scholarly journals Potential linear and angular momentum in the scalar diquark model

2021 ◽  
Vol 81 (7) ◽  
Author(s):  
David Arturo Amor-Quiroz ◽  
Matthias Burkardt ◽  
William Focillon ◽  
Cédric Lorcé
Keyword(s):  
Angular Momentum ◽  
Transverse Momentum ◽  
Direct Calculation ◽  
Final State ◽  
Diquark Model ◽  
Scalar Diquark ◽  
Angular Momenta ◽  
The Difference ◽  
Definition Of ◽  
Quark Transverse Momentum

AbstractWe present an analytic two-loop calculation within the scalar diquark model of the potential linear and angular momenta, defined as the difference between the Jaffe-Manohar and Ji notions of linear and angular momenta. As expected by parity and time-reversal symmetries, a direct calculation confirms that the potential transverse momentum coincides with the Jaffe-Manohar (or canonical) definition of average quark transverse momentum, also known as the quark Sivers shift. We examine whether initial/final-state interactions at the origin of the Sivers asymmetry can also generate a potential angular momentum in the scalar diquark model.

scholarly journals Quark Orbital Angular Momentum and Final State Interactions

2015 ◽  
Vol 37 ◽  
pp. 1560035 ◽  
Author(s):  
Matthias Burkardt
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Final State ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Wigner Distributions ◽  
Single Spin Asymmetries ◽  
Quark Orbital Angular Momentum ◽  
The Difference ◽  
Definition Of

Definitions of orbital angular momentum based on Wigner distributions are used to discuss the connection between the Ji definition of the quark orbital angular momentum and that of Jaffe and Manohar. The difference between these two definitions can be interpreted as the change in the quark orbital angular momentum as it leaves the target in a DIS experiment. The mechanism responsible for that change is similar to the mechanism that causes transverse single-spin asymmetries in semi-inclusive deep-inelastic scattering.

scholarly journals QUARK ORBITAL ANGULAR MOMENTUM AND FINAL STATE INTERACTIONS

2014 ◽  
Vol 25 ◽  
pp. 1460029 ◽  
Author(s):  
MATTHIAS BURKARDT
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Final State ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Wigner Distributions ◽  
Single Spin Asymmetries ◽  
Quark Orbital Angular Momentum ◽  
The Difference ◽  
Definition Of

Definitions of orbital angular momentum based on Wigner distributions are used to discuss the connection between the Ji definition of the quark orbital angular momentum and that of Jaffe and Manohar. The difference between these two definitions can be interpreted as the change in the quark orbital angular momentum as it leaves the target in a DIS experiment. The mechanism responsible for that change is similar to the mechanism that causes transverse single-spin asymmetries in semi-inclusive deep-inelastic scattering.

scholarly journals Λ/Λ̄ Longitudinal Spin Transfer from Asymmetric Nucleon s/s̄ Distribution

2016 ◽  
Vol 40 ◽  
pp. 1660026
Author(s):  
Xiaozhen Du ◽  
Yujie Chi ◽  
Bo-Qiang Ma
Keyword(s):  
Experimental Data ◽  
Transverse Momentum ◽  
Light Cone ◽  
Spin Transfer ◽  
Compass Collaboration ◽  
Diquark Model ◽  
Hyperon Decay ◽  
Longitudinal Spin ◽  
Distribution Effect ◽  
The Difference

We investigate quark to [Formula: see text] and [Formula: see text] longitudinal spin transfers in the light-cone SU(6) quark sepctator-diquark model and try to analyze the possible origins for the spin transfer difference between them measured by the COMPASS collaboration. The intermediate heavier hyperon decay processes are considered, while the final hadron transverse momentum is also included. We find that after taking into account the asymmetric nucleon [Formula: see text] distribution effect, the results we get are qualitatively comparable with the difference of the COMPASS experimental data.

GPDs AND TMDs

2012 ◽  
Vol 20 ◽  
pp. 75-83
Author(s):  
MATTHIAS BURKARDT
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Transverse Plane ◽  
Final State ◽  
Parton Distributions ◽  
Generalized Parton Distributions ◽  
Wigner Distributions ◽  
Quark Orbital Angular Momentum ◽  
Final State Interactions ◽  
The Difference

For transversely polarized nucleons the distribution of quarks in the transverse plane is transversely shifted and that shift can be described in terms of Generalized Parton Distributions (GPDs). This observation provides a 'partonic' derivation of the Ji-relation for the quark angular momentum in terms of GPDs. Wigner distributions are used to show that the difference between the Jaffe-Manohar definiton of quark orbital angular momentum and that of Ji is equal to the change of orbital angular momentum due to the final state interactions as the struck quark leaves the target in a DIS experiment.

