Weak and Electroproduction of Nucleon Resonances in the Harmonic Oscillator Quark Model

نویسندگان

  • Tariq Abdullah
  • Francis E. Close
چکیده

Using the model that the baryons are composed of quarks with harmonic interactions, we compute cross-sections for high energy neutrinos and electrons to excite the nucleon to the resonance states with masses below 1.9 GeV. The frame dependence of the nonrelativistic quark model results is emphasized and discrepancies between some previous model calculations of electroproduction form factors and data are shown to be due to the frame chosen. For neutrino-production, the model predicts that asignificant excitation of the second and third resonance regions will be seen from neutrons, but with proton targets only the A(1236) excitation will be observed. An interesting result of the electroproduction calculation is the prediction that the P11(1470), while suppressed at small t (and hence in photoproduction) will dominate over the S11(1556) and D13(1520) at large t 21. ~(G~V/C)~.

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

A QUARTIC POTENTIAL FOR THE NUCLEONIC QUARKS

We assume that each valence quark in a nucleon is in a phenomenological modified harmonic oscillator potential of the form: ( l+yo) (ar +br+cr +dr ), where a, b, c and d are constants and ? is one of the Dirac matrices. Then by making use of a suitable ansatz, the Dirac equation has a very simple solution which is exact. We then have calculated the static properties of the nucleon in the ...

متن کامل

Helicity Structure of Nucleon Resonance Electroproduction and the Symmetric Quark Model*

The symmetric quark model with harmonic forces is shown to lead to a rapid change with q2 of the helicity structure for elec troproduction of the second (D13) and third (F15) nucleon resonances. Preliminary results of coincidence measurements of pi-zero electroproduction in the resonance region are found to disagree with this prediction. Some further experimental tests and theoretical consequen...

متن کامل

بررسی و مطالعه توابع ساختار و توزیع زاویه‌ای پراکندگی لپتون‌ها از هسته‌های 40Ca و 56Fe

 In this paper, we calculate nuclear structure function and EMC effect of 40Ca and 56Fe nuclei. To achive the goals, we consider Fermi motion and binding energy contrbiution in the harmonic oscillator model. In this model, harmonic oscillator parameter ħω related to shells root mean square radius and for free nucleon structure functions, is obtained from GRV’s free nucleon structure functions. ...

متن کامل

Electroproduction of K mesons at CLAS

Quark models predict baryon resonances [1] that have not yet been observed via strong interactions. These resonances could be detected via electroand photoproduction of strange mesons. Of special interest are the nucleon resonances N which some of them could couple strongly to KΛ and KΣ [2]. Moreover, higher mass nucleon resonances could favor decaying into KΣ, near threshold. Using a quark-pai...

متن کامل

Dilepton decays of nucleon resonances and dilepton production cross sections in proton-proton collisions

Relativistic, kinematically complete phenomenological expressions for the dilepton decay rates of nucleon resonances with arbitrary spin and parity are derived in terms of the magnetic, electric, and Coulomb transition form factors. The dilepton decay rates of the nucleon resonances with masses below 2 GeV are estimated using the extended vector meson dominance (eVMD) model for the transition f...

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:

دوره   شماره 

صفحات  -

تاریخ انتشار 1999