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Author de Salas, P.F.; Pastor, S. url  doi
openurl 
  Title Relic neutrino decoupling with flavour oscillations revisited Type Journal Article
  Year 2016 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.  
  Volume 07 Issue 7 Pages 051 - 18pp  
  Keywords cosmological neutrinos; particle physics – cosmology connection; physics of the; early universe; neutrino properties  
  Abstract (down) We study the decoupling process of neutrinos in the early universe in the presence of three-flavour oscillations. The evolution of the neutrino spectra is found by solving the corresponding momentum-dependent kinetic equations for the neutrino density matrix, including for the first time the proper collision integrals for both diagonal and off-diagonal elements. This improved calculation modifies the evolution of the off-diagonal elements of the neutrino density matrix and changes the deviation from equilibrium of the frozen neutrino spectra. However, it does not vary the contribution of neutrinos to the cosmological energy density in the form of radiation, usually expressed in terms of the effective number of neutrinos, N-eff. We find a value of N-eff = 3.045, in agreement with previous theoretical calculations and consistent with the latest analysis of Planck data. This result does not depend on the ordering of neutrino masses. We also consider the effect of non-standard neutrino-electron interactions (NSI), predicted in many theoretical models where neutrinos acquire mass. For two sets of NSI parameters allowed by present data, we find that Neff can be reduced down to 3.040 or enhanced up to 3.059.  
  Address [de Salas, Pablo F.; Pastor, Sergio] Univ Valencia, CSIC, Inst Fis Corpuscular, Parc Cient UV,C Catedrat Jose Beltran 2, E-46980 Paterna, Valencia, Spain, Email: pabrerde@ific.uv.es;  
  Corporate Author Thesis  
  Publisher Iop Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1475-7516 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000381830000052 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 2784  
Permanent link to this record
 

 
Author Liang, W.H.; Ban, T.; Oset, E. url  doi
openurl 
  Title B0 → K(*)0X, B- K(*) -X, Bs-η(η1;φ)X from the X(3872) molecular perspective Type Journal Article
  Year 2024 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 109 Issue 5 Pages 054030 - 9pp  
  Keywords  
  Abstract (down) We study the decays B over bar 0 – over bar K0X, B- – K-X, B over bar 0s – eta(eta 1)X, B over bar 0 – over bar K*0X, B- – K*-X, B over bar 0s – phi X, with X equivalent to X(3872), from the perspective of the X(3872) being a molecular state made from the interaction of the D*+D-; D*0 over bar D0, and c:c: components. We consider both the external and internal emission decay mechanisms and find an explanation for the over bar K0X and K-X production rates, based on the mass difference of the charged and neutral D*D over bar components. We also find that the internal and external emission mechanisms add constructively in the B over bar 0 – over bar K0X, B- – K-X reactions, while they add destructively in the case of widths of the present measurements and allows us to make predictions for the unmeasured modes of B over bar 0s – eta(eta 1)X(3872) and B- – K*-X(3872). The future measurement of these decay modes will help us get a better perspective on the nature of the X(3872) and the mechanisms present in production reactions of that state. B over bar 0 – over bar K*0X, B- – K*-X reactions. This feature explains the decay  
  Address [Liang, Wei -Hong; Ban, Ting; Oset, Eulogio] Guangxi Normal Univ, Dept Phys, Guilin 541004, Peoples R China, Email: liangwh@gxnu.edu.cn;  
  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 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:001195452700005 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 6037  
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Author Guo, F.K.; Hidalgo-Duque, C.; Nieves, J.; Ozpineci, A.; Pavon Valderrama, M. url  doi
openurl 
  Title Detecting the long-distance structure of the X(3872) Type Journal Article
  Year 2014 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C  
  Volume 74 Issue 5 Pages 2885 - 10pp  
  Keywords  
  Abstract (down) We study the decay within a molecular picture for the state. This decay mode is more sensitive to the long-distance structure of the resonance than its and decays, which are mainly controlled by the details of the wave function at short distances. We show that the final state interaction can be important, and that a precise measurement of this partial decay width can provide valuable information on the interaction strength between the charm mesons.  
  Address [Guo, Feng-Kun] Univ Bonn, Helmholtz Inst Strahlen & Kernphys, D-53115 Bonn, Germany, Email: fkguo@hiskp.uni-bonn.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 1434-6044 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000340092200001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1889  
Permanent link to this record
 

 
Author Molina, R.; Nagahiro, H.; Hosaka, A.; Oset, E. url  doi
openurl 
  Title Decay of vector-vector resonances into gamma and a pseudoscalar meson Type Journal Article
  Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 83 Issue 9 Pages 094030 - 12pp  
  Keywords  
  Abstract (down) We study the decay of dynamically generated resonances from the interaction of two vectors into a gamma and a pseudoscalar meson. The dynamics requires anomalous terms involving vertices with two vectors and a pseudoscalar, which renders it special. We compare our result with data on K-2*(+) (1430) -> K+ gamma and K-2*(0) (1430) -> K-0 gamma and find a good agreement with the data for the K-2*(+) (1430) case and a width considerably smaller than the upper bound measured for the K-2*(0) (1430) meson. We also investigate the decay into pi(+) gamma of one a(2) state, tentatively associated to the a(2)(1320), obtaining qualitative agreement with data.  
  Address [Molina, R.; Oset, E.] Univ Valencia, CSIC, Ctr Mixto, Inst Invest Paterna,Dept Fis Teor, Valencia 46071, Spain  
  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 ISI:000291006200002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 636  
Permanent link to this record
 

 
Author Aceti, F.; Dai, L.R.; Oset, E. url  doi
openurl 
  Title a(1)(1420) peak as the pi f(0)(980) decay mode of the a(1)(1260) Type Journal Article
  Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 94 Issue 9 Pages 096015 - 9pp  
  Keywords  
  Abstract (down) We study the decay mode of the a(1)(1260) into a pi(+) in p wave and the f(0)(980) that decays into pi(+)pi(-) in s wave. The mechanism proceeds via a triangular mechanism where the a(1)(1260) decays into K*K-, the K* decays to an external pi(+) and an internal K that fuses with the (K) over bar producing the f(0)(980) resonance. The mechanism develops a singularity at a mass of the a(1)(1260) around 1420 MeV, producing a peak in the cross section of the pp reaction, used to generate the mesonic final state, which provides a natural explanation of all the features observed in the COMPASS experiment, where a peak observed at this energy is tentatively associated to a new resonance called a(1)(1420). On the other hand, the triangular singularity studied here gives rise to a remarkable feature, where a peak is seen for a certain decay channel of a resonance at an energy about 200 MeV higher than its nominal mass.  
  Address [Aceti, F.; Dai, L. R.; Oset, E.] Univ Valencia, Dept Fis Teor, CSIC, Inst Invest Paterna, Aptdo 22085, Valencia 46071, Spain, Email: aceti@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 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000388824300007 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2912  
Permanent link to this record
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