[en] The purpose of the symposium is to study the implications of the Standard Model (and its extensions) in the realm of low-energy physics. The atomic nucleus constitutes a laboratory where these questions can be investigated. Low- and medium-energy accelerators, reactors and other facilities continue to play an important role in this field. The electroweak sector of the Standard Model has benefited much from these investigations. Weak and electromagnetic interactions are also used to probe nuclear and hadronic structures and also new states of nuclear matter (the strong sector of the Standard Model). These studies cannot be dissociated from the fundamental questions raised in the realm of high-energy physics, astrophysics and cosmology

[en] In this paper experiments performed by TRIUMF physicists on rare decays of the pion, muon and kaon are discussed in relation with the physics beyond the Standard Model

[en] Rare decay modes of the pion and muon are an abundant source of information about elementary particles and their interactions. The problems of muon-electron universality, muon number non-conservation and the radiative decay of the pion are discussed. (orig.)

[en] Experiment E-246, which is in preparation at KEK, will search for a transverse polarization of the muon in the K⁺ → π⁰μ⁺ν (K_μ3) decay. This component of the polarization vector violates time-reversal invariance in a non-standard way (it does not exist in the standard model). The final-state electromagnetic interaction gives a negligible contribution. Therefore, the observation of a transverse polarization of the muon in the K_μ3 decay would be a clear signal of new physics. Positive kaons are stopped in a segmented target. The muon is tracked in a magnetic spectrometer (toroidal magnet and drift chambers). The neutral pion is detected in a segmented CsI calorimeter. The polarimeter makes use of the positron asymmetry in muon decay. The apparatus is designed to suppress the effect of the in-plane components of the polarization vector, and to eliminate spurious asymmetries. The apparatus will also be used to search for a transverse polarization of the muon in the K⁺ → γμ⁺ν decay. (author)

[en] Symmetries such as P (parity), C (particle-antiparticle conjugation), T (time reversal), B (baryon number), L (lepton number and Li (partial lepton number) are studied in this lecture. Essentially physics enclosed in formulas and theorems are described, together with principles which are basis of experimental methods. Several historical experiments and some current developments are chosen. The different subjects are presented in the theoretical frame of the standard model

[en] Full text: I will report on experiments which have been performed at the Japanese National Laboratory KEK, Tsukuba, Japan, using stopped kaons from the 12 GeV synchrocyclotron. The Standard Model (SM) of particle physics has been extremely successful in describing a broad range of phenomena, sometimes with extreme accuracy. However, we are not completely satisfied with the SM, for several reasons. And we are hoping to observe some 'physics beyond the Standard Model'. An attractive possibility is to search for observables which are not present (or are negligibly small) in the SM. An example is the transverse polarization of the muon in the decays K⁺→π⁰μ⁺ν and K⁺→γμ⁺ν, the first one being particularly attractive because it is practically exempt from final-state interaction. The experimental method and experimental set-up will be described and the upper limits obtained will be presented. (author)

[en] The E614 experiment at TRIUMF is designed to measure very accurately the muon-decay parameters ρ, P_μξ, δ and to improve precision on the parameter η. The source will be surface muons (positive muons) with 100% longitudinal polarisation. The positrons from μ⁺ decay will be momentum analysed with a chamber system placed in a very uniform magnetic field. The aim of the experiment is to search for possible deviations of the parameter values from the predictions of the Standard Model. (author)

[en] The title needs some explanation: TRIUMF = TRI-University Meson Factory: the meson factory of the three universities Twist = TRIUMF Weak Interaction Symmetry Test The TRIUMF Laboratory was founded in 1968 by three universities of the province of British Columbia, Canada: . The University of British Columbia (UBC), in the city of Vancouver, . Simon Fraser University (SFU) also in the city of Vancouver, . The University of Victoria (UVIC) in the city of Victoria. The University of Alberta (in Edmonton, province of Alberta) joined the TRIUMF consortium almost immediately. The name of the laboratory (TRIUMF) did not change. Several other Canadian universities have joined TRIUMF, which can now be considered as a national laboratory in Canada. For more information consult the TRIUMF web site: www.TRIUMF.ca. Universities affiliated with TRIUMF (from west to east): . University of Victoria, Victoria, British Columbia . UBC (University of British Columbia), Vancouver, British Columbia . SFU (Simon Fraser University), Vancouver, British Columbia . University of Alberta, Edmonton, Alberta . University of Manitoba, Winnipeg, Manitoba . University of Guelph, Guelph, Ontario . University of Toronto, Toronto, Ontario . York University, Toronto, Ontario . Queen's University, Kingston, Ontario . Carleton University, Ottawa, Ontario . University Le de Montreal, Montreal, Quebe Associate members (from west to east): . University of Northern British Columbia, Prince George, British Columbia . University of Calgary, Calgary, Alberta . University of Regina, Regina, Saskatchewan . University of Winnipeg, Winnipeg, Manitoba . McMaster University, Hamilton, Ontario . Saint Mary's University, Halifax, Nova Scotia TRIUMF activities outside Canada: At CERN (Geneva): participation in the ATLAS group activities with the LHC. At JPARC (Japan Proton Accelerator Research complex): - Participation in the TREK experiment: TREK = Time Reversal Experiment with Kaons, a measurement of the transverse polarization of the muon in the K⁺ →π⁰μ⁺ν decay: search for physics beyond the Standard Model. - Participation in activities on neutrino physics. Other TRIUMF activities in Vancouver: TRIUMF collaborates with Canadian industrial companies like MDS Nordion (see www.nordion.com). (Nordion is a world leader in providing medical isotopes). TRIUMF is investigating the possibility of producing molybdenum isotopes by using accelerators. Canada has been the main provider of molybdenum isotopes by using the Chalk River reactors. There have been some problems which have imposed the shut-down of several reactors

No abstract available

[en] Why is the muon so important in particle physics? - We now have particle accelerators which can produce high-intensity and high-quality muon beams. Further improvements are on the way. - The muon does not have strong interactions. It is therefore an ideal particle to explore the field of electroweak interactions. - The properties of the muon: mass, lifetime, magnetic moment, have already been measured to great precision and future improvements are still possible. - The decay modes of the muon are an important source of information: 1) A precise study of the main decay mode gives access to the Michel parameters which have definite values in the Standard Model. 2) Especially interesting are the decays which are forbidden in the Standard Model. Presently, very stringent upper limits have been obtained and further progress is expected. These upper limits can be used to constrain theories of electroweak interactions beyond the Standard Model