The invariant differential cross section for inclusive neutral-pion production in p+p collisions at roots=200 GeV has been measured at midrapidity (eta<0.35) over the range 1<p(T)less than or similar ...to14 GeV/c by the PHENIX experiment at the Relativistic Heavy Ion Collider. Predictions of next-to-leading order perturbative QCD calculations are consistent with these measurements. The precision of our result is sufficient to differentiate between prevailing gluon-to-pion fragmentation functions.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
A new pentanuclear "cylinder"-like cobalt(
ii
) phenylsilsesquioxane (PhSiO
1.5
)
10
(CoO)
5
(NaOH) exhibits a slow relaxation of the magnetization and a high catalytic activity and stereoselectivity ...in the oxidation of alkanes and alcohols.
A new pentanuclear "cylinder"-like cobalt(
ii
) phenylsilsesquioxane (PhSiO
1.5
)
10
(CoO)
5
(NaOH) exhibits a slow relaxation of the magnetization and a high catalytic activity and stereoselectivity in the oxidation of alkanes and alcohols.
Transverse single-spin asymmetries to probe the transverse-spin structure of the proton have been measured for neutral pions and nonidentified charged hadrons from polarized proton-proton collisions ...at midrapidity and root s = 200 GeV. The data cover a transverse momentum (pT) range 1.0-5.0 GeV/c for neutral pions and 0.5-5.0 GeV/c for charged hadrons, at a Feynman-x value of approximately zero. The asymmetries seen in this previously unexplored kinematic region are consistent with zero within errors of a few percent. In addition, the inclusive charged hadron cross section at midrapidity from 0.5 < P-T < 7.0 GeV/c is presented and compared to next-to-leading order perturbative QCD ( pQCD) calculations. Successful description of the unpolarized cross section above similar to 2 GeV/c suggests that pQCD is applicable in the interpretation of the asymmetry results in the relevant kinematic range.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
Bose-Einstein correlations of identically charged pion pairs were measured by the PHENIX experiment at midrapidity in Au+Au collisions at roots(NN)=200 GeV. The Bertsch-Pratt radius parameters were ...determined as a function of the transverse momentum of the pair and as a function of the centrality of the collision. Using the standard core-halo partial Coulomb fits, and a new parametrization which constrains the Coulomb fraction as determined from the unlike-sign pion correlation, the ratio R-out/R-side is within 0.8-1.1 for 0.25<<k(T)><1.2 GeV/c. The centrality dependence of all radii is well described by a linear scaling in N-part(1/3), and R-out/R-side for <k(T)>similar to0.45 GeV/c is approximately constant at unity as a function of centrality.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
We report on the yield of protons and antiprotons, as a function of centrality and transverse momentum, in Au+Au collisions at rootS(NN)=200 GeV measured at midrapidity by the PHENIX experiment at ...the BNL Relativistic Heavy Ion Collider. In central collisions at intermediate transverse momenta (1.5<p(T)<4.5 GeV/c) a significant fraction of all produced particles are protons and antiprotons. They show a centrality-scaling behavior different from that of pions. The (p) over bar/pi and p/pi ratios are enhanced compared to peripheral Au+Au, p+p, and e(+)e(-) collisions. This enhancement is limited to p(T)<5 GeV/c as deduced from the ratio of charged hadrons to pi(0) measured in the range 1.5<p(T)<9 GeV/c.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
The Landau level spectroscopy technique has been used to explore the electronic structure of the valence band in a series of p-type HgTe/HgCdTe quantum wells with both normal and inverted ordering of ...bands. We find that the standard axial-symmetric 4-band Kane model, which is nowadays widely applied in physics of HgTe-based topological materials, does not fully account for the complex magneto-optical response observed in our experiments-notably, for the unexpected avoided crossings of excitations and for the appearance of transitions that are electric-dipole forbidden within this model. Nevertheless, reasonable agreement with experiments is achieved when the standard model is expanded to include effects of bulk and interface inversion asymmetries. These remove the axial symmetry, and among other, profoundly modify the shape of valence bands.
A facile and fast enantioselective synthesis of α‐amino acids with high ee values was achieved by the asymmetric alkylation of the glycine derivative 1 under phase‐transfer conditions with (R)‐ or ...(S)‐ 2‐amino‐2′‐hydroxy‐1,1′‐binaphthyl (NOBIN; see scheme). The ee value of the catalyst can be as little as 40 % without decreasing the ee value of the amino acid products. This occurs as a result of a significant positive nonlinear effect in the alkylation reaction.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Titanium complexes 1 derived from chiral salen ligands are highly active precatalysts for the asymmetric addition of trimethylsilyl cyanide to aldehydes and ketones. Based on spectroscopic studies ...and the identification of adducts between complexes 1 and carbonyl compounds or trimethylsilyl cyanide, a catalytic cycle which explains the origin of the asymmetric induction is proposed. Kinetics studies have been carried out, the results of which are consistent with the proposed catalytic cycle.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
PDF
