Collision Induced Relaxations within the Antiprotonic Helium Hyperfine Structure (2009)
Pask, T., Barna, D., Dax, A., Friedreich, S., Hayano, R. S., Hori, M., ...
We report the first measurements of the inelastic spin exchange collision rate between the Hyperfine (HF) levels of antiprotonic helium. We measure the time dependent evolution of the (37, 35)...
Antiproton magnetic moment determined from the HFS of antiprotonic helium (2009)
Pask, T., Barna, D., Dax, A., Hayano, R. S., Hori, M., Horváth, D., ...
We report a determination of the antiproton magnetic moment, measured in a three-body system, independent of previous experiments. We present results from a systematic study of the hyperfine (HF)...
Antiproton magnetic moment determined from the HFS of pHe+ (2009)
Pask, T., Barna, D., Dax, A., Hayano, R. S., Hori, Masaki, Horváth, D., ...
Large-area imager of hydrogen leaks in fuel cells using laser-induced breakdown spectroscopy (2009)
Hori, Masaki, Hayano, R. S., Fukuta, M., Koyama, T., Nobusue, H., Tanaka, J.
A novel antiproton radial diagnostic based on octupole induced ballistic loss (2008)
Andresen, G. B., Bertsche, W., Bowe, P. D., Bray, C. C., Butler, E., Cesar, C. L., ...
We report results from a novel diagnostic that probes the outer radial profile of trapped antiproton clouds. The diagnostic allows us to determine the profile by monitoring the time-history of...
Production of antihydrogen at reduced magnetic field for anti-atom trapping (2008)
Andresen, G B, Bertsche, W, Boston, A, Bowe, P D, Cesar, C L, Chapman, S, ...
We have demonstrated production of antihydrogen in a 1$,$T solenoidal magnetic field. This field strength is significantly smaller than that used in the first generation experiments ATHENA (3$,$T)...
Compression of Antiproton Clouds for Antihydrogen Trapping (2008)
Andresen, G. B., Bertsche, W., Bowe, P. D., Bray, C. C., Butler, E., Cesar, C. L., ...
Control of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report the first detailed measurements of the radial manipulation of antiproton clouds, including...
Particle Physics Aspects of Antihydrogen Studies with ALPHA at CERN (2008)
Andresen, G. B., Bertsche, W., Bowe, P. D., Bray, C. C., Butler, E., ...
We discuss aspects of antihydrogen studies, that relate to particle physics ideas and techniques, within the context of the ALPHA experiment at CERN's Antiproton Decelerator facility. We review the...
Improved Study of the Antiprotonic Helium Hyperfine Structure (2008)
Pask, T., Barna, D., Dax, A., Hayano, R. S., Hori, M., Horváth, D., ...
We report the initial results from a systematic study of the hyperfine (HF) structure of antiprotonic helium (n,l) = (37,~35) carried out at the Antiproton Decelerator (AD) at CERN. We performed a...
Production of Slow Protonium in Vacuum (2008)
Zurlo, N., Amoretti, M., Amsler, C., Bonomi, G., Carraro, C., Cesar, C. L., ...
We describe how protonium, the quasi-stable antiproton-proton bound system, has been synthesized following the interaction of antiprotons with the molecular ion H$_2^+$ in a nested Penning trap...
Collisional Effects on the Antiprotonic Helium Hyperfine Structure Measurement (2008)
Pask, T., Barna, D., Dax, A., Hayano, R. S., Hori, Masaki, Horváth, D., ...
Improved study of the antiprotonic helium hyperfine structure (2008)
Pask, T., Barna, D., Dax, A., Hayano, R. S., Hori, M., Horváth, D., ...
$\Lambda N$ correlations from the stopped $K^-$ reaction on ${}^4$He (2007)
Suzuki, T., Bhang, H., Chiba, J., Choi, S., Fukuda, Y., Hanaki, T., ...
