Browsing by Author "Negele, J. W."

Now showing items 1-20 of 24

    • Article  

      Axial nucleon and nucleon to Δ form factors and the Goldberger-Treiman relations from lattice QCD 

      Alexandrou, Constantia; Koutsou, Giannis; Leontiou, Theodoros; Negele, J. W.; Tsapalis, Antonios (2007)
      We evaluate the nucleon axial form factor, GA(q2), and induced pseudoscalar form factor, Gp(q2), as well as the pion-nucleon form factor, GπNN(q2), in lattice QCD. We also evaluate the corresponding nucleon to Δ transition ...
    • Conference Object  

      Calculation of the decay width of decuplet baryons 

      Petschlies, Marcus; Alexandrou, Constantia; Negele, J. W.; Pochinsky, A. V.; Syritsyn, S. S. (Proceedings of Science (PoS), 2015)
      We calculate the coupling constant and decay width of the decuplet to octet baryon transitions in lattice QCD using the transfer matrix method. The transition amplitude is related to the coupling constant and via the Fermi's ...
    • Article  

      Calculation of the N to Δ electromagnetic transition matrix element 

      Alexandrou, Constantia; de Forcrand, Ph; Lippert, Th; Neff, H.; Negele, J. W.; Schilling, K.; Schroers, W.; Tsapalis, Antonios (2003)
      We present results on the ratio of electric quadrupole to magnetic dipole amplitudes, REM = GE2/GM1, for the transition γN → Δ from lattice QCD. We consider both the quenched and the 2-flavor theory.
    • Article  

      Comparison of mean-field and exact Monte Carlo solutions of a one-dimensional nuclear model 

      Alexandrou, Constantia; Myczkowski, J.; Negele, J. W. (1989)
      The ground states of nuclear matter and finite nuclei are calculated for a one-dimensional model having a two-body potential with strong short-range repulsion and long-range attraction. Mean-field theory with a phenomenological ...
    • Conference Object  

      Determination of the Δ resonance width from lattice QCD 

      Petschlies, Marcus; Alexandrou, Constantia; Negele, J. W. (Proceedings of Science (PoS), 2013)
      A method suitable for extracting resonance parameters of unstable baryons in lattice QCD is examined. The method is applied to the strong decay of the Δ to a pion-nucleon state, extracting the pND coupling constant and Δ ...
    • Article  

      Determination of the Δ(1232) axial and pseudoscalar form factors from lattice QCD 

      Alexandrou, Constantia; Gregory, E. B.; Korzec, T.; Koutsou, Giannis; Negele, J. W.; Sato, T.; Tsapalis, Antonios (2013)
      We present a lattice QCD calculation of the Δ(1232) matrix elements of the axial-vector and pseudoscalar currents. The decomposition of these matrix elements into the appropriate Lorentz invariant form factors is carried ...
    • Article  

      Determination of Δ-resonance parameters from lattice QCD 

      Petschlies, Marcus; Alexandrou, Constantia; Negele, J. W.; Strelchenko, A.; Tsapalis, Antonios (2013)
      A method suitable for extracting resonance parameters of unstable baryons in lattice QCD is examined. The method is applied to the strong decay of the Δ to a pion-nucleon state, extracting the πNΔ coupling constant and Δ ...
    • Article  

      Electromagnetic form factors of the Ω- In lattice QCD 

      Alexandrou, Constantia; Korzec, T.; Koutsou, Giannis; Negele, J. W.; Proestos, Y. (2010)
      We present results on the omega baryon (Ω-) electromagnetic form factors using Nf=2+1 domain-wall fermion configurations for three pion masses in the range of about 350 to 300 MeV. We compare results obtained using domain-wall ...
    • Article  

      Erratum: Axial nucleon and nucleon to Δ form factors and the Goldberger-Treiman relations from lattice QCD (Phys. Rev. D (2007) 76 (094511)) 

      Alexandrou, Constantia; Koutsou, Giannis; Leontiou, Theodoros; Negele, J. W.; Tsapalis, Antonios (2009)
    • Article  

      First principles calculations of nucleon and pion form factors: Understanding the building blocks of nuclear matter from lattice QCD 

      Alexandrou, Constantia; Bistrovic, B.; Edwards, R. G.; De Forcrand, P.; Fleming, G.; Hägler, P.; Negele, J. W.; Orginos, K.; Pochinsky, A.; Renner, D. B.; Richards, D. G.; Schroers, W.; Tsapalis, Antonios (2005)
      Lattice QCD is an essential complement to the current and anticipated DOE-supported experimental program in hadronic physics. In this paper we address several key questions central to our understanding of the building ...
    • Article  

