27,037 research outputs found
M. C. K. Withell
No full text"VX 137097 Sig M.C.K. Withell. 7 Aust. Inf. Bn(A.I.F.) Feb 1942 - Oct 1943 I was there when Australia needed me."VX 137097 Sig M.C.K. Withell. 7th Australian Infantry Battalion (Australian Imperial Forces) February 1942 - October 1943. I was there when Australia needed m
Measurement of the ratio of branching fractions B(B0→K∗0γ )/B(B0s→φγ ) and the directCP asymmetry inB 0→K∗0γ
No full textThe ratio of branching fractions of the radiative B decays B0→K⁎0γ and B0s→ϕγ has been measured using an integrated luminosity of 1.0 fb−1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of s√=7TeV. The value obtained is
B(B0→K⁎0γ)B(B0s→ϕγ)=1.23±0.06(stat.)±0.04(syst.)±0.10(fs/fd),
where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for B(B0→K⁎0γ), the branching fraction B(B0s→ϕγ) is measured to be (3.5±0.4)×10−5.
The direct CP asymmetry in B0→K⁎0γ decays has also been measured with the same data and found to be
ACP(B0→K⁎0γ)=(0.8±1.7(stat.)±0.9(syst.))%.
Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations
K-theory for group C*-algebras
No full textThese notes are based on a lecture course given by the first author in the Sedano Winter School on K-theory held in Sedano, Spain, on January 22-27th of 2007. They aim at introducing K-theory of C*-algebras, equivariant K-homology and KK-theory in the context of the Baum-Connes conjectur
Branching fraction and CP asymmetry of the decays B+→K0Sπ+ and B+→K0SK+
No full textAn analysis of B+ → K0
Sπ+ and B+ → K0
S K+ decays is performed with the LHCb experiment. The pp
collision data used correspond to integrated luminosities of 1 fb−1 and 2 fb−1 collected at centre-ofmass
energies of
√
s = 7 TeV and
√
s = 8 TeV, respectively. The ratio of branching fractions and the
direct CP asymmetries are measured to be B(B+ → K0
S K+
)/B(B+ → K0
Sπ+
) = 0.064 ± 0.009 (stat.) ±
0.004 (syst.), ACP(B+ → K0
Sπ+
) = −0.022 ± 0.025 (stat.) ± 0.010 (syst.) and ACP(B+ → K0
S K+
) =
−0.21 ± 0.14 (stat.) ± 0.01 (syst.). The data sample taken at
√
s = 7 TeV is used to search for
B+
c
→ K0
S K+ decays and results in the upper limit ( fc · B(B+
c
→ K0
S K+
))/( fu · B(B+ → K0
Sπ+
)) <
5.8 × 10−2 at 90% confidence level, where fc and fu denote the hadronisation fractions of a ¯b
quark
into a B+
c or a B+ meson, respectively
First observation of the decay Bs0→K*0K*0
No full textThe first observation of the decay B0s→K∗0K∗0 is reported using 35 pb−1 of data collected by LHCb in proton–proton collisions at a centre-of-mass energy of 7 TeV. A total of 49.8±7.5 B0s→(K+π−)(K−π+) events are observed within ±50 MeV/c2 of the B0s mass and 746 MeV/c2 < mKπ < 1046 MeV/c2, mostly coming from a resonant B0s→K∗0K∗0 signal. The branching fraction and the CP-averaged K∗0 longitudinal polarization fraction are measured to be B(B0s→K∗0K∗0)=(2.81±0.46(stat.)±0.45(syst.)±0.34(fs/ fd))×10−5 and fL =0.31±0.12(stat.)±0.04(syst.)
