109713979
Link model simulation and power penalty specification of the versatile link systems
This paper presents simulation and experimental studies of optical power penalties on the Versatile Link, a common R&D project on high-speed optical link for SLHC experiments. The 10 Gigabit Ethernet (10GbE) link model is examined and conservative link power penalties are predicted. We conduct parameter sensitivity analyses and find that the transmitter characteristics affect the link power penalties most. Power penalty differences of multi-mode and single-mode commerical transceiver modules over different fiber lengths are tested to be within the simulation limits. The optical power budgets are then proposed for different Versatile Link variants.
121725222
Optical links for ATLAS liquid argon calorimeter front-end electronics readout
We present the optical data links for the ATLAS liquid argon calorimeter. The current status of the vertical cavity surface emitting laser failures, the up-to-date results in searching for the failure cause, experiences gained in the searching process, possible backup plans for the optical transmitters and the lessons learned are also discussed.
6496614
Response of a 0.25 μm thin-film silicon-on-sapphire CMOS technology to total ionizing dose
The radiation response of a 0.25 μm silicon-on-sapphire CMOS technology is characterized at the transistor and circuit levels utilizing both standard and enclosed layout devices. The threshold-voltage shift is less than 170 mV and the leakage-current increase is less than 1 nA for individual standard-layout nMOSFET and pMOSFET devices at a total dose of 100 krad(SiO2). The increase in power supply current at the circuit level was less than 5%, consistent with the small change in off-state transistor leakage current. The technology exhibits good characteristics for use in the electronics of the ATLAS experiment at the Large Hadron Collider.
55746504
The versatile link, a common project for super-LHC
A common project to develop a bi-directional, radiation tolerant, high speed (4.8 Gb/s) optical link for future high energy physics experiments is described. Due to be completed in 2012, it targets the upgrade programs of detectors installed at CERN's Large Hadron Collider (LHC). The development of radiation and magnetic field tolerant opto-electronic devices, fibre and connectors is described. Both Single-Mode and Multi-Mode versions of the system operating respectively at 850 nm and 1310 nm wavelength are proposed. First results at component and system level are presented, based mostly on commercially available devices.
15092713
A serializer ASIC for high speed data transmission in cryogenic and HiRel environment
A high speed 16:1 serializer ASIC has been developed using a commercial 0.25 μm silicon-on-sapphire CMOS technology. At room temperature the ASIC operates from 4.0 to 5.7 Gbps with power consumption of 463 mW. The total jitter is 62 ps at the bit error rate of 10−12 at 5 Gbps. A 200-MeV proton beam test indicates that the ASIC is suitable for high energy physics applications. A liquid nitrogen temperature test indicates that the ASIC may be used at cryogenic temperature applications. The reliability of the serializer at liquid nitrogen temperature is to be studied. A 6-lane serializer array with 10 Gbps/lane with redundancy capability is under development.
110567078
ASIC developments for high speed serial data transmission in particle physics experiments
Abstract We report R&D results on two integrated circuit designs: a 5 Gbps 16:1 serializer and a 5 GHz LC phase-locked-loop (PLL). The prototypes were fabricated with a commercial thin-film silicon-on-sapphire 0.25 μm CMOS technology. Both the serializer and the PLL have been evaluated to meet design goals and tested against operation conditions in the environment of a particle physics detector front-end for the proposed HL-LHC upgrade.
55543374
Supersymmetric subelectroweak scale dark matter, the Galactic Center gamma-ray excess, and exotic decays of the 125 GeV Higgs boson
We continue our exploration of the nearly Peccei-Quinn symmetric limit shared by common singlet extensions of the Minimal Supersymmetric Standard Model. This limit has been established as a viable framework for studying sub-electroweak scale dark matter phenomenology and has interesting and direct connections to new exotic Higgs decay physics. We present analytic calculations to motivate the important phenomenological features mentioned above. We also discuss benchmark points in this model framework that accommodate the observed Galactic Center gamma ray excess. We emphasize connections between phenomenology of dark matter direct detection and indirect detection, and new exotic decay channels for the 125 GeV Higgs boson. We conclude by identifying two benchmark modes of exotic Higgs decays for h ! + 6ET and h ! b b6ET nal states and estimate their sensitivity prospects at the LHC.
119209516
Polarized view of the top asymmetry
Recent experimental results from the CDF collaboration which study the top forward-backward asymmetry have strengthened the case that new physics is playing a role in $t\overline{t}$ production. Here, we propose a set of measurements, built from the charged lepton kinematics in semileptonic and fully leptonic $t\overline{t}$ events, designed to further probe the underlying causes of this asymmetry both at the Tevatron and at the LHC. Using a set of conservative reference models, we find that measurements of the charged lepton asymmetry, top polarization, and $t\overline{t}$ spin correlation can establish the existence of new physics and distinguish between competing models both at the Tevatron and the LHC. At the Tevatron, discrimination between models is possible at the $3\ensuremath{\sigma}$ level. At the LHC, we demonstrate that a top forward-backward asymmetry can be established at $\ensuremath{\gtrsim}3\ensuremath{\sigma}$ in the first $\ensuremath{\sim}5\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of data and show how competing explanations can be further disentangled.
119232315
Quark orbital motions from Wigner distributions
We investigate quark Wigner distributions in a light-cone spectator model. Both the scalar and the axial-vector spectators are included. The light-cone wave functions are derived from effective quark-spectator-nucleon vertex and then generalized by adjusting the power of energy denominators. The gauge link is taken into account by introducing relative phases to the light-cone amplitudes, and the phases are estimated from one gluon exchange interactions. The mixing distributions, which describe the correlation between transverse coordinate and transverse momentum and represent quark orbital motions, are calculated from the Wigner distributions. We find both $u$ quark and $d$ quark have positive orbital angular momentum in a polarized proton at small $x$ region, but a sign change is observed at large $x$ region for the $d$ quark. Besides, some model relations between Wigner distributions with different polarization configurations are found.
17752635
Quasi-supersymmetric G3 unification from intersecting D6-branes on Type IIA orientifolds
Abstract We construct three quasi-supersymmetric G 3 GUT models with S 3 symmetry and gauge coupling unification from intersecting D6-branes on Type IIA orientifolds. The Standard Model fermions and Higgs doublets can be embedded into the bifundamental representations in these models, and there is no any other unnecessary massless representation. Especially in Model I with gauge group U (4) 3 , we just have three-family SM fermions and three pairs of Higgs particles. The G 3 gauge symmetry in these models can be broken down to the Standard Model gauge symmetry by introducing light open string states. And 1 TeV scale supersymmetry breaking soft masses imply the reasonable intermediate string scale.
53310241
COSMOGENIC TAU NEUTRINO INDUCED RADIO EMISSION
Cosmogenic neutrinos1 are expected from ultrahigh energy cosmic rays undergoing the GZK process2,3 and anticipated to be observed by detection of the air showers from the decays of tau leptons. We use CORSIKA simulated shower structure to Calculate the coherent geosynchrotron radio emissions of the tau decay showers above 1017 eV. We present the pattern and spectrum of the radio waves and discuss their detections by radio antennae.