132 research outputs found
Perspectives for low energy antiproton physics at FAIR
The CRYRING accelerator, previously located at the Manne Siegbahn Laboratory
of Stockholm University, has been chosen by the FLAIR collaboration as the
central accelerator for the planned facility. It has been modified to allow for
high-energy injection and extraction and is capable of providing fast and slow
extracted beams of antiprotons and highly charged ions. It is currently being
installed at the ESR of GSI Darmstadt where it can be used with highly charged
ions. The future possibilities for its use with slow antiprotons will be
discussed.Comment: Proceedings of LEAP2013, 6 pages, 3 figures. Hyperfine Interactions
2014, The final publication is available at Springer via
http://dx.doi.org/10.1007/s10751-014-1058-
Precision spectroscopy of antiprotonic helium
Antiprotonic helium, a neutral exotic three-body system consisting of a
helium nucleus, an electron and an antiproton, is being studied at the
Antiproton Decelerator of CERN by the ASAUCSA collaboration. Using laser
spectroscopy of the energy levels of the antiproton in this system and
comparison to theory, a value of the antiproton-to-electron mass ratio with an
error of 3 ppb could be obtained. This result agrees with the most precise
measurement of the value of the proton and allows us to extract a limit of the
equality of the proton and antiproton charge and mass of 2 ppb. Using microwave
spectroscopy, the hyperfine structure of antiprotonic helium has been measured
to 30 ppm. Experimental improvements are expected to soon provide a new value
for the magnetic moment of the antiproton.Comment: Proceedings of the XLV International Winter Meeting on Nuclear
Physics, Bormio, Valtellina, January 14 - 21, 200
Prospects of In-Flight Hyperfine Spectroscopy of (Anti)Hydrogen for Tests of CPT Symmetry
The ground-state hyperfine splitting of antihydrogen promises one of the most
sensitive tests of CPT symmetry. The ASACUSA collaboration is pursuing a
measurement of this splitting in a Rabi-type experiment using a polarized beam
from a CUSP magnet at the Antiproton Decelerator of CERN. With the initial
intention of characterizing the Rabi apparatus, a polarized source of cold
hydrogen was built and the transition of hydrogen was measured to a
few ppb precision. A measurement of the transition is being prepared.
The availability of this beam opens the possibility to perform first
measurements of some coefficients within the nonminimal Standard-Model
Extension.Comment: Presented at the Seventh Meeting on CPT and Lorentz Symmetry,
Bloomington, Indiana, June 20-24, 201
Experimental perspectives on the matter-antimatter asymmetry puzzle: developments in electron EDM and antihydrogen experiments
In the search for clues to the matter-antimatter puzzle, experiments with
atoms or molecules play a particular role. These systems allow measurements
with very high precision, as demonstrated by the unprecedented limits down to
e.cm on electron EDM using molecular ions, and relative measurements
at the level of in spectroscopy of antihydrogen atoms. Building on
these impressive measurements, new experimental directions offer potentials for
drastic improvements. We review here some of the new perspectives in those
fields and their associated prospects for new physics searches
An atomic hydrogen beam to test ASACUSA's apparatus for antihydrogen spectroscopy
The ASACUSA collaboration aims to measure the ground state hyperfine
splitting (GS-HFS) of antihydrogen, the antimatter pendant to atomic hydrogen.
