scholarly journals B-B \bar mixing parameter using CPP\nu model

2012 ◽  
Author(s):  
Arpitkumar Parmar
Keyword(s):  
Mixing Parameter

scholarly journals Direct detection of atomic dark matter in white dwarfs

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
David Curtin ◽  
Jack Setford
Keyword(s):  
Dark Matter ◽  
Energy Loss ◽  
Cooling Rate ◽  
White Dwarf ◽  
White Dwarfs ◽  
Luminosity Function ◽  
Direct Detection ◽  
Matter Density ◽  
Mixing Parameter ◽  
First Time

Abstract Dark matter could have a dissipative asymmetric subcomponent in the form of atomic dark matter (aDM). This arises in many scenarios of dark complexity, and is a prediction of neutral naturalness, such as the Mirror Twin Higgs model. We show for the first time how White Dwarf cooling provides strong bounds on aDM. In the presence of a small kinetic mixing between the dark and SM photon, stars are expected to accumulate atomic dark matter in their cores, which then radiates away energy in the form of dark photons. In the case of white dwarfs, this energy loss can have a detectable impact on their cooling rate. We use measurements of the white dwarf luminosity function to tightly constrain the kinetic mixing parameter between the dark and visible photons, for DM masses in the range 10−5–105 GeV, down to values of ϵ ∼ 10−12. Using this method we can constrain scenarios in which aDM constitutes fractions as small as 10−3 of the total dark matter density. Our methods are highly complementary to other methods of probing aDM, especially in scenarios where the aDM is arranged in a dark disk, which can make direct detection extremely difficult but actually slightly enhances our cooling constraints.

Kaon physics at the CERN-SPS

2015 ◽  
Vol 39 ◽  
pp. 1560100
Author(s):  
Mario Vormstein
Keyword(s):  
Kaon Physics ◽  
Current Status ◽  
Photon Mass ◽  
Kaon Decay ◽  
Kaon Decays ◽  
Preliminary Results ◽  
Dark Photon ◽  
Mixing Parameter ◽  
Upper Limits ◽  
Photon Signal

The NA48/2 and NA62 collaborations report on recent results, current status, and prospects of kaon physics at the CERN-SPS. The NA62 collaborations aims to measure the decay [Formula: see text] with an uncertainty of 10% or better. The NA62 detector and preliminary results from a pilot run in 2014 are presented. In addition, recent results of the NA48/2 collaboration are reported. A search for Dark Photons has been performed in [Formula: see text] decays via the kaon decays [Formula: see text] and [Formula: see text]. No dark photon signal was observed and new upper limits on the mixing parameter [Formula: see text] and the dark photon mass were computed. We also report the first observation of the kaon decay [Formula: see text].

A simulation study of nonideal mixing effect on the dynamic response of an exothermic CSTR with Cholette’s model

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Chane-Yuan Yang ◽  
Yu-Shu Chien ◽  
Jun-Hong Chou
Keyword(s):  
Transfer Function ◽  
Dynamic Response ◽  
The Other ◽  
System Stability ◽  
Mixing Effect ◽  
Characteristic Roots ◽  
Mixing Parameter ◽  
Perfect Mixing ◽  
And Control ◽  
Inverse Response

Abstract The study of nonideal mixing effect on the dynamic behaviors of CSTRs has very rarely been published in the literature. In this work, Cholette’s model is employed to explore the nonideal mixing effect on the dynamic response of a nonisothermal CSTR. The analysis shows that the mixing parameter n (the fraction of the feed entering the zone of perfect mixing) and m (the fraction of the total volume of the reactor), indeed affect the characteristic roots of transfer function of a real CSTR, which determine the system stability. On the other hand, the inverse response and overshoot response are also affected by the nonideal mixing in a nonisothemal CSTR. These results are of much help for the design and control of a real CSTR.

A Novel Parameter for the Evaluation of Static Mixers

2018 ◽  
Author(s):  
Morgan Thomas ◽  
Thomas Eldredge ◽  
Hector Medina ◽  
David Fazzina
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Operating Time ◽  
Entropy Change ◽  
Time Cost ◽  
Transfer Rates ◽  
Static Mixers ◽  
Mixing Parameter ◽  
Potential Applications ◽  
Computational Fluid Dynamics Cfd

Static, or motionless, mixers are widely used in applications that involve chemical reactions, heat transfer, blending of fluids, or a combination of these. Within those applications, mixing can affect various parameters such as heat or mass transfer rates, process operating time, cost, safety, and product quality. Therefore, it is crucial to assess the performance of static mixers. In general, their performance is evaluated based on their ability to carry out mixing while minimizing energy loss. To accomplish this, a novel mixing parameter, the M number, is proposed and evaluated. The M number is a unitless parameter that describes the effects of the mixer using entropy change and pressure drop. The parameter is compared to another method of mixing evaluation that relies on Covariance (CoV) change across the mixer. Computational Fluid Dynamics (CFD) is executed using both methods to evaluate two static mixers and compare the results of each method. Potential applications for the M number are discussed and its limitations are noted.

scholarly journals Extreme Value Analysis for Mixture Models with Heavy-Tailed Impurity

Mathematics ◽  
2021 ◽  
Vol 9 (18) ◽  
pp. 2208
Author(s):  
Ekaterina Morozova ◽  
Vladimir Panov
Keyword(s):  
Stock Returns ◽  
Mixture Models ◽  
Extreme Value ◽  
Extreme Value Analysis ◽  
Value Analysis ◽  
Numerical Examples ◽  
Proposed Model ◽  
Mixing Parameter ◽  
Heavy Tailed ◽  
Regularly Varying Distribution

This paper deals with the extreme value analysis for the triangular arrays which appear when some parameters of the mixture model vary as the number of observations grows. When the mixing parameter is small, it is natural to associate one of the components with “an impurity” (in the case of regularly varying distribution, “heavy-tailed impurity”), which “pollutes” another component. We show that the set of possible limit distributions is much more diverse than in the classical Fisher–Tippett–Gnedenko theorem, and provide the numerical examples showing the efficiency of the proposed model for studying the maximal values of the stock returns.

QCD CORRECTION FACTORS FOR $K^0 -\overline K^0$ MIXING FOR LARGE TOP QUARK MASS

1990 ◽  
Vol 05 (11) ◽  
pp. 877-885 ◽  
Author(s):  
JONATHAN M. FLYNN
Keyword(s):  
Top Quark ◽  
Quark Mass ◽  
Correction Factors ◽  
Top Quark Mass ◽  
Factor B ◽  
Quark Masses ◽  
Effective Lagrangian ◽  
Mixing Parameter ◽  
200 Gev ◽  
Top Mass

I modify the calculation of the QCD correction factors in the ΔS = 2 effective Lagrangian for [Formula: see text] mixing to allow top quark masses in the range 50 GeV to 200 GeV. I give constraints on the top mass and Kobayashi-Maskawa phase, determined from the measured [Formula: see text] mixing parameter ε, and find that the factor BK and the ratio |Vub/Vcb| cannot both be smalI if mt < 200 GeV .

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