978 research outputs found
UNIVERSITI SAINS MALAYSIA First Semester Examination 2016/2017 Academic Session December 2016 / January 2017 EBB 42713 — Technology and Application of Engineering Polymer [Teknologi dan Penggunaan Polimer Kejuruteraanl Duration : 3 hours [Masa : 3 jam]
Figure 1: The UltraHaptics system. Left: the hardware. Centre: a simulation of two focal points, with colour representing phase and brightness representing amplitude. Right: receiving two independent points of feedback while performing a pinch gesture. We introduce UltraHaptics, a system designed to provide multi-point haptic feedback above an interactive surface. UltraHaptics employs focused ultrasound to project discrete points of haptic feedback through the display and directly on to users ’ unadorned hands. We investigate the desirable properties of an acoustically transparent display and demonstrate that the system is capable of creating multiple localised points of feedback in mid-air. Through psychophysical experiments we show that feedback points with different tactile properties can be identified at smaller separations. We also show that users are able to distinguish between different vibration frequencies of non-contact points with training. Finally, we explore a number of exciting new interaction possibilities that UltraHaptics provides. Author Keywords Haptic feedback; touch screens; interactive tabletops
Applicability of Perturbative QCD to Decays
We examine the applicability of perturbative QCD to meson decays into
mesons. We find that the perturbative QCD formalism, which includes Sudakov
effects at intermediate energy scales, is applicable to the semi-leptonic decay
, when the meson recoils fast. Following this conclusion, we
analyze the two-body non-leptonic decays and . By
comparing our predictions with experimental data, we extract the matrix element
.Comment: 18 pages in Latex, figures are available upon reques
Improving Influenza and Tdap Vaccination during Pregnancy: A Cluster-randomized Trial of a Multi-component Antenatal Vaccine Promotion Package in Late Influenza Season
Background Evidence-based interventions to improve influenza vaccine coverage among pregnant women are needed, particularly among those who remain unvaccinated late into the influenza season. Improving rates of antenatal tetanus, diphtheria and acellular pertussis (Tdap) vaccination is also needed
Measurement of \cal{B}(D^+ --> mu^+ nu) and the Pseudoscalar Decay Constant
In 60 pb-1 of data taken on the psi(3770) resonance with the CLEO-c detector,
we find 8 D+ to mu+ nu event candidates that are mostly signal, containing only
1 estimated background. Using this statistically compelling sample, we measure
preliminary values of B(D+ to mu+ nu) = (3.5 +- 1.4 +- 0.6)*10^{-4}, and
determine f_{D+} =(201+- 41+- 17) MeV.Comment: 17 pages postscript, also available through
http://www.lns.cornell.edu/public/CONF/2004/, Presented at ICHEP Aug
16-22,2004, Beijing, Chin
Di-electron Widths of the Upsilon(1S,2S,3S) Resonances
We determine the di-electron widths of the Upsilon(1S), Upsilon(2S), and
Upsilon(3S) resonances with better than 2% precision by integrating the
cross-section of e+e- -> Upsilon over the e+e- center-of-mass energy. Using
e+e- energy scans of the Upsilon resonances at the Cornell Electron Storage
Ring and measuring Upsilon production with the CLEO detector, we find
di-electron widths of 1.354 +- 0.004 (stat) +- 0.020 (syst) keV, 0.619 +- 0.004
+- 0.010 keV, and 0.446 +- 0.004 +- 0.007 keV for the Upsilon(1S), Upsilon(2S),
and Upsilon(3S), respectively.Comment: 9 pages, 4 figures, also available through
http://www.lns.cornell.edu/public/CLNS/2005/, published in PRL; corrected
numerical values in abstrac
Search for Lepton Flavor Violation in Upsilon Decays
In this Letter we describe a search for lepton flavor violation (LFV) in the
bottomonium system. We search for leptonic decays of Upsilon(nS)(n=1,2, and 3)
into muon and tau using the data collected with the CLEO III detector. We
identify the tau lepton using its leptonic decay into electron and utilize
multidimensional likelihood fitting with PDF shapes measured from independent
data samples. We report our estimates of 95% CL upper limits on LFV branching
fractions of Upsilon mesons. We interpret our results in terms of the exclusion
plot for the energy scale of a hypothetical new interaction versus its
effective LFV coupling in the framework of effective field theory.Comment: 10 pages, 3 figures, available through
http://www.lns.cornell.edu/public/CLNS/, submitted to PR
