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ABSTRACT: We explore the possibility that the weak interaction violates Lorentz, and in
particular rotational, invariance in neutron and allowed nuclear beta decay. A
broad class of Lorentz-violating effects is considered, in which the standard
propagator of the W-boson acquires an additional Lorentz-violating tensor. The
general decay rate for allowed beta decay that incorporates such a modified
propagator is derived. The resulting Lorentz-violating signals are discussed
for the different types of beta-decay transitions, Fermi, Gamow-Teller, and
mixed. We study the implications of our formalism for dedicated beta-decay
experiments. We give a short overview of the few relevant experiments that have
been performed or are ongoing.
02/2013;
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G. S. Giri,
O. O. Versolato,
J. E. van den Berg,
O. Böll,
U. Dammalapati,
D. J. van der Hoek,
K. Jungmann,
W. L. Kruithof,
S. Müller,
M. Nuñez Portela,
C. J. G. Onderwater,
B. Santra,
R. G. E. Timmermans,
L. W. Wansbeek,
L. Willmann, H.W. Wilschut
[show abstract]
[hide abstract]
ABSTRACT: Laser spectroscopy of short-lived radium isotopes in a linear Paul trap has been performed. The isotope shifts of the 6d 2 D3/2 –7 p 2 P1/2 transition in 209−214Ra+, which are sensitive to the short-range part of the atomic wave functions, were measured. The results are essential experimental input for improving the precision of atomic structure calculations. This is indispensable for parity violation in Ra+ aiming at the determination of the weak mixing angle.
Physical Review A. 08/2011; 84(2).
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G. S. Giri,
O. O. Versolato,
J. E. van den Berg,
O. Böll,
U. Dammalapati,
D. J. van der Hoek,
K. Jungmann,
W. L. Kruithof,
S. Müller,
M. Nuñez Portela,
C. J. G. Onderwater,
B. Santra,
R. G. E. Timmermans,
L. W. Wansbeek,
L. Willmann, H. W. Wilschut
[show abstract]
[hide abstract]
ABSTRACT: Laser spectroscopy of short-lived radium isotopes in a linear Paul trap has
been performed. The isotope shifts of the $6d\,^2$D$_{3/2}\,$ -
$7p\,^2$P$_{1/2}\,$ transition in $^{209-214}$Ra$^+$ were measured, which are
sensitive to the short range part of the atomic wavefunctions. The results are
essential experimental input for improving the precision of atomic structure
calculation. This is indispensable for parity violation in Ra$^+$ aiming at the
determination of the weak mixing angle.
08/2011;
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[show abstract]
[hide abstract]
ABSTRACT: We explore the potential of the electric quadrupole transitions 7s 2S1/2-6d 2D3/2, 6d 2D5/2 in radium isotopes as single-ion optical frequency standards. The frequency shifts of the clock transitions due to external fields and the corresponding uncertainties are calculated. Several competitive ARa+ candidates, with A= 223–229, are identified. In particular, we show that the transition 7s 2S1/2 (F=2,mF=0)-6d 2D3/2 (F=0,mF=0) at 828 nm in 223Ra+, with no linear Zeeman and electric quadrupole shifts, stands out as a relatively simple case, which could be exploited as a compact, robust, and low-cost atomic clock operating at a fractional frequency uncertainty of 10-17. With more experimental effort, the 223,225,226Ra+ clocks could be pushed to a projected performance reaching the 10-18 level.
Phys. Rev. A. 04/2011; 83(4).
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[show abstract]
[hide abstract]
ABSTRACT: We explore the potential of the electric quadrupole transitions
$7s\,^2S_{1/2}$ - $6d\,^2D_{3/2}$, $6d\,^2D_{5/2}$ in radium isotopes as
single-ion optical frequency standards. The frequency shifts of the clock
transitions due to external fields and the corresponding uncertainties are
calculated. Several competitive $^A$Ra$^+$ candidates with $A=$ 223 - 229 are
identified. In particular, we show that the transition
$7s\,^2S_{1/2}\,(F=2,m_F=0)$ - $6d\,^2D_{3/2}\,(F=0,m_F=0)$ at 828 nm in
$^{223}$Ra$^+$, with no linear Zeeman and electric quadrupole shifts, stands
out as a relatively simple case, which could be exploited as a compact, robust,
and low-cost atomic clock operating at a fractional frequency uncertainty of
$10^{-17}$. With more experimental effort, the $^{223,225,226}$Ra$^+$ clocks
could be pushed to a projected performance reaching the $10^{-18}$ level.
