Faculty
Publications: August, 2008
Query
Results from the Smithsonian/NASA
Astrophysics Data System (ADS)
| Title: |
Observation of the
Bottomonium Ground State in the Decay Υ(3S)→γηb |
| Authors: |
Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Tico,;... Morii, M.;...;
and 530 coauthors. |
| Publication: |
Physical Review Letters,
vol. 101, Issue 7, id. 071801 (PhRvL
Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
APS |
| Abstract Copyright: |
(c) 2008: The American
Physical Society |
| DOI: |
10.1103/PhysRevLett.101.071801 |
| Bibliographic
Code: |
2008PhRvL.101g1801A |
Abstract: We report the results of a search for the bottomonium
ground state η
b(1S) in the photon energy spectrum
with a sample of (109±1) million of Υ(3S) recorded at
the Υ(3S) energy with the BABAR detector at the PEP-II
B factory at SLAC. We observe a peak in the photon energy
spectrum at E
γ=921.2
-2.8+2.1(stat)±2.4(syst)MeV
with a significance of 10 standard deviations. We interpret
the observed peak as being due to monochromatic photons
from the radiative transition Υ(3S)→γη
b(1S).
This photon energy corresponds to an η
b(1S)
mass of 9388.9
-2.3+3.1(stat)±2.7(syst)MeV/c
2.
The hyperfine Υ(1S)-η
b(1S) mass splitting
is 71.4
-3.1+2.3(stat)±2.7(syst)MeV/c
2.
The branching fraction for this radiative Υ(3S) decay
is estimated to be [4.8±0.5(stat)±1.2(syst)]×10
-4.
Abstract: We demonstrate
optical nonlinearities due to the interaction of weak
optical fields with the collective motion of a strongly
dispersive ultracold gas. The combination of a recoil-induced
resonance in the high gain regime and optical waveguiding
within the dispersive medium enables us to achieve a
collective atomic cooperativity of 275±50 even in the
absence of a cavity. As a result, we observe optical
bistability at input powers as low as 20 pW. The present
scheme allows for dynamic optical control of the dispersive
properties of the ultracold gas using very weak pulses
of light. The experimental observations are in good agreement
with a theoretical model.
| Title: |
Measurement of the
spin of the Ξ(1530) resonance |
| Authors: |
Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prudent, X.; Tisserand, V.; Zghiche, A.; Tico, J. Garra;... Morii, M.;...;
and 539 coauthors. |
| Publication: |
Physical Review D,
vol. 78, Issue 3, id. 034008 (PhRvD
Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
APS |
| Abstract Copyright: |
(c) 2008: The American
Physical Society |
| DOI: |
10.1103/PhysRevD.78.034008 |
| Bibliographic
Code: |
2008PhRvD..78c4008A |
Abstract: The properties of the Ξ(1530) resonance are investigated
in the Λ
c+→Ξ
-π
+K
+ decay
process. The data sample was collected with the BABAR
detector at the SLAC PEP-II asymmetric-energy e
+e
- collider
operating at center-of-mass energies 10.58 and 10.54
GeV. The corresponding integrated luminosity is approximately
230fb
-1. The spin of the Ξ(1530) is established
to be 3/2. The existence of an S-wave amplitude in the
Ξ
-π
+ system is inferred, and its
interference with the Ξ(1530)
0 amplitude provides
the first clear demonstration of the Breit-Wigner phase
motion expected for the Ξ(1530). The P
1(cosθ
Ξ-)
Legendre polynomial moment indicates the presence of
a significant S-wave amplitude for Ξ
-π
+ mass
values above 1.6GeV/c
2, and a dip in the mass
distribution at approximately 1.7GeV/c
2 is
interpreted as due to the coherent addition of a Ξ(1690)
0 contribution
to this amplitude. This would imply J
P=1/2
- for
the Ξ(1690). Attempts at fitting the Ξ(1530)
0 line
shape yield unsatisfactory results, and this failure
is attributed to interference effects associated with
the amplitudes describing the K
+π
+ and/or
Ξ
-K
+ systems.