We have investigated correlations of coincident $\Lambda N$ pairs from the stopped $K^-$ reaction on ${}^4$He, and clearly observed $\Lambda p$ and $\Lambda n$ branches of the two-nucleon absorption...
EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CERN--PPE/94-213 7 December 1994 (2007)
Phase And Density, E. Widmann, I. Sugai, T. Yamazaki, R. S. Hayano, M. Iwasaki, ...
Systematic studies of the phase and density dependence of the delayed annihilation time spectra of antiprotons (DATS) in gaseous, liquid and solid helium have been performed using the Low Energy...
$\Lambda d$ correlations from the $^4$He(stopped-$K^-$,$d$) reaction (2007)
Suzuki, T., Bhang, H., Chiba, J., Choi, S., Fukuda, Y., Hanaki, T., ...
We have observed an intense high-energy component in an inclusive $^4$He(stopped $K^-$, $d$) spectrum. For back-to-back $\Lambda d$ pairs a prominent event cluster has been found just below the...
Evidence For The Production Of Slow Antiprotonic Hydrogen In Vacuum (2007)
Zurlo, N., Amoretti, M., Amsler, C., Bonomi, G., Carraro, C., Cesar, C. L., ...
We present evidence showing how antiprotonic hydrogen, the quasistable antiproton-proton (pbar-p) bound system, has been synthesized following the interaction of antiprotons with the hydrogen...
Search for strange tribaryon states in the inclusive ^4He(K^{-}_{stopped}, p) reaction (2007)
Sato, M., Bhang, H., Chiba, J., Choi, Seonho, Fukuda, Y., Hanaki, T., ...
A search for tribaryon states was performed at KEK-PS. We adopted the $^4$He($K^-_{stopped}, p)$ reaction to populate the states with strangeness -1, charge 0 and isospin 1. No significant narrow...
Precision measurement of the $3d \to 2p$ x-ray energy in kaonic $^4$He (2007)
Okada, S., Beer, G., Bhang, H., Cargnelli, M., Chiba, J., Choi, Seonho, ...
We have measured the Balmer-series x-rays of kaonic $^4$He atoms using novel large-area silicon drift x-ray detectors in order to study the low-energy $\bar{K}$-nucleus strong interaction. The energy...
Search for a kaonic nuclear state via $^4$He$(K^-, N)$ (2007)
Iwasaki, M., Bhang, H., Chiba, J., Choi, S., Fukuda, Y., Hanaki, T., ...
Very recently, we have performed a couple of experiments, {\it{KEK PS-E549/E570}}, for the detailed study of the strange tribaryon $S^0(3115)$ obtained in {\it{KEK PS-E471}}. These experiments were...
Towards Antihydrogen Confinement with the ALPHA Antihydrogen Trap (2007)
Fujiwara, M. C., Andresen, G., Bertsche, W., Boston, A., Bowe, P. D., Cesar, C. L., ...
ALPHA is an international project that has recently begun experimentation at CERN's Antiproton Decelerator (AD) facility. The primary goal of ALPHA is stable trapping of cold antihydrogen atoms with...
Positron plasma control techniques for the production of cold antihydrogen (2007)
Funakoshi, R., Amoretti, M., Bonomi, G., Bowe, P. D., Canali, C., Carraro, C., ...
An observation of a clear dependence of antihydrogen production on positron plasma shapes is reported. For this purpose a plasma control method has been developed combining the plasma rotating-wall...
G B Andresen, W Bertsche, S Chapman, M Charlton, A Deutsch, M C Fujiwara, ...
We have demonstrated production of antihydrogen in a 1 T solenoidal magnetic field. This field strength is significantly smaller than that used in the first generation experiments ATHENA (3 T) and...
Cold-Antimatter Physics (2005)
Amoretti, ATHENA Collaboration: M., Amsler, C., Bonomi, G., Bowe, P. D., Canali, C., Carraro, C., ...
