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Double-beta decay and BSM physics: shell model nuclear matrix elements for competing mechanisms. Mihai Horoi Department of Physics, Central Michigan University, Mount Pleasant, Michigan 48859, USA
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Double-beta decay and BSM physics: shell model nuclear matrix elements for competing mechanisms Mihai Horoi Department of Physics, Central Michigan University, Mount Pleasant, Michigan 48859, USA Support from NSF grant PHY-1404442 and DOE/SciDACgrants DE-SC0008529/SC0008641 is acknowledged M. Horoi CMU
Overview • Neutrino physics within and beyond the Standard Model (BSM) • DBD mechanisms: light Majorana neutrino exchange, right-handed currents, heavy neutrinos, SUSY R-parity violation,… • 48Ca: 2v and 0v shell-model matrix elements • Beyond closure approximation • 76Ge, 82Se, 130Te, and 136Xe results M. Horoi CMU
Classical Double Beta Decay Problem A.S. Barabash, PRC 81 (2010) 2-neutrino double beta decay neutrinoless double beta decay Adapted from Avignone, Elliot, Engel, Rev. Mod. Phys. 80, 481 (2008) -> RMP08 M. Horoi CMU
Neutrino Masses • Tritium decay: • Cosmology: CMB power spectrum, BAO, etc, Two neutrino mass hierarchies M. Horoi CMU
Neutrino bb effective mass 76Ge Klapdor claim 2006 Cosmology constraint M. Horoi CMU
? The Minimal Standard Model M. Horoi CMU
Too Small Yukawa Couplings? arXiv:1406.5503 Standard Modelfermion masses M. Horoi CMU
The origin of Majorana neutrino masses Type I see-saw • SU2eimiterm dominates in most cases • TeVcollider Majorana tests not relevant arXiv:0710.4947v3 M. Horoi CMU
The origin of Majorana neutrino masses See-saw mechanisms Left-Right Symmetric model WR search at CMS arXiv:1407.3683 arXiv:0710.4947v3 M. Horoi CMU
Majorananeutrino masses M. Horoi CMU
Low-energy contributions to 0vbbdecay Low-energy effective Hamiltonian M. Horoi CMU
Contributions to 0vbbdecay: no neutrinos See-saw type III GUT/SUSY R-parity violation Squark exchange Hadronization /w R-parity v. Gluino exchange M. Horoi CMU
The Black Box Theorem J. Schechter and J.W.F Valle, PRD 25, 2951 (1982) E. Takasugi, PLB 149, 372 (1984) J.F. Nieves, PLB 145, 375 (1984) M. Hirsch, S. Kovalenko, I. Schmidt, PLB 646, 106 (2006) (i) Neutrinos are Majorana fermions. (ii) Lepton number conservation is violated by 2 units 0nbb observed at some level Regardless of the dominant 0nbb mechanism! M. Horoi CMU
DBD signals from different mechanisms arXiv:1005.1241 2b0n rhc(h) M. Horoi CMU
PRD 83, 113003 (2011) The 0vDBD half-life M. Horoi CMU
Two Non-Interfering Mechanisms Assume T1/2(76Ge)=22.3x1024y M. Horoi CMU
Is there a more general description? Long-range terms: (a) - (c ) Short-range terms: (d) M. Horoi CMU
Summary of 0vDBD mechanisms • The mass mechanism (a.k.a. light-neutrino exchange) is likely, and the simplest BSM scenario. • Low mass sterile neutrino would complicate analysis • Right-handed heavy-neutrino exchange is possible, and requires knowledge of half-lives for more isotopes. • h- and l- mechanisms are possible, but could be ruled in/out by energy and angular distributions. • Left-right symmetric model may be also (un)validated at LHC/colliders. • SUSY/R-parity, KK, GUT, etc, scenarios need to be checked, but validated by other means. M. Horoi CMU
2v Double Beta Decay (DBD) of 48Ca The choice of valence space is important! Ikeda satisfied in pf ! Horoi, Stoica, Brown, PRC 75, 034303 (2007) M. Horoi CMU
Double Beta Decay NME for 48Ca M. Horoi, PRC 87, 014320 (2013) M. Horoi CMU
Closure Approximation and Beyond in Shell Model Challenge: there are about 100,000 Jk states in the sum for 48Ca Much more intermediate states for heavier nuclei, such as 76Ge!!! No-closure may need states out of the model space (not considered). Minimal model spaces 82Se : 10M states 130Te : 22M states 76Ge : 150M states M. Horoi CMU
82Se: PRC 89, 054304 (2014) M. Horoi CMU
New Approach to calculate NME: New Tests of Nuclear Structure Brown, Horoi, Senkov arXiv:1409.7364, M. Horoi CMU
136Xe bb Experimental Results EXO-200 arXiv:1402.6956, Nature 510, 229 M. Horoi CMU
136Xe 2nbb Results New effective interaction, 0g7/2 1d5/2 1d3/2 2s5/2 0h11/2 model space 0h9/2 0h9/2 0h9/2 0h9/2 0h11/2 2s5/2 1d3/2 1d5/2 0g7/2 0h11/2 2s5/2 1d3/2 1d5/2 0g7/2 0h11/2 2s5/2 1d3/2 1d5/2 0g7/2 0g9/2 0g7/21d5/2 1d3/2 2s5/2 0h11/2 0h9/2 0h11/2 2s5/2 1d3/2 1d5/2 0g7/2 0g9/2 0g9/2 0g9/2 0g9/2 np - nh M. Horoi CMU
S. Vigdor talk at LRP Town Meeting, Chicago, Sep 28-29, 2014 M. Horoi CMU
