Analytical computation of process noise matrix in Kalman filter for fitting curved tracks in magnetic field within dense, thick scatterersKolahal Bhattacharya, Sudeshna Banerjee and Naba K. MondalEur. Phys. J. C, 76 7 (2016) 382DOI: https://doi.org/10.1140/epjc/s10052-016-4243-1