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The ATHENA experiment is being built at CERN to produce and trap neutral antihydrogen. Here we give an overview of the plans to produce antihydrogen. The experiment must 1) trap the antiprotons produced by the CERN accelerators, 2) produce and trap positrons, 3) combine the two charge species into antihydrogen, and finally 4) detect the presence of the antihydrogen. In this paper we discuss how we intend to accomplish each of these steps. © 1999 American Institute of Physics. © 1999 American Institute of Physics

The Canadian Ophiostoma Genome Project, which was initiated in 2001, is a collaborative effort between research teams in four different universities. Its general objective is to conduct a large-scale identification and analysis of genes controlling important aspects of the life cycle of Ophiostomatoid fungi. To this end, several expressed sequence tag (EST) libraries were obtained for the Dutch elm disease pathogen Ophiostoma novo-ulmi and the sapstainer O. piceae, following partial, single-pass automated sequencing of complementary DNA clones. The largest EST library, prepared from yeast like cells of O. novo-ulmi grown at 24 °C, contains over 3,400 readable sequences and serves as a general reference library for Ophiostomatoid fungi. Smaller, specific EST libraries were constructed from mycelia of O. novo-ulmi grown at suboptimal temperatures, from perithecia formed in laboratory crosses, as well as from O. piceae grown on different carbon sources. Ongoing bioinformatic searches in public databases have so far identified over 750 Ophiostoma unique ESTs which show significant homology with other fungal genes of known function, although a high proportion of Ophiostoma ESTs are either orphans (no match to any known gene) or show homology to genes of unknown function. In addition to EST analysis, differential expression of selected genes and structural genomics are also being studied., El programa canadiense sobre el genoma de Ophiostoma, iniciado en 2001, es una colaboración entre equipos de investigación de cuatro universidades diferentes. Su objetivo general es el desarrollo de la identificación y análisis a gran escala de los genes que controlan algunos aspectos importantes del ciclo vital de los hongos de Ophiostoma. Con este fin, se ha obtenido diversas bibliotecas de marcadores de secuencias expresadas (bibliotecas EST) para la el patógeno de la grafiosis Ophiostoma novo-ulmi y para el hongo de tinción vascular O. piceae, seguido de una secuenciación automática parcial de un único paso de clones complementarios de ADN. La mayor biblioteca EST, preparada a partir de conidios de O. novo-ulmi cultivadas a 24 ºC, contiene más de 3.400 secuencias legíbles, y sirve como biblioteca de referencia para los hongos de Ophiostoma. Se han desarrollado bibliotecas específicas menores a partir de micelios de O. novo-ulmi cultivados a temperaturas sub-óptimas, a partir de los peritecios formados en cruces realizados en laboratorio, así como a partir de O. piceae cultivado en distintas fuentes de carbón. Las búsquedas bioinformáticas en bases de datos públicas han permitido identificar hasta ahora más de 750 EST exclusivos de Ophiostoma, lo que muestra una significativa homología con otros genes fúngicos de función conocida, aunque una alta proporción de los EST de Ophiostoma son o bien huérfanos (no relacionados con ningún gen conocido), o bien muestran homología con genes cuya función es desconocida. Además del análisis EST, la expresión diferencial de genes seleccionados y la estructura genómica están siendo también estudiadas.

The Canadian Ophiostoma Genome Project, which was initiated in 2001, is a collaborative effort between research teams in four different universities. Its general objective is to conduct a large-scale identification and analysis of genes controlling important aspects of the life cycle of Ophiostomatoid fungi. To this end, several expressed sequence tag (EST) libraries were obtained for the Dutch elm disease pathogen Ophiostoma novo-ulmi and the sapstainer O. piceae, following partial, single-pass automated sequencing of complementary DNA clones. The largest EST library, prepared from yeast like cells of O. novo-ulmi grown at 24 °C, contains over 3,400 readable sequences and serves as a general reference library for Ophiostomatoid fungi. Smaller, specific EST libraries were constructed from mycelia of O. novo-ulmi grown at suboptimal temperatures, from perithecia formed in laboratory crosses, as well as from O. piceae grown on different carbon sources. Ongoing bioinformatic searches in public databases have so far identified over 750 Ophiostoma unique ESTs which show significant homology with other fungal genes of known function, although a high proportion of Ophiostoma ESTs are either orphans (no match to any known gene) or show homology to genes of unknown function. In addition to EST analysis, differential expression of selected genes and structural genomics are also being studied. El programa canadiense sobre el genoma de Ophiostoma, iniciado en 2001, es una colaboración entre equipos de investigación de cuatro universidades diferentes. Su objetivo general es el desarrollo de la identificación y análisis a gran escala de los genes que controlan algunos aspectos importantes del ciclo vital de los hongos de Ophiostoma. Con este fin, se ha obtenido diversas bibliotecas de marcadores de secuencias expresadas (bibliotecas EST) para la el patógeno de la grafiosis Ophiostoma novo-ulmi y para el hongo de tinción vascular O. piceae, seguido de una secuenciación automática parcial de un único paso de clones complementarios de ADN. La mayor biblioteca EST, preparada a partir de conidios de O. novo-ulmi cultivadas a 24 ºC, contiene más de 3.400 secuencias legíbles, y sirve como biblioteca de referencia para los hongos de Ophiostoma. Se han desarrollado bibliotecas específicas menores a partir de micelios de O. novo-ulmi cultivados a temperaturas sub-óptimas, a partir de los peritecios formados en cruces realizados en laboratorio, así como a partir de O. piceae cultivado en distintas fuentes de carbón. Las búsquedas bioinformáticas en bases de datos públicas han permitido identificar hasta ahora más de 750 EST exclusivos de Ophiostoma, lo que muestra una significativa homología con otros genes fúngicos de función conocida, aunque una alta proporción de los EST de Ophiostoma son o bien huérfanos (no relacionados con ningún gen conocido), o bien muestran homología con genes cuya función es desconocida. Además del análisis EST, la expresión diferencial de genes seleccionados y la estructura genómica están siendo también estudiadas.

