| Records |
| Author |
HADES Collaboration (Agakishiev, G. et al); Diaz, J.; Gil, A. |
| Title |
Origin of the low-mass electron pair excess in light nucleus-nucleus collisions |
Type |
Journal Article |
| Year |
2010 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
690 |
Issue |
2 |
Pages |
118-122 |
| Keywords |
Virtual bremsstrahlung; Dileptons; Nucleon-nucleon collisions |
| Abstract |
We report measurements of electron pair production in elementary p + p and d + p reactions at 1.25 GeV/mu with the HADES spectrometer. For the first time, the electron pairs were reconstructed for n + p reactions by detecting the proton spectator from the deuteron breakup. We find that the yield of electron pairs with invariant mass Me+e- > 0.15 GeV/c(2) is about an order of magnitude larger in n + p reactions as compared to p + p. A comparison to model calculations demonstrates that the production mechanism is not sufficiently described yet. The electron pair spectra measured in C + C reactions are compatible with a superposition of elementary n + p and p + p collisions, leaving little room for additional electron pair sources in such light collision systems. |
| Address |
[Froehlich, I.; Galatyuk, T.; Goebel, K.; Lorenz, M.; Markert, J.; Michel, J.; Muentz, C.; Pachmayer, Y. C.; Stroebele, H.; Stroth, J.; Sturm, C.; Tarantola, A.; Teilab, K.] Goethe Univ Frankfurt, Inst Kernphys, D-60438 Frankfurt, Germany, Email: t.galatyuk@gsi.de |
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| Publisher |
Elsevier Science Bv |
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| Language |
English |
Summary Language |
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Series Issue |
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Edition |
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| ISSN |
0370-2693 |
ISBN |
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Expedition |
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Conference |
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Notes  |
ISI:000279513800003 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ elepoucu @ |
Serial |
413 |
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| Author |
Mendez, V.; Amoros, G.; Garcia, F.; Salt, J. |
| Title |
Emergent algorithms for replica location and selection in data grid |
Type |
Journal Article |
| Year |
2010 |
Publication |
Future Generation Computer Systems |
Abbreviated Journal |
Futur. Gener. Comp. Syst. |
| Volume |
26 |
Issue |
7 |
Pages |
934-946 |
| Keywords |
Grid computing; Algorithms; Optimization methods; Artificial intelligence |
| Abstract |
Grid infrastructures for e-Science projects are growing in magnitude terms. Improvements in data Grid replication algorithms may be critical in many of these infrastructures. This paper shows a decentralized replica optimization service, providing a general Emergent Artificial Intelligence (EAI) algorithm for the problem definition. Our aim is to set up a theoretical framework for emergent heuristics in Grid environments. Further, we describe two EAI approaches, the Particle Swarm Optimization PSO-Grid Multiswarm Federation and the Ant Colony Optimization ACO-Grid Asynchronous Colonies Optimization replica optimization algorithms, with some examples. We also present extended results with best performance and scalability features for PSO-Grid Multiswarrn Federation. |
| Address |
[Mendez Munoz, Victor; Amoros Vicente, Gabriel; Salt Cairols, Jose] CSIC, Grid & E Sci Grp, Inst Fis Corpuscular IFIC, Mixed Inst, E-46071 Valencia, Spain, Email: vmendez@ific.uv.es |
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Thesis |
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| Publisher |
Elsevier Science Bv |
Place of Publication |
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| Language |
English |
Summary Language |
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Series Title |
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Series Issue |
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Edition |
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| ISSN |
0167-739x |
ISBN |
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Expedition |
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Conference |
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| Notes |
ISI:000279804200004 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ elepoucu @ |
Serial |
411 |
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| Author |
Garcia-Recio, C.; Nieves, J.; Tolos, L. |
| Title |
D mesic nuclei |
Type |
Journal Article |
| Year |
2010 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
690 |
Issue |
4 |
Pages |
369-375 |
| Keywords |
Charm; Mesic nuclei; Heavy quark symmetry |
| Abstract |
