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.
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.
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.
118652336
Determination of the neutrino flavor ratio at the astrophysical source
We discuss the reconstruction of neutrino flavor ratios at astrophysical sources through the future neutrino-telescope measurements. Taking the ranges of neutrino mixing parameters ${\ensuremath{\theta}}_{ij}$ as those given by the current global fit, we demonstrate by a statistical method that the accuracies in the measurements of energy-independent ratios $R\ensuremath{\equiv}\ensuremath{\phi}({\ensuremath{\nu}}_{\ensuremath{\mu}})/(\ensuremath{\phi}({\ensuremath{\nu}}_{e})+\ensuremath{\phi}({\ensuremath{\nu}}_{\ensuremath{\tau}}))$ and $S\ensuremath{\equiv}\ensuremath{\phi}({\ensuremath{\nu}}_{e})/\ensuremath{\phi}({\ensuremath{\nu}}_{\ensuremath{\tau}})$ among integrated neutrino flux should both be better than 10% in order to distinguish between the pion source and the muon-damped source at the $3\ensuremath{\sigma}$ level. The 10% accuracy needed for measuring $R$ and $S$ requires an improved understanding of the background atmospheric neutrino flux to a better than 10% level in the future. We discuss the applicability of our analysis to practical situations that the diffuse astrophysical neutrino flux arises from different types of sources and each point source has a neutrino flavor ratio varying with energies. We also discuss the effect of the leptonic $CP$ phase on the flavor-ratio reconstruction.
30481535
A compact apparatus for muon lifetime measurement and time dilation demonstration in the undergraduate laboratory
We describe a compact apparatus for measuring the charge-averaged lifetime of atmospheric muons in plastic scintillator using low-cost, low-power electronics. We present measurements of the stopping rate of atmospheric muons as a function of altitude to demonstrate relativistic time dilation. The apparatus is designed for the advanced undergraduate physics laboratory and is suitable for field measurements.