scholarly journals Jet timing

2022 ◽  
Vol 2022 (1) ◽  
Author(s):  
Wen Han Chiu ◽  
Zhen Liu ◽  
Matthew Low ◽  
Lian-Tao Wang
Keyword(s):  
Transverse Momentum ◽  
Relevant Information ◽  
Weighted Sum ◽  
Final State ◽  
Arrival Times ◽  
Jet Trajectory ◽  
The Times ◽  
Definition Of ◽  
The Time Domain ◽  
Displaced Vertex

Abstract The measurement of the arrival time of a particle, such as a lepton, a photon, or a pion, reaching the detector provides valuable information. A similar measurement for a hadronic final state, however, is much more challenging as one has to extract the relevant information from a collection of particles. In this paper, we explore various possibilities in defining the time of a jet through the measurable arrival times of the jet constituents. We find that a definition of jet time based on a transverse momentum weighted sum of the times of the constituents has the best performance. For prompt jets, the performance depends on the jet trajectory. For delayed jets, the performance depends on the trajectory of the jet, the trajectory of the mother particle, and the location of the displaced vertex. Compared to the next-best-performing jet time definition, the transverse momentum weighted sum has roughly a factor of ten times better jet time resolution. We give a detailed discussion of the relevant effects and characterize the full geometrical dependence of the performance. These results highlight the critical importance of using a proper definition of jet time with its corresponding detector-dependent calibration and the exciting possibility of deepening our understanding of jets in the time domain.

Properties of spin and orbital angular momenta of light

2021 ◽  
Vol 36 (26) ◽  
Author(s):  
Arvind ◽  
S. Chaturvedi ◽  
N. Mukunda
Keyword(s):  
Angular Momentum ◽  
Physical Properties ◽  
Degree Of Freedom ◽  
Polarization Degree ◽  
Quantum Mechanical ◽  
Light Fields ◽  
Spin Part ◽  
Full Account ◽  
Angular Momenta ◽  
Definition Of

This paper analyses the algebraic and physical properties of the spin and orbital angular momenta of light in the quantum mechanical framework. The consequences of the fact that these are not angular momenta in the quantum mechanical sense are worked out in mathematical detail. It turns out that the spin part of the angular momentum has continuous eigenvalues. Particular attention is given to the paraxial limit, and to the definition of Laguerre–Gaussian modes for photons as well as classical light fields taking full account of the polarization degree of freedom.

scholarly journals Orbital Angular Momentum in Scalar Diquark Model and QED

2011 ◽  
Vol 52 (3-4) ◽  
pp. 389-395 ◽  
Author(s):  
Hikmat BC ◽  
Matthias Burkardt
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Diquark Model ◽  
Scalar Diquark

Electron Spin and General Angular Momenta

2020 ◽  
pp. 356-376
Author(s):  
Jochen Autschbach
Keyword(s):  
Angular Momentum ◽  
Electron Spin ◽  
Open Shell ◽  
Historical Background ◽  
Ladder Operators ◽  
Spin Orbital ◽  
Angular Momenta ◽  
Pauli Matrices ◽  
Spin Singlet ◽  
Definition Of

The historical background of the discovery of the electron spin is provided. The Stern-Gerlach and Einstein-de Haas experiments are discussed. The operators for a single electron spin are defined, along with the formulation in terms of the 2x2 Pauli matrices. The discussion then moves on to the definition of the spin for many-electron systems and explains how the famous Hund rule (or Hund’s first rule) arises from considering the energy of an open-shell spin singlet vs. triplet state. Next, the generalized angular momentum, ladder operators, and spherical vector operators are defined, and the rules for the addition of angular momenta are derived. The chapter concludes with a discussion of the total spin, orbital, and total angular momentum for open-shell atoms, term symbols, and Hund’s second and third rule.

scholarly journals The angular momentum decomposition in the scalar diquark model.

2019 ◽  
Author(s):  
Arturo Amor-Quiroz ◽  
Matthias Burkardt ◽  
Cedric Lorce
Keyword(s):  
Angular Momentum ◽  
Diquark Model ◽  
Scalar Diquark

The Distinction between [P] and [S]

2017 ◽  
Author(s):  
Galen Strawson
Keyword(s):  
Personal Identity ◽  
Radical Change ◽  
Legal Responsibility ◽  
The Difference ◽  
Definition Of ◽  
Over Time

This chapter examines the difference between John Locke's definition of a person [P], considered as a kind of thing, and his definition of a subject of experience of a certain sophisticated sort [S]. It first discusses the equation [P] = [S], where [S] is assumed to be a continuing thing that is able to survive radical change of substantial realization, as well as Locke's position about consciousness in relation to [P]'s identity or existence over time as [S]. It argues that Locke is not guilty of circularity because he is not proposing consciousness as the determinant of [S]'s identity over time, but only of [S]'s moral and legal responsibility over time. Finally, it suggests that the terms “Person” and “Personal identity” pull apart, in Locke's scheme of things, but in a perfectly coherent way.

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