02/2011;
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O. O. Versolato,
G. S. Giri,
L. W. Wansbeek,
J. E. van den Berg,
D. J. van der Hoek,
K. Jungmann,
W. L. Kruithof,
C. J. G. Onderwater,
B. K. Sahoo,
B. Santra,
P. D. Shidling,
R. G. E. Timmermans,
L. Willmann, H. W. Wilschut
[show abstract]
[hide abstract]
ABSTRACT: As an important step towards an atomic parity violation experiment in one single trapped Ra$^+$ ion, laser spectroscopy experiments were performed with on-line produced short-lived $^{212,213,214}$Ra$^+$ ions. The isotope shift of the $6\,^2$D$_{3/2}$\,-\,$7\,^2$P$_{1/2}$ and $6\,^2$D$_{3/2}$\,-\,$7\,^2$P$_{3/2}$ transitions and the hyperfine structure constant of the $7\,^2$S$_{1/2}$ and $6\,^2$D$_{3/2}$ states in $^{213}$Ra$^+$ were measured. These values provide a benchmark for the required atomic theory. A lower limit of $232(4)$ ms for the lifetime of the metastable $6\,^2$D$_{5/2}$ state was measured by optical shelving. Comment: 4.2 pages, 6 figures, 2 tables.
03/2010;
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K. Piasecki,
T. Matulewicz,
N. Yahlali,
H Delagrange,
J Díaz,
D G D'Enterria,
F. Fernández,
A. Kugler,
H Löhner,
G Martínez García,
R. W. Ostendorf,
Y Schutz,
P Tlustý,
R. Turrisi,
V. Wagner, H. W. Wilschut
[show abstract]
[hide abstract]
ABSTRACT: Differential cross sections of neutral pions emitted in 181Ta + 197Au collisions at a beam energy of 39.5A MeV have been measured with the photon spectrometer TAPS. The kinetic energy and transverse momentum spectra of neutral pions cannot be properly described in the framework of the thermal model, nor when the reabsorption of pions is accounted for in a phenomenological model. However, high energy and high momentum tails of the pion spectra can be well fitted through thermal distributions with unexpectedly soft temperature parameters below 10 MeV. Comment: 16 pages (double-spaced), 5 figures; corrections after referee's comments and suggestions
09/2009;
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[show abstract]
[hide abstract]
ABSTRACT: Short lived $^{212,213,214}$Ra isotopes have been produced at the TRI$\mu$P facility in inverse kinematics via the fusion-evaporation reaction $^{206}$Pb+$^{12}$C at 8 MeV/u. Isotopes are separated from other reaction products online using the TRI$\mu$P magnetic separator. The energetic radium (Ra) isotopes at the exit of the separator were converted into low energy ions with a thermal ionizer. Ra isotopes have been identified by observing their $\alpha$ decay and life times. Comment: 9 pages including 4 figures and 1 table
02/2009;
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E. Traykov,
U. Dammalapati,
S. De,
O. C. Dermois,
L. Huisman,
K. Jungmann,
W. Kruithof,
A. J. Mol,
C. J. G. Onderwater,
A. Rogachevskiy,
M. da Silva e Silva,
M. Sohani,
O. Versolato,
L. Willmann, H. W. Wilschut
[show abstract]
[hide abstract]
ABSTRACT: The structures for the TRI$\mu$P facility have been completed and commissioned. At the facility radioactive nuclides are produced to study fundamental interactions and symmetries. An important feature is the possibility to trap radioactive atoms in order to obtain and hold a pure substrate-free sample for precision measurements. In the TRI$\mu$P facility a production target is followed by a magnetic separator, where radioactive isotopes are produced in inverse reaction kinematics. Separation up to 99.95% could be achieved for $^{21}$Na. A novel transmitting thermal ionizing device was developed to stop the energetic isotopes. Some 50% of stopped $^{21}$Na could be extracted and transported as low energy singly charged ions into a radio frequency quadrupole cooler and buncher with 35% transmission efficiency. The ions are transported lossless via a drift tube and a low energy electrostatic beam line into the experimental setup. Such ions can be neutralized on hot metal foils and the resulting atoms can be stored in a magneto-optical trap. The functioning of that principle was demonstrated with stable Na extracted from the thermal ionizer, radioactive beams will follow next.
