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.

Measurements of time-dependent CP asymmetries in B→D* π± decays using a partial reconstruction technique

Abstract: We report results on time-dependent CP asymmetries in B -> D*(-/+)pi(+/-) decays based on a data sample containing 657 x 10(6) B (B) over bar pairs collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider at the Y(4S) resonance. We use a partial reconstruction technique, wherein signal B -> D*(-/+)pi(+/-) events are identified using information only from the fast pion from the B decay and the slow pion from the subsequent decay of the D*(-/+), where the former (latter) corresponds to D*(+)(D*(-)) final states. We obtain CP violation parameters S+ = +0.061 +/- 0.018 (stat) +/- 0.012 (syst) and S- = +0.031 +/- 0.019 (stat) +/- 0.015 (syst).

Production of pi(0) and eta mesons up to high transverse momentum in pp collisions at 2.76 TeV

Abstract: The invariant differential cross sections for inclusive π0 and η mesons at midrapidity were measured in pp collisions at √s = 2.76 TeV for transverse momenta 0.4 < pT < 40 GeV/c and 0.6 < pT < 20 GeV/c, respectively, using the ALICE detector. This large range in pT was achieved by combining various analysis techniques and different triggers involving the electromagnetic calorimeter (EMCal). In particular, a new single-cluster, shower-shape based method was developed for the identification of highpT neutral pions, which exploits that the showers originating from their decay photons overlap in the EMCal. Above 4 GeV/c, the measured cross sections are found to exhibit a similar power-law behavior with an exponent of about 6.3. Next-to-leading-order perturbative QCD calculations differ from the measured cross sections by about 30% for the π0, and between 30–50% for the η meson, while generator-level simulations with PYTHIA 8.2 describe the data to better than 10–30%, except at pT < 1 GeV/c. The new data can therefore be used to further improve the theoretical description of π0 and η meson production.

An Evaluation of the Software System Dependency of a Global Atmospheric Model

Abstract: This study presents the dependency of the simulation results from a global atmospheric numerical model on machines with different hardware and software systems. The global model program (GMP) of the Global/Regional Integrated Model system (GRIMs) is tested on 10 different computer systems having different central processing unit (CPU) architectures or compilers. There exist differences in the results for different compilers, parallel libraries, and optimization levels, primarily a result of the treatment of rounding errors by the different software systems. The system dependency, which is the standard deviation of the 500-hPa geopotential height averaged over the globe, increases with time. However, its fractional tendency, which is the change of the standard deviation relative to the value itself, remains nearly zero with time. In a seasonal prediction framework, the ensemble spread due to the differences in software system is comparable to the ensemble spread due to the differences in initial co...