Records |
Author |
Guevara, A.; Lopez Castro, G.; Roig, P. |
Title |
Improved description of dilepton production in tau(-) -> nu(tau)P(- )decays |
Type |
Journal Article |
Year |
2022 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
105 |
Issue |
7 |
Pages |
076007 - 15pp |
Keywords |
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Abstract |
Recently, the Belle Collaboration reported the first measurements of the tau(-) -> nu(tau)pi(-) e(+) e(-) branching fraction and the spectrum of the pion-dielectron system. In an analysis previous to Belle's results, we evaluated this branching fraction which turned out to be compatible with that reported by Belle, although with a large uncertainty. This is the motivation to seek for improvement on our previous evaluation of tau(-) -> nu(tau)pi(-) l(+) l(-) decays (l = e, mu). In this paper we improve our calculation of the WP-gamma* vertex by including flavor-symmetry breaking effects in the framework of the resonance chiral theory. We impose QCD short-distance behavior to constrain most parameters and data on the pi(-) e(+) e(-) spectrum reported by the Belle Collaboration to fix the remaining free ones. As a result, improved predictions for the branching ratios and hadronic/leptonic spectra are reported, which are in good agreement with observations. Analogous calculations for the strangeness-changing tau(-) -> nu(tau) K- l(+) l(-) transitions are reported for the first time. Albeit one expects the m(pi mu+ mu- )spectrum to be measured in Belle-II and the observables with l = e can be improved, it is rather unlikely that the K channels can be measured due to the suppression factor vertical bar V-ud/V-us vertical bar(2) = 0.05. |
Address ![sorted by Address field, descending order (down)](img/sort_desc.gif) |
[Guevara, Adolfo] Univ Granada, Dept Fis Atom Mol & Nucl, E-18071 Granada, Spain |
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Thesis |
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Amer Physical Soc |
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Editor |
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English |
Summary Language |
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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 |
2470-0010 |
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 |
WOS:000789304200003 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
5212 |
Permanent link to this record |
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Author |
Guerrero, M.; Olmo, G.J.; Rubiera-Garcia, D.; Saez-Chillon Gomez, D. |
Title |
Multiring images of thin accretion disk of a regular naked compact object |
Type |
Journal Article |
Year |
2022 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
106 |
Issue |
4 |
Pages |
044070 - 13pp |
Keywords |
|
Abstract |
We discuss the importance of multiring images in the optical appearance of a horizonless spherically symmetric compact object, when illuminated by an optically thin accretion disk. Such an object corresponds to a subcase of an analytically tractable extension of the Kerr solution dubbed as the “eye of the storm” by Simpson and Visser in [J. Cosmol. Astropart. Phys. 03 (2022) 011], which merits in removing curvature singularities via an asymptotically Minkowski core, while harboring both a critical curve and an infinite potential barrier at the center for null geodesics. This multiring structure is induced by light rays winding several times around the object, and whose luminosity is significantly boosted as compared to the Schwarzschild solution by the modified shape of the potential. Using three toy profiles for the emission of an infinitely thin disk, truncated at its inner edge (taking its maximum value there) and having different decays with the distance, we discuss the image created by up to eight rings superimposed on top of the direct emission of the disk as its edge is moved closer to the center of the object. Our results point to the existence of multiring images with a non-negligible luminosity in shadow observations when one allows for the existence of other compact objects in the cosmic zoo beyond the Schwarzschild solution. Such multiring images could be detectable within the future projects on very long baseline interferometry. |
Address ![sorted by Address field, descending order (down)](img/sort_desc.gif) |
[Guerrero, Merce; Rubiera-Garcia, Diego] Univ Complutense Madrid, Dept Fis Teor, IPARCOS, Madrid 28040, Spain, Email: merguerr@ucm.es; |
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Amer Physical Soc |
Place of Publication |
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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 |
2470-0010 |
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 |
WOS:000850772800006 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
5352 |
Permanent link to this record |
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Author |
Guerrero, M.; Olmo, G.J.; Rubiera-Garcia, D.; Saez-Chillon Gomez, D. |
