2,684 research outputs found
TOTEM: The experiment to measure the total proton-proton cross section at LHC
The current large uncertainty on the extrapolation of the proton-proton total
cross section at the LHC energy will be resolved by the precise measurement by
the TOTEM experiment. Its accurate studies on the basic properties of
proton-proton collisions at the maximum accelerator energy could provide a
significant contribution to the understanding of cosmic ray physics.Comment: 6 pages, 7 figures, Proceedings XIV International Symposium on Very
High Energy Cosmic Ray Interactions (ISVHECRI 2006), Weihai, China, August
15-22, 200
A triple-GEM telescope for the TOTEM experiment
The TOTEM experiment at LHC has chosen the triple Gas Electron Multiplier
(GEM) technology for its T2 telescope which will provide charged track
reconstruction in the rapidity range 5.3<|eta|<6.5 and a fully inclusive
trigger for diffractive events. GEMs are gas-filled detectors that have the
advantageous decoupling of the charge amplification structure from the charge
collection and readout structure. Furthermore, they combine good spatial
resolution with very high rate capability and a good resistance to radiation.
Results from a detailed T2 GEM simulation and from laboratory tests on a final
design detector performed at CERN are presented.Comment: To appear in the proceedings of 10th Topical Seminar on Innovative
Particle and Radiation Detectors (IPRD06), Siena, Italy, October 1-5 200
semileptonic form factors with Twisted Mass fermions
We present a lattice QCD determination of the vector and scalar form factors
of the semileptonic decay which are relevant for the
extraction of the CKM matrix element from experimental data. Our
results are based on the gauge configurations produced by the European Twisted
Mass Collaboration with dynamical fermions, which include in the
sea, besides two light mass degenerate quarks, also the strange and the charm
quarks. We use data simulated at three different values of the lattice spacing
and with pion masses as small as MeV. Our final result for the vector
form factor at zero momentum transfer is , where the
uncertainty is both statistical and systematic combined in quadrature. Using
the latest experimental value of from decays, we
obtain , which allows to test the unitarity constraint
of the Standard Model below the permille level once the determination of
from superallowed nuclear decays is adopted. A slight
tension with unitarity at the level of standard deviations is
observed. Moreover we present our results for the semileptonic scalar
and vector form factors in the whole range of values of
the squared four-momentum transfer measured in decays,
obtaining a very good agreement with the momentum dependence of the
experimental data. We provide a set of synthetic data points representing our
results for the vector and scalar form factors at the physical point for
several selected values of .Comment: 37 pages, 5 tables, 9 figures; version to appear in PR
The CDF MiniPlug Calorimeters at the Tevatron
Two MiniPlug calorimeters, designed to measure the energy and lateral
position of particles in the pseudorapidity region of 3.6<|eta|<5.1 of the CDF
detector, have been installed as part of the Run II CDF upgrade at the Tevatron
collider. Detector performance and first results from collision data
are presented.Comment: Presented at `Frontier Detectors for Frontier Physics; 9th Pisa
Meeting on Advanced Detectors', Biodola, Italy, 25-31 May 2003. 2 page
New Limited Molecular Weight Polymeric Dispersants Prepared by Melt Condensation Polymerization
In this work, poly(sebacic anhydride) was prepared in a new method of condensation polymerization of sebacic acid monomer and sebacoyl chloride monomer in presence of triethyl amine, this polymer was purified, characterized by infrared spectroscopy. Poly(sebacic anhydride) was used to prepare poly(ethylene glycol)-sebacic acid copolymers with carboxylic end groups and limited molecular weight using poly(ethylene glycol) having different chain length (400, 2000, 10000 and 20000 g/mole) by melt condensation polymerization. The copolymers were purified, characterized by infrared spectroscopy and end-group analysis of molecular weight determination technique. These polymers were tested as dispersants for ceramic alumina particles in ethanol as dispersion medium using centrifugation settlement method; High packing densities for alumina particles were obtained. It was found that the packing densities of alumina particles have been influenced by the polymer concentration and poly) ethylene glycol) chain length. Their adsorption isotherms were also determined, it was found that the adsorption is molecular weight dependent and linear relationship was obtained between the maximum adsorption of the polymers and their molecular weights. Keywords: melt condensation, poly(sebacic anhydride), poly(ethylene glycol)-sebacic acid, alumina, dispersants, isotherm adsorptio
Biodegradation Studies in Vitro of Novel Poly(adipic anhydride-co-mannitol)-N-maleoyl Chitosan Networks
In this work, novel copolymers of poly(adipic anhydride-co-mannitol) were synthesized by melting condensation polymerization of poly(adipic anhydride) with five percentages of mannitol sugar, 1 to 5 Wt.%. These copolymers were purified and then, characterized by FT-IR, which was proved that the cross-linking reaction was caused by nucleophilic attack of mannitol hydroxyl group to acidic anhydride groups of poly(adipic anhydride) backbone and new ester groups were formed and appeared. Also, modified organic-soluble chitosan, N-maleoyl-chitosan, were synthesized by grafting reaction of chitosan with maleic anhydride in DMF as solvent, and it was also purified and characterized by FT-IR. Biodegradation in vitro of the IPNs of poly(adipic anhydride-co-mannitol)-N-maleoyl chitosan networks were evaluated by hydrolytic degradation studies at three different media (PBS, SIF and SGF) for 18 weeks with 92% as maximum degradation and it was found that minimum weight loss of IPNs was noticeably shown in SIF. In addition, hydrolytic degradation percent was decreased with increasing mannitol proportions
Penentuan Prioritas pada Jaringan Back-bone Palapa Ring Menggunakan Derajat Node dan Cut Vertex
Palapa Ring is a project aiming to connect provinces and cities in Indonesia via a high data speed telecommunication path. The purpose of this research is to identify the priority scale of each node in Palapa Ring Backbone network by considering the degree of each node and the cut vertices of the network. The result shows that the existing infrastructure in Palapa Ring comprised 48 nodes and 117 links. The nodes with the highest degree in the network were PBR, PTK, BJM, JK, SB and UP, with each of the nodes was connected to four links. Cut vertices in the network consisted of 22 nodes. The nodes in the network are classified into 4 categories. Five nodes (PBR, PTK, BJM, SB and UP) fell into the 1st priority group, two nodes (JK,MDN) fell into the 2nd priority group, 16 nodes fell into the 3rd priority group and the rest fell into the non priority group
- …