QRAP: A numerical code for projected (Q)uasiparticle (RA)ndom (P)hase approximation

A computer code for quasiparticle random phase approximation – QRPA and projected quasiparticle random phase approximation – PQRPA models of nuclear structure is explained in details. The residual interaction is approximated by a simple δ-force. An important application of the code consists in evaluating nuclear matrix elements involved in neutrino–nucleus reactions. As an example, cross sections for 56Fe and 12C are calculated and the code output is explained. The application to other nuclei and the description of other nuclear and weak decay processes are also discussed.Program summaryTitle of program: QRAP (Quasiparticle RAndom Phase approximation)Computers: The code has been created on a PC, but also runs on UNIX or LINUX machinesOperating systems: WINDOWS or UNIXProgram language used: Fortran-77Memory required to execute with typical data: 16 Mbytes of RAM memory and 2 MB of hard disk spaceNo. of lines in distributed program, including test data, etc.: ∼ 8000No. of bytes in distributed program, including test data, etc.: ∼ 256 kBDistribution format: tar.gzNature of physical problem: The program calculates neutrino– and antineutrino–nucleus cross sections as a function of the incident neutrino energy, and muon capture rates, using the QRPA or PQRPA as nuclear structure models.Method of solution: The QRPA, or PQRPA, equations are solved in a self-consistent way for even–even nuclei. The nuclear matrix elements for the neutrino–nucleus interaction are treated as the beta inverse reaction of odd–odd nuclei as function of the transfer momentum.Typical running time: ≈ 5 min on a 3 GHz processor for Data set 1.