| Title: |
Measurement of the
branching fractions of the rare decays B0→Ds(*)+π-,
B0→Ds(*)+ρ-,
and B0→Ds(*)-K(*)+ |
| Authors: |
Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Tico,;... Morii, M.;...;
and 535 coauthors. |
| Publication: |
Physical Review D,
vol. 78, Issue 3, id. 032005 (PhRvD
Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
APS |
| Abstract Copyright: |
(c) 2008: The American
Physical Society |
| DOI: |
10.1103/PhysRevD.78.032005 |
| Bibliographic
Code: |
2008PhRvD..78c2005A |
Abstract: We report the measurement of the branching fractions
of the rare decays B
0→D
s(*)+π
-,
B
0→D
s(*)+ρ
-,
and B
0→D
s(*)-K
(*)+ in
a sample of 381×10
6Υ(4S) decays into B&Bmacr;
pairs collected with the BABAR detector at the PEP-II
asymmetric-energy e
+e
- storage
ring. We present evidence for the decay B
0→D
s-K
*+ and
the vector-vector decays B
0→D
s*+ρ
- and
B
0→D
s*-K
*+,
as well as the first measurement of the vector meson
polarization in these decays. We also determine the ratios
of the CKM-suppressed to CKM-favored amplitudes r(D
(*)π)
and r(D
(*)ρ) in decays B
0→D
(*)±π
∓ and
B
0→D
(*)±ρ
∓, and comment
on the prospects for measuring the CP observable sin(2β+γ).
Abstract: We suggest and analyze a technique for efficient and
robust creation of dense ultracold molecular ensembles
in their ground rovibrational state. In our approach
a molecule is brought to the ground state through a series
of intermediate vibrational states via a multistate chainwise
stimulated Raman adiabatic passage technique. We study
the influence of the intermediate states decay on the
transfer process and suggest an approach that minimizes
the population of these states, resulting in a maximal
transfer efficiency. As an example, we analyze the formation
of Rb287 starting from an initial Feshbach molecular
state and taking into account major decay mechanisms
due to inelastic atom-molecule and molecule-molecule
collisions. Numerical analysis suggests a transfer efficiency >90%
, even in the presence of strong collisional relaxation
as are present in a high density atomic gas.
| Title: |
The ATLAS Experiment
at the CERN Large Hadron Collider |
| Authors: |
The ATLAS Collaboration; Aad, G.; Abat, E.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B. A.; Abolins, M.; Abramowicz, H.;...; Brandenburg, G. W.;... Feldman, G.;... Guimaraes da Costa, J.;... Huth, J.;... Morii, M.;...;
and 2912 coauthors. |
| Publication: |
Journal of Instrumentation,
Volume 08, Issue 08, pp. S08003 (2008). |
| Publication
Date: |
08/2008 |
| Origin: |
IOP |
| Abstract Copyright: |
(c) 2008: The American
Physical Society |
| DOI: |
10.1088/1748-0221/3/08/S08003 |
| Bibliographic
Code: |
2008JInst..08S8003T |
Abstract: The ATLAS detector
as installed in its experimental cavern at point 1 at
CERN is described in this paper. A brief overview of
the expected performance of the detector when the Large
Hadron Collider begins operation is also presented.
Abstract: We consider the
one-loop partition function of free quantum field theory
in locally Anti-de Sitter space-times. In three dimensions,
the one loop determinants for scalar, gauge and graviton
excitations are computed explicitly using heat kernel
techniques. We obtain precisely the result anticipated
by Brown and Henneaux: the partition function includes
a sum over "boundary excitations" of AdS3, which are
the Virasoro descendants of empty Anti-de Sitter space.
This result also allows us to compute the one-loop corrections
to the Euclidean action of the BTZ black hole as well
its higher genus generalizations.
| Title: |
Real-time, local
basis-set implementation of time-dependent density
functional theory for excited state dynamics
simulations |
| Authors: |
Meng, Sheng; Kaxiras, Efthimios |
| Publication: |
Journal of Chemical
Physics, Volume 129, Issue 5, pp. 054110-054110-12
(2008). (JChPh
Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
AIP |
| Keywords: |
carbon compounds,
density functional theory, excited states, ground
states, hydrogen neutral molecules, organic compounds,
ozone, polarisability, wave functions |
| Abstract
Copyright: |
(c) 2008: American
Institute of Physics |
| DOI: |
10.1063/1.2960628 |
| Bibliographic
Code: |
2008JChPh.129e4110M |
Abstract: We present a method suitable for large-scale accurate
simulations of excited state dynamics within the framework
of time-dependent density functional theory (DFT). This
is achieved by employing a local atomic basis-set representation
and real-time propagation of excited state wave functions.