Comparisons of the corresponding transitions in those two systems will provide
sensitive tests of the CPT symmetry, the combination of the three discrete
symmetries charge conjugation, parity, and time reversal. For offline tests of
the GS-HFS spectroscopy apparatus we constructed a source of cold polarised
atomic hydrogen. In these proceedings we report the successful observation of
the hyperfine structure transitions of atomic hydrogen with our apparatus in
the earth's magnetic field.Comment: 8 pages, 4 figures, proceedings for conference EXA 2014 (Exotic Atoms
- Vienna
Hyperfine structure measurements of antiprotonic helium and antihydrogen
This paper describes measurements of the hyperfine structure of two antiprotonic atoms that are planned at the Antiproton Decelerator (AD) at CERN. The first part deals with antiprotonic helium, a three-body system of alpha-particle, antiproton and electron that was previously studied at LEAR. A measurement will test existing three-body calculations and may - through comparison with these theories - determine the magnetic moment of the antiproton more precisely than currently available, thus providing a test of CPT invariance. The second system, antihydrogen, consisting of an antiproton and a positron, is planned to be produced at thermal energies at the AD. A measurement of the ground-state hyperfine splitting, which for hydrogen is one of the most accurately measured physical quantities, will directly yield a precise value for the magnetic moment of the antiproton, and also compare the internal structure of proton and antiproton through the contribution of the magnetic size of the antiproton to the ground state hyperfine splitting.This paper describes measurements of the hyperfine structure of two antiprotonic atoms that are planned at the Antiproton Decelerator (AD) at CERN. The first part deals with antiprotonic helium, a three-body system of alpha-particle, antiproton and electron that was previously studied at LEAR. A measurement will test existing three-body calculations and may - through comparison with these theories - determine the magnetic moment of the antiproton more precisely than currently available, thus providing a test of CPT invariance. The second system, antihydrogen, consisting of an antiproton and a positron, is planned to be produced at thermal energies at the AD. A measurement of the ground-state hyperfine splitting, which for hydrogen is one of the most accurately measured physical quantities, will directly yield a precise value for the magnetic moment of the antiproton, and also compare the internal structure of proton and antiproton through the contribution of the magnetic size of the antiproton to the ground state hyperfine splitting.This paper describes measurements of the hyperfine structure of two antiprotonic atoms that are planned at the Antiproton Decelerator (AD) at CERN. The first part deals with antiprotonic helium, a three-body system of alpha-particle, antiproton and electron that was previously studied at LEAR. A measurement will test existing three-body calculations and may - through comparison with these theories - determine the magnetic moment of the antiproton more precisely than currently available, thus providing a test of CPT invariance. The second system, antihydrogen, consisting of an antiproton and a positron, is planned to be produced at thermal energies at the AD. A measurement of the ground-state hyperfine splitting, which for hydrogen is one of the most accurately measured physical quantities, will directly yield a precise value for the magnetic moment of the antiproton, and also compare the internal structure of proton and antiproton through the contribution of the magnetic size of the antiproton to the ground state hyperfine splitting.This paper describes measurements of the hyperfine structure of two antiprotonic atoms that are planned at the Antiproton Decelerator (AD) at CERN. The first part deals with antiprotonic helium, a three-body system of alpha-particle, antiproton and electron that was previously studied at LEAR. A measurement will test existing three-body calculations and may - through comparison with these theories - determine the magnetic moment of the antiproton more precisely than currently available, thus providing a test of CPT invariance. The second system, antihydrogen, consisting of an antiproton and a positron, is planned to be produced at thermal energies at the AD. A measurement of the ground-state hyperfine splitting, which for hydrogen is one of the most accurately measured physical quantities, will directly yield a precise value for the magnetic moment of the antiproton, and also compare the internal structure of proton and antiproton through the contribution of the magnetic size of the antiproton to the ground state hyperfine splitting.This paper describes measurements of the hyperfine structure of two antiprotonic atoms that are planned at the Antiproton Decelerator (AD) at CERN. The first part deals with antiprotonic helium, a three-body system of alpha-particle, antiproton and electron that was previously studied at LEAR. A measurement will test existing three-body calculations and may - through comparison with these theories - determine the magnetic moment of the antiproton more precisely than currently available, thus providing a test of CPT invariance. The second system, antihydrogen, consisting of an antiproton and a positron, is planned to be produced at thermal energies at the AD. A measurement of the ground-state hyperfine splitting, which for hydrogen is one of the most accurately measured physical quantities, will directly yield a precise value for the magnetic moment of the antiproton, and also compare the internal structure of proton and antiproton through the contribution of the magnetic size of the antiproton to the ground state hyperfine splitting.This paper describes measurements of the hyperfine structure of two antiprotonic atoms that are planned at the Antiproton Decelerator (AD) at CERN. The first part deals with antiprotonic helium, a three-body system of α-particle, antiproton and electron that was previously studied at LEAR. A measurement will test existing three-body calculations and may— through comparison with these theories— determine the magnetic moment of the antiproton more precisely than currently available, thus providing a test of CPT invariance. The second system, antihydrogen, consisting of an antiproton and apositron, is planned to be produced at thermal energies at the AD. A measurement of the ground-state hyperfine splitting , which for hydrogen is one of the most accurately measuredp hysical quantities, will directly yielda precise value for , andalso compare the internal structure of proton andan tiproton through the contribution of the magnetic size of the
- …