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Author |
Kochelev, N.I.; Vento, V. |
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Title |
Gluonic components of the pion and the transition form factor gamma*gamma* -> pi(0) |
Type |
Journal Article |
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Year |
2010 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume  |
81 |
Issue |
3 |
Pages |
034009 - 5pp |
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Keywords |
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Abstract |
We propose an effective Lagrangian for the coupling of the neutral pion with gluons whose strength is determined by a low-energy theorem. We calculate the contribution of the gluonic components arising from this interaction to the pion transition form factor gamma*gamma* -> pi(0) using the instanton liquid model to describe the quantum chromodynamics vacuum. We find that this contribution is large and might explain the anomalous behavior of the form factor at large virtuality of one of the photons, a feature which was recently discovered by the BABAR Collaboration. |
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Address |
[Kochelev, N. I.] Joint Inst Nucl Res, Bogoliubov Lab Theoret Phys, Dubna 141980, Moscow Region, Russia, Email: kochelev@theor.jinr.ru |
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Amer Physical Soc |
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English |
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ISSN |
1550-7998 |
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ISI:000275069000030 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
495 |
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Author |
Gomez Dumm, D.; Roig, P.; Pich, A.; Portoles, J. |
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Title |
Hadron structure in tau -> KK pi nu(tau) decays |
Type |
Journal Article |
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Year |
2010 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
81 |
Issue |
3 |
Pages |
034031 - 17pp |
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Keywords |
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Abstract |
We analyze the hadronization structure of both vector and axial-vector currents leading to tau -> KK pi nu(tau) decays. At leading order in the 1/N-C expansion, and considering only the contribution of the lightest resonances, we work out, within the framework of the resonance chiral Lagrangian, the structure of the local vertices involved in those processes. The couplings in the resonance theory are constrained by imposing the asymptotic behavior of vector and axial-vector spectral functions ruled by QCD. In this way we predict the hadron spectra and conclude that, contrary to previous assertions, the vector contribution dominates by far over the axial-vector one in all KK pi charge channels. |
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Address |
[Gomez Dumm, D.] Univ Nacl La Plata, IFLP, CONICET, Dpto Fis, RA-1900 La Plata, Argentina |
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Amer Physical Soc |
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English |
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ISSN |
1550-7998 |
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Expedition |
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Conference |
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Notes |
ISI:000275069000052 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
496 |
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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 |
Observation of inclusive D*(+/-) production in the decay of Y(1S) |
Type |
Journal Article |
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Year |
2010 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
81 |
Issue |
1 |
Pages |
011102 - 8pp |
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Keywords |
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Abstract |
We present a study of the inclusive D*(+/-) production in the decay of Y(1S) using (98.6 +/- 0.9) X 10(6) Y(2S) mesons collected with the BABAR detector at the Y(2S) resonance. Using the decay chain Y(2S) -> pi(+)pi Y-(1S), Y(1S) -> D*X-+/-, where X is unobserved, we measure the branching fraction B[Y(1S) -> D*X-+/-] = (2.52 +/- 0.13(stat) +/- 0.15(syst)% and the D*(+/-) momentum distribution in the rest frame of the Y(1S). We find evidence for an excess of D*+/- production over the expected rate from the virtual photon annihilation process Y(1S) -> gamma* -> c (c) over bar -> D*X-+/-. |
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Address |
[Aubert, B.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Sanchez, P. del Amo; Ben-Haim, E.; Bonneaud, G. R.; Briand, H.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Perez, A.; Prendki, J.; Sitt, S.] Univ Savoie, CNRS, IN2P3, LAPP, F-74941 Annecy Le Vieux, France |
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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 |
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:000274002800002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
502 |
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Author |
Roca, L.; Oset, E. |
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Title |
Asymmetry observables in e(+)e(-) -> pi(+) pi(-) gamma in the phi region within a chiral unitary approach |
Type |
Journal Article |
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Year |
2010 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
81 |
Issue |
1 |
Pages |
014010 - 8pp |
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Keywords |
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Abstract |
We make a theoretical study of the charge and forward-backward pion asymmetries in the e(+)e(-) -> pi(+) pi(-) gamma process on and off the phi resonance energy. These observables are rather sensitive to the inner details of the theoretical models to describe the reaction. In addition to the standard implementation of the initial state radiation and the bremsstrahlung contribution to the final state radiation, we use the techniques of the chiral unitary approach to evaluate the contribution from the mechanisms of phi decay into pi(+) pi(-) gamma. This contribution involves the implementation of final state interaction from direct chiral loops, the exchange of vector and axial-vector resonances and the final state interaction through the consideration of the meson-meson unitarized amplitudes, which were found important in a previous work describing the phi -> pi pi gamma. We find a good reproduction of the experimental data from KLOE for the forward-backward asymmetry, both at the phi peak and away from it. We also make predictions for the angular distributions of the charge asymmetry and show that this observable is very sensitive to the chiral loops involved in phi radiative decay. |
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Address |
[Roca, L.] Univ Murcia, Dept Fis, E-30071 Murcia, Spain |
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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 |
1550-7998 |
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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:000274002800021 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ elepoucu @ |
Serial |
503 |
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Author |
Rafi Alam, M.; Ruiz Simo, I.; Sajjad Athar, M.; Vicente Vacas, M.J. |
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Title |
Weak kaon production off the nucleon |
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 |
3 |
Pages |
033001 - 8pp |
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Keywords |
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Abstract |
The weak kaon production off the nucleon induced by neutrinos is studied at the low and intermediate energies of interest for some ongoing and future neutrino oscillation experiments. This process is also potentially important for the analysis of proton decay experiments. We develop a microscopical model based on the SU(3) chiral Lagrangians. The basic parameters of the model are f pi, the pion decay constant, Cabibbo's angle, the proton and neutron magnetic moments, and the axial vector coupling constants for the baryons octet, D and F, that are obtained from the analysis of the semileptonic decays of neutron and hyperons. The studied mechanisms are the main source of kaon production for neutrino energies up to 1.2 to 1.5 GeV for the various channels and the cross sections are large enough to be amenable to be measured by experiments such as Minerva and T2K. |
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Address |
[Alam, M. Rafi; Athar, M. Sajjad] Aligarh Muslim Univ, Dept Phys, Aligarh 202002, Uttar Pradesh, India |
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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:000280576800001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
397 |
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| Permanent link to this record |