We implement the method within SIESTA, a standard ground-state
DFT package with local atomic basis, and demonstrate
its potential for realistic and accurate excited state
dynamics simulations using small and medium-sized molecules
as examples (H2, CO, O3, and indolequinone). The method
can be readily applied to problems involving nanostructures
and large biomolecules.
Abstract: We study the localization of vibrational modes of frictionless
granular media. We introduce a new method, motivated
by earlier work on non-Hermitian quantum problems, which
works well both in the localized regime where the localization
length ξ is much less than the linear size L and in the
regime ξgsimL when modes are extended throughout our
finite system. Our very lowest frequency modes show "quasi-localized" resonances
away from the jamming point; the spatial extent of these
regions increases as the jamming point is approached,
as expected theoretically. Throughout the remaining frequency
range, our data show no signature of the nearness of
the jamming point and collapse well when properly rescaled
with the system size. Using Random Matrix Theory, we
derive the scaling relation ξ~Ld/2 for the regime ξGtL
in d dimensions.
Abstract: We study instanton contributions to the superpotential
of local F-theory compactifications which could potentially
be used to engineer models of dynamical supersymmetry
breaking. These instantons correspond to Euclidean 3-branes
which form a threshold bound state with spacetime filling
7-branes. In certain cases, their contributions to the
effective 4-dimensional superpotential can be determined
in both perturbative string theory as well as directly
via the topologically twisted theory on the 3-brane worldvolume
and in all cases we observe an exact match between these
results. We further present an instanton generated Polonyi-like
model, and characterize subleading corrections to the
superpotential which arise from multi-instantons. We
also study instanton contributions to 4d pure N=1 SU(N)
gauge theory realized by a stack of 7-branes wrapping
a rigid 4-cycle and find that there is a non-trivial
contribution to the glueball superpotential from the
single instanton sector. This correction is absent in
the purely 4d theory and could conceivably be used either
to stabilize moduli or to break supersymmetry.
| Title: |
ZZ boundary states
and fragmented AdS2 spaces |
| Authors: |
Giombi, Simone; Yin, Xi |
| Publication: |
eprint arXiv:0808.0923 |
| Publication
Date: |
08/2008 |
| Origin: |
ARXIV |
| Keywords: |
High Energy Physics
- Theory |
| Comment: |
27 pages, 14 figures |
| Bibliographic
Code: |
2008arXiv0808.0923G |
Abstract: In this paper we show that Liouville gravity on the strip
with Zamolodchikov-Zamolodchikov (ZZ) boundary conditions
has a semi-classical interpretation in terms of fragmented
AdS2 spacetime geometries. Further, we study the three-point
functions of the ZZ boundary states, and show that they
are dominated by multi-AdS2 instantons in the classical
limit.
| Title: |
A Simple Proof of
the Chiral Gravity Conjecture |
| Authors: |
Strominger, Andrew |
| Publication: |
eprint arXiv:0808.0506 |
| Publication
Date: |
08/2008 |
| Origin: |
ARXIV |
| Keywords: |
High Energy Physics
- Theory |
| Comment: |
7 pages |
| Bibliographic
Code: |
2008arXiv0808.0506S |
Abstract: Chiral gravity is three-dimensional asymptotically AdS3
gravity with an Einstein, cosmological, and Chern-Simons
term at a critical value of the coupling denoted \mu\ell=1.
Ordinarily, excitations of AdS3 gravity are known to
transform non-trivially under an asymptotic symmetry
group consisting of both a left-moving and a right-moving
conformal group. However it was recently conjectured
in arXiv:0801.4566 that at the chiral point \mu\ell=1
all excitations are chiral in that they transform only
under the right-moving conformal group. We show herein
that at the chiral point, the group of trivial diffeomorphisms
is enhanced to include the left-moving conformal transformations,
and the asymptotic symmetry group contains only one (right-moving)
copy of the conformal group. Diffeomorphism invariance
then requires that all physical excitations are annihilated
by left-moving conformal transformations, establishing
nonperturbatively the chiral nature of chiral gravity.
