摘要We investigate nucleon mass splitting at finite isospin chemical potential in the frame of the two-flavour Nambu--Jona-Lasinio model. It is analytically proven that in the phase with explicit isospin symmetry breaking, the proton mass decreases and the neutron mass increases linearly in the isospin chemical potential.
Abstract：We investigate nucleon mass splitting at finite isospin chemical potential in the frame of the two-flavour Nambu--Jona-Lasinio model. It is analytically proven that in the phase with explicit isospin symmetry breaking, the proton mass decreases and the neutron mass increases linearly in the isospin chemical potential.
[1] Son D T and Stephanov M A 2001 Phys. Rev. Lett. 86 592 Son D T and Stephanov M A 2001 Phys. Atom. Nucl. 64 834 [2] Kogut J B and Sinclair D K 2002 Phys. Rev. D 66 034505 Son D T and Stephanov M A 2002 Phys. Rev. D 66 014508 Son D T and Stephanov M A 2004 Phys. Rev. D 70 094501 [3] Kogut J B and Toublan D 2001 Phys. Rev. D 64 034007 [4] Splittorff K, Son D T and Stephanov M A 2001 Phys.Rev. D 64 016003 [5] Loewe M and Villavicencio C 2003 Phys. Rev. D 67 074034 Loewe M and Villavicencio C 2004 Phys. Rev. D 70 074005 [6] Birse M C, Cohen T D and McGovern J A 2001 Phys. Lett.B 516 27 [7] Toublan D and Kogut J B 2003 Phys. Lett. B 564 212 [8] Barducci A, Casalbuoni R, Pettini G and Ravagli L 2004 Phys.Rev. D 69 096004 Barducci A, Casalbuoni R, Pettini G and Ravagli L 2005 Phys.Rev. D 71 016011 [9] Frank M, Buballa M and Oertel M 2003 Phys. Lett. B 562 221 [10] He L Y, Jin M and Zhuang P F 2005 Phys. Rev. D 71 116001 [11] Klein B, Toublan D and Verbaarschot J J M Preprinthep-ph/0405180 Klein B, Toublan D and Verbaarschot J J M 2003 Phys. Rev. D 68 014009 [12] Barducci A, Casalbuoni R, Pettini G and Ravagli L 2003 Phys. Lett. B 564 217 [13] Nishida Y 2004 Phys. Rev. D 69 094501 [14] Ishii N, Bentz W and Yazaki K 1993 Phys. Lett. B 301 165 Ishii N, Bentz W and Yazaki K 1993 Phys. Lett. B 318 26 [15] Klevansky S P 1992 Rev. Mod. Phys. 64 649 [16] Zhuang P F Preprint hep-ph/0503250 [17] Buck A, Alkofer R and Reinhardt H 1993 Phys. Lett. B 286 29 [18] Mineo H, Bentz W and Yazaki K 1999 Phys. Rev. C 60 065201
2008, Vol. 25 
