Energy loss in a fluctuating hydrodynamical background

Recently it has become apparent that event-by-event fluctuations in the initial state of hydrodynamical modelling of ultrarelativistic heavy-ion collisions are crucial in order to understand the full centrality dependence of the elliptic flow coefficient v_2. In particular, in central collisions the density fluctuations play a major role in generating the spatial eccentricity in the initial state. This raises the question to what degree high P_T physics, in particular leading-parton energy loss, which takes place in the background of an evolving medium, is sensitive to the presence of the event-by-event density fluctuations in the background. In this work, we report results for the effects of fluctuations on the nuclear modification factor R_AA in both central and noncentral sqrt(s_NN) = 200 GeV Au+Au collisions at RHIC. Two different types of energy-loss models, a radiative and an elastic, are considered. In particular, we study the dependence of the results on the assumed spatial size of the density fluctuations, and discuss the angular modulation of R_AA with respect to the event plane.Comment: 9 pages, 9 figure

Elastic energy loss with respect to the reaction plane in a Monte-Carlo model

We present a computation of $\pi^0$ nuclear modification factor with respect to the reaction plane in Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV, based on a Monte-Carlo model of elastic energy loss of hard partons traversing the bulk hydrodynamical medium created in ultrarelativistic heavy-ion collisions. We find the incoherent nature of elastic energy loss incompatible with the measured data.Comment: 5 pages, 2 figure

Systematics of parton-medium interaction from RHIC to LHC

Despite a wealth of experimental data for high-P_T processes in heavy-ion collisions, discriminating between different models of hard parton-medium interactions has been difficult. A key reason is that the pQCD parton spectrum at RHIC is falling so steeply that distinguishing even a moderate shift in parton energy from complete parton absorption is essentially impossible. In essence, energy loss models are effectively only probed in the vicinity of zero energy loss and, as a result, at RHIC energies only the pathlength dependence of energy loss offers some discriminating power. At LHC however, this is no longer the case: Due to the much flatter shape of the parton p_T spectra originating from 2.76 AGeV collisions, the available data probe much deeper into the model dynamics. A simultaneous fit of the nuclear suppression at both RHIC and LHC energies thus has great potential for discriminating between various models that yield equally good descriptions of RHIC data alone.Comment: Talk given at Quark Matter 2011, 22-28 May 2011, Annecy, Franc

THE CONSTRUCTION DATE OF THE DOMINICAN CONVENT OF ST OLAF IN TURKU, FINLAND: A RE-EVALUATION

The foundation of the medieval Dominican Convent of St Olaf in Turku, South-West Finland, marked the connection of the country to an international network of contacts with the Latin West, and the establishment of taught education in Finland. However, the chronology of its construction has been a subject of scholarly debate since the early 20th century. The archaeological material from the convent is scant, and the only properly datable finds are a sample of timber from the structures and a collection of bricks recovered from the site. In this article we present the results of a wiggle-match dating of the timber, and OSL dating of eight bricks. The bricks were also analysed by pXRF. The building phase of brick masonry seems to date to the second half of the 14th century or around 1400AD

Temperature dependence of eta/s of strongly interacting matter : Effects of the equation of state and the parametric form of (eta/s)(T)

We investigate the temperature dependence of the shear viscosity to entropy density ratio eta/s using a piecewise linear parametrization. To determine the optimal values of the parameters and the associated uncertainties, we perform a global Bayesian model-to-data comparison on Au + Au collisions at root s(NN) = 200 GeV and Pb + Pb collisions at 2.76 TeV and 5.02 TeV, using a 2 + 1D hydrodynamical model with the Eskola-KajantieRuuskanen-Tuominen (EKRT) initial state. We provide three new parametrizations of the equation of state (EoS) based on contemporary lattice results and hadron resonance gas, and use them and the widely used s95p parametrization to explore the uncertainty in the analysis due to the choice of the equation of state. We find that eta/s is most constrained in the temperature range T approximate to 150-220 MeV, where, for all EoSs, 0.08 <eta/s <0.23 when taking into account the 90% credible intervals. In this temperature range the EoS parametrization has only a small similar to 10% effect on the favored eta/s value, which is less than the similar to 30% uncertainty of the analysis using a single EoS parametrization. Our parametrization of (eta/s)(T) leads to a slightly larger minimum value of eta/s than the previously used parametrizations. When we constrain our parametrization to mimic the previously used parametrizations, our favored value is reduced, and the difference becomes statistically insignificant.Peer reviewe

Incidence of stroke and mortality due to stroke after acute coronary syndrome

Objectives: Stroke is a known complication after myocardial infarction (MI) and it is associated with increased mortality. We aimed to establish the true cumulative incidence of stroke and its subtypes and the associated mortality in a contemporary setting among patients treated for acute coronary syndrome (ACS). Materials and methods: A retrospective registry study based on the data of 8,049 consecutive patients treated for ACS in a sole provider of specialized cardiac and neurologic care for a catchment area of over 0.5 million residents between 2007 and 2018. Incident strokes and their subtypes were identified by in-depth review of written hospital records, hospital discharge registry data and causes of death registry data maintained by Statistics Finland up until December 31st 2020. Results: During a median follow-up of 5.8 years (IQR 3.2-9.0) 570 ACS patients suffered a stroke. The cumulative incidences of stroke for first week, first month, first year and at thirteen years were: 0.8 %, 1.1 %, 2.2 % and 10.3 %. In long-term, patients with different ACS subtypes had similar cumulative incidence of strokes, although the incidence of in-hospital strokes was highest among myocardial infarction patients. Stroke mortality rate was 32.5 % (n=185/570). The majority (88.8 %) of strokes were ischemic with the proportion being most substantial for in-hospital strokes (95.6 %). Conclusions: The risk of stroke among patients treated for ACS and the related mortality are still notable in a contemporary setting. A distinctive majority of strokes following ACS were ischemic especially early on after ACS.publishedVersionPeer reviewe