermilab (CDF) experiment's Silicon Vertex Trigger (SVT) is a system of 150 custom 9U VME boards that reconstructs axial tracks in the CDF silicon strip detector in a
15
μs
...pipeline. SVT's
35
μm
impact parameter resolution enables CDF's Level 2 trigger to distinguish primary and secondary particles, and hence to collect large samples of hadronic bottom and charm decays. We review some of SVT's key design features. Speed is achieved with custom VLSI pattern recognition, linearized track fitting, pipelining, and parallel processing. Testing and reliability are aided by built-in logic state analysis and test-data sourcing at each board's input and output, a common interboard data link, and a universal “Merger” board for data fan-in/fan-out. Speed and adaptability are enhanced by use of modern FPGAs.
B, D and K decays Buchalla, G.; Komatsubara, T. K.; Muheim, F. ...
European physical journal. C, Particles and fields (Print),
09/2008, Letnik:
57, Številka:
1-2
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
The present report documents the results of Working Group 2:
B
,
D
and
K
decays, of the workshop on Flavor in the Era of the LHC, held at CERN from November 2005 through March 2007.
With the advent ...of the LHC, we will be able to probe New Physics (NP) up to energy scales almost one order of magnitude larger than it has been possible with present accelerator facilities. While direct detection of new particles will be the main avenue to establish the presence of NP at the LHC, indirect searches will provide precious complementary information, since most probably it will not be possible to measure the full spectrum of new particles and their couplings through direct production. In particular, precision measurements and computations in the realm of flavor physics are expected to play a key role in constraining the unknown parameters of the Lagrangian of any NP model emerging from direct searches at the LHC.
The aim of Working Group 2 was twofold: on the one hand, to provide a coherent up-to-date picture of the status of flavor physics before the start of the LHC; on the other hand, to initiate activities on the path towards integrating information on NP from high-
p
T
and flavor data.
This report is organized as follows: in Sect. 1, we give an overview of NP models, focusing on a few examples that have been discussed in some detail during the workshop, with a short description of the available computational tools for flavor observables in NP models. Section 2 contains a concise discussion of the main theoretical problem in flavor physics: the evaluation of the relevant hadronic matrix elements for weak decays. Section 3 contains a detailed discussion of NP effects in a set of flavor observables that we identified as “benchmark channels” for NP searches. The experimental prospects for flavor physics at future facilities are discussed in Sect. 4. Finally, Sect. 5 contains some assessments on the work done at the workshop and the prospects for future developments.
Silicon vertex tracker: a fast precise tracking trigger for CDF Ashmanskas, W; Bardi, A; Bari, M ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2000, Letnik:
447, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The Silicon Vertex Tracker (SVT), currently being built for the CDF II experiment, is a hardware device that reconstructs 2-D tracks online using measurements from the Silicon Vertex Detector (SVXII) ...and the Central Outer Tracker (COT). The precise measurement of the impact parameter of the SVT tracks will allow, for the first time in a hadron collider environment, to trigger on events containing B hadrons that are very important for many studies, such as CP violation in the b sector and searching for new heavy particles decaying to b
b
̄
. In this report we describe the overall architecture, algorithms and the hardware implementation of the SVT.
The CDF online Silicon Vertex Tracker Ashmanskas, W.; Bardi, A.; Bari, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2002, Letnik:
485, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The CDF Online Silicon Vertex Tracker (SVT) reconstructs 2D tracks by linking hit positions measured by the Silicon Vertex Detector to the Central Outer Chamber tracks found by the eXtremely Fast ...Tracker (XFT). The system has been completely built and assembled and it is now being commissioned using the first CDF run II data. The precision measurement of the track impact parameter will allow triggering on B hadron decay vertices and thus investigating important areas in the B sector, like CP violation and B
s mixing. In this paper we briefly review the architecture and the tracking algorithms implemented in the SVT and we report on the performance of the system achieved in the early phase of CDF run II.
SVT: an online Silicon Vertex Tracker for the CDF upgrade Bardi, A.; Belforte, S.; Berryhill, J. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/1998, Letnik:
409, Številka:
1-3
Journal Article
Recenzirano
Odprti dostop
The SVT is an online tracker for the CDF upgrade which will reconstruct 2D tracks using information from the Silicon VerteX detector (SVXII) and Central Outer Tracker (COT). The precision measurement ...of the track impact parameter will then be used to select and record large samples of B hadrons. We discuss the overall architecture, algorithms, and hardware implementation of the system.
Initial experience with the CDF SVT trigger Ashmanskas, B.; Barchiesi, A.; Bardi, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2003, Letnik:
501, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The Collider Detector at Fermilab (CDF) Silicon Vertex Tracker (SVT) is a device that works inside the CDF Level 2 trigger to find and fit tracks in real time using the central silicon vertex ...detector information. SVT starts from tracks found by the Level 1 central chamber fast trigger and adds the silicon information to compute transverse track parameters with offline quality in about
15
μs
. The CDF SVT is fully installed and functional and has been exercised with real data during the spring and summer 2001. It is a complex digital device of more than 100 VME boards that performs a dramatic data reduction (only about one event in a thousand is accepted by the trigger). Diagnosing rare failures poses a special challenge and SVT internal data flow is monitored by dedicated hardware and software. This paper briefly covers the SVT architecture and design and reports on the SVT building/commissioning experience (hardware and software) and on the first results from the initial running.
The online silicon vertex tracker (SVT) is the new trigger processor dedicated to the two-dimensional (2-D) reconstruction of charged particle trajectories at the Level 2 of the Collider Detector at ...Fermilab (CDF) trigger. The SVT links the digitized pulse heights found within the silicon vertex detector to the tracks reconstructed in the central outer tracker by the Level 1 fast-track finder. Preliminary tests of the system took place during the October 2000 commissioning run of the Tevatron Collider. During the April-October 2001 data taking, it was possible to evaluate the performance of the system. In this paper, we review the tracking algorithms implemented in the SVT and we report on the performance achieved during the early phase of run II.
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