共查询到20条相似文献,搜索用时 46 毫秒
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通过求解Faddeev方程, 研究了量子三体系统中的Efimov效应。 改进了变分方法对于求解激发态的不足。 在不同的两体作用下得到了三体系统中的Efimov态。 讨论了在不同质量比的三体系统中出现Efimov态的条件。 并由三体计算的结果分析了具有两个价中子的核系统在两体存在束缚态时可能存在的Efimov效应。We studied the Efimov effect in a three body system by solving the Faddeev equations. Different models and interactions were considered. The occurrence of Efimov states was discussed. The possible Efimov state was clearly presented and its properties were investigated. 相似文献
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Berninger M Zenesini A Huang B Harm W Nägerl HC Ferlaino F Grimm R Julienne PS Hutson JM 《Physical review letters》2011,107(12):120401
We report on the observation of triatomic Efimov resonances in an ultracold gas of cesium atoms. Exploiting the wide tunability of interactions resulting from three broad Feshbach resonances in the same spin channel, we measure magnetic-field dependent three-body recombination loss. The positions of the loss resonances yield corresponding values for the three-body parameter, which in universal few-body physics is required to describe three-body phenomena and, in particular, to fix the spectrum of Efimov states. Our observations show a robust universal behavior with a three-body parameter that stays essentially constant. 相似文献
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The scale invariance manifested by the weakly-bound Efimov states implies that all the Efimov spectrum can be merged in a single scaling function. By considering this scaling function, the ratio between two consecutive energy levels, ${E_3^{\rm (N+1)}}$ and ${E_3^{\rm (N)}}$ , can be obtained from a two-body low-energy observable (usually the scattering length a), given in units of the three-body energy level N. The zero-ranged scaling function is improved by incorporating finite range corrections in first order of r 0/a (r 0 is the potential effective range). The critical condition for three-identical bosons in s-wave, when the excited ${E_3^{\rm (N+1)}}$ state disappears in the 2 + 1 threshold, is given by ${\sqrt{E_2/E_3^{\rm (N)}} \approx 0.38+0.12 ({r_0}/{a})}$ . 相似文献
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It is shown, using a Born-Oppenheimer model, that the four-body Efimov effect may occur in a system consisting of three identical heavy particles and one light particle, if the light-heavy interaction leads to a zeroenergy two-heavy-one-light bound state. 相似文献
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A. V. Sobolev 《Communications in Mathematical Physics》1993,156(1):101-126
We study a three-particle Schrödinger operatorH for which none of the two-particle subsystems has negative bound states and at least two of them have zero energy resonances. We prove that under this condition the numberN(z) of bound states ofH belowz<0 has the asymptotics
asz-0, where the coefficient
depends only on the ratio of masses of the particles. 相似文献
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W. Plessas 《Few-Body Systems》1987,2(1):N17-N17
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G. Karner 《Few-Body Systems》1987,3(1):7-25
We employ a Birman-Schwinger type analysis to derive estimates on the number of bound-states of certainN-body systems with threshold-energy =inf ess(H) supposed to be zero. For many-body systems without any substructure we show that eigenvalues of the Schrödinger operatorH absorbed at =0 are in the point-spectrum ofH. Furthermore we characterize a multiparticle equivalent of the Efimov effect. 相似文献
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We review the results obtained in the last four decades which demonstrate the Efimov nature of the 4He three-atomic system. 相似文献
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Abstact: The composition of forward-going projectile spectator matter in fixed-target Pb+Pb collisions at 158 A · GeV at the CERN
SPS has been studied as a function of centrality. The data were measured with the NA49 veto calorimeter. We observe that forward-going
spectator matter in central collisions consists of 9 neutrons, 7 protons, and half a deuteron on average. At large impact
parameters most spectator nucleons are bound in fragments. The relative resolution of the average impact parameter derived
from the measurement of spectator neutrons is roughly 19% in the range from zero to half maximum impact parameters.
Received: 16 February 1998 / Revised version: 30 March 1998 相似文献
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N. T. Zinner 《Few-Body Systems》2013,54(5-6):597-603
Near a Feshbach resonance, the two-body scattering length can assume any value. When it approaches zero, the next-order term given by the effective range is known to diverge. We consider the question of whether this divergence (and the vanishing of the scattering length) is accompanied by an anomalous solution of the three-boson Schrödinger equation similar to the one found at infinite scattering length by Efimov. Within a simple zero-range model, we find no such solutions, and conclude that higher-order terms do not support Efimov physics. 相似文献
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The photoassociation of Efimov trimer, composed of three identical bosons, is studied using the long wavelength approximation. It is shown that for identical particles the leading contribution comes from the r 2 s-mode operator and from the quadrupole d-mode operator. Log-periodic oscillations are found in the photoassociation response function, both near the energy threshold for the leading s-wave reaction, and in the high frequency tail for all partial waves. 相似文献
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Remco van der Hofstad Wolfgang König Peter Mörters 《Communications in Mathematical Physics》2006,267(2):307-353
We discuss the long time behaviour of the parabolic Anderson model, the Cauchy problem for the heat equation with random potential on $\mathbb{Z}^{d}We discuss the long time behaviour of the parabolic Anderson model, the Cauchy problem for the heat equation with random potential on. We consider general i.i.d. potentials and show that exactly four qualitatively different types of intermittent behaviour can occur. These four universality classes depend on the upper tail of the potential distribution: (1) tails at ∞ that are thicker than the double-exponential tails, (2) double-exponential tails at ∞ studied by G?rtner and Molchanov, (3) a new class called almost bounded potentials, and (4) potentials bounded from above studied by Biskup and K?nig. The new class (3), which contains both unbounded and bounded potentials, is studied in both the annealed and the quenched setting. We show that intermittency occurs on unboundedly increasing islands whose diameter is slowly varying in time. The characteristic variational formulas describing the optimal profiles of the potential and of the solution are solved explicitly by parabolas, respectively, Gaussian densities. Our analysis of class (3) relies on two large deviation results for the local times of continuous-time simple random walk. One of these results is proved by Brydges and the first two authors in [BHK04], and is also used here to correct a proof in [BK01]. 相似文献
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We propose the unification of weak, electromagnetic and strong interactions within a gauge theory based on the chiral group of elementary fermions (quarks and leptons). Several consequences, in particular one with respect to neutral currents in the weak interactions, are discussed. 相似文献
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We study two-body correlations in systems of identical bosons. We use a Faddeev type of decomposition of the wave function where all pairs of particles are treated equally. At large scattering length appears a series of Efimov-like states, i.e., spatially extended, model-independent many-body bound states inside the trap. They may play a role in the decay of Bose-Einstein condensates. 相似文献