817 research outputs found

    The inverse Laplace transform as the ultimate tool for transverse mass spectra

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    New high statistics data from the second generation of ultrarelativistic heavy-ion experiments open up new possibilities in terms of data analysis. To fully utilize the potential we propose to analyze the m⊄m_\perp-spectra of hadrons using the inverse Laplace transform. The problems with its inherent ill-definedness can be overcome and several applications in other fields like biology, chemistry or optics have already shown its feasability. Moreover, the method also promises to deliver upper bounds on the total information content of the spectra, which is of big importance for all other means of analysis. Here we compute several Laplace inversions from different thermal scenarios, both analytically and numerically, to test the efficiency of the method. Especially the case of a two component structure, related to a possible first order phase transition to a quark gluon plasma, is closer investigated and it is shown that at least a signal to noise ratio of 10410^4 is necessary to resolve two individual components.Comment: 13 pages (PostScript, including figures), BNL-NTHES

    Abaloparatide: an anabolic treatment to reduce fracture risk in postmenopausal women with osteoporosis

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    Objective Fractures due to osteoporosis represent a serious burden on patients and healthcare systems. The objective of this review is to provide an overview of the anabolic agent abaloparatide (ABL) for the treatment of postmenopausal women with osteoporosis at high risk for fracture. Methods A literature review was conducted using PubMed to identify articles focused on ABL published prior to February 10, 2020, using the search term “abaloparatide”. Results ABL, a synthetic analog of human parathyroid hormone-related protein, increased bone mineral density (BMD), improved bone microarchitecture, and increased bone strength in preclinical and clinical studies. The pivotal phase 3 trial ACTIVE and its extension (ACTIVExtend) demonstrated the efficacy of initial treatment with ABL for 18 months followed by sequential treatment with alendronate (ALN) for an additional 24 months to reduce the risk of vertebral, nonvertebral, clinical, and major osteoporotic fractures and to increase BMD in postmenopausal women with osteoporosis. Discontinuations from ACTIVE were slightly more common in ABL-treated patients due to dizziness, palpitations, nausea, and headache. Post hoc analyses of ACTIVE and ACTIVExtend support the efficacy and safety of ABL in relevant subpopulations including postmenopausal women with various baseline risk factors, women ≄80 years, women with type 2 diabetes mellitus, and women with renal impairment. Conclusions ABL is an effective and well-tolerated treatment for women with postmenopausal osteoporosis at high risk for fracture. Its therapeutic effects are sustained with subsequent ALN therapy

    A quark model analysis of the charge symmetry breaking in nuclear force

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    In order to investigate the charge symmetry breaking (CSB) in the short range part of the nuclear force, we calculate the difference of the masses of the neutron and the proton, ΔM\Delta {\rm M}, the difference of the scattering lengths of the p-p and n-n scatterings, Δa\Delta a, and the difference of the analyzing power of the proton and the neutron in the n-p scattering, ΔA(ξ)\Delta A(\theta), by a quark model. In the present model the sources of CSB are the mass difference of the up and down quarks and the electromagnetic interaction. We investigate how much each of them contributes to ΔM\Delta {\rm M}, Δa\Delta a and ΔA(ξ)\Delta A(\theta). It is found that the contribution of CSB of the short range part in the nuclear force is large enough to explain the observed ΔA(ξ)\Delta A(\theta), while Δa\Delta a is rather underestimated.Comment: 26 pages,6 figure

    Evidence for the formation of magnetic moments in the cuprate superconductor Hg0.8_{0.8}Cu0.2_{0.2}Ba2_2Ca2_2Cu3_3O8+ÎŽ_{8+\delta} below TcT_c seen by NQR

