scholarly journals Controlled-scattering resonances in a spherical potential well

2017 ◽  
Vol 13 (4) ◽  
pp. 4888-4890
Author(s):  
Andrew Akala ◽  
C. Yinka Banjo
Keyword(s):  
Bound States ◽  
Bound State ◽  
Theoretical Concept ◽  
Nano Particles ◽  
Potential Well ◽  
Collision Processes ◽  
Spherical Potential ◽  
Scattering Resonances

Understanding of collision processes is required in designing robust nano-particles for future applications. This study proposes a technique for controlling scattering resonances by using the tuning of well parameters to impose pre-determined thresholds on resonances and bound states in collision processes. The theoretical concept of scattering in a spherical potential well, at varying depths was adopted. A scan of q from 0 to 5π at incremental steps of q= π/p yields (p x 5)+1 number of state(s), and p-1 state(s) resonate(s) at each bound state.

scholarly journals Bound states of a Klein–Gordon particle in the presence of a smooth potential well

2020 ◽  
Vol 35 (23) ◽  
pp. 2050140
Author(s):  
Eduardo López ◽  
Clara Rojas
Keyword(s):  
Bound States ◽  
Gordon Equation ◽  
Bound State ◽  
Potential Well ◽  
One Dimensional ◽  
Smooth Potential ◽  
Klein Gordon ◽  
The One ◽  
Potential Parameters ◽  
Klein Gordon Equation

We solve the one-dimensional time-independent Klein–Gordon equation in the presence of a smooth potential well. The bound state solutions are given in terms of the Whittaker [Formula: see text] function, and the antiparticle bound state is discussed in terms of potential parameters.

scholarly journals Spectral collapse in multiqubit two-photon Rabi model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
C. F. Lo
Keyword(s):  
Bound States ◽  
Energy Difference ◽  
Bound State ◽  
Potential Well ◽  
Critical Coupling ◽  
Nonlocal Potential ◽  
Two Photon ◽  
Rabi Model ◽  
Continuous Energy Spectrum ◽  
Bound State Problem

AbstractWe have shown that the smallest possible singel-qubit critical coupling strength of the N-qubit two-photon Rabi model is only 1/N times that of the two-photon Rabi model. The spectral collapse can thus occur at a more attainable value of the critical coupling. For both of the two-qubit and three-qubit cases, we have also rigorously demonstrated that at the critical coupling the system not only has a set of discrete eigenenergies but also a continuous energy spectrum. The discrete eigenenergy spectrum can be derived via a simple one-to-one mapping to the bound state problem of a particle of variable effective mass in the presence of a finite potential well and a nonlocal potential. The energy difference of each qubit, which specifies both the depth of the finite potential well and the strength of the nonlocal potential, determines the number of bound states available, implying that the extent of the incomplete spectral collapse can be monitored in a straightforward manner.

BOUND STATES AND KLEIN PARADOX OF GRAPHENE SYSTEMS IN CONFINING POTENTIALS

2012 ◽  
Vol 26 (17) ◽  
pp. 1250108
Author(s):  
HAI HUANG ◽  
XIA HUANG
Keyword(s):  
Dirac Equation ◽  
Bound States ◽  
Bound State ◽  
Linear Potential ◽  
Two Dimensional ◽  
Potential Well ◽  
Klein Paradox ◽  
Confining Potential ◽  
Potential Depth

Two-dimensional massive Dirac equation in both potential well and linear potential is discussed. We find that in the case of potential well, the bound states disappear from the spectrum for large enough potential depth. With the linear confining potential, we show that the Dirac equation presents no bound state. Both these results can be identified as fine examples of the Klein paradox. Applications to graphene systems are also discussed.

RETARDATION EFFECTS IN COVARIANT THREE-DIMENSIONAL BOUND STATE WAVE FUNCTIONS

2005 ◽  
Vol 14 (06) ◽  
pp. 931-947 ◽  
Author(s):  
F. PILOTTO ◽  
M. DILLIG
Keyword(s):  
Bound States ◽  
Three Dimensional ◽  
Bound State ◽  
Relative Energy ◽  
Wave Functions ◽  
Three Dimensions ◽  
State Wave ◽  
Scalar Diquark ◽  
Bound State Wave Function ◽  
Retardation Effects

We investigate the influence of retardation effects on covariant 3-dimensional wave functions for bound hadrons. Within a quark-(scalar) diquark representation of a baryon, the four-dimensional Bethe–Salpeter equation is solved for a 1-rank separable kernel which simulates Coulombic attraction and confinement. We project the manifestly covariant bound state wave function into three dimensions upon integrating out the non-static energy dependence and compare it with solutions of three-dimensional quasi-potential equations obtained from different kinematical projections on the relative energy variable. We find that for long-range interactions, as characteristic in QCD, retardation effects in bound states are of crucial importance.