ASACUSA (\underline{A}tomic \underline{S}pectroscopy \underline{A}nd \underline{C}ollisions \underline{U}sing \underline{S}low \underline{A}ntiprotons) is a collaboration between a number of Japanese and European research institutions, with the goal of studying bound and continuum states of antiprotons with simple atoms.\\ Three phases of experimentation are planned for ASACUSA. In the first phase, we use the direct $\overline{p}$ beam from AD at 5.3 MeV and concentrate on the laser and microwave spectroscopy of the metastable antiprotonic helium atom, $\overline{p}$He$^+$, consisting of an electron and antiproton bound by the Coulomb force to the helium nucleus. Samples of these are readily created by bringing AD antiproton beam bunches to rest in helium gas. With the help of techniques developed at LEAR for resonating high precision laser beams with antiproton transitions in these atoms, ASACUSA achieved several of these first-phase objectives during a few short months of AD operation in 2000. Six atomic transitions of the metastable antiprotonic helium atom were thereby detected, three of which had not previously been observed. They included two transitions in the UV region of the spectrum. If we assume CPT invariance between the properties of the proton and the antiproton, as the theoretical calculations of transition frequencies do, the agreement is a signature of the excellence of theoretical treatments and calculation techniques of three-body Coulomb system including QED corrections. If, on the other hand, we take the calculated values to be correct, the agreement gives a stringent test of the fundamental constants of the antiproton and therefore tests the CPT theorem. Taking the second point of view, the results from the year 2000 together constrain any difference between the antiproton and proton charges and masses by a further factor of eight beyond the limits obtained by our PS205 experiments at LEAR.\\ The year 2000 also saw the first success of the ASACUSA triple-resonance laser/ microwave experiment. In this, both laser and microwave beams are to be used to measure the peculiar hyperfine structure of $\overline{p}$He$^+$, associated with the interaction of the electron spin magnetic moment with the orbital magnetic moment of the antiproton.\\ In phase 2 experiments, we add an RFQ linear decelerator (RFQD), which decelerates antiprotons from 5.3 MeV to few tens of keV. By enabling us to stop the antiprotons in very low density gas targets, this makes it possible to study in detail the imperfectly understood processes by which antiprotonic atoms are created. It also allows us to measure the antiproton's specific energy loss dE/dx in a variety of materials. After a test period with 5 MeV protons spent in a proton beam in Aarhus, the RFQD was installed in the AD beam line in November, and reached its design energy in the tens of keV range, with deceleration efficiency approaching the expected value of 45$\%$. The RFQD beam was then used to produce extensive new data on the stopping power of carbon and gold for antiprotons in the crucial unexplored region between 60 keV and 8 keV.\\ In phase 3, a multielectrode antiproton trap, another powerful tool for studying the antiproton, will be placed downstream of the RFQD. At the time of writing (March 2001), this had been assembled in the AD beam line after extensive testing in Tokyo. Antiprotons will be captured and cooled (by collisions with electrons) in the trap, and then extracted from it at and below $\sim 1 $ keV (eventually down to $\sim 10 $ eV). Such ultra-low-energy beams have hitherto been unavailable. They will allow us to produce antiprotonic atoms at such low target pressures that they are almost unperturbed by further collisions with target atoms. This will permit study of their production mechanisms in still closer detail, and the performance of extremely high precision spectroscopy.\\

Physical Review Letters

The study of CPT invariance with the highest achievable precision in all particle sectors is of fundamental importance for physics. Equally important is the question of the gravitational acceleration of antimatter. In recent years, impressive progress has been achieved at the Low Energy Antiproton Ring (LEAR) at CERN in capturing antiprotons in specially designed Penning traps, in cooling them to energies of a few milli-electron volts, and in storing them for hours in a small volume of space. Positrons have been accumulated in large numbers in similar traps, and low energy positron or positronium beams have been generated. Finally, steady progress has been made in trapping and cooling neutral atoms. Thus the ingredients to form antihydrogen at rest are at hand. We propose to investigate the different methods to form antihydrogen at low energy, and to utilize the best of these methods to capture a number of antihydrogen atoms sufficient for spectroscopic studies in a magnetostatic trap. Once antihydrogen atoms have been captured at low energy, spectroscopic methods can be applied to interrogate their atomic structure with extremely high precision and compare it to its normal matter counterpart, the hydrogen atom. Especially the 1S-2S transition, with a lifetime of the excited state of 122 ms and thereby a natural linewidth of 5 parts in 10 16, offers in principle the possibility to directly compare matter and antimatter properties at a level of 1 part in 10 18. Additionally, comparison of the gravitational masses of hydrogen and antihydrogen, using either ballistic or spectroscopic methods, can provide direct experimental tests of the Weak Equivalence Principle for antimatter at a high precision.

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 respectively ascribed to the (n,l)~=~(38,34)\,\rightarrow\,(37,33) and the (36 33)\,\rightarrow\,(35,32) transitions.