1,381,188 research outputs found

    Probing the EOS of dense neutron-rich matter with high-energy radioactive beams

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    Nuclear reactions induced by high energy radioactive beams create a transient state of nuclear matter with high density and appreciable neutron to proton asymmetry. This will provide a unique opportunity to explore novel properties of dense neutron-rich matter and the isospin-dependence of the nuclear equation of state (EOS). Here we study the π/π+\pi^-/\pi^+ ratio as a probe of the EOS of dense neutron-rich matter.Comment: Talk given at NN2003 to appear in the Proc. in Nucl. Phys. A (2004

    Generalized Adaptive Network Coding Aided Successive Relaying Based Noncoherent Cooperation

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    A generalized adaptive network coding (GANC) scheme is conceived for a multi-user, multi-relay scenario, where the multiple users transmit independent information streams to a common destination with the aid of multiple relays. The proposed GANC scheme is developed from adaptive network coded cooperation (ANCC), which aims for a high flexibility in order to: 1) allow arbitrary channel coding schemes to serve as the cross-layer network coding regime; 2) provide any arbitrary trade-off between the throughput and reliability by adjusting the ratio of the source nodes and the cooperating relay nodes. Furthermore, we incorporate the proposed GANC scheme in a novel successive relaying aided network (SRAN) in order to recover the typical 50% half-duplex relaying-induced throughput loss. However, it is unrealistic to expect that in addition to carrying out all the relaying functions, the relays could additionally estimate the source-to-relay channels. Hence noncoherent detection is employed in order to obviate the power-hungry channel estimation. Finally, we intrinsically amalgamate our GANC scheme with the joint network-channel coding (JNCC) concept into a powerful three-stage concatenated architecture relying on iterative detection, which is specifically designed for the destination node (DN). The proposed scheme is also capable of adapting to rapidly time-varying network topologies, while relying on energy-efficient detection

    Temperature dependence of thermal conductivities of coupled rotator lattice and the momentum diffusion in standard map

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    In contrary to other 1D momentum-conserving lattices such as the Fermi-Pasta-Ulam β\beta (FPU-β\beta) lattice, the 1D coupled rotator lattice is a notable exception which conserves total momentum while exhibits normal heat conduction behavior. The temperature behavior of the thermal conductivities of 1D coupled rotator lattice had been studied in previous works trying to reveal the underlying physical mechanism for normal heat conduction. However, two different temperature behaviors of thermal conductivities have been claimed for the same coupled rotator lattice. These different temperature behaviors also intrigue the debate whether there is a phase transition of thermal conductivities as the function of temperature. In this work, we will revisit the temperature dependent thermal conductivities for the 1D coupled rotator lattice. We find that the temperature dependence follows a power law behavior which is different with the previously found temperature behaviors. Our results also support the claim that there is no phase transition for 1D coupled rotator lattice. We also give some discussion about the similarity of diffusion behaviors between the 1D coupled rotator lattice and the single kicked rotator also called the Chirikov standard map.Comment: 6 pages, 5 figure

    Energy dependent kinetic freeze-out temperature and transverse flow velocity in high energy collisions

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    Transverse momentum spectra of negative and positive pions produced at mid-(pseudo)rapidity in inelastic or non-single-diffractive proton-proton collisions and in central nucleus-nucleus collisions over an energy range from a few GeV to above 10 TeV are analyzed by a (two-component) blast-wave model with Boltzmann-Gibbs statistics and with Tsallis statistics respectively. The model results are in similarly well agreement with the experimental data measured by a few productive collaborations who work at the Heavy Ion Synchrotron (SIS), Super Proton Synchrotron (SPS), Relativistic Heavy Ion Collider (RHIC), and Large Hadron Collider (LHC), respectively. The energy dependent kinetic freeze-out temperature and transverse flow velocity are obtained and analyzed. Both the quantities have quick increase from the SIS to SPS, and slight increase or approximate invariability from the top RHIC to LHC. Around the energy bridge from the SPS to RHIC, the considered quantities in proton-proton collisions obtained by the blast-wave model with Boltzmann-Gibbs statistics show more complex energy dependent behavior comparing with the results in other three cases.Comment: 16 pages, 4 figures. The European Physical Journal A, accepted. arXiv admin note: text overlap with arXiv:1805.0334

    Successive AF/DF Relaying in the Cooperative DS-CDMA Uplink: Capacity Analysis and its System Architecture

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    A successive relaying aided network (SRAN) is designed for a multi-user spread-spectrum scenario conceived for noncoherent (NC) detection in order to convert the typical 50% half-duplex relaying-induced throughput loss to a potential user-load reduction of the CDMA system, where the NC allows us to avoid the extra power consumption imposed by channel estimation. We commence by evaluating the noncoherent Discrete-input Continuous-output Memoryless Channel (DCMC) capacity of both the Amplify-and-Forward (AF) based and of the Decode-and-Forward (DF) based SRAN in the DS-CDMA uplink. Whilst NC detection has the added benefit of eliminating both the pilot-overhead and power-hungry channel estimation, it tends to form an error-floor at high Doppler frequencies. We mitigate this problem using multiple-symbol detection, which increases the detection complexity upon extending the detection window. Finally, a relay-aided soft-input soft-output Multiple-Symbol Differential Sphere Detection (SISO-MSDSD) CDMA regime is proposed, which significantly reduces the system’s complexity without sacrificing its performance
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