177,835 research outputs found
Production of strange particles at intermediate pT at RHIC
The recombination model is applied to the production of
and at all in central Au+Au collisions. The thermal-shower
component of the recombination is found to be important for and ,
but only in a minor way for and in the intermediate to high
region. The normalization and inverse slope of the thermal partons in the
strange sector are determined by fitting the low- data. At higher
the data of and in the log scale are all well
reproduced in our study that extends the thermal contribution and includes the
shower contribution. The calculated result on the ratio rises to a
maximum of around 2 at GeV/c, arching over the data in linear
scale. The production of and are shown to arise mainly from the
recombination of thermal partons, thus exhibiting exponential dependences
in agreement with the data. Their ratio, , rises linearly to
GeV/c and develops a maximum at GeV/c. It is
argued that the spectra of and reveal directly the
partonic nature of the thermal source that characterizes quark-gluon plasma.
Comments are made on the puzzle due to the simultaneous observation of
both the exponential behavior of the spectrum in and the
existence of low- particles associated with as trigger.Comment: Revised manuscript with new figure
Final-State Interaction as the Origin of the Cronin Effect
Instead of adhering to the usual explanation of the Cronin effect in terms of
the broadening of the parton transverse momentum in the initial state, we show
that the enhancement of hadron production at moderate in d+Au collisions
is due to the recombination of soft and shower partons in the final state. Such
a mechanism can readily explain the decrease of the Cronin effect with
increasing rapidity. Furthermore, the effect should be larger for protons than
for pions.Comment: 4 RevTeX pages including 3 figures and 1 table; Some notational
changes and a corrected referenc
A Navier-Stokes Solution of Hull-Ring Wing-Thruster Interaction
Navier-Stokes simulations of high Reynolds number flow around an axisymmetric body supported in a water tunnel were made. The numerical method is based on a finite-differencing high resolution second-order accurate implicit upwind scheme. Four different configurations were investigated, these are: (1) barebody; (2) body with an operating propeller; (3) body with a ring wing; and (4) body with a ring wing and an operating propeller. Pressure and velocity components near the stern region were obtained computationally and are shown to compare favorably with the experimental data. The method correctly predicts the existence and extent of stern flow separation for the barebody and the absence of flow separation for the three other configurations with ring wing and/or propeller
On the Energy and Centrality Dependence of Higher Order Moments of Net-Proton Distributions in Relativistic Heavy Ion Collisions
The higher order moments of the net-baryon distributions in relativistic
heavy ion collisions are useful probes for the QCD critical point and
fluctuations. Within a simple model we study the colliding energy and
centrality dependence of the net-proton distributions in the central rapidity
region. The model is based on considering the baryon stopping and pair
production effects in the processes. Based on some physical reasoning, the
dependence is parameterized. Predictions for the net-proton distributions for
Au+Au and Pb+Pb collisions at different centralities at =39 and
2760 GeV, respectively, are presented from the parameterizations for the model
parameters. A possible test of our model is proposed from investigating the net
proton distributions in the non-central rapidity region for different colliding
centralities and energies.Comment: 6 pages in revtex4, 8 eps figures. arXiv admin note: text overlap
with arXiv:1107.474
Fast quantum information transfer with superconducting flux qubits coupled to a cavity
We present a way to realize quantum information transfer with superconducting
flux qubits coupled to a cavity. Because only resonant qubit-cavity interaction
and resonant qubit-pulse interaction are applied, the information transfer can
be performed much faster, when compared with the previous proposals. This
proposal does not require adjustment of the qubit level spacings during the
operation. Moreover, neither uniformity in the device parameters nor exact
placement of qubits in the cavity is needed by this proposal.Comment: 6 pages, 3 figure
- …