SM Model Research Articles

On dark matter selected high-scale supersymmetry

The prediction for the Higgs mass in the dark matter selected high-scale SUSY is explored. We show the bounds on SUSY-breaking scale in models of SM $+\tilde{w}$ and SM $+\tilde{h}/\tilde{s}$ due to the observed Higgs mass at the LHC. We propose that effective theory below scale $\tilde{m}$ described by SM $+\tilde{w}$ is possibly realized in gauge mediation with multiple spurion fields that exhibit significant mass hierarchy, and that by SM $+\tilde{h}/\tilde{s}$ can be realized with direct singlet-messenger-messenger coupling for singlet Yukawa coupling $\lambda\sim(v/\tilde{m})^{1/2}g_{\text{SM}}$. Finally, the constraint on high-scale SUSY is investigated in the light of inflation physics if these two subjects are directly related.

The Mu3e Experiment at PSI

The Mu3e experiment will search for the lepton flavor violating neutrinoless muon decay μ+→e+e−e+ with a sensitivity down to 10−16 (90% C.L.) using the world most intense continuous muon beam at the Paul Scherrer Institute. This decay is strongly suppressed in the Standard Model (BR<10−56). Several Beyond the SM models predict observable effects accessible to the new generation of LFV experiments. The search for the μ+→e+e−e+ decay requires excellent momentum, spacial, and time resolution to suppress backgrounds, high rate capability (detect more than 109 stopped muons per second), and large acceptance. The required detector performance is possible thanks to tracking detectors based on thin monolithic active silicon pixel sensors with high granularity (HV-MAPS), which incorporate the complete read-out electronics on the sensor chip, and very precise timing measurements using scintillating fibers and tiles coupled to silicon photo-multipliers operating at very high particle rates.

Use of a synthesized mathematical model to describe the probability of curing early-stage breast cancer

Breast cancer (ВС) is a common malignant disease of the female reproductive system. Currently we have many treatment strategies given location depending on the clinical data. Radiation therapy is an important component in a comprehensive program of treatment for ВС. Despite the fact that often use a single dose fractionation regime 1.8–2 Gy daily fractions to a total of 50 Gy in 5 weeks, do not run out to try to find new modes of fractionation. According to published research results hypofractionated regimes, we can conclude that the approaches to the value of the dose per fraction, the number of fractions and the time of treatment differ. Dose per fraction ranged from 2.66 to 3.2 Gy, and more recently have been tested modes with a single dose of 6 Gy. Empirical data from these studies are important, but must also be aware of the possibility of applying mathematical methods for computing the probability of cure of the tumor and the occurrence of radiation complications. It is necessary for an individual approach to each patient, picking up for some clinical cases the optimal mode of fractionation. In addition, the search continues and improvement fractionation regimes, and the results of clinical trials can tell a lot about how good the chosen model. In work the opportunity of application of the synthesized mathematical model (SM model), intended for description of NTCP, to the description of probability of local treatment of early stages of the ВС.

Experiment and multiobjective optimization design of tape-spring hinges

Flexible tape-spring hinges can be folded elastically and are able to self-deploy by releasing stored strain energy with fewer component parts and slight weights. This study presents a detailed investigation of the folding and deployment of single-layer tape-spring (SLTS) hinges and double-layer tape-spring (DLTS) hinges under pure bend loading. The material properties of tape-spring hinges are measured using an INSTRON machine. A DLTS hinge construction is created, and its moment-rotation relationship during quasi-static deployment is measured. An experiment is conducted to verify the validation of the numerical models for the DLTS hinges. The quasi-static deployment behavior of SLTS hinges and DLTS hinges is then analyzed using nonlinear finite element ABAQUS/Explicit solver, starting from the complete folded configuration. The DLTS hinge has good quasi-static deployment performances with regard to maximum stress (Sm), steady moment (M*) and the peak moment (Md) during the DLTS hinge quasi-static deployment. In addition, the sampling designs of the DLTS hinges are created based on a three-level full factorial design of experiments (DOE) method. The surrogate models of Sm, M* and Md of the DLTS hinges are derived using response surface method (RSM) to reduce the computational cost of quasi-static folding and deployment of numerical simulations. The Multiobjective optimization design (MOD) of the DLTS hinge is performed using modified non-dominated sorting genetic algorithm (NSGA-II) algorithm to achieve the optimal design. The finite element models for the optimal design based on numerical method are established to validate the optimization results.

