3,880 research outputs found
Standard Model Electroweak Measurements at LEP
The current status of electroweak physics results from LEP is reviewed.
Particular emphasis is placed on the latest results on the properties of the Z
and W bosons. The updated status of the global electroweak fit to the standard
model and the resulting standard model Higgs mass limits are presented.Comment: 8 pages, 6 figures, contribution to the Proceedings of XLI Rencontres
de Moriond, Electroweak Interactions and Unified Theories, 11th - 18th March
2006, La Thuile, Ital
Type-II super-Backlund transformation and integrable defects for the N=1 super sinh-Gordon model
A new super-Backlund transformation for the N=1 supersymmetric sinh-Gordon
equation is constructed. Based on this construction we propose a type-II
integrable defect for the supersymmetric sinh-Gordon model consistent with this
new transformation through the Lagrangian formalism. Explicit expressions for
the modified conserved energy, momentum and supercharges are also computed. In
addition, we show for the model that the type-II defect can also been regarded
as a pair of fused defects of a previously introduced type. The explicit
derivation of the associated defect matrices is also presented as a necessary
condition for the integrability of the model.Comment: Latex 31 pages. Version accepted for publicatio
N=1 super sinh-Gordon model with defects revisited
The Lax pair formalism is considered to discuss the integrability of the N=1
supersymmetric sinh-Gordon model with a defect. We derive associated defect
matrix for the model and construct the generating functions of the modified
conserved quantities. The corresponding defect contributions for the modified
energy and momentum of the model are explicitly computed.Comment: Latex 26 page
Statistics of low-energy levels of a one-dimensional weakly localized Frenkel exciton: A numerical study
Numerical study of the one-dimensional Frenkel Hamiltonian with on-site
randomness is carried out. We focus on the statistics of the energy levels near
the lower exciton band edge, i. e. those determining optical response. We found
that the distribution of the energy spacing between the states that are well
localized at the same segment is characterized by non-zero mean, i.e. these
states undergo repulsion. This repulsion results in a local discrete energy
structure of a localized Frenkel exciton. On the contrary, the energy spacing
distribution for weakly overlapping local ground states (the states with no
nodes within their localization segments) that are localized at different
segments has zero mean and shows almost no repulsion. The typical width of the
latter distribution is of the same order as the typical spacing in the local
discrete energy structure, so that this local structure is hidden; it does not
reveal itself neither in the density of states nor in the linear absorption
spectra. However, this structure affects the two-exciton transitions involving
the states of the same segment and can be observed by the pump-probe
spectroscopy. We analyze also the disorder degree scaling of the first and
second momenta of the distributions.Comment: 10 pages, 6 figure
Testicular cancer and sperm DNA damage: short- and long-term effects of antineoplastic treatment
The aim of this study was to investigate sperm DNA damage induced by chemo- and radiotherapy in patients with testicular cancer to provide data on the extent and persistence of nuclear damage that might affect individual reproductive potential. We evaluated pre- and post-antineoplastic treatment sperm DNA integrity, expressed as DNA Fragmentation Index (DFI), in a large caseload of testicular cancer patients by sperm chromatin structure assay. The mean total DFI for all patients at T0 was 18.0 ± 12.5%. Sperm chromatin profile was markedly impaired at T3 (27.7 ± 17.4%) and T6 (23.2 ± 15.3%), improving considerably at T12 and T24 (14.0 ± 8.9% and 14.4 ± 10.3%). After chemotherapy, we found a marked increase in DFI at T3 and T6 and a significant reduction at T12 and T24 in comparison with the baseline. In contrast, DFI increased at T3 and T6 after radiotherapy but the subsequent reduction was far less marked, reaching baseline values at T12 and T24. Finally, post-treatment DNA damage was not age or histotype dependent, but was more marked in the advanced stage of cancer. In this study, we showed that the chromatin profile may be affected in the months immediately following the end of the treatment, improving after 12-24 months. Our results thus indicate that post-treatment DNA damage is influenced both by the type and intensity of the therapy and by the pathological and clinical stage of the disease. © 2014 American Society of Andrology and European Academy of Andrology
Defects in the supersymmetric mKdV hierarchy via Backlund transformations
The integrability of the supersymmetric modified Korteweg
de-Vries (smKdV) hierarchy in the presence of defects is investigated through
the construction of its super B\"acklund transformation. The construction of
such transformation is performed by using essentially two methods: the
B\"acklund-defect matrix approach and the superfield approach. Firstly, we
employ the defect matrix associated to the hierarchy which turns out to be the
same for the supersymmetric sinh-Gordon (sshG) model. The method is general for
all flows and as an example we derive explicitly the B\"acklund equations in
components for the first few flows of the hierarchy, namely and .
Secondly, the supersymmetric extension of the B\"acklund transformation in the
superspace formalism is constructed for those flows. Finally, this super
B\"acklund transformation is employed to introduce type I defects for the
supersymmetric mKdV hierarchy. Further integrability aspects by considering
modified conserved quantities are derived from the defect matrix.Comment: 40 pages. Some comments and references added. Version accepted for
publication in JHE
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