scholarly journals Theoretical Predictions of Low-Lying Three-Body Resonance States in 6He

1995 ◽  
Vol 94 (3) ◽  
pp. 343-352 ◽  
Author(s):  
S. Aoyama ◽  
S. Mukai ◽  
K. Kato ◽  
K. Ikeda
Keyword(s):  
Resonance States ◽  
Theoretical Predictions ◽  
Three Body

TWO-DIMENSIONAL WANG–LANDAU SAMPLING OF AN ASYMMETRIC ISING MODEL

2009 ◽  
Vol 20 (09) ◽  
pp. 1357-1366 ◽  
Author(s):  
SHAN-HO TSAI ◽  
FUGAO WANG ◽  
D. P. LANDAU
Keyword(s):  
Phase Diagram ◽  
Ising Model ◽  
External Field ◽  
Density Of States ◽  
Triangular Lattice ◽  
Sampling Method ◽  
Two Dimensional ◽  
Theoretical Predictions ◽  
The Spectator ◽  
Three Body

We study the critical endpoint behavior of an asymmetric Ising model with two- and three-body interactions on a triangular lattice, in the presence of an external field. We use a two-dimensional Wang–Landau sampling method to determine the density of states for this model. An accurate density of states allowed us to map out the phase diagram accurately and observe a clear divergence of the curvature of the spectator phase boundary and of the derivative of the magnetization coexistence diameter near the critical endpoint, in agreement with previous theoretical predictions.

scholarly journals Collision Broadening in the Inversion Spectrum of Methyl Chloride at Pressures up to Two Atmospheres

1964 ◽  
Vol 17 (2) ◽  
pp. 175 ◽  
Author(s):  
CH Burton ◽  
WB Lasich ◽  
JH Noon ◽  
RW Parsons
Keyword(s):  
Absorption Coefficient ◽  
Methyl Chloride ◽  
Wave Number ◽  
Pressure Broadening ◽  
Power Absorption ◽  
Rotational States ◽  
Theoretical Predictions ◽  
Collision Broadening ◽  
Three Body

The power absorption coefficient a of microwaves of wave number v = 0� 333cm-1 by methyl chloride at 33� 7�C has been studied at pressures up to 2 atm, and the results are compared with theoretical predictions. Discrepancies which have previously been attributed to the effect of transitions between low.lying rotational states are shown to be due to three� body collisions. The collision diameter for pressure broadening of theinversion transition in methyl chloride is found to be 8�6 A; this is significantly larger an the figure of 7 . 2 A reported by earlier workerswho neglected the effect of three-body ollisions.

scholarly journals Mott-insulator-aided detection of ultra-narrow Feshbach resonances

2018 ◽  
Vol 5 (5) ◽  
Author(s):  
Manfred Mark ◽  
Florian Meinert ◽  
Katharina Lauber ◽  
Hanns-Christoph Nägerl
Keyword(s):  
Three Dimensional ◽  
Mott Insulator ◽  
Atomic Ensemble ◽  
Feshbach Resonances ◽  
High Background ◽  
Type Molecule ◽  
Theoretical Predictions ◽  
Magnetic Field Region ◽  
Atom Loss ◽  
Three Body

We report on the detection of extremely narrow Feshbach resonances by employing a Mott-insulating state for cesium atoms in a three-dimensional optical lattice. The Mott insulator protects the atomic ensemble from high background three-body losses in a magnetic field region where a broad Efimov resonance otherwise dominates the atom loss in bulk samples. Our technique reveals three ultra-narrow and previously unobserved Feshbach resonances in this region with widths below \approx 10\,\mu≈10μG, measured via Landau-Zener-type molecule formation and confirmed by theoretical predictions. For comparatively broader resonances we find a lattice-induced substructure in the respective atom-loss feature due to the interplay of tunneling and strong particle interactions. Our results provide a powerful tool to identify and characterize narrow scattering resonances, particularly in systems with complex Feshbach spectra. The observed ultra-narrow Feshbach resonances could be interesting candidates for precision measurements.

scholarly journals Three-body resonance states just below the antiproton and hydrogen dissociation threshold

2018 ◽  
Vol 181 ◽  
pp. 01034
Author(s):  
Takuma Yamashita ◽  
Yasushi Kino
Keyword(s):  
Matrix Theory ◽  
Resonance State ◽  
Relative Energy ◽  
Positive Energy ◽  
Present Calculation ◽  
Resonance States ◽  
R Matrix ◽  
Hydrogen Dissociation ◽  
Dissociation Threshold ◽  
Three Body

