2,532 research outputs found
Alien Registration- Mcleod, Annie H. (Brownville, Piscataquis County)
https://digitalmaine.com/alien_docs/11252/thumbnail.jp
Charmonium properties from lattice QCD + QED: hyperfine splitting, leptonic width, charm quark mass and
We have performed the first lattice QCD computations of the
properties (masses and decay constants) of ground-state charmonium mesons. Our
calculation uses the HISQ action to generate quark-line connected two-point
correlation functions on MILC gluon field configurations that include
quark masses going down to the physical point, tuning the quark mass from
and including the effect of the quark's electric charge
through quenched QED. We obtain (connected) =
120.3(1.1) MeV and interpret the difference with experiment as the impact on
of its decay to gluons, missing from the lattice calculation. This
allows us to determine =+7.3(1.2) MeV,
giving its value for the first time. Our result of 0.4104(17)
GeV, gives =5.637(49) keV, in agreement
with, but now more accurate than experiment. At the same time we have improved
the determination of the quark mass, including the impact of quenched QED
to give = 0.9841(51) GeV. We have also used
the time-moments of the vector charmonium current-current correlators to
improve the lattice QCD result for the quark HVP contribution to the
anomalous magnetic moment of the muon. We obtain , which is 2.5 higher than the value derived using moments
extracted from some sets of experimental data on . This value for includes our determination of
the effect of QED on this quantity, .Comment: Added extra discussion on QED setup, some new results to study the
effects of strong isospin breaking in the sea (including new Fig. 1) and a
fit stability plot for the hyperfine splitting (new Fig. 7). Version accepted
for publication in PR
QED interaction effects on heavy meson masses from lattice QCD+QED
Hadron masses are subject to few MeV corrections arising from QED
interactions, almost entirely arising from the electric charge of the valence
quarks. The QED effects include both self-energy contributions and interactions
between the valence quarks/anti-quarks. By combining results from different
signs of the valence quark electric charge we are able to isolate the
interaction term which is dominated by the Coulomb piece, , in the
nonrelativistic limit. We study this for , and mesons,
working in lattice QCD plus quenched QED. We use gluon field configurations
that include up, down, strange and charm quarks in the sea at multiple values
of the lattice spacing. Our results, including also values for mesons with
quarks heavier than charm, can be used to improve phenomenological models for
the QED contributions. The QED interaction term carries information about meson
structure; we derive effective sizes
for , and of 0.206(8) fm, 0.321(14) fm and 0.307(31) fm
respectively.Comment: 8 pages, 3 figure
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Selective deposition of silver and copper films by condensation coefficient modulation
Whilst copper and silver are the conductors of choice for myriad current and emerging applications, patterning these metals is a slow and costly process. We report the remarkable finding that an extremely thin (∼10 nm) printed layer of specific organofluorine compounds enables selective deposition of copper and silver vapour, with metal condensing only where the organofluorine layer is not. This unconventional approach is fast, inexpensive, avoids metal waste and the use of harmful chemical etchants, and leaves the metal surface uncontaminated. We have used this approach to fabricate thin films of these metals with 6 million apertures cm−2 and grids of ∼1 μm lines, through to 10 cm diameter apertures. We have also fabricated semi-transparent organic solar cells in which the top silver electrode is patterned with a dense array of 2 μm diameter apertures, which cannot be achieved by any other scalable means directly on an organic electronic device
Renormalisation of the tensor current in lattice QCD and the tensor decay constant
Lattice QCD calculations of form factors for rare Standard Model processes
such as use tensor currents that require
renormalisation. These renormalisation factors, , have typically been
calculated within perturbation theory and the estimated uncertainties from
missing higher order terms are significant. Here we study tensor current
renormalisation using lattice implementations of momentum-subtraction schemes.
Such schemes are potentially more accurate but have systematic errors from
nonperturbative artefacts. To determine and remove these condensate
contributions we calculate the ground-state charmonium tensor decay constant,
, which is also of interest in beyond the Standard Model studies.
We obtain GeV, with
ratio to the vector decay constant of 0.9569(52), significantly below 1. We
also give factors, converted to the scheme, corrected
for condensate contamination. This contamination reaches 1.5\% at a
renormalisation scale of 2 GeV (in the preferred RI-SMOM scheme) and so must be
removed for accurate results.Comment: 12 pages, version accepted for publication in PR
The effect of the inclusion of trunk-strengthening exercises to a multimodal exercise program on physical activity levels and psychological functioning in older adults: Secondary data analysis of a randomized controlled trial
Background
Engaging in multimodal exercise program helps mitigate age-related decrements by improving muscle size, muscle strength, balance, and physical function. The addition of trunk-strengthening within the exercise program has been shown to significantly improve physical functioning outcomes. Whether these improvements result in improved psychological outcomes associated with increased physical activity levels requires further investigation. We sought to explore whether the inclusion of trunk-strengthening exercises to a multimodal exercise program improves objectively measured physical activity levels and self-reported psychological functioning in older adults.
Method
We conducted a secondary analysis within a single-blinded parallel-group randomized controlled trial. Sixty-four healthy older (≥ 60 years) adults were randomly allocated to a 12-week walking and balance exercise program with (n = 32) or without (n = 32) inclusion of trunk strengthening exercises. Each program involved 12 weeks of exercise training, followed by a 6-week walking-only program (identified as detraining). Primary outcome measures for this secondary analysis were physical activity (accelerometry), perceived fear-of-falling, and symptoms of anxiety and depression.
Results
Following the 12-week exercise program, no significant between-group differences were observed for physical activity, sedentary behaviour, fear-of-falling, or symptoms of anxiety or depression. Significant within-group improvements (adjusted mean difference [95%CI]; percentage) were observed in moderate-intensity physical activity (6.29 [1.58, 11.00] min/day; + 26.3%) and total number of steps per min/day (0.81 [0.29 to 1.33] numbers or + 16.3%) in trunk-strengthening exercise group by week 12. With respect to within-group changes, participants in the walking-balance exercise group increased their moderate-to-vigorous physical activity (MVPA) (4.81 [0.06 to 9.56] min/day; + 23.5%) and reported reduction in symptoms of depression (-0.26 [-0.49 to -0.04] points or -49%) after 12 weeks of the exercise program. The exercise-induced increases in physical activity levels in the trunk-strengthening exercise group were abolished 6-weeks post-program completion. While improvements in physical activity levels were sustained in the walking-balance exercise group after detraining phase (walking only).
Conclusions
The inclusion of trunk strengthening to a walking-balance exercise program did not lead to statistically significant between-group improvements in physical activity levels or psychological outcomes in this cohort following completion of the 12-week exercise program
MicroRNA expression in lymphocyte development and malignancy
This article is available open access through the publisher’s website. Copyright @ 2008 Macmillan Publishers Limited.No abstract available.The Leukemia Research Fund, the Julian Starmer-Smith Memorial Fund, and the Medical Research Council
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