Bulletin of the American Physical Society
2005 2nd Joint Meeting of the Nuclear Physics Divisions of the APS and The Physical Society of Japan
Sunday–Thursday, September 18–22, 2005; Maui, Hawaii
Session CB: Mini-symposium on Chiral and Color Condensation I |
Hide Abstracts |
Sponsoring Units: DNP JPS Chair: Satoru Hirenzaki, Nara Women's University Room: Ritz-Carlton Hotel Salon 3 |
Tuesday, September 20, 2005 2:00PM - 2:30PM |
CB.00001: The Structure of Hadronic Matter from Nuclei to Neutron Stars Invited Speaker: In recent years it has become apparent that the intermediate scalar attraction in the NN system should lead to some modification of the internal structure of the nucleon. At the simplest level this effect corresponds to a non-zero scalar polarizability which, in most models investigated so far, tends to oppose the applied scalar field. Such a mechanism naturally leads to saturation of nuclear matter. We shall review the key results of the QMC model and later covariant versions, with a special emphasis on the possibility of testing such ideas experimentally - especially at Jefferson Laboratory. Key examples include modifications of the structure functions and form factors of bound ``nucleons'' as well as the predictions for hypernuclei. We also discuss the application of such models to dense nuclear matter, including possible phase transitions to quark matter or superconducting quark matter. [Preview Abstract] |
Tuesday, September 20, 2005 2:30PM - 2:45PM |
CB.00002: Phase Diagram of Quark Matter at Finite Temperature and Density in the Strong Coupling Limit Lattice QCD with $N_c = 3$ Akira Ohnishi, Noboru Kawamoto, Kotaro Miura, Toshihiko Ohnuma Exploring various phases of quark and nuclear matter has recently attracted much attention both from theoretical and experimental sides. For cold baryon rich matter, the first principle lattice QCD simulation is not yet available then it is necessary to invoke some approximations in QCD or to apply some effective theories. We study here nuclear matter at finite temperature and density in the strong coupling limit (SCL) lattice QCD. It is already shown that SCL can describe chiral phase transition at finite temperature$^1$. At finite densities, we may have diquark condensate, which has color and cannot be an order parameter as it is in lattice QCD. Because of this difficulty, studies are limited to $N_c=2$ case$^2$ or zero temperature$^3$. We have recently developed a way to extract the color singlet combination from diquark condensates. In the presentation, we explain how we can define and extract color singlet order parameter, and discuss color and chiral condensates in dense matter. \\[0.5ex] 1. P.~H.~Damgaard, N.~Kawamoto, K.~Shigemoto, Phys. Rev. Lett. {\bf 53},2211(1984). \\ 2. Y. Nishida et al., Phys. Rept. {\bf 394}, 281 (2004). \\ 3. V. Azcoiti et al., JHEP {\bf 0309}, 014 (2003). [Preview Abstract] |
Tuesday, September 20, 2005 2:45PM - 3:00PM |
CB.00003: The effects of thermal fluctuations of gauge fields in realistic dense quark matter Taeko Matsuura, Kei Iida, Motoi Tachibana, Tetsuo Hatsuda We investigate a high density phase structure of color superconducting quark matter near the boundary with a normal phase using the Ginzburg-Landau free energy. For realistic description, in addition to the effects of nonzero strange quark mass and electric charge neutrality, we take into account the effect of thermal fluctuations of gluons. We show how the gluon fluctuations change the high density phase structure near the boundary from the three successive second-order phase transitions, a modified color-flavor locked phase (ud, ds, and us pairings) $\rightarrow$ a ``dSC'' phase (ud and ds pairings) $\rightarrow$ an isoscalar pairing phase (ud pairing) $\rightarrow$ a normal phase (no pairing), obtained from mean-field calculations. [Preview Abstract] |
Tuesday, September 20, 2005 3:00PM - 3:15PM |
CB.00004: Collective excitations in a superfluid of color-flavor locked quark matter Kenji Fukushima, Kei Iida By using the Nambu-Jona-Lasinio (NJL) model in the mean-field approximation, we derive the spectra both for the normal and color-flavor locked (CFL) superfluid phases at zero and finite temperature. In the normal phase, we obtain zero sound as a low-lying collective mode in the particle-hole (vector) channel. In the CFL phase, when the excitation energy, $\omega$, is smaller than the threshold given by twice the pairing gap $\Delta$ ($\omega<2\Delta$), a phonon corresponding to fluctuations in the U(1) phase of $\Delta$ appears as a sharp peak in the particle-particle ($H$) channel. The excitation energy goes up and asymptotically approaches $\omega=2\Delta$ with increasing momentum of the phonon. Above the threshold for pair excitations ($\omega>2\Delta$), zero sound manifests itself in the vector channel. We also find that in the long wavelength limit the phonon mode has its spectral weight in the $H$ channel alone, while the spectral function vanishes in the vector channel. [Preview Abstract] |
Tuesday, September 20, 2005 3:15PM - 3:30PM |
