| Records |
| Author |
Sekihara, T.; Martinez Torres, A.; Jido, D.; Oset, E. |
| Title |
Theoretical study of incoherent phi photoproduction on a deuteron target |
Type |
Journal Article |
| Year |
2012 |
Publication |
European Physical Journal A |
Abbreviated Journal |
Eur. Phys. J. A |
| Volume |
48 |
Issue |
1 |
Pages |
10 - 17pp |
| Keywords |
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| Abstract |
We study the photoproduction of phi mesons in deuteron, paying attention to the modification of the cross-section from bound protons to the free ones. For this purpose we take into account Fermi motion in single scattering and rescattering of phi to account for phi absorption on a second nucleon as well as the rescattering of the proton on the neutron. We find that the contribution of the double scattering for phi is much smaller than the typical cross-section of gamma p -> phi p in free space, which implies a very small screening of the phi production in deuteron. The contribution from the proton rescattering, on the other hand, is found to be not negligible compared to the cross-section of gamma p -> phi p in free space, and leads to a moderate reduction of the phi photoproduction cross-section on a deuteron at forward angles if the LEPS set-up is taken into account. The Fermi motion allows contribution of the single scattering in regions forbidden by phase-space in the free case. In particular, we find that for momentum transfer squared close to the maximum value, the Fermi motion changes drastically the shape of d sigma/dt, to the point that the ratio of this cross-section to the free one becomes very sensitive to the precise value of t chosen, or the size of the bin used in an experimental analysis. Hence, this particular region of t does not seem to be the most indicated to find effects of a possible phi absorption in the deuteron. This reaction is studied theoretically as a function of t and the results are contrasted with recent experiments at LEPS and Jefferson Lab. The effect of the experimental angular cuts at LEPS is also discussed, providing guidelines for future experimental analyses of the reaction. |
| Address |
[Sekihara, T.] Kyoto Univ, Grad Sch Sci, Dept Phys, Kyoto 6068502, Japan, Email: sekihara@th.phys.titech.ac.jp |
| Corporate Author |
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Thesis |
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| Publisher |
Springer |
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 |
1434-6001 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:000300285400001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration  |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
912 |
| Permanent link to this record |
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| Author |
Nagahiro, H.; Hirenzaki, S.; Oset, E.; Ramos, A. |
| Title |
eta '-Nucleus optical potential and possible eta ' bound states |
Type |
Journal Article |
| Year |
2012 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
709 |
Issue |
1-2 |
Pages |
87-92 |
| Keywords |
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| Abstract |
Starting from a recent model of the eta'N interaction, we evaluate the eta'-nucleus optical potential, including the contribution of lowest order in density, t rho/2m(eta'), together with the second-order terms accounting for eta' absorption by two nucleons. We also calculate the formation cross section of the eta' bound states from (pi(+), p) reactions on nuclei. The eta'-nucleus potential suffers from uncertainties tied to the poorly known eta'N interaction, which can be partially constrained by the experimental modulus of the eta'N scattering length and/or the recently measured transparency ratios in eta' nuclear photoproduction. Assuming an attractive interaction and taking the claimed experimental value vertical bar a(eta'N)vertical bar = 0.1 fm, we obtain an eta' optical potential in nuclear matter at saturation density of V eta' = -(8.7 + 1.8i) MeV, not attractive enough to produce eta' bound states in light nuclei. Larger values of the scattering length give rise to deeper optical potentials, with moderate enough imaginary parts. For a value vertical bar a(eta'N)vertical bar = 0.3 fm, which can still be considered to lie within the uncertainties of the experimental constraints, the spectra of light and medium nuclei show clear structures associated to eta'-nuclear bound states and to threshold enhancements in the unbound region. |
| Address |
[Nagahiro, H.; Hirenzaki, S.] Nara Womens Univ, Dept Phys, Nara 6308506, Japan, Email: nagahiro@rcnp.osaka-u.ac.jp |
| Corporate Author |
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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 |
WOS:000302111200013 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
979 |
