1,106 research outputs found
Symmetry and Supersymmetry in Nuclear Pairing: Exact Solutions
Pairing plays a crucial role in nuclear spectra and attempts to describe it
has a long history in nuclear physics. The limiting case in which all single
particle states are degenerate, but with different s-wave pairing strengths was
only recently solved. In this strong coupling limit the nuclear pairing
Hamiltonian also exhibits a supersymmetry. Another solution away from those
limits, namely two non-degenerate single particle states with different pairing
strengths, was also given. In this contribution these developments are
summarized and difficulties with possible generalizations to more single
particle states and d-wave pairing are discussed.Comment: 6 pages of LATEX, to be published in the Proceedings of the "10th
Int. Spring Seminar on Nuclear Physics: New Quests in Nuclear Structure",
Vietri Sul Mare, May 21-25, 201
Supersymmetry and Nuclear Pairing
We show that nuclear pairing Hamiltonian exhibits supersymmetry in the
strong-coupling limit. The underlying supersymmetric quantum mechanical
structure explains the degeneracies between the energies of the N and Nmax-N+1
pair eigenstates. The supersymmetry transformations connecting these states are
given.Comment: 4 pages of REVTEX, one figur
Neutrinos and Symmetries
Three facets of symmetries in neutrino physics are briefly reviewed: i) The
SO(5) symmetry of the neutrino mass and and its connection to the see-saw
mechanism; ii) Flavor SU(N) symmetries of dense, self-interacting neutrino
gases in astrophysical settings; iii) The neutrino mixing angle theta13 and
possible CP-violation in the neutrino sector.Comment: 5 pages of LATEX; to appear in the proceedings 4th International
Symposium on Symmetries in Subatomic Physics held on June 2-5, 2009 at
Department of Physics, National Taiwan University, Taipei, Taiwa
Neutrino interactions in astrophysics and the third neutrino mixing angle theta13
The third neutrino mixing angle theta13 is the least known one. In this
contribution, after a brief discussion of the current efforts to determine the
value of this angle better, various astrophysical implications of a non-zero
value of theta13 are summarized.Comment: 6 pages, Proceedings of OMEG10 Symposium, Osaka, Japa
Partition Functions in Statistical Mechanics, Symmetric Functions, and Group Representations
Partition functions for non-interacting particles are known to be symmetric
functions. It is shown that powerful group-theoretical techniques can be used
not only to derive these relationships, but also to significantly simplify
calculation of the partition functions for particles that carry internal
quantum numbers. The partition function is shown to be a sum of one or more
group characters. The utility of character expansions in calculating the
partition functions is explored. Several examples are given to illustrate these
techniques.Comment: 16 pages of RevTe
A Semiclassical Approach to Level Crossing in Supersymmetric Quantum Mechanics
Much use has been made of the techniques of supersymmetric quantum mechanics
(SUSY QM) for studying bound-state problems characterized by a superpotential
. Under the analytic continuation , a pair of
superpartner bound-state problems is transformed into a two-state
level-crossing problem in the continuum. The description of matter-enhanced
neutrino flavor oscillations involves a level-crossing problem. We treat this
with the techniques of supersymmetric quantum mechanics. For the benefit of
those not familiar with neutrino oscillations and their description, enough
details are given to make the rest of the paper understandable. Many other
level-crossing problems in physics are of exactly the same form. Particular
attention is given to the fact that different semiclassical techniques yield
different results. The best result is obtained with a uniform approximation
that explicitly recognizes the supersymmetric nature of the system.Comment: 15 pages, Latex with lamuphys and psfig macros. Talk by first Author
at the UIC "Supersymmetry and Integrable Models Workshop", Chicago, June
12-14, 1997; proceedings to be published in Springer Lecture Notes in
Physics, H. Aratyn et al., eds. This paper also available at
http://nucth.physics.wisc.edu/preprint
Overview of Neutrino-Nucleus Interactions
An overview of neutrino-nucleus interactions is presented. After a brief
discussion of theory and applications of detector response three examples are
discussed: i) Recent work on neutrino-deuteron reactions, ii) Probing
strangeness content of the nucleon with neutrinos, and iii) The role of
neutrino reactions in supernova dynamics and r-process nucleosynthesis.Comment: 10 pages, 4 figures; proceedings of the Yukawa International Seminar
2001 (YKIS01), Physics of Unstable Nuclei, November 5-10, 2001, Kyoto, Japa
Neutrino Mixing and Oscillations in Astrophysical Environments
A brief review of the current status of neutrino mixing and oscillations in
astrophysical environments, with particular emphasis on the Sun and
core-collapse supernovae, is given. Implications of the existence of sterile
states which mix with the active neutrinos are discussed.Comment: Proceedings of the OMEG12 Conference, Tsukuba, Japa
Symmetries of Neutrino Physics
In this contribution to the proceedings of a conference honoring the career
of Francesco Iachello, two applications of symmetry principles to neutrino
physics are described. These applications are the connection between fermion
pairing in many-body physics and the neutrino mass as well as collective
neutrino oscillationsComment: 7 pages, Proceedings of the conference "SYMMETRIES AND ORDER:
Algebraic Methods in Many Body Systems
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