12,919 research outputs found
mixing in the minimal flavor-violating two-Higgs-doublet models
The two-Higgs-doublet model (2HDM), as one of the simplest extensions of the
Standard Model (SM), is obtained by adding another scalar doublet to the SM,
and is featured by a pair of charged scalars, which could affect many
low-energy processes. In the "Higgs basis" for a generic 2HDM, only one scalar
doublet gets a nonzero vacuum expectation value and, under the criterion of
minimal flavor violation, the other one is fixed to be either color-singlet or
color-octet, which are named as the type-III and the type-C 2HDM, respectively.
In this paper, we study the charged-scalar effects of these two models on the
mixing, an ideal process to probe New Physics (NP) beyond the
SM. Firstly, we perform a complete one-loop computation of the box diagrams
relevant to the mixing, keeping the mass and momentum of the
external strange quark up to the second order. Together with the up-to-date
theoretical inputs, we then give a detailed phenomenological analysis, in the
cases of both real and complex Yukawa couplings of the charged scalars to
quarks. The parameter spaces allowed by the current experimental data on the
mass difference and the CP-violating parameter are
obtained and the differences between these two 2HDMs are investigated, which
are helpful to distinguish them from each other from a phenomenological point
of view.Comment: 30 pages,10 figures, 2 table
Codonopsis pilosula twines either to the left or to the right
We report the twining handedness of Codonopsis pilosula, which has either a left- or right-handed helix among different plants, among different tillers within a single plant, and among different branches within a single tiller. The handedness was randomly distributed among different plants, among the tillers within the same plants, but not among the branches within the same tillers. Moreover, the handedness of the stems can be strongly influenced by external forces, i.e. the compulsory left and right forming inclined to produce more left- and right-handed twining stems, respectively, and the reversing could make a left-handed stem to be right-handed and vice versa. We also discuss the probable mechanisms these curious cases happen
Hemiaquabis(2-fluorobenzoato-κ2 O,O′)bis(1,10-phenanthroline-κ2 N,N′)lead(II) dihydrate
In the title compound, [Pb(C7H4FO2)2(C12H8N2)2(H2O)0.5]·2H2O, the PbII atom is coordinated by four N atoms from two bidentate chelating 1,10-phenanthroline (phen) ligands, four O atoms from two 2-fluorobenzoate ligands and a half-occupied water molecule in an irregular coordination geometry. One carboxylate O atom and two F atoms are each disordered over two sites with occupancy factors of 0.558 (6) and 0.442 (6). The two crystallographically independent phen ligands are co-planar [dihedral angle 0.0 (2)°]. Centroid–centroid distances of 3.659 (7) and 3.687 (7) Å indicate π–π stacking interactions between neighboring phen ligands. In the crystal, O—H⋯O, C—H⋯F and C—H⋯O hydrogen bonds link the complex molecules and uncoordinated water molecules into a supramolecular network
PIWI-interacting RNAs: Mitochondria-based biogenesis and functions in cancer
PIWI-interacting RNA (piRNAs), once thought to be mainly functioning in germlines, are now known to play an essential role in somatic and cancerous tissues. Ping-pong cycle initiation and mitochondria-based phased production constitute the core of the piRNA biogenesis and these two processes are well conserved in mammals, including humans. By being involved in DNA methylation, histone marker deposition, mRNA degradation, and protein modification, piRNAs also contribute to carcinogenesis partly due to oncogenic stress-induced piRNA dysregulation. Also, piRNAs play important roles in cancer stemness, drug resistance, and tumor immunology. Results from liquid biopsy analysis of piRNA can be used in both cancer diagnoses and cancer prognoses. A combination of targeting piRNA with other therapeutic strategies could be groundbreaking cancer treatment
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