| Permanent link to this record |
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| Author |
Nanova, M. et al; Oset, E. |
| Title |
Transparency ratio in gamma A -> eta ' A ' and the in-medium eta ' width |
Type |
Journal Article |
| Year |
2012 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
710 |
Issue |
4-5 |
Pages |
600-606 |
| Keywords |
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| Abstract |
The photoproduction of eta'-mesons off different nuclei has been measured with the CBELSA/TAPS detector system for incident photon energies between 1500-2200 MeV. The transparency ratio has been deduced and compared to theoretical calculations describing the propagation of eta'-mesons in nuclei. The comparison indicates a width of the eta'-meson of the order of Gamma = 15-25 MeV at rho = rho(0) for an average momentum p(eta') = 1050 MeV/c, at which the eta'-meson is produced in the nuclear rest frame. The inelastic eta'N cross section is estimated to be 3-10 mb. Parameterizing the photoproduction cross section of eta'-mesons by sigma(A) = sigma(0)A(alpha), a value of alpha = 0.84 +/- 0.03 has been deduced. |
| Address |
[Nanova, M.; Metag, V.; Makonyi, K.; Gregor, R.; Lugert, S.; Novotny, R.; Pant, L. M.; Pfeiffer, M.; Roy, A.; Schadmand, S.; Trnka, D.; Varma, R.] Univ Giessen, Inst Phys 2, D-35390 Giessen, Germany, Email: mariana.nanova@exp2.physik.uni-giessen.de |
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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 |
|
| Notes |
WOS:000303221800012 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1008 |
| Permanent link to this record |
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| Author |
Oset, E.; Martinez Torres, A.; Khemchandani, K.P.; Roca, L.; Yamagata-Sekihara, J. |
| Title |
Two, three, many body systems involving mesons |
Type |
Journal Article |
| Year |
2012 |
Publication |
Progress in Particle and Nuclear Physics |
Abbreviated Journal |
Prog. Part. Nucl. Phys. |
| Volume |
67 |
Issue |
2 |
Pages |
455-460 |
| Keywords |
Meson many body; Chiral dynamics; Dynamically generated resonances |
| Abstract |
In this talk we show recent developments on few body systems involving mesons. We report on an approach to Faddeev equations using chiral unitary dynamics, where an explicit cancellation of the two body off shell amplitude with three body forces stemming from the same chiral Lagrangians takes place. This removal of the unphysical off shell part of the amplitudes is most welcome and renders the approach unambiguous, showing that only on shell two body amplitudes need to be used. Within this approach, systems of two mesons and one baryon are studied, reproducing properties of the low lying 1/2(+) states. On the other hand we also report on multirho and K* multirho states which can be associated to known meson resonances of high spin. |
| Address |
[Oset, E.; Yamagata, J.] Ctr Mixto CSIC UV, Inst Fis Corpuscular, Inst Invest Paterna, Valencia 46071, Spain, Email: oset@ific.uv.es |
| Corporate Author |
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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 |
0146-6410 |
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:000303282200060 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
998 |
| Permanent link to this record |
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| Author |
Bayar, M.; Oset, E. |
| Title |
Improved fixed center approximation of the Faddeev equations for the (K)over-bar N N system with S=0 |
Type |
Journal Article |
| Year |
2012 |
Publication |
Nuclear Physics A |
Abbreviated Journal |
Nucl. Phys. A |
| Volume |
883 |
Issue |
|
Pages |
57-68 |
| Keywords |
Fixed center approximation; (K)over-bar N N system |
| Abstract |
We extend the Fixed Center Approximation (FCA) to the Faddeev equations for the (K) over bar N N system with S = 0, including the charge exchange mechanisms in the (K) over bar rescattering which have been ignored in former works within the FCA. We obtain similar results to those found before, but the binding is reduced by 6 MeV. At the same time we also evaluate the explicit contribution the pi N Sigma intermediate state in the three body system and find that it produces and additional small decrease in the binding of about 3 MeV. The system appears bound by about 35 MeV and the width omitting two body absorption, is about 50 MeV. |
| Address |
[Bayar, M.; Oset, E.] Inst Invest Paterna, Inst Fis Corpuscular, Ctr Mixto, CSIC,UV, Valencia 46071, Spain, Email: melahat@ific.uv.es |
| Corporate Author |
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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 |
0375-9474 |
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:000304628900005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1042 |
| Permanent link to this record |
