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b +. n e. The Weak Interaction in Low Energy Nuclear Physics. ARIS-2014 Tokio, June 1-6, 2014. Nathal Severijns KU Leuven, Belgium. e +. nucleus. q. n e. Overview. recent / ongoing achievements - APV and EDM - V ud and unitarity / Ft-values - exotic weak currents - PowerPoint PPT Presentation
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The Weak Interaction
in
Low Energy Nuclear Physics
Nathal Severijns
KU Leuven, Belgium
ARIS-2014Tokio, June 1-6, 2014
+
e
e+
e
nucleus
- 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
- conclusion and outlook
Overview
1. Atomic Parity Violation & Electric Dipole Moments
Atomic Parity Violation
Electric Dipole Moments
225Ra @ ANL and KVI223Rn @ TRIUMF129Xe @ 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
probing sin2W at atomic energies (test Standard Model)
206Fr @ TRIUMF, LNL223Ra @ KVI
enhancement factors of ~15 and ~50 compared to 133Cs case (Wiemann et al.)
matter/anti-matter difference in the Universe
2. Vud quark mixing matrix element & CKM unitarity
Towner & Hardy, Rep. Prog Phys. 73 (2010) 046301
= 3071.81(83) s
fromexperiment
nucleus dependent corrections nucleus independent
2 2 2 0.99991(51)ud us ubV V V
|Vus| = 0.22564(53)
|Vud| = 0.97425(22)
Hardy & Towner, PR C 79 (2009) 055502
Dowdall et al., Phys. Rev. D 88, 074504 (2013)
prospects - 1
1. superallowed Fermi transitions
- new data for 0+ 0+ pure Fermi transitions
- testing isospin corrections C
- nucleus-independent radiative correction R
2. corrected Ft values of T = 1/2 mirror transitions and neutron decay could contribute as well
A GT
V F
C M
C M 2 0 0
2 21 2 =
(1 )A
V
mirrorV
F ud R
f
f
KFt Ft
G V
O. Naviliat-Cuncic & N.S. , PRL 102 (2009) 142302N.S. , I.S. Towner et al.,
Phys. Rev. C 78(2008) 055501
prospects - 2
2a. Neutron decay
-no nuclear structure related corrections
-issues of lifetime and asymmetry parameter first have to be resolved
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
(if A/A = 0.5% Vud = 0.0004)
- requires measurements of QEC, t1/2 and BR leading to Ft values for mirror transitions
N.S. & O. Naviliat-Cuncic, Physica Scripta T152 (2013) 014018
3. Exotic weak currents (scalar, tensor, V+A)
e
e
p qa
E E
= 1
e
e
mb
E
aa
2with 1 ( )Z
2A
2'T
2T
2V
2's
2S
|C|
|C| |C| 1
3
1
|C|
|C| |C| 1
GT
F
a
a
A
'TT
V
'SS
C
C C e
C
C C e
Rb
Rb
GT
F
Fierz term
1. correlation
exp.
!!! for pure transitions weak interaction results are independent of nuclear matrix elements !!!
search for scalar couplings
scalar - TRINAT MOT trap at TRIUMF-ISAC – 38mK
38m 38 +K Ar + e + ν
superallowed 0+ 0+ pure Fermi transition
(t1/2 = 0.95 s)
A. Gorelov, J. Behr et al.,Phys. Rev. Lett. 94 (2005) 142501
= 0 = .9 1
981(30)(35)e
e
aa
mb
E
2 ' 2
2
(90% C.L.)
| | | | 0.097
|
|SS
V
C C
C
TOF
ongoing experiments in search for scalar weak currents:
- LPCTrap-GANIL (Paul): 19Ne, 35Ar PS1-A065 – Delahaye
- WITCH-ISOLDE (Penning): 35Ar
- Jerusalem (MOT): 19Ne
- TamuTrap , Texas (Paul): 32Ar (T=2, βp)
35Ara/a ~ 0.3%(analysis in progress)
scalar: a = -1
vector: a = +1
35Ar
LPCTrap - GANIL
WITCH
poster D. Zakoucky PS1-A061
preliminary
preliminary
Limits on scalar currents
Towner & Hardy, Rep. Prog Phys. 73 (2010) 046301
38mK: Gorelov, Behr et al., PRL 94 (2005) 142501
= 3071.81(83) s
Tensor - LPCTrap @ GANIL - 6He / 35Ar
2006 (6He): aβν = −0.3335(73)stat(75)syst
X. Fléchard et al., J. Phys. G 38 (2011) 055101
Li3+
Li2+
a/a ~ 0.5 % (stat) (analysis in progress)
20106He
charge-state distribution and comparison to atomic theory:
C. Couratin et al., PRL 108 (2012) 243201
1083 nm
T
Tensor - 6He MOT Trap setup @ Univ. Washington, SeattleP. Mueller, A. Garcia, et al.