The CPT theorem and the Weak Equivalence Principle are foundational principles on which the standard description of the fundamental interactions is based. The validity of such basic principles should...
A search for deeply bound kaonic nuclear states (2005)
Suzuki, T., Bhang, H., Franklin, G., Gomikawa, K., Hayano, R. S., Hayashi, T., ...
We have measured proton and neutron energy spectra by stopping negative kaons on liquid helium4. Two distinct peak structures were found on both spectra, which were assigned to the formation of new...
Barna, D, Caspers, Friedhelm, Eades, John, Gilg, H, Hayano, R S, Hori, Masaki, ...
For the precise measurement of the hyperfine structure of antiprotonic helium microwave radiation of 12.9 GHz frequency is needed, tunable over ±100 MHz. A cylindrical microwave cavity is used whose...
Barna, D, Caspers, Friedhelm, Eades, John, Gilg, H, Hayano, R S, Hori, Masaki, ...
For the precise measurement of the hyperfine structure of antiprotonic helium microwave radiation of 12.9 GHz frequency is needed, tunable over ±100 MHz. A cylindrical microwave cavity is used whose...
ATHENA : First Production of Cold Antihydrogen and Beyond (2004)
Kellerbauer, A G, Amoretii, M, Amsler, Claude, Bonomi, G, Bowe, P, Canali, C, ...
Atomic systems of antiparticles are the laboratories of choice for tests of CPT symmetry with antimatter. The ATHENA experiment was the first to report the production of copious amounts of cold...
ATHENA -- First Production of Cold Antihydrogen and Beyond (2004)
Kellerbauer, ATHENA Collaboration: A., Amoretti, M., Amsler, C., Bonomi, G., Bowe, P. D., Canali, C., ...
Atomic systems of antiparticles are the laboratories of choice for tests of CPT symmetry with antimatter. The ATHENA experiment was the first to report the production of copious amounts of cold...
Production of Cold Antihydrogen with ATHENA for Fundamental Studies (2004)
Kellerbauer, A G, Kellerbauer, A G, Amoretti, M, Amsler, Claude, Bonomi, G, Bowe, P, ...
Since the beginning of operations of the CERN Antiproton Decelerator in July 2000, the successful deceleration, storage and manipulation of antiprotons has led to remarkable progress in the...
Production of Cold Antihydrogen with ATHENA for Fundamental Studies (2004)
Kellerbauer, ATHENA Collaboration: A., Amoretti, M., Amsler, C., Bonomi, G., Bowe, P. D., Canali, C., ...
Since the beginning of operations of the CERN Antiproton Decelerator in July 2000, the successful deceleration, storage and manipulation of antiprotons has led to remarkable progress in the...
The ATHENA Antihydrogen Apparatus (2004)
Amoretti, M, Amsler, Claude, Bonomi, G, Bouchta, A, Bowe, P, Carraro, C, ...
The ATHENA apparatus that recently produced and detected the first cold antihydrogen atoms is described. Its main features, which are described herein, are: an external positron accumulator, making...
The First Cold Antihydrogen (2004)
Fujiwara, M C, Amoretti, M, Amsler, Claude, Bonomi, G, Bouchta, A, Bowe, P, ...
Antihydrogen, the atomic bound state of an antiproton and a positron, was produced at low energy for the first time by the ATHENA experiment, marking an important first step for precision studies of...
The First Cold Antihydrogen (2004)
Fujiwara, M. C., Amoretti, M., Amsler, C., Bonomi, G., Bouchta, A., Bowe, P. D., ...
Antihydrogen, the atomic bound state of an antiproton and a positron, was produced at low energy for the first time by the ATHENA experiment, marking an important first step for precision studies of...
Three Dimensional Annihilation Imaging of Antiprotons in a Penning Trap (2004)
Fujiwara, M. C., Amoretti, M., Bonomi, G., Bouchta, A., Bowe, P. D., Carraro, C., ...
