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Author Pavon Valderrama, M.
Title Power counting and perturbative one pion exchange in heavy meson molecules Type Journal Article
Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 85 Issue 11 Pages 114037 - 21pp
Keywords
Abstract We discuss the possible power counting schemes that can be applied in the effective field theory description of heavy meson molecules, such as the X(3872) or the recently discovered Z(b)(10610) and Z(b)(10650) states. We argue that the effect of coupled channels is suppressed by at least two orders in the effective field theory expansion, meaning that they can be safely ignored at lowest order. The role of the one pion exchange potential between the heavy mesons, and, in particular, the tensor force, is also analyzed. By using techniques developed in atomic physics for handling power-law singular potentials, which have been also successfully employed in nuclear physics, we determine the range of center-of-mass momenta for which the tensor piece of the one pion exchange potential is perturbative. In this momentum range, the one pion exchange potential can be considered a subleading order correction, leaving at lowest order a very simple effective field theory consisting only of contact-range interactions.
Address Univ Valencia, Inst Fis Corpuscular IFIC, Ctr Mixto CSIC, Inst Invest Paterna, E-46071 Valencia, Spain, Email: m.pavon.valderrama@ific.uv.es
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000305560900006 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1065
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Author Castorina, E.; Franca, U.; Lattanzi, M.; Lesgourgues, J.; Mangano, G.; Melchiorri, A.; Pastor, S.
Title Cosmological lepton asymmetry with a nonzero mixing angle theta(13) Type Journal Article
Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 86 Issue 2 Pages 023517 - 11pp
Keywords
Abstract While the baryon asymmetry of the Universe is nowadays well measured by cosmological observations, the bounds on the lepton asymmetry in the form of neutrinos are still significantly weaker. We place limits on the relic neutrino asymmetries using some of the latest cosmological data, taking into account the effect of flavor oscillations. We present our results for two different values of the neutrino mixing angle theta(13), and show that for large theta(13) the limits on the total neutrino asymmetry become more stringent, diluting even large initial flavor asymmetries. In particular, we find that the present bounds are still dominated by the limits coming from big bang nucleosynthesis, while the limits on the total neutrino mass from cosmological data are essentially independent of theta(13). Finally, we perform a forecast for Cosmic Origins Explorer, taken as an example of a future cosmic microwave background experiment, and find that it could improve the limits on the total lepton asymmetry approximately by up to a factor 6.6.
Address [Castorina, Emanuele] SISSA, I-34136 Trieste, Italy
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000306320000003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1093
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Author Nieves, J.; Pavon Valderrama, M.
Title Heavy quark spin symmetry partners of the X(3872) Type Journal Article
Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 86 Issue 5 Pages 056004 - 18pp
Keywords
Abstract We explore the consequences of heavy quark spin symmetry for the charmed meson-antimeson system in a contact-range (or pionless) effective field theory. As a trivial consequence, we theorize the existence of a heavy quark spin symmetry partner of the X(3872), with J(PC) = 2(++), which we call X(4012) in reference to its predicted mass. If we additionally assume that the X(3915) is a 0(++) heavy spin symmetry partner of the X(3872), we end up predicting a total of six D-(*())(D) over bar (()*()) molecular states. We also discuss the error induced by higher order effects such as finite heavy quark mass corrections, pion exchanges and coupled channels, allowing us to estimate the expected theoretical uncertainties in the position of these new states.
Address [Nieves, J.; Pavon Valderrama, M.] Univ Valencia, Inst Fis Corpuscular IFIC, Ctr Mixto CSIC, Inst Invest Paterna, E-46071 Valencia, Spain, Email: m.pavon.valderrama@ific.uv.es
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000308869400013 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1162
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Author BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A.
Title Search for the decay modes B-+/- -> h(+/-)tau l Type Journal Article
Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 86 Issue 1 Pages 012004 - 14pp
Keywords
Abstract We present a search for the lepton flavor violating decay modes B-+/- -> h(+/-)tau l (h = K, pi; l = e, mu) using the BABAR data sample, which corresponds to 472 x 10(6) B (B) over bar pairs. The search uses events where one B meson is fully reconstructed in one of several hadronic final states. Using the momenta of the reconstructed B, h, and l candidates, we are able to fully determine the tau four-momentum. The resulting tau candidate mass is our main discriminant against combinatorial background. We see no evidence for B-+/- -> h(+/-)tau l decays and set a 90% confidence level upper limit on each branching fraction at the level of a few times 10(-5).
Address [Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, Lab Annecy Le Vieux Phys Particules LAPP, CNRS, IN2P3, F-74941 Annecy Le Vieux, France
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000306413200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1107
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Author Aguilar, A.C.; Binosi, D.; Papavassiliou, J.
Title Unquenching the gluon propagator with Schwinger-Dyson equations Type Journal Article
Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 86 Issue 1 Pages 014032 - 24pp
Keywords
Abstract In this article we use the Schwinger-Dyson equations to compute the nonperturbative modifications caused to the infrared finite gluon propagator (in the Landau gauge) by the inclusion of a small number of quark families. Our basic operating assumption is that the main bulk of the effect stems from the "one-loop dressed'' quark loop contributing to the full gluon self-energy. This quark loop is then calculated, using as basic ingredients the full quark propagator and quark-gluon vertex; for the quark propagator we use the solution obtained from the quark-gap equation, while for the vertex we employ suitable Ansatze, which guarantee the transversality of the answer. The resulting effect is included as a correction to the quenched gluon propagator, obtained in recent lattice simulations. Our main finding is that the unquenched propagator displays a considerable suppression in the intermediate momentum region, which becomes more pronounced as we increase the number of active quark families. The influence of the quarks on the saturation point of the propagator cannot be reliably computed within the present scheme; the general tendency appears to be to decrease it, suggesting a corresponding increase in the effective gluon mass. The renormalization properties of our results, and the uncertainties induced by the unspecified transverse part of the quark-gluon vertex, are discussed. Finally, the gluon propagator is compared with the available unquenched lattice data, showing rather good agreement.
Address [Aguilar, A. C.] Univ Estadual Campinas, UNICAMP, Inst Fis Gleb Wataghin, BR-13083859 Campinas, SP, Brazil
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000306929400003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1127
Permanent link to this record