THE NEXT STEP IN LEPTONIC DECAYS OF ETA AND KL BOUND STATES

1992 ◽  
Vol 07 (09) ◽  
pp. 1935-1951 ◽  
Author(s):  
G.A. KOZLOV
Keyword(s):  
Field Theory ◽  
Transition Form Factor ◽  
Bound States ◽  
Three Dimensional ◽  
Bound State ◽  
Quantum Field ◽  
Relative Momentum ◽  
Transition Form ◽  
Structure Transition ◽  
Leptonic Decays

A systematic discussion of the probability of eta and KL bound-state decays—[Formula: see text] and [Formula: see text](l=e, μ)—within a three-dimensional reduction to the two-body quantum field theory is presented. The bound-state vertex function depends on the relative momentum of constituent-like particles. A structure-transition form factor is defined by a confinement-type quark-antiquark wave function. The phenomenology of this kind of decays is analyzed.

scholarly journals Structural insights into the mechanism of the DEAH-box RNA helicase Prp43

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Marcel J Tauchert ◽  
Jean-Baptiste Fourmann ◽  
Reinhard Lührmann ◽  
Ralf Ficner
Keyword(s):  
Conformational Changes ◽  
Bound States ◽  
Rna Binding ◽  
Atp Hydrolysis ◽  
Bound State ◽  
Rna Helicases ◽  
Large Rearrangements ◽  
Rna Complex ◽  
Structural Insights ◽  
Terminal Domains

The DEAH-box helicase Prp43 is a key player in pre-mRNA splicing as well as the maturation of rRNAs. The exact modus operandi of Prp43 and of all other spliceosomal DEAH-box RNA helicases is still elusive. Here, we report crystal structures of Prp43 complexes in different functional states and the analysis of structure-based mutants providing insights into the unwinding and loading mechanism of RNAs. The Prp43•ATP-analog•RNA complex shows the localization of the RNA inside a tunnel formed by the two RecA-like and C-terminal domains. In the ATP-bound state this tunnel can be transformed into a groove prone for RNA binding by large rearrangements of the C-terminal domains. Several conformational changes between the ATP- and ADP-bound states explain the coupling of ATP hydrolysis to RNA translocation, mainly mediated by a β-turn of the RecA1 domain containing the newly identified RF motif. This mechanism is clearly different to those of other RNA helicases.

THE BETHE–SALPETER EQUATION APPROACH TO BOUND STATE: SCALAR–FERMION CASE AND SCALAR–SCALAR CASE

2007 ◽  
Vol 22 (39) ◽  
pp. 2979-2992 ◽  
Author(s):  
JIAO-KAI CHEN ◽  
ZHENG-XIN TANG ◽  
QING-DONG CHEN
Keyword(s):  
Bound States ◽  
Bound State ◽  
Wave Functions ◽  
Scalar Case ◽  
Equation Approach

The general form of the Bethe–Salpeter wave functions for bound states comprising one scalar constituent and one fermion, or two scalars is presented. Using the reduced Salpeter equation obtained, we can work out the effective nonrelativistic potentials. And one new version of reduced Bethe–Salpeter equation is proposed by extending Gross approximation.

scholarly journals Instability of charged massive scalar fields in bound states around Kerr–Sen black holes

2015 ◽  
Vol 24 (14) ◽  
pp. 1550102 ◽  
Author(s):  
Haryanto M. Siahaan
Keyword(s):  
Black Holes ◽  
Bound States ◽  
Gordon Equation ◽  
Scalar Fields ◽  
Bound State ◽  
Imaginary Component ◽  
Scalar Perturbation ◽  
Massive Scalar ◽  
Massive Scalar Field ◽  
Klein Gordon

In this paper, we show the instability of a charged massive scalar field in bound states around Kerr–Sen black holes. By matching the near and far region solutions of the radial part in the corresponding Klein–Gordon equation, one can show that the frequency of bound state scalar fields contains an imaginary component which gives rise to an amplification factor for the fields. Hence, the unstable modes for a charged and massive scalar perturbation in Kerr–Sen background can be shown.

Bound States of Spinless Particles in a Short-Range Potential

2015 ◽  
Vol 70 (4) ◽  
pp. 245-249 ◽  
Author(s):  
Hassan Hassanabadi ◽  
Antonio Soares de Castro
Keyword(s):  
Short Range ◽  
Bound States ◽  
Bound State ◽  
Scalar Coupling ◽  
Spinless Particle ◽  
Vector Coupling ◽  
Short Range Potential ◽  
Range Potential ◽  
Constraint Relation ◽  
Potential Parameters

AbstractWith a general mixing of vector and scalar couplings in a two-dimensional world, a short-range potential is used to explore certain features of the bound states of a spinless particle. Bound-state solutions are found in terms of the Gauss hypergeometric series when the potential parameters obey a certain constraint relation limiting the dosage of a vector coupling. The appearance of the Schiff–Snyder–Weinberg effect for a strong vector coupling and a short-range potential as well as its suppression by the addition of a scalar coupling is discussed.

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