| Title: |
Interferometric probe
of paired states |
| Authors: |
Gritsev, V.; Demler, E.; Polkovnikov, A. |
| Publication: |
eprint arXiv:0808.0499 |
| Publication
Date: |
08/2008 |
| Origin: |
ARXIV |
| Keywords: |
Condensed Matter
- Other, Condensed Matter - Superconductivity |
| Comment: |
17 pages, 5 figures |
| Bibliographic
Code: |
2008arXiv0808.0499G |
Abstract: We propose a new method for detecting paired states in
either bosonic or fermionic systems using interference
experiments with independent or weakly coupled low dimensional
systems. We demonstrate that our method can be used to
detect both the FFLO and the d-wave paired states of
fermions, as well as quasicondensates of singlet pairs
for polar F=1 atoms in two dimensional systems. We discuss
how this method can be used to perform phase-sensitive
determination of the symmetry of the pairing amplitude.
| Title: |
Deconfined criticality
and supersymmetry |
| Authors: |
Sachdev, Subir; Yin, Xi |
| Publication: |
eprint arXiv:0808.0191 |
| Publication
Date: |
08/2008 |
| Origin: |
ARXIV |
| Keywords: |
Condensed Matter
- Strongly Correlated Electrons, High Energy
Physics - Theory |
| Comment: |
19 pages |
| Bibliographic
Code: |
2008arXiv0808.0191S |
Abstract: We make connections between studies in the condensed
matter literature on quantum phase transitions in square
lattice antiferromagnets, and results in the particle
theory literature on abelian supersymmetric gauge theories
in 2+1 dimensions. In particular, we point out that supersymmetric
U(1) gauge theories (with particle content similar, but
not identical, to those of theories of doped antiferromagnets)
provide rigorous examples of deconfined critical points
and quantum phase transitions which do not obey the Landau-Ginzburg-Wilson
paradigm. We also make connections between supersymmetric
mirror symmetries and condensed matter particle-vortex
dualities.
| Title: |
Cryogenic Particle
Accumulation In ATRAP And The First Antihydrogen
Production Within A Magnetic Gradient Trap For
Neutral Antimatter |
| Authors: |
Storry, C. H.; Carew, A.; Comeau, D.; Hessels, E. A.; Weel, M.; George, M. C.; Grzonka, D.; Oelert, W.; Sefzick, T.; Zhang, Z.; Gabrielse, G.; Larochelle, P.; Lesage, D.; Levitt, B.; Kolthammer, W. S.; McConnell, R.; Richerme, P.; Wrubel, J.; Speck, A.; Markert, F.; Nillius, F.; Scheid, M.; Walz, J. |
| Publication: |
PROCEEDINGS OF THE
WORKSHOP ON COLD ANTIMATTER PLASMAS AND APPLICATION
TO FUNDAMENTAL PHYSICS. AIP Conference Proceedings,
Volume 1037, pp. 254-265 (2008). (AIPC
Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
AIP |
| Keywords: |
cryogenic electronics,
protons, antimatter, moderators |
| Abstract
Copyright: |
(c) 2008: American
Institute of Physics |
| DOI: |
10.1063/1.2977845 |
| Bibliographic
Code: |
2008AIPC.1037..254S |
Abstract: ATRAP has made many important improvements since CERN's
Antiproton Decelerator (AD) was restarted in 2006. These
include substantial increases in the number of positrons
(e+) and antiprotons (Pbars) used to make antihydrogen
(Hbar) atoms, a new technique for loading electrons (e-)
that are used to cool Pbars and e+, implementation of
a completely new, larger and more robust apparatus in
our second experimental zone and the inclusion of a quadrupole
Ioffe trap intended to trap the coldest Hbar atoms produced.
Using this new apparatus we have produced large numbers
of Hbar atoms within a Penning trap that is located within
this quadrupole Ioffe trap using a new technique which
shows promise for producing even colder atoms. These
observed Hbar atoms resolve a debate about whether positrons
and antiprotons can be brought together to form atoms
within the divergent magnetic fields of a quadrupole
Ioffe trap.
| Title: |
Near-infrared enhanced
position-sensitive avalanche photodiodes |
| Authors: |
Myers, Richard A.; Farrell, Richard; Robertson, Frank; Carey, James E.; Mazur, Eric |
| Publication: |
Infrared Systems
and Photoelectronic Technology III. Edited by
Dereniak, Eustace L.; Hartke, John P.; LeVan,
Paul D.; Longshore, Randolph E.; Sood, Ashok
K. Proceedings of the SPIE, Volume 7055, pp.
70550L-70550L-12 (2008). (SPIE
Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
SPIE |
| Abstract
Copyright: |
(c) 2008: SPIE--The
International Society for Optical Engineering.
