Quark mass dependence of nucleon mass and axial-vector coupling constant

We present an updated analysis of the quark mass dependence of the nucleon mass and nucleon axial-vector coupling g_A, comparing different formulations of SU(2) Baryon Chiral Effective Field Theory, with and without explicit delta (1232) degrees of freedom. We discuss the outcome of the corresponding interpolations between lattice QCD data and the physical values for these two nucleon observables. It turns out that in order to obtain successful interpolating functions at one-loop order, the inclusion of explicit delta (1232) degrees of freedom is not decisive for the nucleon mass but crucial for g_A. A chiral extrapolation of recent lattice results by the LHP collaborations is also shown.Comment: 5 pages, 7 figures, Talk given at the Workshop on Computational Hadron Physics, Nicosia, Cyprus, 14-17 September 200

Chiral Perturbation Theory and Finite Size Effects on the Nucleon Mass in unquenched QCD

We calculate finite size effects on nucleon masses in chiral perturbation theory. We confront the theoretical predictions with N_f=2 lattice results and discuss chiral extrapolation formulae.Comment: talk at Lattice 03 (spectrum), 3 pages latex, 3 figures. Assignment of 2 data points to incorrect data sets in plot 1 and of 1 data point in plot 2 corrected. 1 fm lattice result updated. Conclusions unchange

Chiral symmetry and the axial nucleon to Delta(1232) transition form factors

We study the momentum and the quark mass dependence of the axial nucleon to Delta(1232) transition form factors in the framework of non-relativistic chiral effective field theory to leading-one-loop order. The outcome of our analysis provides a theoretical guidance for chiral extrapolations of lattice QCD results with dynamical fermions.Comment: 18 pages, 3 figure

Quark Mass Dependence of Nucleon Properties and Extrapolation from Lattice QCD

We summarize developments concerning the quark mass dependence of nucleon magnetic moments and the axial-vector coupling constant g_A. The aim is to explore the feasibility of chiral effective field theory methods for the extrapolation of lattice QCD results, from the relatively large quark masses that can be handled in such computations down to the physically relevant range.Comment: 9 pages, Latex, 4ps figures, uses World Scientific style file; presented at International School ``Quarks in Hadrons and Nuclei'', Erice, Sicily, September 200

Nucleon Electromagnetic Form Factors from Lattice QCD using 2+1 Flavor Domain Wall Fermions on Fine Lattices and Chiral Perturbation Theory

We present a high-statistics calculation of nucleon electromagnetic form factors in $N_f=2+1$ lattice QCD using domain wall quarks on fine lattices, to attain a new level of precision in systematic and statistical errors. Our calculations use $32^3 \times 64$ lattices with lattice spacing a=0.084 fm for pion masses of 297, 355, and 403 MeV, and we perform an overdetermined analysis using on the order of 3600 to 7000 measurements to calculate nucleon electric and magnetic form factors up to $Q^2 \approx$ 1.05 GeV$^2$. Results are shown to be consistent with those obtained using valence domain wall quarks with improved staggered sea quarks, and using coarse domain wall lattices. We determine the isovector Dirac radius $r_1^v$, Pauli radius $r_2^v$ and anomalous magnetic moment $\kappa_v$. We also determine connected contributions to the corresponding isoscalar observables. We extrapolate these observables to the physical pion mass using two different formulations of two-flavor chiral effective field theory at one loop: the heavy baryon Small Scale Expansion (SSE) and covariant baryon chiral perturbation theory. The isovector results and the connected contributions to the isoscalar results are compared with experiment, and the need for calculations at smaller pion masses is discussed.Comment: 44 pages, 40 figure

Finite volume corrections to the electromagnetic current of the nucleon

We compute corrections to both the isovector anomalous magnetic moment and the isovector electromagnetic current of the nucleon to $O(p^3)$ in the framework of covariant two-flavor Baryon Chiral Perturbation Theory. We then apply these corrections to lattice data for the anomalous magnetic moment from the LHPC, RBC & UKQCD and QCDSF collaborations

Exploring gender impact on collaborative care planning: insights from a community mental health service study in Italy

INTRODUCTION: Personal recovery is associated with socio-demographic and clinical factors, and gender seems to influence the recovery process. This study aimed to investigate: i) differences in the recovery goals of men and women users of a community mental health service in Italy; ii) any differences by gender in recovery over six months using the Mental Health Recovery Star (MHRS). METHODS: Service users and staff completed the MHRS together at recruitment and six months later to agree the recovery goals they wished to focus on. Socio-demographic and clinical characteristics and ratings of symptoms (BPRS), needs (CAN), functioning (FPS), and functional autonomy (MPR) were collected at recruitment and six months follow-up. Comparisons between men and women were made using t-tests. RESULTS: Ten women and 15 men completed the MHRS with 19 mental health professionals. Other than gender, men and women had similar socio-demographic, and clinical characteristics at recruitment. Women tended to choose recovery goals that focused on relationships whereas men tended to focus on work related goals. At follow-up, both men and women showed improvement in their recovery (MHRS) and women were less likely to focus on relationship related goals, perhaps because some had found romantic partners. There were also gains for both men and women in engagement with work related activities. Ratings of functional autonomy (MPR) improved for both men and women, and men also showed improvement in symptoms (BPRS) and functioning (FPS). CONCLUSIONS: Our findings suggest that collaborative care planning tools such as the MHRS can assist in identifying individualized recovery goals for men and women with severe mental health problems as part of their rehabilitation

Nucleon mass and sigma term from lattice QCD with two light fermion flavors

We analyze Nf=2 nucleon mass data with respect to their dependence on the pion mass down to mpi = 157 MeV and compare it with predictions from covariant baryon chiral perturbation theory (BChPT). A novel feature of our approach is that we fit the nucleon mass data simultaneously with the directly obtained pion-nucleon sigma-term. Our lattice data below mpi = 435 MeV is well described by O(p^4) BChPT and we find sigma=37(8)(6) MeV for the sigma-term at the physical point. Using the nucleon mass to set the scale we obtain a Sommer parameter of r_0=0.501(10)(11) fm.Comment: 26 pages, 11 figures, 5 tables. Version to appear in NPB with a few more details on the fit parameter

Chiral extrapolation of g_A with explicit Delta(1232) degrees of freedom

An updated and extended analysis of the quark mass dependence of the nucleon's axial vector coupling constant g_A is presented in comparison with state-of-the-art lattice QCD results. Special emphasis is placed on the role of the Delta(1232) isobar. It is pointed out that standard chiral perturbation theory of the pion-nucleon system at order p^4 fails to provide an interpolation between the lattice data and the physical point. In constrast, a version of chiral effective field theory with explicit inclusion of the Delta(1232) proves to be successful. Detailed error analysis and convergence tests are performed. Integrating out the Delta(1232) as an explicit degree of freedom introduces uncontrolled errors for pion masses m_pi >~ 300 MeV.Comment: 25 pages, 12 figures, 2 tables; v2: minor change