Comparison of three longitudinal analysis models for the health-related quality of life in oncology: a simulation study.

BackgroundHealth-Related Quality of Life (HRQoL) is an important endpoint in oncology clinical trials aiming to investigate the clinical benefit of new therapeutic strategies for the patient. However, the longitudinal analysis of HRQoL remains complex and unstandardized. There is clearly a need to propose accessible statistical methods and meaningful results for clinicians. The objective of this study was to compare three strategies for longitudinal analyses of HRQoL data in oncology clinical trials through a simulation study.MethodsThe methods proposed were: the score and mixed model (SM); a survival analysis approach based on the time to HRQoL score deterioration (TTD); and the longitudinal partial credit model (LPCM). Simulations compared the methods in terms of type I error and statistical power of the test of an interaction effect between treatment arm and time. Several simulation scenarios were explored based on the EORTC HRQoL questionnaires and varying the number of patients (100, 200 or 300), items (1, 2 or 4) and response categories per item (4 or 7). Five or 10 measurement times were considered, with correlations ranging from low to high between each measure. The impact of informative missing data on these methods was also studied to reflect the reality of most clinical trials.ResultsWith complete data, the type I error rate was close to the expected value (5%) for all methods, while the SM method was the most powerful method, followed by LPCM. The power of TTD is low for single-item dimensions, because only four possible values exist for the score. When the number of items increases, the power of the SM approach remained stable, those of the TTD method increases while the power of LPCM remained stable. With 10 measurement times, the LPCM was less efficient. With informative missing data, the statistical power of SM and TTD tended to decrease, while that of LPCM tended to increase.ConclusionsTo conclude, the SM model was the most powerful model, irrespective of the scenario considered, and the presence or not of missing data. The TTD method should be avoided for single-item dimensions of the EORTC questionnaire. While the LPCM model was more adapted to this kind of data, it was less efficient than the SM model. These results warrant validation through comparisons on real data.Electronic supplementary materialThe online version of this article (doi:10.1186/s12955-014-0192-2) contains supplementary material, which is available to authorized users.

Incorporation of the Stefan-Maxwell Multicomponent Diffusion Model into a Pore Network Model of the PEMFC Electrode

Polymer electrolyte membrane fuel cells are one of the best candidates to replace internal combustion engines. The key requirement for commercial success of PEMFCs is to demonstrate optimal performance at high current density. However, because of liquid water generation, the power density is reduced by mass transport limitations at the cathode. Accordingly, precise modeling of mass transfer inside the porous structure of fuel cell electrodes is crucial. Ordinary diffusion is the most commonly considered diffusion model for PEMFC in the literature. In most of these studies, the gas transport is considered as a binary system of oxygen diffusing through nitrogen (and sometimes water vapor). However, realistic simulation of fuel cell operation requires simultaneous modeling of both oxygen and water vapor transport in a stagnant film of nitrogen. In multicomponent diffusion, the fluxes of all of the species are important to consider since they might affect the diffusive transport of the other species. A pore network modeling has been developed using the Stefan-Maxwell approach, to simulate the diffusion of gases mixtures inside fuel cell electrodes. Pore network models (PNM) provide an alternative approach for the continuum modeling in porous media. Rather than using finite element models of transport in the pore space, PNMs use pore-to-pore nodal balances to model species transport. They also enable the structural properties of the porous material to be incorporated directly into the model, rather than through constitutive relationships. The SM model is notoriously difficult to solve numerically for pore networks, but some simplifications and solution schemes have been proposed in the literature [1,2] based on decomposing Jacobian matrix of the equations, which are less computationally expensive. In this work, these methods have been evaluated to determine an appropriate solution algorithm for the pore network. These advantages come at the expense of rigorous transport phenomena calculations since some simplification to the SM model are made.

A Comprehensive Elastic-Plastic Single-Asperity Contact Model

Generally, the contact of rough surfaces is modeled and analyzed through statistical approaches, including microgeometrical measurements and description of the asperities in contact (shape, size, spacing, and asperity height), developing theoretical expressions to describe the mechanical behavior of the asperities in contact, and finally extending it to the whole surface contacts. In some of the main contact models like the Kogut-Etsion model (KE model), Jackson-Green model (JG model), and Shankar-Mayuram model (SM model), an axisymmetrical hemispherical asperity in contact with a rigid flat surface is modeled and analyzed using finite element concepts and the resultant contact parameter relations are extended to rough surface contacts. The present work addresses the complete effect of Poisson's ratio and its influence in sub surface yielding, elastic-plastic transition and inception of fully plastic contact by accounting realistic material behavior which are not covered by the above models. A unified single-asperity model is proposed and, based on the results, empirical relations are developed to predict the contact parameters (dimensionless contact load and contact area), which are then extended to statistical rough surface contacts.

