Event-by-Event Jet Quenching

High momentum jets and hadrons can be used as probes for the quark gluon plasma (QGP) formed in nuclear collisions at high energies. We investigate the influence of fluctuations in the fireball on jet quenching observables by comparing propagation of light quarks and gluons through averaged, smooth QGP fireballs with event-by-event jet quenching using realistic inhomogeneous fireballs. We find that the transverse momentum and impact parameter dependence of the nuclear modification factor R_AA can be fit well in an event-by-event quenching scenario within experimental errors. However the transport coefficient qhat extracted from fits to the measured nuclear modification factor R_AA in averaged fireballs underestimates the value from event-by-event calculations by up to 50%. On the other hand, after adjusting qhat to fit R_AA in the event-by-event analysis we find residual deviations in the azimuthal asymmetry v_2 and in two-particle correlations, that provide a possible faint signature for a spatial tomography of the fireball.Comment: 8 pages, 5 figures; v2: new figure added, small changes and fixes, this version published in Phys. Lett.

E-commerce and territorial development in the Objective-1 spanish regions

The information and communication technologies constitute one of the main forces of the globalization. In this framework, the e-commerce takes advantage of Internet to improve the competitiveness of the companies and territories. In the nowadays scenario, the e-commerce opens development posibilities for the regions fewer developed, creating a virtual space that saves the geographical barriers. However, the use of its advantages requires infrastructures and equipment, organizational capacity and high formation in new technologies. In spite of the deficit that the objetive 1 spanish regions show in these fields to develop the their own Information Society, the attitude and the efforts of the public and private agents in improving their position in the national and international context, they open optimistic expectations on the future use of the advantages that the e-commerce offers for the growth and the improvement of the regional competitiveness in Spain. Nevertheless, one cannot hope the e-commerce is a decisive element to eliminate the territorial inequalities, not even the technologies of the information in its group, but rather it can be that they originate a restructuring of the spanish and european territorial pattern, where some regions will be able to improve thanks to the extension and deeping of the digital economy and others will worsen its position in the territorial system. In any event, the developed regions leave of a better position. All the analysts coincide in pointing out that the e-commerce is in an incipient phase, for what es expected that its growth in next years is very important. In this sense, this communication seeks to analyze the use of the possibilities that the e-commerce offers as tool of improvement of the competitiveness in the objetive 1 spanish regions in the framework of the regional development. To get this objetive, the theoretical linkings are revised among the new information and communication technologies, that allow the use of Internet like a trade channel, and the territorial development, showing the different focuses with those that are come approaching the influences of the Information Society on the regional competitiveness. Also, the current situation and perspectives of the objetive one spanish regions are rewied to face the challenges that outline the technological advances in this field in three environments: infrastructures and equipment; organization, support institutions and administration initiatives; and innovation, knowledge and formation.

Approximate Quantum Adders with Genetic Algorithms: An IBM Quantum Experience

It has been proven that quantum adders are forbidden by the laws of quantum mechanics. We analyze theoretical proposals for the implementation of approximate quantum adders and optimize them by means of genetic algorithms, improving previous protocols in terms of efficiency and fidelity. Furthermore, we experimentally realize a suitable approximate quantum adder with the cloud quantum computing facilities provided by IBM Quantum Experience. The development of approximate quantum adders enhances the toolbox of quantum information protocols, paving the way for novel applications in quantum technologies

Digital-Analog Quantum Simulations with Superconducting Circuits

Quantum simulations consist in the intentional reproduction of physical or unphysical models into another more controllable quantum system. Beyond establishing communication vessels between unconnected fields, they promise to solve complex problems which may be considered as intractable for classical computers. From a historic perspective, two independent approaches have been pursued, namely, digital and analog quantum simulations. The former usually provide universality and flexibility, while the latter allows for better scalability. Here, we review recent literature merging both paradigms in the context of superconducting circuits, yielding: digital-analog quantum simulations. In this manner, we aim at getting the best of both approaches in the most advanced quantum platform involving superconducting qubits and microwave transmission lines. The discussed merge of quantum simulation concepts, digital and analog, may open the possibility in the near future for outperforming classical computers in relevant problems, enabling the reach of a quantum advantage.Comment: Review article, 26 pages, 4 figure