We analyze two shallow resonance states below the antiproton hydrogen dissociation threshold with a non-adiabatic three-body calculation. Rearrangement correlation between initial channel and protonium formation channel is explicitly included in the total wavefunction. The lower resonance state is in good agreement with the resonance position and width calculated with the R-matrix theory. The higher resonance state which is newly found is closer to the threshold and much narrower than the former resonance. A polarization effect of the hydrogen atom is found to be indispensable to support the resonance state. The accuracy of the present calculation is evaluated by the extended virial theorem. The resonance states calculated in the present work gives shallower relative energy below the dissociation threshold than the Born-Oppenheimer calculation, suggesting that the electron motion which is ignored in latter calculation would give positive energy because the electron is unbound inside the distance.

THREE-BODY INTERACTIONS BEYOND THE GROSS–PITAEVSKII EQUATION AND MODULATIONAL INSTABILITY OF BOSE–EINSTEIN CONDENSATES

2012 ◽  
Vol 26 (32) ◽  
pp. 1250202 ◽  
Author(s):  
DIDIER BELOBO BELOBO ◽  
GERMAIN HUBERT BEN-BOLIE ◽  
TIMOLEON CREPIN KOFANE
Keyword(s):  
Modulational Instability ◽  
Mean Field Theory ◽  
Mean Field ◽  
External Potential ◽  
Pitaevskii Equation ◽  
Theoretical Predictions ◽  
The Mean ◽  
Three Body ◽  
Bose Einstein ◽  
Condensate System

Beyond the mean-field theory, a new model of the Gross–Pitaevskii equation (GPE) that describes the dynamics of Bose–Einstein condensates (BECs) is derived using an appropriate phase-imprint on the old wavefunction. This modified version of the GPE in addition to the two-body interactions term, also takes into account effects of the three-body interactions. The three-body interactions consist of a quintic term and the delayed nonlinear response of the condensate system term. Then, the modulational instability (MI) of the new GPE confined in an attractive harmonic potential is investigated. The analytical study shows that the three-body interactions destabilize more the condensate system while the external potential alleviates the instability. Numerical results confirm the theoretical predictions. Further numerical investigations of the behavior of solitons reveal that the three-body interactions enhance the appearance of solitons, increase the number of solitons generated and deeply change the lifetime of solitons. Moreover, the external potential delays the appearance of solitons. Besides, a new initial condition is introduced which enables to increase the number of solitons created and deeply affects the trail of chains of solitons generated. Moreover, the MI of a condensate without the external potential, and in a repulsive potential is also investigated.

scholarly journals A determination of fundamental constants using HD+ ion and atomic hydrogen spectroscopy data

2019 ◽  
Vol 198 ◽  
pp. 00005 ◽  
Author(s):  
Florin Lucian Constantin
Keyword(s):  
Quantum Electrodynamics ◽  
Atomic Hydrogen ◽  
Electron Mass ◽  
Fundamental Constants ◽  
Spectroscopy Data ◽  
Mass Ratio ◽  
Proton Mass ◽  
Theoretical Predictions ◽  
Three Body

A determination of fundamental constants using HD+ ion spectroscopy data is discussed from comparisons between precision measurements and accurate theoretical predictions by taking into account recent measurements and updated CODATA values of the fundamental constants. The deuteron-proton mass ratio is determined with an uncertainty of 10-9. The ratio between the HD+ reduced mass and the electron mass is determined with an uncertainty of 7.3 × 10-10. The Rydberg constant, the proton-electron mass ratio and the deuteron-electron mass ratio are consistently determined with 10-9 , 10-6 , and 10-6 level uncertainties from an adjustment of the (v,L)=(0,0)→(0,1) and (v,L)=(0,2)→(8,3) HD+ ion transitions and of the (n,l,j,f)=1S1/2f=1→2S1/2f=1 atomic hydrogen transition. The result of the adjustment provides a test of the consistency of the two-body and three-body quantum electrodynamics energy level calculations for the atomic hydrogen and the HD+ ion.

