7,180 research outputs found
Locating the critical end point using the linear sigma model coupled to quarks
We use the linear sigma model coupled to quarks to compute the effective
potential beyond the mean field approximation, including the contribution of
the ring diagrams at finite temperature and baryon density. We determine the
model couplings and use them to study the phase diagram in the baryon chemical
potential-temperature plane and to locate the Critical End Point.Comment: 8 pages, 2 figures, conference paper from ISMD 201
Shadowing of gluons in perturbative QCD: A comparison of different models
We investigate the different perturbative QCD-based models for nuclear
shadowing of gluons. We show that in the kinematic region appropriate to RHIC
experiment, all models give similar estimates for the magnitude of gluon
shadowing. At scales relevant to LHC, there is a sizable difference between
predictions of the different models.Comment: 11 pages, 4 figure
Boundary and expansion effects on two-pion correlation functions in relativistic heavy-ion collisions
We examine the effects that a confining boundary together with hydrodynamical
expansion play on two-pion distributions in relativistic heavy-ion collisions.
We show that the effects arise from the introduction of further correlations
due both to collective motion and the system's finite size. As is well known,
the former leads to a reduction in the apparent source radius with increasing
average pair momentum K. However, for small K, the presence of the boundary
leads to a decrease of the apparent source radius with decreasing K. These two
competing effects produce a maximum for the effective source radius as a
function of K.Comment: 6 pages, 5 Eps figures, uses RevTeX and epsfi
Nuclear shadowing from exclusive quarkonium photoproduction at the BNL RHIC and CERN LHC
The photonuclear production of vector mesons in ultraperipheral heavy ion
collisions is investigated within the collinear approach using different
parameterizations for the nuclear gluon distribution. The integrated cross
section and the rapidity distribution for the () process are computed for energies of RHIC and LHC. A comparison with
the recent PHENIX data on coherent production of mesons is also
presented. We demonstrate that the study of the exclusive quarkonium
photoproduction can be used to constrain the nuclear effects in the gluon
distribution.Comment: 8 pages, 4 figures, 2 tables. Version to be published in Physical
Review
The Wilson renormalization group for low x physics: towards the high density regime
We continue the study of the effective action for low physics based on a
Wilson renormalization group approach. We express the full nonlinear
renormalization group equation in terms of the average value and the average
fluctuation of extra color charge density generated by integrating out gluons
with intermediate values of . This form clearly exhibits the nature of the
phenomena driving the evolution and should serve as the basis of the analysis
of saturation effects at high gluon density at small .Comment: 14 pages, late
Density and expansion effects on pion spectra in relativistic heavy-ion collisions
We compute the pion inclusive momentum distribution in heavy-ion collisions
at AGS energies, assuming thermal equilibrium and accounting for density and
expansion effects at the time of decoupling. We compare to data on mid rapidity
charged pions produced in central Au + Au collisions and find a very good
agreement. The shape of the distribution at low is explained in part as
an effect arising from the high mean pion density achieved in these reactions.
The difference between the positive and negative pion distributions in the same
region is attributed in part to the different average yields of each kind of
charged pions.Comment: Minor changes, typo in Fig. 2b corrected, version to appear in Phys.
Rev.
Recommended from our members
Recommendations for Implementing Hepatitis C Virus Care in Homeless Shelters: The Stakeholder Perspective.
Compared with the general population, homeless individuals are at higher risk of hepatitis C infection (HCV) and may face unique barriers in receipt of HCV care. This study sought the perspectives of key stakeholders toward establishing a universal HCV screening, testing, and treatment protocol for individuals accessing homeless shelters. Four focus groups were conducted with homeless shelter staff, practice providers, and social service outreach workers (n = 27) in San Francisco, California, and Minneapolis, Minnesota. Focus groups evaluated key societal, system, and individual-level facilitators and barriers to HCV testing and management. Interviews were transcribed and analyzed thematically. The societal-level barriers identified were lack of insurance, high-out-of-pocket expenses, restriction of access to HCV treatment due to active drug and/or alcohol use, and excessive paperwork required for HCV treatment authorization from payers. System-level barriers included workforce constraints and limited health care infrastructure, HCV stigma, low knowledge of HCV treatment, and existing shelter policies. At the individual level, client barriers included competing priorities, behavioral health concerns, and health attitudes. Facilitators at the system level for HCV care service integration in the shelter setting included high acceptability and buy in, and linkage with social service providers. Conclusion: Despite societal, system, and individual-level barriers identified with respect to the scale-up of HCV services in homeless shelters, there was broad support from key stakeholders for increasing capacity for the provision of HCV services in shelter settings. Recommendations for the scale-up of HCV services in homeless shelter settings are discussed
- …