Cross Sections, Decay Widths, and Lifetimes; W and Z Decays

2018 ◽  
pp. 77-87
Keyword(s):  
Cross Sections ◽  
Z Decays ◽  
Decay Widths

scholarly journals Factorization in the model of unstable particles with continuous masses

Open Physics ◽  
2013 ◽  
Vol 11 (2) ◽  
Author(s):  
Vladimir Kuksa ◽  
Nikolay Volchanskiy
Keyword(s):  
Cross Sections ◽  
Factorization Method ◽  
Phenomenological Analysis ◽  
Specific Structure ◽  
Interacting Particles ◽  
Unstable Particles ◽  
Decay Widths ◽  
Intermediate Time ◽  
Exact Factorization

AbstractWe study processes with unstable particles in intermediate time-like states. It is shown that the amplitudes squared of such processes factor exactly in the framework of the model of unstable particles with continuous masses. Decay widths and cross sections can then be represented in a universal factorized form for an arbitrary set of interacting particles. This exact factorization is caused by specific structure of propagators in the model. We formulate the factorization method and perform a phenomenological analysis of the factorization effects. The factorization method considerably simplifies calculations while leading to compact and reasonable results.

scholarly journals Excited Muon Searches at the FCC-Based Muon-Hadron Colliders

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
A. Caliskan ◽  
S. O. Kara ◽  
A. Ozansoy
Keyword(s):  
Transverse Momentum ◽  
Cross Sections ◽  
Production Cross ◽  
Muon Decay ◽  
Hadron Colliders ◽  
Final State ◽  
Decay Widths ◽  
Muon Production ◽  
Pseudorapidity Distributions ◽  
Excited Muons

We study the excited muon production at the FCC-based muon-hadron colliders. We give the excited muon decay widths and production cross-sections. We deal with the μp→μ⋆q→μγq process and plot the transverse momentum and normalized pseudorapidity distributions of final state particles to define the kinematical cuts best suited for discovery. By using these cuts, we get the mass limits for excited muons. It is shown that the discovery limits obtained on the mass of μ⋆ are 2.2, 5.8, and 7.5 TeV for muon energies of 63, 750, and 1500 GeV, respectively.

scholarly journals Study on the Resonant Parameters of Y (4220) and Y (4390)

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Jielei Zhang ◽  
Limin Yuan ◽  
Rumin Wang
Keyword(s):  
Cross Sections ◽  
Leptonic Decay ◽  
Decay Widths ◽  
The Cross ◽  
Lower Limits

Many vector charmonium-like states have been reported recently in the cross sections of e+e-→ωχc0, π+π-hc, π+π-J/ψ, π+π-ψ(3686), and π+D0D⁎-+c.c. To better understand the nature of these states, a combined fit is performed to these cross sections by using three resonances Y(4220), Y(4390), and Y(4660). The resonant parameters for the three resonances are obtained. We emphasize that two resonances Y(4220) and Y(4390) are sufficient to explain these cross sections below 4.6 GeV. The lower limits of Y(4220) and Y(4390)’s leptonic decay widths are also determined to be (36.4±2.0±4.2) and (123.8±6.5±9.0) eV.

Tools for Calculation

2019 ◽  
pp. 95-110
Author(s):  
Michael E. Peskin
Keyword(s):  
Elementary Particle ◽  
Phase Space ◽  
Cross Sections ◽  
Feynman Diagrams ◽  
Decay Widths ◽  
Relativistic Phase

This chapter discusses the calculation of quantities observable in elementary particle reactions — cross sections and partial decay widths. It introduces relativistic phase space. It introduces Feynman diagrams and describes their role in visualizing elementary particle reactions.

scholarly journals Excited Neutrino Search Potential of the FCC-Based Electron-Hadron Colliders

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
A. Caliskan
Keyword(s):  
Cross Sections ◽  
Production Cross ◽  
Center Of Mass ◽  
Branching Ratios ◽  
Hadron Colliders ◽  
Production Potential ◽  
Decay Channels ◽  
Decay Widths

The production potential of the excited neutrinos at the FCC-based electron-hadron colliders, namely, the ERL60⊗FCC with s=3.46 TeV, the ILC⊗FCC with s=10 TeV, and the PWFA-LC⊗FCC with s=31.6 TeV, has been analyzed. The branching ratios of the excited neutrinos have been calculated for the different decay channels and shown that the dominant channel is ν⋆→eW+. We have calculated the production cross sections with the process of ep→ν⋆q→eW+q and the decay widths of the excited neutrinos with the process of ν⋆→eW+. The signals and corresponding backgrounds are studied in detail to obtain accessible mass limits. It is shown that the discovery limits obtained on the mass of the excited neutrino are 2452 GeV for Lint=100 fb-1, 5635 GeV for Lint=10 fb-1 (6460 GeV for Lint=100 fb-1), and 10200 GeV for Lint=1 fb-1 (13960 GeV for Lint=10 fb-1), for the center-of-mass energies of 3.46, 10, and 31.6 TeV, respectively.

scholarly journals Decay widths and total cross sections in perturbative QCD

1996 ◽  
Vol 68 (1) ◽  
pp. 259-303 ◽  
Author(s):  
Levan R. Surguladze ◽  
Mark A. Samuel
Keyword(s):  
Perturbative Qcd ◽  
Cross Sections ◽  
Total Cross Sections ◽  
Decay Widths

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

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