One of the primary interests in investigating η meson-production reactions is that they may be suited to extract information on nucleon resonances, N, in the less-explored higher N mass region. Current knowledge of most of the nucleon resonances is mainly due to the study of πN scattering and/or pion photoproduction off the nucleon. Since the η meson is much heavier than a pion, η meson-product...

Abstract. The NA49 experiment at CERN SPS has acquired a huge data set of Pb+Pb events over a broad range of energy and centrality during the last several years. This high statistics data set, coupled with a state-of-the-art analysis technique, allows for the first model-independent extraction and energy scan of 3D emission sources for pion pairs at SPS energies. These 3D pion emission sources ...

Inclusive cross sections for pion production in proton-proton collisions are calculated for the first time based on unintegrated parton (gluon, quark, antiquark) distributions (uPDF). We use Kwieci´nski uPDF's and phenomenological fragmentation functions from the literature. In addition to the gg → g diagram used recently for applications at RHIC we include also gq → q and qg → q diagrams. We f...

We have performed a many body calculation of the inclusive (e, e′) cross section which runs over the three traditional regions at intermediate energies: the quasielastic peak, the dip region and the delta region. The longitudinal and transverse response functions in the quasielastic peak have also been evaluated. Traditional effects like polarization, meson exchange currents, final state intera...

In this paper 1 we stress the idea that new, more precise neutrino cross-sections measurements at low energies will be necessary to improve the results of future big neutrino detectors, which will be dominated by the contribution of the systematic errors. The use of a muon beam instead of the traditional pion beams is proposed. This choice allows the simultaneous measurement of both, νμ and νe ...

A description of low-energy scattering of pions and nuclei within a BUU transport model is presented. Implementing different scenarios of medium modifications, the mean free path of pions in nuclear matter at low momenta and pion absorption reactions on nuclei have been studied and compared to data and to results obtained via quantum mechanical scattering theory. We show that even in a regime o...

An analysis of incoherent photoproduction of η mesons off the deuteron for photon energies from threshold to 800 MeV is presented. The dominant contribution , the γN-ηN amplitude, is described within an isobar model. Effects of the final state interactions in the N N as well as the ηN systems are included employing models derived within the meson-exchange approach. It is found that their consid...

The effective chiral Lagrangian of the strong and electromagnetic interactions of the pseudoscalar mesons at low energies depends on a set of low energy constants. We determine the contributions to the electromagnetic coupling constants at order O(ep), which arise from resonances within a photon loop. We give some implications of our results, in particular we discuss in detail the effects on th...

The elastic charge form factors of the pion, kaon, Dand B-mesons are calculated within a relativistic constituent quark model formulated on the light-cone. Our parameter free predictions agree well with the available data. The results are approximately independent of the assumed form of the lightcone wave function, in particular they do not depend on the high momentum tail of the wave function ...

The prominent feature of the η meson is that it couples dominantly to the N(1535) (S11) resonance at threshold energies. The low-momentum η meson would then mainly excite N–nucleon-hole (N-h) states in nuclear matter. Therefore the η meson nuclear dynamics is sensitive to modifications of nucleon and N properties in medium. If some medium effects and/or a density increase bring the N-h state do...