A mechanistic study on the effect of a surface protecting agent on electrocrystallization of silver nanoparticles

Surface protecting agent slowed down the kinetics of electrocrystallization due to introduction of a higher activation overpotential at the electrode–electrolyte interface. The true density of AgNPs significantly differs from the calculated values from the SH, SM, SRWBS and HT models.

Effect of Strain Hardening during Unloading for an Elastic-Plastic Hemisphere in Contact with a Rigid Flat

Identifying the exact state transition, i.e., end of elastic-plastic regime or the start of fully plastic regime, in asperity level contacts during loading and unloading process requires much attention to prevent the failure of components. The present work extends the Shankar and Mayuram model (SM Model) work for the unloading case. An axisymmetrical hemispherical asperity in contact with a rigid flat is considered in the present analysis for the unloading case by including the strain hardening effect. The unloading is done accurately at the end of elastic-plastic state on the lines of SM model empirical expressions for various Y/E ratios, also with different Et /E ratios. New empirical expressions are formulated based on the extensive analysis to determine the residual interference ratio. The results are generalized at the end of the elastic-plastic state for different levels of Y/E ratios by including the strain hardening effect.

Experimental study on pathogenesis of syringomyelia

Objective To establish an animal model of SM in rabbits and research it's pathogenesis.Methods 16 rabbits were randomly divided into experimental group and control group,all animals were perfomed microsurgery via suboccipital midline approach.The core of pencil (diameter 0.5 mm,length 6 mm) was planted into spinal central canal via its opening in experimental group.MRI were carried out preoperation and 2,4,6,8 weeks after operation.All rabbits were executed after 8 weeks and spinal cord histological examinations were perfomed.Results The diameter of cervical spinal central canal were (0.505±0.046) mm in experimental group and (0.304 ±0.045) mm in control group,which have significance difference (t =8.787,P ＜ 0.05).The MRIT2 weighted sagittal films showed the linear high signal shadow at middle of cervical spinal cord 2 ～4 weeks after operation in experimental group and the linear high signal shadow became wider and longer in 6 ～ 8 weeks.Conclusion The SM model in rabbits were established successfully via mechanical obstruction of the opening of spinal central canal.The pathogenesis of SM pitients may be obstruction of the opening of spinal central canal caused by defferent kinds of elements. Key words: Syringomyelia; Chiari malformation; Central canal of spinal cord ; Animal model; Pathogenesis

Search for Resonance in the Dilepton Mass at LHC Using MC Simulation

In the present work we search for Resonance in the dielectron events produced in proton-proton collisions at LHC using Monte Carlo simulation programs which may be Z'_{B-L} heavy neutral boson. To detect this resonance at LHC we used the data which are produced fro m pp collision of Pythia8 produced events at different energ ies for LHC then we use the angular d istribution for the dielectron produced fro m Z'_{B-L} decay channels to detect the Z'_{B-L}signal. B-L extension of the SM model p redicts the existence of a Z'_ {B-L}heavy neutral massive boson at high energies and fro m our results which we had simu lated for Z'_{B-L}in the B-L extension of standard model we predict that a Z'_{B-L}boson will be found at LHC and has a mass in the range fro m 1 TeV to 1.5 TeV.