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    We report pure zero field nuclear magnetic resonance (NQR) measurements on the optimally doped three layer high-Tc T_{c} -compounds HgBaCaCuO and HgBaCaCuO(F) with TcT_c 134 K. Above Tc T_{c} two Cu NQR line pairs are observed in the spectra corresponding to the two inequivalent Cu lattice sites. Below Tc T_{c} the Cu NQR spectra show additional lines leading to the extreme broadened Cu NQR spectra at 4.2 K well known for the HgBaCaCuO compounds. The spin-lattice relaxation curves follow a triple exponential function with coefficients depend onto the saturation time (number of saturation pulses), whereas the spin-spin relaxation curve is described by a single exponential function. From the spin-lattice relaxation we deduced a complete removal of the Kramers degeneracy of the Cu quadrupole indicating that the additional lines are due to a Zeemann splitting of the 63/65^{63/65}Cu lines due to the spontaneous formation of magnetic moments within the CuO layers. Below 140 K, the spectra are well fitted by a number of 6 63/65^{63/65}Cu line pairs. From the number of the Cu lines, the position of the lines relative to each other and the complete removal of the Kramers degeneracy we deduced an orientation of the magnetic moments parallel to the symmetry axis of the electric field gradient tensor with magnitudes of the order of 1000 G. We also discuss the possible microscopic origin of the observed internal magnetic fields.Comment: 11 pages, 12 figure

    Multicanonical Multigrid Monte Carlo

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    To further improve the performance of Monte Carlo simulations of first-order phase transitions we propose to combine the multicanonical approach with multigrid techniques. We report tests of this proposition for the dd-dimensional Ί4\Phi^4 field theory in two different situations. First, we study quantum tunneling for d=1d = 1 in the continuum limit, and second, we investigate first-order phase transitions for d=2d = 2 in the infinite volume limit. Compared with standard multicanonical simulations we obtain improvement factors of several resp. of about one order of magnitude.Comment: 12 pages LaTex, 1 PS figure appended. FU-Berlin preprint FUB-HEP 9/9

    A Virtual File System Interface for Computational Grids

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    Observation of Precipitation Evolution in Fe-Ni-Mn-Ti-Al Maraging Steel by Atom Probe Tomography

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    We describe the full decomposition sequence in an Fe-Ni-Mn-Ti-Al maraging steel during isothermal annealing at 550 °C. Following significant pre-precipitation clustering reactions within the supersaturated martensitic solid solution, (Ni,Fe)3Ti and (Ni,Fe)3(Al,Mn) precipitates eventually form after isothermal aging for ~60 seconds. The morphology of the (Ni,Fe)3Ti particles changes gradually during aging from predominantly plate-like to rod-like, and, importantly, Mn and Al were observed to segregate to these precipitate/matrix interfaces. The (Ni,Fe)3(Al,Mn) precipitates occurred at two main locations: uniformly within the matrix and at the periphery of the (Ni,Fe)3Ti particles. We relate this latter mode of precipitation to the Mn-Al segregation

    Homogeneous nucleation of quark-gluon plasma, finite size effects and long-lived metastable objects

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    The general formalism of homogeneous nucleation theory is applied to study the hadronization pattern of the ultra-relativistic quark-gluon plasma (QGP) undergoing a first order phase transition. A coalescence model is proposed to describe the evolution dynamics of hadronic clusters produced in the nucleation process. The size distribution of the nucleated clusters is important for the description of the plasma conversion. The model is most sensitive to the initial conditions of the QGP thermalization, time evolution of the energy density, and the interfacial energy of the plasma-hadronic matter interface. The rapidly expanding QGP is first supercooled by about ΔT=T−Tc=4−6\Delta T = T - T_c = 4-6 %. Then it reheats again up to the critical temperature T_c. Finally it breaks up into hadronic clusters and small droplets of plasma. This fast dynamics occurs within the first 5−10fm/c5-10 fm/c. The finite size effects and fluctuations near the critical temperature are studied. It is shown that a drop of longitudinally expanding QGP of the transverse radius below 4.5 fm can display a long-lived metastability. However, both in the rapid and in the delayed hadronization scenario, the bulk pion yield is emitted by sources as large as 3-4.5 fm. This may be detected experimentally both by a HBT interferometry signal and by the analysis of the rapidity distributions of particles in narrow p_T-intervals at small p_T on an event-by-event basis.Comment: 29 pages, incl. 12 figures and 1 table; to be published in Phys. Rev.
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