scholarly journals Third-order non-Coulomb correction to the S-wave quarkonium wave functions at the origin

2008 ◽  
Vol 658 (5) ◽  
pp. 222-229 ◽  
Author(s):  
M. Beneke ◽  
Y. Kiyo ◽  
K. Schuller

A perturbation calculation, valid in the limit of large separations, of various properties of the 2 pπ state of HeH 2+ is carried out. The total energy and the kinetic and potential energies are calculated to the fifth order, the dipole moment to the third order and the quadrupole moments to the second order and the results compared with those obtained using exact and variationally determined two-centre wave functions. Some results are also given for the 2 pπ u and 3 dπ g states of H + 2 and the influence of nuclear symmetry at large separations is briefly discussed.


2014 ◽  
Vol 23 (08) ◽  
pp. 1450039 ◽  
Author(s):  
U. Laha ◽  
J. Bhoi

By exploiting supersymmetry inspired factorization method nucleon–nucleon (n–n) potentials, both energy dependent and independent, in the partial waves 1P1 and 3P1 are generated by judicious use of appropriate ground state wave functions and interactions. The energy independent Hulthen and energy dependent equivalent local Yamaguchi potentials and their corresponding S-wave functions are used as the starting point of our calculation. The scattering phase shifts are computed for the constructed potentials through Phase Function Method (PFM) and compared with the standard results to examine the merit of our approach to the problem.


Author(s):  
Guang-Juan Wang ◽  
Lu Meng ◽  
Li-Ye Xiao ◽  
Makoto Oka ◽  
Shi-Lin Zhu

AbstractWe systematically study the mass spectrum and strong decays of the S-wave $${\bar{c}}{\bar{s}} q q$$ c ¯ s ¯ q q states in the compact tetraquark scenario with the quark model. The key ingredients of the model are the Coulomb, the linear confinement, and the hyperfine interactions. The hyperfine potential leads to the mixing between different color configurations, and to the large mass splitting between the two ground states with $$I(J^P)=0(0^+)$$ I ( J P ) = 0 ( 0 + ) and $$I(J^P)=1(0^+)$$ I ( J P ) = 1 ( 0 + ) . We calculate their strong decay amplitudes into the $${\bar{D}}^{(*)}K^{(*)}$$ D ¯ ( ∗ ) K ( ∗ ) channels with the wave functions from the mass spectrum calculation and the quark-interchange method. We examine the interpretation of the recently observed $$X_0(2900)$$ X 0 ( 2900 ) as a tetraquark state. The mass and decay width of the $$I(J^P)=1(0^+)$$ I ( J P ) = 1 ( 0 + ) state are $$M=2941$$ M = 2941 MeV and $$\Gamma _X=26.6$$ Γ X = 26.6 MeV, respectively, which indicates that it might be a good candidate for $$X_0(2900)$$ X 0 ( 2900 ) . Meanwhile, we also obtain an isospin partner state $$I(J^P)=0(0^+)$$ I ( J P ) = 0 ( 0 + ) with $$M=2649$$ M = 2649 MeV and $$\Gamma _{X\rightarrow {\bar{D}} K}=48.1$$ Γ X → D ¯ K = 48.1 MeV, respectively. Future experimental search for X(2649) will be very helpful.


1996 ◽  
Vol 74 (7-8) ◽  
pp. 335-342 ◽  
Author(s):  
J. W. Humberston ◽  
P. Van Reeth

Detailed investigations were made of positron collisions with helium atoms in the Ore gap using a two-channel version of the Kohn variational method with very flexible trial wave functions and accurate correlated helium-target wave functions. Accurate values of the s-wave elastic scattering and positronium-formation cross sections are presented, together with preliminary values of the cross sections for s-wave scattering. The s-wave positronium-formation cross section in helium displays a remarkable similarity in both magnitude and energy dependence to the corresponding cross section in positron–hydrogen scattering, with a rapid rise from the positronium-formation threshold and a more gradual rise thereafter. Its small magnitude is consistent with the findings of a recent analysis of experimental measurements of the positronium-formation cross section. Calculations of the s-wave elastic-scattering cross section above and below the positronium-formation threshold reveal a Wigner "rounded step" at the threshold itself.


2006 ◽  
Vol 84 (12) ◽  
pp. 1097-1106
Author(s):  
Liming He ◽  
Wei Cao

With many-body perturbation theory, 1D–3D term intervals of helium 1snd (n = 12 ∼ 20) configurations are calculated. Based on two different models, Rayleigh-Schrodinger perturbation expansion terms consisting of bound states only, and those of continua are evaluated, respectively. As for bound states, zeroth-order wave functions are strictly generated from self-iteration solutions of the Hartree equation and residues of infinite expansion series are dealt with by the integral processing method, while a simplified hydrogen potential is adopted to get the continua. Using Rayleigh–Schrodinger expansions, we evaluate exchange energy up to third-order terms. It is found that level splittings are mainly attributed to summations over bound states. The fine-structure level splittings yielded here are found to agree quite well with experimental results.PACS Nos.: 31.15.Md, 32.10Fn, 02.60Ed


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