Modified Higgs couplings and unitarity violation

Prompted by the recent observation of a Higgs-like particle at the CERN Large Hadron Collider (LHC), we investigate a quantitative correlation between possible departures of the gauge and Yukawa couplings of this particle from their Standard Model expectations and the scale of unitarity violation in the processes $WW \to WW$ and $t\bar t \to WW$.Comment: 6 pages, 6 eps figures, Arrayeq.sty attached; v2: minor updates, version published: PRD 87 (2013) 011702(R), Rapid Communicatio

S3S_3 symmetry and the quark mixing matrix

We impose an $S_3$ symmetry on the quark fields under which two of three quarks transform like a doublet and the remaining one as singlet, and use a scalar sector with the same structure of $SU(2)$ doublets. After gauge symmetry breaking, a $\mathbb{Z}_2$ subgroup of the $S_3$ remains unbroken. We show that this unbroken subgroup can explain the approximate block structure of the CKM matrix. By allowing soft breaking of the $S_3$ symmetry in the scalar sector, we show that one can generate the small elements, of quadratic or higher order in the Wolfenstein parametrization of the CKM matrix. We also predict the existence of exotic new scalars, with unconventional decay properties, which can be used to test our model experimentally.Comment: 7 pages, no figur

Confined Energy State Based Hypothetical Observations about Device Parameters of AlGaN / GaN HEMT

In this paper, the gate threshold voltage of AlGaN / GaN HEMT devices has been analytically predicted based on the calculated energy levels inside triangular quantum well at the hetero-interface and found to be comparable with experimental data. The conceptual explanation of device linearity in large signal applications has been presented in terms of quantized energy levels in the quantum well. The dependence of threshold voltage and linear operable gate voltage range on a newly introduced parameter named “Surface Factor” is analyzed as well

Derivational Morphology of Assamese Lexical Word Categories

Word formation by derivation is very productive in Assamese. A significant amount of words in Assamese owe their origin to derivation. The analysis in this paper takes into account the derivational processes related with lexical word categories, and, numerous bound morphemes that are used in the derivational process in the language. This analysis helps us to understand some of the important aspects of Assamese morphology. These aspects are - role of class maintaining and class changing morphemes, derivation of word from synonyms, productivity of derivational morphemes, morphophonemic changes in root as a result of affixation of derivational morphemes, presence of allomorphs of various bound morphemes, ability of a morpheme to derive words from different word categories. The significance of this papers lies in the fact that  these  word formation processes could help develop morphological rules that can be used for developing computational morphological tools like- stemmer, spell checker, tagger etc

Gate leakage current reduction with advancement of graded barrier AlGaN/GaN HEMT

The gate leakage current reduction solution of AlGaN/GaN HEMT device issue has been addressed in this paper with compositional grading of AlGaN barrier layer. This work is also conjugated with the critical thickness limitation of heterostructure material growth. Hence, critical thickness calculation of AlGaN over GaN has been kept in special view. 1D Schrodinger and Poisson solver was used to calculate the 2DEG concentration and effective location to use it in the ATLAS device simulator for the predictions. The proposed Al0.50Ga0.50N/Al0.35Ga0.65N /Al0.20Ga0.80N/GaN HEMT structure exhibits the leakage current of the order of around 15 nA/mm at gate voltage of 1 V. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2789

Scalar sector properties of two-Higgs-doublet models with a global U(1) symmetry

We analyze the scalar sector properties of a general class of two-Higgs-doublet models which has a global U(1) symmetry in the quartic terms. We find constraints on the parameters of the potential from the considerations of unitarity of scattering amplitudes, the global stability of the potential and the $\rho$-parameter. We concentrate on the spectrum of the non-standard scalar masses in the decoupling limit which is preferred by the Higgs data at the LHC. We exhibit charged-Higgs induced contributions to the diphoton decay width of the 125\,GeV Higgs boson and its correlation with the corresponding $Z\gamma$ width.Comment: 12 pages, 15 eps figure files; minor modifications made and a few references adde

An S3S_3 flavored left-right symmetric model of quarks

We construct a model based on the electroweak gauge group $\rm SU(2)_L \times SU(2)_R \times U(1)_{B-L}$ augmented by an $S_3$ symmetry. We assign nontrivial $S_3$ transformation properties to the quarks and consequently we need two scalar bidoublets. Despite the extra bidoublet we have only six Yukawa couplings thanks to the discrete symmetry. Diagonalization of the quark mass matrices shows that at the leading order only the first two generations mix, resulting in a block diagonal CKM matrix, and the first generation quarks are massless. Inclusion of subleading terms produce an acceptable CKM matrix up to corrections of order $\lambda^4$. As for the first generation quark masses, we obtain satisfactory value of $m_u/m_d$. The masses themselves, though being in the same ballpark, turn out to be somewhat smaller than the accepted range.Comment: 12 pages, 1 colored figur

Duplex electroless Ni-P/Ni-Cu-P coatings: Preparation, evaluation of microhardness, friction, wear, and corrosion performance

The current study focuses on the development of duplex Ni-P/Ni-Cu-P coatings by the electro­less deposition method. Coatings are developed on mild steel substrates with Ni-Cu-P as the outer layer and Ni-P as the inner layer and vice versa. The coated samples are heat-treated at temperatures ranging between 200 to 800 °C during 1 and 4 h. Coated samples are characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The effect of heat treatment tempera­ture and its time duration on the hardness, friction and wear behaviour of both coatings are evaluated and compared. This would help in understanding how heat treatment influences the duplex system of coatings and helps in identifying the suitable condition of heat treatment for optimal performance of the coating. It is observed that heat treatment has a positive influence over the coating performance, which is the best when treated under optimal temperature and time duration conditions. The corrosion behaviour of the coatings is also assessed with the help of electrochemical techniques, viz. potentiodynamic polari­zation and electrochemical impedance spectroscopy. The results show that the duplex coat­ings can provide substantial protection to the mild steel substrates. Heat treatment is also found to have a significant influence on the corrosion behaviour of duplex coatings

Strategic review of arsenide, phosphide and nitride mosfets

Metal oxide semiconductor field effect transistor used as an amplifier and switch uses Si primarily as a channel material for its very stable oxide SiO2. In-spite of many advantages there are some restrictions for Si MOS, so the world is approaching towards compound semiconductor for higher frequency and current. The development of compound semiconductor metal oxide semiconductor is also facing critical problems due to the lack of availability of proper gate oxide material. Research is being conducted on arsenide and phosphide metal oxide semiconductor field effect transistor. Nitride channel MOS are in focus due to their high band gap, high current and high temperature uses. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2208