Detailed analysis of excited-state systematics in a lattice QCD calculation of gA

Excited state contamination remains one of the most challenging sources of systematic uncertainty to control in lattice QCD calculations of nucleon matrix elements and form factors: early time separations are contaminated by excited states and late times suffer from an exponentially bad signal-to-noise problem. High-statistics calculations at large time separations 1 fm are commonly used to combat these issues. In this work, focusing on gA, we explore the alternative strategy of utilizing a large number of relatively low-statistics calculations at short to medium time separations (0.2-1 fm), combined with a multistate analysis. On an ensemble with a pion mass of approximately 310 MeV and a lattice spacing of approximately 0.09 fm, we find this provides a more robust and economical method of quantifying and controlling the excited state systematic uncertainty. A quantitative separation of various types of excited states enables the identification of the transition matrix elements as the dominant contamination. The excited state contamination of the Feynman-Hellmann correlation function is found to reduce to the 1% level at approximately 1 fm while, for the more standard three-point functions, this does not occur until after 2 fm. Critical to our findings is the use of a global minimization, rather than fixing the spectrum from the two-point functions and using them as input to the three-point analysis. We find that the ground state parameters determined in such a global analysis are stable against variations in the excited state model, the number of excited states, and the truncation of early-time or late-time numerical data

Gas Transfer at Water Surfaces 2010

PrefaceSection 1: Interfacial Turbulence and Air-Water Scalar TransferJ. Hunt, S. Belcher, D. Stretch, S. Sajjadi, J. Clegg [1]S.A. Kitaigorodskii [13]S.A. Kitaigorodskii [29]Y. Toba [38]D. Turney, S. Banerjee [51]J.G. Janzen, H.E. Schulz, G.H. Jirka [65]S. Komori, R. Kurose, N. Takagaki, S. Ohtsubo, K. Iwano, K. Handa, S. Shimada [78]J. Beya, W. Peirson, M. Banner [90]S. Mizuno [104]M. Sanjou, I. Nezu, A. Toda [119]M. Sanjou, I. Nezu, Y. Akiya [129]K. Takehara, Y. Takano, T.G. Etoh [138]G. Caulliez [151]Section 2: Numerical Studies on Interfacial Turbulence and Scalar TransferL.-P. Hung, C.S. Garbe, W.-T. Tsai [165]A. E. Tejada-Martínez, C. Akan, C.E. Grosch [177]W.-T. Tsai, L.-P. Hung [193]P.G. Jayathilake, B.C. Khoo, Zhijun Tan [200]H.E. Schulz, A.L.A. Simões, J.G. Janzen [208]Section 3: Bubble-Mediated Scalar TransferD.P. Nicholson, S.R. Emerson, S. Khatiwala, R.C. Hamme [223]W. Mischler, R. Rocholz, B. Jähne [238]R. Patro, I. Leifer [249]K. Loh, K.B. Cheong, R. Uittenbogaard [262]N. Mori, S. Nakagawa [273]Section 4: Effects of Surfactants and Molecular Diffusivity on Turbulence and Scalar TransferA. Soloviev, S. Matt, M. Gilman, H. Hühnerfuss, B. Haus, D. Jeong, I. Savelyev, M. Donelan [285]S. Matt, A. Fujimura, A. Soloviev, S.H. Rhee [299]P. Vlahos, E.C. Monahan, B.J.Huebert, J.B. Edson [313]K.E. Richter, B. Jähne [322]X. Yan, W.L. Peirson, J.W. Walker, M.L. Banner [333]Section 5: Field MeasurementsP.M. Orton, C.J. Zappa, W.R. McGillis [343]U.Schimpf, L. Nagel, B. Jähne [358]C.L. McNeil, E.A. D'Asaro, J.A. Nystuen [368]D. Turk, B. Petelin, J.W. Book [377]M. Ribas-Ribas, A. Gómez-Parra, J.M. Forja [394]A. Rutgersson, A.-S. Smedman, E. Sahlée [406]H. Pettersson, K. K. Kahma, A. Rutgersson, M. Perttilä [420]Section 6: Global Air-Sea CO2 FluxesR. Wanninkhof, G.