Further Evidence of Narrow Baryonic Structures with Hadronic as Well as Leptonic Probes

Although extracted from several experiments using hadronic probes \cite{bor1}, narrow baryonic structures have been sometimes met with disbelief. New signatures are presented, which appear from already published data, obtained with hadronic probes as well as with leptonic probes. The authors of these results did not take into account the possibility to associate the discontinuities of their spectra with the topic of narrow baryonic low mass structures. The stability of the observed narrow structure masses, represents a confirmation of their genuine existence.Comment: 6 pages, 8 figures. Contribution XVII International Seminar on High Energy Physics Problems, Relativistic Nuclear Physics and Quantum Chromodynamics, Dubna, (Russia) Sept. 27- Oct 2, 200

Exotic low mass narrow baryons extracted from charge exchange reactions

This paper aims to give further evidence for the existence of low mass exotic baryons. Narrow structures in baryonic missing mass or baryonic invariant mass were observed during the last twelve years. Since their evidence is still under debate, various data, measured with incident hadrons, by different collaborations, are reanalyzed to bring evidence on these narrow exotic baryonic resonances excited in charge-exchange reactions. These structures are clearly exotic as there is no room for them in the $qqq$ configurations: their width is smaller than the widths of "classical" baryonic resonances, moreover some of the masses lie below the pion threshold mass.Comment: 21 pages, 27 figure

Intermediaries in International Trade: Direct versus indirect modes of export

This paper examines the factors that give rise to intermediaries in exporting and explores the implications for trade volumes. Export intermediaries such as wholesalers serve different markets and export different products than manufacturing exporters. In particular, high market-specific fixed costs of exporting, the (lack of) quality of the general contracting environment and product-specific factors play important roles in explaining the existence of export intermediaries. These underlying differences between direct and intermediary exporters have important consequences for trade flows. The ability of export intermediaries to overcome country and product fixed costs means that they can more easily respond along the extensive margin to external shocks. Intermediaries and direct exporters respond differently to exchange rate fluctuations both in terms of the total value of shipments and the number of products exported as well as in terms of prices and quantities. Aggregate exports to destinations with high shares of indirect exports are much less responsive to changes in the real exchange rate than are exports to countries served primarily by direct exporters.

Intermediaries in International Trade: direct versus indirect modes of export

This paper contributes to the relatively new literature on the role of intermediaries in international trade. Using Italian firm-level data, we document significant differences between exporters of different types and highlight the role of country-specific fixed cost in the choice of direct versus indirect modes of export. Recent theoretical work suggests that intermediaries are typically providing solutions to country-specific fixed costs. Our empirical results largely confirm this relationship. Measures of country fixed costs are positively associated with intermediary exports both in the aggregate and within firms. In contrast, proxies for variable trade costs are largely not correlated with differences between direct and indirect exports.heterogeneous firms, international trade, intermediation, wholesalers

Intermediaries in international trade : Direct versus indirect modes of export

This paper contributes to the relatively new literature on the role of intermediaries in international trade. Using Italian firm-level data, we document significant differences between exporters of different types and highlight the role of country-specific fixed cost in the choice of direct versus indirect modes of export. Recent theoretical work suggests that intermediaries are typically providing solutions to country-specific fixed costs. Our empirical results largely confirm this relationship. Measures of country fixed costs are positively associated with intermediary exports both in the aggregate and within firms. In contrast, proxies for variable trade costs are largely not correlated with differences between direct and indirect exports.

Intermediaries in International Trade: direct versus indirect modes of export

This paper contributes to the relatively new literature on the role of intermediaries in international trade. Using Italian firm-level data, we document significant differences between exporters of different types and highlight the role of country-specific fixed cost in the choice of direct versus indirect modes of export. Recent theoretical work suggests that intermediaries are typically providing solutions to country-specific fixed costs. Our empirical results largely confirm this relationship. Measures of country fixed costs are positively associated with intermediary exports both in the aggregate and within firms. In contrast, proxies for variable trade costs are largely not correlated with differences between direct and indirect exports.heterogeneous firms, international trade, intermediation, wholesalers

Millimeter and sub-millimeter atmospheric performance at Dome C combining radiosoundings and ATM synthetic spectra

The reliability of astronomical observations at millimeter and sub-millimeter wavelengths closely depends on a low vertical content of water vapor as well as on high atmospheric emission stability. Although Concordia station at Dome C (Antarctica) enjoys good observing conditions in this atmospheric spectral windows, as shown by preliminary site-testing campaigns at different bands and in, not always, time overlapped periods, a dedicated instrument able to continuously determine atmospheric performance for a wide spectral range is not yet planned. In the absence of such measurements, in this paper we suggest a semi-empirical approach to perform an analysis of atmospheric transmission and emission at Dome C to compare the performance for 7 photometric bands ranging from 100 GHz to 2 THz. Radiosoundings data provided by the Routine Meteorological Observations (RMO) Research Project at Concordia station are corrected by temperature and humidity errors and dry biases and then employed to feed ATM (Atmospheric Transmission at Microwaves) code to generate synthetic spectra in the wide spectral range from 100 GHz to 2 THz. To quantify the atmospheric contribution in millimeter and sub-millimeter observations we are considering several photometric bands in which atmospheric quantities are integrated. The observational capabilities of this site at all the selected spectral bands are analyzed considering monthly averaged transmissions joined to the corresponding fluctuations. Transmission and pwv statistics at Dome C derived by our semi-empirical approach are consistent with previous works. It is evident the decreasing of the performance at high frequencies. We propose to introduce a new parameter to compare the quality of a site at different spectral bands, in terms of high transmission and emission stability, the Site Photometric Quality Factor.Comment: accepted to MNRAS with minor revision

Charge exchange reactions on baryons and exotic low-mass narrow baryons.

Narrow structures in baryonic missing mass or baryonic invariant mass were observed during the last ten years. Since their existence remains controversial, previously published data, measured with incident hadrons, are reanalyzed to add new pieces of information. This contribution gives further evidence to the existence of low mass exotic baryons, excited in charge-exchange reaction

Additional Evidence for Low Mass Exotic Baryons

This paper aims to give further evidence for the existence of low mass exotic baryons. It consists of two parts: - first it recalls some results, already shown or even previously published, which reflect the existence of narrow low mass baryonic states, - then it presents new results obtained through the analysis of recent data from JLAB. We will show that these results are compatible with our previous observation, namely that the broad PDG baryonic resonances can be shared into several more narrow ones