Title |
Light ring images of double photon spheres in black hole and wormhole spacetimes |
Type |
Journal Article |
Year |
2022 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
105 |
Issue |
8 |
Pages |
084057 - 16pp |
Keywords |
|
Abstract |
The silhouette of a black hole having a critical curve (an unstable bound photon orbit) when illuminated by an optically thin accretion disk whose emission is confined to the equatorial plane shows a distinctive central brightness depression (the shadow) whose outer edge consists of a series of strongly lensed, selfsimilar rings superimposed with the disk???s direct emission. While the size and shape of the critical curve depend only on the background geometry, the pattern of bright and dark regions (including the size and depth of the shadow itself) in the image is strongly influenced by the (astro)physics of the accretion disk. This aspect makes it difficult to extract clean and clear observational discriminators between the Kerr black hole and other compact objects. In the presence of a second critical curve, however, observational differences become apparent. In this work we shall consider some spherically symmetric black hole and wormhole geometries characterized by the presence of a second critical curve, via a uniparametric family of extensions of the Schwarzschild metric. By assuming three toy models of geometrically thin accretion disks, we show the presence of additional light rings in the intermediate region between the two critical curves. The observation of such rings could represent a compelling evidence for the existence of black hole mimickers having multiple critical curves. |
Address ![sorted by Address field, descending order (down)](img/sort_desc.gif) |
[Guerrero, Merce; Rubiera-Garcia, Diego] Univ Complutense Madrid, Dept Fis Teor, E-28040 Madrid, Spain, Email: merguerr@ucm.es; |
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Thesis |
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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 |
2470-0010 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
|
Notes |
WOS:000810908800018 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
5261 |
Permanent link to this record |
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Author |
Guerrero Navarro, G.H.; Vicente Vacas, M.J. |
Title |
Threshold pion electro- and photoproduction off nucleons in covariant chiral perturbation theory |
Type |
Journal Article |
Year |
2020 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
102 |
Issue |
11 |
Pages |
113016 - 23pp |
Keywords |
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Abstract |
Pion electro- and photoproduction off the nucleon close to threshold is studied in covariant baryon chiral perturbation theory at O(p(3)) in the extended-on-mass-shell scheme, with the explicit inclusion of the Delta(1232) resonance. The relevant low energy constants are fixed by fitting the available experimental data with the theoretical model. The inclusion of the Delta resonance as an explicit degree of freedom substantially improves the agreement with data and the convergence of the model. |
Address ![sorted by Address field, descending order (down)](img/sort_desc.gif) |
[Guerrero Navarro, Gustavo H.; Vicente Vacas, M. J.] Ctr Mixto UVEG CSIC, Dept Fis Teor, E-46071 Valencia, Spain, Email: gusguena@ific.uv.es; |
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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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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 |
2470-0010 |
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 |
WOS:000603547000001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
4670 |
Permanent link to this record |
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Author |
Guerrero Navarro, G.H.; Vicente Vacas, M.J.; Hiller Blin, A.N.; Yao, D.L. |
Title |
Pion photoproduction off nucleons in covariant chiral perturbation theory |
Type |
Journal Article |
Year |
2019 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
100 |
Issue |
9 |
Pages |
094021 - 18pp |
Keywords |
|
Abstract |
Pion photoproduction off the nucleon close to threshold is studied in covariant baryon chiral perturbation theory at O(p(3)) in the extended-on-mass-shell scheme, with the explicit inclusion of the Delta(1232) resonance using the delta counting. The theory is compared to the available data of cross sections and polarization observables for all the charge channels. Most of the necessary low-energy constants arc well known from the analysis of other processes and the comparison with data constrains some of the still unknown ones. The Delta(1232) contribution is significant in improving the agreement with data, even at the low energies considered. |
Address ![sorted by Address field, descending order (down)](img/sort_desc.gif) |
