The Fifth Conference “ Nuclear Science and Its Application”, 14-17 October 2008
DIFFERENTIAL CROSS SECTIONS OF CARBON ISOTOPES 9C - 15C
INCIDENT ON A PROTON IN THE FRAMEWORK OF DIFFRACTION
APPROACH
E.T. IBRAEVA1. O. IM A M BEK O V 2, G. NU RBAKOVA2, A.M . ZH U SU PO V 2 ‘The Institute o f Nuclear Physics o f National Nuclear Center, Alma-Ata, Kazakhstan 2 al-Farabi Kazakh National University, Department o f Physics, Alma-Ata, Kazakhstan
M ost o f presented carbon isotopes are neutron rich unstable b y (1-decay nuclei: 9’10I1C by P+ and 1415C by (5% w ith life tim e from 0.127 sec. for 9C to 5730 years for 14C. The structure o f carbon isotopes has attracted m uch attention as experim ental inform ation already accum ulated tow ards its neutron dripline as w ell as data are expected to be provided by radioactive ion beam facilities such as RIK EN (Gapan) and GSI (France).
Experim ents w ith such nuclei are conventionally set w ithin inverse kinem atics w ith proton as target for incident beam o f instable nuclei produced in nuclear reactions at accelerator.
The new articles [1 ,2 ] were represented system atically analyze total reaction cross sections o f carbon isotopes on a proton [1] and on a !2C [2] targets for wide range o f incident energy. F o r the calculation o f the cross sections w ere taken the G lauber approxim ation. It is vital to find a consistent param etrization o f the pN -scattering amplitude which have successfully reproduced the data on reaction cross section. The param eters w ere found in [1, 2] we used in our calculations.
In the present w ork we calculate differential cross section for proton scattering at this nucleus w ithin inverse kinem atics at energy from 100 to 1000 G eV /nucleon w ithin G lauber diffraction approach, which enables to calculate quite precisely the characteristics o f elastic scattering for hadrons at nuclei at high and interm ediate energies.
To describe the intristic structure o f carbon isotopes we used the wave function in m any body shell m odel [3] for 1011,415C nuclei and wave function in three-body 7B e-p-p-m odel for 9C nucleus [4].
This theory enables us to study the scattering process m icroscopically, i.e. to evaluate contributions from scattering different m ultiplicities in the section and to understand the influence o f nuclear structure on this section. U pon calculations o f the contributions into differential cross section from the first three term s in multiple scattering at energy 1.0 G eV /nucleon w e have show n that single collisions prevail at the sm allest scattering angles less than 0 < J2, w hile double collisions - in the region o f the second m axim um o f the cross section (2O>0 > 12°) and triple ones - in the region o f the third m axim um at 0 > 20°. A t overlapping o f different scattering
Section II. Basic Problem s O f N uclear Physics
The Fifth Conference “ Nuclear Science and Its Application”, 14-17 October 2008
m ultiplicities there appear characteristic interference m inim a in the differential cross section since the m ultiple scattering series consist o f term s w ith alternating signs and those term s w ith opposite signs decrease the totals.
In that way using G lauber diffraction approach we can calculate the differential cross section for scattering protons from instable carbon isotopes in inverse kinem atics. This theory enabled us to study scattering at m acroscopic level, i.e. to evaluate contributions into the section from different scattering m ultiplicities and to understand the role o f nuclear structure in this process.
1. B. A bu-Ibrahim et al. arX iv:0710.4193vl [nucl-th] 2007. 2. W. Horiuchi et al Phys.Rev. C 75, 044607 (2007).
3. A.N. Boyarkina The structure o f nuclei o f Ip-shell. Moscow. 1970.
4. M.A. Zhusupov, E.T. Ibraeva Izv. Rus. Akad. Nauk. Ser.Fiz. 2008 (in published).