CB.00005: Feedback effects on the pairing interaction in color superconductors near the transition temperature Kei Iida We examine the role that the gap dependence of the pairing interaction plays in the gap equation for a weakly coupled uniform superfluid of three-flavor massless quarks near the transition temperature $T_c$. We find that the feedback effects on Landau-damped transverse gluons mediating the pairing interaction alter the gap magnitude in a way dependent on the color structure of the gap. We estimate corrections by these effects to the parameters characterizing the fourth-order terms in the Ginzburg-Landau free energy and ensure the stability of a color-flavor locked state near $T_c$. [Preview Abstract] |
Tuesday, September 20, 2005 3:30PM - 3:45PM |
CB.00006: Color Ferromagnetism and Color Superconductivity in Dense Quark Matter Aiichi Iwazaki, Osamu Morimatsu, Tetsuo Nishikawa, Munehisa Ohtani As we have shown, Savvidy vacuum unstable in vacuum becomes stable in dense quark matter, so that a color magnetic field is generated spontaneously. We compare the free energy of this color ferromagnetic state with the free energies of color superconducting states ( CFL and 2SC ) of dense quark matter. We find that the color ferromagnetic state is more stable than the color superconducting states in an range of baryon chemical potentials accessible in experiments or neutron stars. Although the strength of the color magnetic field is not known, the result holds for a wide range of the magnetic field strength. [Preview Abstract] |
Tuesday, September 20, 2005 3:45PM - 4:00PM |
CB.00007: Vortex excitation and quark spectrum in color ferromagnetic state in cold dense matter Munehisa Ohtani, Aiichi Iwazaki, Osamu Morimatsu, Tetsuo Nishikawa We show a possibility that there exists a color ferromagnetic state in quark matter, in which a color magnetic field is spontaneously generated. The state arises between the hadronic state and the color superconducting state when the density of quarks is varied. We find a vortex solution in the color ferromagnetic state as an analogue of a quasi-particle in the quantum Hall state. We analyze the vortex excitation energy and quark spectrum to discuss the stability of the color ferromagnetic state in comparison with the color superconducting phase. [Preview Abstract] |
Tuesday, September 20, 2005 4:00PM - 4:15PM |
CB.00008: Quark spectrum in QGP near chiral transition Yukio Nemoto, Masakiyo Kitazawa, Teiji Kunihiro Near but the critical temperature $T_C$ of the chiral transition, a collective excitation due to the fluctuation of the chiral condensate, called a soft mode, appears. We investigate how the soft mode affects the quark properties. The spectral function of a quark shows a several-peak structure at low frequency and momentum. We show that one of the peaks is the plasmino state and the spectral structure is understood in terms of resonant scatterings of a quark off the soft mode. The quasiquark and the plasmino have thermal masses near $T_C$, which results from the level repulsions between a quark and an antihole and between an antiquark and a hole. Effects of finite density are also presented. [Preview Abstract] |
Tuesday, September 20, 2005 4:15PM - 4:30PM |
CB.00009: Renormalization group fixed points and chiral restoration scenarios from generalized hidden local symmetry approach Yoshimasa Hidaka, Osamu Morimatsu, Munehisa Ohtani There are some proposals for realization patterns of chiral symmetry. In the standard scenario of chiral symmetry, the chiral partner of the pion is the sigma meson. Another scenario, Vector Manifestation (VM), has been recently proposed, in which the chiral partner of the pion is the rho meson. We study these chiral restoration patterns from renormalization group approach in the generalized hidden local symmetry(GHLS) model, which includes vector and axial-vector mesons in addition to pions as physical degrees of freedom. We found two types of fixed points corresponding to the standard and VM scenarios. The decay-constant ratio of rho meson to $A_1$ becomes unit ($F_{\rho}/F_{A_1}=1$) in the standard scenario, while in the VM scenario that of pion becomes unit ($F_{\rho}/F_{\pi}=1$) on the fixed point. We discuss the possibilities of the realization in these scenarios. [Preview Abstract] |
Tuesday, September 20, 2005 4:30PM - 4:45PM |
CB.00010: Condensates in Lattice Landau Gauge QCD Sadataka Furui, Hideo Nakajima The running coupling and the Kugo-Ojima parameter c of unquenched lattice Landau gauge are measured and compared with the continuum theory. We used gauge configurations of JLQCD/CP- PACS with Wilson fermion and those of Columbia University and MILC with Kogut-Susskind fermions. Although there exists dependence on the polarization due to asymmetry of the lattice, it is observed that c is consistent with 1. Presence of infrared fixed point of $\alpha_0\sim 2-2.5$ irrespective of the fermion actions in the continuum and in the chiral limit is suggested. In comparison with pQCD results in $\widetilde{MOM}$ scheme up to the 4-loop level, the MILC data of $\alpha_s$ in the region $1\sim 3$GeV exhibit presence of dimension 2 condensates and dimension 4 condensates with sign opposite to the dimension 2 condensates. We observed that Zwanziger’s horizon condition is satisfied within errors. The dimension 2 condensates is interpreted as the square norm of the gauge field which is related to the Zwanziger's horizon condition and the dimension 4 condensates is interpreted as the quark condensates. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700