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Author Kaskulov, M.; Hernandez, E.; Oset, E.
Title On the background in the gamma p -> omega(pi(0)gamma)p reaction and mixed event simulation Type Journal Article
Year 2010 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 46 Issue 2 Pages 223-230
Keywords
Abstract (down) In this paper we evaluate sources of background of the gamma p -> omega p reaction, with the omega detected through its pi(0)gamma decay channel, to compare with the experiment carried out at ELSA. We find background from gamma p -> pi(0)pi(0)p followed by decay of a pi(0) into two gamma, recombining one pi(0) and one gamma, and from the gamma p -> pi(0)eta p reaction with subsequent decay of the eta into two photons. This background accounts for the data at pi(0)gamma invariant masses beyond 700 MeV, but strength is missing at lower invariant masses which was attributed to photon misidentification events, which we simulate to get a good reproduction of the experimental background. Once this is done, we perform an event mixing simulation to reproduce the calculated background and we find that the method provides a good description of the background. A closer look reveals this is accidental. We show that the mixed event generated background in the region of the omega mass and beyond is completely tied to the events at low pi(0)gamma invariant masses where the d sigma/dM(pi 0 gamma) distribution is much larger. This has as a consequence that the mixed event method produces the same background at high invariant masses independently of the actual background in that region, as a consequence of which, the method is unsuited to give the background at energies around the peak of the omega and beyond.
Address [Kaskulov, M.] Univ Giessen, Inst Theoret Phys, D-35392 Giessen, Germany, Email: murat.kaskulov@theo.physik.uni-giessen.de
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes ISI:000284869600008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 313
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Author Abreu, L.M.; Song, J.; Brandao, P.C.S.; Oset, E.
Title A note on the tensor and vector exchange contributions to K (K)over-bar → K (K)over-bar, D(D)over-bar → D(D)over-bar and π+π- → π+π- reactions Type Journal Article
Year 2024 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 60 Issue 3 Pages 76 - 10pp
Keywords
Abstract (down) In this note we study the tensor and vector exchange contributions to the elastic reactions involving the pseudoscalars mesons pi(+) pi(-), K+ K- and D+D-. In the case of the tensor-exchange contributions we assume that an intermediate tensor f(2)(1270) is dynamically generated from the interaction of two virtual rho mesons, with the use of a pole approximation. The calculation of the two-loop amplitude is facilitated since the triangle loops can be factorized and computed separately. The results show very small contributions coming from the tensor-exchange mechanisms when compared with those from the vector-exchange processes. We compare our results for pi pi and K (K) over bar scattering with those obtained in other works where the f2(1270) is considered as an ordinary q (q) over bar meson. Our picture provides a smaller contribution but of similar order of magnitude for pion scattering and stabilizes the results in the case of K (K) over bar, allowing us to make estimates for D (D) over bar scattering.
Address [Abreu, Luciano M.; Brandao, Pedro C. S.] Univ Fed Bahia, Inst Fis, Campus Ondina, BR-40170115 Salvador, BA, Brazil, Email: luciano.abreu@ufba.br;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes WOS:001195442000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6036
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Author Souza, E.V.; Ferreira, M.N.; Aguilar, A.C.; Papavassiliou, J.; Roberts, C.D.; Xu, S.S.
Title Pseudoscalar glueball mass: a window on three-gluon interactions Type Journal Article
Year 2020 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 56 Issue 1 Pages 25 - 7pp
Keywords
Abstract (down) In pure-glue QCD, gluon-gluon scattering in the J(PC) = 0(-+) channel is described by a very simple equation, especially if one considers just the leading contribution to the scattering kernel. Of all components in this kernel, only the three-gluon vertex, V-mu nu rho, is poorly constrained by contemporary analyses; hence, calculations of 0(-+) glueball properties serve as a clear window onto the character and form of V-mu nu rho. This is important given that many modern calculations of V-mu nu rho predict the appearance of an infrared suppression in the scalar function which comes to modulate the bare vertex after the nonperturbative resummation of interactions. Such behaviour is a peculiar prediction; but we find that the suppression is essential if one is to achieve agreement with lattice-QCD predictions for the 0(-+) glueball mass. Hence, it is likely that this novel feature of V-mu nu rho is real and has observable implications for the spectrum, decays and interactions of all QCD bound-states.
Address [Souza, E. V.] Fed Inst Educ Sci & Technol Piaui, BR-64605500 Picos, Piaui, Brazil, Email: emanuel.veras@ifpi.edu.br;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes WOS:000513948400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4291
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Author Xiao, C.W.; Oset, E.
Title Three methods to detect the predicted D(D)over-bar scalar meson X(3700) Type Journal Article
Year 2013 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 49 Issue 4 Pages 52 - 6pp
Keywords
Abstract (down) In analogy to the f(0)(500), which appears as a pi pi resonance in chiral unitary theory, and the f(0)(980), which appears as a quasibound K (K) over bar state, the extension of this approach to the charm sector also predicts a quasibound D (D) over bar state with mass around 3720 MeV, named as X(3700), for which some experimental support is seen in the e(+)e(-) -> J/psi D (D) over bar reaction close to the D (D) over bar threshold. In the present work we propose three different experiments to observe it as a clear peak. The first one is the radiative decay of the psi(3770), psi(3770) -> gamma X(3700) -> gamma eta eta'. The second one proposes the analogous reaction psi(4040) -> gamma X(3700) -> gamma eta eta' and the third reaction is the e(+)e(-) -> J/psi X(3700) -> J/psi eta eta'. Neat peaks are predicted for all the reactions and the calculated rates are found within measurable range in present facilities.
Address Univ Valencia, CSIC, Inst Invest Paterna, Ctr Mixto,Dept Fis Teor, Valencia 46071, Spain, Email: xiaochw@ific.uv.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes WOS:000318424800011 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1443
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Author Oset, E.
Title On the ambiguities of sign determination of the S-matrix from energy levels in a finite box Type Journal Article
Year 2013 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 49 Issue 3 Pages 32 - 4pp
Keywords
Abstract (down) In a recent paper the authors make a study on the determination of the S-matrix elements for scattering of particles in the infinite volume from the energy levels in a finite box for the case of multiple channels. The study is done with a toy model in 1+1 dimension and the authors find that there is some ambiguity in the sign of nondiagonal matrix elements, casting doubts on whether the needed observables in the infinite volume can be obtained from the energy levels of the box. In this paper I present an easy derivation, confirming the ambiguity of the sign and argue that this, however, does not put restrictions in the determination of observables.
Address Ctr Mixto Univ Valencia CSIC, Inst Invest Paterna, Dept Fis Teor, Valencia 46071, Spain, Email: oset@ific.uv.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes WOS:000317855000004 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1427
Permanent link to this record