1,455 research outputs found
Psychological Wellbeing of Polish Migrants: What is the Role of the NHS?
Aim: Polish migrants are currently the largest immigrant population in the UK. This study aimed to explore what the NHS is currently doing for this population and what needs to change for the services to be more accessible to Polish migrants.
Method: Freedom of Information Act Requests (FOIRs) were sent to all 56 Mental Health Trusts to investigate whether the NHS is serving Polish migrants by monitoring access to services. An online survey of Polish migrants was used to address the research question “What might need to change in order to make mental health services accessible/used by Polish migrants in the UK?”. The survey participants were recruited online through Facebook groups and online Polish news media. Data was analysed using descriptive and inferential statistics.
Results: Forty six Trusts responded to the FOIRs. The results indicate that very few Trusts collect information on access to services by Polish migrants. No Trust reported having developed a race equality strategy that attempts to address the needs of Polish service users specifically. Six hundred and five Polish people completed the online survey. The majority of participants (76.5%) identified as female and the average age was 35. The results indicate that a high proportion of Polish migrants are likely to experience mental health difficulties. Identified causal factors included work stress, isolation and loneliness, family stress, relationship problems and migration. The current study found that out of the 369 participants who reported mental health problems 40.9% sought support for their difficulties through the NHS. Participants who sought help had, on average, lived longer in the UK (p = 0.001). Barriers to accessing help included language difficulties, lack of time, lack of belief in services and experiences of fear and shame. Self-help strategies and family support were listed as protective factors.
Recommendations: In line with developing culturally competent services the NHS should adopt a practical approach to engaging this community and focus on enhancing the relationship between Polish migrants and the GP, adopt community approaches and pay attention to the identified causal beliefs of distress which centre around psycho-social factors such as stressful work conditions and isolation
Early anisotropic hydrodynamics and the RHIC early-thermalization and HBT puzzles
We address the problem if the early thermalization and HBT puzzles in
relativistic heavy-ion collisions may be solved by the assumption that the
early dynamics of the produced matter is locally anisotropic. The hybrid model
describing the purely transverse hydrodynamic evolution followed by the
perfect-fluid hydrodynamic stage is constructed. The transition from the
transverse to perfect-fluid hydrodynamics is described by the Landau matching
conditions applied at a fixed proper time. The global fit to the RHIC data
reproduces the soft hadronic observables (the pion, kaon, and the proton
spectra, the pion and kaon elliptic flow, and the pion HBT radii) with the
accuracy of about 20%. These results indicate that the assumption of the very
fast thermalization may be relaxed. In addition, the presented model suggests
that a large part of the inconsistencies between the theoretical and
experimental HBT results may be removed.Comment: replaced with the version published in Phys.Rev.C 8
Viscosity of an ideal relativistic quantum fluid: A perturbative study
We show that a quantized ideal fluid will generally exhibit a small but
non-zero viscosity due to the backreaction of quantum soundwaves on the
background. We use an effective field theory expansion to estimate this
viscosity to first order in perturbation theory. We discuss our results, and
whether this estimate can be used to obtain a more model-independent estimate
of the "quantum bound" on the viscosity of physical systemsComment: Accepted for publication, Phys.Rev.D. Discussion slightly clarified
and extended, references added, error in calculation fixed. COnclusions
unchange
Size fluctuations of the initial source and the event-by-event transverse momentum fluctuations in relativistic heavy-ion collisions
We show that the event-by-event fluctuations of the transverse size of the
initial source, which follow directly from the Glauber treatment of the
earliest stage of relativistic heavy-ion collisions, cause, after hydrodynamic
evolution, fluctuations of the transverse flow velocity at hadronic freeze-out.
This in turn leads to event-by-event fluctuations of the average transverse
momentum, p_T. Simulations with GLISSANDO for the Glauber phase, followed by a
realistic hydrodynamic evolution and statistical hadronization carried out with
THERMINATOR, lead to agreement with the RHIC data. In particular, the magnitude
of the effect, its centrality dependence, and the weak dependence on the
incident energy are properly reproduced. Our results show that bulk of the
observed event-by-event p_T fluctuations may be explained by the fluctuations
of the size of the initial source.Comment: 5 pages, 4 figures, version accepted in PR
The Hagedorn temperature Revisited
The Hagedorn temperature, T_H is determined from the number of hadronic
resonances including all mesons and baryons. This leads to a stable result T_H
= 174 MeV consistent with the critical and the chemical freeze-out temperatures
at zero chemical potential. We use this result to calculate the speed of sound
and other thermodynamic quantities in the resonance hadron gas model for a wide
range of baryon chemical potentials following the chemical freeze-out curve. We
compare some of our results to those obtained previously in other papers.Comment: 13 pages, 4 figure
A Hybrid Model for QCD Deconfining Phase Boundary
Intensive search for a proper and realistic equations of state (EOS) is still
continued for studying the phase diagram existing between quark gluon plasma
(QGP) and hadron gas (HG) phases. Lattice calculations provide such EOS for the
strongly interacting matter at finite temperature () and vanishing baryon
chemical potential (). These calculations are of limited use at finite
due to the appearance of notorious sign problem. In the recent past,
we had constructed a hybrid model description for the QGP as well as HG phases
where we make use of a new excluded-volume model for HG and a
thermodynamically-consistent quasiparticle model for the QGP phase and used
them further to get QCD phase boundary and a critical point. Since then many
lattice calculations have appeared showing various thermal and transport
properties of QCD matter at finite and . We test our hybrid
model by reproducing the entire data for strongly interacting matter and
predict our results at finite so that they can be tested in future.
