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Author Gambino, P.; Melis, A.; Simula, S. url  doi
openurl 
  Title Extraction of heavy-quark-expansion parameters from unquenched lattice data on pseudoscalar and vector heavy-light meson masses Type Journal Article
  Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 96 Issue 1 Pages 014511 - 17pp  
  Keywords  
  Abstract We present a precise lattice computation of pseudoscalar and vector heavy-light meson masses for heavy-quark masses ranging from the physical charm mass up to similar or equal to 4 times the physical b-quark mass. We employ the gauge configurations generated by the European Twisted Mass Collaboration (ETMC) with N-f = 2 + 1 + 1 dynamical quarks at three values of the lattice spacing (a similar or equal to 0.062; 0.082; 0.089 fm) with pion masses in the range M-pi similar or equal to 210-450 MeV. The heavy-quark mass is simulated directly on the lattice up to similar or equal to 3 times the physical charm mass. The interpolation to the physical b-quark mass is performed using the ETMC ratio method, based on ratios of the meson masses computed at nearby heavy-quark masses, and adopting the kinetic mass scheme. The extrapolation to the physical pion mass and to the continuum limit yields m(b)(kin) (1 GeV) = 4.61(20) GeV, which corresponds to (m) over bar (b) ((m) over bar (b)) 4.26(18) GeV in the (MS) over bar scheme. The lattice data are analyzed in terms of the heavy-quark expansion (HQE) and the matrix elements of dimension-four and dimension-five operators are extracted with a good precision, namely,(Lambda) over bar = 0.552(26) GeV, mu(2)(pi) = 0.321(32) GeV2, and mu(2)(G)(m(b)) = 0.253(25) GeV2. The data also allow for a rough estimate of the dimension-six operator matrix elements. As the HQE parameters play a crucial role in the inclusive determination of the Cabibbo-Kobayashi-Maskawa matrix elements V-ub and V-cb, their precise determination on the lattice may eventually validate and improve the analyses based on fits to the semileptonic moments.  
  Address [Gambino, P.] Univ Turin, Dipartimento Fis, Via P Giuria 1, I-10125 Turin, 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 2470-0010 ISBN Medium  
  Area Expedition Conference (up)  
  Notes WOS:000406298500005 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3224  
Permanent link to this record
 

 
Author Lubicz, V.; Melis, A.; Simula, S. url  doi
openurl 
  Title Masses and decay constants of D-(s)* and B-(s)* mesons with N-f=2+1+1 twisted mass fermions Type Journal Article
  Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 96 Issue 3 Pages 034524 - 10pp  
  Keywords  
  Abstract We present a lattice calculation of the masses and decay constants of D-(s)* and B-(s)* mesons using the gauge configurations produced by the European Twisted Mass Collaboration (ETMC) with N-f=2+1+1 dynamical quarks at three values of the lattice spacing a similar to(0.06-0.09) fm. Pion masses are simulated in the range M-pi similar or equal to(210-450) MeV, while the strange and charm sea-quark masses are close to their physical values. We compute the ratios of vector to pseudoscalar masses and decay constants for various values of the heavy-quark mass mh in the range 0.7m(c)(phys) less than or similar to m(h) less than or similar to 3m(c)(phys). In order to reach the physical b-quark mass, we exploit the Heavy Quark Effective Theory prediction that, in the static limit of infinite heavy-quark mass, the considered ratios are equal to one. At the physical point our results are: M-D*/M-D=1.0769(79), M-D*(s)/M-Ds=1.0751(56), f(D)*/f(D)=1.078(36), f(D)*s/f(Ds)=1.087(20), M-B*/M-B=1.0078(15), M-B*(s)/M-Bs=1.0083(10), f(B)*/f(B)=0.958(22) and f(B)*s/f(Bs)=0.974(10). Combining them with the experimental values of the pseudoscalar meson masses (used as input to fix the quark masses) and the values of the pseudoscalar decay constants calculated by ETMC, we get: M-D*=2013(14) MeV, M-D*(s)=2116(11) MeV, f(D)*=223.5(8.4) MeV, f(D)*(s)=268.8(6.6) MeV, M-B*=5320.5(7.6) MeV, M-B*(s)=5411.36(5.3) MeV, f(B)*=185.9(7.2) MeV and f(B)*(s)=223.1(5.4) MeV.  
  Address [Lubicz, V.] Univ Roma Tre, Dip Matemat & Fis, I-00146 Rome, 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 2470-0010 ISBN Medium  
  Area Expedition Conference (up)  
  Notes WOS:000408626300006 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3282  
Permanent link to this record
 

