Density-functional theory for fermions in the unitary regime

In the unitary regime, fermions interact strongly via two-body potentials that exhibit a zero range and a (negative) infinite scattering length. The energy density is proportional to the free Fermi gas with a proportionality constant $\xi$. We use a simple density functional parametrized by an effective mass and the universal constant $\xi$, and employ Kohn-Sham density-functional theory to obtain the parameters from fit to one exactly solvable two-body problem. This yields $\xi=0.42$ and a rather large effective mass. Our approach is checked by similar Kohn-Sham calculations for the exactly solvable Calogero model.Comment: 5 pages, 2 figure

Octet Baryon Charge Radii, Chiral Symmetry and Decuplet Intermediate States

We compute the octet baryon charge radii to O(1/Heavy^3) in heavy baryon chiral perturbation theory. We examine the effect of including the decuplet of spin-3/2 baryons explicitly. We find that it does no t improve the level of agreement between the HBchiPT and experimental values for the Sigma^- charge radius.Comment: 9 pages, 2 figures. Uses axodraw.sty, include

Subleading corrections to parity-violating pion photoproduction

We compute the photon asymmetry Bγ for near threshold parity-violating (PV) pion photoproduction through subleading order. We show that subleading contributions involve a new combination of PV couplings not included in previous analyses of hadronic PV. We argue that existing constraints on the leading order contribution to Bγ—obtained from the PV γ-decay of 18F—suggest that the impact of the subleading contributions may be more significant than expected from naturalness arguments

Chiral Symmetry and the Parity-Violating NNπNN\pi Yukawa Coupling

We construct the complete SU(2) parity-violating (PV) $\pi, N, \Delta$ interaction Lagrangian with one derivative, and calculate the chiral corrections to the PV Yukawa $NN\pi$ coupling constant $h_\pi$ through ${\cal O}(1/\Lambda_\chi^3)$ in the leading order of heavy baryon expansion. We discuss the relationship between the renormalized \hpi, the measured value of \hpi, and the corresponding quantity calculated microscopically from the Standard Model four-quark PV interaction.Comment: RevTex, 26 pages + 5 PS figure

Anomalous Chiral Action from the Path-Integral

By generalizing the Fujikawa approach, we show in the path-integral formalism: (1) how the infinitesimal variation of the fermion measure can be integrated to obtain the full anomalous chiral action; (2) how the action derived in this way can be identified as the Chern-Simons term in five dimensions, if the anomaly is consistent; (3) how the regularization can be carried out, so as to lead to the consistent anomaly and not to the covariant anomaly. Our method uses Schwinger's ``proper-time'' representation of the Green's function and the gauge invariant point-splitting technique. We find that the consistency requirement and the point-splitting technique allow both an anomalous and a non-anomalous action. In the end, the nature of the vacuum determines whether we have an anomalous theory, or, a non-anomalous theoryComment: 28 page

Recoil Order Chiral Corrections to Baryon Octet Axial Currents

We calculate chiral corrections to the octet axial currents through ${\cal O}(p^3)$ using baryon chiral perturbation theory (BCPT). The relativistic BCPT framework allows one to sum an infinite series of recoil corrections at a given order in the chiral expansion. We also include SU(3)-breaking operators occuring at ${\cal O}(p^2)$ not previously considered. We determine the corresponding low-energy constants (LEC's) from hyperon semileptonic decay data using a variety of infrared regularization schemes. We find that the chiral expansion of the axial currents does not display the proper convergence behavior, regardless of which scheme is chosen. We explore the implications of our analysis for determinations of the strange quark contribution to the nucleon spin, $\Delta s$.Comment: RevTex, 19 pages + 2 PS figure

Energy cost and parmesan cheese. An overview in the different energy fluxes needed to produce a parmesan wheel

Agriculture is responsible for up to 30% of the greenhouse gases emission, and cattle breeding is the main contributor making up almost 10% of the total. For this reason, this sector is a key player toward a complete decarbonization. To take the proper action to reduce climate impact of cattle breeding, it is necessary to know the energy requirements of the industry. This work focuses on the energy mapping of a parmesan cheese production, with reference to an agricultural company situated in Modena province with about six hundred animals. Knowing the electrical and thermal energy requirements to produce a wheel of cheese gives the possibility to the farmers to identify and reduce the energy wastage as well as starting the implementation of a strategy for fossil fuel substitution. In this study, a comprehensive monitoring campaign is presented together with the proposal of some possible improvements. The analysis showed that, considering the actual situation, about 64 kWh of electrical energy and 94 kWh of thermal energy are needed to produce a parmesan cheese wheel, while the fuel used to feed the agricultural machinery (e.g., tractors) accounts for around 174 kWh. In this context, the implementation of biogas and solar photovoltaic can greatly contribute to reduce the dependence on fossil fuels

Density Functional Theory: Methods and Problems

The application of density functional theory to nuclear structure is discussed, highlighting the current status of the effective action approach using effective field theory, and outlining future challenges.Comment: 10 pages, 14 figures, invited talk at INT workshop on Nuclear Forces and the Quantum Many-Body Problem, Seattle, October 200