New Measurements of Upsilon(1S) Decays to Charmonium Final States
Using substantially larger data samples collected by the CLEO III detector,
we report on new measurements of the decays of Upsilon(1S) to charmonium final
states, including J/Psi, psi(2S), and chi_cJ. The latter two are first
observations of these decays. We measure the branching fractions as follows:
B(Y(1S)--> J/Psi+X)=(6.4+-0.4+-0.6)x10^-4, B(Y(1S)--> psi(2S)+X)/B(Y(1S)-->
J/Psi+X)=0.41+-0.11+-0.08, B(Y(1S)--> chi_c1+X)/B(Y(1S)-->
J/Psi+X)=0.35+-0.08+-0.06, B(Y(1S)--> chi_c2+X)/B(Y(1S)-->
J/Psi+X)=0.52+-0.12+-0.09, and B(Y(1S)--> chi_c0+X)/B(Y(1S)--> J/Psi+X)<7.4% at
90% confidence level. We also report on the momentum and angular spectra of
J/Psi's in Upsilon(1S) decay. The results are compared to predictions of the
color octet and color singlet models.Comment: 27 pages postscript,also available through
http://w4.lns.cornell.edu/public/CLNS/, submitted to PR
The Search for eta(1440) --> K^0_S K^pm \pi^mp in Two-Photon Fusion at CLEO
We analyze 13.8 \rm fb^{-1} of the integrated e^+e^- luminosity collected at
10.6 GeV center-of-mass energy with the CLEO II and CLEO II.V detectors to
study exclusive two-photon production of hadrons with masses below 1.7{\rm \
GeV/c^2} decaying into the K^0_S K^\pm \pi^\mp final state. We observe two
statistically significant enhancements in the \eta(1440) mass region. These
enhancements have large transverse momentum which rules them out as being due
to pseudoscalar resonances but is consistent with the production of
axial-vector mesons. We use tagged two-photon events to study the properties of
the observed enhancements and associate them with the production of f_1(1285)
and f_1(1420). Our non-observation of \eta(1440) is inconsistent by more than
two standard deviations with the first observation of this resonance in
two-photon collisions by the L3 experiment. We present our estimates for 90%
confidence level upper limits on the products of two-photon partial widths of
pseudoscalar hadrons and their branching fractions into
K^0_S(\pi^+\pi^-)K^\pm\pi^\mp.Comment: 24 pages postscript,also available through
http://www.lns.cornell.edu/public/CLNS/2004/, submitted to PR
Update of the measurement of the cross section for e^+e^- -> psi(3770) -> hadrons
We have updated our measurement of the cross section for e^+e^- -> psi(3770)
-> hadrons, our publication "Measurement of sigma(e^+e^- -> psi(3770) ->
hadrons) at E_{c.m.} = 3773 MeV", arXiv:hep-ex/0512038, Phys.Rev.Lett.96,
092002 (2006). Simultaneous with this arXiv update, we have published an
erratum in Phys.Rev.Lett.104, 159901 (2010). There, and in this update, we have
corrected a mistake in the computation of the error on the difference of the
cross sections for e^+e^- -> psi(3770) -> hadrons and e^+e^- -> psi(3770) ->
DDbar. We have also used a more recent CLEO measurement of cross section for
e^+e^- -> psi(3770) -> DDbar. From this, we obtain an upper limit on the
branching fraction for psi(3770) -> non-DDbar of 9% at 90% confidence level.Comment: 3 pages, 0 figures. This is an erratum to
Phys.Rev.Lett.96:092002,2006. Added a reference
Measurement of Absolute Hadronic Branching Fractions of D Mesons and e^+ e^- --> D D-bar Cross Sections at the psi(3770)
Using 281 /pb of e^+ e^- collisions recorded at the psi(3770) resonance with
the CLEO-c detector at CESR, we determine absolute hadronic branching fractions
of charged and neutral D mesons using a double tag technique. Among
measurements for three D^0 and six D^+ modes, we obtain reference branching
fractions B(D^0 --> K^-pi^+) = (3.891 +- 0.035 +- 0.059 +- 0.035)% and B(D^+
--> K^-pi^+pi^+) = (9.14 +- 0.10 +- 0.16 +- 0.07)%, where the first uncertainty
is statistical, the second is all systematic errors other than final state
radiation (FSR), and the third is the systematic uncertainty due to FSR. We
include FSR in these branching fractions by allowing for additional unobserved
photons in the final state. Using an independent determination of the
integrated luminosity, we also extract the cross sections sigma(e+e- --> D^0
D^0-bar) = (3.66+- 0.03 +- 0.06) nb and sigma(e+e- --> D^+ D^-) = (2.91+- 0.03
+- 0.05) nb at a center of mass energy, E_cm = 3774 +- 1 MeV.Comment: 47 pages, postscript also available through this
http://www.lns.cornell.edu/public/CLNS/2007/, to be published in PRD, updated
branching fractions using B(KS0 --> pi+ pi-) from PDG 2007, and updated text
in response to the PRD reviewe
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