Quark matter in neutron stars

According to quantum chromodynamics, matter at ultra-high density and low temperature is a quark liquid, with a condensate of Cooper pairs of quarks near the Fermi surface ("color superconductivity"). This paper reviews the physics of color superconductivity, and discusses some of the proposed signatures by which we might detect quark matter in neutron stars.Comment: 8 pages, 3 figures; To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennessee. v2: typo corrected, line numbers remove

Color-Flavor Locking and Chiral Symmetry Breaking in High Density QCD

We propose a symmetry breaking scheme for QCD with three massless quarks at high baryon density wherein the color and flavor SU(3)_color times SU(3)_L times SU(3)_R symmetries are broken down to the diagonal subgroup SU(3)_{color+L+R} by the formation of a condensate of quark Cooper pairs. We discuss general properties that follow from this hypothesis, including the existence of gaps for quark and gluon excitations, the existence of Nambu-Goldstone bosons which are excitations of the diquark condensate, and the existence of a modified electromagnetic gauge interaction which is unbroken and which assigns integral charge to the elementary excitations. We present mean-field results for a Hamiltonian in which the interaction between quarks is modelled by that induced by single-gluon exchange. We find gaps of order 10-100 MeV for plausible values of the coupling. We discuss the effects of nonzero temperature, nonzero quark masses and instanton-induced interactions on our results.Comment: 17 pages, LaTeX. Factors of 2 corrected, figs and tables updated accordingl

Neutral color-spin locking phase in neutron stars

We present results for the spin-1 color-spin locking phase (CSL) using a NJL-type model in two flavor quark matter for compact stars applications. The CSL condensate is flavor symmetric and therefore charge and color neutrality can easily be satisfied. We find small energy gaps ~1 MeV, which make the CSL matter composition and the EoS not very different from the normal quark matter phase. We keep finite quark masses in our calculations and obtain no gapless modes that could have strong consequences in the late cooling of neutron stars. Finally, we show that the region of the phase diagram relevant for neutron star cores, when asymmetric flavor pairing is suppressed, could be covered by the CSL phase.Comment: 3 pages, 4 figures, contribution talk to the IVth International Conference on Quarks and Nuclear Physics(QNP06), Madrid, Spain, 5-10 Jun 200

Mixed phases of color superconducting quark matter

We examine electrically and color neutral quark matter in beta-equilibrium focusing on the possibility of mixed phases between different color superconducting phases. To that end we apply the Gibbs criterion to ensure phase equilibrium and discuss the external conditions under which these mixed phases can occur. Neglecting surface and Coulomb effects we find a rich structure of different mixed phases with up to four components, including 2SC and CFL matter as well as more ``exotic'' components, like a phase with us- and ds-pairing but without ud-pairing. Preliminary estimates indicate, however, that the mixed phases become unstable if surface and Coulomb effects are included.Comment: 22 pages, 9 figures, v2: minor changes in the text, version to appear in Nucl. Phys.

Critical Literacy and Second Language Learning in the Mainstream Classroom: An Elusive Nexus?

Critical Literacy (CL) is now a core component of Queensland secondary school English programs. These programs are delivered to a significant number of students from Non-English speaking backgrounds (NESB) whose linguistic and cultural resources are diverse and not necessarily representative of mainstream high school cultural capital (Bourdieu 1990). In response to the current emphasis on CL, it is vital for English as a Second Language (ESL) educators to identify the points of contention as well as the possibilities for promoting critical engagement with texts with adolescent ESL learners and to seek to create pedagogy that reflects the critical needs and capacities of these learners. This paper outlines the version of CL in secondary schools as theorised by a number of Australian researchers; discusses the relevance and importance of CL to NESB learners and finally raises a number of issues that need resolving if such learners are to be provided with a well-rounded literacy education amid contemporary Australian social relations and textual practice

Gapless two-flavor color superconductor

A new, gapless two-flavor color superconducting phase that appears under conditions of local charge neutrality and $\beta$-equilibrium is revealed. In this phase, the symmetry of the ground state is the same as in the conventional two-flavor color superconductor. In the low-energy spectrum of this phase, however, there are only two gapped fermionic quasiparticles, and the other four quasiparticles are gapless. The origin and the basic properties of the gapless two-flavor color superconductor are discussed. This phase is a natural candidate for quark matter in cores of compact stars.Comment: 6 pages, 4 figures. 1 reference and 1 figure are added; the discussion of the effective potential properties is extende

E-Business Models In The Travel Industry

Drawing on recently published data, this report examines some of the trends in travel e-commerce. Using a case study approach, the author examines in detail some of the e-business models impacting on the travel industry both in the Business-to-Business (B2B) and Business-to-Consumer (B2C) markets. Although B2C leisure transactions currently account for just 1% of the value of global travel, there is real potential for future growth. However to be successful both new entrants and existing players will need to ensure their e-business model adds value for the customer, otherwise their position in the value chain will be threatened. The most immediate potential for growth and profitability lies in the B2B market, particularly in the development of vertical portals or community extranets. These are virtual spaces enabling travel buyers and suppliers to trade online. The integration of legacy systems with Internet Protocol (IP) technology is taking place across a range of travel sectors and will provide the platform on which a wide range of e-business applications can be developed. This development will lead to the ultimate catalyst for travel e-business -- the convergence of data (internet), voice (telephone) and video (television)

eCRM in the Travel Industry

We are bombarded with Internet forecasts and statistics every day, however there is little doubt that the Internet has permanently changed the face of travel promotion and distribution. While only a minority of consumers are actually prepared to buy online at the present time, this minority is growing and there are large numbers of consumers who wish to use the Internet for information and communication. Travel and hospitality companies are selling an information-rich product and will need to leverage the full range of offline and e-channels to engage their customers in dialogue. The Internet does not have any respect for geographic or organisational boundaries and companies will have to forge new business models, involving partnerships and customer-driven product design, in order to meet the needs of the online consumer. There are major challenges and opportunities for companies wishing to add the e to their CRM strategy

Quenched Hadron Spectroscopy with Improved Actions

A variety of different combinations of improved gluon and fermion actions is tested for quenched hadron spectroscopyComment: 3 pages, latex, 4 figures, talk presented at the LATTICE9