Pion and photon light–cone wave functions from the instanton vacuum
نویسندگان
چکیده
The leading–twist wave functions of the pion and the photon at a low normalization point are calculated in the effective low–energy theory derived from the instanton vacuum. The pion wave function is found to be close to the asymptotic one, consistent with the recent CLEO measurements. The photon wave function is non-zero at the endpoints. This different behavior is a consequence of the momentum dependence of the dynamical quark mass suggested by the instanton vacuum. We comment on the relation of meson wave functions and off-forward parton distributions in this model. PACS: 12.38.Lg, 13.60.Fz, 13.60.Le
منابع مشابه
Instanton Model of Light Hadrons: from Low to High Energies
Instanton liquid model being effective model of the QCD vacuum describes well the hadrons at low as well at intermediate energies. Thus, contact with perturbative QCD results is possible providing the unique information about the quark-gluon distribution functions in the QCD vacuum and hadrons at low energy normalization point. As an illustrative example we consider the pion transition form fac...
متن کاملLeading-twist pion and kaon distribution amplitudes in the gauge-invariant nonlocal chiral quark model from the instanton vacuum
We investigate the leading-twist light-cone distribution amplitudes for the pion and kaon based on the gauge-invariant nonlocal chiral quark model from the instanton vacuum in the presence of external axial-vector currents. We find that the nonlocal contribution from the gauge invariance has much effects on the pion distribution amplitudes, while it changes mildly the kaon ones. We also study t...
متن کاملLight–Cone Quantization: Foundations and Applications
These lecture notes review the foundations and some applications of light– cone quantization. First I explain how to choose a time in special relativity. Inclusion of Poincaré invariance naturally leads to Dirac’s forms of relativistic dynamics. Among these, the front form, being the basis for light–cone quantization, is my main focus. I explain a few of its peculiar features such as boost and ...
متن کاملPreliminaries on a Lattice Analysis of The Pion Light - cone Wave function : a Partonic Signal ?
We present the first attempt of a new method to compute the pion light-cone wave function (LCWF) on the lattice. We compute the matrix element between the pion and the vacuum of a non-local operator: the propagator of a " scalar quark " (named for short " squark "). A theoretical analysis shows that for some kinematical conditions (energetic pion and hard squark) this matrix element depends dom...
متن کاملThreshold Pion Production at Large Momentum Transfers
We consider threshold pion electroproduction on a proton target for photon virtualities in the region 1 − 10 GeV. The S-wave multipoles at threshold, E0+ and L0+, are calculated using light-cone sum rules.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 1998