scholarly journals Confinement and Pseudoscalar Glueball Spectrum in the 2 + 1D QCD-Like Theory from the Non-Susy D2 Brane

2022 ◽  
Vol 258 ◽  
pp. 10004
Author(s):  
Adrita Chakraborty
Keyword(s):  
Bound States ◽  
String Tension ◽  
Energy Scale ◽  
Coupling Constant ◽  
Running Coupling ◽  
Monotonically Increasing Function ◽  
Glueball Spectrum ◽  
Holographic Approach ◽  
Increasing Function ◽  
Lattice Approach

We study two important properties of 2+1D QCD, namely confinement and Pseudoscalar glueball spectrum, using holographic approach. The confined state of the bounded quark-antiquark pair occurs in the self-coupling dominated nonperturbative regime, where the free gluons form the bound states, known as glueballs. The gauge theory corresponding to low energy decoupled geometry of isotropic non-supersymmetric D2 brane, which is again similar to the 2+1D YM theory, has been taken into account but in this case the coupling constant is found to vary with the energy scale. At BPS limit, this theory reduces to supersymmetric YM theory. We have considered NG action of a test string and calculate the potential of such confined state located on the boundary. The QCD flux tube tension for large quark-antiquark separation is observed to be a monotonically increasing function of running coupling. The mass spectrum of Pseudoscalar glueball is evaluated numerically from the fluctuations of the axion in the gravity theory using WKB approximation. This produces the mass to be related to the string tension and the levels of the first three energy states. The various results that we obtained quite match with those previously studied through the lattice approach.

scholarly journals The glueball spectrum of SU(3) gauge theory in 3 + 1 dimensions

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Andreas Athenodorou ◽  
Michael Teper
Keyword(s):  
Gauge Theory ◽  
Continuum Limit ◽  
Lattice Gauge Theory ◽  
Rotation Group ◽  
String Tension ◽  
Energy Scale ◽  
Lattice Gauge ◽  
Glueball Spectrum ◽  
Do So ◽  
The Continuum

Abstract We calculate the low-lying glueball spectrum of the SU(3) lattice gauge theory in 3 + 1 dimensions for the range β ≤ 6.50 using the standard plaquette action. We do so for states in all the representations R of the cubic rotation group, and for both values of parity P and charge conjugation C . We extrapolate these results to the continuum limit of the theory using the confining string tension σ as our energy scale. We also present our results in units of the r0 scale and, from that, in terms of physical ‘GeV’ units. For a number of these states we are able to identify their continuum spins J with very little ambiguity. We also calculate the topological charge Q of the lattice gauge fields so as to show that we have sufficient ergodicity throughout our range of β, and we calculate the multiplicative renormalisation of Q as a function of β. We also obtain the continuum limit of the SU(3) topological susceptibility.

A MODEL LAGRANGIAN FOR STRONG INTERACTIONS AT LARGE DISTANCES

1989 ◽  
Vol 04 (03) ◽  
pp. 293-302 ◽  
Author(s):  
MEIUN SHINTANI
Keyword(s):  
Background Field ◽  
String Tension ◽  
Field Method ◽  
Strong Interactions ◽  
Coupling Constant ◽  
Running Coupling ◽  
Free Region ◽  
Running Coupling Constant ◽  
Background Field Method ◽  
The One

On the basis of the massive vector dipole theory as a model for strong interactions at large distances, we compute the counterterm Lagrangian at the one-loop level in the background field method. By smoothly relating the running coupling constant in the confining region to that in the asymptotically free region, we deduce a relationship between the string tension and the QCD scale parameter Λ QCD . With an input data of the string tension, we evaluate the value of Λ QCD . The lower bound to the distances where the dipole theory is valid relies on the number of flavors. The theory seems to be meaningful for six generations or less.

scholarly journals COMPUTATION OF THE SPATIAL STRING TENSION IN HIGH TEMPERATURE SU(2) GAUGE THEORY

1993 ◽  
Vol 04 (06) ◽  
pp. 1179-1193 ◽  
Author(s):  
G. S. BALI ◽  
K. SCHILLING ◽  
J. FINGBERG ◽  
U. M. HELLER ◽  
F. KARSCH
Keyword(s):  
Gauge Theory ◽  
Critical Temperature ◽  
Temperature Dependence ◽  
Scale Parameter ◽  
String Tension ◽  
Coupling Constant ◽  
Running Coupling ◽  
Connection Machine ◽  
Running Coupling Constant ◽  
Sustained Performance

