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Full-Text Articles in Physics
Nuclear Theory And Event Generators For Charge-Changing Neutrino Reactions, J. W. Van Orden, T. W. Donnelly
Nuclear Theory And Event Generators For Charge-Changing Neutrino Reactions, J. W. Van Orden, T. W. Donnelly
Physics Faculty Publications
Semi-inclusive CCν cross sections based on factorized cross sections are studied for a selection of spectral function models with the objective of facilitating the choice of models for use as input into event generators. The basic formalism for such cross sections is presented along with an introduction to constructing spectral functions for simple models based on the independent-particle shell model, the relativistic Fermi gas model (RFG), and a local density approximation (LDA) based on the RFG. Spectral functions for these models are shown for 16O along with a more sophisticated model which includes nucleon-nucleon interactions [AlvarezRuso et al., Prog. …
Muon Capture In Nuclei: An Ab Initio Approach Based On Green's Function Monte Carlo Methods, A. Lovato, N. Rocco, Rocco Schiavilla
Muon Capture In Nuclei: An Ab Initio Approach Based On Green's Function Monte Carlo Methods, A. Lovato, N. Rocco, Rocco Schiavilla
Physics Faculty Publications
An ab initio Green’s function Monte Carlo (GFMC) method is introduced for calculating total rates of muon weak capture in light nuclei with mass number A ≤ 12. As a first application of the method, we perform a calculation of the rate in 3H and 4He in a dynamical framework based on realistic two- and three-nucleon interactions and realistic nuclear charge-changing weak currents. The currents include one- and two-body terms induced by π-and ρ-meson exchange, and N-to-Δ excitation, and are constrained to reproduce the empirical value of the Gamow-Teller matrix element in tritium. We investigate the sensitivity of …
Structure Of Parton Quasi-Distributions And Their Moments, A. V. Radyushkin
Structure Of Parton Quasi-Distributions And Their Moments, A. V. Radyushkin
Physics Faculty Publications
We discuss the structure of the parton quasi-distributions (quasi-PDFs) Q (y, P-3) outside the "canonical" -1 <= y <= 1 support region of the usual parton distribution functions (PDFs). Writing the y(n) moments of Q (y, P-3) in terms of the combined x(n-2l)k(perpendicular to)(2l)-moments of the transverse momentum distribution (TMD). F(x,k(perpendicular to)(2)), we establish a connection between the large-vertical bar y vertical bar behavior of Q (y, P-3) and large-k(perpendicular to)(2) behavior of F(x,k(perpendicular to)(2)). In particular, we show that the 1/k(perpendicular to)(2) hard tail of TMDs in QCD results in a slowly decreasing similar to 1/vertical bar y vertical bar behavior of quasi-PDFs for large vertical bar y vertical bar that produces infinite y(n) moments of Q(y, P-3). We also relate the - 1/vertical bar y vertical bar terms with the lnz(3)(2)-singularities of the Ioffe-time pseudo-distributions m(v, z(3)(2)). Converting the operator product expansion for m(v,z(3)(2)) into a matching relation between the quasi-PDF Q(y, P-3) and the light-cone PDF f (x, mu(2)), we demonstrate that there is no contradiction between the infinite values of the y(n) moments of Q (y, P-3) and finite values of the x(n) moments of f (x, mu(2))
Form Factors Of Two-Hadron States From A Covariant Finite-Volume Formalism, Alessandro Baroni, Raúl Briceño, Maxwell T. Hansen, Felipe G. Ortega-Gama
Form Factors Of Two-Hadron States From A Covariant Finite-Volume Formalism, Alessandro Baroni, Raúl Briceño, Maxwell T. Hansen, Felipe G. Ortega-Gama
Physics Faculty Publications
In this work we develop a Lorentz-covariant version of the previously derived formalism for relating finite-volume matrix elements to 2 + J → 2 transition amplitudes. We also give various details relevant for the implementation of this formalism in a realistic numerical lattice QCD calculation. Particular focus is given to the role of single-particle form factors in disentangling finite-volume effects from the triangle diagram that arise when J couples to one of the two hadrons. This also leads to a new finite-volume function, denoted G, the numerical evaluation of which is described in detail. As an example we discuss …