We demonstrate three-dimensional annihilation imaging of antiprotons trapped in a Penning trap. Exploiting unusual feature of antiparticles, we investigate a previously unexplored regime in particle...
Systematic study of the decay rates of antiprotonic helium states (2004)
Yamaguchi, H, Hayano, R S, Ishikawa, T, Sakaguchi, J, Widmann, E, Eades, John, ...
A systematic study of the decay rates of antiprotonic helium (\pbhef and \pbhet) at CERN AD (Antiproton Decelerator) has been made by a laser spectroscopic method. The decay rates of some of its...
Systematic study of the decay rates of antiprotonic helium states (2004)
Yamaguchi, H., Hayano, R. S., Ishikawa, T., Sakaguchi, J., Widmann, E., Eades, J., ...
A systematic study of the decay rates of antiprotonic helium (\pbhef and \pbhet) at CERN AD (Antiproton Decelerator) has been made by a laser spectroscopic method. The decay rates of some of its...
Detection of antihydrogen annihilations with a Si-micro-strip and pure CsI detector (2004)
Johnson, I, Amoretti, M, Amsler, Claude, Bazzano, G, Bonomi, G, Bouchta, A, ...
In 2002, the ATHENA collaboration reported the creation and detection of cold (~15 K) antihydrogen atoms [1]. The observation was based on the complete reconstruction of antihydrogen annihilations,...
Suzuki, K., Fujita, M., Geissel, H., Gilg, H., Gillitzer, C. G., Hayano, R. S., ...
This version is available at the following Publisher URL: http://prl.aps.org
Indication of a strange tribaryon S^+ from the ^4He(stopped K^-,n) reaction (2003)
Iwasaki, M., Suzuki, T., Bhang, H., Franklin, G., Gomikawa, K., Hayano, R. S., ...
We measured the neutron time-of-flight spectrum in the ^4He(stopped K^-, n) reaction by stopping negative kaons in a superfluid helium target. A clear enhancement was observed in the neutron...
Positron plasma diagnostics and temperature control for antihydrogen production (2003)
Amoretti, M, Amsler, Claude, Bonomi, G, Bouchta, A, Bowe, P, Carraro, C, ...
Production of antihydrogen atoms by mixing antiprotons with a cold, confined, positron plasma depends critically on parameters such as the plasma density and temperature. We discuss non-destructive...
Positron plasma diagnostics and temperature control for antihydrogen production (2003)
Amoretti, ATHENA Collaboration: M., Amsler, C., Bonomi, G., Bouchta, A., Bowe, P. D., Carraro, C., ...
Production of antihydrogen atoms by mixing antiprotons with a cold, confined, positron plasma depends critically on parameters such as the plasma density and temperature. We discuss non-destructive...
First Production and Detection of Cold Antihydrogen Atoms (2003)
Fujiwara, M C, Amoretti, M, Amsler, Claude, Bonomi, G, Bouchta, A, Bowe, P, ...
The ATHENA experiment recently produced the first atoms of cold antihydrogen. This paper gives a brief review of how this was achieved.
First Production and Detection of Cold Antihydrogen Atoms (2003)
Fujiwara, M. C., Amoretti, M., Amsler, C., Bonomi, G., Bouchta, A., Bowe, P., ...
The ATHENA experiment recently produced the first atoms of cold antihydrogen. This paper gives a brief review of how this was achieved.
Analog Cherenkov detectors used in laser spectroscopy experiments on antiprotonic helium (2003)
Hori, Masaki, Yamashita, K, Hayano, R S, Yamazaki, T
We describe some acrylic Cherenkov detectors read out by gateable fine-mesh photomultipliers, used in laser spectroscopy experiments of metastable antiprotonic helium (pbarHe+) atoms carried out at...
