NOW 2006 Recent developments in Double Beta Decay Fedor Šimkovic Conca Specchiulla, September 9-16, 2006 Recent developments in Double Beta Decay Fedor Šimkovic Comenius University, Bratislava 11/17/2018 Fedor Simkovic

Bosonic n and 2nbb-decay Conclusions OUTLINE Introduction NO, n-masses, mn From NO to 0nbb-decay CP-phases, q13, sterile n Bosonic n and 2nbb-decay Conclusions 11/17/2018 Fedor Simkovic

massive neutrinos, SUSY... !!! Perspectives are opened !!! Standard Model Lepton Universality NEW PHYSICS massive neutrinos, SUSY... Lepton Family Number Violation Total Lepton Number Violation 11/17/2018 !!! Perspectives are opened !!! Fedor Simkovic

Neutrino oscillations  Massive neutrinos Reactor neutrinos Solar neutrinos 1968 Atmospheric neutrinos Accelerator neutrinos 1957 11/17/2018 Fedor Simkovic

-Maki-Nakagawa-Sakata Mixing of 3 light Neutrinos Pontecorvo -Maki-Nakagawa-Sakata matrix Flavor eigenstates Mass eigenstates mbb= S UeiUei mi ??? q13, CP- phases, hierarchy, absolute mass scale Mass matrix 11/17/2018 Fedor Simkovic

n-masses in flavor basis: Inverted hierarchy em et ee mm mt tt 11/17/2018 Fedor Simkovic Gozdz,Kaminski, F.Š, Faessler, Acta Phys. Pol. 37 (2006) 2203

n-masses in flavor basis: Normal hierarchy em et ee mt mm tt 11/17/2018 Fedor Simkovic Gozdz,Kaminski, F.Š, Faessler, Acta Phys. Pol. 37 (2006) 2203

n-oscillations  n magnetic moment n Majorana transitional magnetic moment n-oscillations  n magnetic moment n-e scattering g → nn 11/17/2018 Fedor Simkovic

Transitional magnetic moment of Majorana n R-parity violation SUSY, masses generated via lepton-slepton loops m0=m1/2=150 GeV, A0=100 GeV tan b=19 Inverted hierarchy Normal hierarchy 11/17/2018 Fedor Simkovic Gozdz,Kaminski, F.Š, Faessler, hep-ph/0606077, to be published in PRD

n-oscillations  0nbb-decay 11/17/2018 Fedor Simkovic

Double Beta Decay Observed for 10 isotopes: 48Ca, 76Ge, 82Se, 96Zr,100Mo. 116Cd. 128Te, 130Te, 150Nd, 238U, T1/2 ≈1018-1024 years SM forbidden ,not observed yet: T1/2 ( 76Ge)>1025 years 11/17/2018 Fedor Simkovic

Goals for 0nbb-experiments 1029-1030years Bilenky,Faessler, Gutsche, F.Š., PRD 72, 053015 (2005) Inverted hierarchy Normal hierarchy 11/17/2018 Fedor Simkovic 1027-1028years Goals for 0nbb-experiments 1029-1030years

Bilenky,Faessler, Gutsche, F.Š., PRD 72, 053015 (2005) q13 and the cancellation 11/17/2018 Fedor Simkovic Bilenky,Faessler, Gutsche, F.Š., PRD 72, 053015 (2005)

Perspectives of the 0nbb-search 11/17/2018 Fedor Simkovic

0nbb-decay NME 11/17/2018 Fedor Simkovic

NME-Nuclear structure approaches H Y = E Y We can not solve the full problem in the complete Systematical study of the 0nbb-decay NME Projected mean field (Vampir) ●Tomoda, Faessler, Schmid, Grummer, PLB 157, 4 (1985) Shell model: ●Haxton, Stephensson, Prog. Part. Nucl. Phys. 12, 409(1984) ●Caurier, Nowacki, Poves, Retamosa, PRL 77, 1954 (1996) QRPA, RQRPA: About 10 papers 1987→ 2006 Other approaches: Shell Model Monte Carlo (1996), Operator Expansion Method (1988-1994)... 11/17/2018 Fedor Simkovic

QRPA 2nbb-decay NME H = H0 + gph Hph + gpp Hpp 21 lev. 12 lev. Collapse of the QRPA 21 l.m.s. 12 l.m.c 11/17/2018 Fedor Simkovic

Recommended 0nbb-decay NME (April 2005) Neutrinoless Double Beta Decay Nuclear Matrix Elements Light Majorana Neutrino Exchange Mechanism Recommended 0nbb-decay NME (April 2005) V.Rodin, A. Faessler, F. Š., P. Vogel, NPA 766 (2006) 107 11/17/2018 Fedor Simkovic

Shell Model Define a valence space Derive an effective interaction H Y = E Y → Heff Yeff = E Yeff Build and diagonalize Hamiltonian matrix (1011) Transition operator < Yeff | Oeff | Yeff> Some phenomenological input needed energy of states, systematics of B(E2) and GT transitions (quenching f.) 48Ca → 48Ti 76Ge → 76Se 76Se42 in the valence 6 protons and 14 neutrons Small calculations 11/17/2018 Fedor Simkovic