Search for eta(c) decays into pi pi and K(K)over-bar
No full textUsing 58 million J/psi) events taken with the BESII detector, a search for eta(c) CP violating decays into pi pi and K (K) over bar has been performed. No clear 77, signal is observed, and upper limits for B(eta(c) -> pi pi) and B(eta(c) -> K (K) over bar) are given at the 90% confidence level, B(J/psi -> gamma eta(c)) center dot B(eta(c) -> pi(+)pi(-)) < 1.1 x 10(-5), B(J/psi -> gamma eta(c)) center dot B(eta(c) -> pi(0)pi(0)) < 0.71 x 10(-5), B(J/psi -> gamma(eta c)) center dot B(eta(c) -> K+K-) < 0.96 x 10(-5), and B(J/psi -> gamma eta(c)) center dot B(eta(c) (KSKS0)-K-0) < 0.53 x 10(-5).Physics, Particles & FieldsSCI(E)1ARTICLE2337-3414
Malgrange's vanishing theorem for weakly pseudoconcave CR manifolds
No full textThe authors prove the following CR version of Malgrange's theorem: Assume M is a smooth, non-compact, weakly pseudoconcave CR manifold of type (n,k) of finite kind. Then the highest ∂−M cohomology Hp,n∂−M(M) vanishes for 0≤p≤n+k. This generalises a similar result for real analytic CR manifolds by the third author [in Hyperbolic problems and regularity questions, 137--150, Birkhäuser, Basel, 2007; MR2298789 (2008d:32034)].
Furthermore, they prove the following approximation theorem: If M is as above and U⊂⊂V⊂⊂M are two open sets such that V\sbs UV∖U has no compact connected component then for 0≤p≤n+k the restriction map Zp,n−1(V−)→Zp,n−1(U) has dense image, with respect to the \scr C^\inftyC∞ topology on U. The authors prove the following CR version of Malgrange's theorem: Assume M is a smooth, non-compact, weakly pseudoconcave CR manifold of type (n,k) of finite kind. Then the highest ∂−M cohomology Hp,n∂−M(M) vanishes for 0≤p≤n+k. This generalises a similar result for real analytic CR manifolds by the third author [in Hyperbolic problems and regularity questions, 137--150, Birkhäuser, Basel, 2007; MR2298789 (2008d:32034)].
Furthermore, they prove the following approximation theorem: If M is as above and U⊂⊂V⊂⊂M are two open sets such that V\sbs UV∖U has no compact connected component then for 0≤p≤n+k the restriction map Zp,n−1(V−)→Zp,n−1(U) has dense image, with respect to the \scr C^\inftyC∞ topology on U. The authors prove the following CR version of Malgrange's theorem: Assume M is a smooth, non-compact, weakly pseudoconcave CR manifold of type (n,k) of finite kind. Then the highest ∂−M cohomology Hp,n∂−M(M) vanishes for 0≤p≤n+k. This generalises a similar result for real analytic CR manifolds by the third author [in Hyperbolic problems and regularity questions, 137--150, Birkhäuser, Basel, 2007; MR2298789 (2008d:32034)].
Furthermore, they prove the following approximation theorem: If M is as above and U⊂⊂V⊂⊂M are two open sets such that V\sbs UV∖U has no compact connected component then for 0≤p≤n+k the restriction map Zp,n−1(V−)→Zp,n−1(U) has dense image, with respect to the \scr C^\inftyC∞ topology on U
Comparison of the physical, chemical and electrical properties of ALD Al2O3 on c- and m-plane GaN
No full textThis study compares the physical, chemical and electrical properties of Al[subscript 2]O[subscript 3] thin films deposited on gallium polar c- and nonpolar m -plane GaN substrates by atomic layer deposition (ALD). Correlations were sought between the film's structure, composition, and electrical properties. The thickness of the Al[subscript 2]O[subscript 3] films was 19.2 nm as determined from a Si witness sample by spectroscopic ellipsometry. The gate dielectric was slightly aluminum-rich (Al:O=1:1.3) as measured from X-ray photoelectron spectroscopy (XPS) depth profile, and the oxide-semiconductor interface carbon concentration was lower on c -plane GaN. The oxide's surface morphology was similar on both substrates, but was smoothest on c -plane GaN as determined by atomic force microscopy (AFM). Circular capacitors (50-300 μm diameter) with Ni/Au (20/100 nm) metal contacts on top of the oxide were created by standard photolithography and e-beam evaporation methods to form metal-oxide-semiconductor capacitors (MOSCAPs). The alumina deposited on c -plane GaN showed less hysteresis (0.15 V) than on m -plane GaN (0.24 V) in capacitance-voltage (CV) characteristics, consistent with its better quality of this dielectric as evidenced by negligible carbon contamination and smooth oxide surface. These results demonstrate the promising potential of ALD Al[subscript 2]O[subscript 3] on c -plane GaN, but further optimization of ALD is required to realize the best properties of Al[subscript 2]O[subscript 3] on m -plane GaN
