3,411 research outputs found
Mixing in the D0 system - Results from collider experiments
Mixing in the D0 system may provide a sensitive probe for new physics beyond
the Standard Model (SM) but has so far eluded experimental observation. The SM
predictions are typically small (< 10^{-3}) for the mixing parameters x, y
which, in the absence of charge-parity (CP) symmetry violation, measure the
mass (x= Delta(m)/Gamma) and lifetime (y= Delta(Gamma)/2Gamma) difference of
the CP eigenstates in the D0 system. The asymmetric B-factory experiments BABAR
and Belle open up the opportunity of measuring x, y with unprecedented
statistical precision and sample purities. Results from BABAR and Belle, and
from CLEO are reviewed.Comment: 28 pages, 7 figures, typos correcte
Scanning tunneling spectroscopy of superconducting LiFeAs single crystals: Evidence for two nodeless energy gaps and coupling to a bosonic mode
The superconducting compound, LiFeAs, is studied by scanning tunneling
microscopy and spectroscopy. A gap map of the unreconstructed surface indicates
a high degree of homogeneity in this system. Spectra at 2 K show two nodeless
superconducting gaps with meV and
meV. The gaps close as the temperature is increased to the bulk
indicating that the surface accurately represents the bulk. A dip-hump
structure is observed below with an energy scale consistent with a
magnetic resonance recently reported by inelastic neutron scattering
Estimated 2020 CO2 Emission Reductions in Virginia’s Transportation Sector from COVID-19
The initial lockdown phase of the COVID-19 pandemic presented an unfortunate opportunity to observe how abrupt, large-scale changes in traffic volume can reduce greenhouse gas emissions. This study explores how carbon dioxide (CO2) emissions from Virginia’s transportation sector may have been affected by the changes in activity stemming from COVID-19 to inform more carbon-neutral policies as the state recovers from the economic downfall. Emission savings were calculated by multiplying the percent change from 2019 to 2020 in traffic volume from the Virginia Department of Transportation with the business-as-usual 2020 U.S. Environmental Protection Agency estimate of CO2 emissions for Virginia’s transportation sector. We estimate Virginia’s 2020 COVID-19 transportation CO2 emissions reduction is around 15.0% (14.2 to 15.7%), with reduced passenger vehicle traffic making up the bulk of the inferred reduction. This study highlights the utility of reimagining our current transportation sector as a way to implement sustainable, state-level carbon reduction policies, such as the Clean Car Standards
Hippocampus and basal forebrain volumes modulate effects of anticholinergic treatment on delayed recall in healthy older adults
Introduction Volumes of hippocampus and cholinergic basal forebrain are associated with delayed recall performance and may modulate the effect of a muscarinic receptor antagonist on delayed recall in healthy volunteers Methods We studied 15 older adults before and after the oral administration of a single dose of 1 or 2 mg of the preferential M1 muscarinic receptor antagonist trihexyphenidyl (Artane™) or placebo in a double-blind randomized cross-over design. Hippocampus and basal forebrain volumes were measured using magnetic resonance imaging. Results We found a significant interaction between treatment and hippocampus volume and a trend level effect between treatment and anterior basal forebrain volume on task performance, with an attenuation of the association between volume size and performance with trihexyphenidyl. Discussion These findings suggest a reduction of delayed recall performance with increasing doses of the muscarinic antagonist that is related to an uncoupling of the association of task performance with cholinergic basal forebrain and hippocampus volume
Introduction to Forward Physics and Cosmic Rays at the Symposium on Multiparticle Dynamics ISMD 2010
We give a brief introduction to the topics discussed at the ISMD 2010 Symposium (Antwerp, 2010) on forward physics at the LHC and its interplay with cosmic rays physics
Integration of the CMS regional calorimeter Trigger hardware into the CMS level-1 Trigger
The electronics for the Regional Calorimeter Trigger (RCT) of the Compact Muon Solenoid Experiment (CMS) have been produced and tested. The RCT hardware consists of 18 double-sided crates containing custom boards, ASICs, and backplanes. The RCT receives 8-bit energies and a data quality bit from the HCAL and ECAL Trigger Primitive Generators (TPGs) and sends it to the CMS Global Calorimeter Trigger (GCT) after processing. Before installation, integration tests were performed. Data was successfully received from the TPG electronics and read out with a RCT Jet Capture Card. These tests, other tests involving more trigger subsystems, their results, and the RCT installation will be described
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