10/2007;
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E. Traykov,
U. Dammalapati,
S. De,
O. C. Dermois,
L. Huisman,
K. Jungmann,
W. Kruithof,
A. J. Mol,
C. J. G. Onderwater,
A. Rogachevskiy,
M. da Silva e Silva,
M. Sohani,
O. Versolato,
L. Willmann, H. W. Wilschut
[show abstract]
[hide abstract]
ABSTRACT: An effective ion catcher is an important part of a radioactive beam facility that is based on in-flight production. The catcher stops fast radioactive products and emits them as singly charged slow ions. Current ion catchers are based on stopping in He and H$_2$ gas. However, with increasing intensity of the secondary beam the amount of ion-electron pairs created eventually prevents the electromagnetic extraction of the radioactive ions from the gas cell. In contrast, such limitations are not present in thermal ionizers used with the ISOL production technique. Therefore, at least for alkaline and alkaline earth elements, a thermal ionizer should then be preferred. An important use of the TRI$\mu$P facility will be for precision measurements using atom traps. Atom trapping is particularly possible for alkaline and alkaline earth isotopes. The facility can produce up to 10$^9$ s$^{-1}$ of various Na isotopes with the in-flight method. Therefore, we have built and tested a thermal ionizer. An overview of the operation, design, construction, and commissioning of the thermal ionizer for TRI$\mu$P will be presented along with first results for $^{20}$Na and $^{21}$Na.
10/2007;
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H. W. Wilschut,
U. Dammalapati,
S. De,
P. Dendooven,
O. Dermois,
K. Jungmann,
A. J. Mol,
C. J. G. Onderwater,
A. Rogachevskiy,
M. da Silva,
M. Sohani,
E. Traykov,
L. Willmann
[show abstract]
[hide abstract]
ABSTRACT: At KVI the technical structures for the TRIμP facility are nearly all in place. The aim of the project is to use radioactive ions to study fundamental interactions and
symmetries. We will measure β-recoil correlations in nuclear β decay. There the V,A structure of the Weak interaction may be violated. The second line of research is the search for a permanent
electric dipole moment in Ra, with a magnitude forbidden by the Standard Model. By trapping these radioactive nuclei in atom
traps a pure sample that can be manipulated facilitates these searches. The TRIμP facility consists of a production target and magnetic separator on the high energy side and a Radio-Frequency Quadrupole
(RFQ) cooler and buncher on the low energy side. An ion catcher stops the fast product nuclides and transport them into the
RFQ cooler. New technological approaches were implemented for several of these devices.
Hyperfine Interactions 12/2006; 174(1):97-102. · 0.21 Impact Factor
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E. Traykov,
A. Rogachevskiy,
U. Dammalapati,
P. Dendooven,
O. C. Dermois,
K. Jungmann,
C. J. G. Onderwater,
M. Sohani,
L. Willmann, H. W. Wilschut,
A. R. Young
[show abstract]
[hide abstract]
ABSTRACT: Efficient production of short-lived radioactive isotopes in inverse reaction kinematics is an important technique for various applications. It is particularly interesting when the isotope of interest is only a few nucleons away from a stable isotope. In this article production via charge exchange and stripping reactions in combination with a magnetic separator is explored. The relation between the separator transmission efficiency, the production yield, and the choice of beam energy is discussed. The results of some exploratory experiments will be presented. Comment: 10 pages, 4 figures, to be submitted to Nucl. Instr. and Meth
08/2006;
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G. P. A. Berg,
U. Dammalapati,
S. De,
S. Dean,
P. Dendooven,
O. Dermois,
K. Jungmann,
A. Rogachevskiy,
M. Sohani,
E. Traykov,
L. Willmann, H. W. Wilschut
[show abstract]
[hide abstract]
ABSTRACT: The TRIμP facility, under construction at KVI, requires the production and separation of short‐lived and rare isotopes. For this purpose, we have designed, constructed and commissioned a versatile magnetic separator that allows efficient injection into an ion catcher, i.e., gas‐filled stopper/cooler or thermal ionizer, from which a low energy radioactive beam will be extracted. These nuclides will be transported to atomic traps for precision experiments that may test the Standard Model. © 2006 American Institute of Physics
AIP Conference Proceedings. 04/2006; 831(1):403-405.
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L. Willmann,
G. P. Berg,
U. Dammalapati,
S. De,
P. Dendooven,
O. Dermois,
K. Jungmann,
A. Mol,
C. J. G. Onderwater,
A. Rogachevskiy,
M. Sohani,
E. Traykov, H. W. Wilschut
[show abstract]
[hide abstract]
ABSTRACT: The Tri$\mu$P facility at KVI is dedicated to provide short lived radioactive isotopes at low kinetic energies to users. It comprised different cooling schemes for a variety of energy ranges, from GeV down to the neV scale. The isotopes are produced using beam of the AGOR cyclotron at KVI. They are separated from the primary beam by a magnetic separator. A crucial part of such a facility is the ability to stop and extract isotopes into a low energy beamline which guides them to the experiment. In particular we are investigating stopping in matter and buffer gases. After the extraction the isotopes can be stored in neutral atoms or ion traps for experiments. Our research includes precision studies of nuclear $\beta$-decay through $\beta$-$\nu$ momentum correlations as well as searches for permanent electric dipole moments in heavy atomic systems like radium. Such experiments offer a large potential for discovering new physics. Comment: COOL05 Workshop, Galena, Il, USA, 18-23. Sept. 2005, 5 pages, 3 figures
02/2006;
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[show abstract]
[hide abstract]
ABSTRACT: K X-ray spectra of 40Ar + 51V fusion evaporation residues are measured in coincidence with -rays, protons and -particles. The spectra are separated into prompt components due to direct ionization of the target atom by the projectile and delayed components due to internal conversion of -rays. Ionization probabilities in half-trajectory collisions are deduced.