THREE-BODY EFFECTS IN $\vec{p}d$ ELASTIC SCATTERING AT 250 MEV

2003 ◽  
Vol 18 (02n06) ◽  
pp. 313-316 ◽  
Author(s):  
Y. SHIMIZU ◽  
K. HATANAKA ◽  
Y. SAKEMI ◽  
T. WAKASA ◽  
H. P. YOSHIDA ◽  
...  
Keyword(s):  
Elastic Scattering ◽  
Spin Structure ◽  
Nucleon Nucleon ◽  
Angular Distributions ◽  
Transfer Coefficients ◽  
Nucleon Force ◽  
Theoretical Predictions ◽  
Relativistic Treatment ◽  
Three Body ◽  
Polarization Transfer Coefficients

The angular distributions of the cross section, the proton analyzing power and all of proton polarization transfer coefficients of [Formula: see text] elastic scattering were measured at 250 MeV. The present data are compared with theoretical predictions based on exact solutions of the three-nucleon Faddeev equations and modern realistic nucleon-nucleon potentials combined with three-nucleon forces. These results call for a better understanding of the spin structure of the three-nucleon force and very likely for a full relativistic treatment of the three-nucleon continuum.

scholarly journals Interference effects in the decay of resonance states in three-body Coulomb systems

1999 ◽  
Vol 60 (6) ◽  
pp. 4673-4692 ◽  
Author(s):  
Oleg I. Tolstikhin ◽  
Inga Yu. Tolstikhina ◽  
Chusei Namba
Keyword(s):  
Coulomb Systems ◽  
Interference Effects ◽  
Resonance States ◽  
Three Body

Potential parameters and surface areas from third-order gas–solid interactions

1968 ◽  
Vol 46 (10) ◽  
pp. 1781-1785 ◽  
Author(s):  
Robert. Wolfe. ◽  
John. R. Sams
Keyword(s):  
Interaction Potential ◽  
Effective Interaction ◽  
Interaction Model ◽  
Third Order ◽  
Potential Models ◽  
Saturation Phenomenon ◽  
Surface Areas ◽  
Theoretical Predictions ◽  
Three Body ◽  
Potential Parameters

Values of the effective interaction potential between a pair of adsorbed molecules are evaluated in terms of different potential models for argon adsorbed on two carbon surfaces. The resultant three-body (admolecule–admolecule–solid) energies are not in accord with independent theoretical predictions. It is suggested that the results may be indicative of a saturation phenomenon. The apparent areas of both powders are nearly independent of the assumed interaction model, a fact which lends weight to the quantitative significance of surface areas determined by this method.

Microcalorimeters for X-Ray Spectroscopy

1988 ◽  
Vol 102 ◽  
pp. 41
Author(s):  
E. Silver ◽  
C. Hailey ◽  
S. Labov ◽  
N. Madden ◽  
D. Landis ◽  
...  
Keyword(s):  
High Resolution ◽  
High Efficiency ◽  
Thermal Response ◽  
Low Noise ◽  
High Resolution Spectroscopy ◽  
Superconducting Transition ◽  
Sapphire Substrates ◽  
Laboratory Plasmas ◽  
Adiabatic Demagnetization ◽  
Theoretical Predictions

The merits of microcalorimetry below 1°K for high resolution spectroscopy has become widely recognized on theoretical grounds. By combining the high efficiency, broadband spectral sensitivity of traditional photoelectric detectors with the high resolution capabilities characteristic of dispersive spectrometers, the microcalorimeter could potentially revolutionize spectroscopic measurements of astrophysical and laboratory plasmas. In actuality, however, the performance of prototype instruments has fallen short of theoretical predictions and practical detectors are still unavailable for use as laboratory and space-based instruments. These issues are currently being addressed by the new collaborative initiative between LLNL, LBL, U.C.I., U.C.B., and U.C.D.. Microcalorimeters of various types are being developed and tested at temperatures of 1.4, 0.3, and 0.1°K. These include monolithic devices made from NTD Germanium and composite configurations using sapphire substrates with temperature sensors fabricated from NTD Germanium, evaporative films of Germanium-Gold alloy, or material with superconducting transition edges. A new approache to low noise pulse counting electronics has been developed that allows the ultimate speed of the device to be determined solely by the detector thermal response and geometry. Our laboratory studies of the thermal and resistive properties of these and other candidate materials should enable us to characterize the pulse shape and subsequently predict the ultimate performance. We are building a compact adiabatic demagnetization refrigerator for conveniently reaching 0.1°K in the laboratory and for use in future satellite-borne missions. A description of this instrument together with results from our most recent experiments will be presented.

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