Downloading of the abstract is permitted for
personal use only. |
| DOI: |
10.1117/12.794866 |
| Bibliographic
Code: |
2008SPIE.7055E..13M |
Abstract:
A laser processing method was used to microstructure
the surface of position-sensitive silicon avalanche photodiodes
(PSAPDs) and enhance their near-infrared response. Following
laser microstructuring and high-temperature annealing,
experiments were performed on PSAPDs to determine their
performance at 1064 nm. As a result of this processing
method, we fabricated APDs with quantum efficiencies
as high as 58% at 1064 nm. The enhanced near-infrared
response has now been realized in both lateral effect
and quadrant-type PSAPDs without altering their electronic
noise, avalanche gain or position resolution. A near-infrared-enhanced
PSAPD module with temperature control and position output
was assembled and tested.
| Title: |
Temperature dependence
of the emissivity of platinum in the IR |
| Authors: |
Deemyad, Shanti; Silvera, Isaac F. |
| Affiliation: |
Lyman Laboratory
of Physics, Harvard University, Cambridge, Massachusetts
02138, USA |
| Publication: |
Review of Scientific
Instruments, Volume 79, Issue 8, pp. 086105-086105-2
(2008). (RScI
Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
AIP |
| Keywords: |
emissivity, infrared
spectra, platinum, pyrometers |
| Abstract
Copyright: |
(c) 2008: American
Institute of Physics |
| DOI: |
10.1063/1.2966394 |
| Bibliographic
Code: |
2008RScI...79h6105D |
Abstract:
The accuracy of temperature determination by fitting
the spectral irradiance to a Planck curve depends on
knowledge of the emissivity at all temperatures and pressures
of interest within a spectral region. Here, the emissivity
of platinum is measured in the near infrared as a function
of temperature. In the wavelength range of study and
the temperature range of 650-1100 K, we find the emissivity
to be independent of temperature to within experimental
error. This result should lead to improved accuracy of
temperature measurement by optical pyrometry where platinum
is used as a thermal emitter.
Abstract:
The drying dynamics in three dimensional porous media
are studied with confocal microscopy. We observe abrupt
air invasions in size from single particle to hundreds
of particles. We show that these result from the strong
flow from menisci in large pores to menisci in small
pores during drying. This flow causes air invasions to
start in large menisci and subsequently spread throughout
the entire system. We measure the size and structure
of the air invasions and show that they are in accord
with invasion percolation. By varying the particle size
and contact angle we unambiguously demonstrate that capillary
pressure dominates the drying process.
| Title: |
Study of B Meson Decays
with Excited η and η' Mesons |
| Authors: |
Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prudent, X.; Tisserand, V.; Zghiche, A.; Garra Tico, J.;... Morii, M.;...;
and 563 coauthors. |
| Publication: |
Physical Review Letters,
vol. 101, Issue 9, id. 091801 (PhRvL
Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
APS |
| Abstract Copyright: |
(c) 2008: The American
Physical Society |
| DOI: |
10.1103/PhysRevLett.101.091801 |
| Bibliographic
Code: |
2008PhRvL.101i1801A |
Abstract: Using 383×10
6 B&Bmacr;
pairs from the BABAR data sample, we report results for
branching fractions of six charged B-meson decay modes,
where a charged kaon recoils against a charmless resonance
decaying to K&Kmacr;
* or ηππ final states
with mass in the range (1.2–1.8)GeV/c
2. We
observe a significant enhancement at the low K&Kmacr;
* invariant
mass which is interpreted as B
+→η(1475)K
+,
find evidence for the decay B
+→η(1295)K
+,
and place upper limits on the decays B
+→η(1405)K
+,
B
+→f
1(1285)K
+, B
+→f
1(1420)K
+,
and B
+→ϕ(1680)K
+.
