Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Robert Wiringa Project Name: qmc_for_nuclei Division: PHY Project title: Quantum Monte Carlo Calculations of Light Nuclei Associated funding: DOE Division of Nuclear Physics Other Systems: ANL Blue Gene/P (INCITE 15M hours for 12C studies) ANL Blue Gene/Q (early user time for same) ANL SiCortex (indeterminate) Science: This project uses Quantum Monte Carlo [Green's function (GFMC), variational (VMC), and auxiliary-field diffusion (AFDMC)] methods to compute ground-state and low-lying excited-state expectation values of energies, densities, structure functions, astrophysical reaction rates, etc., for light nuclei and low-energy scattering reactions involving these nuclei. Realistic two- and three-nucleon potentials are used. Our goal is a description of all of these systems using a Hamiltonian that also provides an excellent description of nucleon-nucleon scattering and nucleonic matter. Such a `standard nuclear model' can then be used, for example, to compute low-energy astrophysical reactions which cannot be experimentally measured. We are also actively engaged in making predictions that can and are being tested at rare isotope beam facilities such as ATLAS, NSCL, and TRIUMF. Project description: A) Electroweak moments and transitions We are studying a variety of electroweak properties and transitions in light p-shell nuclei, including both one- and two-body charge and current operators that include the effect of meson-exchange currents. We are nearing completion of work on magnetic moment and M1 transitions in A=7-9 nuclei. We will extend these calculations to moments and M1 and M3 transitions in A=10 nuclei in FY13. We have also been studying E0 and E2 transitions in A=10 in co-operation with an experimental program at ATLAS, and finding they may provide new constraints on three-nucleon forces. We are just now starting work on longitudinal and transverse response functions, which have not previously been studied for A>7 nuclei. We expect to use 160,000 hours for this work in FY13. B) A=11,12 nuclei Extensive effort has gone into GFMC calculations of 12C using the BlueGene/P system, but only a few exploratory calculations of other A>10 nuclei have been made. We want to explore different possible trial functions for other cases like 11Li, 11B, and 12Be, particularly wave functions that are "clusterized." The VMC codes for these trial functions were made more efficient for large nuclei this year by adding OpenMP commands in addition to the existing MPI structure. We are also continuing studies of unnatural parity and intruder states in A=10 nuclei, where one or two nucleons are promoted from the p-shell to the sd-shell. A particularly interesting case is that of 1- states in 10B which exhibit significant isospin-mixing. We would like 80,000 cpu hours to this work in FY13 C) Asymptotic normalization coefficients and resonance widths for alpha-decay In the last two years we have developed a new method for evaluating asymptotic normalization coefficients (ANCs) that characterize the long-range tails of nuclear bound states and are the key determinant in low-energy astrophysics reaction rates. The calculation uses a short-range integral technique that can make do with relatively simple variational wave functions. A variant of this method allows the calculation of widths of narrow unbound states. The method has been applied to single-nucleon emission up to A=9 nuclei. In FY13 we plan to adapt the method for alpha-particle emission and study ANCs and widths nuclei up to A=10. We will need 40,000 hours for this work in FY13. D) Nucleon-nucleus scattering We are continuing our studies of nucleon-nucleus scattering for n+3H, p+3He, n+4He, and p+4He, and for parity-violating (PV) n+4He scattering. Our earlier n+4He studies were limited to scattering energies of 4 MeV or less. We have made some progress this year in developing better trial wave functions that can be used up to 20 MeV. We would also like to move to some heavier systems like n+8He scattering. We would like 40,000 cpu hours available for this work. Project URL: http://www.phy.anl.gov/theory/research/forces.html Current FY Hours Used: undetermined amount New FY Requested allocation: 320000 Q1: 80000 Q2: 80000 Q3: 80000 Q4: 80000 Justification: Thank You, The LCRC Accounts System