Search results for "Tipa"
showing 10 items of 596 documents
Anti-Zeno-based dynamical control of the unfolding of quantum Darwinism
2020
We combine the collisional picture for open system dynamics and the control of the rate of decoherence provided by the quantum (anti-)Zeno effect to illustrate the temporal unfolding of the redundant encoding of information into a multipartite environment that is at the basis of Quantum Darwinism, and to control it. The rate at which such encoding occurs can be enhanced or suppressed by tuning the dynamical conditions of system-environment interaction in a suitable and remarkably simple manner. This would help the design of a new generation of quantum experiments addressing the elusive phenomenology of Quantum Darwinism and thus its characterization.
Polarization analysis of $\bar{p}$ produced in pA collisions
2019
A quite simple procedure for the generation of a polarized antiproton beam could be worked out if antiprotons are produced with some polarization. In order to investigate this possibility measurements of the polarization of produced antiprotons have been started at a CERN/PS test beam. The polarization will be determined from the asymmetry of the elastic antiproton scattering at a liquid hydrogen target in the CNI region for which the analyzing power is well known. The data are under analysis and an additional measurement is done in 2018. Details on the experiment and the ongoing data analysis will be given.
Status of the analysis for the search of polarization in the antiproton production process
2016
The P-349 experiment aims to test whether for antiprotons the production process itself can be a source of polarization in view of the preparation of a polarized antiproton beam. In this article we present the details of performed measurements and report on the status of the ongoing analysis.
Positron annihilation studies of binary Ni-based alloys
1987
Positron annihilation studies of Ni–1 at. % X (X = Pb, In and Zn) alloys have been performed. The experimentally observed changes in the parameters connecting the shape of angular correlation curve with the kind and concentration of crystal lattice defects are correlated with the values of the vacancy-solute binding energy calculated from the vacancy model of melting.
Nonlinear density dependence of the positron decay rate in helium
1980
The decay rate of thermalized positrons in helium is calculated as a function of the fluid density, incorporating the multiple scattering of the positron off the atoms. The obtained nonlinearity agrees with experimental data outside the self-trapping region.
Accelerator testing of the general antiparticle spectrometer; a novel approach to indirect dark matter detection
2005
We report on recent accelerator testing of a prototype general antiparticle spectrometer (GAPS). GAPS is a novel approach for indirect dark matter searches that exploits the antideuterons produced in neutralino-neutralino annihilations. GAPS captures these antideuterons into a target with the subsequent formation of exotic atoms. These exotic atoms decay with the emission of X-rays of precisely defined energy and a correlated pion signature from nuclear annihilation. This signature uniquely characterizes the antideuterons. Preliminary analysis of data from a prototype GAPS in an antiproton beam at the KEK accelerator in Japan has confirmed the multi-X-ray/pion star topology and indicated X-…
New determination of the electron's mass.
2001
A new independent value for the electron's mass in units of the atomic mass unit is presented, ${m}_{e}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.0005485799092(4)\mathrm{u}$. The value is obtained from our recent measurement of the $g$ factor of the electron in ${}^{12}{\mathrm{C}}^{5+}$ in combination with the most recent quantum electrodynamical (QED) predictions. In the QED corrections, terms of order ${\ensuremath{\alpha}}^{2}$ were included by a perturbation expansion in $Z\ensuremath{\alpha}$. Our total precision is three times better than that of the accepted value for the electron's mass.
ATRAP antihydrogen experiments
2007
Antihydrogen (Hbar) was first produced at CERN in 1996. Over the past decade our ATRAP collaboration has made massive progress toward our goal of producing large numbers of cold Hbar atoms that will be captured in a magnetic gradient trap for precise comparison between the atomic spectra of matter and antimatter. The AD at CERN provides bunches of 3 × 107 low energy Pbars every 100 seconds. We capture and cool to 4 K, 0.1% of these in a cryogenic Penning trap. By stacking many bunches we are able to do experiments with 3 × 105 Pbars. ∼100 e+/sec from a 22Na radioactive source are captured and cooled in the trap, with 5 × 106 available experiments.We have developed 2 ways to make Hbar from t…
Centrifugal Separation of Antiprotons and Electrons
2010
Centrifugal separation of antiprotons and electrons is observed, the first such demonstration with particles that cannot be laser cooled or optically imaged. The spatial separation takes place during the electron cooling of trapped antiprotons, the only method available to produce cryogenic antiprotons for precision tests of fundamental symmetries and for cold antihydrogen studies. The centrifugal separation suggests a new approach for isolating low energy antiprotons and for producing a controlled mixture of antiprotons and electrons.
First Capture of Antiprotons in a Penning Trap: A Kiloelectronvolt Source
1986
Antiprotons from the Low Energy Antiproton Ring of CERN are slowed from 21 MeV to below 3 keV by being passed through 3 mm of material, mostly Be. While still in flight, the kiloelectronvolt antiprotons are captured in a Penning trap created by the sudden application of a 3-kV potential. Antiprotons are held for 100 s and more. Prospects are now excellent for much longer trapping times under better vacuum conditions. This demonstrates the feasibility of a greatly improved measurement of the inertial mass of the antiproton and opens the way to other intriguing experiments.