Condensate fraction and momentum distribution in the ground state of liquidHe4

1985 ◽  
Vol 31 (11) ◽  
pp. 7022-7028 ◽  
Author(s):  
E. Manousakis ◽  
V. R. Pandharipande ◽  
Q. N. Usmani
Keyword(s):  
Momentum Distribution ◽  
Ground State ◽  
Condensate Fraction

Condensate fraction and momentum distribution in the ground state of liquidHe4

1991 ◽  
Vol 43 (16) ◽  
pp. 13587-13589 ◽  
Author(s):  
E. Manousakis ◽  
V. R. Pandharipande ◽  
Q. N. Usmani
Keyword(s):  
Momentum Distribution ◽  
Ground State ◽  
Condensate Fraction

scholarly journals Two Flavors of Hydrogen Atoms: A Possible Explanation of Dark Matter

Atoms ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 33 ◽  
Author(s):  
Eugene Oks
Keyword(s):  
Dark Matter ◽  
Dirac Equation ◽  
Early Universe ◽  
Momentum Distribution ◽  
Ground State ◽  
Singular Solution ◽  
High Energy ◽  
Hydrogen Atoms ◽  
High Energy Tail ◽  
Theoretical Results

In one of our previous papers, it was shown that for the ground state of hydrogenic atoms/ions, it is possible to match the interior (inside the nucleus) solution of the Dirac equation with the singular exterior solution of the Dirac equation, so that the singular solution should not be rejected for the ground state of hydrogenic atoms/ions. In that paper, there was presented also the first experimental proof of the existence of this Alternative Kind of Hydrogen Atoms (AKHA)—by showing that the presence of the AKHA solves a long-standing mystery of the huge discrepancy between the experimental and previous theoretical results concerning the high-energy tail of the linear momentum distribution in the ground state of hydrogen atoms. In another paper, we showed that for hydrogen atoms, the singular solution of the Dirac equation outside the proton is legitimate not just for the ground state 12S1/2, but also for the states 22S1/2, 32S1/2 and so on: it is legitimate for all the discrete states n2S1/2. Moreover, the singular exterior solution is legitimate also for the l = 0 states of the continuous spectrum. In that paper, we demonstrated that the AKHA can be the basis for explaining the recent puzzling astrophysical observational results concerning the redshifted radio line 21 cm from the early Universe. Thus, there seems to be the astrophysical evidence of the existence of the AKHA—in addition to the already available observational proof of their existence from atomic experiments. In the present paper, we point out that the AKHA provide an alternative view on dark matter—without resorting to new subatomic particles or dramatically changing the existing physical laws. This is because due to the selection rules, the AKHA do not have state that can be coupled by the electric dipole radiation. We also reformulate the above theoretical results in terms that hydrogen atoms can have two flavors: one flavor corresponding to the regular solution outside the proton, another—to the singular solution outside the proton, both solutions corresponding to the same energy. Since this means the additional degeneracy, then according to the fundamental theorem of quantum mechanics, there should be an additional conserved quantity, which we call isohydrogen spin (isohyspin). Further atomic experiments for accurately measuring the high-energy tail of the linear momentum distribution in the ground state of hydrogen atoms, as well as further observational studies of the redshifted 21 cm radio line from the early Universe, could provide a further proof that dark matter or a part of it is the AKHA.

scholarly journals The lifetime of axion stars

2016 ◽  
Vol 31 (15) ◽  
pp. 1650090 ◽  
Author(s):  
Joshua Eby ◽  
Peter Suranyi ◽  
L. C. R. Wijewardhana
Keyword(s):  
Momentum Distribution ◽  
Ground State ◽  
Transition Rate ◽  
Decay Constant ◽  
State Energy ◽  
Gravitational Instability ◽  
Big Bang ◽  
Weakly Bound ◽  
Axion Field ◽  
The Big Bang

We investigate the decay of condensates of scalars in a field theory defined by [Formula: see text], where [Formula: see text] and [Formula: see text] are the mass and decay constant of the scalar field. An example of such a theory is that of the axion, in which case the condensates are called axion stars. The axion field, [Formula: see text], is self-adjoint. As a result, the axion number is not an absolutely conserved quantity. Therefore, axion stars are not stable and have finite lifetimes. Bound axions, localized on the volume of the star, have a coordinate uncertainty [Formula: see text], where [Formula: see text] is the radius of the star and [Formula: see text]. Here [Formula: see text] and [Formula: see text] are the mass, and the ground state energy of the bound axion. Then the momentum distribution of axions has a width of [Formula: see text]. At strong binding, [Formula: see text], bound axions can easily transfer a sufficient amount of momentum to create and emit a free axion, leading to fast decay of the star with a transition rate [Formula: see text]. However, when [Formula: see text], the momentum distribution is more restricted, and as shown in this paper, the transition rate for creating a free axion decreases as [Formula: see text]. Then sufficiently large, weakly bound axion stars, produced after the Big Bang, survive until the present time. We plot the region of their stability, limited by decay through axion loss and by gravitational instability, as a function of the mass of the axion and the mass of the star.

scholarly journals The proton-pickup reactions as a means to study the spin-polarization and the magnetic moments in 35,37K

2019 ◽  
Vol 14 ◽  
pp. 101
Author(s):  
T. J. Mertzimekis ◽  
P. F. Mantica ◽  
A. D. Davies ◽  
S. N. Liddick ◽  
B. E. Tomlin
Keyword(s):  
Spin Polarization ◽  
Momentum Distribution ◽  
Magnetic Moment ◽  
Ground State ◽  
Magnetic Moments ◽  
Single Proton ◽  
Intermediate Energies ◽  
Unstable Nuclei ◽  
Fragmentation Reactions

Spin polarization in fragmentation reactions has been studied in several nuclei showing mainly that large polarization is produced at the tail of the fragments momentum distribution. Such polarization features are not so well known in pickup reactions, especially in studies of unstable nuclei, such as 35K and 37K. The spin polarization of 35K and 37K produced in single-proton pickup reactions at intermediate energies at the Coupled Cyclotrons at NSCL and the results for the ground-state magnetic moment involving the /3-NMR technique are reported in the present work.

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