533 research outputs found
Up-Down Unification just above the supersymmetric threshold
Large corrections to the quark mass matrices at the supersymmetric threshold
allow the theory to have identical Yukawa matrices in the superpotential. We
demonstrate that Up-Down unification can take place in a moderate quark-squark
alignment scenario with an average squark mass of the order 1 TeV and with
Comment: 12 pages, latex, two figure
Minimal Ten-parameter Hermitian Texture Zeroes Mass Matrices and the CKM Matrix
Hermitian mass matrices for the up and down quarks with texture zeroes but
with the minimum number of parameters, ten, are investigated. We show how these
{\em minimum parameter} forms can be obtained from a general set of hermitian
matrices through weak basis transformations. For the most simple forms we show
that one can derive exact and compact parametrizations of the CKM mixing matrix
in terms of the elements of these mass matrices (and the quark masses).Comment: 14 pages.Talk given by M.B. at the MRST 98, ``Towards the Theory of
Everything", Montr\'eal, 13-15 May 199
Inflammatory response in induced sputum mononuclear cells from patients with acute exacerbation of asthma.
Examination of sputum provides a direct method to investigate airway inflammation non-invasively in particular Th1 (IL-2, IFN-gamma) and Th2 (IL-4, IL-10) cytokine production. IL-2, IL-4, IL-10 and IFN-gamma cytokine were studied in induced sputum mononuclear cells of asthmatic patients. Sputum induction was performed on 10 patients and 10 normal controls. Basal and mitogen-stimulated cytokine production was determined in induced sputum T-cell culture. Supernatants were collected and assayed not only with specific ELISA but also with polymerase chain reaction (PCR) techniques. Data showed a significantly higher production of IL-10 by both the ELISA and the RT-PCR techniques in asthmatic patients compared with sputum mononuclear cells from healthy controls. IL-4 production was detected at a low level using the ELISA method in asthmatic patients. The RT-PCR analysis detected a significantly IL-4-mRNA expression in all asthmatic patients, compared with controls. Results of IL-10 and IL-4 mRNA expression were reproducible. We did not find any alteration in the expression of the type 1 derived cytokines (IL-2 and IFN-gamma) in asthmatic patients or in healthy controls. Our study showed a tendency of induced sputum mononuclear cells to express a Th2-like cytokine pattern in acute exacerbation of asthmatic patients, where IL-10 and IL-4 are synthesized in larger amounts. The combination of sputum induction as a non-invasive tool to explore the lung and the identification of disease-associated cytokine expression and of specific cytokine mRNA should help elucidate mechanisms of the immunologically mediated inflammatory responses in asthma
The limits on CP-odd four-fermion operators containing strange quark field
The bounds on the neutron electric dipole moment and T-odd nucleon-nucleon
interaction are used to extract the limits on the effective CP-odd four-fermion
operators containing strange quark field. This completes the study of the
dim=5,6 CP-odd operators built from the light-quark fields. The limits are very
strong and comparable to those obtained previously for operators containing up
and down flavors. We also analyze the shift of the axionic vacuum,
, induced by four-fermion operators in the presence of PQ
mechanism and conclude that this gives subleading contributions to CP-odd
observables as compared with the direct ones.Comment: 10 pages. Standard Latex. 1 eps figur
Interleukin-6 in peripheral blood and inflammatory sites in Behçet's disease
Interleukin-6, a potent pro-inflammatory cytokine, might be involved in Behçet's disease (BD) pathological pathways. We investigated IL-6 levels in sera and synovial fluids collected from BD patients. The IL-6 production was also studied in vivo, by measuring its activity in culture supernatants of PBMC and alveolar macrophages, stimulated or not with LPS. The patients with BD were compared to RA patients and healthy controls. High IL-6 levels were observed in sera, synovial fluid and LPS stimulated PBMC supernatants, from active BD patients, similar to those of RA patients. Alveolar macrophages production of IL-6 was significantly elevated in two active BD patients with an interstitial pneumonia, when compared to controls. These elevated levels of IL-6 suggest its involvement in the inflammatory sites of BD, which may be related to the progression of the acute lesions, at least in the joints and in the lungs
Pure electroweak mechanism for the electric dipole moment of neutron in the Kobayashi-Maskawa model
The pure electroweak three-loop mechanism for the induced electric and
chromoelectric dipole moments of quarks is studied in the Kobayashi-Maskawa
model with three and four generations. In the standard three generation case,
this mechanism is found to produce a negligible contribution to the electric
dipole moment of neutron. In the presence of the fourth heavy generation,
however, pure electroweak corrections are important and might be several times
larger than the corresponding QCD contribution for the masses of heaviest
quarks 500-600 GeV. The resulting electric dipole moment of neutron
naturally arises at the level of . The effects of the
fourth generation physics are parametrized at standard electroweak scale by the
presence of the effective charged right-handed currents.Comment: 6 pages, LATeX file, 4 figures available upon reques
Constrained MSSM and the electric dipole moment of the neutron
We study the constraints on the CP-violating soft-breaking phases in the
minimal supersymmetric standard model using the limits on the chromoelectric
dipole moment of the strange quark extracted from the neutron EDM experiment.
Our investigation shows that the phase mediated by the gluino exchange diagram
has to be very small, , for the common supersymmetric mass
of the order of 100 GeV. Then, solving the renormalization group equations
analytically by iterations, we calculate the electric dipole moment of the
neutron in the MSSM with CP-conserving soft-breaking parameters for the case of
three and four generations. For the three-generation case we resolve the
apparent discrepancies between order-of-magnitude estimates and numerical
calculations existing in the literature. In this case the EDM of the neutron
does not exceed . For the four-generation case we show that
there is a significant enhancement which renders the EDM of the neutron at a
measurable level of .Comment: 18 pages, LaTex, 2 fig
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