Analyzing power in nucleon-deuteron scattering and three-nucleon forces

Three-nucleon forces have been considered to be one possibility to resolve the well-known discrepancy between experimental values and theoretical calculations of the nucleon analyzing power in low energy nucleon-deuteron scattering. In this Rapid Communication, we investigate the possible effects of two-pion exchange three-nucleon forces on the analyzing power and the differential cross section. We found that the reason for different effects on the analyzing power by different three-nucleon forces found in previous calculations is related to the existence of the contact term. Effects of some variations of two-pion exchange three-nucleon forces are investigated. Also, an expression for the measure of the nucleon analyzing power with quartet P-wave phase shifts is presented.