The energies and widths of several D-0 meson bound states for different nuclei are obtained using a D-meson selfenergy in the nuclear medium, which is evaluated in a selfconsistent manner using techniques of unitarized coupled-channel theory. The kernel of the meson-baryon interaction is based on a model that treats heavy pseudoscalar and heavy vector mesons on equal footing, as required by heavy quark symmetry. We find D-0 bound states in all studied nuclei, from C-12 up to Pb-208. The inclusion of vector mesons is the keystone for obtaining an attractive D-nucleus interaction that leads to the existence of D-0-nucleus bound states, as compared to previous studies based on SU(4) flavor symmetry. In some cases, the half widths are smaller than the separation of the levels, what makes possible their experimental observation by means of a nuclear reaction. This can be of particular interest for the future PANDA@FAIR physics program. We also find a D+ bound state in C-12, but it is too broad and will have a significant overlap with the energies of the continuum. |
| Address |
[Garcia-Recio, C.] Univ Granada, Dept Fis Atom Mol & Nucl, E-18071 Granada, Spain, Email: g_recio@ugr.es |
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| Publisher |
Elsevier Science Bv |
Place of Publication |
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| Language |
English |
Summary Language |
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Edition |
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| ISSN |
0370-2693 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
ISI:000279835300007 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ elepoucu @ |
Serial |
407 |
| Permanent link to this record |
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| Author |
Yamagata-Sekihara, J.; Oset, E. |
| Title |
V P gamma radiative decay of resonances dynamically generated from the vector meson-vector meson interaction |
Type |
Journal Article |
| Year |
2010 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
690 |
Issue |
4 |
Pages |
376-381 |
| Keywords |
Local hidden gauge; Radiative decays; Vector mesons; Dynamically generated resonances |
| Abstract |
We evaluate the radiative decay into a vector, a pseudoscalar and a photon of several resonances dynamically generated from the vector-vector interaction. The process proceeds via the decay of one of the vector components into a pseudoscalar and a photon, which have an invariant mass distribution very different from phase space as a consequence of the two vector structure of the resonances. Experimental work along these lines should provide useful information on the nature of these resonances. |
| Address |
[Yamagata-Sekihara, J.] Univ Valencia, Ctr Mixto, CSIC, Inst Invest Paterna,Dept Fis Teor, Valencia 46071, Spain, Email: yamagata@ific.uv.es |
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Thesis |
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| Publisher |
Elsevier Science Bv |
Place of Publication |
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| Language |
English |
Summary Language |
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| ISSN |
0370-2693 |
ISBN |
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Expedition |
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Conference |
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| Notes |
ISI:000279835300008 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ elepoucu @ |
Serial |
408 |
| Permanent link to this record |
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| Author |
CDF Collaboration (Aaltonen, T. et al); Cabrera, S. |
| Title |
Search for new color-octet vector particle decaying to t(t)over-bar in p(p)over-bar collisions at root s=1.96 TeV |
Type |
Journal Article |
| Year |
2010 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
691 |
Issue |
4 |
Pages |
183-190 |
| Keywords |
Massive gluon; Top quark |
| Abstract |
We present the result of a search for a massive color-octet vector particle, (e.g. a massive gluon) decaying to a pair of top quarks in proton-antiproton collisions with a center-of-mass energy of 1.96 TeV. This search is based on 1.9 fb(-1) of data collected using the CDF detector during Run II of the Tevatron at Fermilab. We study t (t) over bar events in the lepton + jets channel with at least one b-tagged jet. A massive gluon is characterized by its mass, decay width, and the strength of its coupling to quarks. These parameters are determined according to the observed invariant mass distribution of top quark pairs. We set limits on the massive gluon coupling strength for masses between 400 and 800 GeV/c(2) and width-to-mass ratios between 0.05 and 0.50. The coupling strength of the hypothetical massive gluon to quarks is consistent with zero within the explored parameter space. |
| Address |
[Nara, K.; Kim, S. H.; Kurata, M.; Miyake, H.; Nagai, Y.; Naganoma, J.; Nakamura, K.; Sato, K.; Shimojima, M.; Takeuchi, Y.; Tomura, T.; Ukegawa, F.] Univ Tsukuba, Tsukuba, Ibaraki 305, Japan, Email: junji@fnal.gov |
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Thesis |
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| Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0370-2693 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
ISI:000280328200002 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
278 |
| Permanent link to this record |
