3,560 research outputs found

    Update on Counting Valence Quarks at RHIC

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    We update our former analysis of the Nuclear Modification Factors (NMF) for different hadron species at RHIC and LHC. This update is motivated by the new experimental data from STAR which presents differences with the preliminary data used to fix some of the parameters in our model. The main change is the use of AKK fragmentation functions for the hard part of the spectrum and minor adjustments of the coalescence (soft) contribution. We confirm that observation of the NMF for the f_0 meson can shed light on its quark composition.Comment: 4 pages, 4 figure

    Scalar-tensor theory with EGB term from Einstein Chern-Simons gravity

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    It is shown that the compactification a la Randall Sundrum of the so called, five dimensional Einstein Chern Simons action gravity leads to an action for a four dimensional scalar tensor gravity that includes a Gauss Bonnet term, which belongs to a particular case of the action of the Horndeski theory. The five dimensional action includes new gravitational degrees of freedom that were introduced requiring that the action be invariant under symmetries greater than the usual Poincare or (A)dS symmetries, namely the so called generalized Poincare algebras B5.Comment: To be published in Nucl. Phys.

    Coalescing binary systems of compact objects: Dynamics of angular momenta

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    The end state of a coalescing binary of compact objects depends strongly on the final total mass M and angular momentum J. Since gravitational radiation emission causes a slow evolution of the binary system through quasi-circular orbits down to the innermost stable one, in this paper we examine the corresponding behavior of the ratio J/M^2 which must be less than 1(G/c) or about 0.7(G/c) for the formation of a black hole or a neutron star respectively. The results show cases for which, at the end of the inspiral phase, the conditions for black hole or neutron star formation are not satisfied. The inclusion of spin effects leads us to a study of precession equations valid also for the calculation of gravitational waveforms.Comment: 22 pages, AASTeX and 13 figures in PostScrip

    On attributes of a Rotating Neutron star with a Hyperon core

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    We study the effect of rotation on global properties of neutron star with a hyperon core in an effective chiral model with varying nucleon effective mass within a mean field approach. The resulting gross properties of the rotating compact star sequences are then compared and analyzed with other theoretical predictions and observations from neutron stars. The maximum mass of the compact star predicted by the model lies in the range (1.42.4) M(1.4-2.4) ~M_{\odot} at Kepler frequency ΩK\Omega_K, which is consistant with recent observation of high mass stars thereby reflecting the sensitivity of the underlying nucleon effective mass in the dense matter EoS. We also discuss the implications of the experimental constraints from the flow data from heavy-ion collisions on the global properties of the rotating neutron stars.Comment: 11 Pages, 10 Figures and 2 Table

    In-Hospital and Long-Term Prognosis after Spontaneous Intracerebral Hemorrhage among Young Adults Aged 18-65 Years

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    BACKGROUND: Spontaneous intracerebral hemorrhage (ICH) accounts for 10%-15% of all strokes and has an estimated annual incidence of 5/100,000 in young adults. Limited data on prognosis after ICH in young adults are available. We aimed to identify prognostic predictors after ICH among adults aged 18-65 years. METHODS: We retrospectively selected all patients with ICH from a prospective single-center registry of adults with first stroke before 65 years between 1997 and 2002. We recorded in-hospital mortality as well as mortality and recurrent stroke after discharge until December 1, 2018. For in-hospital analysis, we compared patients that died in-hospital versus patients discharged alive. For long-term analysis, we compared patients that died in follow-up versus patients still alive. Independent prognostic predictors were identified using multivariate analyses. RESULTS: Among 161 patients included, 24 (14.9%) died in-hospital. Among in-hospital survivors, 5-year survival was 92.0%, 10-year survival 78.1%, and 15-year survival 62.0%. After median follow-up of 17 years, 47.4% of patients died, 18 patients had ischemic stroke, and 6 recurrent ICH. Regarding in-hospital prognosis, coma at admission (OR .02 [.00-.11]) was independent predictor for mortality whereas alcoholic habits (OR 12.32 [1.82-83.30]) was independent predictor for survival. An increasing age (OR 1.08 [1.03-1.12]), higher blood glucose levels (OR 1.01 [1.00-1.01]), and hypertension (OR 2.21 [1.22-4.00]) were independent predictors of long-term mortality after ICH. CONCLUSIONS: Alcoholic habits may influence in-hospital survival after ICH in young adults. Long-term mortality in young adults seems to be lower than in elderly and was predicted by higher blood glucose levels and hypertension.info:eu-repo/semantics/publishedVersio

    A global DGLAP analysis of nuclear PDFs

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    In this talk, we shortly report results from our recent global DGLAP analysis of nuclear parton distributions. This is an extension of our former EKS98-analysis improved with an automated χ2\chi^2 minimization procedure and uncertainty estimates. Although our new analysis show no significant deviation from EKS98, a sign of a significantly stronger gluon shadowing could be seen in the RHIC BRAHMS data.Comment: Talk given at EPS HEP 200
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