Absence of anomalous counterterms in the first order in the coupling constant of the first variational derivative of the quantum expectation value of the P exponential

1981 ◽  
Vol 48 (2) ◽  
pp. 677-685 ◽  
Author(s):  
A. G. Chernikov
Keyword(s):  
Coupling Constant ◽  
Variational Derivative ◽  
Expectation Value ◽  
First Order

scholarly journals OPERATOR-PRODUCT EXPANSION AND ANALYTICITY

1999 ◽  
Vol 14 (30) ◽  
pp. 4819-4840
Author(s):  
JAN FISCHER ◽  
IVO VRKOČ
Keyword(s):  
Operator Product Expansion ◽  
Deflection Angle ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Operator Product ◽  
Coupling Constant ◽  
Expectation Value ◽  
Euclidean Region ◽  
The Deflection Angle ◽  
Class Of Functions

We discuss the current use of the operator-product expansion in QCD calculations. Treating the OPE as an expansion in inverse powers of an energy-squared variable (with possible exponential terms added), approximating the vacuum expectation value of the operator product by several terms and assuming a bound on the remainder along the Euclidean region, we observe how the bound varies with increasing deflection from the Euclidean ray down to the cut (Minkowski region). We argue that the assumption that the remainder is constant for all angles in the cut complex plane down to the Minkowski region is not justified. Making specific assumptions on the properties of the expanded function, we obtain bounds on the remainder in explicit form and show that they are very sensitive both to the deflection angle and to the class of functions considered. The results obtained are discussed in connection with calculations of the coupling constant αs from the τ decay.

scholarly journals Electroweak phase transition with three phases in the SU(2)1 ⊗ SU(2)2 ⊗ U(1)Y model

2019 ◽  
Vol 34 (15) ◽  
pp. 1950073
Author(s):  
Vo Quoc Phong ◽  
Minh Anh Nguyen
Keyword(s):  
Phase Transition ◽  
Coupling Constant ◽  
Gauge Bosons ◽  
Electroweak Phase Transition ◽  
First Order ◽  
First Order Phase Transition ◽  
200 Gev ◽  
Strength Formula ◽  
The Masses ◽  
First Order Phase

Our analysis shows that SM-like electroweak phase transition (EWPT) in the [Formula: see text] (2-2-1) model is a first-order phase transition at the 200 GeV scale (the SM scale). Its strength [Formula: see text] is about 1–2.7 and the masses of new gauge bosons are larger than 1.7 TeV when the second VEV is larger than 535 GeV in a three-stage EWPT scenario and the coupling constant of [Formula: see text] group must be larger than 2. Therefore, this first-order EWPT can be used to fix VEVs and the coupling constant of the gauge group in electroweak models.

Correlated Squeezed State Approach for Complex Phonon Coupling in a Tunnelling System

1997 ◽  
Vol 11 (11) ◽  
pp. 485-492
Author(s):  
S. Baskoutas ◽  
P. Papanikolaou
Keyword(s):  
Probability Density ◽  
Reduction Factor ◽  
State System ◽  
Boson Field ◽  
Coupling Constant ◽  
Phonon Coupling ◽  
Squeezed State ◽  
Expectation Value ◽  
The Real

In the present paper we propose a method of studying a two-state system coupled linearly to a boson field with complex coupling in a correlated squeezed state approach. The complex coupling leads to the initiation of complex probability density with complex statistical averages. Exploiting the biorthonormal formalism we obtain the analytical forms of the complex expectation value E of H as well as the complex tunneling reduction factor. As it is seen from our results the localization–delocalization transition of the tunneling particle is modified for small values of the real part of the coupling constant in comparison with the conventional (g real) correlated squeezed state approach.

Berechnung der Spin-Spin-Koppelkonstante von HD mit nichtsingulärem Kontaktoperator / Calculation of the NMR Coupling Constant in HD by Using a Nonsingitlar Contact Operator

1973 ◽  
Vol 28 (11) ◽  
pp. 1866-1868 ◽  
Author(s):  
W. Sänger ◽  
J. Voitländer
Keyword(s):  
Delta Function ◽  
Spin Coupling ◽  
Coupling Constant ◽  
Coupling Energy ◽  
First Order ◽  
Order Energy ◽  
Spatial Part ◽  
Fermi Contact ◽  
Contact Operator ◽  
Spin Spin Coupling

The Fermi contact contribution to the nuclear spin-spin coupling constant of HD is calculated variationally. Instead of the delta-function a modified nonsingular contact spatial part is used. The self-coupling energy becomes finite and the variation of the whole second-order energy due to a non- singular first-order perturbed trial function can be carried out.

