1,597 research outputs found
Soft CP violation in K-meson systems
We consider a model with soft CP violation which accommodate the CP violation
in the neutral kaons even if we assume that the Cabibbo-Kobayashi-Maskawa
mixing matrix is real and the sources of CP violation are three complex vacuum
expectation values and a trilinear coupling in the scalar potential. We show
that for some reasonable values of the masses and other parameters the model
allows to explain all the observed CP violation processes in the
- system.Comment: 19 pages, RevTeX 4. Minor modification
An Integrated Strategy for a Production Planning and Warehouse Layout Problem: Modeling and Solution Approaches
We study a real-world production warehousing case, where the company always faces the challenge to find available space for their products and to manage the items in the warehouse. To resolve the problem, an integrated strategy that combines warehouse layout with the capacitated lot-sizing problem is presented, which have been traditionally treated separately in the existing literature. We develop a mixed integer linear programming model to formulate the integrated optimization problem with the objective of minimizing the total cost of production and warehouse operations. The problem with real data is a large-scale instance that is beyond the capability of optimization solvers. A novel Lagrangian relax-and-fix heuristic approach and its variants are proposed to solve the large-scale problem. The preliminary numerical results from the heuristic approaches are reported
A new type of CP symmetry, family replication and fermion mass hierarchies
We study a two-Higgs-doublet model with four generalised CP symmetries in the
scalar sector. Electroweak symmetry breaking leads automatically to spontaneous
breaking of two of them. We require that these four CP symmetries can be
extended from the scalar sector to the full Lagrangian and call this
requirement the principle of maximal CP invariance. The Yukawa interactions of
the fermions are severely restricted by this requirement. In particular, a
single fermion family cannot be coupled to the Higgs fields. For two fermion
families, however, this is possible. Enforcing the absence of flavour-changing
neutral currents, we find degenerate masses in both families or one family
massless and one massive. In the latter case the Lagrangian is highly
symmetric, with the mass hierarchy being generated by electroweak symmetry
breaking. Adding a third family uncoupled to the Higgs fields and thus keeping
it massless we get a model which gives a rough approximation of some features
of the fermions observed in Nature. We discuss a number of predictions of the
model which may be checked in future experiments at the LHC.Comment: 24 pages. Version published in EPJC. Minor changes as suggested by
the refere
CP properties of symmetry-constrained two-Higgs-doublet models
The two-Higgs-doublet model can be constrained by imposing Higgs-family
symmetries and/or generalized CP symmetries. It is known that there are only
six independent classes of such symmetry-constrained models. We study the CP
properties of all cases in the bilinear formalism. An exact symmetry implies CP
conservation. We show that soft breaking of the symmetry can lead to
spontaneous CP violation (CPV) in three of the classes.Comment: 14 pages, 2 tables, revised version adapted to the journal
publicatio
Phenomenological model of elastic distortions near the spin-Peierls transition in
A phenomenological model of the Landau type forms the basis for a study of
elastic distortions near the spin-Peierls transition in . The
atomic displacements proposed by Hirota {\it et al.} [Phys. Rev. Lett. {\bf
73}, 736 (1994)] are accounted for by the model which includes linear coupling
between and distortions. displacements are seen to be responsible
for anomalies in the elastic properties {\it at} , whereas incipient
distortions give rise to temperature dependence below . A discussion of
possible critical behavior is also made.Comment: 1 figure available upon reques
Fungal diversity in deep-sea sediments associated with asphalt seeps at the Sao Paulo Plateau