| Title: |
Publisher's Note: Search
for Pair Production of Scalar Top Quarks Decaying
to a τ Lepton and a b Quark in p&pmacr; Collisions
at s=1.96TeV [Phys. Rev. Lett. 101, 071802 (2008)] |
| Authors: |
Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, M. G.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.;... Franklin, M.;
... Guimaraes da Costa, J....;
and 609 coauthors. |
| Publication: |
Physical Review Letters,
vol. 101, Issue 8, id. 089901 (PhRvL
Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
APS |
| Abstract Copyright: |
(c) 2008: The American
Physical Society |
| DOI: |
10.1103/PhysRevLett.101.089901 |
| Bibliographic
Code: |
2008PhRvL.101h9901A |
Abstract: Not Available
| Title: |
Observation of Y(3940)→J/ψω
in B→J/ψωK at BABAR |
| Authors: |
Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prudent, X.; Tisserand, V.; Zghiche, A.; Garra Tico, J.;... Morii, M.;...;
and 561 coauthors. |
| Publication: |
Physical Review Letters,
vol. 101, Issue 8, id. 082001 (PhRvL
Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
APS |
| Abstract Copyright: |
(c) 2008: The American
Physical Society |
| DOI: |
10.1103/PhysRevLett.101.082001 |
| Bibliographic
Code: |
2008PhRvL.101h2001A |
Abstract: We present a study
of the decays B
0,+→J/ψωK
0,+ using
383×10
6 B&Bmacr; events obtained with
the BABAR detector at PEP-II. We observe Y(3940)→J/ψω,
with mass 3914.6
-3.4+3.8(stat)±2.0(syst)MeV/c
2,
and width 34
-8+12(stat)±5(syst)MeV.
The ratio of B
0 and B
+ decay to
YK is 0.27
-0.23+0.28(stat)
-0.01+0.04(syst),
and the relevant B
0 and B
+ branching
fractions are reported.
| Title: |
Measurements of B→{π,η,η'}lνl Branching
Fractions and Determination of |Vub|
with Semileptonically Tagged B Mesons |
| Authors: |
Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Garra Tico, J.;... Morii, M.;...;
and 527 coauthors. |
| Publication: |
Physical Review Letters,
vol. 101, Issue 8, id. 081801 (PhRvL
Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
APS |
| Abstract Copyright: |
(c) 2008: The American
Physical Society |
| DOI: |
10.1103/PhysRevLett.101.081801 |
| Bibliographic
Code: |
2008PhRvL.101h1801A |
Abstract: We report measurements
of branching fractions for the decays B→Pℓν
ℓ,
where P are the pseudoscalar charmless mesons π
-,
π
0, η and η
', based on 348fb
-1 of
data collected with the BABAR detector, using B
0 and
B
+ mesons found in the recoil of a second
B meson decaying as B→D
(*)ℓν
ℓ.
Assuming isospin symmetry, we combine pionic branching
fractions to obtain B(B
0→π
-ℓ
+ν
ℓ)=(1.54±0.17
(stat)±0.09
(syst))×10
-4;
we find 3.2σ evidence of the decay B
+→ηℓ
+ν
ℓ and
measure its branching fraction to be (0.64±0.20
(stat)±0.03
(syst))×10
-4,
and determine B(B
+→η
'ℓ
+ν
ℓ)<0.47×10
-4 to
90% confidence level. Using partial branching fractions
for the pionic decays in ranges of the momentum transfer
and a variety of form factor calculation, we obtain values
of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix
element |V
ub| in ranging from 3.6×10
-3 to
4.1×10
-3.
| Title: |
Suppression of Inelastic
Collisions Between Polar Molecules With a Repulsive
Shield |
| Authors: |
Gorshkov, A. V.; Rabl, P.; Pupillo, G.; Micheli, A.; Zoller, P.; Lukin, M. D.; Büchler, H. P. |
| blication: |
Physical Review Letters,
vol. 101, Issue 7, id. 073201 (PhRvL
Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
APS |
| Abstract
Copyright: |
(c) 2008: The American
Physical Society |
| DOI: |
10.1103/PhysRevLett.101.073201 |
| Bibliographic
Code: |
2008PhRvL.101g3201G |
Abstract:
We propose and analyze a technique that allows one to
suppress inelastic collisions and simultaneously enhance
elastic interactions between cold polar molecules. The
main idea is to cancel the leading dipole-dipole interaction
with a suitable combination of static electric and microwave
fields in such a way that the remaining van der Waals-type
potential forms a three-dimensional repulsive shield.