On the correlations between flavour observables in minimal U(2)3 models

The stringent correlations between flavour observables in models with CMFV are consistent with the present data except for the correlation Delta M_{s,d}-epsilon_K. Motivated by the recent work of Barbieri et al, we compare the CMFV correlations with the ones present in a special class of models with an approximate global U(2)^3 flavour symmetry, constrained by a minimal set of spurions governing the breakdown of this symmetry and the assumption that only SM operators are relevant in flavour physics. This analog of CMFV to be called MU(2)^3 allows to avoid the Delta M_{s,d}-epsilon_K tension in question because of reduced flavour symmetry and implied non-MFV contributions to Delta M_{s,d}. While the patterns of flavour violation in K meson system is the same as in CMFV models, the CP-violation in B_{s,d} meson systems can deviate from the one in the SM and CMFV models. We point out a stringent triple S_{psi K_S}-S_{psi phi}-|V_ub| correlation in this class of models that could in the future provide a transparent distinction between different MU(2)^3 models and in the context of these models determine |V_ub| by means of precise measurements of S_{psi K_S} and S_{psi phi} with only small hadronic uncertainties. For fixed S_{psi K_S} the correlation between B(B^+ -> tau^+nu_tau) and S_{psi phi} follows. We also find that MU(2)^3 models could in principle accommodate a negative value of S_{psi phi}, provided |V_ub| is found to be in the ballpark of exclusive determinations and the particular MU(2)^3 model provides a 25% enhancement of epsilon_K. A supersymmetric U(2)^3 model worked out in the Barbieri-School appears to satisfy these requirements. However if B(B^+ -> tau^+nu_tau)>1.0 10^{-4} will be confirmed by future experiments only positive S_{psi phi} is allowed in this framework. We summarize briefly the pattern of flavour violation in rare K and B_{s,d} decays in MU(2)^3 models.

Search for High Energy Electrons from New Neutral Massive Gauge Boson Decay in the CMS Detector at the LHC Using Monte Carlo Simulation

The existence of new heavy neutral massive boson Z′ is a feature of many extensions of Standard Model models as the two-Higgs-doublet model (2HDM), the Hidden Abelian Higgs Model (HAHM), Left-Right Symmetric Model (LRSM), Sequential Standard Model (SSM) and Baryon number minus Lepton number Model (B-L). In the present work we search for two high energy electrons produced from decayingheavy neutral massive boson in the events produced in proton-proton collisions at LHC and can be detected by CMS detector. We used the data which is produced from proton-proton collisions by Monte Carlo events generator for different energies at LHC, then we use the angular distribution, invariant mass, combined transverse momentum and combined rapidity distributions for the two high energy electrons produced from decay channel to detect thesignal. B-L extension of the SM model predicts the existence of aheavy neutral massive boson at high energies. From our results which we had simulated using MC programs forin the B-L extension of standard model, we predict a possible existence of new gaugeat LHC in the mass range 1 TeV to 1.5 TeV via electrons identification of the two high energy electrons by CMS detector.

Assessment of surface hardening effects from shot peening on a Ni-based alloy using electron backscatter diffraction techniques

An electron backscatter diffraction (EBSD)-based tool is described to assess the depth of strain-hardening effects of shot-peening treatments applied to the Ni-based superalloy, Udimet© alloy 720Li. The method consists of a statistical analysis of a number of data points from each grain scanned based on the grain orientation spread and their relative position from the shot-peened edge. The output is a quantitative measure of the depth of strain-hardening effects. The tool is used at various shot-peening intensities to demonstrate the ability to distinguish between these changes, using a range of intensities from 4 to 10 Almen. An increase in shot-peening intensity is observed to increase the depth of strain-hardening effects in the alloy. A comparison with residual stress measurements using X-ray diffraction for the same material shows that the strain-hardened depth determined by EBSD extends to approximately half the distance of the residual stress present due to shot peening. A comparison is also made with predicted profiles from the Peenstress SM model and subsequent microhardness testing. A positive correlation is observed between strained hardened depth and surface roughness of the peened samples. In each case, the increases in surface roughness and strain-hardened depth diminish toward the upper end of the shot-peening intensity range studied for this alloy.

Exploring effects of strong interactions in enhancing masses of dynamical origin

A previous study of the dynamical generation of masses in massless QCD is considered from another viewpoint. The quark mass is assumed to have a dynamical origin and is substituted by a scalar field without self-interaction. The potential for the new field background is evaluated up to two loops. Expressing the running coupling in terms of the scale parameter $\mu$, the potential minimum is chosen to fix $m_{top}=175$ $GeV$ when $\mu_0=498 $ $MeV$. The second derivative of the potential predicts a scalar field mass of 126.76 $GeV$. This number is close to the value 114 $GeV$ which, preliminary data taken at CERN, suggested to be associated with the Higgs particle. However, the simplifying assumptions limit the validity of the calculations done, as indicated by the large value of $\alpha=\frac {g^2}{4\pi}=1.077 $ obtained. However, supporting statements about the possibility of improving the scheme come from the necessary inclusion of weak and scalar field couplings and mass counterterms in the renormalization procedure, in common with the seemingly needed consideration of the massive W and Z fields, if the real conditions of the SM model are intended to be approached.

