Second Order Perturbation Theory for Improved Gluon and Staggered Quark Actions

We present the results of our perturbative calculations of the static quark potential, small Wilson loops, the static quark self energy, and the mean link in Landau gauge. These calculations are done for the one loop Symanzik improved gluon action, and the improved staggered quark action.Comment: 3 pages, LaTeX, Lattice2001(improvement

The Anchorage, Alaska Municipal Pretrial Diversion Program: An Initial Assessment

Pretrial diversion programs have the potential to prevent future criminal behavior through intervention and community based services. This may be particularly true for specific populations of offenders such as those with mental illness, substance abuse disorder, and those with co-occuring disorders. Pretrial diversion programs take low-level offenders out of the jail population, both reducing system overpopulation and costs of incarceration. The programs also provide speedy case processing for minor crimes resulting in savings to the court system and personnel. Pretrial diversion can help an offender avoid a criminal conviction and potentially avoid future criminal violations. Results indicate that most Anchorage pretrial defendants comply with and complete the pretrial conditions in a very short time period, an additional savings in case processing time. This research details the initial assessment of the Anchorage Municipal Prosecutor Pretrial Diversion program. This assessment examines system savings in time and money, as well as policy implications for the justice system that may assist other jurisdictions as they consider implementing a pretrial diversion program

The Anchorage, Alaska Municipal Pretrial Diversion Program: Initial Outcome Assessment

This report provides an initial outcome assessment of the Anchorage Municipal Pretrial Diversion Program, a voluntary program aimed at diverting first-time offenders in certain criminal and traffic cases from traditional case processing, with successful complion of the terms of the program resulting in dismissal of charges. Pretrial diversion agreements under AMC 08.05.060 typically require the defendant to pay a fine or do community work service, usually within a month. The initial assessment examines offender completion under the program, adherence to conditions of probation, and time and cost savings for the Anchorage Municipal Prosecutor's Office.Office of the Anchorage Municipal Prosecutor, Municipality of Anchorage, AKAcknowledgments / Section I: Executive Summary / Counts and Charges of Defendants Offered Pretrial Diversion / Demographic Variations Among Defendants Offered Pretrial Diversion / Conditions of Pretrial Diversion / Length of Time for Pretrial Diversion Processes / Number of Court Hearings and Estimated Time Spent / Section II: Introduction / Section III: Literature Review / Descriptions of Pretrial Diversion / Pretrial Diversion in the United States / Description of Pretrial Diversion in Anchorage / Section IV: Methods / Data Collection / Section VI: Findings / Counts and Charges of Defendants Offered Pretrial Diversion / Demographic Variations Among Defendants Offered Pretrial Diversion / Conditions of Pretrial Diversion / Length of Time for Pretrial Diversion Processes / Number of Court Hearings and Estimated Time Spent / Section VII: Conclusion / References / Appendix: Anchorage Municipal Pretrial Diversion Data Collection For

Improvement, dynamical fermions, and heavy quark screening in QCD_3

First results from simulations of improved actions for both gauge fields and staggered fermion fields in three dimensional QCD are presented. This work provides insight into some issues of relevance to lattice theories in four dimensions. In particular, the renormalization of the bare lattice coupling is dramatically reduced when the tree-level $O(a^2)$ improved action is used. Naik improvement of the staggered fermion action produces little reduction in scaling violations of the rho meson mass. String breaking in the heavy quark potential in the unquenched theory is also clearly resolved, using Wilson loops to bound the ground state energy.Comment: LATTICE98(improvement), 3 pages, 3 figures (psfig format