      Momentum dependence of the N to Δ transition form factors 

      Alexandrou, Constantia; de Forcrand, Ph; Neff, H.; Negele, J. W.; Schroers, W.; Tsapalis, Antonios (2005)
      We present a new method to determine the momentum dependence of the N to Δ transition form factors and demonstrate its effectiveness in the quenched theory at β = 6.0 on a 323 × 64 lattice. We address a number of technical ...
    • Article  

      N to Δ electromagnetic transition form factors from lattice QCD 

      Alexandrou, Constantia; De Forcrand, Ph; Lippert, Th; Neff, H.; Negele, J. W.; Schilling, K.; Schroers, W.; Tsapalis, Antonios (2004)
      The magnetic dipole, the electric quadrupole, and the Coulomb quadrupole amplitudes for the transition γN→Δ are evaluated both in quenched lattice QCD at β=6.0 and using two dynamical Wilson fermions simulated at β=5.6. ...
    • Article  

      N-to-Δ axial transition form factors from lattice QCD 

      Alexandrou, Constantia; Leontiou, Theodoros; Negele, J. W.; Tsapalis, Antonios (2007)
      We evaluate the N to Δ axial transition form factors in lattice QCD with no dynamical sea quarks, with two degenerate flavors of dynamical Wilson quarks, and using domain wall valence fermions with three flavors of staggered ...
    • Article  

      N-to-Δ electromagnetic-transition form factors from lattice QCD 

      Alexandrou, Constantia; De Forcrand, P.; Neff, H.; Negele, J. W.; Schroers, W.; Tsapalis, Antonios (2005)
      The magnetic dipole (M1), the electric quadrupole (E2), and the Coulomb quadrupole (C2) amplitudes for γN → Δ are calculated in quenched lattice QCD. Using a new method, which combines an optimal choice of interpolating ...
    • Article  

      Nucleon electromagnetic form factors from lattice QCD 

      Alexandrou, Constantia; Koutsou, Giannis; Negele, J. W.; Tsapalis, Antonios (2006)
      We evaluate the isovector nucleon electromagnetic form factors in quenched and unquenched QCD on the lattice using Wilson fermions. In the quenched theory we use a lattice of spatial size 3 fm at β=6.0 enabling us to reach ...
    • Article  

      Nucleon to delta electromagnetic transition form factors in lattice QCD 

      Alexandrou, Constantia; Koutsou, Giannis; Neff, H.; Negele, J. W.; Schroers, W.; Tsapalis, Antonios (2008)
      The electromagnetic nucleon to Δ transition form factors are evaluated using two degenerate flavors of dynamical Wilson fermions and using dynamical sea staggered fermions with domain-wall valence quarks. The two subdominant ...
    • Article  

      Nucleon to Δ transition form factors with NF=2+1 domain wall fermions 

      Alexandrou, Constantia; Koutsou, Giannis; Negele, J. W.; Proestos, Y.; Tsapalis, Antonios (2011)
      We calculate the electromagnetic, axial, and pseudoscalar form factors of the nucleon to Δ(1232) transition using two dynamical light degenerate quarks and a dynamical strange quark simulated with the domain wall fermion ...
    • Article  

      Quark transverse charge densities in the Δ (1232) from lattice QCD 

      Alexandrou, Constantia; Korzec, T.; Koutsou, Giannis; Lorcé, C.; Negele, J. W.; Pascalutsa, V.; Tsapalis, Antonios; Vanderhaeghen, M. (2009)
      We extend the formalism relating electromagnetic form factors to transverse quark charge densities in the light-front frame to the case of a spin-3/2 baryon and calculate these transverse densities for the Δ (1232) isobar ...
    • Article  

      Stochastic calculation of tunneling in systems with many degrees of freedom 

      Alexandrou, Constantia; Negele, J. W. (1988)
      A new method is presented for the stochastic solution of tunneling problems in quantum many-body systems. The primary practical problem of trapping in local minima of the action is overcome by extending the standard ...
    • Article  

      Study of decuplet baryon resonances from lattice QCD 

      Petschlies, Marcus; Alexandrou, Constantia; Negele, J. W.; Pochinsky, A. V.; Syritsyn, S. N. (2016)
      A lattice QCD study of the strong decay width and coupling constant of decuplet baryons to an octet baryon-pion state is presented. The transfer matrix method is used to obtain the overlap of lattice states with decuplet ...