The density dependence of the Hanle effect in the resonance line of atomic barium

1977 ◽  
Vol 55 (1) ◽  
pp. 83-91 ◽  
Author(s):  
F. M. Kelly ◽  
M. S. Mathur
Keyword(s):  
Cross Sections ◽  
Resonance Line ◽  
Excited Level ◽  
Ground Level ◽  
Multipole Moment ◽  
Low Density ◽  
Density Region ◽  
Hanle Effect ◽  
Wide Range ◽  
Theoretical Predictions

The change in the Hanle effect of the singlet resonance line of neutral barium has been studied over a wide range of density. The low density region has been used to confirm a lifetime of 8.37 ± 0.08 ns for the 6s6p1P1 level. We have determined the cross sections for the relaxation of the multipole moment of order 2 for collisions of the excited level with the ground level and with the metastable 6s5d1D2 level, and comparisons are made with the measured value of [Formula: see text] for the ground level with theoretical predictions.

The density dependence of the Hanle effect in the resonance line of atomic magnesium

1978 ◽  
Vol 56 (11) ◽  
pp. 1422-1425 ◽  
Author(s):  
F. M. Kelly ◽  
M. S. Mathur
Keyword(s):  
Density Dependence ◽  
Cross Section ◽  
Resonance Line ◽  
Neutral Atom ◽  
Ground Level ◽  
Hanle Effect ◽  
Wide Range

The Hanle width and hence the lifetime of the first excited 1P1 level of neutral magnesium have been measured over a wide range of densities. The natural lifetime of the 3s3p1P1 level is 2.00 ns. The depolarization cross section for collisions with the ground level neutral atom has been measured and [Formula: see text].

Density dependence of the Hanle effect of the 4s4p1P1 level of neutral calcium

1980 ◽  
Vol 58 (7) ◽  
pp. 1004-1009 ◽  
Author(s):  
F. M. Kelly ◽  
M. S. Mathur
Keyword(s):  
Density Dependence ◽  
High Density ◽  
Low Density ◽  
Density Region ◽  
Hanle Effect ◽  
Wide Range ◽  
High Density Region

The Hanle effect in the 4s21S0–4s4p1P1 (4226.7 Å) transition in Ca I has been observed over a wide range of densities. The low density observations determine the lifetime of the 1P1 level to be 4.49 ns. Collision parameters are obtained from observations in the high density region.

Hanle effect in the singlet excited states of the alkaline earths

1980 ◽  
Vol 58 (10) ◽  
pp. 1416-1419 ◽  
Author(s):  
F. M. Kelly ◽  
M. S. Mathur
Keyword(s):  
Excited States ◽  
Cross Sections ◽  
Ground Level ◽  
High Density ◽  
Oscillator Strengths ◽  
Low Density ◽  
Density Data ◽  
Hanle Effect ◽  
Singlet States ◽  
Alkaline Earths

The Hanle effect in the singlet states of Sr, Ba, Mg, and Ca has been studied over a range of densities. The low density observations lead to an accurate lifetime measurement of the singlet excited levels, and calculation of the related oscillator strengths. The depolarization cross sections, [Formula: see text], for collision with ground level neutral atoms have been obtained from the high density data.

Density dependence of the Hanle effect of the 3s4p1P10 level of neutral magnesium

1979 ◽  
Vol 57 (6) ◽  
pp. 838-840
Author(s):  
F. M. Kelly ◽  
M. S. Mathur
Keyword(s):  
Density Dependence ◽  
Excited Level ◽  
Lifetime Measurement ◽  
Oscillator Strengths ◽  
Low Density ◽  
Hanle Effect

The Hanle effect in the 3s2 1S0–3s4p1P1 (2026 Å) transition of Mg I has been studied over a range of densities. The low density observations lead to an accurate lifetime measurement of the 4p1P1 excited level. Related oscillator strengths are calculated.

Monte Carlo and Perturbation Calculations for a Triangular Well Fluid

1974 ◽  
Vol 52 (1) ◽  
pp. 80-88 ◽  
Author(s):  
Damon N. Card ◽  
John Walkley
Keyword(s):  
Monte Carlo ◽  
Hard Spheres ◽  
Low Density ◽  
Monte Carlo Data ◽  
Density Region ◽  
Wide Range ◽  
Model Fluid ◽  
High Density Region ◽  
Superposition Approximation ◽  
Triangular Well Potential

Monte Carlo data have been generated for a simple model fluid consisting of hard spheres with an attractive triangular well potential. The ranges spanned by the temperature and density are as follows. [Formula: see text] and [Formula: see text]. The machine data have been compared to the modern perturbation theories of (i) Barker, Henderson, and Smith and (ii) Weeks, Chandler, and Andersen. Comparison with the machine data shows that the latter theory is successful in the high density region only, but over a wide range of temperature. The Barker–Henderson approach is best in the low density region but the use of the superposition approximation limits the utility of this theory at high densities.

