1,234 research outputs found
Immigrant community integration in world cities
As a consequence of the accelerated globalization process, today major cities
all over the world are characterized by an increasing multiculturalism. The
integration of immigrant communities may be affected by social polarization and
spatial segregation. How are these dynamics evolving over time? To what extent
the different policies launched to tackle these problems are working? These are
critical questions traditionally addressed by studies based on surveys and
census data. Such sources are safe to avoid spurious biases, but the data
collection becomes an intensive and rather expensive work. Here, we conduct a
comprehensive study on immigrant integration in 53 world cities by introducing
an innovative approach: an analysis of the spatio-temporal communication
patterns of immigrant and local communities based on language detection in
Twitter and on novel metrics of spatial integration. We quantify the "Power of
Integration" of cities --their capacity to spatially integrate diverse
cultures-- and characterize the relations between different cultures when
acting as hosts or immigrants.Comment: 13 pages, 5 figures + Appendi
Study of the Decays B0 --> D(*)+D(*)-
The decays B0 --> D*+D*-, B0 --> D*+D- and B0 --> D+D- are studied in 9.7
million Y(4S) --> BBbar decays accumulated with the CLEO detector. We determine
Br(B0 --> D*+D*-) = (9.9+4.2-3.3+-1.2)e-4 and limit Br(B0 --> D*+D-) < 6.3e-4
and Br(B0 --> D+D-) < 9.4e-4 at 90% confidence level (CL). We also perform the
first angular analysis of the B0 --> D*+D*- decay and determine that the
CP-even fraction of the final state is greater than 0.11 at 90% CL. Future
measurements of the time dependence of these decays may be useful for the
investigation of CP violation in neutral B meson decays.Comment: 21 pages, 5 figures, submitted to Phys. Rev.
Improved Measurement of the Pseudoscalar Decay Constant
We present a new determination of the Ds decay constant, f_{Ds} using 5
million continuum charm events obtained with the CLEO II detector. Our value is
derived from our new measured ratio of widths for Ds -> mu nu/Ds -> phi pi of
0.173+/- 0.021 +/- 0.031. Taking the branching ratio for Ds -> phi pi as (3.6
+/- 0.9)% from the PDG, we extract f_{Ds} = (280 +/- 17 +/- 25 +/- 34){MeV}. We
compare this result with various model calculations.Comment: 23 page postscript file, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
Measurement of B(/\c->pKpi)
The /\c->pKpi yield has been measured in a sample of two-jet continuum events
containing a both an anticharm tag (Dbar) as well as an antiproton (e+e- ->
Dbar pbar X), with the antiproton in the hemisphere opposite the Dbar. Under
the hypothesis that such selection criteria tag e+e- -> Dbar pbar (/\c) X
events, the /\c->pkpi branching fraction can be determined by measuring the
pkpi yield in the same hemisphere as the antiprotons in our Dbar pbar X sample.
Combining our results from three independent types of anticharm tags, we obtain
B(/\c->pKpi)=(5.0+/-0.5+/-1.2)
Search for the Decays B^0 -> D^{(*)+} D^{(*)-}
Using the CLEO-II data set we have searched for the Cabibbo-suppressed decays
B^0 -> D^{(*)+} D^{(*)-}. For the decay B^0 -> D^{*+} D^{*-}, we observe one
candidate signal event, with an expected background of 0.022 +/- 0.011 events.
This yield corresponds to a branching fraction of Br(B^0 -> D^{*+} D^{*-}) =
(5.3^{+7.1}_{-3.7}(stat) +/- 1.0(syst)) x 10^{-4} and an upper limit of Br(B^0
-> D^{*+} D^{*-}) D^{*\pm} D^\mp and
B^0 -> D^+ D^-, no significant excess of signal above the expected background
level is seen, and we calculate the 90% CL upper limits on the branching
fractions to be Br(B^0 -> D^{*\pm} D^\mp) D^+
D^-) < 1.2 x 10^{-3}.Comment: 12 page postscript file also available through
http://w4.lns.cornell.edu/public/CLNS, submitted to Physical Review Letter
Exoplanet Atmosphere Measurements from Transmission Spectroscopy and other Planet-Star Combined Light Observations
It is possible to learn a great deal about exoplanet atmospheres even when we
cannot spatially resolve the planets from their host stars. In this chapter, we
overview the basic techniques used to characterize transiting exoplanets -
transmission spectroscopy, emission and reflection spectroscopy, and full-orbit
phase curve observations. We discuss practical considerations, including
current and future observing facilities and best practices for measuring
precise spectra. We also highlight major observational results on the
chemistry, climate, and cloud properties of exoplanets.Comment: Accepted review chapter; Handbook of Exoplanets, eds. Hans J. Deeg
and Juan Antonio Belmonte (Springer-Verlag). 22 pages, 6 figure
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
Observation of the Charmed Baryon at CLEO
The CLEO experiment at the CESR collider has used 13.7 fb of data to
search for the production of the (css-ground state) in
collisions at {\rm GeV}. The modes used to
study the are ,
, , , and
. We observe a signal of 40.49.0(stat) events
at a mass of 2694.62.6(stat)1.9(syst) {\rm MeV/}, for all modes
combined.Comment: 10 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
Measurement of the Relative Branching Fraction of to Charged and Neutral B-Meson Pairs
We analyze 9.7 x 10^6 B\bar{B}$ pairs recorded with the CLEO detector to
determine the production ratio of charged to neutral B-meson pairs produced at
the Y(4S) resonance. We measure the rates for B^0 -> J/psi K^{(*)0} and B^+ ->
J/psi K^{(*)+} decays and use the world-average B-meson lifetime ratio to
extract the relative widths f+-/f00 = Gamma(Y(4S) -> B+B-)/Gamma(Y(4S) ->
B0\bar{B0}) = = 1.04 +/- 0.07(stat) +/- 0.04(syst). With the assumption that
f+- + f00 = 1, we obtain f00 = 0.49 +/- 0.02(stat) +/- 0.01(syst) and f+- =
0.51 +/- 0.02(stat) +/- 0.01(syst). This production ratio and its uncertainty
apply to all exclusive B-meson branching fractions measured at the Y(4S)
resonance.Comment: 11 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
- …
