111231338
Update on the high speed serializer ASIC development for ATLAS Liquid Argon calorimeter upgrade
We have been developing a serializer application-specific integrated circuit (ASIC) based on a commercial 0.25-μm silicon-on-sapphire (SOS) CMOS technology for the ATLAS liquid argon calorimeter front-end electronics upgrade. The first prototype, a 5 Gbps 16:1 serializer has been designed, fabricated, and tested in lab environment and in a 200 MeV proton beam. The test results indicate that the first prototype meets the design goals. The second prototype, a double-lane, 8 Gbps per lane serializer is under development. The post-layout simulation indicates that 8 Gbps is achievable. In this paper we present the design and the test results of the first prototype and the design and status of the second prototype.
122670904
The design of 8-Gbps VCSEL drivers for ATLAS liquid Argon calorimeter upgrade
We present designs and preliminary test results of LOCld1 and LOCld4, VCSEL drivers in a commercial 0.25-mu m m Silicon-on-Sapphire (SoS) CMOS process for ATLAS liquid Argon calorimeter upgrade. Active shunt peaking, multiple-stage amplification and higher voltage supply are used to achieve the data rate of 8 Gbps. LOCld1 is a single channel VCSEL driver with a differential output, while LOCld4 has four channels with single-ended open-drain outputs. Both drivers have tunable modulation and peaking strength. Bias current for VCSEL is also embedded.
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.
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.
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.
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.
44596378
Unraveling the physics behind modified Higgs couplings: LHC versus a Higgs factory
Strongly modified $h\ensuremath{\gamma}\ensuremath{\gamma}$ and $hgg$ couplings indicate new electroweak and color mediators, respectively, with a light mass and a significant coupling to the Higgs boson. We point out the Higgs boson could have a significant decay width into the mediators. This represents one new class of exotic Higgs decay possibilities: off-shell exotic Higgs decays. We then propose uncovering the hidden new physics through such exotic decays. A great advantage of this strategy is that we can directly probe the couplings between the Higgs boson and the mediators, which is hard to achieve by using other methods. Focusing on the electroweak mediators, we study a simplified model using as an example final states with tau leptons and neutrinos. Because one of the mediators is off shell and its decay products are extremely soft, it is challenging to make a discovery at the Large Hadron Collider. A Higgs factory such as the International Linear Collider, however, could serve as a discovery machine for such exotic Higgs decays even in an early stage.
118915813
Supersymmetric Pati–Salam models from intersecting D6-branes: a road to the Standard Model
Abstract We provide a systematic construction of three-family N = 1 supersymmetric Pati–Salam models from Type IIA orientifolds on T 6 / ( Z 2 × Z 2 ) with intersecting D6-branes. All the gauge symmetry factors SU ( 4 ) C × SU ( 2 ) L × SU ( 2 ) R arise from the stacks of D6-branes with U ( n ) gauge symmetries, while the “hidden sector” is specified by USp ( n ) branes, parallel with the orientifold planes or their Z 2 images. The Pati–Salam gauge symmetry can be broken down to the SU ( 3 ) C × SU ( 2 ) L × U ( 1 ) B − L × U ( 1 ) I 3 R via D6-brane splittings, and further down to the Standard Model via D- and F-flatness preserving Higgs mechanism from massless open string states in a N = 2 subsector. The models also possess at least two confining hidden gauge sectors, where gaugino condensation can in turn trigger supersymmetry breaking and (some) moduli stabilization. The systematic search yields 11 inequivalent models: 8 models with less than 9 Standard Model Higgs doublet-pairs and 1 model with only 2 Standard Model Higgs doublet-pairs, 2 models possess at the string scale the gauge coupling unification of SU ( 2 ) L and SU ( 2 ) R , and all the models possess additional exotic matters. We also make preliminary comments on phenomenological implications of these models.
122901102
LABORATORY ASTROPHYSICS IN TAIWAN
We report the development of laboratory astrophysics program in Taiwan. We begin with outlining Taiwan's participation in the FLASH collaboration for measuring the fluorescence yield using SLAC 28.5 GeV electron beam. We then report the domestic effort of studying cosmic ray shower properties using NSRRC 1.5 GeV electron beam.
13116555
Simulation of the cosmic ray tau neutrino telescope (CRTNT) experiment
A τ lepton can be produced in a charged current interaction by a cosmic ray tau neutrino with material inside a mountain. If it escapes from the mountain, it will decay and initiate a shower in the air, which can be detected by an air shower fluorescence/Cherenkov light detector. Designed according to such a principle, the cosmic ray tau neutrino telescope (CRTNT) experiment, located at the foothill of Mt Balikun in Xinjiang, China, will search for very high-energy cosmic τ neutrinos from energetic astrophysical sources by detecting those showers. This paper describes a Monte Carlo simulation for a detection of τ events by the CRTNT experiment. Ultra-high-energy cosmic ray events are also simulated to estimate the potential contamination. With the CRTNT experiment composed of four detector stations, each covering 64 ◦ × 14 ◦ field of view, the expected event rates are 28.6, 21.9 and 4.7 per year assuming an AGN neutrino flux according to Semikoz and Sigl (2004 J. Cosmol. Astropart. Phys. JCAP 04(2004)003), Mannheim–Protheroe–Rachen (MPR) active galactic nucleus (AGN) jet model and Stecker–Done–Salamon–Sommers (SDSS) AGN core model, respectively. Null detection of such a τ event by the CRTNT experiment in 1 year could set a 90% C.L. upper limit on 19.9 (eV cm −2 s −1 sr −1 ) for an E −2 neutrino spectrum.
118316245
Exotic Higgs Decay h to 2a at the International Linear Collider: a Snowmass White Paper
A Higgs factory like the International Linear Collider (ILC) can play a significant role in searching for exotic decays of Higgs bosons. As an illustration, we investigate the ILC sensitivity for the decay topology $h\to a_1 a_1 \to \tau\bar \tau\tau \bar \tau$ in the Next-to-Minimal-Supersymmetric-Standard-Model (NMSSM). Here $h$ can be either Standard-Model-like or non-standard, and $a_{1}$ is the lightest CP-odd Higgs boson. We also compare results to expectations for this channel at the LHC.