Chi-Yu Hu

Three-potential formalism for the three-body scattering problem with attractive Coulomb interactions

A three-body scattering process in the presence of Coulomb interaction can be decomposed formally into two-body single channel scattering, two-body multichannel scattering, and genuine three-body scattering. The corresponding integral equations are coupled Lippmann-Schwinger and Faddeev-Merkuriev integral equations. We solve these by applying the Coulomb-Sturmian separable expansion method. We present elastic scattering and reaction cross sections of the

Low-energy antihydrogen formation cross sections and differential cross sections via the modified Faddeev equations

{e}^{+}+H

The modified Faddeev equation and multichannel positron-hydrogen scattering calculation

system both below and above the

Faddeev–Merkuriev equations for resonances in three-body Coulombic systems

H(n=2)

Resonant-state solution of the Faddeev-Merkuriev integral equations for three-body systems with Coulomb potentials

threshold. We find excellent agreements with previous calculations in most cases.

Low-energy anti-hydrogen formation differential cross sections from Ps(n = 2) via the modified Faddeev equations

This paper includes cross sections and differential cross sections for the processes + ps(1s)→e + (n≤2), assuming CPT symmetry and using ten partial waves with total angular momentum L ≤ 9. Comparisons with previous calculations are made whenever feasible and good agreement is observed. It is noted that the forward peaks of the differential cross sections of the formation of (2p) atoms are much broader than those of the formation of S-state atoms. A strong secondary maximum of one of the (2p) formation processes is centred around 45°, in contrast to S-state processes at comparable energies where the differential cross sections are strongly peaked in the forward direction with θ < 40°. The combined differential cross sections of the two processes that lead to the formation of (2p) are also given for a number of energies.

Resonances and excitation of levels in scattering via the Faddeev approach

A bipolar spherical harmonics expansion of the modified Faddeev equation is used to calculate the K-matrices of the e++H scattering for up to five open channels and for total angular momentum L4. Partial cross sections and differential cross sections including hydrogen production channels are reported. Comparison with previous calculations are made whenever feasible. Good agreement is observed.

Hyperfine transitions and fusion in flight via the Faddeev approach

Abstract We reconsider the homogeneous Faddeev–Merkuriev integral equations for three-body Coulombic systems with attractive Coulomb interactions and point out that the resonant solutions are contaminated with spurious resonances. The spurious solutions are related to the splitting of the attractive Coulomb potential into short- and long-range parts, which is inherent in the approach, but arbitrary to some extent. By varying the parameters of the splitting the spurious solutions can easily be ruled out. We solve the integral equations by using the Coulomb–Sturmian separable expansion approach. This solution method provides an exact description of the threshold phenomena. We have found several new S-wave resonances in the e−e+e− system in the vicinity of thresholds.

Faddeev calculations of muonic-atom collisions: Scattering and fusion in flight.

A novel method for calculating resonances in three-body Coulombic systems is presented. The Faddeev-Merkuriev integral equations are solved by applying the Coulomb-Sturmian separable expansion method. To show the power of the method we calculate resonances of the three-α and the H − systems.

Direct solution of the Faddeev equations for the three-body Coulomb problem with L=0.

Assuming CPT symmetry, we carried out calculations for the system +Ps (n = 2) in the eight open channels energy gap between the Ps(n = 2) and (n = 3) energy thresholds where we found anti-hydrogen formation cross sections as high as 1670 πa02. We also report well converged anti-hydrogen formation differential cross sections from Ps(n = 2) targets using less than 10 partial waves. Very near the Ps(n = 2) threshold the differential cross sections are dominated by the first three partial waves where most of the interference minimal structures seen in other energy regions are absent. Of particular interest are the large cross section and the absence of interference minima in the differential cross sections when the target is in the metastable 2 3S1 state. The possibility of utilizing these processes for low-energy anti-hydrogen synthesis is discussed.