Korea Institute of Science and Technology Information

About: Korea Institute of Science and Technology Information is a facility organization based out in Daejeon, South Korea. It is known for research contribution in the topics: Gravitational wave & LIGO. The organization has 1152 authors who have published 2319 publications receiving 93849 citations. The organization is also known as: Korea Institute of Science and Technology Information & KISTI.

Observation of new resonant structures in γγ → ωϕ, ϕϕ, and ωω.

Abstract: The processes γγ → ωϕ, ϕϕ, and ωω are measured using an 870 fb(-1) data sample collected with the Belle detector at the KEKB asymmetric-energy e+ e- collider. Production of vector meson pairs is clearly observed and their cross sections are measured for masses that range from threshold to 4.0 GeV. In addition to signals from well established spin-zero and spin-two charmonium states, there are resonant structures below charmonium threshold, which have not been previously observed. We report a spin-parity analysis for the new structures and determine the products of the η(c), χ(c0), and χ(c2) two-photon decay widths and branching fractions to ωϕ, ϕϕ, and ωω.

Abrupt spin transition in a modified-terpyridine cobalt(ii) complex with a highly-distorted [CoN6] core

Abstract: The cobalt(ii) complex incorporating π-conjugated substituent, [Co(Naph-C2-terpy)2](BF4)2 (1; Naph-C2-terpy = 4'-(2-naphthoxy(ethoxy))-2,2':6',2''-terpyridine), exhibits an abrupt spin transition (ST) behavior (cooperative factor C = 0.91) while its solvated product, 1·2MeOH, shows gradual spin crossover (SCO) behavior (C = 0.49). Single crystal X-ray structural analyses demonstrated that the octahedral coordination core [CoN6] in 1 shows larger distortion in both high-spin and low-spin states than solvated 1·2MeOH or another two derivatives, [Co(R-terpy)2](BF4)2 (R = 2-naphthyl (2), 9-anthracenyl (3)). The respective distortion parameters (Σ) are compared with those for previously reported SCO cobalt(ii) compounds. The highly-distorted [CoN6] core in 1 (Σ = 126 in the HS state and 101.6 in the LS state) was stabilized by strong intermolecular interactions and observed an abrupt ST behaviour.

Azimuthally Differential Pion Femtoscopy in Pb-Pb Collisions at sNN =2.76 TeV

Abstract: We present the first azimuthally differential measurements of the pion source size relative to the second harmonic event plane in Pb-Pb collisions at a center-of-mass energy per nucleon-nucleon pair of √sNN = 2.76 TeV. The measurements have been performed in the centrality range 0%-50% and for pion pair transverse momenta 0.2 < kT < 0.7 GeV/c. We find that the Rside and Rout radii, which characterize the pion source size in the directions perpendicular and parallel to the pion transverse momentum, oscillate out of phase, similar to what was observed at the Relativistic Heavy Ion Collider. The final-state source eccentricity, estimated via Rside oscillations, is found to be significantly smaller than the initial-state source eccentricity, but remains positive - indicating that even after a stronger expansion in the in-plane direction, the pion source at the freeze-out is still elongated in the out-of-plane direction. The 3 + 1D hydrodynamic calculations are in qualitative agreement with observed centrality and transverse momentum Rside oscillations, but systematically underestimate the oscillation magnitude.

Measurement of the branching fraction and CP asymmetry in B0 → π0π0 decays, and an improved constraint on ϕ2

Abstract: We measure the branching fraction and CP violation asymmetry in the decay B-0 -> pi(0)pi(0), using a data sample of 752 x 10(6) B (B) over bar pairs collected at the Y(4S) resonance with the Belle detector at the KEKB e(+)e(-) collider. The obtained branching fraction and direct CP asymmetry are B(B -> pi(0)pi(0)) = [1.31 +/- 0.19(stat) +/- 0.19(syst)] x 10(-6) and A(CP) = +0.14 +/- 0.36(stat) +/- 0.10(syst), respectively. The signal significance, including the systematic uncertainty, is 6.4 standard deviations. We combine these results with Belle's earlier measurements of B-0 -> pi(+)pi(-) and B-+/- -> pi(+/-)pi(0) to exclude the CP-violating parameter phi(2) from the range 15.5 degrees < phi(2) < 75.0 degrees at 95% confidence level.

Understanding science and technology information users through transaction log analysis

Abstract: Purpose – This study seeks to provide insight into user interaction with a web‐based information system of science and technology, as extending the large‐scale research of search queries. Ultimately, this study aims to gain knowledge of user behavior in order to improve the IR system for the users.Design/methodology/approach – The paper quantitatively analyzed queries submitted to a web‐based IR system in science and technology. The data were collected in a full one‐year period beginning on Friday, 1 January 2010 through on Friday, 31 December 2010. More than 7,240,000 queries and 20,700,000 records were quantitatively analyzed in this period for this study.Findings – In general, queries themselves tend to be short and simple (1.4 terms) for the web‐based IR system in science and technology. This indicates that users tend to invest a minimum of effort (cognitive and physical) and time in structuring their information needs to look for information on the system. However, user sessions on the IR system are ...