APPROXIMATE |∆I| = 1/2 RULE IN K → ππ DECAYS FROM ASYMPTOTIC QUARK-LINE DIAGRAM APPROACH

1990 ◽  
Vol 05 (29) ◽  
pp. 2423-2430 ◽  
Author(s):  
K. TERASAKI ◽  
S. ONEDA

Approximate |∆I| = 1/2 rule in K → ππ decays is studied from a new dynamical perspective in which quark-line diagrams should only be associated with asymptotic single-hadron matrix elements of [Formula: see text], and not with the whole amplitude. The asymptotic matrix elements of [Formula: see text] taken between ordinary [Formula: see text] mesons are found to satisfy the strict |∆I| = 1/2 rule. However, the contribution of the four-quark (QQ)[Formula: see text] type mesons leads explicitly to a small violation of the selection rule.

2003 ◽  
Vol 81 (5) ◽  
pp. 755-769 ◽  
Author(s):  
A A Kamenski ◽  
V D Ovsiannikov

A regular method for deriving the consecutive terms of a series in powers of field strength F for the intensities of hydrogen radiation lines is presented both analytically and numerically. Specific modification of the perturbation theory for degenerate states and the Sturm-series expansion for the completely reduced Coulomb–Green function in parabolic coordinates are used to derive simple analytical formulas for matrix elements and the intensities of the radiation transitions between circular states. Particular cases of transitions between the closest Rydberg levels are presented and discussed in detail. Analytical expressions are also derived for the quadrupole matrix elements, which may contribute to the probability of σ-transitions with the selection rule for the magnetic quantum number Δm = ±1 and determine the probability of the dipole-forbidden radiation transitions between Stark levels with Δm = ±2. PACS Nos.: 32.60.+i, 32.70.–n, 32.70.Fw


2002 ◽  
Vol 80 (11) ◽  
pp. 1391-1399 ◽  
Author(s):  
V D Ovsiannikov ◽  
V V Chernushkin

The changes of the radiation matrix elements, probabilities, and line intensities in a strong magnetic field are studied for the helium lines, corresponding to transitions between Zeeman manifolds with |m| [Formula: see text] 3. The effect of a selective field action on radiation lines is discovered that may reduce and enhance corresponding matrix elements and induce the dipole-forbidden transitions with the selection rule |Δl| = 3. PACS Nos.: 32.60+i, 32.70Fw, 32.30-r


1985 ◽  
Vol 63 (9) ◽  
pp. 1151-1156 ◽  
Author(s):  
A. Lev ◽  
M. Schlesinger ◽  
G. W. F. Drake ◽  
R. D. Kent

A closed form expression for the evaluation of many-electron matrix elements in the unitary group approach to the theory of atomic structure is presented in terms of simple factors. In addition, a new selection rule for nonvanishing matrix elements is given.


2010 ◽  
Vol 19 (04) ◽  
pp. 685-691 ◽  
Author(s):  
A. DOBROWOLSKI ◽  
A. GÓŹDŹ ◽  
J. DUDEK

We consider many-body E-l transition matrix-elements between two nuclear states of different axially-symmetric deformations characterised by two different (mutually non-orthogonal) sets of single-particle wave-functions. Yet, when varying the deformations of the initial, final, or both these states one notices abrupt changes in the form of vanishing and possibly reappearance of the transition matrix elements calculated between the corresponding Slater determinants. The mechanism is explained in terms of the conservation of the |m| quantum number (absolute value of the projection of individual-nucleonic angular-momenta); consequences for the more general calculations of this type also without axial symmetry are discussed.


2005 ◽  
Vol 20 (20) ◽  
pp. 1533-1540 ◽  
Author(s):  
SHI-HAI DONG ◽  
M. LOZADA-CASSOU

In this letter, based on Hamiltonian identity we propose a generalized expression of the second hypervirial for an arbitrary central potential wave functions in higher dimensions D and then present a useful general recurrence relation among the off-diagonal multipolar matrix elements. We show that this new proposed recurrence formula is very powerful in deriving the recurrence relations among the hydrogenic matrix elements. Some important recurrence relations can be simply obtained. It is interesting to find that the selection rule is independent of the central potential V(r) for f = rk with k = 0, 2 and that the diagonal matrix elements of V′(r) are independent of the system eigenvalues for k = 1. The application of the general recurrence relation to the isotropic harmonic oscillator case is discussed briefly.


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