24,002 research outputs found
The Top Priority: Precision Electroweak Physics from Low to High Energy
Overall, the Standard Model describes electroweak precision data rather well.
There are however a few areas of tension (charged current universality, NuTeV,
(g-2)_\mu, b quark asymmetries), which I review emphasizing recent theoretical
and experimental progress. I also discuss what precision data tell us about the
Higgs boson and new physics scenarios. In this context, the role of a precise
measurement of the top mass is crucial.Comment: 12 pages; invited talk at 21st International Symposium on Lepton and
Photon Interactions at High Energies (LP 03), Batavia, Illinois, 11-16 Aug
200
EXAMINING QUALITY INDICATOR RATES FOR OLDER HOME CARE CLIENTS WITH DUAL SENSORY IMPAIRMENT (DSI) AND EXPLORING THE HETEROGENEITY WITHIN DSI.
Older adults with impairments in both hearing and vision, called dual sensory impairment (DSI), are at an increased risk of negative health outcomes such as impaired communication and difficulties with mobility. It is unknown whether DSI is associated with potential quality of care issues. This study used a set of home care quality indicators (HCQIs) to examine potential quality issues in older clients (65+) with DSI. Further, it looked to explore how HCQI rates differed based on the geographic region of care and whether the client’s level of hearing and vision impairment was related to certain HCQIs. The HCQIs were generated from data collected using the Resident Assessment Instrument for Home Care and capture undesirable outcomes (e.g., falls, cognitive decline). Higher rates indicate a greater frequency of experiencing the issue. In this sample (n=352,656), the average age was 82.8 years (sd=7.9), the majority were female (63.2%), and 20.5% experienced DSI. Compared to those without DSI, clients with DSI had higher rates across 20 of the 22 HCQIs. The HCQI rates differed by geographic region, with specific regions consistently performing worse than others. Finally, the level of hearing and vision impairment was related to certain HCQIs more than others, for example hearing impairment appeared to be more related to the quality indicator measuring communication difficulty. Overall, the hope is that this information can help to identify some of the potential issues around quality and in turn, assist in continually improving the services being provided to these clients
Education alignment
This essay reviews recent developments in embedding data
management and curation skills into information technology,
library and information science, and research-based
postgraduate courses in various national contexts. The essay
also investigates means of joining up formal education with
professional development training opportunities more
coherently. The potential for using professional internships as a
means of improving communication and understanding between
disciplines is also explored. A key aim of this essay is to identify
what level of complementarity is needed across various
disciplines to most effectively and efficiently support the entire
data curation lifecycle
Strange quark asymmetry in the nucleon and the NuTeV anomaly
The NuTeV anomaly of a non-universal value of the fundamental parameter
sin^2\theta_W in the electroweak theory has been interpreted as an indication
for new physics beyond the Standard Model. However, the observed quantity
depends on a possible asymmetry in the momentum distributions of strange quarks
and antiquarks in the nucleon. This asymmetry occurs naturally in a
phenomenologically successful physical model for such parton distributions,
which reduces the NuTeV result to only about two standard deviations from the
Standard Model.Comment: 4 pages, 5 figures, RevTex4. Updated with new references and extended
discussion. v.3: Minor corrections mad
Interpretations of the NuTeV
We summarize theoretical explanations of the three discrepancy
between measured by NuTeV and predicted by the Standard Model
global fit. Possible new physics explanations ({\it e.g.} an unmized ) are
not compelling. The discrepancy would be reduced by a positive momentum
asymmetry in the strange sea; present experimental estimates of are
unreliable or incomplete. Upgrading the NuTeV analysis to NLO would alleviate
concerns that the discrepancy is a QCD effect.Comment: (proceedings for the NuFact'02 Workshop); reference and footnote
added, following the NuTeV proceeding
