Physics – Nuclear Physics – Nuclear Theory
Scientific paper
2001-05-22
Nucl.Phys. A697 (2002) 255-276
Physics
Nuclear Physics
Nuclear Theory
18 pages, 8 figures
Scientific paper
10.1016/S0375-9474(01)01231-3
We calculate the equation of state of isospin-symmetric nuclear matter in the three-loop approximation of chiral perturbation theory. The contributions to the energy per particle $\bar E(k_f)$ from one- and two-pion exchange diagrams are ordered in powers of the Fermi momentum $k_f$ (modulo functions of $k_f /m_\pi$). It is demonstrated that, already at order ${\cal O}(k_f^4)$, two-pion exchange produces realistic nuclear binding. The underlying saturation mechanism is surprisingly simple (in the chiral limit), namely the combination of an attractive $k_f^3$-term and a repulsive $k_f^4$-term. The empirical saturation point and the nuclear compressibility $K\simeq 250 $MeV are well reproduced at order ${\cal O}(k_f^5)$ with a momentum cut-off of $\Lambda \simeq 0.65$ GeV which parametrizes short-range dynamics. No further short-distance terms are required in our calculation of nuclear matter. In the same framework we calculate the density-dependent asymmetry energy and find $A_0\simeq 34 $MeV at the saturation point, in good agreement with the empirical value. The pure neutron matter equation of state is also in fair qualitative agreement with sophisticated many-body calculations and a resummation result of effective field theory, but only for low neutron densities $\rho_n <0.25 $fm$^{-3}$.
Fritsch S.
Kaiser Nicholas
Weise Wolfram
No associations
LandOfFree
Chiral Dynamics and Nuclear Matter does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Chiral Dynamics and Nuclear Matter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Chiral Dynamics and Nuclear Matter will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-354216