Mean link versus average plaquette tadpoles in lattice NRQCD

We compare mean-link and average plaquette tadpole renormalization schemes in the context of the quarkonium hyperfine splittings in lattice NRQCD. Simulations are done for the three quarkonium systems $c\bar c$, $b\bar c$, and $b\bar b$. The hyperfine splittings are computed both at leading and at next-to-leading order in the relativistic expansion. Results are obtained at a large number of lattice spacings. A number of features emerge, all of which favor tadpole renormalization using mean links. This includes much better scaling of the hyperfine splittings in the three quarkonium systems. We also find that relativistic corrections to the spin splittings are smaller with mean-link tadpoles, particularly for the $c\bar c$ and $b\bar c$ systems. We also see signs of a breakdown in the NRQCD expansion when the bare quark mass falls below about one in lattice units (with the bare quark masses turning out to be much larger with mean-link tadpoles).Comment: LATTICE(heavyqk) 3 pages, 2 figure

Highly Improved Naive and Staggered Fermions

We present a new action for highly improved staggered fermions. We show that perturbative calculations for the new action are well-behaved where those of the conventional staggered action are badly behaved. We discuss the effects of the new terms in controlling flavor mixing, and discuss the design of operators for the action.Comment: Contribution to Lattice2001(improvement); 3 page

Irreducible Multiplets of Three-Quark Operators on the Lattice: Controlling Mixing under Renormalization

High luminosity accelerators have greatly increased the interest in semi-exclusive and exclusive reactions involving nucleons. The relevant theoretical information is contained in the nucleon wavefunction and can be parametrized by moments of the nucleon distribution amplitudes, which in turn are linked to matrix elements of three-quark operators. These can be calculated from first principles in lattice QCD. However, on the lattice the problems of operator mixing under renormalization are rather involved. In a systematic approach we investigate this issue in depth. Using the spinorial symmetry group of the hypercubic lattice we derive irreducibly transforming three-quark operators, which allow us to control the mixing pattern.Comment: 13 page

Perturbative coefficients for improved actions by Monte Carlo at large β\beta

Perturbative estimates of operator coefficients for improved lattice actions are becoming increasingly important for precision simulations of many hadronic observables. Following previous work by Dimm, Lepage, and Mackenzie, we consider the feasibility of computing operator coefficients from numerical simulations deep in the perturbative region of lattice theories. Here we introduce a background field technique that may allow for the computation of the coefficients of clover-field operators in a variety of theories. This method is tested by calculations of the renormalized quark mass in lattice NRQCD, and of the $O(\alpha_s)$ clover coefficient for Sheikholeslami-Wohlert fermions. First results for the coefficient of the magnetic moment operator in NRQCD are also presented.Comment: 3 Pages, LaTeX (espcrc2.sty, uses \psfig), 3 Postscript figures, Talk presented at LATTICE'97, Edinburg

Subtractive renormalization of the NN interaction in chiral effective theory up to next-to-next-to-leading order: S waves

We extend our subtractive-renormalization method in order to evaluate the 1S0 and 3S1-3D1 NN scattering phase shifts up to next-to-next-to-leading order (NNLO) in chiral effective theory. We show that, if energy-dependent contact terms are employed in the NN potential, the 1S0 phase shift can be obtained by carrying out two subtractions on the Lippmann-Schwinger equation. These subtractions use knowledge of the the scattering length and the 1S0 phase shift at a specific energy to eliminate the low-energy constants in the contact interaction from the scattering equation. For the J=1 coupled channel, a similar renormalization can be achieved by three subtractions that employ knowledge of the 3S1 scattering length, the 3S1 phase shift at a specific energy and the 3S1-3D1 generalized scattering length. In both channels a similar method can be applied to a potential with momentum-dependent contact terms, except that in that case one of the subtractions must be replaced by a fit to one piece of experimental data. This method allows the use of arbitrarily high cutoffs in the Lippmann-Schwinger equation. We examine the NNLO S-wave phase shifts for cutoffs as large as 5 GeV and show that the presence of linear energy dependence in the NN potential creates spurious poles in the scattering amplitude. In consequence the results are in conflict with empirical data over appreciable portions of the considered cutoff range. We also identify problems with the use of cutoffs greater than 1 GeV when momentum-dependent contact interactions are employed. These problems are ameliorated, but not eliminated, by the use of spectral-function regularization for the two-pion exchange part of the NN potentialComment: 40 pages, 21 figure