Extracting the Strange Density from xF3xF_3

We present a QCD analysis of the strange and charm contributions to the neutrino deep inelastic structure function $xF_3$. We show that next-to-leading order effects, which are relatively important for $F_2$, play a lesser role in the case of $xF_3$. The neutrino--antineutrino difference $xF_3^{\nu} - xF_3^{\bar \nu}$ provides a new determination of the strange density, which exhibits some advantages with respect to other traditional methods.Comment: 12 page

Unitarization of Structure Functions at Large 1/x{\bf 1/x}

We discuss the effects of the $s$-channel unitarization on the $x$ and $Q^{2}$ dependence of structure functions. The unitarization is implemented at the level of photoabsorption cross sections by resorting to the light--cone wave functions of virtual photons and to the diagonalization property of the scattering matrix in a basis of Fock states of the photon with fixed transverse size. Triple pomeron effects are also explicitly taken into account. We find large unitarity corrections to the structure functions at $x < 10^{-2}$. The results are in very good agreement with the existing NMC and the preliminary HERA data.Comment: 12 page

Understanding transversity: present and future

I review the present state of knowledge concerning transversity distributions and related observables. In particular, I discuss the phenomenology of transverse asymmetries in e p\uparrow, p p\uparrow, p\uparrow p\uparrow and pbar \uparrow p\uparrow scattering, and the perspectives of ongoing and future research.Comment: 9 pages, 1 figure, plenary talk at SPIN 2004 (Trieste), to be published in the Proceeding

Arbitrages and Arrow-Debreu Prices

The goal of this work is to check that there are no arbitrage opportunities in the CBOE market for S&P500 options and to extract from these options’ quotes the state-price density consistent with the Merton model. The structure of the article is as follows: in Section 2 we examine the relations between arbitrages and Arrow-Debreu prices; in Section 3 we consider two models which seem to be consistent with the market prices of index options: the CEV model and the Merton model; finally, in Section 4 we estimate the state-price density consistent with the Merton-Geske model. Some conclusions follow.state-price density, index options, Merton-Geske model

Charged branes interactions via Kalb-Ramond field

Because of its versatility, the 2-form field has been employed to describe a multitude of scenarios that range from high energy to condensed matter physics. Pushing forward in this endeavor we study the interaction energy, intermediated by this kind of field, between branes in a variety of configurations. Also, the so-called Cremmer-Scherk-Kalb-Ramond model, which consists of the electromagnetic field coupled to the Kalb-Ramond gauge potential, is considered. It turns out that these models exhibit a much richer class of sources than usually thought, able to intermediate novel forms of interactions in different scenarios.Comment: 12 latex pages, more general result