Yamaguchi, H, Eades, John, Hayano, R S, Hori, Masaki, Horváth, D, Ishikawa, T, ...
We have measured twelve transition frequencies of the antiprotonic helium atom (pbar-He+) with precisions of 0.1--0.2 ppm using a laser spectroscopic method. The agreement between the experiment and...
Yamaguchi, H., Eades, J., Hayano, R. S., Hori, M., Horvath, D., Ishikawa, T., ...
We have measured twelve transition frequencies of the antiprotonic helium atom (pbar-He+) with precisions of 0.1--0.2 ppm using a laser spectroscopic method. The agreement between the experiment and...
Suzuki, K., Fujita, M., Geissel, H., Gilg, H., Gillitzer, A., Hayano, R. S., ...
Deeply bound 1s states of $\pi^-$ in $^{115,119,123}$Sn were preferentially observed using the Sn($d$,$^3$He) pion-transfer reaction under the recoil-free condition. The 1s binding energies and...
Production and detection of cold antihydrogen atoms (2002)
Amoretti, M, Amsler, Claude, Bonomi, G, Bouchta, A, Bowe, P, Carraro, C, ...
A theoretical underpinning of the standard model of fundamental particles and interactions is CPT invariance, which requires that the laws of physics be invariant under the combined discrete...
Widmann, E, Hayano, R S, Ishikawa, T, Sakaguchi, J, Tasaki, T, Yamaguchi, H, ...
Using a newly developed laser-microwave-laser resonance method, we observed a pair of microwave transitions between hyperfine levels of the $(n,L)=(37,35)$ state of antiprotonic helium. This...
Widmann, E., Hayano, R. S., Ishikawa, T., Sakaguchi, J., Tasaki, T., Yamaguchi, H., ...
Using a newly developed laser-microwave-laser resonance method, we observed a pair of microwave transitions between hyperfine levels of the $(n,L)=(37,35)$ state of antiprotonic helium. This...
Producing Slow Antihydrogen for a Test of CPT Symmetry with ATHENA (2002)
Fujiwara, M C, Amoretti, M, Amsler, Claude, Bendiscioli, G, Bonomi, G, Bouchta, A, ...
The ATHENA experiment at the Antiproton Decelerator facility at CERN aims at testing CPT symmetry with antihydrogen. An overview of the experiment, together with preliminary results of development...
Geissel, H., Gilg, H., Gillitzer, C. G., Hayano, R. S., Hirenzaki, S., Itahashi, K., ...
This version is available at the following Publisher URL: http://prl.aps.org
Hyperfine Structure Measurements of Antiprotonic Helium and Antihydrogen (2001)
Widmann, E, Eades, John, Hayano, R S, Hori, Masaki, Horváth, D, Ishikawa, T, ...
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...
Hyperfine Structure Measurements of Antiprotonic Helium and Antihydrogen (2001)
Widmann, E., Eades, J., Hayano, R. S., Hori, M., Horvath, D., Ishikawa, T., ...
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...
Hyperfine Structure Measurements of Antiprotonic Helium and Antihydrogen (2001)
Widmann, E, Eades, John, Hayano, R S, Hori, Masaki, Horváth, D, Ishikawa, T, ...
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...
Gilg, H., Gillitzer, C. G., Knülle, M., Münch, W., Schott, W., Kienle, P., ...
This version is available at the following Publisher URL: http://prc.aps.org
Itahashi, K., Oyama, K., Hayano, R. S., Gilg, H., Gillitzer, C. G., Knülle, M., ...
This version is available at the following Publisher URL: http://prc.aps.org
Yamazaki, T, Hayano, R S, Itahashi, K, Oyama, K, Gillman, A R, Gilg, H, ...
Formation of $\eta$-mesic Nuclei Using the Recoilless (d,$^3$He) Reaction (1998)
Hayano, R. S., Hirenzaki, S., Gillitzer, A.
