Search results for "Rules"

Seniority rules, worker mobility and wages : evidence from multi-country linked employer-employee data

2018

We construct multi-country employer-employee data to examine the consequences of last-in, first-out rules. We identify the effects by comparing worker exit rates between different units of the same firms operating in Sweden and Finland, two countries that have different seniority rules. We observe a relatively lower exit rate for more senior workers in Sweden in the shrinking firms and among the low-wage workers. These empirical patterns are consistent with last-in, first-out rules in Sweden providing protection from dismissals for the more senior workers among the worker groups to whom the rules are most relevant. Similarly, we observe a steeper seniority-wage profile in Sweden, suggesting…

Identification of Distributed Systems with Logical Interaction Structure

2012

This paper focuses on the structure identification problem for a class of networked systems, where the interaction among components or agents is described through logical maps. In particular, agents are heterogeneous cooperating systems, i.e. they may have different individual dynamics and different interaction rules depending on input events. While we assume that the individual agents' dynamics are known, each agent has partial knowledge of the logical map encoding the interaction of another agent with its neighbors. Based on the so-called algebraic normal form for binary functions, we present a technique by which the network structure described by a logical function can be dynamically est…

Structure of pion photoproduction amplitudes

2018

We derive and apply the finite energy sum rules to pion photoproduction. We evaluate the low energy part of the sum rules using several state-of-the-art models. We show how the differences in the low energy side of the sum rules might originate from different quantum number assignments of baryon resonances. We interpret the observed features in the low energy side of the sum rules with the expectation from Regge theory. Finally, we present a model, in terms of a Regge-pole expansion, that matches the sum rules and the high-energy observables.

Two New Eudesmanolides from Artemisia caerulescens subsp. gargantae.

1990

Charm-quark mass from weighted finite energy QCD sum rules

2010

The running charm-quark mass in the scheme is determined from weighted finite energy QCD sum rules involving the vector current correlator. Only the short distance expansion of this correlator is used, together with integration kernels (weights) involving positive powers of s, the squared energy. The optimal kernels are found to be a simple pinched kernel and polynomials of the Legendre type. The former kernel reduces potential duality violations near the real axis in the complex s plane, and the latter allows us to extend the analysis to energy regions beyond the end point of the data. These kernels, together with the high energy expansion of the correlator, weigh the experimental and theo…

Pentaquark from QCD sum rules: consequences of the diquark approach

2006

In this work we investigate the consequences of the Jaffe and Wilczek diquark model in the framework of QCD sum rules. An analysis of the Theta^+(1540) as (ud)^2\bar{s} state shows that the mass of the pentaquark is compatible with the experimentally measured value. The mass difference between the Theta^+ and the pentaquark with the quantum numbers of the nucleon amounts to 70 MeV and is consistent with the interpretation of the N(1440) as a pentaquark.

Exploring the D* rho system within QCD sum rules

2013

We present a study of the D* rho system made by using the method of QCD sum rules to determine the mass of possible resonances generated in the same system. Using isospin and spin projectors, we investigate the different configurations and obtain evidences for three D* mesons with isospin I = 1/2, spin S = 0, 1, 2 and with masses 2500 +/- 67, 2523 +/- 60, and 2439 +/- 119 MeV, respectively. The last state can be associated with D-2*(2460) ( spin 2) listed by the Particle Data Group, while one of the first two might be related to D* (2640), with unknown spin parity. In the case of I = 3/2 we also find evidences of three states with spin 0, 1, and 2, respectively, with masses 2467 +/- 82, 242…

Radiative decay of the dynamically generated open and hidden charm scalar meson resonancesDs0*(2317)andX(3700)

2007

We present the formalism for the decay of dynamically generated scalar mesons with open- or hidden charm and give results for the decay of ${D}_{s0}^{*}(2317)$ to $\ensuremath{\gamma}{D}_{s}^{*}$ plus that of a hidden charm scalar meson state predicted by the theory around 3700 MeV decaying into $\ensuremath{\gamma}J/\ensuremath{\psi}$.

Duality violation in QCD Sum Rules with the LR correlator

2010

5 páginas, 4 figuras.-- Dedicated to the memory of our colleague and friend Joaquim (Ximo) Prades.-- Talk given at the 15th International QCD Conference (Montpellier, 28th June - 3rd July 2010) and the Internation Light Cone 2010 Conference (Valencia, 14-18th June 2010).-- arXiv:1010.1219v1.

Possible ω bound states in nuclei produced with the (γ,p) reaction

2007

We perform calculations for ω production in nuclei by means of the ( γ, p) reaction for photon energies and proton angles suited to currently running and future experiments in present laboratories. For some cases of possible ω optical potentials, we find that clear peaks are observable when a good resolution in the ω energy is available. We also study the inclusive production of π 0 γ in nuclei around the ω energy and find a double hump structure for the energy spectra, with a peak around a π 0 γ energy of mω − 100 MeV, which could easily be misidentified by a signal of an ω bound state in nuclei, while it is actually due to a different scaling of the uncorrelated π 0 γ production and ω pro…