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Author |
Noguera, S.; Vento, V. |
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Title |
The pion transition form factor and the pion distribution amplitude |
Type |
Journal Article |
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Year |
2010 |
Publication |
European Physical Journal A |
Abbreviated Journal |
Eur. Phys. J. A |
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Volume |
46 |
Issue |
2 |
Pages |
197-205 |
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Abstract  |
Recent BaBar data on the pion transition form factor, whose Q(2)-dependence is much steeper then predicted by asymptotic Quantum Chromodynamics (QCD), have caused a renewed interest in its theoretical description. We present here a formalism based on a model-independent description for low photon virtuality and a high photon virtuality description based on QCD, which match at a scale Q(0). The high photon virtuality description incorporates a flat pion distribution amplitude, phi(x) = 1, at the matching scale Q(0) and QCD evolution from Q(0) to Q > Q(0). The flat pion distribution is connected, through soft pion theorems and chiral symmetry, to the pion valence parton distribution at the same low scale Q(0). The procedure leads to a good description of the data, and by incorporating additional twist-three effects, to an excellent description of the data. |
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Address |
[Noguera, S.] Univ Valencia, Dept Fis Teor, CSIC, E-46100 Valencia, Spain, Email: Santiago.Noguera@uv.es |
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Publisher |
Springer |
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Language |
English |
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Series Volume |
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ISSN |
1434-6001 |
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Conference |
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Notes |
ISI:000284869600005 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ elepoucu @ |
Serial |
312 |
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Author |
HADES Collaboration (Agakishiev, G. et al); Diaz, J.; Gil, A. |
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Title |
Lambda-p femtoscopy in collisions of Ar + KCl at 1.76AGeV |
Type |
Journal Article |
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Year |
2010 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
82 |
Issue |
2 |
Pages |
021901 - 5pp |
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Keywords |
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Abstract |
Results on Lambda p femtoscopy are reported at the lowest energy so far. At a beam energy of 1.76AGeV, the reaction Ar + KCl was studied with the High Acceptance Di-Electron Spectrometer ( HADES) at SIS18/GSI. A high-statistics and high-purity Lambda sample was collected, allowing for the investigation of Lambda p correlations at low relative momenta. The experimental correlation function is compared to corresponding model calculations allowing the determination of the space-time extent of the Lambda p emission source. The Lambda p source radius is found to be slightly smaller than the pp correlation radius for a similar collision system. The present Lambda p radius is significantly smaller than that found for Au + Au/Pb + Pb collisions in the AGS, SPS, and RHIC energy domains but larger than that observed for electroproduction from He. Taking into account all available data, we find the Lambda p source radius to increase almost linearly with the number of participants to the power of one-third. |
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Address |
[Finocchiaro, P.] Ist Nazl Fis Nucl, Lab Nazl Sud, I-95125 Catania, Italy, Email: kotte@fzd.de |
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Corporate Author |
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Publisher |
Amer Physical Soc |
Place of Publication |
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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 |
0556-2813 |
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Conference |
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Notes |
ISI:000281017300001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
393 |
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Author |
BABAR Collaboration (Aubert, B. et al); Azzolini, V.; Lopez-March, N.; Martinez-Vidal, F.; Milanes, D.A.; Oyanguren, A. |
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Title |
Searches for Lepton Flavor Violation in the Decays tau(+/-) -> e(+/-)gamma and tau(+/-) -> mu(+/-)gamma |
Type |
Journal Article |
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Year |
2010 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
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Volume |
104 |
Issue |
2 |
Pages |
021802 - 7pp |
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Keywords |
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Abstract |
Searches for lepton-flavor-violating decays of a tau lepton to a lighter mass lepton and a photon have been performed with the entire data set of (963 +/- 7) x 10(6) tau decays collected by the BABAR detector near the Y(4S), Y(3S) and Y(2S) resonances. The searches yield no evidence of signals and we set upper limits on the branching fractions of B(tau(+/-) -> e(+/-)gamma) < 3.3 X 10(-8) and B(tau(+/-) -> mu(+/-)gamma) < 4.4 X 10(-8) at 90% confidence level. |
