Abstract
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 summary Title of program: QRAP ( Quasiparticle RAndom Phase approximation) Computers: The code has been created on a PC, but also runs on UNIX or LINUX machines Operating systems: WINDOWS or UNIX Program language used: Fortran-77 Memory required to execute with typical data: 16 Mbytes of RAM memory and 2 MB of hard disk space No. of lines in distributed program, including test data, etc.: ∼ 8000 No. of bytes in distributed program, including test data, etc.: ∼ 256 kB Distribution format: tar.gz Nature 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.
Highlights
The new age of the physics beyond the standard model of electroweak interaction has as one of the most promising pathways the search of neutrino oscillations
Before proceeding we address briefly on the genesis of the quasiparticle RPA (QRPA) and projected QRPA (PQRPA) in a manner appropriate in the present context
A comparison between the QRPA and PQRPA for the same interaction and employing the same model space shows that the projection procedure could be important for medium mass nuclei
Summary
The new age of the physics beyond the standard model of electroweak interaction has as one of the most promising pathways the search of neutrino oscillations. A comparison between the QRPA and PQRPA for the same interaction and employing the same model space shows that the projection procedure could be important for medium mass nuclei Several approximations such as: i) Hybrid Model (HM) [36], ii) QRPA with Skyrme interaction [37], iii) relativistic QRPA (RQRPA) [38], and iv) QRPA and PQRPA with the δ-force [35] yield different results for the neutrino cross section as a function of the neutrino energy. [39,40] with selfconsistent calculations, such as the QRPA, PQRPA and RQRPA, could be enlightening This brief introduction shows: 1) the importance of neutrino– nucleus cross sections for astrophysical purposes, and 2) that these cross sections are strongly correlated with the nuclear structure model employed.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