[Guerrero Navarro, Gustavo H.; Vacas, M. J. Vicente] UVEG, Ctr Mixto, CSIC, Dept Fis Teor, E-46071 Valencia, Spain, Email: gusguena@ific.uv.es; |
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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 |
2470-0010 |
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 |
WOS:000498060600002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4202 |
Permanent link to this record |
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Author |
Grieger, M.; Hensel, T.; Agramunt, J.; Bemmerer, D.; Degering, D.; Dillmann, I.; Fraile, L.M.; Jordan, D.; Koster, U.; Marta, M.; Muller, S.E.; Szucs, T.; Tain, J.L.; Zuber, K. |
Title |
Neutron flux and spectrum in the Dresden Felsenkeller underground facility studied by moderated He-3 counters |
Type |
Journal Article |
Year |
2020 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
101 |
Issue |
12 |
Pages |
123027 - 15pp |
Keywords |
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Abstract |
Ambient neutrons may cause significant background for underground experiments. Therefore, it is necessary to investigate their flux and energy spectrum in order to devise a proper shielding. Here, two sets of altogether ten moderated He-3 neutron counters are used for a detailed study of the ambient neutron background in tunnel IV of the Felsenkeller facility, underground below 45 m of rock in Dresden/Germany. One of the moderators is lined with lead and thus sensitive to neutrons of energies higher than 10 MeV. For each He-3 counter moderator assembly, the energy-dependent neutron sensitivity was calculated with the FLUKA code. The count rates of the ten detectors were then fitted with the MAXED and GRAVEL packages. As a result, both the neutron energy spectrum from 10(-9) to 300 MeV and the flux integrated over the same energy range were determined experimentally. The data show that at a given depth, both the flux and the spectrum vary significantly depending on local conditions. Energy-integrated fluxes of (0.61 +/- 0.05), (1.96 +/- 0.15), and (4.6 +/- 0.4) x 10(-4) cm(-2) s(-1), respectively, are measured for three sites within Felsenkeller tunnel IV which have similar muon flux but different shielding wall configurations. The integrated neutron flux data and the obtained spectra for the three sites are matched reasonably well by FLUKA Monte Carlo calculations that are based on the known muon flux and composition of the measurement room walls. |
Address ![sorted by Address field, descending order (down)](img/sort_desc.gif) |
[Grieger, M.; Hensel, T.; Bemmerer, D.; Mueller, S. E.; Szuecs, T.] Helmholtz Zentrum Dresden Rossendorf HZDR, D-01328 Dresden, Germany, Email: d.bemmerer@hzdr.de |
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 |
WOS:000542517900002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4442 |
Permanent link to this record |
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Author |
Gran, R.; Nieves, J.; Sanchez, F.; Vicente Vacas, M.J. |
Title |
Neutrino-nucleus quasi-elastic and 2p2h interactions up to 10 GeV |
Type |
Journal Article |
Year |
2013 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
88 |
Issue |
11 |
Pages |
113007 - 10pp |
Keywords |
|
Abstract |
We extend to 10 GeV results from a microscopic calculation of charged-current neutrino-nucleus reactions that do not produce a pion in the final state. For the class of events coming from neutrino interactions with two nucleons producing two holes (2p2h), limiting the calculation to three-momentum transfers less than 1.2 GeV produces a two-dimensional distribution in momentum and energy transfer that is roughly constant as a function of energy. The cross section for 2p2h interactions approximately scales with the number of nucleons for isoscalar nuclei, similar to the quasi-elastic cross section. When limited to momentum transfers below 1.2 GeV, the cross section is 26% of the quasi-elastic cross section at 3 GeV, but 14% if we neglect a Delta(1232) resonance absorption component. The same quantities are 33% and 17% for antineutrinos. For the quasi-elastic interactions, the full nuclear model with long range correlations produces an even larger, but approximately constant distortion of the shape of the four-momentum transfer at all energies above 2 GeV. The 2p2h enhancement and long-range correlation distortions to the cross section for these interactions are significant enough they should be observable in precision experiments to measure neutrino oscillations and neutrino interactions at these energies, but also balance out and produce less total distortion than each effect does individually. |
Address ![sorted by Address field, descending order (down)](img/sort_desc.gif) |
[Gran, R.] Univ Minnesota, Dept Phys, Duluth, MN 55812 USA |
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Amer Physical Soc |
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English |
Summary Language |
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Series Editor |