 
Author Lopez-Ibañez, M.L.; Melis, A.; Jay Perez, M.; Vives, O. url  doi
openurl 
  Title Slepton non-universality in the flavor-effective MSSM Type Journal Article
  Year 2017 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 11 Issue 11 Pages 162 - 27pp  
  Keywords Quark Masses and SM Parameters; Supersymmetric Standard Model; Super-symmetry Breaking; Supersymmetric Effective Theories  
  Abstract Supersymmetric theories supplemented by an underlying flavor-symmetry G(f) provide a rich playground for model building aimed at explaining the flavor structure of the Standard Model. In the case where supersymmetry breaking is mediated by gravity, the soft-breaking Lagrangian typically exhibits large tree-level flavor violating e ff ects, even if it stems from an ultraviolet flavor-conserving origin. Building on previous work, we continue our phenomenological analysis of these models with a particular emphasis on leptonicflavor observables. We consider three representative models which aim to explain the flavor structure of the lepton sector, with symmetry groups G(f) = Delta (27), A(4); and S-3.  
  Address [Luisa Lopez-Ibanez, M.; Melis, Aurora; Jay Perez, M.; Vives, Oscar] Univ Valencia, Dept Fis Teor, Dr Moliner 50, Burjassot, Valencia, Spain, Email: m.luisa.lopez-ibanez@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 (up)  
  Notes WOS:000416356500006 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3382  
Permanent link to this record
 

 
Author de Medeiros Varzielas, I.; Lopez-Ibañez, M.L.; Melis, A.; Vives, O. url  doi
openurl 
  Title Controlled flavor violation in the MSSM from a unified Delta(27) flavor symmetry Type Journal Article
  Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 09 Issue 9 Pages 047 - 22pp  
  Keywords Beyond Standard Model; Supersymmetric Standard Model; Quark Masses and SM Parameters  
  Abstract We study the phenomenology of a unified supersymmetric theory with a flavor symmetry Delta(27). The model accommodates quark and lepton masses, mixing angles and CP phases. In this model, the Dirac and Majorana mass matrices have a unified texture zero structure in the (1, 1) entry that leads to the Gatto-Sartori-Tonin relation between the Cabibbo angle and ratios of the masses in the quark sectors, and to a natural departure from zero of the theta 13(l) angle in the lepton sector. We derive the flavor structures of the trilinears and soft mass matrices, and show their general non-universality. This causes large flavor violating effects. As a consequence, the parameter space for this model is constrained, allowing it to be (dis)proven by flavor violation searches in the next decade. Although the results are model specific, we compare them to previous studies to show similar flavor effects (and associated constraints) are expected in general in supersymmetric flavor models, and may be used to distinguish them.  
  Address [Varzielas, Ivo de Medeiros] Univ Lisbon, Inst Super Tecn, Dept Fis, CFTP, Ave Rovisco Pais 1, P-1049 Lisbon, Portugal, Email: ivo.de@udo.edu;  
  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 (up)  
  Notes WOS:000444676300004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3735  
Permanent link to this record
 

 
Author Lopez-Ibañez, M.L.; Melis, A.; Meloni, D.; Vives, O. url  doi
openurl 
  Title Lepton flavor violation and neutrino masses from A(5) and CP in the non-universal MSSM Type Journal Article
  Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 06 Issue 6 Pages 047 - 34pp  
  Keywords Beyond Standard Model; Neutrino Physics; Quark Masses and SM Parameters; Supersymmetric Standard Model  
  Abstract We analyze the phenomenological consequences of embedding a flavor symmetry based on the groups A(5) and CP in a supersymmetric framework. We concentrate on the leptonic sector, where two different residual symmetries are assumed to be conserved at leading order for charged and neutral leptons. All possible realizations to generate neutrino masses at tree level are investigated. Sizable flavor violating effects in the charged lepton sector are unavoidable due to the non-universality of soft-breaking terms determined by the symmetry. We derive testable predictions for the neutrino spectrum, lepton mixing and flavor changing processes with non-trivial relations among observables.  
  Address [Lopez-Ibanez, M. L.; Meloni, Davide] Univ Roma Tre, Dipartimento Matemat & Fis, Via Vasca Navale 84, I-00146 Rome, Italy, Email: maloi2@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 (up)  
  Notes WOS:000471630100001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4057  
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