We analyze the elastic and inelastic scattering cross
sections relevant for evaporative cooling of polar molecules
and discuss the prospect for the creation of stable crystalline
structures.
| Title: |
Search for Pair Production
of Scalar Top Quarks Decaying to a τ Lepton and
a b Quark in p&pmacr; Collisions at s=1.96TeV |
| Authors: |
Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, M. G.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.;... Franklin, M.;
... Guimaraes da Costa, J....;
and 609 coauthors. |
| Publication: |
Physical Review Letters,
vol. 101, Issue 7, id. 071802 (PhRvL
Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
APS |
| Abstract Copyright: |
(c) 2008: The American
Physical Society |
| DOI: |
10.1103/PhysRevLett.101.071802 |
| Bibliographic
Code: |
2008PhRvL.101g1802A |
Abstract: We search for
pair production of supersymmetric top quarks (&ttilde;
1),
followed by R-parity violating decay
&ttilde;
1→τb with a branching ratio β,
using 322pb
-1 of p&pmacr; collisions at
s=1.96TeV collected by the upgraded Collider Detector
at Fermilab. Two candidate events pass our final selection
criteria, consistent with the standard model expectation.
We set upper limits on the cross section σ(&ttilde;
1&ttilde;¯
1)×β
2 as
a function of the top-squark mass m(&ttilde;
1).
Assuming β=1, we set a 95% confidence level limit m(&ttilde;
1)>153GeV/c
2.
The limits are also applicable to the case of a third-generation
scalar leptoquark (LQ
3) decaying LQ
3→τb.
| Title: |
Improved measurement
of the CKM angle γ in B∓→D(*)K(*)∓ decays
with a Dalitz plot analysis of D decays to KS0π+π- and
KS0K+K- |
| Authors: |
Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Garra Tico, J.;... Morii, M.;...;
and 534 coauthors. |
| Publication: |
Physical Review D,
vol. 78, Issue 3, id. 034023 (PhRvD
Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
APS |
| Abstract Copyright: |
(c) 2008: The American
Physical Society |
| DOI: |
10.1103/PhysRevD.78.034023 |
| Bibliographic
Code: |
2008PhRvD..78c4023A |
Abstract: We report on an
improved measurement of the Cabibbo-Kobayashi-Maskawa
CP-violating phase γ through a Dalitz plot analysis of
neutral D meson decays to K
S0π
+π
- and
K
S0K
+K
- produced
in the processes B
∓→DK
∓, B
∓→D
*K
∓ with
D
*→Dπ
0, Dγ, and B
∓→DK
*∓ with
K
*∓→K
S0π
∓.
Using a sample of 383×10
6 B&Bmacr; pairs
collected by the BABAR detector, we measure γ=(76±22±5±5)°
(mod 180°), where the first error is statistical, the
second is the experimental systematic uncertainty, and
the third reflects the uncertainty on the description
of the Dalitz plot distributions. The corresponding 2-standard-deviation
region is 29°<γ<122°. This result has a significance
of direct CP violation (γ≠0) of 3.0 standard deviations.
| Title: |
Search for heavy, long-lived
neutralinos that decay to photons at CDF II using
photon timing |
| Authors: |
Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, M. G.; González, B. Álvarez; Amerio, S.; Amidei, D.; Anastassov, A.;
... Franklin, M.;
... Guimaraes da Costa, J....;
and 590 coauthors. |
| Publication: |
Physical Review D,
vol. 78, Issue 3, id. 032015 (PhRvD
Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
APS |
| Abstract Copyright: |
(c) 2008: The American
Physical Society |
| DOI: |
10.1103/PhysRevD.78.032015 |
| Bibliographic
Code: |
2008PhRvD..78c2015A |
Abstract: We present the
results of the first hadron collider search for heavy,
long-lived neutralinos that decay via χ˜
10→γ&Gtilde;
in gauge-mediated supersymmetry breaking models. Using
an integrated luminosity of 570±34pb
-1 of
p&pmacr; collisions at s=1.96TeV, we select γ+jet+missingtransverseenergy
candidate events based on the arrival time of a high-energy
photon at the electromagnetic calorimeter as measured
with a timing system that was recently installed on the
CDF II detector. We find 2 events, consistent with the
background estimate of 1.3±0.7 events. While our search
strategy does not rely on model-specific dynamics, we
set cross section limits and place the world-best 95%
C.L. lower limit on the χ˜
10 mass
of 101GeV/c
2 at τ
χ˜10=5ns.
