scholarly journals P-wave quarkonium wavefunctions at the origin in the $$ \overline{\mathrm{MS}} $$ scheme

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Hee Sok Chung
Keyword(s):  
First Principles ◽  
Effective Field ◽  
Decay Rates ◽  
P Wave ◽  
Field Theories ◽  
Production Rates ◽  
Long Distance ◽  
Electromagnetic Decay ◽  
Ms Scheme ◽  
Physical Quantities

Abstract We compute P-wave quarkonium wavefunctions at the origin in the $$ \overline{\mathrm{MS}} $$ MS ¯ scheme based on nonrelativistic effective field theories. We include nonperturbative effects from the long-distance behaviors of the potential, while the short-distance behaviors are determined from perturbative QCD. We obtain $$ \overline{\mathrm{MS}} $$ MS ¯ -renormalized P-wave quarkonium wavefunctions at the origin that have the correct scale dependences that are expected from factorization formalisms, so that the dependences on the scheme and scale cancel in physical quantities. This greatly reduces the theoretical uncertainties associated with scheme and scale dependences in predictions of decay and production rates. Based on the calculation of the P-wave wavefunctions at the origin in this work, we make first-principles predictions of electromagnetic decay rates and exclusive electromagnetic production rates of P-wave charmonia and bottomonia, and compare them with measurements.

scholarly journals MS renormalization of S-wave quarkonium wavefunctions at the origin

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Hee Sok Chung
Keyword(s):  
Perturbative Qcd ◽  
Effective Field ◽  
Decay Rates ◽  
S Wave ◽  
Long Distance ◽  
Electromagnetic Decay ◽  
Decay Constants ◽  
Poor Convergence ◽  
Model Independent ◽  
Physical Quantities

Abstract We compute S-wave quarkonium wavefunctions at the origin in the $$ \overline{\mathrm{MS}} $$ MS ¯ scheme based on nonrelativistic effective field theories. We include the effects of nonperturbative long-distance behaviors of the potentials, while we determine the short-distance behaviors of the potentials in perturbative QCD. We obtain $$ \overline{\mathrm{MS}} $$ MS ¯ -renormalized quarkonium wavefunctions at the origin that have the correct scale dependences that are expected from perturbative QCD, so that the scale dependences cancel in physical quantities. Based on the calculation of the wavefunctions at the origin, we make model-independent predictions of decay constants and electromagnetic decay rates of S-wave charmonia and bottomonia, and compare them with measurements. We find that the poor convergence of perturbative QCD corrections are substantially improved when we include corrections to the wavefunctions at the origin in the calculation of decay constants and decay rates.

LONG DISTANCE PHYSICS OF THE HALL FLUID AND THE ANYON SUPERFLUID

1991 ◽  
Vol 05 (10) ◽  
pp. 1629-1639
Author(s):  
A. ZEE
Keyword(s):  
Effective Field Theories ◽  
Effective Field ◽  
Field Theories ◽  
Mathematical Significance ◽  
Long Distance ◽  
Quantum Numbers ◽  
Chern Simons ◽  
Physical Quantities

The long distance physics of the Hall fluid and the anyon superfluid may be described by effective field theories constructed out of the Chern-Simons term. These theories are topological in character and may be of deep mathematical significance. Various physical quantities such as the quantum numbers of the quasiparticles are determined by a matrix appearing in the Chern-Simons term.

scholarly journals Covariant approach to equilibration in effective field theories

2002 ◽  
Vol 80 (2) ◽  
pp. 97-107
Author(s):  
M Burgess ◽  
M E Carrington ◽  
G Kunstatter
Keyword(s):  
Green Function ◽  
Effective Field Theories ◽  
Effective Field ◽  
Field Theories ◽  
Statistical Distributions ◽  
Covariant Approach ◽  
Self Consistent ◽  
Nonequilibrium Theory ◽  
Green Function Approach ◽  
Physical Quantities

The equilibration of two coupled reservoirs is studied using a Green function approach that is suitable for future development with the closed time path method. The problem is solved in two parameterizations, to demonstrate the nontrivial issues of parameterization in both the intermediate steps and the interpretation of physical quantities. We use a covariant approach to find self-consistent solutions for the statistical distributions as functions of time. We show that by formally introducing covariant connections, one can rescale a slowly varying nonequilibrium theory so that it appears to be an equilibrium one, for the purposes of calculation. We emphasize the importance of properly tracking variable redefinitions to correctly interpret physical quantities. PACS Nos.: 11.10-z, 03.70+k, 05.70ln

scholarly journals Extremal effective field theories

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Simon Caron-Huot ◽  
Vincent Van Duong
Keyword(s):  
Scalar Field ◽  
Scattering Amplitudes ◽  
Effective Field Theories ◽  
Convex Hull ◽  
Short Distance ◽  
Large Fraction ◽  
Effective Field ◽  
Field Theories ◽  
Long Distance ◽  
Distance Effects