01/2006: pages 113-118;
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R. Ortega,
D. d'Enterria,
G. Martınez,
D. Baiborodin,
H. Delagrange,
J. Dıaz,
F. Fernández,
H. Löhner,
T. Matulewicz,
R. W. Ostendorf,
S. Schadmand,
Y. Schutz,
P. Tlusty,
R. Turrisi,
V. Wagner, H. W. Wilschut,
N. Yahlali
[show abstract]
[hide abstract]
ABSTRACT: Measured hard-photon multiplicities from second-chance nucleon-nucleon collisions are used in combination with a kinetic thermal
model to estimate the breakup times of excited nuclear systems produced in nucleus-nucleus reactions at intermediate energies.
The obtained nuclear breakup time for the 129Xe + natSn reaction at 50 A MeV is Δτ ≈ 100-300 fm/c for all reaction centralities. The lifetime of the radiating sources produced in seven other different heavy-ion reactions
studied by the TAPS experiment is consistent with Δτ ≈ 100 fm/c, such relatively long thermal photon emission times do not seemingly support the interpretation of nuclear breakup as due
to a fast spinodal process for the heavy nuclear systems studied.
European Physical Journal A 01/2006; 28(2):161-171. · 2.19 Impact Factor
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G. P. A. Berg,
O. C. Dermois,
U. Dammalapati,
P. Dendooven M. N. Harakeh,
K. Jungmann,
C. J. G. Onderwater,
A. Rogachevskiy,
M. Sohani,
E. Traykov,
L. Willmann, H. W. Wilschut
[show abstract]
[hide abstract]
ABSTRACT: The TRI$\mu$P facility, under construction at KVI, requires the production and separation of short-lived and rare isotopes. Direct reactions, fragmentation and fusion-evaporation reactions in normal and inverse kinematics are foreseen to produce nuclides of interest with a variety of heavy-ion beams from the superconducting cyclotron AGOR. For this purpose, we have designed, constructed and commissioned a versatile magnetic separator that allows efficient injection into an ion catcher, i.e., gas-filled stopper/cooler or thermal ionizer, from which a low energy radioactive beam will be extracted. The separator performance was tested with the production and clean separation of $^{21}$Na ions, where a beam purity of 99.5% could be achieved. For fusion-evaporation products, some of the features of its operation as a gas-filled recoil separator were tested. Comment: accepted by Nucl.Instr. Meth., final version
09/2005;
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[show abstract]
[hide abstract]
ABSTRACT: Experimental kinetic energy distributions and small-angle two-particle correlation functions involving deuterons and tritons are compared for 36Ar+ 112,124Sn collisions at E/A = 61 MeV (i.e. for systems similar in size, but with different isospin content). A larger triton yield is observed from the more neutron-rich system, as predicted by IBUU simulations, while the emission times of the light clusters are found to be the same for the two Sn-target systems. For both systems, the time sequence tau_{d} < tau_{p} < tau_{t}, is deduced for charged particles emitted from the intermediate velocity source.
08/2005;
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[show abstract]
[hide abstract]
ABSTRACT: The emission time sequence of neutrons, protons, and deuterons is deduced from velocity-gated two-particle correlation functions in E/A=61 MeV {sup 36}Ar+{sup 112,124}Sn reactions. A dependence of the emission sequence on the isospin of the emitting source is observed.
Physical Review. C, Nuclear Physics. 08/2004; 70(3).
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M Volkerts,
J C S Bacelar,
M J van Goethem,
M N Harakeh,
M Hoefman,
H Huisman,
N Kalantar-Nayestanaki,
S Kopecky,
H Löhner,
J G Messchendorp,
K Nakayama,
R W Ostendorf,
S Schadmand,
O Scholten, H W Wilschut
[show abstract]
[hide abstract]
ABSTRACT: Data on proton-neutron bremsstrahlung have been obtained from a measurement of the quasifree breakup channel in proton-deuteron bremsstrahlung. This high-precision measurement, with an incident proton energy of 190 MeV, is fully exclusive; i.e., the protons, the neutron, and the photon have been detected. The quasifree differential cross sections obtained are compared with microscopic calculations and calculations based on soft-photon models. There are sizable differences between the models and also between the models and the data obtained for this simple process.
Physical Review Letters 06/2004; 92(20):202301. · 7.37 Impact Factor
