A J P L Policarpo

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We use ts to recent published CPLEAR data on neutral kaon decays to + and e to constrain the CPT{violation parameters appearing in a formulation of the neutral kaon system as an open quantum-mechanical system. The obtained upper limits of the CPT{violation parameters are approaching the range suggested by certain ideas concerning quantum gravity.
The151Sm(n,gamma)152Sm cross section has been measured at the spallation neutron facility n_TOF at CERN in the energy range from 1 eV to 1 MeV. The new facility combines excellent resolution in neutron time-of-flight, low repetition rates, and an unsurpassed instantaneous luminosity, resulting in rather favorable signal/background ratios. The 151Sm cross(More)
A large-area Resistive Plate Chamber (RPC) with a total active surface of 160×10 cm was built and tested. The surface was segmented into two 5-cm wide strips readout on both ends with customized, very high speed, front-end electronics. A timing resolution σ = 50-75 ps, with an efficiency for Minimum Ionizing Particles (MIPs) larger than 95%, was attained(More)
In this work, we report the development and performance of single-gap timing RPCs equipped with a 3mm FWHM resolution bidimensional position-sensitive readout and reaching a timing resolution of 55 ps s at an efficiency of 75% for MIPs. These chambers are aimed to be applied in a multilayer geometry, forming small and very accurate TOF systems. The(More)
An imaging detector with good energy resolution and reasonable spatial accuracy has been designed for biomedical applications. It is based on a scintillating proportional gas chamber. The energy resolution is typically 5.4% (FWHM) at 27 keV and the spatial resolution is 2.7 mm (FWHM) for 22-keV x-rays. The physical processes involved in this detector are(More)
For many applications of RPCs to time-of-flight counters in heavy ion experiments the expansion to much higher values of the counting rate capability, so far limited to around 2 kHz/cm is of fundamental importance. To address this issue we developed single-gap timing RPCs with resistive electrodes made from a commercially available plastic material. Tests(More)
  • Bergen, Norway, +260 authors Kiš
  • 2004
The CBM Collaboration proposes to build a dedicated heavy-ion experiment to investigate the properties of highly compressed baryonic matter as it is produced in nucleus-nucleus collisions at the future accelerator facility in Darmstadt. Our goal is to explore the QCD phase diagram in the region of moderate temperatures but very high baryon densities. The(More)
R. Adler a, T. Alhalel b A. Angelopoulos c, A. Apostolakis c, E. Aslanides d,b G. Backenstoss a, C.P. Bee d,e, j. Bennet e, J.K. Bienlein f, P. Bloch d, Ch. Bula g, G. Burgun h, p. Carlson i, J. Carvalho J, E. Cawley e, S. Charalambous k, M. Chardalas k, G. Chardin h, H. Cobbaert J, S. Dedoussis k, M. Dejardin h, j. Derre h, M. Dodgson e, J.C. Dousse ~, J.(More)
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