G. Backenstoss

Bio: G. Backenstoss is an academic researcher from Katholieke Universiteit Leuven. The author has contributed to research in topics: Detector & Nucleon. The author has an hindex of 3, co-authored 5 publications receiving 49 citations.

Test of Quantum Electrodynamics by Muonic Atoms: An Experimental Contribution

Abstract: The large unexplained deviations of the experimental muonic 4-3 transitions in Ba and 5-4 transitions in Pb from calculations were found not to be existent. The absolute energies of these transitions agree, on the average, with theory to within 10 eV: The differences between experimental and calculated energies ${E}^{\mathrm{calc}}\ensuremath{-}{E}^{\mathrm{exp}}$ are +2\ifmmode\pm\else\textpm\fi{}13 and -2 \ifmmode\pm\else\textpm\fi{}12 eV for the ${\ensuremath{\mu}}^{\ensuremath{-}}$-Ba $4{f}_{\frac{5}{2}}\ensuremath{-}3{d}_{\frac{3}{2}}$ and $4{f}_{\frac{7}{2}}\ensuremath{-}3{d}_{\frac{5}{2}}$ transitions, respectively, and 10\ifmmode\pm\else\textpm\fi{}16 and -13\ifmmode\pm\else\textpm\fi{}14 eV for the ${\ensuremath{\mu}}^{\ensuremath{-}}$-Pb $5{g}_{\frac{7}{2}}\ensuremath{-}4{f}_{\frac{5}{2}}$ and $5{g}_{\frac{9}{2}}\ensuremath{-}4{f}_{\frac{7}{2}}$ transitions, respectively.

Possible evidence for narrow bound states related to the pp̄ system

Abstract: The exceptionally narrow, high mass nonstrange bosons clustered around the nucleon-antinucleon threshold are studied using a method based on the observation of monenergetic gamma rays accompanying the annihilation of stopped antiprotons in liquid hydrogen, where the anti p forms an antiprotonic atom with the target proton. In this way bound states were observed in the anti pp system for the first time. Three narrow structures at energies of 183, 216, and 420 MeV were seen with a confidence of 1, 2.5, and 1.8% respectively. The spectra are shown. Also applying the same methods to the anti p - He the case structure was found with 365 +- 26 MeV energy and 7.2% confidence. This would imply the formation of a bound state inside of nuclear matter. 47 references. (JFP)

The energy levels of muonic atoms

Abstract: The theory of muonic atoms is a complex and highly developed combination of nuclear physics, atomic physics, and quantum electrodynamics. Perhaps nowhere else in microscopic physics are such diverse branches so intimately intertwined and yet readily available for precise experimental verification or rejection. In the present review we summarize and discuss all of the most important components of muonic atom theory, and show in selected cases how this theory meets experimental measurements.

The Higgs boson

Abstract: A comprehensive review of the phenomenology of the conventional Higgs boson is presented. The fundamentals of the standard model of electroweak interactions are reviewed. Experimental limits on light Higgs bosons are assessed and prospects for further experimental searches are evaluated.

A Phenomenological Profile of the Higgs Boson

Abstract: A discussion is given of the production, decay and observability of the scalar Higgs boson H expected in gauge theories of the weak and electromagnetic interactions such as the Weinberg-Salam model. After reviewing previous experimental limits on the mass of the Higgs boson, we give a speculative cosmological argument for a small mass. If its mass is similar to that of the pion, the Higgs boson may be visible in the reactions π−p → Hn or γp → Hp near threshold. If its mass is ≲300 MeV, the Higgs boson may be present in the decays of kaons with a branching ratio O(10−7), or in the decays of one of the new particles: 3.7 → 3.1 + H with a branching ratio O(10−4). If its mass is ⩽4 GeV, the Higgs boson may be visible in the reaction pp → H + X, H → μ+μ−. If the Higgs boson has a mass ⩽2mμ, the decays H → e+e− and H → γγ dominate, and the lifetime is O(6 × 10−4 to 2 × 10−12) seconds. As thresholds for heavier particles (pions, strange particles, new particles) are crossed, decays into them become dominant, and the lifetime decreases rapidly to O(10−20) sec for a Higgs boson of mass 10 GeV. Decay branching ratios in principle enable the quark masses to be determined.

Is there evidence for the production of a new particle in heavy-ion collisions?

Abstract: The possibility of the production of a new neutral elementary particle in heavy-ion collisions is discussed.