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Address |
[Aubert, B.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.] Univ Savoie, CNRS, IN2P3, Lab Annecy le Vieux Phys Particules, F-74941 Annecy Le Vieux, France |
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Corporate Author |
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Publisher |
Amer Physical Soc |
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 |
0031-9007 |
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:000274002900013 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
508 |
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Author |
Carlson, E.D.; Anderson, P.R.; Fabbri, A.; Fagnocchi, S.; Hirsch, W.H.; Klyap, S.A. |
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Title |
Semiclassical gravity in the far field limit of stars, black holes, and wormholes |
Type |
Journal Article |
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Year |
2010 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
82 |
Issue |
12 |
Pages |
124070 - 24pp |
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Keywords |
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Abstract |
Semiclassical gravity is investigated in a large class of asymptotically flat, static, spherically symmetric spacetimes including those containing static stars, black holes, and wormholes. Specifically the stress-energy tensors of massless free spin 0 and spin 1/2 fields are computed to leading order in the asymptotic regions of these spacetimes. This is done for spin 0 fields in Schwarzschild spacetime using a WKB approximation. It is done numerically for the spin 1/2 field in Schwarzschild, extreme Reissner-Nordstrom, and various wormhole spacetimes. And it is done by finding analytic solutions to the leading order mode equations in a large class of asymptotically flat static spherically symmetric spacetimes. Agreement is shown between these various computational methods. It is found that, for all of the spacetimes considered, the energy density and pressure in the asymptotic region are proportional to r(-5) to leading order. Furthermore, for the spin 1/2 field and the conformally coupled scalar field, the stress-energy tensor depends only on the leading order geometry in the far field limit. This is also true for the minimally coupled scalar field for spacetimes containing either a static star or a black hole, but not for spacetimes containing a wormhole. |
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Address |
[Carlson, Eric D.; Anderson, Paul R.; Hirsch, William H.; Klyap, Sarah A.] Wake Forest Univ, Dept Phys, Winston Salem, NC 27109 USA, Email: ecarlson@wfu.edu |
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Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
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 |
1550-7998 |
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:000286749400008 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
531 |
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Author |
Deo, A.Y.; Podolyak, Z.; Walker, P.M.; Algora, A.; Rubio, B.; Agramunt, J.; Fraile, L.M.; Al-Dahan, N.; Alkhomashi, N.; Briz, J.A.; Estevez, E.; Farrelly, G.; Gelletly, W.; Herlert, A.; Koster, U.; Maira, A.; Singla, S. |
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Title |
Structures of Po-201 and Rn-205 from EC/beta(+)-decay studies |
Type |
Journal Article |
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Year |
2010 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
81 |
Issue |
2 |
Pages |
024322 - 8pp |
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Keywords |
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Abstract |
Several low-lying excited states in Rn-205(86)119 and Po-201(84)117 were identified for the first time following EC/beta(+) decay of Fr-205 and At-201, respectively, using gamma-ray and conversion electron spectroscopy at the CERN isotope separator on-line (ISOLDE) facility. The EC/beta(+) branch from Fr-205 was measured to be 1.5(2)%. The excited states of the daughter nuclei are understood in terms of the odd nucleon coupling to the neighboring even-even core. The neutron single-particle energies of the p(3/2) orbital relative to the f(5/2) ground state in Rn-205, and the f(5/2) orbital relative to the p(3/2) ground state in Po-201, were determined to be 31.4(2) and 5.7(3) keV, respectively. We tentatively identify a 13/2(+) isomeric level at 657.1(5) keV in Rn-205. The systematic behavior of the 13/2(+) and 3/2(-) levels is also discussed. |
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Address |
[Deo, A. Y.; Podolyak, Zs.; Walker, P. M.; Al-Dahan, N.; Alkhomashi, N.; Farrelly, G.; Gelletly, W.] Univ Surrey, Dept Phys, Guildford GU2 7XH, Surrey, England, Email: A.Deo@surrey.ac.uk |
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Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
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 |
0556-2813 |
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:000278341300001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
431 |
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| Permanent link to this record |