Modified Paschos-Wolfenstein relation and extraction of weak mixing angle sin^2 theta_W
The NuTeV collaboration reported anomalously large weak mixing angle sin^2
theta_W in comparison with the standard model prediction. Neutrino and
antineutrino charged- and neutral-current events are analyzed for extracting
sin^2 theta_W. Although the Paschos-Wolfenstein relation is not directly used
in the analysis, it plays an important role in the determination. Noting that
the target nucleus, iron, is not an isoscalar nucleus, we derive a
leading-order expression for a modified Paschos-Wolfenstein relation for
nuclei, which may have neutron excess. Then, using charge and baryon-number
conservations for nuclei, we discuss a nuclear correction in the sin^2 theta_W
determination. It is noteworthy that nuclear modifications are different
between valence up- and down-quark distributions. We show this difference
effect on the NuTeV sin^2 theta_W deviation.Comment: 5 pages, REVTeX4.0, revtex4.cls, url.sty, natbib.sty, revsymb.sty,
10pt.rtx, aps.rtx, amssymb.sty, amsfonts.sty, 3 eps figures. Phys. Rev. D in
press. Email: [email protected] See also http://hs.phys.saga-u.ac.j
Unitary ambiguity in the extraction of the E2/M1 ratio for the transition
The resonant electric quadrupole amplitude in the transition is of great interest for the understanding of
baryon structure. Various dynamical models have been developed to extract it
from the corresponding photoproduction multipole of pions on nucleons. It is
shown that once such a model is specified, a whole class of unitarily
equivalent models can be constructed, all of them providing exactly the same
fit to the experimental data. However, they may predict quite different
resonant amplitudes. Therefore, the extraction of the E2/M1() ratio (bare or dressed) which is based on a dynamical
model using a largely phenomenological interaction is not unique.Comment: 10 pages revtex including 4 postscript figure
Unified Universal Seesaw Models
A set of Grand Unified Theories based upon the gauge groups SU(5)_\L \times
SU(5)_\R, SO(10)_\L \times SO(10)_\R and SU(4)_\C \times SU(4)_\L \times
SU(4)_\R is explored. Several novel features distinguish these theories from
the well-known , and SU(4)_\C \times SU(2)_\L \times SU(2)_\R
models which they generalize. Firstly, Standard Model quarks and leptons are
accompanied by and mix with heavy SU(2)_\L \times SU(2)_\R singlet partners.
The resulting fermion mass matrices are seesaw in form. Discrete parity
symmetries render the determinants of these mass matrices real and eliminate CP
violating gauge terms. The unified seesaw models consequently provide a
possible resolution to the strong CP problem. Secondly, \sinsq at the
unification scale is numerically smaller than the experimentally measured
scale value. The weak angle must therefore increase as it evolves down in
energy. Finally, proton decay is suppressed by small seesaw mixing factors in
all these theories.Comment: 22 pages with 2 figures not included but available upon request,
CALT-68-185
QCD Corrections in two-Higgs-doublet extensions of the Standard Model with Minimal Flavor Violation
We present the QCD corrections to R_b and to the Delta B=1 effective
Hamiltonian in models with a second Higgs field that couples to the quarks
respecting the criterion of Minimal Flavor Violation, thus belonging either to
the (1,2)_1/2 or to the (8,2)_1/2 representation of SU(3)xSU(2)xU(1). After the
inclusion of the QCD corrections, the prediction for R_b becomes practically
insensitive to the choice of renormalization scheme for the top mass, which for
the type-I and type-II models translates in a more robust lower bound on
tan(beta). The QCD-corrected determinations of Rb and BR(B->Xs gamma) are used
to discuss the constraints on the couplings of a (colored) charged Higgs boson
to top and bottom quarks.Comment: 19 pages, 7 figures. v2: version published in Phys. Rev. D, with
additional reference and not
Updated Bounds on Milli-Charged Particles
We update the bounds on fermions with electric charge and mass . For m_\epsilon\lsim m_e we find 10^{-15}\lsim\epsilon<1 is excluded by laboratory experiments, astrophysics and cosmology. For larger masses, the limits are less restrictive and depend on . For milli-charged neutrinos, the limits are stronger, especially if the different flavors mix as suggested by current experimental evidence
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