1 / 47

New CHIPS elastic cross-sections

Mikhail Kosov , Hadronic meeting,26/02/10. New CHIPS elastic cross-sections. Introduction. Inelastic pA cross-sections have been tuned by s in (“ex”)= s tot (ex)- s el (CHIPS).

yelena
Télécharger la présentation

New CHIPS elastic cross-sections

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Mikhail Kosov, Hadronic meeting,26/02/10 New CHIPS elastic cross-sections

  2. Introduction Inelastic pA cross-sections have been tuned by sin(“ex”)=stot(ex)-sel(CHIPS). At some energies sin(“ex”) differs from direct sin(ex). The CHIPS sel(NA) approximation must be improved there. The next step is to improve the CHIPS sel(hA) CHIPS approximation, using sel(“ex”)=stot(ex)-sin(CHIPS) “data” Use CHIPS Glauber calculations of sel

  3. n n n It means that the elastic nPb CHIPS cross-sections must be improved

  4. How to use the stot=sin+sel CHIPS test tool • Ideally sin(CHIPS) must coincide with stot-sel(CHIPS), as this is shown for the neutron-aluminium interactions. • This is not true for neutron-lead interactions for p<0.3. • In this presentation cleaning up of sel of pA interaction is presented: a new analytics 2D-functionsel(p,A) for pA. • As a next step, CHIPS 2D-functions sel(p,A) for hA are implemented in Geant4 and compared with other G4 sel. • An upgrade for neutron-nuclear elastic is started. At low energies it demands individual fit for 388 target-isotope. • New CHIPS sel(nA) improves both HP & LHEP (2 in 1). • A G4Had wrapper for the CHIPS elastic cross-sections is implemented to be used by other G4 hadronic processes.

  5. A bug?

  6. CHIPS parameterization of sel for hA • CHIPS calculation: sel=∫(1-e-sT(b)/2)2d2b (---------) • Fortunately, at low energies there are pA data. • The CHIPS sel(pA) function is good in D-region • The Barashenkov’s sel(pA) fit does not look much better than the LHEP (GEISHA) fit (all energies) • The threshold of the Glauber-Gribov and LHEP fits is too low and BGG has too high thresholds • In the GeV region all G4 fits (other than CHIPS) have strange position of the cross-section maxima • The CHIPS pA fit is significantly below other G4 fits, what can a bit accelerate CHIPS calculations

  7. New CHIPS nA elastic for light nuclei • New CHIPS nA Elastic is based on • Interaction length fit (1/v part) • Interaction radius fit (constant part) • Absorptive band (below 20 MeV=200 MeV/c) • Coincidence with new high enrgy pA CHIPS elastic • It is not that detailed as the tabulated HP fit, but it covers more isotopes and fits updated ENDF • Big discrepancy with LHEP at high energies • New CHIPS nA elastic cross-sections are covering both low and high energies, do not have any tables and works faster than the HP+LHEP

  8. 53 days

  9. Conclusion • New CHIPS elastic pA fit is better than old one • At low energies there are big uncertainties in sel • The best existing (not CHIPS) approximation is the Barashenkov fit (only pA & pA) • The Glauber-Gribov fit is not reliable at low E • BGG has too high threshold and, probably, bugs. • The pA ENDF/B VII is too low, but the maxima positions coincide with the integrated CHIPS fit • CHIPS hA fit is usually below other G4 fits, but at low E CHIPS electromagnetic must be added • New low energy nA is competitive with HP and more detailed, and at high E is better than LHEP

  10. Thank you Backup slides following

More Related