Search results for "correlation function"
showing 10 items of 164 documents
Relativistic Versus Nonrelativistic ΛN Correlations in the Weak Decay of Hypernuclei
1995
We establish the reasons for the different effect of short range correlations in the nonmesonic decay of Λ hypernuclei found by relativistic and nonrelativistic approaches. By means of a schematic microscopic model for the origin of correlations, the appropriate method to include them in nuclear processes, via a correlation function, is derived and is found to be the one used in the nonrelativistic approach.
Measurement of the correlation between flow harmonics of different order in lead-lead collisions at sNN=2.76 TeV with the ATLAS detector
2015
Correlations between the elliptic or triangular flow coefficients v(m) (m = 2 or 3) and other flow harmonics v(n) (n = 2 to 5) are measured using root S-NN = 2.76 TeV Pb + Pb collision data collected in 2010 by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 7 mu b(-1). The v(m)-v(n) correlations aremeasured in midrapidity as a function of centrality, and, for events within the same centrality interval, as a function of event ellipticity or triangularity defined in a forward rapidity region. For events within the same centrality interval, v(3) is found to be anticorrelated with v(2) and this anticorrelation is consistent with similar anticorrelations between th…
Quasi-deuteron effects at intermediate energies
2008
It has been shown that photon and pion reactions in certain energy regions are dominated by the absorption on correlated (n-p)-pairs. Therefore, calculations based on quasi-deuteron models describe rather well the present experimental results. However, with more accurate data out of the reactions (γ,np),(γ,N), (π,NN) and (π,N) performed so that the complete kinematics is known, the correlation function of nucleon pairs in nuclei can be studied a quantity very important for our understanding of the nuclear many body system. The dominance for absorption on pairs in reactions with a rather big mismatch in energy and momentum in the entrance channel compared with the exit channel of the reactio…
pp and ππ intensity interferometry in collisions of Ar+KCl at 1.76A GeV
2011
Results on pp, π+π+, and π-π- intensity interferometry are reported for collisions of Ar+KCl at 1.76$A$~GeV beam energy, studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18/GSI. The experimental correlation functions as a function of the relative momentum are compared to model calculations allowing the determination of the space-time extent of the corresponding emission sources. The π π source radii are found significantly larger than the pp emission radius. The present radii do well complement the source-size excitation functions of the collision system of size $A+A \simeq 40+40$. The pp source radius at fixed beam energy is found to increase linearly with the cube r…
All-optical measurements of background, amplitude, and timing jitters for high speed pulse trains or PRBS sequences using autocorrelation function
2008
International audience; We present a simple method for all-optical measurements of background, amplitude, and timing jitters of ultra high speed pulse trains or PRBS sequences using the jitter dependence of the intercorrelation-peak shape. This method is numerically and experimentally demonstrated on a 42.66 Gbit/s PRBS sequence and then applied to measure the jitter growths occurring during the propagation of a 160-GHz pulse train in a classical SMF/DCF dispersion map.
A Wideband One-Ring MIMO Channel Model Under Non-Isotropic Scattering Conditions
2008
In this paper, we present a wideband one-ring multiple-input multiple-output (MIMO) channel model for non-isotropic scattering environments. The model is designed in such a way that the delay power spectral density (PSD) of the resulting reference channel model is identical to a given delay PSD. Furthermore, we present an efficient deterministic channel simulation model obtained by using the principle of deterministic channel modeling. The statistical properties of both the reference model and the simulation model are also studied. Analytical expressions will be presented for the temporal autocorrelation function (ACF), the two-dimensional (2D) space cross-correlation function (CCF), and th…
Lattice QCD study of the $H$ dibaryon using hexaquark and two-baryon interpolators
2019
Physical review / D 99(7), 074505 (2019). doi:10.1103/PhysRevD.99.074505
Monte Carlo study of the ising model phase transition in terms of the percolation transition of “physical clusters”
1990
Finite squareL×L Ising lattices with ferromagnetic nearest neighbor interaction are simulated using the Swendsen-Wang cluster algorithm. Both thermal properties (internal energyU, specific heatC, magnetization 〈|M|〉, susceptibilityχ) and percolation cluster properties relating to the “physical clusters,” namely the Fortuin-Kasteleyn clusters (percolation probability 〈P∞〉, percolation susceptibilityχp, cluster size distributionnl) are evaluated, paying particular attention to finite-size effects. It is shown that thermal properties can be expressed entirely in terms of cluster properties, 〈P∞〉 being identical to 〈|M|〉 in the thermodynamic limit, while finite-size corrections differ. In contr…
First-Principles Study on Polymorphs of AgVO3: Assessing to Structural Stabilities and Pressure-Induced Transitions
2017
In this paper, we present a comprehensive theoretical study, based on density-functional theory calculations, and which focuses on the structural and electronic properties of silver vanadium oxide (AgVO3) in the monoclinic [Cm (β-AgVO3), C2/c (α-AgVO3), and Cc], orthorhombic (Amm2), and cubic (Pm3̅m) phases from 0–30 GPa. The structural and electronic properties, the stability of different phases, and the pressure-induced solid–solid phase transitions of AgVO3 have been previously studied. The effects of pressure on the band structures, energy–gap values, density of states, and vibrational frequencies are also studied. Numerical and analytical calculations are conducted to obtain the lattic…
Correlations between a Hawking particle and its partner in a 1+1D Bose-Einstein condensate analog black hole
2020
The Fourier transform of the density-density correlation function in a Bose-Einstein condensate (BEC) analog black hole is a useful tool to investigate correlations between the Hawking particles and their partners. It can be expressed in terms of $⟨{^{\mathrm{out}}\stackrel{^}{a}}_{\mathrm{up}}^{\mathrm{ext}}\text{ }\text{ }{^{\mathrm{out}}\stackrel{^}{a}}_{\mathrm{up}}^{\mathrm{int}}⟩$, where ${^{\mathrm{out}}\stackrel{^}{a}}_{\mathrm{up}}^{\mathrm{ext}}$ is the annihilation operator for the Hawking particle and ${^{\mathrm{out}}\stackrel{^}{a}}_{\mathrm{up}}^{\mathrm{int}}$ is the corresponding one for the partner. This basic quantity is calculated for three different models for the BEC f…