scholarly journals Field theory approach in kinetic reaction: Role of random sources and sinks

2011 ◽  
Vol 169 (1) ◽  
pp. 1489-1498 ◽  
Author(s):  
M. Hnatich ◽  
J. Honkonen ◽  
T. Lučivjanský
Keyword(s):  
Field Theory ◽  
Theory Approach ◽  
Kinetic Reaction ◽  
Sources And Sinks

scholarly journals THE ROLE OF THE Δ(1232)-RESONANCE IN COVARIANT BARYON CHIRAL PERTURBATION THEORY

2014 ◽  
Vol 26 ◽  
pp. 1460088
Author(s):  
J. M. ALARCÓN
Keyword(s):  
Field Theory ◽  
Perturbation Theory ◽  
Effective Field Theory ◽  
Effective Field ◽  
Scattering Data ◽  
Theory Approach ◽  
Chiral Perturbation ◽  
Chiral Effective Field Theory ◽  
Dynamical Degree

We stress, on theoretical and phenomenological grounds, the importance of the Δ(1232)-resonance in a chiral effective field theory approach to the study of πN scattering. We show how its inclusion as a dynamical degree of freedom allow us to obtain reliably valuable information from πN scattering data.

scholarly journals Spin effects in the effective field theory approach to Post-Minkowskian conservative dynamics

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Zhengwen Liu ◽  
Rafael A. Porto ◽  
Zixin Yang
Keyword(s):  
Field Theory ◽  
Effective Field Theory ◽  
Scattering Problem ◽  
Finite Size ◽  
Effective Field ◽  
Compact Objects ◽  
Scattering Data ◽  
Theory Approach ◽  
Spin Effects ◽  
Radial Action

Abstract Building upon the worldline effective field theory (EFT) formalism for spinning bodies developed for the Post-Newtonian regime, we generalize the EFT approach to Post-Minkowskian (PM) dynamics to include rotational degrees of freedom in a manifestly covariant framework. We introduce a systematic procedure to compute the total change in momentum and spin in the gravitational scattering of compact objects. For the special case of spins aligned with the orbital angular momentum, we show how to construct the radial action for elliptic-like orbits using the Boundary-to-Bound correspondence. As a paradigmatic example, we solve the scattering problem to next-to-leading PM order with linear and bilinear spin effects and arbitrary initial conditions, incorporating for the first time finite-size corrections. We obtain the aligned-spin radial action from the resulting scattering data, and derive the periastron advance and binding energy for circular orbits. We also provide the (square of the) center-of-mass momentum to $$ \mathcal{O}\left({G}^2\right) $$ O G 2 , which may be used to reconstruct a Hamiltonian. Our results are in perfect agreement with the existent literature, while at the same time extend the knowledge of the PM dynamics of compact binaries at quadratic order in spins.

scholarly journals Decision Making from the Experience of Orthognathic Surgery Patients: A Grounded Theory Approach

2021 ◽  
pp. 238008442110144
Author(s):  
N.R. Paul ◽  
S.R. Baker ◽  
B.J. Gibson
Keyword(s):  
Decision Making ◽  
Grounded Theory ◽  
Treatment Options ◽  
Study Data ◽  
Primary Objective ◽  
Major Surgery ◽  
Future Research ◽  
Decision Making Process ◽  
Theory Approach

Introduction: Patients’ decisions to undergo major surgery such as orthognathic treatment are not just about how the decision is made but what influences the decision. Objectives: The primary objective of the study was to identify the key processes involved in patients’ experience of decision making for orthognathic treatment. Methods: This study reports some of the findings of a larger grounded theory study. Data were collected through face-to-face interviews of patients who were seen for orthognathic treatment at a teaching hospital in the United Kingdom. Twenty-two participants were recruited (age range 18–66 y), of whom 12 (male = 2, female = 10) were 6 to 8 wk postsurgery, 6 (male = 2, female = 4) were in the decision-making stage, and 4 (male = 0, female = 4) were 1 to 2 y postsurgery. Additional data were also collected from online blogs and forums on jaw surgery. The data analysis stages of grounded theory methodology were undertaken, including open and selective coding. Results: The study identified the central role of dental care professionals (DCPs) in several underlying processes associated with decision making, including legitimating, mediating, scheduling, projecting, and supporting patients’ decisions. Six categories were related to key aspects of decision making. These were awareness about their underlying dentofacial problems and treatment options available, the information available about the treatment, the temporality of when surgery would be undertaken, the motivations and expectation of patients, social support, and fear of the surgery, hospitalization, and potentially disliking their new face. Conclusion: The decision-making process for orthognathic treatment is complex, multifactorial, and heavily influenced by the role of DCPs in patient care. Understanding the magnitude of this role will enable DCPs to more clearly participate in improving patients’ decision-making process. The findings of this study can inform future quantitative studies. Knowledge Transfer Statement: The results of this study can be used both for informing clinical practice around enabling decision making for orthognathic treatment and also for designing future research. The findings can better inform clinicians about the importance of their role in the patients’ decision-making process for orthognathic treatment and the means to improve the patient experience. It is suggested that further research could be conducted to measure some of the key constructs identified within our grounded theory and assess how these change during the treatment process.