EMISSION SPECTRUM OF A TWO-LEVEL ATOM IN AN OPTOMECHANICAL CAVITY

2013 ◽  
Vol 27 (31) ◽  
pp. 1350226
Author(s):  
JI HUI TENG ◽  
HONG FU WANG ◽  
XUE XI YI
Keyword(s):  
Emission Spectrum ◽  
Single Atom ◽  
Coupling Constant ◽  
Cavity Field ◽  
First Order ◽  
Level Atom ◽  
Optomechanical Cavity ◽  
Cavity Mirror

The emission spectrum of a single atom inside an optomechanical cavity is studied in this paper. Our model consists of a single two-level atom coupled to a cavity with a moving end mirror. We numerically calculate the emission spectrum of the atom, taking the effect of the moving mirror into account. The dependence of the spectrum peak on the coupling between the moving mirror and the cavity field is analyzed. For weak cavity-mirror couplings, we expand the spectrum up to the first order of the coupling constant.

scholarly journals NAMBU-JONA-LASINIO MODEL IN CURVED SPACE-TIME

1993 ◽  
Vol 08 (22) ◽  
pp. 2117-2123 ◽  
Author(s):  
T. INAGAKI ◽  
T. MUTA ◽  
S.D. ODINTSOV
Keyword(s):  
Proper Time ◽  
Space Time ◽  
Leading Order ◽  
Coupling Constant ◽  
Normal Coordinate ◽  
Dynamical Mass ◽  
Curved Space ◽  
First Order ◽  
First Order Phase Transition ◽  
First Order Phase

The phase structure of Nambu-Jona-Lasinio model with N-component fermions in curved space-time is studied in the leading order of the 1/N expansion. The effective potential for composite operator [Formula: see text] is calculated by using the normal coordinate expansion in the Schwinger proper-time method. The existence of the first order phase transition caused by the change of the space-time curvature is confirmed and the dynamical mass of the fermion is calculated as a simultaneous function of the curvature and the four-fermion coupling constant. The phase diagram in the curvature and the coupling constant is obtained.

scholarly journals Electroweak Phase Transitions in Einstein’s Static Universe

2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
M. Gogberashvili
Keyword(s):  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Electroweak Phase Transition ◽  
Static Universe ◽  
Expectation Value ◽  
First Order ◽  
Higgs Vacuum ◽  
The Standard Model ◽  
Effective Reduction ◽  
New Phase

We suggest using Einstein’s static universe metric for the metastable state after reheating, instead of the Friedman-Robertson-Walker spacetime. In this case, strong static gravitational potential leads to the effective reduction of the Higgs vacuum expectation value, which is found to be compatible with the Standard Model first-order electroweak phase transition conditions. Gravity could also increase the CP-violating effects for particles that cross the new phase bubble walls and thus is able to lead to the successful electroweak baryogenesis scenario.

scholarly journals DECAY COUPLING CONSTANT SUM RULES FOR TETRAQUARKS $T[(\bar{Q}q)(Q\bar{q})]$ WITH BROKEN SU(3) SYMMETRY

2013 ◽  
Vol 28 (06) ◽  
pp. 1350015
Author(s):  
V. GUPTA ◽  
G. SÁNCHEZ-COLÓN ◽  
S. RAJPOOT
Keyword(s):  
Symmetry Breaking ◽  
Sum Rules ◽  
Coupling Constants ◽  
Coupling Constant ◽  
First Order

For tetraquarks of the form [Formula: see text] we give sum rules for their decay coupling constants, taking into account the SU(3) symmetry breaking interactions to first-order.

13C and some 15N N.M.R. spectra of heteroaromatic molecules containing bridgehead nitrogen atoms

1980 ◽  
Vol 33 (3) ◽  
pp. 499 ◽  
Author(s):  
AJ Jones ◽  
P Hanisch ◽  
ML Heffernan ◽  
GM Irvine
Keyword(s):  
Electronic Structures ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Coupling Constant ◽  
Methyl Substitution ◽  
First Order ◽  
Degree Of Aromaticity ◽  
Bridgehead Nitrogen ◽  
High Degree ◽  
Free Pair

The carbon-13 and (in part) nitrogen-15 chemical shifts of 1,2,3- triazaindolizine and seven three ringed analogues of indolizine have been analysed and enable deductions to be made concerning the extent that the free pair of electrons on the bridgehead nitrogen atom contributes to the delocalized electronic structures. Analogies between these molecules and indolizine are noted in that all the systems possess a high degree of aromaticity. Additivity relationships for nitrogen and methyl substitution are compared with those previously reported for other heteroaromatic molecules. Comparison of previously published 100-MHz and the present-work 270-MHz proton n.m.r. results enabled 13C spectral assignments to be confirmed by selective 1H irradiation experiments, since coupling constant analyses did not provide unambiguous assignments in all cases. One-, two-, three- and four-bond 13C-1H coupling constants are reported for most carbon atoms where first-order spectral analysis was possible. Several examples of non-first-order behaviour are presented and attempts to reconcile the occurrence of this behaviour are outlined.

scholarly journals Extended Conformal Symmetry of the One-Dimensional Bose Gas

1997 ◽  
Vol 12 (29) ◽  
pp. 2153-2159 ◽  
Author(s):  
Milena Maule ◽  
Stefano Sciuto
Keyword(s):  
Cartan Subalgebra ◽  
Conformal Symmetry ◽  
Hard Core ◽  
Bose Gas ◽  
Effective Hamiltonian ◽  
Coupling Constant ◽  
Free Fermions ◽  
One Dimensional ◽  
First Order ◽  
The One

We show that the low-lying excitations of the one-dimensional Bose gas are described, at all orders in a 1/N expansion and at the first order in the inverse of the coupling constant, by an effective Hamiltonian written in terms of an extended conformal algebra, namely the Cartan subalgebra of the [Formula: see text] algebra. This enables us to construct the first interaction term which corrects the Hamiltonian of the free fermions equivalent to a hard-core boson system.

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