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Special Section Guest Editorial: Detectors for Astronomy and Cosmology
This guest editorial summarizes the Special Section on Detectors for Astronomy and Cosmology
Higgs boson hadronic branching ratios at the ILC
We present a study of the Higgs boson decay branching ratios to ,
and gluons, one of the cornerstones of the physics program at the
International Linear Collider (ILC). A standard model Higgs boson of 120\,GeV
mass, produced in the Higgs-strahlung process at \,GeV was
investigated using the full detector simulation and reconstruction procedures.
The analysis was performed in the framework of the Silicon Detector (SiD)
concept with full account of inclusive standard model backgrounds. The selected
decay modes contained two heavy flavour jets in the final state and required
excellent flavour tagging through precise reconstruction of interaction and
decay vertices in the detector. A new signal discrimination technique using
correlations of neural network outputs was used to determine the branching
ratios and estimate their uncertainties, 4.8\%, 8.4\% and 12.2\% for
, and gluons respectively.Comment: 9 Pages, 5 figures and 5 table
Micromotion-Synchronized Pulsed Doppler Cooling of Trapped Ions
We propose and demonstrate a new method for Doppler cooling trapped-ion
crystals where the distribution of micromotion amplitudes may be large and
uneven. The technique uses pulses of Doppler cooling light synchronized with
the trap RF that selectively target ions when their velocity is near a node,
leading to more uniform cooling across a crystal by a single tone of cooling
light. We lay out a theoretical framework that describes where this technique
is practical, and provide a simple experimental demonstration
Evaporative CO2 cooling using microchannels etched in silicon for the future LHCb vertex detector
The extreme radiation dose received by vertex detectors at the Large Hadron
Collider dictates stringent requirements on their cooling systems. To be robust
against radiation damage, sensors should be maintained below -20 degree C and
at the same time, the considerable heat load generated in the readout chips and
the sensors must be removed. Evaporative CO2 cooling using microchannels etched
in a silicon plane in thermal contact with the readout chips is an attractive
option. In this paper, we present the first results of microchannel prototypes
with circulating, two-phase CO2 and compare them to simulations. We also
discuss a practical design of upgraded VELO detector for the LHCb experiment
employing this approach.Comment: 12 page
Two-photon amplitude interferometry for precision astrometry
Improved quantum sensing of photon wave-functions could provide high
resolution observations in the optical benefiting numerous fields, including
general relativity, dark matter studies, and cosmology. It has been recently
proposed that stations in optical interferometers would not require a
phase-stable optical link if instead sources of quantum-mechanically entangled
pairs could be provided to them, potentially enabling hitherto prohibitively
long baselines. A new refinement of this idea is developed, in which two
photons from different sources are interfered at two separate and decoupled
stations, requiring only a slow classical information link between them. We
rigorously calculate the observables and contrast this new interferometric
technique with the Hanbury Brown & Twiss intensity interferometry. We argue
this technique could allow robust high-precision measurements of the relative
astrometry of the two sources. A basic calculation suggests that angular
precision on the order of as could be achieved in a single night's
observation of two bright stars.Comment: 18 pages, 4 figures; submitted to Physical Review
ISIS2: Pixel Sensor with Local Charge Storage for ILC Vertex Detector
ISIS (In-situ Storage Imaging Sensor) is a novel CMOS sensor with multiple
charge storage capability developed for the ILC vertex detector by the Linear
Collider Flavour Identification (LCFI) collaboration. This paper reports test
results for ISIS2, the second generation of ISIS sensors implemented in a 0.18
micron CMOS process. The local charge storage and charge transfer were
unambiguously demonstrated.Comment: 11 pages, 16 figures, to be included in the Proceedings of
International Linear Collider Workshop 201
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