scholarly journals Parton degrees of freedom in PDFs from the hadronic tensor and large momentum effective theory

2020 ◽  
Vol 102 (7) ◽  
Author(s):  
Keh-Fei Liu
Keyword(s):  
Degrees Of Freedom ◽  
Effective Theory ◽  
Large Momentum ◽  
Hadronic Tensor

scholarly journals The Spin Structure of the Nucleon

2016 ◽  
Vol 40 ◽  
pp. 1660001
Author(s):  
Xiangdong Ji ◽  
Yong Zhao
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Deeply Virtual Compton Scattering ◽  
Virtual Compton Scattering ◽  
Proton Spin ◽  
Effective Theory ◽  
Large Momentum ◽  
Theory Approach ◽  
The One ◽  
The Relationship

We justify the physical meaning of the spin and orbital angular momentum of free partons in the infinite momentum frame, and discuss the relationship between the Jaffe-Manohar and Ji’s sum rules for proton spin. The parton orbital angular momentum in the Jaffe-Manohar sum rule can be measured through twist-three GPD’s in hard scattering processes such as deeply virtual Compton scattering. Furthermore, we propose that the paton orbital angular momentum as well as the gluon helicity can be calculated in lattice QCD through a large momentum effective theory approach, and provide all the one-loop matching conditions for the proton spin content in perturbative QCD.

scholarly journals Soft-collinear effective theory: BRST formulation

2021 ◽  
Vol 81 (4) ◽  
Author(s):  
Sudhaker Upadhyay ◽  
Bhabani Prasad Mandal
Keyword(s):  
Degrees Of Freedom ◽  
Brst Symmetry ◽  
Symmetry Transformation ◽  
Gauge Condition ◽  
Effective Theory ◽  
Hard Interaction ◽  
Soft Collinear Effective Theory ◽  
Parameter Field ◽  
Definite Structure ◽  
Gauge Conditions

AbstractWe provide a BRST formalism for the soft-collinear effective theory describing interactions of soft and collinear degrees of freedom in the presence of a hard interaction. In particular, we develop a BRST symmetry transformation for SCET theory. We further generalize the BRST formulation by making the transformation parameter field dependent. This establishes a mapping between several SCET actions consistently when defined in different gauge conditions. In fact, a definite structure of gauge-fixed actions corresponding to any particular gauge condition can be generated for SCET theory using our formulation.

Proton Spin Structure from Large Momentum Effective Theory

2017 ◽  
pp. 221-226
Author(s):  
Jian-Hui Zhang ◽  
Xiangdong Ji ◽  
Yong Zhao
Keyword(s):  
Spin Structure ◽  
Proton Spin ◽  
Effective Theory ◽  
Large Momentum ◽  
Proton Spin Structure

scholarly journals INFINITE STATISTICS, SYMMETRY BREAKING AND COMBINATORIAL HIERARCHY

2009 ◽  
Vol 24 (18) ◽  
pp. 1425-1435 ◽  
Author(s):  
VLADIMIR SHEVCHENKO
Keyword(s):  
Symmetry Breaking ◽  
Mechanical Model ◽  
Degrees Of Freedom ◽  
High Energy ◽  
Low Energy ◽  
Effective Theory ◽  
Quantum Mechanical ◽  
Hierarchy Problem ◽  
Induced Gravity ◽  
Large Numbers

The physics of symmetry breaking in theories with strongly interacting quanta obeying infinite (quantum Boltzmann) statistics known as quons is discussed. The picture of Bose/Fermi particles as low energy excitations over nontrivial quon condensate is advocated. Using induced gravity arguments, it is demonstrated that the Planck mass in such low energy effective theory can be factorially (in number of degrees of freedom) larger than its true ultraviolet cutoff. Thus, the assumption that statistics of relevant high energy excitations is neither Bose nor Fermi but infinite can remove the hierarchy problem without necessity to introduce any artificially large numbers. Quantum mechanical model illustrating this scenario is presented.

scholarly journals Partition Function in One, Two, and Three Spatial Dimensions from Effective Lagrangian Field Theory

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Christoph P. Hofmann
Keyword(s):  
Partition Function ◽  
Degrees Of Freedom ◽  
Spatial Dimension ◽  
Lagrangian Method ◽  
Point Of View ◽  
Low Energy ◽  
Effective Theory ◽  
Goldstone Bosons ◽  
Effective Lagrangian ◽  
Spatial Dimensions

The systematic effective Lagrangian method was first formulated in the context of the strong interaction; chiral perturbation theory (CHPT) is the effective theory of quantum chromodynamics (QCD). It was then pointed out that the method can be transferred to the nonrelativistic domain—in particular, to describe the low-energy properties of ferromagnets. Interestingly, whereas for Lorentz-invariant systems the effective Lagrangian method fails in one spatial dimension (ds=1), it perfectly works for nonrelativistic systems in ds=1. In the present brief review, we give an outline of the method and then focus on the partition function for ferromagnetic spin chains, ferromagnetic films, and ferromagnetic crystals up to three loops in the perturbative expansion—an accuracy never achieved by conventional condensed matter methods. We then compare ferromagnets in ds=1, 2, 3 with the behavior of QCD at low temperatures by considering the pressure and the order parameter. The two apparently very different systems (ferromagnets and QCD) are related from a universal point of view based on the spontaneously broken symmetry. In either case, the low-energy dynamics is described by an effective theory containing Goldstone bosons as basic degrees of freedom.