• RF discharge -> metastable He*• Laser cooling @ 1083 nm • Timeline: - 6He produced and trapped - first data run in August 2013 --> 1 % measurement
- 0.1 % measurement by 2015
6He Trap/Detector Chamber
Trap-to-trap transfer: > 60% efficiency, ~15 ms
6He Trapping Rates @ CENPA: @ source: 5x109 s-1 ; capt. efficiency = 2x10-7; @ trap: 1000 s-1
A. Knecht et al., NIM A 660 (2011) 43, Phys .Rev. C 86 (2012) 035506 & arXiv:1208.6433v2 [nucl-ex]
PS2-B005 – Mueller
04/20/23 13 N. Severijns, CGS14 conference - Aug. 28 - Sept. 02, 2011
O. Aviv et al., J. Phys.: Conf. Ser. 337, 012020 (2012)
8 2eLi e
aβν = −0.3307 (60)stat (67)sys
G.Li, G.Savard et al., PRL 110 (2013) 082502
Tensor - -- Correlation in Paul trapped 8Li IonsG. Savard et al. (ANL, Mc. Gill, LLNL, Univ. Chicago, … )
data with ~20 times more statistics + lower systematics to be published
1% or betterPoster PS2-B004 – Perez Galvan
F. Wauters et al., Phys. Rev. C 80 (2009) 062501(R)
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 80 (2009) 062501(R)
F. Wauters et al., Phys. Rev. C 82 (2010) 055502
regionanalysed
G. Soti et al., submitted to PR C
Tensor - β asymmetry – Leuven / ISOLDE / Prague
F. Wauters et al., NIM A 609 (2009) 156
Constraints on tensor type weak couplings
A(60Co)
A(67Cu)
a(6He)
--(8Li)
a(6He)C. Johnston et al.,
PR 132 (1963) 1149 A(60Co)F. Wauters, N.S. et al.,
PR C 82 (2010) 055502
--(8Li)G.Li, G.Savard et al.,
PRL 110 (2013) 082502
A(67Cu)G. Soti, N.S. et al., (2013) submitted
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 !!
'1 ( , ) 1 k F Fierz WMd G F Z E b k E b
E
miniBETA spectrometer (Leuven / Krakow)
multi-wire drift chamber scintillator(later DSSDD)
poster P. Finlay PS2-CO23
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
access to A and other correlations involving nuclear spin
New vistas and prospects in the LHC era - 2
- perform more measurements with polarized nuclei
O. Naviliat-Cuncic and M. Gonzalez-AlonsoAnnalen der Physik (2013) in print.
V. Cirigliano, et al., J. High. Energ. Phys. 1302 (2013) 046
Precision measurements in nuclear/neutron decay in the LHC era
90 % CL90 % CL
nuclear and neutron decay, pion decay limits on scalar/tensor couplingsobtained 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)
- 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
- 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 planned / in preparation
Conclusions and Outlook
EDM - APV: Par. 1C – SatoPS1-A064 – OhtomoPS1-A066 – OhtomoPS1-A067 – MuellerPS2-B001 – KawamuraPS2-B002 – TeruyaPS2-B003 – InouePS2-C020 – Harada (APV)
ββ-decay: Par. 1C – HinoharaPS1-A064 – RinglePS2-B006 – Yoshinaga
Superallowed Fermi: Par. 1C – LaffoleyPar. 1C – ParkPS1-A062 – BlankPS1-A063 – Nishimura
β-decay correlations: PS1-A061 – Zakouckyand β-spectrum shape PS1-A065 – Delahaye
PS2-B004 – Perez GalvanPS2-B005 – MuellerPS2-C023 – Finlay (spectrum shape)
Contributed talks and Posters
Backup slides
Most precise correlation measurements
Particle traps: ideal sources
- sample is isotopically pure
- localized in a small volume
- atoms decay at rest
- detection of recoil ion
- negligible source scattering
- potential for polarized samplePenning
MOTPaul
Ion/atom traps for - correlation measurements
Overview of - correlation projects
N.S. & O. Naviliat-Cuncic, Physica Scripta T152 (2013) 014018
a = −0.3307(60)(67)
MOT trap for radioactive Ne isotopes G. Ron et al. (Hebrew Univ., Weizmann Inst. and SOREQ – Israel)
Zeeman slower
double-trap MOT concept (similar to TRINAT)
17,18,19,23,24Ne
- p/d accelerator (5mA/up to 40MeV)
- neutron generator
G. Ron, priv. comm.
04/20/23
Goal : determine correlation for 35Ar with (a/a)stat 0.5 %
measure energy spectrum of recoiling ions with a retardation spectrometer
WITCH @ ISOLDE - 35Ar - scalar(KU Leuven, Univ. Munster, ISOLDE, NPI Rez-Prague, LPC-Caen)
scalar: a = -1
vector: a = +1
poster by Paul Finlay
M. Beck et al., Eur. Phys. J. A47 (2011) 45
M. Tandecki et al., NIM A629 (2011) 396
S. Van Gorp et al., NIM A638 (2011) 192
preliminary