Finally we demonstrate the utility of the model in fixing the precise location,
the order of the phase transition and the nature of CP existing on the QCD
phase diagram. We thus emphasize the suitability of the hybrid model as
formulated here in providing a realistic EOS for the strongly interacting
matter.Comment: 22 pages, 10 figures. corrected version published in Physical Review
D. arXiv admin note: substantial text overlap with arXiv:1201.044
Temperature dependent sound velocity in hydrodynamic equations for relativistic heavy-ion collisions
We analyze the effects of different forms of the sound-velocity function
cs(T) on the hydrodynamic evolution of matter formed in the central region of
relativistic heavy-ion collisions. At high temperatures (above the critical
temperature Tc) the sound velocity is calculated from the recent lattice
simulations of QCD, while in the low temperature region it is obtained from the
hadron gas model. In the intermediate region we use different interpolations
characterized by the values of the sound velocity at the local maximum (at T =
0.4 Tc) and local minimum (at T = Tc). In all considered cases the temperature
dependent sound velocity functions yield the entropy density, which is
consistent with the lattice QCD simulations at high temperature. Our
calculations show that the presence of a distinct minimum of the sound velocity
leads to a very long (about 20 fm/c) evolution time of the system, which is not
compatible with the recent estimates based on the HBT interferometry. Hence, we
conclude that the hydrodynamic description is favored in the case where the
cross-over phase transition renders the smooth sound velocity function with a
possible shallow minimum at Tc.Comment: 6 pages, 3 figures, talk given at SQM'07 Levoca, Slovaki
Solution of the RHIC HBT puzzle with Gaussian initial conditions
It is argued that the consistent description of the transverse-momentum
spectra, elliptic flow, and the HBT radii in the relativistic heavy-ion
collisions studied at RHIC may be obtained within the hydrodynamic model if one
uses the Gaussian profile for the initial energy density in the transverse
plane. Moreover, we show that the results obtained in the scenario with an
early start of hydrodynamics (at the proper time tau0 = 0.25 fm) are
practically equivalent to the results obtained in the model where the
hydrodynamics is preceded by the free-streaming stage of partons (in the proper
time interval 0.25 fm < tau < 1 fm) which suddenly equilibrate and with the
help of the Landau matching conditions are transformed into the hydrodynamic
regime (at the proper time tau0 = 1 fm).Comment: talk presented by WF at SQM2008 Conferenc
Free-streaming approximation in early dynamics of relativistic heavy-ion collisions
We investigate an approximation to early dynamics in relativistic heavy-ion
collisions, where after formation the partons are free streaming and around the
proper time of 1 fm/c undergo a sudden equilibration described in terms of the
Landau matching condition. We discuss physical and formal aspects of this
approach. In particular, we show that initial azimuthally asymmetric transverse
flow develops for non-central collisions as a consequence of the sudden
equilibration. Moreover, the energy-momentum tensor from the free-streaming
stage matches very smoothly to the form used in the transverse hydrodynamics,
whereas matching to isotropic hydrodynamics requires a more pronounced change
in the energy-momentum tensor. After the hydrodynamic phase statistical
hadronization is carried out with the help of THERMINATOR. The physical results
for the transverse-momentum spectra, the elliptic-flow, and the
Hanbury-Brown--Twiss correlation radii, including the ratio R_out/R_side as
well as the dependence of the radii on the azimuthal angle (azHBT), are
properly described within our approach. The agreement is equally good for a
purely hydrodynamic evolution started at an early proper time of 0.25 fm/c, or
for the free streaming started at that time, followed by the sudden
equilibration at tau ~1 fm/c and then by perfect hydrodynamics. Thus, the
inclusion of free streaming allows us to delay the start of hydrodynamics to
more realistic times of the order of 1 fm/c.Comment: 10 pages, 12 figure
Dissipative hydrodynamics coupled to chiral fields
Using second--order dissipative hydrodynamics coupled self-consistently to
the linear model we study the 2+1 dimensional evolution of the
fireball created in Au+Au relativistic collisions. We analyze the influence of
the dynamics of the chiral fields on the charged-hadron elliptic flow and
on the ratio for a temperature-independent as well as for a
temperature-dependent viscosity-to-entropy ratio calculated from the
linearized Boltzmann equation in the relaxation time approximation. We find
that is not very sensitive to the coupling of chiral sources to the
hydrodynamic evolution, but the temperature dependence of plays a much
bigger role on this observable. On the other hand, the ratio
turns out to be much more sensitive than to both the coupling of the
chiral sources and the temperature dependence of .Comment: 12 two-column pages, 9 figures. v2: minor changes, matches published
article in Phys. Rev.
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