9,775 research outputs found
Full major-shell calculation for states that were degenerate in a single-j-shell calculation
A full fp calculation is performed for states which were degenerate in a
single-j-shell calculation in which isospin-zero two-body matrix elements were
set to zero energy. Most of the splitting in a complete shell calculation (but
not all) comes from the T=0 part of the interaction.Comment: 5 pages, RevTeX4. Submitted to Physical Review
Ratio of Isoscalar to Isovector Core Polarization for Magnetic Moments
In calculations of isoscalar magnetic moments of odd-odd N=Z nuclei it was
found that for medium to heavy mass nuclei large scale shell model calculations
yielded results which were very close to much simpler single j shell ones. To
understand this we compare isoscalar and isovector configuration mixing in
first order perturbation theory using a spin dependant delata interaction.The
isoscalar corrections are much smalle
Companion problems in quasispin and isospin
We note that the same mathematical results apply to problems involving
quasispin and isospin, but the problems per se are different. In the quasispin
case, one deals with a system of identical fermions (e.g. neutrons) and address
the problem of how many seniority conserving interactions there are. In the
isospin case, one deals with a system of both neutrons and protons and the
problem in question is the number of neutron-proton pairs with a given total
angular momentum. Other companion problems are also discussed.Comment: 12 pages, Latex; some additions in section II and a brief summary at
the en
Degeneracies when only T=1 two-body interactions are present
In the nuclear f_7/2 shell, the nucleon-nucleon interaction can be
represented by the eight values E(J)=,
J=0,1,...,7, where for even J the isospin is 1, and for odd J it is 0. If we
set the T=0 (odd J) two-body matrix elements to 0 (or to a constant), we find
several degeneracies which we attempt to explain in this work. We also give
more detailed expressions than previously for the energies of the states in
question. New methods are used to explain degeneracies that are found in {45}Ti
(I=25/2- and 27/2-), {46}V (I=12^+_1 and 13^+_1, as well as I=13^+_2 and 15+),
and {47}V (I=29/2- and 31/2-).Comment: 21 pages; RevTeX4. We have filled in some holes, mainly including
more equations for the 44Ti Sectio
Anomalies and Hawking radiation from the Reissner-Nordstr\"om black hole with a global monopole
We extend the work by S. Iso, H. Umetsu and F. Wilczek [Phys. Rev. Lett. 96
(2006) 151302] to derive the Hawking flux via gauge and gravitational anomalies
of a most general two-dimensional non-extremal black hole space-time with the
determinant of its diagonal metric differing from the unity () and use it to investigate Hawking radiation from the Reissner-Nordstrom
black hole with a global monopole by requiring the cancellation of anomalies at
the horizon. It is shown that the compensating energy momentum and gauge fluxes
required to cancel gravitational and gauge anomalies at the horizon are
precisely equivalent to the -dimensional thermal fluxes associated with
Hawking radiation emanating from the horizon at the Hawking temperature. These
fluxes are universally determined by the value of anomalies at the horizon.Comment: 18 pages, 0 figure. 1 footnote and 4 new reference adde
Zeros of 6j Symbols:Atoms:Nuclei and Bosons
The same 6j symbols that explains the absence of a certain atomic state in LS
coupling also explain the absence of certain states for a system of bosons and
also for certain nuclear states in jj coupling
Back reaction, covariant anomaly and effective action
In the presence of back reaction, we first produce the one-loop corrections
for the event horizon and Hawking temperature of the Reissner-Nordstr\"om black
hole. Then, based on the covariant anomaly cancelation method and the effective
action technique, the modified expressions for the fluxes of gauge current and
energy momentum tensor, due to the effect of back reaction, are obtained. The
results are consistent with the Hawking fluxes of a (1+1)-dimensional blackbody
at the temperature with quantum corrections, thus confirming the robustness of
the covariant anomaly cancelation method and the effective action technique for
black holes with back reaction.Comment: 17 page
Shell-model test of the rotational-model relation between static quadrupole moments Q(2^+_1), B(E2)'s, and orbital M1 transitions
In this work, we examine critically the relation between orbital magnetic
dipole (scissors mode) strength and quadrupole deformation properties. Assuming
a simple K=0 ground state band in an even-even nucleus, the quantities Q(2^+_1)
(i.e., the static quadrupole moment) and B(E2)_{0_1 \to 2_1} both are described
by a single parameter--the intrinsic quadrupole moment Q_0. In the shell model,
we can operationally define Q_0(Static) and Q_0(BE2) and see if they are the
same. Following a brief excursion to the sd shell, we perform calculations in
the fp shell. The nuclei we consider ({44,46,48}Ti and {48,50}Cr) are far from
being perfect rotors, but we find that the calculated ratio
Q_0(Static)/Q_0(BE2) is in many cases surprisingly close to one. We also
discuss the collectivity of orbital magnetic dipole transitions. We find that
the large orbital B(M1) strength in {44}Ti relative to {46}Ti and {48}Ti cannot
be explained by simple deformation arguments.Comment: 12 pages, RevTeX4. Sections II (Quadrupole properties in the
sd-shell) and V (Random interaction studies) added. Minor changes throughout
the text and 48Cr added to present Table IV, as well as results for the
lowest 100 state
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