Tests of fundamental weak interactions and their symmetries using exotic nuclei EuNPConference Groningen, Aug 30 – Sep 04, 2015 b+ ne Nathal Severijns KU Leuven, Belgium

Overview recent / ongoing achievements - APV and EDM e+ ne nucleus q recent / ongoing achievements - APV and EDM - Vud and unitarity / Ft-values - exotic weak currents (scalar, tensor, V+A) (selected experiments showing diversity in techniques used) - new vistas and prospects for this field in the LHC era N.S., O. Naviliat-Cuncic & M. Beck, RMP 78 (2006) 991 H. Abele, Prog Part Nucl Phys 60 (2008) 1 D. Dubbers and M.G. Schmidt, RMP 83 (2011) 1111 N.S. & O. Naviliat-Cuncic, Phys Scr T152 (2013) 014018 F. Wauters et al., PR C 89 (2014) 025501 S Baeßler et al., J. Phys. G: Nucl. Part. Phys. 41 (2014) 114003 K. Vos et al., RMP (2015) to be published see also the talk of Keri Vos

1. Atomic Parity Violation & Electric Dipole Moments probing sin2W at atomic energies (test Standard Model) 206Fr @ TRIUMF, LNL 223Ra @ KVI enhancement factors of ~15 and ~50 compared to 133Cs case (Wiemann et al.) Electric Dipole Moments matter/anti-matter difference in the Universe 225Ra @ ANL and KVI 223Rn @ TRIUMF 129Xe @ Tokyo and TUM sensitivity to EDM enhanced by (by several 100 to few 1000 times): - near degeneracy of atomic levels - octupole deformation of nuclear charge distribution

topics that will not be discussed now - neutrino-mass determination in EC-decay of 163Ho talk F. Schneider - test of Lorentz violation in -decay of 20Na talk A. Sytema - double beta decay talk T. Rodríguez - theory talk R. Brugnera - GERDA experiment talk C. Pagliarone - CUORE experiment - parity non-conservation posters 18 & 53

2. Vud quark mixing matrix element & CKM unitarity from experiment nucleus dependent corrections nucleus independent |Vud| = 0.97425(22) Hardy & Towner, PR C 79 (2009) 055502 |Vud| = 0.97417(21) Hardy & Towner, PR C 91 (2015) 025501 = 3072.27(72) s |Vus| = 0.22564(53)  0.2253(8) Hardy & Towner , Phys. Rev. C 91 (2015) 025501

O. Naviliat-Cuncic & N.S. , PRL 102 (2009) 142302 prospects - 1 superallowed Fermi transitions - new data for 0+  0+ pure Fermi transitions - testing isospin corrections C - nucleus-independent radiative correction R talk L. Xayavang T = 1/2 mirror  transitions and neutron decay could contribute as well N.S. , I.S. Towner et al., Phys. Rev. C 78(2008) 055501 |Vud| = 0.9719(17) O. Naviliat-Cuncic & N.S. , PRL 102 (2009) 142302

prospects - 2 talk C. Magron 2a. Neutron decay no nuclear structure related corrections issues of lifetime and asymmetry parameter first have to be resolved (PERKEO-PERC, new lifetime measurements) 2b. T = 1/2 mirror  transitions could contribute as well additional tests for isospin corrections C provide additional value for Vud (set of consistent data needed) good cases: e.g. 19Ne: β-corr. measurement performed with LPCTrap 35Ar : β-corr. measurement performed with LPCTrap; β-asym. measurement in preparation at ISOLDE (if A/A = 0.5%  Vud = 0.0004) - requires measurements of QEC, t1/2 and BR leading to Ft values for mirror transitions talk C. Magron N.S. & O. Naviliat-Cuncic, Physica Scripta T152 (2013) 014018

3. Exotic weak currents (scalar, tensor, V+A) 1.  correlation exp. Fierz term !!! for pure transitions weak interaction results are independent of nuclear matrix elements !!!

scalar - TRINAT MOT trap at TRIUMF-ISAC – 38mK search for scalar couplings superallowed 0+  0+ pure Fermi transition (t1/2 = 0.95 s) A. Gorelov, J. Behr et al., Phys. Rev. Lett. 94 (2005) 142501 TOF

ongoing experiments in search for scalar weak currents: - LPCTrap-GANIL (Paul): 19Ne, 35Ar - Jerusalem (MOT): 19Ne - TamuTrap , Texas A&M (Paul): 32Ar, … (T=2, βp) talk B. Chayon Da/a ~ 0.3% (analysis in progress) 35Cl charge state distribution from the  decay of 35Ar (LPCTrap - GANIL) preliminary

Limits on scalar currents Hardy & Towner , Phys. Rev. C 91 (2015) 025501 38mK: Gorelov, Behr et al., PRL 94 (2005) 142501

Tensor - LPCTrap @ GANIL - 6He 2006 (6He): aβν = −0.3335(73)stat(75)syst [ X. Fléchard et al., J. Phys. G 38 (2011) 055101 ] Tensor - 6He MOT Trap setup @ Univ. Washington, Seattle P. Mueller, A. Garcia, et al. - first data run in August 2013 --> 1 % measurement - 0.1 % measurement by 2015 A. Knecht et al., NIM A 660 (2011) 43, Phys .Rev. C 86 (2012) 035506 & arXiv:1208.6433v2 [nucl-ex]

