Possibility to study eta-mesic nuclei and photoproduction of slow eta-mesons at the GRAAL facility

A new experiment is proposed with the aim to study eta-mesic nuclei and low-energy interactions of eta with nuclei. Two decay modes of eta produced by a photon beam inside a nucleus will be observed, namely a collisional decay \eta N \to \pi N inside the nucleus and the radiative decay \eta \to \gamma \gamma outside. In addition, a collisional decay of stopped S_{11}(1535) resonance inside the nucleus, S_{11}(1535) N \to N N, will be studied. The experiment can be performed using the tagged photon beam at ESRF with the end-point energy 1000 MeV and the GRAAL detector which includes a high-resolution BGO calorimeter and a large acceptance lead-scintillator time-of-flight wall. Some results of simulation and estimates of yields are given.Comment: 20 pages, 19 figure

Traženje η-mezičkih jezgri fototvorbenim procesima

We present preliminary results of an experiment performed at the 1–GeV electron synchrotron of the Lebedev Physical Institute. Using the bremsstrahlung photon beam with the end-point energy of 650–850 MeV and the carbon target, correlated π +n pairs with opening angle hθπN i = 180◦ and energies hEπ+ i = 300 MeV, hEni = 100 MeV have been observed. They arise from the process γ + 12C → N + η(A − 1) → N + π +n + (A − 2) and provide evidence for the existence of 11 ηB and 11 ηC η-mesic nuclei.Snopovima kočnog zračenja najviše energije 650 i 850 MeV u Lebedevom fizičkom institutu opažale su se vezane tvorbe parova π +n, koji su nastali procesom γ+12C → N + η(A − 1) → N + π +n + (A − 2). Ti su procesi potvrda postojanja 11 ηB i 11 ηC η-mezičkih jezgri

Traženje η-mezičkih jezgri fototvorbenim procesima

We present preliminary results of an experiment performed at the 1–GeV electron synchrotron of the Lebedev Physical Institute. Using the bremsstrahlung photon beam with the end-point energy of 650–850 MeV and the carbon target, correlated π +n pairs with opening angle hθπN i = 180◦ and energies hEπ+ i = 300 MeV, hEni = 100 MeV have been observed. They arise from the process γ + 12C → N + η(A − 1) → N + π +n + (A − 2) and provide evidence for the existence of 11 ηB and 11 ηC η-mesic nuclei.Snopovima kočnog zračenja najviše energije 650 i 850 MeV u Lebedevom fizičkom institutu opažale su se vezane tvorbe parova π +n, koji su nastali procesom γ+12C → N + η(A − 1) → N + π +n + (A − 2). Ti su procesi potvrda postojanja 11 ηB i 11 ηC η-mezičkih jezgri

Effect of anodizing regimes on the volume expansion factor of the oxide films

The volume expansion factor of porous alumina, formed by through anodizing of an Al foil in ox- alic and sulphuric acid has been studied. The thickness of obtained porous alumina films was measured by a mechanical profilometer with a computer signal processing. The volume expansion factor of porous alumina varied from 1.35 to 1.65. Linear dependences were obtained for the vol- ume expansion factor of porous alumina versus the anodizing voltage and the ionic current density logarithm versus the inverse volume expansion factor. Unlike oxide formation in sulphuric acid, these dependences have two subsequential rectilinear regions in oxalic acid