We propose to use the recoilless (d,$^3$He) reaction to produce $\eta$-mesic nuclei. This reaction has been used to observe deeply bound pionic states and proven to be powerful recently. We calculate...
Ketzer, B, Hartmann, F J, Von Egidy, T, Maierl, C, Pohl, R, Eades, John, ...
Laser resonance transitions between normally metastable states of antiprotonic helium atoms were induced making use of state dependent quenching effects caused by trace admixtures of \mbox{H$_2$}\ to...
Ketzer, B, Hartmann, F J, Von Egidy, T, Maierl, C, Pohl, R, Eades, John, ...
Laser resonance transitions between normally metastable states of antiprotonic helium atoms were observed making use of state dependent quenching effects caused by small admixtures of \htwo\...
Yamazaki, T, Widmann, E, Eades, John, Kumakura, M, Morita, N, Torii, H A, ...
Very weak laser resonances of unfavoured transitions $(n,l) \rightarrow (n+1,l-1)$ have been observed in metastable \={p}$^4$He$^+$ atoms by using a pulsed antiproton beam. The observed wavelengths...
Yamazaki, T, Widmann, E, Eades, John, Kumakura, M, Morita, N, Torii, H A, ...
Very weak laser resonances of unfavoured transitions $(n,l) \rightarrow (n+1,l-1)$ have been observed in metastable \={p}$^4$He$^+$ atoms by using a pulsed antiproton beam. The observed wavelengths...
Antihydrogen production and precision experiments (1996)
Holzscheiter, M H, Bendiscioli, G, Bertin, A, Bollen, G, Bruschi, M, Cesar, C L, ...
Hayano, R S, Ishikawa, T, Tamura, H, Torii, H A, Hori, Masaki, Maas, F E, ...
A new laser-induced resonant transition in the $v=n-l-1=2$ metastable cascade of antiprotonic $^4$He atoms has been found by using a double resonance technique. This was done by setting the first...
Discovery of deeply bound $\pi^{-}$ states in the $^{208}Pb$ (d, $^3{He}$) reaction (1996)
Yamazaki, T, Hayano, R S, Itahashi, K, Oyama, K, Gillman, A R, Gilg, H, ...
Torii, H A, Hori, Masaki, Ishikawa, T, Maas, F E, Hayano, R S, Morita, N, ...
Laser-induced resonant transitions in metastable antiprotonic ^3He atoms have been found. The observed transitions at wavelengths 593.388 \pm 0.001~nm and at 463.947 \pm 0.002~nm have been...
Effects of impurity atoms and molecules on the lifetime of antiprotonic helium atoms (1995)
Widmann, E, Sugai, I, Yamazaki, T, Hayano, R S, Iwasaki, M, Nakamura, S N, ...
Delayed annihilation time spectra of antiprotons (DATS) in room temperature helium gas have been studied as a function of the concentration of admixed noble gases (Ne, Ar, Kr, Xe) as well as...
Ketzer, B, Hartmann, F J, Daniel, H, Von Egidy, T, Niestroj, A, Schmid, S, ...
The delayed annihilation time spectra (DATS) of antiprotonic helium atoms have been studied in isotopically pure low temperature ^3He and ^4He gas at various densities. The DATS taken at 5.8~K and...
Laser studies of the decay chain of metastable antiprotonic helium atoms (1994)
Hayano, R S, Maas, F E, Torii, H A, Morita, N, Kumakura, M, Yamazaki, T, ...
Delayed annihilation of antiprotons in helium gas (1993)
Nakamura, S N, Hayano, R S, Iwasaki, M, Shigaki, K, Widmann, E, Yamazaki, T, ...
Morita, N, Kumakura, M, Yamazaki, T, Widmann, E, Masuda, H, Sugai, I, ...
A naturally occurring trap for antiprotons (1993)
Eades, John, Morita, N, Ito, T M, Ito, Y, Kawachi, A, Nakamura, S N, ...