THE LIGHT SCALAR BOTTOM QUARK AND c→uγ DECAY

2000 ◽  
Vol 15 (38n39) ◽  
pp. 2345-2357 ◽  
Author(s):  
M. BOZ ◽  
Z. KIRCA
Keyword(s):  
Decay Rate ◽  
W Boson ◽  
Bottom Quark ◽  
Mass Matrices ◽  
Charged Higgs ◽  
Two Generations ◽  
Light Scalar ◽  
Near Future

In this work, we analyze c→uγ decay in supersymmetry for a light sbottom with heavy scalar fermions of the first two generations. Assuming that all generation changing entries of the sfermion mass matrices vanish and, thus considering only chargino, charged Higgs and W-boson contributions only, we calculate the Wilson coefficients and the decay rate at μ=mc level. It is found that, for low tan β regime the decay rate is enhanced up to 5% with respect to the SM. The results presented here are expected to be checked in the CHORUS experiment in the near future.

scholarly journals A cosmic microscope for the preheating era

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
JiJi Fan ◽  
Zhong-Zhi Xianyu
Keyword(s):  
Scalar Field ◽  
Nonlinear Effect ◽  
Large Scale ◽  
Nonlinear Effects ◽  
Light Fields ◽  
Unique Probe ◽  
Light Scalar ◽  
Spatially Varying ◽  
Near Future ◽  
Scalar Perturbations

Abstract Light fields with spatially varying backgrounds can modulate cosmic preheating, and imprint the nonlinear effects of preheating dynamics at tiny scales on large scale fluctuations. This provides us a unique probe into the preheating era which we dub the “cosmic microscope”. We identify a distinctive effect of preheating on scalar perturbations that turns the Gaussian primordial fluctuations of a light scalar field into square waves, like a diode. The effect manifests itself as local non-Gaussianity. We present a model, “modulated partial preheating”, where this nonlinear effect is consistent with current observations and can be reached by near future cosmic probes.

scholarly journals Search for a W′ boson decaying to a vector-like quark and a top or bottom quark in the all-jets final state

2019 ◽  
Vol 2019 (3) ◽  
Author(s):  
A. M. Sirunyan ◽  
◽  
A. Tumasyan ◽  
W. Adam ◽  
F. Ambrogi ◽  
...  
Keyword(s):  
W Boson ◽  
Bottom Quark ◽  
Final State

scholarly journals LIGHT SCALAR DECAY IN A DIQUARK CHIRAL EFFECTIVE THEORY

2012 ◽  
Vol 27 (10) ◽  
pp. 1250051 ◽  
Author(s):  
DEOG KI HONG ◽  
CHAEJUN SONG
Keyword(s):  
Experimental Data ◽  
Decay Rate ◽  
Bound States ◽  
Effective Theory ◽  
Scalar Mesons ◽  
Light Scalar ◽  
Exotic Hadrons ◽  
Good Agreement

We calculate the decay rate of light scalar mesons, using a diquark chiral effective theory, recently proposed to describe exotic hadrons. In the effective theory the light scalar mesons are postulated to be bound states of diquark and antidiquark. We find our results are in good agreement with experimental data. The axial couplings of diquarks with pions and kaons are found to be quite small and the perturbation is reliable. It shows that the diquark picture captures the correct physics of light scalar mesons.

scholarly journals Implications of δlCP~270° and θ23≳45∘ for Texture Specific Lepton Mass Matrices and 0νββ Decay

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Rohit Verma
Keyword(s):  
Neutrino Mass ◽  
Natural Structure ◽  
Mass Matrices ◽  
Neutrino Experiments ◽  
Near Future

We study the phenomenological consequences of recent results from atmospheric and accelerator neutrino experiments, favoring normal neutrino mass ordering m1<m2<m3, a near maximal lepton Dirac CP phase δl~270∘ along with θ23≳45∘, for possible realization of natural structure in the lepton mass matrices characterized by (Mij)~O(mimj) for i,j=1,2,3. It is observed that deviations from parallel texture structures for Ml and Mν are essential for realizing such structures. In particular, such hierarchical neutrino mass matrices are not supportive for a vanishing neutrino mass mν1→0 characterized by Det Mν≠0 and predict mν1≃(0.1–8.0) meV, mν2≃(8.0–13.0) meV, mν3≃(47.0–52.0) meV, Σ≃(56.0–71.0) meV, and 〈mee〉≃(0.01–10.0) meV, respectively, indicating that the task of observing a 0νββ decay may be rather challenging for near future experiments.

Lyapunov-Based Boundary Control of Strain Gradient Microscale Beams With Exponential Decay Rate

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Ramin Vatankhah ◽  
Ali Najafi ◽  
Hassan Salarieh ◽  
Aria Alasty
Keyword(s):  
Decay Rate ◽  
Boundary Control ◽  
Exponential Decay ◽  
Strain Gradient ◽  
Beam Element ◽  
Strain Gradient Theory ◽  
Gradient Theory ◽  
Exponential Decay Rate ◽  
Mass Matrices ◽  
Euler Bernoulli Beam

In nonclassical microbeams, the governing partial differential equation (PDE) of the system and corresponding boundary conditions are obtained based on the nonclassical continuum mechanics. In this study, exponential decay rate of a vibrating nonclassical microscale Euler–Bernoulli beam is investigated using a linear boundary control law and by implementing a proper Lyapunov functional. To illustrate the performance of the designed controllers, the closed-loop PDE model of the system is simulated via finite element method (FEM). To this end, new nonclassical beam element stiffness and mass matrices are developed based on the strain gradient theory and verification of this new beam element is accomplished in this work.

POSITRONIUM PHYSICS BEYOND THE STANDARD MODEL

2002 ◽  
Vol 17 (26) ◽  
pp. 1713-1724 ◽  
Author(s):  
S. N. GNINENKO ◽  
N. V. KRASNIKOV ◽  
A. RUBBIA
Keyword(s):  
Standard Model ◽  
Decay Rate ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Additional Dimension ◽  
Upper Limit ◽  
The Standard Model ◽  
Invisible Decays ◽  
Near Future ◽  
Invisible Decay

Possible manifestations of new physics in rare (exotic) decays of orthopositronium (o - Ps) are briefly reviewed. It is pointed out that models with infinite additional dimension(s) of Randall–Sundrum type predict disappearance of orthopositronium into additional dimension(s). The experimental signature of this effect is the invisible decay of orthopositronium. We point out that this process may occur at a rate within two or three orders of magnitude of the present experimental upper limit. We also propose a model with a light weakly interacting boson leading to o - Ps → invisible decays at the experimentally interesting rate. We discuss this in details and stress that the existence of invisible decay of orthopositronium in vacuum could explain the o - Ps decay rate puzzle. Thus, our result enhances the existing motivation and justifies efforts for a more sensitive search for o - Ps → invisible decay in a near future experiment.

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