Abstract Effective field theories (EFT) parameterize the long-distance effects of short-distance dynamics whose details may or may not be known. Previous work showed that EFT coefficients must obey certain positivity constraints if causality and unitarity are satisfied at all scales. We explore those constraints from the perspective of 2 → 2 scattering amplitudes of a light real scalar field, using semi-definite programming to carve out the space of allowed EFT coefficients for a given mass threshold M. We point out that all EFT parameters are bounded both below and above, effectively showing that dimensional analysis scaling is a consequence of causality. This includes the coefficients of s2 + t2 + u2 and stu type interactions. We present simple 2 → 2 extremal amplitudes which realize, or “rule in”, kinks in coefficient space and whose convex hull span a large fraction of the allowed space.

scholarly journals Real-time warm pions from the lattice using an effective theory

2020 ◽  
Vol 35 (33) ◽  
pp. 2030021
Author(s):  
Sourendu Gupta ◽  
Rishi Sharma
Keyword(s):  
Analytic Continuation ◽  
Effective Field ◽  
Field Theories ◽  
Effective Theory ◽  
Explicit Computation ◽  
Crossover Temperature ◽  
Long Distance ◽  
Distance Correlation ◽  
Adequate Information ◽  
Minkowski Space Time

Lattice measurements provide adequate information to fix the parameters of long-distance effective field theories in Euclidean time. Using such a theory, we examine the analytic continuation of long-distance correlation functions of composite operators at finite temperature from Euclidean to Minkowski space–time. We show through an explicit computation that the analytic continuation of the pion correlation function is possible and gives rise to nontrivial effects. Among them is the possibility, supported by lattice computations of Euclidean correlators, that long distance excitations can be understood in terms of (very massive) pions even at temperatures higher than the QCD crossover temperature.

scholarly journals Exceptional nonrelativistic effective field theories with enhanced symmetries

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Tomáš Brauner
Keyword(s):  
Effective Field Theories ◽  
Explicit Construction ◽  
Effective Field ◽  
Field Theories ◽  
Relativistic Case ◽  
Starting Point ◽  
Higher Power ◽  
Mere Presence ◽  
Spatial Rotations

Abstract We initiate the classification of nonrelativistic effective field theories (EFTs) for Nambu-Goldstone (NG) bosons, possessing a set of redundant, coordinate-dependent symmetries. Similarly to the relativistic case, such EFTs are natural candidates for “exceptional” theories, whose scattering amplitudes feature an enhanced soft limit, that is, scale with a higher power of momentum at long wavelengths than expected based on the mere presence of Adler’s zero. The starting point of our framework is the assumption of invariance under spacetime translations and spatial rotations. The setup is nevertheless general enough to accommodate a variety of nontrivial kinematical algebras, including the Poincaré, Galilei (or Bargmann) and Carroll algebras. Our main result is an explicit construction of the nonrelativistic versions of two infinite classes of exceptional theories: the multi-Galileon and the multi-flavor Dirac-Born-Infeld (DBI) theories. In both cases, we uncover novel Wess-Zumino terms, not present in their relativistic counterparts, realizing nontrivially the shift symmetries acting on the NG fields. We demonstrate how the symmetries of the Galileon and DBI theories can be made compatible with a nonrelativistic, quadratic dispersion relation of (some of) the NG modes.

scholarly journals The Swampland Conjectures: A Bridge from Quantum Gravity to Particle Physics

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 273
Author(s):  
Mariana Graña ◽  
Alvaro Herráez
Keyword(s):  
Effective Field Theories ◽  
Quantum Gravity ◽  
Particle Physics ◽  
Effective Field ◽  
Low Energy ◽  
Field Theories ◽  
Neutrino Masses ◽  
Higgs Potential ◽  
Photon Mass ◽  
Effective Theories

The swampland is the set of seemingly consistent low-energy effective field theories that cannot be consistently coupled to quantum gravity. In this review we cover some of the conjectural properties that effective theories should possess in order not to fall in the swampland, and we give an overview of their main applications to particle physics. The latter include predictions on neutrino masses, bounds on the cosmological constant, the electroweak and QCD scales, the photon mass, the Higgs potential and some insights about supersymmetry.

scholarly journals A note on gauge anomaly cancellation in effective field theories

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Ferruccio Feruglio
Keyword(s):  
Effective Field Theories ◽  
Effective Field ◽  
Field Theories ◽  
Anomaly Cancellation ◽  
Charge Assignment ◽  
The Standard Model ◽  
Renormalizable Theory ◽  
Complete Set ◽  
Gauge Anomalies ◽  
Gauge Anomaly

Abstract The conditions for the absence of gauge anomalies in effective field theories (EFT) are rivisited. General results from the cohomology of the BRST operator do not prevent potential anomalies arising from the non-renormalizable sector, when the gauge group is not semi-simple, like in the Standard Model EFT (SMEFT). By considering a simple explicit model that mimics the SMEFT properties, we compute the anomaly in the regularized theory, including a complete set of dimension six operators. We show that the dependence of the anomaly on the non-renormalizable part can be removed by adding a local counterterm to the theory. As a result the condition for gauge anomaly cancellation is completely controlled by the charge assignment of the fermion sector, as in the renormalizable theory.

Sign in / Sign up

Export Citation Format

Share Document