6,031 research outputs found
SU(5) Symmetry of spdfg Interacting Boson Model
The extended interacting boson model with s-, p-, d-, f- and g-bosons being
included (spdfg IBM) are investigated. The algebraic structure including the
generators, the Casimir operators of the groups at the SU(5) dynamical symmetry
and the branching rules of the irreducible representation reductions along the
group chain are obtained. The typical energy spectrum of the Symmetry is given.Comment: 12 pages, 2 figure
Determination of mixing angle through decays
We study decays, the quark content of
and the mixing angle of and . We calculate not only the
factorizable contribution in QCD facorization scheme but also the
nonfactorizable hard spectator corrections in QCDF and pQCD approach. We get
consistent result with the experimental data of and
predict the branching ratio of . We suggest two ways
to determine mixing angle . Using the experimental
measured branching ratio of , we can get the
mixing angle with some theoretical uncertainties. We
suggest another way to determine mixing angle using both
of experimental measured decay branching ratios to avoid theoretical uncertainties.Comment: arXiv admin note: substantial text overlap with arXiv:0707.263
The study of decays and determination of mixing angle
We study decays and suggest two methods to
determine the mixing angle. We calculate not only the
factorizable contribution in QCD facorization scheme but also the
nonfactorizable hard spectator corrections in pQCD approach. We get the
branching ratio of which is consistent with recent
experimental data and predict the branching ratio of to be . Two methods for determining
mixing angle are suggested in this paper. For the first
method, we get the mixing angle to be about
, which is in consistency with others in the literature. The
second method depends on less parameters so can be used to determine the
mixing angle with better accuracy but needs, as an input,
the branching ratio for which should be measured in
the near future.Comment: 16pages,4figure
Knee joint kinematics before and after body weight change
Obesity is a well-defined mechanical factor for osteoarthritis (OA). More than one-third of adults in the United States are obese, and one in three obese adults has arthritis. In obese individuals, knee pain is highly prevalent and is often thought to be the first symptom of knee OA. In the pathomechanics of knee OA, altered kinematics and contact location in the knee joint are potent contributors to OA initiation and progression. However, such kinematics and cartilage contact location in obese individuals, and how the knee joint responses to excess load due to obesity are not clear and understudied, mainly limited by the instrumentations. Therefore, we conducted a series of dissertation studies to investigate the effect of weight on the knee joint kinematics in six degrees of freedom (6DOF) and cartilage contact location using a fluoroscopic imaging system with magnetic resonance-based morphological models. In Study 1, the 6DOF kinematic analysis showed that obese individuals with knee pain walked with a reduced range of flexion-extension motion and a reduced medial-lateral translation compared with non-obese controls. In Study 2, the cartilage contact analysis showed that obese individuals experienced different contact location on both the tibial and femoral cartilage surfaces during walking when compared with a healthy group, while pain had a minimal effect on the cartilage contact location. In Study 3, we followed up with the obese individuals in Study 1 and the kinematic analysis showed that the change in range of the flexion-extension and adduction-abduction motion during gait were associated with the change in body weight; however, knee pain was not associated with the kinematic change. In conclusion, this series of dissertation studies suggests that the kinematics of the knee in obese individuals with knee pain was modifiable through weight loss. Weight management should be addressed more than controlling for pain in obese individuals with pain, as pain management might not able to restore the contact locations.2020-07-06T00:00:00
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