-H. Park, D.B. Chelton, C.M. Risien [431]N. Suzuki, S. Komori, M.A. Donelan [445]Y. Suzuki, Y. Toba [452]M.T. Johnson, C. Hughes, T.G. Bell, P.S. Liss [464]Section 7: Advanced Measuring TechniquesO. Tsukamoto, F. Kondo [485]R. Rocholz, S. Wanner, U. Schimpf, B. Jähne [496]B.C.G. Gonzalez, A.W. Lamon, J.G. Janzen, J.R. Campos, H.E. Schulz [507]E. Sahlée, K. Kahma, H. Pettersson, W.M. Drennan [516]D. Kiefhaber, R. Rocholz, G. Balschbach, B. Jähne [524]C.S. Garbe, A. Heinlein [535]Section 8: Environmental Problems Related to Air-Water Scalar TransferW.L. Peirson, G.A. Lee, C. Waite, P. Onesemo, G. Ninaus [545]Y.J. Choi, A. Abe, K. Takahashi [559]Y. Baba, K. Takahashi [571]R. Onishi, K. Takahashi, S. Komori [582][593]Turbulence and wave dynamics across gas-liquid interfacesThe calculation of the gas transfer between the ocean and atmosphereThe influence of wind wave breaking on the dissipation of the turbulent kinetic energy in the upper ocean and its dependence on the stage of wind wave developmentMarvellous self-consistency inherent in wind waves : Its origin and some items related to air-sea transfersNear surface turbulence and its relationship to air-water gas transfer ratesTurbulent gas flux measurements near the air-water interface in an oscillating-grid tankSensible and latent heat transfer across the air-water interface in wind-driven turbulenceRainfall-generated, near-surface turbulenceEffects of the mechanical wave propagating in the wind direction on currents and stresses across the air-water interfaceTurbulent transport in closed basin with wind-induced water wavesPIV measurements of Langumuir circulation generated by wind-induced water wavesStudy of vortices near wind wave surfaces using high-speed video camera and MLSWind wave breaking from micro to macroscaleValidation of Eddy-renewal model by numerical simulationMass transfer at the surface in LES of wind-driven shallow water flow with Langmuir circulationCharacteristics of gas-flux density distribution at the water surfacesNumerical simulation of interfacial mass transfer using the immersed interface methodStatistical approximations in gas-liquid mass transferAn inverse approach to estimate bubble-mediated air-sea gas flux from inert gas measurementsExperimental setup for the investigation of bubble mediated gas exchangeGas transfer velocity of single CO2 bubblesMass transfer across single bubblesAeration of surf zone breaking wavesModification of turbulence at the air-sea interface due to the presence of surfactants and implications for gas exchange. Part I: laboratory experimentModification of turbulence at the air-sea interface due to the presence of surfactants and implications for gas exchange. Part II: numerical simulationsWind-dependence of DMS transfer velocity: Comparison of model with recent southern ocean observationsA laboratory study of the Schmidt number dependency of air-water gas transferOn transitions in the Schmidt number dependency of low solubility gas transfer across air-water interfacesAn autonomous self-orienting catamaran (SOCa) for measuring air-water fluxes and forcingThe 2009 SOPRAN active thermography pilot experiment in the Baltic SeaObservations of air-sea exchange of N2 and O2 during the passage of Hurricane Gustav in the Gulf of Mexico during 2008The effect of high wind Bora events on water pCO2 and CO2 exchange in the coastal Northern AdriaticSeasonal sea-surface CO2 fugacity in the north-eastern shelf of the Gulf of Cádiz (southwest Iberian Peninsula)Including mixed layer convection when determining air-sea CO2 transfer velocityAir-sea carbon dioxide exchange during upwellingImpact of small-scale variability on air-sea CO2 fluxesThe effect of wind variability on the air-sea CO2 gas flux estimationFuture global mapping of air-sea CO2 flux by using wind and wind-wave distribution of CMIP3 multi-model ensembleA Rumsfeldian analysis of uncertainty in air-sea gas exchangeAccurate measurement of air-sea CO2 flux with open-path Eddy-CovarianceCombined Visualization of wind waves and water surface temperatureMicroscopic sensors for oxygen measurement at air-water interfaces and sediment biofilmsDamping of humidity fluctuations in a closed-path systemImproved Optical Instrument for the Measurement of Water Wave Statistics in the FieldFriction Velocity from Active Thermography and Shape AnalysisEvaporation mitigation by storage in rock and sandDevelopment of oil-spill simulation system based on the global ocean-atmosphere modelStructure variation dependence of tropical squall line on the tracer advection scheme in cloud-resolving modelHigh-resolution simulations for turbulent clouds developing over the oceAuthor Inde