Strasbourg group, Nowacki, IDEA meeting, Heidelberg, 2004 Comparison of M0n of Rodin et al. (RQRPA) and Nowacki et al. (SM, private comm., preliminary 2004, 2006) 0nbb-decay Nucleus RQRPA SM SM (2005) (2004) (2006) 76Ge 2.3-2.4 1.6 1.8 82Se 1.9-2.1 1.7 1.7 96Zr 0.3-0.4 0.4 100Mo 1.1-1.2 0.3 116Cd 1.2-1.4 1.9 130Te 1.3 2.0 (1.0) 1.7 136Xe 0.6-1.0 1.6 (0.6) 1.4 Except for 100Mo the agreement between these very different calculations is reasonably good. Note that the SM calculations include the reduction caused by the s.r.c. and induced currents (30%). SM results 2nbb-decay Isotope T1/2(th.)[y] T1/2(exp.)[y] 48Ca 3.7 1019 4.2 1019 76Ge 1.2 1021 1.4 1021 82Se 3.4 1019 9.0 1019 130Te 4. 1020 6.1 1020 136Xe 6. 1020 8.1 1020 Strasbourg group, Nowacki, IDEA meeting, Heidelberg, 2004 11/17/2018 Fedor Simkovic

Nuclear deformation Exp. I (nuclear reorientation method) Exp.II (based on measured E2 trans.) Theor. I (Rel. mean field theory) Theor. II (Microsc.-Macrosc. Model of Moeller and Nix) Till now, in the QRPA-like calculations of the 0nbb-decay NME spherical symmetry was assumed The effect of deformation on NME has to be considered 11/17/2018 Fedor Simkovic

New Suppression Mechanism of the DBD NME The suppression of the NME depends on relative deformation of initial and final nuclei F.Š., Pacearescu, Faessler. NPA 733 (2004) 321 Systematic study of the deformation effect on the 2nbb-decay NME within deformed QRPA Alvarez,Sarriguren, Moya,Pacearescu, Faessler, F.Š., Phys. Rev. C 70 (2004) 321 11/17/2018 Fedor Simkovic

Sterile neutrino in 0nbb-decay 11/17/2018 Fedor Simkovic

Sterile neutrino in 0nbb-decay 11/17/2018 Beneš, Faesler, F.Š., Kovalenko, PRD 71 (2005) 077901 Fedor Simkovic

Bosonic n in the 0nbb-decay 11/17/2018 Fedor Simkovic

Since n´s have spin one half they are believed to obey Fermi statistics Bosonic n introduced: Ignatiev, Kuzmin, Yad. Fiz 46 (1987) 786 Bosonic n in 2nbb-decay: Dolgov, Smirnov, PLB 621 (2005) 1 Motivations: Dark matter, BBN, supernova n For electrons and nucleons, a possible violation of statistics is strongly restricted by experiments. A consistent quantum field theory with of half-integer spin particles with any other statistics than the Fermi one is missing 11/17/2018 Fedor Simkovic

2nbb-decay: fermionic (f) or bosonic (b) n Sign difference!!! Lepton energies!!! 11/17/2018 Fedor Simkovic

Barabash, Dolgov, Dvornický, F.Š., Smirnov, in preparation 2nbb-decay of 100Mo 0+g.s.→ 0+g.s Barabash, Dolgov, Dvornický, F.Š., Smirnov, in preparation bosonic fermionic 11/17/2018 Fedor Simkovic

Mixed statistics Definition: Commutators: Amplitude: Decay rate: 11/17/2018 Fedor Simkovic

Large admixture of bosonic n excluded: b2 < 0.75 Barabash, Dolgov, Dvornický, F.Š., Smirnov, in preparation SSD free of log ft values Large admixture of bosonic n excluded: b2 < 0.75 11/17/2018 Fedor Simkovic

Sensitive to a small admixture of bosonic n Barabash, Dolgov, Dvornický, F.Š., Smirnov, in preparation SSD free of log ft values HSD nuclei even more sensitive to admixture of bosonic n but calculation of M.E. needed 11/17/2018 Fedor Simkovic

Outlook (NME) What is the dominant mechanism of the 0nbb-decay? There will be a progress Moore’s law of 0nbb-decay Elliott, Vogel, Ann.Rev.Nucl.Part.Sci. 52 (2002)115 Shell model: increased computer power, larger m.s., better effective interactios, new groups (T. Otsuka – Tokyo U.) MCSM: unsolved problems? H. Nakada (NNR05), Alhassid, Bertsch, Liu, Fang Projected mena field: New calculations are planed, Petrovici, Schmid QRPA: further progress expected → effects of deformation, overlap factor What is the dominant mechanism of the 0nbb-decay? Inverted hierarchy NME + PPP There is still some time 11/17/2018 Fedor Simkovic