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Abbreviated Series Title |
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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 |
WOS:000328692000001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1666 |
Permanent link to this record |
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Author |
Gonzalez-Alonso, M.; Pich, A.; Rodriguez-Sanchez, A. |
Title |
Updated determination of chiral couplings and vacuum condensates from hadronic tau decay data |
Type |
Journal Article |
Year |
2016 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
94 |
Issue |
1 |
Pages |
014017 - 14pp |
Keywords |
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Abstract |
We analyze the lowest spectral moments of the left-right two-point correlation function, using all known short-distance constraints and the recently updated ALEPH V – A spectral function from tau decays. This information is used to determine the low-energy couplings L-10 and C-87 of chiral perturbation theory and the lowest-dimensional contributions to the operator product expansion of the left-right correlator. A detailed statistical analysis is implemented to assess the theoretical uncertainties, including violations of quark-hadron duality. |
Address ![sorted by Address field, descending order (down)](img/sort_desc.gif) |
[Gonzalez-Alonso, Martin] CNRS, IPN Lyon, F-69622 Villeurbanne, France |
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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 |
2470-0010 |
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 |
WOS:000379653200003 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2755 |
Permanent link to this record |
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Author |
Gonzalez-Alonso, M.; Pich, A.; Prades, J. |
Title |
Pinched weights and duality violation in QCD sum rules: A critical analysis |
Type |
Journal Article |
Year |
2010 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
82 |
Issue |
1 |
Pages |
014019 - 7pp |
Keywords |
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Abstract |
We analyze the so-called pinched weights, that are generally thought to reduce the violation of quarkhadron duality in finite-energy sum rules. After showing how this is not true in general, we explain how to address this question for the left-right correlator and any particular pinched weight, taking advantage of our previous work [1], where the possible high-energy behavior of the left-right spectral function was studied. In particular, we show that the use of pinched weights allows to determine with high accuracy the dimension six and eight contributions in the operator-product expansion, O-6 = (-4.3(-0.7)(+0.9)) x 10(-3) GeV6 and O-8 = (-7.2(-5.3)(+4.2)) x 10(-3) GeV8. |
Address ![sorted by Address field, descending order (down)](img/sort_desc.gif) |
[Gonzalez-Alonso, Martin; Pich, Antonio] Univ Valencia, CSIC, Dept Fis Teor, E-46071 Valencia, Spain |
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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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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:000280470200001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ elepoucu @ |
Serial |
403 |
Permanent link to this record |
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Author |
Gonzalez-Alonso, M.; Pich, A.; Prades, J. |
Title |
Violation of quark-hadron duality and spectral chiral moments in QCD |
Type |
Journal Article |
Year |
2010 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
81 |
Issue |
7 |
Pages |
074007 - 10pp |
Keywords |
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Abstract |
We analyze the spectral moments of the V – A two-point correlation function. Using all known short-distance constraints and the most recent experimental data from tau decays, we determine the lowest spectral moments, trying to assess the uncertainties associated with the so-called violations of quark-hadron duality. We have generated a large number of acceptable spectral functions, satisfying all conditions, and have used them to extract the wanted hadronic parameters through a careful statistical analysis. We obtain accurate values for the chi PT couplings L-10 and C-87, and a realistic determination of the dimension six and eight contributions in the operator product expansion, O-6 = (-5.4(-1.6)(+3.6)) . 10(-3) GeV6 and O-8 = d(-8.9-(12.6)(7.4+)) 10(-3) GeV8, showing that the duality-violation effects have been underestimated in previous literature. |
Address ![sorted by Address field, descending order (down)](img/sort_desc.gif) |
[Gonzalez-Alonso, Martin; Pich, Antonio] Univ Valencia, CSIC, Dept Fis Teor, E-46071 Valencia, Spain |
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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:000277201900025 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ elepoucu @ |
Serial |
459 |
Permanent link to this record |