1,387 research outputs found
Benchmark calculations for elastic fermion-dimer scattering
We present continuum and lattice calculations for elastic scattering between
a fermion and a bound dimer in the shallow binding limit. For the continuum
calculation we use the Skorniakov-Ter-Martirosian (STM) integral equation to
determine the scattering length and effective range parameter to high
precision. For the lattice calculation we use the finite-volume method of
L\"uscher. We take into account topological finite-volume corrections to the
dimer binding energy which depend on the momentum of the dimer. After
subtracting these effects, we find from the lattice calculation kappa a_fd =
1.174(9) and kappa r_fd = -0.029(13). These results agree well with the
continuum values kappa a_fd = 1.17907(1) and kappa r_fd = -0.0383(3) obtained
from the STM equation. We discuss applications to cold atomic Fermi gases,
deuteron-neutron scattering in the spin-quartet channel, and lattice
calculations of scattering for nuclei and hadronic molecules at finite volume.Comment: 16 pages, 5 figure
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Perturbed Angular Distributions from 120,122, 124Sn(40Ar, 4n)156, 158, 160Er Reaction Products Recoiling in Vacuum
A quotient of the Lubin-Tate tower II
In this article we construct the quotient M_1/P(K) of the infinite-level
Lubin-Tate space M_1 by the parabolic subgroup P(K) of GL(n,K) of block form
(n-1,1) as a perfectoid space, generalizing results of one of the authors (JL)
to arbitrary n and K/Q_p finite. For this we prove some perfectoidness results
for certain Harris-Taylor Shimura varieties at infinite level. As an
application of the quotient construction we show a vanishing theorem for
Scholze's candidate for the mod p Jacquet-Langlands and the mod p local
Langlands correspondence. An appendix by David Hansen gives a local proof of
perfectoidness of M_1/P(K) when n = 2, and shows that M_1/Q(K) is not
perfectoid for maximal parabolics Q not conjugate to P.Comment: with an appendix by David Hanse
Confirmation of Parity Violation in the Gamma Decay of
This paper reports measurements using the technique of On Line Nuclear
Orientation (OLNO) which reexamine the gamma decay of isomeric Hf and specifically the 501 keV 8 -- 6
transition. The irregular admixture of E2 to M2/E3 multipolarity in this
transition, deduced from the forward-backward asymmetry of its angular
distribution, has for decades stood as the prime evidence for parity mixing in
nuclear states. The experiment, based on ion implantation of the newly
developed mass-separated Hf beam at ISOLDE, CERN into an
iron foil maintained at millikelvin temperatures, produces higher degrees of
polarization than were achieved in previous studies of this system. The value
found for the E2/M2 mixing ratio, = -0.0324(16)(17), is in close
agreement with the previous published average value = - 0.030(2), in
full confirmation of the presence of the irregular E2 admixture in the 501 keV
transition. The temperature dependence of the forward-backward asymmetry has
been measured over a more extended range of nuclear polarization than
previously possible, giving further evidence for parity mixing of the 8 and 8 levels and the deduced E2/M2 mixing ratio.Comment: 28 pages, 9 figures, accepted for publication in Physical Review
Functional cardiac MRI in preterm and term newborns.
Published versio
Solar Fusion Cross Sections
We review and analyze the available information for nuclear fusion cross
sections that are most important for solar energy generation and solar neutrino
production. We provide best values for the low-energy cross-section factors
and, wherever possible, estimates of the uncertainties. We also describe the
most important experiments and calculations that are required in order to
improve our knowledge of solar fusion rates.Comment: LaTeX file, 48 pages (figures not included). To appear in Rev. Mod.
Phys., 10/98. All authors now listed. Full postscript version with figures
available at http://www.sns.ias.edu/~jnb/Papers/Preprints/nuclearfusion.htm
Magnetic Moment of the Fragmentation Aligned 61Fe(9/2)+ Isomer
We report on the g factor measurement of the isomer in (). The isomer was produced and spin-aligned via a projectile-fragmentation
reaction at intermediate energy, the Time Dependent Perturbed Angular
Distribution (TDPAD) method being used for the measurement of the g factor. For
the first time, due to significant improvements of the experimental technique,
an appreciable residual alignment of the isomer has been observed, allowing a
precise determination of its g factor: . Comparison of the
experimental g factor with shell-model and mean field calculations confirms the
spin and parity assignments and suggests the onset of deformation due
to the intrusion of Nilsson orbitals emerging from the .Comment: 4 figures. Submitted to Phys. Rev. Let
Legal geographies of irregular migration : An outlook on immigration detention
In this article, I discuss legal geographies of irregular migration, drawing on a case study on immigration detention in Finland. Based on analysis of detention records, four different types of legal geographies are identified, relating to south–north movement of third‐country nationals inside Europe, criminalised Eastern European EU citizens, irregularity during the asylum process (in particular, related to the Dublin Regulation) and irregularly residing foreign nationals, including deportable long‐term residents. The analysis focuses on the relations between space, law and persons during detainees' irregular migration trajectories, paying attention to their varying entry routes, residence times, legal grounds for removal and detention and removal countries. I argue for the need for empirically contextualised analysis that addresses the complex relations between law and geography beyond a particular national context, in order to better understand the dynamics of irregular migration in all its variety.In this article, I discuss legal geographies of irregular migration, drawing on a case study on immigration detention in Finland. Based on analysis of detention records, four different types of legal geographies are identified, relating to south–north movement of third‐country nationals inside Europe, criminalised Eastern European EU citizens, irregularity during the asylum process (in particular, related to the Dublin Regulation) and irregularly residing foreign nationals, including deportable long‐term residents. The analysis focuses on the relations between space, law and persons during detainees' irregular migration trajectories, paying attention to their varying entry routes, residence times, legal grounds for removal and detention and removal countries. I argue for the need for empirically contextualised analysis that addresses the complex relations between law and geography beyond a particular national context, in order to better understand the dynamics of irregular migration in all its variety.Peer reviewe
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