Response of soybean stem termination types to water stress and supplemental irrigation

This dissertation reports two investigations. One was conducted at Ames, Iowa, during 1980 and 1981, with the aim of evaluating the response of soybean Glycine max (L.) Merr. stem termination types (indeterminate, semideterminate, determinate) to supplemental irrigation during seed growth. The second was done in Costa Rica from February to May (field) and from August to November (glasshouse), 1982. The objective of the second study was to evaluate the response of water stress of tropical determinate and indeterminate soybean cultivars. Because of their ability to continue growth during early reproduction, indeterminates should recover from stress better and respond better to irrigation;The nonirrigated Iowa soybean crop had lower predawn and midday water potentials during seed filling and significantly lower yield than the irrigated soybean crop. However, there was no difference in response of the stem termination types to supplemental irrigation. Average yield response to irrigation was 16.4%. Seed yield increase in response to irrigation of determinates and semideterminates was mostly due to increased number of pods per node, whereas, with indeterminates, it resulted partly from increased pods per node and partly from increased nodes. Indeterminates grew more and lodged more under irrigation than did semideterminates; the determinate types did not lodge at all;The study conducted in Costa Rica showed that field-grown soybean plants under stress had predawn water potentials within -0.1 to -0.2 MPa of well-watered controls after water had been withheld one week. Stomata showed the greatest decrement in water vapor conductance at water potentials between -1.3 and -1.4 MPa. Under moderate to severe stress, stomata on the adaxial surface completely closed early in the drying cycle;Indeterminate cultivars were better able to recover from water stress than were determinate ones, as indicated by better seed yield under field conditions. This response was associated with the number of pods per node rather than with other basic yield components, or with leaf area index or leaf area duration;Environmental conditions in the glasshouse induced determinateness in the indeterminate cultivar; consequently, it responded to water stress the same as the determinate cultivar

The magnetic fields of starburst galaxies. I. Identification and characterization of the thermal polarization in the galactic disk and outflow

Far-infrared polarized emission by means of magnetically aligned dust grains is an excellent tracer of the magnetic fields (B-fields) in the cold phase of the galactic outflows in starburst galaxies. We present a comprehensive study of the B-fields in three nearby ($3.5$-$17.2$ Mpc) starbursts (M82, NGC 253, and NGC 2146) at $5$ pc-$1.5$ kpc resolutions using publicly available $53$-$890$ $\mu$m imaging polarimetric observations with SOFIA/HAWC+, JCMT/POL-2, and ALMA. We find that the polarized spectral energy distributions (SEDs) of the full galaxies are dominated by the polarized SEDs of the outflows with dust temperatures of $T_{\rm{d,outflow}}^{\rm{PI}}\sim45$ K and emissive index of $\beta_{\rm{outflow}}^{\rm{PI}}\sim2.3$. The disks are characterized by low $T_{\rm{d,disk}}^{\rm{PI}}=[24,31]$ K and $\beta_{\rm{disk}}^{\rm{PI}}\sim1$. We show that disk- and outflow-dominated galaxies can be better distinguished by using polarized SEDs instead of total SEDs. We compute the $53$-$850$ $\mu$m polarization spectrum of the disk and outflow and find that dust models of the diffuse ISM can reproduce the fairly constant polarization spectrum of the disk, $\langle P_{\rm{disk}} \rangle=1.2\pm0.5$%. The dust models of heterogenous clouds and two temperature components are required to explain the polarization spectrum of the outflow ($2$-$4$% at $53$ $\mu$m, $\sim1$% at $850$ $\mu$m, and a minimum within $89$-$154$ $\mu$m). We conclude that the polarized dust grains in the outflow arise from a dust population with higher dust temperature and emissivities than those from the total flux. The B-fields of the outflows have maximum extensions within $89$-$214$ $\mu$m reaching heights of $\sim4$ kpc, and flatter polarized fluxes than total fluxes. The extension of the B-field permeating the circumgalactic medium increases with increasing the star formation rate.Comment: 21 pages, 14 figures, 4 tables. Submitted to ApJ with positive review by the anonymous referee. Comments are welcom