Optimization of TiO2 concentration effect for a chemical humidity sensing mechanism

PurposeThe purpose of this paper is to propose a new approach to optimize the TiO2 concentration on a resistive‐type humidity sensing mechanism (RHSM) based on artificial neural network.Design/methodology/approachFirst is the modeling of the sensing mechanism. Using neuronal networks and Matlab environment to accurately express the output of the sensing mechanism, this model thus takes into account the parameter, non‐linearity, hysteresis, temperature and frequency; furthermore, the TiO2 concentration effect on the humidity sensing properties in the model is investigated. In a second step, the Matlab environment is used to create a database for an ideal model for the sensing mechanism, where the response of this ideal model is linear for any above parameters value.FindingsAn analytical model for the sensing mechanism “SM” and the ideal model “IM” has been created. The bias matrix and the weights matrix were used to establish the SM model and the IM on performance simulation program with integrated circuit emphasis simulator, where the output of the first is identical to the RHSM output and the output of the last is the ideal response.Originality/valueThe paper proposes an electrical circuit used to optimize the TiO2 concentration of a resistive humidity sensing mechanism.

RENORMALIZATION INVARIANTS AND QUARK FLAVOR MIXINGS

A set of renormalization invariants is constructed using approximate, two-flavor, analytic solutions to RGE's. These invariants exhibit explicitly the correlation between quark flavor mixings and mass ratios from electroweak scale to GUT scale in the context of the SM, DHM and MSSM models. The well-known empirical relations θ23 ∝ ms/mb, θ13 ∝ md/mb at electroweak scale can thus be understood as the result of renormalization evolution toward the infrared point. The validity of this approximation is evaluated by comparing the numerical solutions with the analytical approach. It is found that the scale dependence of these quantities for general three-flavor mixing follows closely these invariants up to the GUT scale.

Performance Prediction and Design Method for Centrifugal Pump Based on Computational Fluid Dynamics

Using Reynolds average N-S equations closed by standard k- turbulence model, the steady and unsteady turbulent flow in centrifugal pump was simulated by using MRF model and SM model respectively. A method for predicting the performances of centrifugal pump was built on the basis of computational fluid dynamics. By the presented performance prediction method, not only the flow characteristics of centrifugal pump can be obtained, but also can its performances be evaluated quantitatively and qualitatively. The advantages and disadvantages of some traditional design methods for centrifugal pump were analyzed. On the basis of performance prediction and flow analysis, a new design method was put forward in consideration of the steady and unsteady performances of centrifugal pump. The proposed method can be used to design the centrifugal pump with high running stability, efficiency and cavitation resistance, and it is available for shortening development period and improving design quality of pump.

Symmetry, dark matter, and LHC phenomenology of the minimalνSM

A sterile neutrino with a mass of a few keV can play the role of a warm dark matter(DM). This can be realized in seesaw models with 3 left- and 3 right-handed neutrinos. It is possible to identify the keV neutrino to be one of the right-handed neutrinos leaving the other two to be much more heavier, the $\nu$SM model. We show that with this realization of keV neutrino DM, the model has an approximate Friedberg-Lee symmetry providing a natural explanation for the lightness of the right-handed neutrino. We also find that in this model the mixing parameters couple light and heavy neutrinos are strongly correlated, and can be large enough to have testable effects at the LHC for the two heavy right-handed neutrinos to be in the hundred-GeV range.

Implications of the measurements ofBs–B¯smixing on supersymmetric models

We derive constraints on the mass insertion parameters from the recent measurements of ${B}_{s}--{\overline{B}}_{s}$ mixing, and discuss their implications on SUSY breaking mediation mechanisms and SUSY flavor models. Some SUSY flavor models are already excluded or disfavored by ${B}_{s}--{\overline{B}}_{s}$ mixing. We also discuss how to test the SM and SUSY models in the future experiments, by studying other $CP$ violating observables related to $b\ensuremath{\rightarrow}s$ transition, such as the time-dependent $CP$ asymmetry in ${B}_{d}\ensuremath{\rightarrow}\ensuremath{\phi}{K}_{S}$ and the direct $CP$ asymmetry in $B\ensuremath{\rightarrow}{X}_{s}\ensuremath{\gamma}$.