Tensor - -- correlation with Paul-trapped 8Li Ions Tensor - 6He EIB Trap (Weizmann Inst., Univ. Jerusalem, … ) (M. Hass, G. Ron et al.) Tensor - -- correlation with Paul-trapped 8Li Ions aβν = −0.3307 (60)stat (67)sys G.Li, G.Savard et al., PRL 110 (2013) 082502 data with ~20 times more statistics + lower systematics to be published   1% or better

Tensor - β asymmetry – Leuven / ISOLDE / Prague F. Wauters et al., NIM A 609 (2009) 156 region analysed Aexp (60Co) = - 1.014 (12)stat (16)syst Aexp (114In) = - 0.990 (10)stat (10)syst Aexp (67Cu) = 0.587(8)stat (12)syst F. Wauters et al., Phys. Rev. C 82 (2010) 055502 F. Wauters et al., Phys. Rev. C 80 (2009) 062501(R) F. Wauters et al., Phys. Rev. C 80 (2009) 062501(R) G. Soti et al., submitted to PR C 90 (2014) 035502

Constraints on tensor type weak couplings a(6He) C. Johnston et al., PR 132 (1963) 1149 --(8Li) G.Li, G.Savard et al., PRL 110 (2013) 082502 A(60Co) F. Wauters, N.S. et al., PR C 82 (2010) 055502 A(67Cu) G. Soti, N.S. et al., (2013) submitted --(8Li) A(60Co) A(67Cu) a(6He)

New vistas and prospects in the LHC era - 1 new generation of trap-based experiments  towards 0.1% precision level precise -spectrum shape measurements (Leuven-Krakow, MSU-NSCL, LPC Caen, … ) bFierz : scalar / tensor weak currents bWM : weak magnetism (Standard Model term) - induced by strong interaction because decaying quark is not free but bound in a nucleon; - is to be known better when reaching sub-percent precisions Note the different energy dependence of both effects !!

microcalorimeter measurements (CEA-Saclay) recent work improving beta spectral shape at very low energies X. Mougeot et al., PR A 86 (2012) 042506, PR A 90 (2014) 012501

miniBETA spectrometer (Leuven / Krakow) multi-wire drift chamber scintillator (later DSSDD)

double-Si spectrometer (Leuven / Krakow) two Si p-i-n detectors at distance of 7 mm 45Ca

Beta energy spectrum shape in 6He decay - NSCL/MSU (O. Naviliat-Cuncic et al.) Effect of weak magnetism (Monte-Carlo simulation) Long term goal: Measure the Fierz interference term (b) in 6He decay to search for tensor-type contributions to the weak interactions. Current goal: measure the weak magnetism (WM) form factor in 6He decay for a tests of the strong form of CVC. The WM is the largest "hadronic SM background" in a measurement of b. 2% Single detector 2×107 events Principle: use a fragmented separated beam to eliminate distortions in beta spectrum due to back-scattering, out-scattering or dead-layers. radioactive 6He source [Run145-segs:0,1,2-Tw:550-850] [Run182-segs:0,1-Ew:500-2500] Experiment at NSCL range of b particles 6He decay 6He 46 MeV/A Pile-up fraction <1.8x10-3 Collected statistics enables extracting the WM form factor at ~10% relative error. Electron kinetic energy (chan)

New vistas and prospects in the LHC era - 2 - perform more measurements with polarized nuclei access to A and other correlations involving nuclear spin Beta and recoil asymmetries w.r.t. nuclear spin : MOT trap : optical pumping in the trap, in magnetic holding field TRIUMF: 80Rb, 37K Jerusalem-Tel Aviv-Rehovot: 19Ne ULiège-KU Leuven: 35Ar collinear laser optical pumping NSCL-BECOLA, ISOLDE-COLLAPS: 21Na, 23Mg, 35Ar, 37K

Precision measurements in nuclear/neutron  decay in the LHC era nuclear and neutron decay, pion decay limits on scalar/tensor couplings obtained by CMS collaboration in pp  e + MET + X channel - S. Chatrchyan et al. (CMS Collab.) J. High. Energ. Phys. 1208 (2012) 023; - CERN Rep. nr. CMS-PAS-EXO-12-060 (2013) O. Naviliat-Cuncic and M. Gonzalez-Alonso Annalen der Physik 525 (2013) 600. V. Cirigliano, et al., J. High. Energ. Phys. 1302 (2013) 046

Conclusions and Outlook - pure Fermi transition Ft-values, and possibly neutron decay parameters and correlation measurements in mirror  transitions  contribute to further improving precision of Vud mixing matrix element; - - correlation and  asymmetry measurements + Ft-values  improved limits on scalar and tensor type weak currents; - additional observable: beta-spectrum shape  scalar/tensor currents and weak magnetism polarized atoms/ions in trap would extend observables accessible with traps - searches for new physics (bosons) at low energies remain competitive with direct searches at LHC when concentrating on Fierz term and Vud - many experiments ongoing or in preparation / planned