A detailed investigation of the temperature dependence of the spatial string tension σs in SU(2) gauge theory is presented. A sustained performance of 3 GFLOPS on a 64K Connection Machine CM-2 equivalent has been achieved. Scaling of σs between β = 2.5115 and β = 2.74, on large lattices, is demonstrated. Below the critical temperature, Tc, σs remains constant. For temperatures larger than 2Tc the temperature dependence can be parametrized by σs(T) = (0.369 ± 0.014)2g4(T)T2, where g(T) is a 2-loop running coupling constant with the scale parameter determined as ΛT = (0.076 ± 0.013)Tc.

scholarly journals QUANTUM ELECTRODYNAMICS AND CHROMODYNAMICS TREATED THROUGH THOMPSON'S APPROACH

2006 ◽  
Vol 21 (18) ◽  
pp. 3809-3824 ◽  
Author(s):  
CLÁUDIO NASSIF ◽  
P. R. SILVA
Keyword(s):  
Quantum Electrodynamics ◽  
Heuristic Method ◽  
Critical Dimension ◽  
Step Function ◽  
Quark Condensate ◽  
Energy Scale ◽  
Field Theories ◽  
Coupling Constant ◽  
Running Coupling ◽  
Running Coupling Constant

In this work we apply Thompson's method (of the dimensions and scales) to study some features of the Quantum Electrodynamics and Chromodynamics. This heuristic method can be considered as a simple and alternative way to the Renormalization Group approach and when applied to QED-Lagrangian is able to obtain in a first approximation both the running coupling constant behavior of α(μ) and the mass m(μ). The calculations are evaluated only at dc = 4, where dc is the upper critical dimension of the problem, so that we obtain the logarithmic behavior both for the coupling α and the excess of mass Δm on the energy scale μ. Although our results are well known in the vast literature of field theories, the advantage of Thompson's method, beyond its simplicity is that it is able to extract directly from QED-Lagrangian the physical (finite) behavior of α(μ) and m(μ), bypassing hard problems of divergences which normally appear in the conventional renormalization schemes applied to field theories like QED. Quantum Chromodynamics (QCD) is also treated by the present method in order to obtain the quark condensate value. Besides this, the method is also able to evaluate the vacuum pressure at the boundary of the nucleon. This is done by assumming a step function behavior for the running coupling constant of the QCD, which fits nicely to some quantities related to the strong interaction evaluated through the MIT-bag model.

scholarly journals A First-Quantized Model for Unparticles and Gauge Theories around Conformal Window

Universe ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 471
Author(s):  
Nicolas Boulanger ◽  
Fabien Buisseret ◽  
Guillaume Lhost
Keyword(s):  
Bound States ◽  
Gauge Theories ◽  
Mass Operator ◽  
Conformal Symmetry ◽  
Mass Term ◽  
String Tension ◽  
Coupling Constant ◽  
Scalar Particles ◽  
Conformally Invariant ◽  
Invariant Potential

We first quantize an action proposed by Casalbuoni and Gomis in 2014 that describes two massless relativistic scalar particles interacting via a conformally invariant potential. The spectrum is a continuum of massive states that may be interpreted as unparticles. We then obtain in a similar way the mass operator for a deformed action in which two terms are introduced that break the conformal symmetry: a mass term and an extra position-dependent coupling constant. A simple Ansatz for the latter leads to a mass operator with linear confinement in terms of an effective string tension σ. The quantized model is confining when σ≠0 and its mass spectrum shows Regge trajectories. We propose a tensionless limit in which highly excited confined states reduce to (gapped) unparticles. Moreover, the low-lying confined bound states become massless in the latter limit as a sign of conformal symmetry restoration and the ratio between their masses and σ stays constant. The originality of our approach is that it applies to both confining and conformal phases via an effective interacting model.

scholarly journals SU(N) gauge theories in 3+1 dimensions: glueball spectrum, string tensions and topology

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Andreas Athenodorou ◽  
Michael Teper
Keyword(s):  
Topological Charge ◽  
Gauge Theories ◽  
Rotation Group ◽  
String Tension ◽  
Fundamental String ◽  
Running Coupling ◽  
Glueball Spectrum ◽  
Lattice Coupling ◽  
Definition Of ◽  
The Continuum

