A Fast Convolution Fitting Method for γ Energy Spectrum
This paper present a fast convolution method to be used in fitting the γ spectrum of scintillation crystal PbWO 4 and gives the light yeildof the crystal. It replaces the time costing convolution calculation with a seriesrecursion, which greatly improves the speed of fitting with little loss of preciseness.
We describe preliminary results from an effort to quantify the uncertainties in parton distribution functions and the resulting uncertainties in predicted physical quantities. The production cross section of the $W$ boson is given as a first example. Constraints due to the full data sets of the CTEQ global analysis are used in this study. Two complementary approaches, based on the Hessian and the Lagrange multiplier method respectively, are outlined. We discuss issues on obtaining meaningful uncertainty estimates that include the effect of correlated experimental systematic uncertainties and illustrate them with detailed calculations using one set of precision DIS data.