| Title: |
Search for standard
model Higgs boson production in association with
a W boson at CDF |
| Authors: |
Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, M. G.; González, B. Álvarez; Amerio, S.; Amidei, D.; Anastassov, A.;
... Franklin, M.;
... Guimaraes da Costa, J....;
and 587 coauthors. |
| Publication: |
Physical Review D,
vol. 78, Issue 3, id. 032008 (PhRvD
Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
APS |
| Abstract Copyright: |
(c) 2008: The American
Physical Society |
| DOI: |
10.1103/PhysRevD.78.032008 |
| Bibliographic
Code: |
2008PhRvD..78c2008A |
Abstract: We present a search
for standard model Higgs boson production in association
with a W boson in proton-antiproton collisions (p&pmacr;→W
±H→ℓνb&bmacr;)
at a center of mass energy of 1.96 TeV. The search employs
data collected with the CDF II detector which correspond
to an integrated luminosity of approximately 1fb
-1.
We select events consistent with a signature of a single
lepton (e
±/μ
±), missing transverse
energy, and two jets. Jets corresponding to bottom quarks
are identified with a secondary vertex tagging method
and a neural network filter technique. The observed number
of events and the dijet mass distributions are consistent
with the standard model background expectations, and
we set 95% confidence level upper limits on the production
cross section times branching ratio ranging from 3.9
to 1.3 pb for Higgs boson masses from 110 to 150GeV/c
2,
respectively.
| Title: |
Microscopic dynamics
at the glass transition: insights from soft colloidal
dispersions |
| Authors: |
Romeo, G.; Imperiali, L.; Nieves, A. F.; Acierno, D.; Weitz, D. A. |
| Publication: |
IV INTERNATIONAL
CONFERENCE TIMES OF POLYMERS (TOP) AND COMPOSITES.
AIP Conference Proceedings, Volume 1042, pp.
52-54 (2008). (AIPC
Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
AIP |
| Keywords: |
reaction kinetics,
surface chemistry, glass transition, molecular
dynamics method, polymerisation, optical microscopy,
molecular configurations |
| Abstract
Copyright: |
(c) 2008: American
Institute of Physics |
| DOI: |
10.1063/1.2989070 |
| Bibliographic
Code: |
2008AIPC.1042...52R |
Abstract:
We investigate the microscopic dynamics of compressible
colloidal particles as function of concentration through
dynamic light scattering and confocal microscopy experiments.
In analogy with hard sphere (HS) colloidal systems, we
find that the particles display liquid, supercooled liquid
or glassy dynamics, depending on volume fraction. In
the present case, however caging effects are observed
for particle volume fractions higher than one, i.e. when
the particles are compressed. We find that heterogeneous
dynamics, described by a non Gaussian distribution of
the displacements, play a major role in the supercooled
liquid in proximity of the relaxation time.
| Title: |
Quantum optics and
atomic physics using plasmonics |
| Authors: |
Chang, D. E.; Lukin, M. D. |
| Publication: |
Plasmonics: Metallic
Nanostructures and Their Optical Properties VI.
Edited by Stockman, Mark I. Proceedings of the
SPIE, Volume 7032, pp. 70320N-70320N-12 (2008).
(SPIE Homepage) |
| Publication
Date: |
08/2008 |
| Origin: |
SPIE |
| Abstract
Copyright: |
(c) 2008: SPIE--The
International Society for Optical Engineering.
Downloading of the abstract is permitted for
personal use only. |
| DOI: |
10.1117/12.797599 |
| Bibliographic
Code: |
2008SPIE.7032E...7C |
Abstract:
The large field intensities and tight field confinements
that are readily achievable using nanoscale plasmonic
devices offer intriguing new tools for use in quantum
optics, single-photon nonlinear optics, and atomic physics.
We discuss several methods in which plasmonics can be
used to enable the coherent manipulation of single photons
and strong nonlinear interactions between them.
Abstract:
Not Available
Abstract:
Not Available
| Title: |
Geochronology of
the Archean of Australia |
| Authors: |
Nelson, D. R. |
| Publication: |
Australian Journal
of Earth Sciences, vol. 55, issue 6, pp. 779-793 |
| Publication
Date: |
08/2008 |
| Origin: |
CROSSREF |
| DOI: |
10.1080/08120090802094135 |
| Bibliographic
Code: |
2008AuJES..55..779N |
Abstract:
Not Available
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