Renormalized QCD-inspired model for the pion and mesons

We apply the subtraction method to an effective QCD-inspired model, which includes the Coulomb plus a zero-range hyperfine interactions, to define a renormalized Hamiltonian for mesons. The spectrum of the renormalized Hamiltonian agrees with the one obtained with a smeared hyperfine interaction. The masses of the low-lying pseudo scalar and vector mesons are reasonably described within the model.Comment: 5 pages, 3 figures, 5 references. To be published in Nucl. Phys. B (Proc. Suppl.) Talk presented at the Workshop "Light-cone Physics: Particles and Strings" at ECT* in Trento, Sep 3-11, 200

On helicity and spin on the light cone

Starting from a one-body front-form equation with Lepage-Brodsky spinors we show, with a fair amount of new technology, how an integral equation in standard momentum space with Bjorken-Drell spinors can be obtained. The integral equation decouples for singlets and triplets.Comment: LaTeX2e, 5 pages, 11 references. to be published in Nucl. Phys. B (Proc. Suppl.) Talk presented at the Workshop "Light-cone Physics: Particles and Strings" at ECT* in Trento, Sep 3-11, 200

On the form factor of physical mesons and their distribution function

This work addresses more to the technical rather than to the physical problem, how to calculate analytically the form factor $F(Q)$, the associated mean-square radius $$, and the distribution function $\Phi(x,Q^2)$ for a given light-cone wave function $\Psi_{q\bar q}(x,\vec k_{\perp})$ of the pion. They turn out to be functions of only one dimensionless parameter, which is the ratio of the constituent quark mass and an effective Bohr momentum which measures the width of the wave function in momentum space. Both parameters are subject to change in the future, when the presently used solution for the over simplified $\uparrow\downarrow$-model will be replaced by something better. Their relation to and agreement with experiment is discussed in detail. The procedure can be generalized also to other hadrons.Comment: 19 pages, 8 figures, 1 table, 22 references. Submitted to Nucl.Phys.

Renormalization of an effective model Hamiltonian by a counter term

An ill-defined integral equation for modeling the mass-spectrum of mesons is regulated with an additional but unphysical parameter. This parameter dependance is removed by renormalization. Illustrative graphical examples are given.Comment: 3 pages, 3 figures, 1 reference. to be published in Nucl. Phys. B (Proc. Suppl.) Talk presented at the Workshop "Light-cone Physics: Particles and Strings" at ECT* in Trento, Sep 3-11, 200

Market for 33 percent interest loans. Financial inclusion and microfinance in India.

Financial inclusion is the process of building viable institutions that provide financial services to those hitherto excluded. These may include savings, insurances, remittances, and credit. Microfinance became the most dominant method for achieving financial inclusion. However, different microfinance schools of thought recommend opposite ways for attaining financial integration. India is a particularly insightful case study due to the sheer number of people excluded from formal financial services, as well as the spectrum of actors and approaches. The aim of this article is threefold. First, defining financial inclusion, depicting its status quo in India and comparing it to its South Asian and BRICS peers using recently released data from the Global Findex database. Second, focusing on microfinance as the dominant vehicle for achieving financial inclusion by scrutinizing its definitions, contrasting its two leading "schools of thought" and analyzing the central role of its dominant group-based approach. Third, the article will examine why people opt to take micro-credit at 33 percent interest rates

On the effective light-cone QCD-Hamiltonian: Application to the pion and other mesons

The effective interaction between a quark and an anti-quark as obtained previously with by the method of iterated resolvents is replaced by the up-down-model and applied to flavor off-diagonal mesons including the positive pion. The only free parameters are the canonical ones, the coupling constant and the masses of the quarks.Comment: 11 pages, 4 figures, 2 tables, 22 reference

On confinement in a light-cone Hamiltonian for QCD

The canonical front form Hamiltonian for non-Abelian SU(N) gauge theory in 3+1 dimensions and in the light-cone gauge is mapped non-perturbatively on an effective Hamiltonian which acts only in the Fock space of a quark and an antiquark. Emphasis is put on the many-body aspects of gauge field theory, and it is shown explicitly how the higher Fock-space amplitudes can be retrieved self-consistently from solutions in the $q\bar q$-space. The approach is based on the novel method of iterated resolvents and on discretized light-cone quantization driven to the continuum limit. It is free of the usual perturbative Tamm-Dancoff truncations in particle number and coupling constant and respects all symmetries of the Lagrangian including covariance and gauge invariance. Approximations are done to the non-truncated formalism. Together with vertex as opposed to Fock-space regularization, the method allows to apply the renormalization programme non-perturbatively to a Hamiltonian. The conventional QCD scale is found arising from regulating the transversal momenta. It conspires with additional mass scales to produce possibly confinement.Comment: 15 pages, LaTeX2e, macro svjour included in uu-file 5 figures, ps-files included in uu-fil