Virtual Compton scattering off the nucleon at low energies.

نویسندگان

  • Scherer
  • Korchin
  • Koch
چکیده

We investigate the low-energy behavior of the four-point Green’s function Γ describing virtual Compton scattering off the nucleon. Using Lorentz invariance, gauge invariance, and crossing symmetry, we derive the leading terms of an expansion of the operator in the four-momenta q and q′ of the initial and final photon, respectively. The model-independent result is expressed in terms of the electromagnetic form factors of the free nucleon, i.e., on-shell information which one obtains from electron-nucleon scattering experiments. Model-dependent terms appear in the operator at O(qαq ′ β), whereas the orders O(qαqβ) and O(q ′ αq ′ β) are contained in the low-energy theorem for Γ μν , i.e., no new parameters appear. We discuss the leading terms of the matrix element and comment on the use of on-shell equivalent electromagnetic vertices in the calculation of “Born terms” for virtual Compton scattering. 13.40.Gp,13.60.Fz,14.20.Dh Typeset using REVTEX ∗Supported by Deutsche Forschungsgemeinschaft

برای دانلود رایگان 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 dynamics of rare eta decays and virtual Compton scattering off the nucleon

Two different topics relevant for DAΦNE and CEBAF, respectively, are covered. First we analyze the rare radiative eta decay mode η → ππγγ within the framework of chiral perturbation theory at O(p 4). We then discuss virtual Compton scattering off the nucleon at low energies. Predictions for the two spin-independent generalized polarizabilities are shown.

متن کامل

Virtual Compton Scattering—Generalized Polarizabilities of Nucleons and Pions

Virtual Compton scattering off nucleons and pions at low energies is discussed. Predictions for the generalized polarizabilities of the nucleon are presented within the framework of heavy-baryon chiral perturbation theory and the linear sigma model. First results for the generalized polarizabilities of the charged pion in chiral perturbation theory at O(p) are shown.

متن کامل

Chiral Dynamics of Rare Eta Decays and Virtual Compton Scattering Oo the Nucleon

Two diierent topics relevant for DAANE and CEBAF, respectively, are covered. First we analyze the rare radiative eta decay mode ! within the framework of chiral perturbation theory at O(p 4). We then discuss virtual Compton scattering oo the nucleon at low energies. Predictions for the two spin-independent generalized polarizabilities are shown.

متن کامل

Real and Virtual Compton Scattering off the Nucleon

A review is given of the very recent developments in the fields of real and virtual Compton scattering off the nucleon. Both real and virtual Compton scattering reactions are discussed at low outgoing photon energy where one accesses polarizabilities of the nucleon. The real Compton scattering at large momentum transfer is discussed which is asymptotically a tool to obtain information on the va...

متن کامل

Virtual Compton Scattering

Virtual Compton Scattering off the proton: γ∗p → γp is a new field of investigation of nucleon structure. Several dedicated experiments have been performed at low c.m. energy and various momentum transfers, yielding specific information on the proton. This talk reviews the concept of nucleon Generalized Polarizabilities and the present experimental status. Virtual Compton Scattering (VCS) off t...

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

عنوان ژورنال:
  • Physical review. C, Nuclear physics

دوره 54 2  شماره 

صفحات  -

تاریخ انتشار 1996