πNtransition distribution amplitudes: Their symmetries and constraints from chiral dynamics

نویسندگان
چکیده

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

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Unitarity constraints on chiral perturbative amplitudes

Low lying scalar resonances emerge as a necessary part to adjust chiral perturbation theory to experimental data once unitarity constraint is taken into consideration. I review recent progress made in this direction in a model independent approach. Also I briefly review studies on the odd physical properties of these low lying scalar resonances, including in the γγ → π+π−, π0π0 processes. Low l...

متن کامل

Positivity Constraints on Chiral Perturbation Theory Pion-Pion Scattering Amplitudes

We test the positivity property of the chiral perturbation theory (ChPT) pion-pion scattering amplitudes within the Mandelstam triangle. In the one-loop approximation, O(p4), the positivity constrains only the coefficients b3 and b4, namely one obtains that b4 and the linear combination b3 + 3b4 are positive quantities. The two-loops approximation gives inequalities involving all the six arbitr...

متن کامل

Proton Structure Functions from Chiral Dynamics and QCD Constraints

The spin fractions and deep inelastic lepton structure functions of the proton are analyzed using chiral field theory involving Goldstone bosons. A detailed comparison with recent chiral models sheds light on their successful description of the spin fractions of the proton as being due to neglecting helicity non-flip chiral transitions. This approximation is valid for zero mass but not for cons...

متن کامل

Pion Generalized Distribution Amplitudes in the Nonlocal Chiral Quark Model

We use a simple, instanton motivated, nonlocal chiral quark model to calculate pion Generalized Distribution Amplitudes (GDAs). The nonlo-cality appears due to the momentum dependence of the constituent quark mass, which we take in a form of a generalized dipole formula. With this choice all calculations can be performed directly in the Minkowski space and the sensitivity to the shape of the cu...

متن کامل

4D Scattering Amplitudes and Asymptotic Symmetries from 2D CFT

We reformulate the scattering amplitudes of 4D flat space gauge theory and gravity in the language of a 2D CFT on the celestial sphere. The resulting CFT structure exhibits an OPE constructed from 4D collinear singularities, as well as infinite-dimensional Kac-Moody and Virasoro algebras encoding the asymptotic symmetries of 4D flat space. We derive these results by recasting 4D dynamics in ter...

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

ژورنال

عنوان ژورنال: Physical Review D

سال: 2011

ISSN: 1550-7998,1550-2368

DOI: 10.1103/physrevd.84.074014