Hanle effect of the level of calcium and its density dependence

1982 ◽  
Vol 60 (9) ◽  
pp. 1237-1240 ◽  
Author(s):  
M. S. Mathur ◽  
F. M. Kelly
Keyword(s):  
Density Dependence ◽  
Cross Section ◽  
Ground Level ◽  
Neutral Atoms ◽  
Hanle Effect ◽  
Wide Range

The Hanle width and hence the lifetime of the [Formula: see text] level of neutral calcium has been measured over a wide range of densities. The natural lifetime of the [Formula: see text] level is 20.07 ns. The depolarization cross section for collision with the ground level neutral atoms has been measured and [Formula: see text].

scholarly journals Dependence of the structural parameters and properties of low density polyethylene on the synthesis conditions

1999 ◽  
Vol 64 (10) ◽  
pp. 577-587
Author(s):  
Dragoslav Stoiljkovic ◽  
Radmila Radicevic ◽  
Milovan Jankovic
Keyword(s):  
Experimental Data ◽  
Structural Parameters ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Structure And Properties ◽  
Synthesis Conditions ◽  
Wide Range ◽  
Theoretical Predictions ◽  
Mathematical Relationships ◽  
Polymerization Conditions

In a previous publicaitons from the authors.laboratotry a method was developed to predict the structure and properties of low density polyethylene (PE-LD) that could be obtained over a very wide range of polymerization conditions. The method was proved using experimental data from the literature. However, some shortcomings of the method were noticed. The aim of this work was to overcome the shortcomings and to enable the better manipulation of experimental data using a computer. A computer program has been developed to establish the mathematical relationships between ethylene entropy and the structural parameters and density of Pe-LD. All available experimental data (more than 300 experimental points) have elaborated and confirmed our mathematical models and our theoretical predictions.

scholarly journals Measurements of event properties and multi-differential jet cross sections and impact of CMS measurements on Proton Structure and QCD parameters

2018 ◽  
Vol 172 ◽  
pp. 02001
Author(s):  
Anterpreet Kaur
Keyword(s):  
Cross Sections ◽  
Top Quark ◽  
Center Of Mass ◽  
Distribution Functions ◽  
Parton Distribution Functions ◽  
Mass Distributions ◽  
Inclusive Jets ◽  
Wide Range ◽  
Theoretical Predictions ◽  
Jet Cross Sections

We present results on the measurements of characteristics of events with jets including jet-charge, investigations of shapes and jet mass distributions. The measurements are compared to theoretical predictions including those matched to parton shower and hadronization. Multi-differential jet cross sections are also presented over a wide range in transverse momenta from inclusive jets to multi-jet final states. These measurements have an impact on the determination of the strong coupling constant as well as on parton distribution functions (PDFs) and are helpful in the treatment of heavy flavours in QCD analyses. We also show angular correlations in multi-jet events at highest center-of-mass energies and compare the measurements to theoretical predictions including higher order parton radiation and coherence effects. Measurements of cross sections of jet and top-quark pair production are in particular sensitive to the gluon distribution in the proton, while the electroweak boson production - inclusive or associated with charm or beauty quarks - gives insight into the flavour separation of the proton sea and to the treatment of heavy quarks in PDF-related studies.

QCD at Fixed Order: Processes

2018 ◽  
Author(s):  
John Campbell ◽  
Joey Huston ◽  
Frank Krauss
Keyword(s):  
Hadron Collider ◽  
Detailed Comparison ◽  
Theoretical Description ◽  
Higgs Bosons ◽  
Final States ◽  
Collider Physics ◽  
Wide Range ◽  
Theoretical Predictions ◽  
Fixed Order ◽  
The Subject

At the core of any theoretical description of hadron collider physics is a fixed-order perturbative treatment of a hard scattering process. This chapter is devoted to a survey of fixed-order predictions for a wide range of Standard Model processes. These range from high cross-section processes such as jet production to much more elusive reactions, such as the production of Higgs bosons. Process by process, these sections illustrate how the techniques developed in Chapter 3 are applied to more complex final states and provide a summary of the fixed-order state-of-the-art. In each case, key theoretical predictions and ideas are identified that will be the subject of a detailed comparison with data in Chapters 8 and 9.

scholarly journals Vector boson fusion at multi-TeV muon colliders

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Antonio Costantini ◽  
Federico De Lillo ◽  
Fabio Maltoni ◽  
Luca Mantani ◽  
Olivier Mattelaer ◽  
...  
Keyword(s):  
Cross Sections ◽  
Vector Boson ◽  
High Energy ◽  
New Physics ◽  
Vector Boson Fusion ◽  
Weak Boson ◽  
Wide Range ◽  
Lepton Colliders ◽  
Muon Colliders ◽  
New Phenomena

Abstract High-energy lepton colliders with a centre-of-mass energy in the multi-TeV range are currently considered among the most challenging and far-reaching future accelerator projects. Studies performed so far have mostly focused on the reach for new phenomena in lepton-antilepton annihilation channels. In this work we observe that starting from collider energies of a few TeV, electroweak (EW) vector boson fusion/scattering (VBF) at lepton colliders becomes the dominant production mode for all Standard Model processes relevant to studying the EW sector. In many cases we find that this also holds for new physics. We quantify the size and the growth of VBF cross sections with collider energy for a number of SM and new physics processes. By considering luminosity scenarios achievable at a muon collider, we conclude that such a machine would effectively be a “high-luminosity weak boson collider,” and subsequently offer a wide range of opportunities to precisely measure EW and Higgs couplings as well as discover new particles.

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