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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
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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
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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
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Neutrino oscillations Massive neutrinos
Reactor neutrinos Solar neutrinos 1968 Atmospheric neutrinos Accelerator neutrinos 1957 11/17/2018 Fedor Simkovic
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-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
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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
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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
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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
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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/ , to be published in PRD
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n-oscillations 0nbb-decay
11/17/2018 Fedor Simkovic
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Double Beta Decay Observed for 10 isotopes: 48Ca, 76Ge, 82Se, 96Zr,100Mo. 116Cd. 128Te, 130Te, 150Nd, 238U, T1/2 ≈ years SM forbidden ,not observed yet: T1/2 ( 76Ge)>1025 years 11/17/2018 Fedor Simkovic
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Goals for 0nbb-experiments 1029-1030years
Bilenky,Faessler, Gutsche, F.Š., PRD 72, (2005) Inverted hierarchy Normal hierarchy 11/17/2018 Fedor Simkovic years Goals for 0nbb-experiments years
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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, (2005)
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Perspectives of the 0nbb-search
11/17/2018 Fedor Simkovic
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0nbb-decay NME 11/17/2018 Fedor Simkovic
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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 ( )... 11/17/2018 Fedor Simkovic
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QRPA 2nbb-decay NME H = H0 + gph Hph + gpp Hpp 21 lev. 12 lev.
Collapse of the QRPA 21 l.m.s l.m.c 11/17/2018 Fedor Simkovic
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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
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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
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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 82Se 96Zr 100Mo 116Cd 130Te (1.0) 136Xe (0.6) 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 76Ge 82Se 130Te 136Xe Strasbourg group, Nowacki, IDEA meeting, Heidelberg, 2004 11/17/2018 Fedor Simkovic
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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
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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
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Sterile neutrino in 0nbb-decay
11/17/2018 Fedor Simkovic
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Sterile neutrino in 0nbb-decay
11/17/2018 Beneš, Faesler, F.Š., Kovalenko, PRD 71 (2005) Fedor Simkovic
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Bosonic n in the 0nbb-decay
11/17/2018 Fedor Simkovic
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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
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2nbb-decay: fermionic (f) or bosonic (b) n
Sign difference!!! Lepton energies!!! 11/17/2018 Fedor Simkovic
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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
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Mixed statistics Definition: Commutators: Amplitude: Decay rate:
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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
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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
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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
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