Four - point correlator constraints on electromagnetic chiral parameters and resonance effective

نویسنده

  • B. Moussallam
چکیده

We pursue the analysis of a set of generalized DGMLY sum rules for the electromagnetic chiral parameters at order e2p2 and discuss implications for effective Lagrangians with resonances. We exploit a formalism in which charge spurions are introduced and treated as sources. We show that no inconsistency arises from anomalies up to quadratic order in the spurions. We focus on the sum rules associated with QCD 4-point correlators which were not analyzed in detail before. Convergence properties of the sum rules are deduced from a general analysis of the form of the counterterms in the presence of electromagnetic spurions. Following the approach in which vector and axial-vector resonances are described with antisymmetric tensor fields and have a chiral order, we show that the convergence constraints are violated at chiral order four and can be satisfied by introducing a set of terms of order six. The relevant couplings get completely and uniquely determined from a set of generalized Weinberg sumrule relations. An update on the corrections to Dashen’s low-energy theorem is given. Supported in part by IFCPAR contract 2504-1, by the European Union TMR network, Contract No. HPRN-CT-2002-00311 (EURIDICE) and by the Department of Science and Technology, Government of India.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Chiral Symmetry Restoration in Hadron

The evidence and the theoretical justification of chiral symmetry restoration in high-lying hadrons is presented. I. CHIRAL SYMMETRY RESTORATION OF THE SECOND KIND It has recently been suggested that the parity doublet structure seen in the spectrum of highly excited baryons may be due to effective chiral symmetry restoration for these states [1]. This phenomenon can be understood in very gener...

متن کامل

Quasi-Static Theory for Uniaxial Chiral Omega Media

The problem of unbounded uniaxial chiral omega media in the presence of both static electric and magnetic point charges is investigated. For this purpose scalar electric and magnetic potentials in these media are introduced. Using these potentials, the corresponding electric and magnetic fields are determined. The similar problem of static electric and magnetic current sources with the goal of ...

متن کامل

Singlet V AṼ correlator within the instanton vacuum model

The correlator of singlet axial-vector and vector currents in the external electromagnetic field is studied within the instanton liquid model of QCD vacuum. In the chiral limit we calculate the longitudinal w (0) L and transversal w (0) T with respect to axial-vector index invariant amplitudes at arbitrary momentum transfer q. It is demonstrated how the anomalous longitudinal part of the correl...

متن کامل

Worldsheet four-point functions in AdS3/CFT2

We calculate some extremal and non-extremal four-point functions on the sphere of certain chiral primary operators for strings on AdS3 ×S3 × T . The computation is done for small values of the spacetime cross-ratio where global SL(2) and SU(2) descendants may be neglected in the intermediate channel. Ignoring also current algebra descendants, we find that in the non-extremal case the integrated...

متن کامل

0 v 1 3 0 M ar 1 99 5 On a subtle point of sum rules calculations : toy model

We consider a two-point correlator in massless φ 3 model within the ladder approximation . The spectral density of the correlator is known explicitly and does not contain any resonances. Meanwhile making use of the standard sum rules technique with a simple " resonance + continuum " model of the spectrum allows to predict parameters of the " resonance " very accurately in the sense that all nec...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2004