scholarly journals RUNNING MASS OF THE b-QUARK IN QCD AND SUSY QCD

2007 ◽  
Vol 22 (29) ◽  
pp. 5245-5277 ◽  
Author(s):  
A. V. BEDNYAKOV
Keyword(s):  
Numerical Analysis ◽  
Degrees Of Freedom ◽  
Effective Theory ◽  
Supersymmetric Extension ◽  
Heavy Particles ◽  
Advantages And Disadvantages ◽  
The Difference ◽  
B Quark

The running mass of the b-quark defined in [Formula: see text]-scheme is one of the important parameters of SUSY QCD. To find its value, it should be related to some known experimental input. In this paper, the b-quark running mass defined in nonsupersymmetric QCD is chosen for determination of the corresponding parameter in SUSY QCD. The relation between these two quantities is found by considering five-flavor QCD as an effective theory obtained from its supersymmetric extension. A numerical analysis of the calculated two-loop relation and its impact on the MSSM spectrum is discussed. Since for nonsupersymmetric models [Formula: see text]-scheme is more natural than [Formula: see text], we also propose a new procedure that allows one to calculate relations between [Formula: see text]- and [Formula: see text]-parameters. Unphysical ε-scalars that give rise to the difference between the above-mentioned schemes are assumed to be heavy and decoupled in the same way as physical degrees of freedom. By means of this method it is possible to "catch two rabbits," i.e. decouple heavy particles and turn from [Formula: see text] to [Formula: see text], at the same time. An explicit two-loop example of [Formula: see text] transition is given in the context of QCD. The advantages and disadvantages of the method are briefly discussed.

CHARMONIUM NON-POTENTIAL EXCITATIONS

1990 ◽  
Vol 05 (09) ◽  
pp. 685-692
Author(s):  
V. YU. BORUE ◽  
S.B. KHOKHLACHEV
Keyword(s):  
Heavy Quark ◽  
Ground State ◽  
Degrees Of Freedom ◽  
Effective Theory

Within the framework of an effective theory of quantum gluodynamics formulated earlier in terms of the glueball degrees of freedom, the excitations of gluon bunch formed by heavy quark and antiquark are considered. It is shown that these excitations correspond to the vibration of the gluon bunch shape and lie nearly 800 MeV higher than the charmonium ground state. The consequences of the existence of these excitations are discussed.

CONSTRAINED FERMIONIC MODELS IN NON-TRIVIAL TOPOLOGICAL SECTORS

1992 ◽  
Vol 07 (24) ◽  
pp. 2179-2188 ◽  
Author(s):  
ENRIQUE F. MORENO
Keyword(s):  
Path Integral ◽  
Degrees Of Freedom ◽  
Central Charge ◽  
Coulomb Gas ◽  
Effective Theory ◽  
Fermionic Model ◽  
Topological Sector ◽  
Integral Treatment ◽  
Background Charge

We study a constrained fermionic model involving non-trivial topological gauge configurations. After a path-integral treatment of the topologically trivial degrees of freedom we show that the resulting effective theory is equivalent to a Coulomb gas theory with a "background charge" at infinity plus a b, c ghost system. The Virasoro central charge of the theory is found to be independent of the topological sector.

scholarly journals Lattice Clifford fractons and their Chern-Simons-like theory

2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Weslei Fontana ◽  
Pedro Gomes ◽  
Claudio Chamon
Keyword(s):  
Clifford Algebra ◽  
Degrees Of Freedom ◽  
Quantum Hall ◽  
Effective Theory ◽  
Matrix Representations ◽  
Quantum Hall States ◽  
Dirac Matrix ◽  
Spatial Dimensions ◽  
K Matrix ◽  
Chern Simons

We use Dirac matrix representations of the Clifford algebra to build fracton models on the lattice and their effective Chern-Simons-like theory. As an example, we build lattice fractons in odd D spatial dimensions and their (D+1) spacetime dimensional effective theory. The model possesses an anti-symmetric K matrix resembling that of hierarchical quantum Hall states. The gauge charges are conserved in sub-dimensional manifolds which ensures the fractonic behavior. The construction extends to any lattice fracton model built from commuting projectors and with tensor products of spin-1/2 degrees of freedom at the sites.

scholarly journals Large-momentum effective theory

2021 ◽  
Vol 93 (3) ◽  
Author(s):  
Xiangdong Ji ◽  
Yizhuang Liu ◽  
Yu-Sheng Liu ◽  
Jian-Hui Zhang ◽  
Yong Zhao
Keyword(s):  
Effective Theory ◽  
Large Momentum
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