scholarly journals Precision Higgs couplings in neutral naturalness models: an effective field theory approach

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Lucien Heurtier ◽  
Hao-Lin Li ◽  
Huayang Song ◽  
Shufang Su ◽  
Wei Su ◽  
...  
Keyword(s):  
Field Theory ◽  
Effective Field Theory ◽  
Goldstone Boson ◽  
Higgs Sector ◽  
New Physics ◽  
Effective Field ◽  
Precision Measurements ◽  
Global Symmetry ◽  
Theory Approach ◽  
Decay Channels

AbstractThe Higgs sector in neutral naturalness models provides a portal to the hidden sectors, and thus measurements of Higgs couplings at current and future colliders play a central role in constraining the parameter space of the model. We investigate a class of neutral naturalness models, in which the Higgs boson is a pseudo-Goldstone boson from the universal SO(N)/SO(N −1) coset structure. Integrating out the radial mode from the spontaneous global symmetry breaking, we obtain various dimension-six operators in the Standard Model effective field theory, and calculate the low energy Higgs effective potential with radiative corrections included. We perform aχ2fit to the Higgs coupling precision measurements at current and future colliders and show that the new physics scale could be explored up to 2.3 (2.4) TeV without (with) the Higgs invisible decay channels at future Higgs factories. The limits are comparable to the indirect constraints obtained via electroweak precision measurements.

scholarly journals Celestial superamplitude in $$ \mathcal{N} $$ = 4 SYM theory

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Hongliang Jiang
Keyword(s):  
Field Theory ◽  
Conformal Field Theory ◽  
Scattering Amplitudes ◽  
Momentum Space ◽  
Ward Identity ◽  
Yang Mills ◽  
Conformal Field ◽  
New Perspective ◽  
Celestial Sphere

Abstract Celestial amplitude is a new reformulation of momentum space scattering amplitudes and offers a promising way for flat holography. In this paper, we study the celestial amplitudes in $$ \mathcal{N} $$ N = 4 Super-Yang-Mills (SYM) theory aiming at understanding the role of superconformal symmetry in celestial holography. We first construct the superconformal generators acting on the celestial superfield which assembles all the on-shell fields in the multiplet together in terms of celestial variables and Grassmann parameters. These generators satisfy the superconformal algebra of $$ \mathcal{N} $$ N = 4 SYM theory. We also compute the three-point and four-point celestial super-amplitudes explicitly. They can be identified as the conformal correlation functions of the celestial superfields living at the celestial sphere. We further study the soft and collinear limits which give rise to the super-Ward identity and super-OPE on the celestial sphere, respectively. Our results initiate a new perspective of understanding the well-studied $$ \mathcal{N} $$ N = 4 SYM amplitudes via 2D celestial conformal field theory.

Quantifying sources and sinks of trace gases using space-borne measurements: current and future science

2008 ◽  
Vol 366 (1885) ◽  
pp. 4509-4528 ◽  
Author(s):  
Paul I Palmer
Keyword(s):  
Trace Gases ◽  
Lower Troposphere ◽  
Biological Interactions ◽  
Satellite Measurements ◽  
Sources And Sinks ◽  
The Past ◽  
Fundamental Understanding ◽  
Earth’S Climate ◽  
New Generation

We have been observing the Earth's upper atmosphere from space for several decades, but only over the past decade has the necessary technology begun to match our desire to observe surface air pollutants and climate-relevant trace gases in the lower troposphere, where we live and breathe. A new generation of Earth-observing satellites, capable of probing the lower troposphere, are already orbiting hundreds of kilometres above the Earth's surface with several more ready for launch or in the planning stages. Consequently, this is one of the most exciting times for the Earth system scientists who study the countless current-day physical, chemical and biological interactions between the Earth's land, ocean and atmosphere. First, I briefly review the theory behind measuring the atmosphere from space, and how these data can be used to infer surface sources and sinks of trace gases. I then present some of the science highlights associated with these data and how they can be used to improve fundamental understanding of the Earth's climate system. I conclude the paper by discussing the future role of satellite measurements of tropospheric trace gases in mitigating surface air pollution and carbon trading.

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