1 Atomic Mass Evaluation Meng WANG （王猛） CSNSM-CNRS, France MPIK-Heidelberg, Germany IMP-CAS, China 5 th FCPPL workshop

2 Outline Atomic mass Atomic mass evaluation (AME) Present status of AME

3 Atomic mass Nuclear physics Atomic physics Nuclear astrophysics Atomic energy Fundamental symmetries Metrology ….. Atomic mass Nuclear mass E = mc 2

4 Nuclear physics The NUBASE evaluation of nuclear and decay properties G. Audi et al., Nuclear Physics A 729 (2003) 3–128

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6 shell subshell deformation Nuclear structure

7 Nuclear astrophysics Boundaries enclosing the temperature and neutron density conditions required for an r process to produce a strong A = 80 abundance peak. “Mass measurements beyond the major r-process waiting point 80 Zn” Baruah et al., PRL 101, (2008) Regions in the temperature and density plane where 64Ge is a waiting point (WP) “Direct mass measurements of short-Lived A = 2Z-1 nuclides 63 Ge, 65 As, 67 Se, and 71 Kr and their Impact on nucleosynthesis in the rp process” Tu et al., PRL 106, (2011)

8 Test of the conserved vector current (CVC) hypothesis Test of the unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) matrix

9 Neutrino-less double beta-decay Neutrino: Majorana particle? Q ββ (keV) 48 Ca Ge Se Zr Mo Pd Cd Sn Te Xe Nd List of candidates Accurate Q ββ values are necessary. from Ame

10 Neutrino mass A high-precision Q( 3 H- 3 He)-value is necessary. Fedor Simkovic et al., PHYSICAL REVIEW C 77, (2008) E max -Q β -m ν (eV) Relativistic Kurie plot of the tritium β decay Q β = (83) eV from Ame

11 Mass measurement: inertial mass energy Relative Measurements How are atomic masses measured? Mass ratio M[ 33 S + ]/M[ 32 SH + ] Energy released from neutron capture of 32 S

12 Mass measurements with a storage ring Primary beams: 78 Kr, 58 Ni, 86 Kr… X.L.Tu, H.S.Xu, M.Wang …G.Audi et al., Phys.Rev.Lett. 106, (2011) X.L.Tu, M.Wang, …G.Audi et al., NIM A 654, 213 (2011)

13 What do we do? Atomic mass evaluation So……

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15 The AME2003 A.H. Wapstra, G. Audi, C. Thibault, Nucl. Phys. A 729 (2003) 129 Atomic Mass Evaluation Atomic masses are extracted from the complex network of string tensions.

16 NUBASE: Evaluation of nuclear properties

17 The AME procedure Experimental Data Collection and Evaluation Treatment of Data Least Squares Method Estimates from mass surface topology (EMT) Comparison with a smooth function Requires a collaborative effort with theorists. F.R.Xu (Beijing university) and Z.Z.Ren (Nanjing university).

18 50 years of mass evaluation An introduction of the history of atomic masses : Georges Audi “The history of nuclidic masses and of their evaluation” International Journal of Mass Spectrometry 251 (2006) 85–94 Early 1950’s, relations overdetermine masses Aaldert H. Wapstra -- least-squares method First evaluation using this method 1955 Ame1961, Ame1964, Ame1971, Ame1977 Ame1983, Ame1993, Ame2003, Ame2012

Masses 2416 known ground state 232 known isomers 1063 estimated Statistics Present status Input data input equations 5275 mass spectrometry 8534 reactions

20 Mass measurement: inertial mass energy Relative Measurements How are atomic masses measured? Mass ratio M[ 33 S + ]/M[ 32 SH + ] Energy released from neutron capture of 32 S 32 S + n - 33 S = (33) keV 33 S- ( 32 S + H) = (30) μu

Masses 2416 known ground state 232 known isomers 1063 extrapolated Statistics Present status Input data input equations 5275 mass spectrometry 8534 reactions 33 S- ( 32 S + H) = (30) μu 32 S + n - 33 S = (33) keV

23 New challenges Correlations ……

24 Atomic mass evaluation 1 - prepare and publish AME 2012 (following 2003, 1993 and 1983) 2 - transfer responsibility of AME to IMP-Lanzhou. AME2012 will be published in December IMP-LanzhouCSNSM-Orsay. November 2008, MOU: ~1000pages, 2000 copies If financally supported, 5000 copies of booklet

25 The AME collaboration Coordinator Georges Audi a Contributors Meng Wang a,b,e, Berndt Pfeiffer c, Filip Kondev d, Marion MacCormick f, Jean Blachot a, Xing Xu a,b a.CSNSM-Orsay b.IMP-Lanzhou c.GSI-Darmstadt d.ANL-Argonne e.MPIK-Heildelberg f.IPN-Orsay

26 From PICS to LIA The AME project has strong support from the IN2P3 by a Programme International de Collaboration Scientifique (PICS) for Next step, in the form of a Laboratoire International Associé (LIA) for the AME + NUBASE for the prediction of masses Predictions will cover our estimates from the mass surface topology (EMT), and models from the Universities of Beijing (Beida) and Nanjing.

27 Thank you!