Abstract We calculate the low-lying glueball spectrum, several string tensions and some properties of topology and the running coupling for SU(N) lattice gauge theories in 3 + 1 dimensions. We do so for 2 ≤ N ≤ 12, using lattice simulations with the Wilson plaquette action, and for glueball states in all the representations of the cubic rotation group, for both values of parity and charge conjugation. We extrapolate these results to the continuum limit of each theory and then to N = ∞. For a number of these states we are able to identify their continuum spins with very little ambiguity. We calculate the fundamental string tension and k = 2 string tension and investigate the N dependence of the ratio. Using the string tension as the scale, we calculate the running of a lattice coupling and confirm that g2(a) ∝ 1/N for constant physics as N → ∞. We fit our calculated values of a√σ with the 3-loop β-function, and extract a value for $$ {\Lambda}_{\overline{MS}} $$ Λ MS ¯ , in units of the string tension, for all our values of N, including SU(3). We use these fits to provide analytic formulae for estimating the string tension at a given lattice coupling. We calculate the topological charge Q for N ≤ 6 where it fluctuates sufficiently for a plausible estimate of the continuum topological susceptibility. We also calculate the renormalisation of the lattice topological charge, ZQ(β), for all our SU(N) gauge theories, using a standard definition of the charge, and we provide interpolating formulae, which may be useful in estimating the renormalisation of the lattice θ parameter. We provide quantitative results for how the topological charge ‘freezes’ with decreasing lattice spacing and with increasing N. Although we are able to show that within our typical errors our glueball and string tension results are insensitive to the freezing of Q at larger N and β, we choose to perform our calculations with a typical distribution of Q imposed upon the fields so as to further reduce any potential systematic errors.

Extinction in the Pigeon after Continuous Reinforcement: Effect of Number of Reinforced Responses

1971 ◽  
Vol 28 (1) ◽  
pp. 331-338 ◽  
Author(s):  
Laurel Furumoto
Keyword(s):  
Animal Studies ◽  
Food Pellet ◽  
Key Peck ◽  
Continuous Reinforcement ◽  
Gm Food ◽  
Free Operant ◽  
Time To Extinction ◽  
Monotonically Increasing Function ◽  
Increasing Functions ◽  
Increasing Function

Number of responses and time to extinction were measured after 3, 10, 1000, 3000, 5000, and 10,000 reinforced key-peck responses during conditioning. Each response was reinforced with a 045-gm. food pellet. The number of responses in extinction was a monotonically increasing function which became asymptotic beyond 1000 reinforced responses. Number of reinforced responses during conditioning significantly affected the number of responses in extinction ( p < .001) but not the time to extinction. The results support the findings of previous free-operant bar-press studies with rats. Free-operant animal studies of extinction after continuous reinforcement have consistently produced monotonically increasing functions and have typically employed relatively small amounts of reinforcement. Amount of reward may be an important parameter determining the shape of the extinction function in the free-operant studies.

Judgment of Temporal Duration of Stimulus Components in a Spatial Sequence

1973 ◽  
Vol 37 (2) ◽  
pp. 619-623
Author(s):  
Suchoon S. Mo ◽  
Michael D. Blaszcszack ◽  
Kathleen Ward
Keyword(s):  
Stimulus Presentation ◽  
Temporal Duration ◽  
Monotonically Increasing Function ◽  
Increasing Function

Judgment of the duration of the stimulus components of tri-grams consisting of consonants was a monotonically increasing function of the letter positions in the sequence of left to right. This tendency was more clearly demonstrated when the frequency of the stimulus presentation exceeded the frequency of the presentation of the stimulus components.

Thermodynamic Performance of an Actual Thermo-Acoustic Refrigeration Micro-Cycle

2012 ◽  
Vol 614-615 ◽  
pp. 64-68
Author(s):  
Tuo Wang ◽  
Feng Wu ◽  
Jin Hua Fei ◽  
Ming Fang Liu
Keyword(s):  
Coefficient Of Performance ◽  
Pressure Amplitude ◽  
Cooling Load ◽  
Acoustic Effect ◽  
Thermodynamic Performance ◽  
Monotonically Increasing Function ◽  
Analytic Expressions ◽  
New Type ◽  
The Relationship ◽  
Increasing Function

Thermo-acoustic refrigerator is a new type of engine, which is based on the thermo-acoustic effect. A new model which expresses as an ellipse in pressure-volume diagram is established to investigate the thermodynamic performance of an actual thermo-acoustic refrigeration micro-cycle. The demarcation points of endothermic processes and exothermic processes in the actual micro-cycle are found. The analytic expressions of the dimensionless cooling load and the coefficient of performance (COP) are deduced. The relationship between the dimensionless cooling load and the COP are investigated by numerical examples. The results show that the dimensionless cooling load is a monotonically increasing function of the COP and the pressure amplitude.

Sign in / Sign up

Export Citation Format

Share Document