IBA-2 J. Barea, J. Kotila, and F. Iachello, Phys. Rev. C 87, 014315 (2013). QRPA-En M. T. Mustonen and J. Engel, Phys. Rev. C 87, 064302 (2013). QRPA-Jy J. Suhonen, O. Civitarese, Phys. NPA 847 207–232 (2010). QRPA-TuA. Faessler, M. Gonzalez, S. Kovalenko, and F. Simkovic, arXiv:1408.6077 ISM-Men J. Menéndez, A. Poves, E. Caurier, F. Nowacki, NPA 818 139–151 (2009).SM M. Horoi et. al. PRC 88, 064312 (2013), PRC 89, 045502 (2014),PRC 90, PRC 89, 054304 (2014), in preparation, PRL 110, 222502 (2013). M. Horoi CMU
IBA-2 J. Barea, J. Kotila, and F. Iachello, Phys. Rev. C 87, 014315 (2013). QRPA-TuA. Faessler, M. Gonzalez, S. Kovalenko, and F. Simkovic, arXiv:1408.6077 SM M. Horoi et. al. PRC 88, 064312 (2013),PRC 90, PRC 89, 054304 (2014), in preparation, PRL 110, 222502 (2013). M. Horoi CMU
Take-Away Points Observation of 0nbb will signal New Physics Beyond the Standard Model. Black box theorem (all flavors + oscillations) (i) Neutrinos are Majorana fermions. (ii) Lepton number conservation is violated by 2 units 0nbb observed at some level Regardless of the dominant 0nbb mechanism! M. Horoi CMU
Take-Away Points The analysis and guidance of the experimental efforts need accurate Nuclear Matrix Elements. M. Horoi CMU
Take-Away Points Extracting information about Majorana CP-violation phases may require the mass hierarchy from LBNE, cosmology, etc, but also accurateNuclear Matrix Elements. M. Horoi CMU
Take-Away Points Alternative mechanisms to 0nbb need to be carefully tested: many isotopes, energy and angular correlations. These analyses also require accurateNuclear Matrix Elements. SuperNEMO; 82Se M. Horoi CMU
Take-Away Points Accurate shell model NME for different decay mechanisms were recently calculated. The method provides optimal closure energies for the mass mechanism. Decomposition of the matrix elements can be used for selective quenching of classes of states, and for testing nuclear structure. 76Ge M. Horoi CMU
Experimental info needed M. Horoi CMU
Collaborators: • Alex Brown, NSCL@MSU • Roman Senkov, CMU and CUNY • Andrei Neacsu, CMU • Jonathan Engel, UNC • Jason Holt, TRIUMF M. Horoi CMU
Summary and Outlook • Observation of neutrinoless double beta decay would signal physics beyond the Standard Model: massive Majorana neutrinos, right-handed currents, SUSY LNV, etc • 48Ca and 136Xe cases suggest that 2 double-beta decay can be described reasonably within the shell model with standard quenching, provided that all spin-orbit partners are included. • Higher order effects for 0 NME included: range 1.0 – 1.4 • Reliable 0bb nuclear matrix elements could be used to identify the dominant mechanism if energy/angular correlations and data for several isotopes become available. • The effects of the quenching and the missing spin-orbit partners are important (see the 136Xe case), and they need to be further investigated for 76Ge, 82Se and 130Te. M. Horoi CMU
Effective Field Theory for BSM V. Ciriglianotalk at LPR Town Meeting, Chicago, Sep 28-29, 2014 M. Horoi CMU
Effective Field Theory for BSM M. Hirsch talk at NEUTRINO 2014 M. Horoi CMU
Comparisons of M0n 0nbb Results From T. Rodriguez, G. Martinez-Pinedo, Phys. Rev. Lett. 105, 252503 (2010) (MS) Present Shell Model results: Phys. Rev. Lett. 110, 222502 (2013) PRC 89, 045502 & 88, 064312 (2013) PRC 89, 054304 (2014), submitted M. Horoi CMU
Shell Model GT Quenching empty valence frozen core core polarization: Phys.Rep. 261, 125 (1995) J. Menendez, D. Gazit and A. Schwenk, arXiV:1103.3622, PRL 107 M. Horoi CMU
? The Minimal Standard Model M. Horoi CMU
The effect of larger model spaces for 48Ca arXiv:1308.3815, PRC 89, 045502 (2014) SDPFU: PRC 79, 014310 (2009) PRC 87, 064315 (2013) SDPFMUP: PRC 86, 051301(R) (2012) M. Horoi CMU
Other Shell Model Results 0g7/2 1d5/2 1d3/2 2s5/2 0h11/2 valence space M. Horoi CMU
S. Vigdor talk at LPR Town Meeting, Chicago, Sep 28-29, 2014 M. Horoi CMU
The Black Box Theorem J. Schechter and J.W.F Valle, PRD 25, 2951 (1982) E. Takasugi, PLB 149, 372 (1984) J.F. Nieves, PLB 145, 375 (1984) M. Hirsch, S. Kovalenko, I. Schmidt, PLB 646, 106 (2006) However: M. Duerr et al, JHEP 06 (2011) 91 (i) Neutrinos are Majorana fermions. (ii) Lepton number conservation is violated by 2 units 0nbb observed at some level Regardless of the dominant 0nbb mechanism! M. Horoi CMU
Neutrino Oscillations IH NH M. Horoi CMU
Low-energy contributions to 0vbbdecay Low-energy effective Hamiltonian M. Horoi CMU
PRD 86, 055006 (2012) Some mechanisms tested at LHC Left-right symmetric model arXiv:1307.4849 M. Horoi CMU
Broken D-parity left-right symmetric model: arXiv:1409.2820 Some mechanisms tested at LHC Recent CMS results a 2.8s effect arXiv:1407.3683 M. Horoi CMU