We investigated the fungal diversity in a total of 20 deep-sea sediment samples (of which 14 samples were associated with natural asphalt seeps and 6 samples were not associated) collected from two different sites at the Sao Paulo Plateau off Brazil by Ion Torrent PGM targeting ITS region of ribosomal RNA. Our results suggest that diverse fungi (113 operational taxonomic units (OTUs) based on clustering at 97% sequence similarity assigned into 9 classes and 31 genus) are present in deep-sea sediment samples collected at the Sao Paulo Plateau, dominated by Ascomycota (74.3%), followed by Basidiomycota (11.5%), unidentified fungi (7.1%), and sequences with no affiliation to any organisms in the public database (7.1%). However, it was revealed that only three species, namely Penicillium sp., Cadophora malorum and Rhodosporidiwn diobovatum, were dominant, with the majority of OTUs remaining a minor community. Unexpectedly, there was no significant difference in major fungal community structure between the asphalt seep and non-asphalt seep sites, despite the presence of mass hydrocarbon deposits and the high amount of macro organisms surrounding the asphalt seeps. However, there were some differences in the minor fungal communities, with possible asphalt degrading fungi present specifically in the asphalt seep sites. In contrast, some differences were found between the two different sampling sites. Classification of OTUs revealed that only 47 (41.6%) fungal OTUs exhibited >97% sequence similarity, in comparison with pre-existing ITS sequences in public databases, indicating that a majority of deep-sea inhabiting fungal taxa still remain undescribed. Although our knowledge on fungi and their role in deep-sea environments is still limited and scarce, this study increases our understanding of fungal diversity and community structure in deep-sea environments.Japan Society for the Promotion of ScienceJapan Agcy Marine Earth Sci & Technol, 2-15 Natsushima Cho, Yokosuka, Kanagawa 2370061, JapanUniv Vale Itajal, Dept Biol Sci, CTTMar, R Uruguai 458, BR-88302202 Itajal, SC, BrazilUniv Fed Sao Paulo, Rua Prof Artur Riedel 275, BR-09972270 Diadema, SP, BrazilUniv Sao Paulo, Inst Oceanog, 191 Praca Oceanog, BR-05508120 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Rua Prof Artur Riedel 275, BR-09972270 Diadema, SP, BrazilJSPS: 23770098JSPS: 15K18601Web of Scienc
Clinical Pathological Analysis of Surgically Resected Superficial Esophageal Carcinoma to Determine Criteria for Deciding on Treatment Strategy
We performed a clinical pathological study of conventionally resected superficial esophageal carcinomas since this type of lesion has been increasing, in order to develop criteria of determination for therapeutic strategies. Pathological studies were performed on specimens obtained by radical surgical resection in 133 cases of superficial esophageal cancer. Evaluation was performed in terms of the gross classification of the lesion type, depth of invasion, lymph node metastasis, vascular invasion, size of the lesion, outcome, etc. In 0-I, 0-IIc+0-IIa, and 0-III type submucosal cancer lesions the rate of metastasis to lymph nodes was more than 40%, but in 0-IIa and 0-IIb mucosal cancer cases no lymph node metastasis was observed. 0-IIc type lesions showed a wide range of invasiveness, ranging from m1 to sm3. In cases with m1 or m2 invasion, no lymph node or lymph-vessel invasion was recognized, but in m3, sm1, sm2, and sm3 cases lymph node metastasis was recognized in 12.5%, 22.2%, 44.0% and 47.4%, respectively. In 47% of lesions with a greatest dimension of less than 30 mm invasion was limited to the mucosa. Seventy-two percent of m1 and m2 cases were 30 mm in size or less. Lymph node metastasis was recognized in only 16.7% of cases less than 30 mm in size, but in cases of lesions 30 mm or more the rate of lymph node metastasis was 35.8%. 0-IIb and 0-IIa type lesions are indications for endoscopic esophageal mucosal resection (EEMR), while 0-I, 0-IIc+0-IIa, and 0-III lesions should be candidates for radical surgical resection. In the 0-IIc category, lesions in which the depression is relatively flat and with a finely granular surface are indications for EEMR, but those cases in which the surface of depression shows granules of varying sizes should be treated with radical surgical resection. Cases of 0-IIa type 30 mm or larger in greatest dimension which have a gently sloping protruding margin shoulder or reddening should be treated with caution, but EEMR can be performed first and subsequent therapeutic strategy decided on, based on the pathological findings of the specimen
- …