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Author Pinto-Gomez, F.; De Soto, F.; Ferreira, M.N.; Papavassiliou, J.; Rodriguez-Quintero, J. url  doi
openurl 
  Title Lattice three-gluon vertex in extended kinematics: Planar degeneracy Type Journal Article
  Year 2023 Publication Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 838 Issue Pages 137737 - 8pp  
  Keywords QCD; Three-gluon vertex; Lattice QCD; Schwinger-Dyson equations  
  Abstract We present novel results for the three-gluon vertex, obtained from an extensive quenched lattice simulation in the Landau gauge. The simulation evaluates the transversely projected vertex, spanned on a special tensorial basis, whose form factors are naturally parametrized in terms of individually Bosesymmetric variables. Quite interestingly, when evaluated in these kinematics, the corresponding form factors depend almost exclusively on a single kinematic variable, formed by the sum of the squares of the three incoming four-momenta, q, r, and p. Thus, all configurations lying on a given plane in the coordinate system (q2, r2, p2) share, to a high degree of accuracy, the same form factors, a property that we denominate planar degeneracy. We have confirmed the validity of this property through an exhaustive study of the set of configurations satisfying the condition q2 = r2, within the range [0, 5 GeV]. This drastic simplification allows for a remarkably compact description of the main bulk of the data, which is particularly suitable for future numerical applications. A semi-perturbative analysis reproduces the lattice findings rather accurately, once the inclusion of a gluon mass has cured all spurious divergences.  
  Address (down) [Pinto-Gomez, F.; De Soto, F.] Univ Pablo de Olavide, Dpto Sistemas Fis Quim & Nat, Seville 41013, Spain, Email: jose.rodriguez@dfaie.uhu.es  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0370-2693 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000953425400001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5503  
Permanent link to this record
 

 
Author Pino, F.; Roe, N.; Orero, A.; Falcon, C.; Rojas, S.; Benlloch, J.M.; Ros, D.; Pavia, J. doi  openurl
  Title Development of a variable-radius pinhole SPECT system with a portable gamma camera Type Journal Article
  Year 2011 Publication Revista Española de Medicina Nuclear Abbreviated Journal Rev. Esp. Med. Nucl.  
  Volume 30 Issue 5 Pages 286-291  
  Keywords SPECT; Small animal; Pinhole; Portable gamma camera; Continuous scintillator  
  Abstract Objective: To develop a small-animal SPECT system using a low cost commercial portable gamma camera equipped with a pinhole collimator, a continuous scintillation crystal and a position-sensitive photomultiplier tube. Material and methods: The gamma camera was attached to a variable radius system, which enabled us to optimize sensitivity and resolution by adjusting the radius of rotation to the size of the object. To investigate the capability of the SPECT system for small animal imaging, the dependence of resolution and calibration parameters on radius was assessed and acquisitions of small phantoms and mice were carried out. Results: Resolution values, ranging from 1.0 mm for a radius of 21.4 mm and 1.4 mm for a radius of 37.2 mm were obtained, thereby justifying the interest of a variable radius SPECT system. Conclusions: The image quality of phantoms and animals were satisfactory, thus confirming the usefulness of the system for small animal SPECT imaging.  
  Address (down) [Pino, F; Roe, N; Ros, D] Univ Barcelona, Fac Med, Unitat Biofis, Barcelona 7, Spain, Email: fpino@iconcologia.net  
  Corporate Author Thesis  
  Publisher Elsevier Science Inc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0212-6982 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000294659400004 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ elepoucu @ Serial 753  
Permanent link to this record
 

 
Author Pich, A.; Rodriguez-Sanchez, A. url  doi
openurl 
  Title Violations of quark-hadron duality in low-energy determinations of alpha(s) Type Journal Article
  Year 2022 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 07 Issue 7 Pages 145 - 42pp  
  Keywords The Strong Coupling; Semi-Leptonic Decays; Specific QCD Phenomenology; Chiral Lagrangian  
  Abstract Using the spectral functions measured in tau decays, we investigate the actual numerical impact of duality violations on the extraction of the strong coupling. These effects are tiny in the standard alpha(s)(m(tau)(2)) determinations from integrated distributions of the hadronic spectrum with pinched weights, or from the total tau hadronic width. The pinched-weight factors suppress very efficiently the violations of duality, making their numerical effects negligible in comparison with the larger perturbative uncertainties. However, combined fits of alpha(s) and duality-violation parameters, performed with non-protected weights, are subject to large systematic errors associated with the assumed modelling of duality-violation effects. These uncertainties have not been taken into account in the published analyses, based on specific models of quark-hadron duality.  
  Address (down) [Pich, Antonio] Univ Valencia, Dept Fis Teor, CSIC, IFIC, Parque Cient,Catedrat Jose Beltran 2, E-46980 Paterna, Spain, Email: Antonio.Pich@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 1029-8479 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000831256400009 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5303  
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Author Pich, A.; Rodriguez-Sanchez, A. url  doi
openurl 
  Title Updated determination of alpha(s)(m(tau)(2)) from tau decays Type Journal Article
  Year 2016 Publication Modern Physics Letters A Abbreviated Journal Mod. Phys. Lett. A  
  Volume 31 Issue 30 Pages 1630032 - 15pp  
  Keywords QCD; strong coupling; tau decays  
  Abstract Using the most recent release of the ALEPH tau decay data, we present a very detailed phenomenological update of the alpha(s)(m(tau)(2)) determination. We have exploited the sensitivity to the strong coupling in many different ways, exploring several complementary methodologies. All determinations turn out to be in excellent agreement, allowing us to extract a very reliable value of the strong coupling. We find alpha((nf =3))(s)(m(tau)(2)) = 0.328 +/- 0.012 which implies alpha((nf=5))(s)(M-Z(2)) = 0.1197 +/- 0.0014. We critically revise previous work, and point out the problems flawing some recent analyses which claim slightly smaller values.  
  Address (down) [Pich, Antonio; Rodriguez-Sanchez, Antonio] Univ Valencia, IFIC, CSIC, Dept Fis Teor, Apt Correus 22085, F-46071 Valencia, Spain, Email: Antonio.Pich@ific.uv.es;  
  Corporate Author Thesis  
  Publisher World Scientific Publ Co Pte Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0217-7323 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000383788500002 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 2818  
Permanent link to this record
 

 
Author Gomez Dumm, D.; Roig, P.; Pich, A.; Portoles, J. url  doi
openurl 
  Title tau -> pi pi pi nu(tau) decays and the a(1)(1260) off-shell width revisited Type Journal Article
  Year 2010 Publication Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 685 Issue 2-3 Pages 158-164  
  Keywords Hadron tau decays; Chiral Lagrangians; QCD; 1/N expansion  
  Abstract The tau -> pi pi pi nu(tau) decay is driven by the hadronization of the axial-vector current. Within the resonance chiral theory, and considering the large-N-C expansion, this process has been studied in Ref. [1] (D. Gomez Dumm, A. Pich, J. Portoles, 2004). In the light of later developments we revise here this previous work by including a new off-shell width for the lightest a(1) resonance that provides a good description of the tau -> pi pi pi nu(tau) spectrum and branching ratio. We also consider the role of the rho(1450) resonance in these observables. Thus we bring in an overall description of the tau -> pi pi pi nu(tau) process in excellent agreement with our present experimental knowledge.  
  Address (down) [Pich, A.; Portoles, J.] Univ Valencia, CSIC, Dept Fis Teor, IFIC, E-46071 Valencia, Spain, Email: Jorge.Portoles@ific.uv.es  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0370-2693 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000275148800010 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 488  
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