Prompt charm production in pp collisions at √<span style="text-decoration:overline">s</span>=7 TeV
No full textCharm production at the LHC in pp collisions at s√=7 TeV is studied with the LHCb detector. The decays D0→K−π+, D+→K−π+π+, D⁎+→D0(K−π+)π+, D+s→ϕ(K−K+)π+, Λ+c→pK−π+, and their charge conjugates are analysed in a data set corresponding to an integrated luminosity of 15 nb−1. Differential cross-sections dσ/dpT are measured for prompt production of the five charmed hadron species in bins of transverse momentum and rapidity in the region 0<pT<8 GeV/c and 2.0<y<4.5. Theoretical predictions are compared to the measured differential cross-sections. The integrated cross-sections of the charm hadrons are computed in the above pT-y range, and their ratios are reported. A combination of the five integrated cross-section measurements gives
σ(cc¯)pT<8 GeV/c,2.0<y<4.5=1419±12(stat)±116(syst)±65(frag) μb,
where the uncertainties are statistical, systematic, and due to the fragmentation functions
Nicotinic acetylcholine receptors in rat forebrain that bind ¹⁸F-nifene: relating PET imaging, autoradiography, and behavior
No full textNicotinic acetylcholine receptors (nAChRs) in the brain are important for cognitive function; however, their specific role in relevant brain regions remains unclear. In this study, we used the novel compound ¹⁸F-nifene to examine the distribution of nAChRs in the rat forebrain, and for individual animals related the results to behavioral performance on an auditory-cognitive task. We first show negligible binding of ¹⁸F-nifene in mice lacking the β2 nAChR subunit, consistent with previous findings that ¹⁸F-nifene binds to α4β2* nAChRs. We then examined the distribution of ¹⁸F-nifene in rat using three methods: in vivo PET, ex vivo PET and autoradiography. Generally, ¹⁸F-nifene labeled forebrain regions known to contain nAChRs, and the three methods produced similar relative binding among regions. Importantly, ¹⁸F-nifene also labeled some white matter (myelinated axon) tracts, most prominently in the temporal subcortical region that contains the auditory thalamocortical pathway. Finally, we related ¹⁸F-nifene binding in several forebrain regions to each animal's performance on an auditory-cued, active avoidance task. The strongest correlations with performance after 14 days training were found for ¹⁸F-nifene binding in the temporal subcortical white matter, subiculum, and medial frontal cortex (correlation coefficients, r > 0.8); there was no correlation with binding in the auditory thalamus or auditory cortex. These findings suggest that individual performance is linked to nicotinic functions in specific brain regions, and further support a role for nAChRs in sensory-cognitive function.Peer reviewedAuthor's Manuscript is also available open access in PubMed Central: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3292694.This is the peer reviewed version of the following article: Bieszczad, K. M., Kant, R., Constantinescu, C. C., Pandey, S. K., Kawai, H. D., Metherate, R., Weinberger, N. M. and Mukherjee, J. (2012), Nicotinic acetylcholine receptors in rat forebrain that bind 18F-nifene: Relating PET imaging, autoradiography, and behavior. Synapse, 66: 418–434. doi: 10.1002/syn.21530, which has been published in final form at http://dx.doi.org/10.1002/syn.21530. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving
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