391 research outputs found

    Interactions between Travel Behaviour, Accessibility and Personal Characteristics

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    This paper explores the impacts of personal characteristics and the spatial structure on travel behaviour, especially mode choice. The spatial structure is described among other things by accessibility measures. The models are estimated using structural equation modelling (SEM). The models are based on the 1992 Upper Austrian travel survey and the Upper Austrian transport model.   The results highlight the key roles of car ownership, gender and work status in explaining the observed level and intensity of travel. The most important spatial variable is the number of facilities which can be reached by a household. The municipality based variables and the accessibility measures have rather little explanatory power. The reasons for this low explanatory power are considered. Although the findings in this study indicate that the spatial structure is not a decisive determinant of traffic, the results provide useful hints for possible policy alternatives

    The strong coupling from a nonperturbative determination of the Λ\Lambda parameter in three-flavor QCD

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    We present a lattice determination of the Λ\Lambda parameter in three-flavor QCD and the strong coupling at the Z pole mass. Computing the nonperturbative running of the coupling in the range from 0.20.2\,GeV to 7070\,GeV, and using experimental input values for the masses and decay constants of the pion and the kaon, we obtain ΛMS(3)=341(12)\Lambda_{\overline{\rm MS}}^{(3)}=341(12)\,MeV. The nonperturbative running up to very high energies guarantees that systematic effects associated with perturbation theory are well under control. Using the four-loop prediction for ΛMS(5)/ΛMS(3)\Lambda_{\overline{\rm MS}}^{(5)}/\Lambda_{\overline{\rm MS}}^{(3)} yields αMS(5)(mZ)=0.11852(84)\alpha^{(5)}_{\overline{\rm MS}}(m_{\rm Z}) = 0.11852(84).Comment: Correction in the comparison to the LHC value for alpha(1.5TeV) which was given by CMS in the 5-flavor theory. The agreement is improved. Also 1 Reference added and a few typos correcte

    The Λ\Lambda-parameter in 3-flavour QCD and αs(mZ)\alpha_s(m_Z) by the ALPHA collaboration

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    We present results by the ALPHA collaboration for the Λ\Lambda-parameter in 3-flavour QCD and the strong coupling constant at the electroweak scale, αs(mZ)\alpha_s(m_Z), in terms of hadronic quantities computed on the CLS gauge configurations. The first part of this proceedings contribution contains a review of published material \cite{Brida:2016flw,DallaBrida:2016kgh} and yields the Λ\Lambda-parameter in units of a low energy scale, 1/Lhad1/L_{\rm had}. We then discuss how to determine this scale in physical units from experimental data for the pion and kaon decay constants. We obtain ΛMS(3)=332(14)\Lambda_{\overline{\rm MS}}^{(3)} = 332(14) MeV which translates to αs(MZ)=0.1179(10)(2)\alpha_s(M_Z)=0.1179(10)(2) using perturbation theory to match between 3-, 4- and 5-flavour QCD.Comment: 21 pages. Collects contributions of A. Ramos, S. Sint and R. Sommer to the 34th annual International Symposium on Lattice Field Theory; LaTeX input encoding problem fixe

    B-physics with Nf=2N_f=2 Wilson fermions

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    We report the final results of the ALPHA collaboration for some B-physics observables: fBf_B, fBsf_{B_s} and mbm_b. We employ CLS configurations with 2 flavors of O(a)O(a) improved Wilson fermions in the sea and pion masses ranging down to 190 MeV. The b-quark is treated in HQET to order 1/mb1/m_b. The renormalization, the matching and the improvement were performed non-perturbatively, and three lattice spacings reaching a=0.048a=0.048 fm are used in the continuum extrapolation

    Decay constants of B-mesons from non-perturbative HQET with two light dynamical quarks

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    We present a computation of B-meson decay constants from lattice QCD simulations within the framework of Heavy Quark Effective Theory for the b-quark. The next-to-leading order corrections in the HQET expansion are included non-perturbatively. Based on Nf=2 gauge field ensembles, covering three lattice spacings a (0.08-0.05)fm and pion masses down to 190MeV, a variational method for extracting hadronic matrix elements is used to keep systematic errors under control. In addition we perform a careful autocorrelation analysis in the extrapolation to the continuum and to the physical pion mass limits. Our final results read fB=186(13)MeV, fBs=224(14)MeV and fBs/fB=1.203(65). A comparison with other results in the literature does not reveal a dependence on the number of dynamical quarks, and effects from truncating HQET appear to be negligible.Comment: 16 pages including figures and table

    The b-quark mass from non-perturbative Nf=2N_f=2 Heavy Quark Effective Theory at O(1/mh)O(1/m_h)

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    We report our final estimate of the b-quark mass from Nf=2N_f=2 lattice QCD simulations using Heavy Quark Effective Theory non-perturbatively matched to QCD at O(1/mh)O(1/m_h). Treating systematic and statistical errors in a conservative manner, we obtain mbMS(2GeV)=4.88(15)\overline{m}_{\rm b}^{\overline{\rm MS}}(2 {\rm GeV})=4.88(15) GeV after an extrapolation to the physical point.Comment: 15 pages including figures and tables; as published in Phys.Lett.B / typo in table 4 corrected / footnote 1 expande

    CP-Violating Asymmetries in Charmless Non-Leptonic Decays BPP,PV,VVB \to PP, PV, VV in the Factorization Approach

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    We present estimates of the direct (in decay amplitudes) and indirect (mixing- induced) CP-violating asymmetries in the non-leptonic charmless two-body decay rates for BPPB \to PP, BPVB \to PV and BVVB \to VV decays and their charged conjugates, where P(V) is a light pseudoscalar (vector) meson. These estimates are based on a generalized factorization approach making use of next-to-leading order perturbative QCD contributions which generate the required strong phases. No soft final state interactions are included. We study the dependence of the asymmetries on a number of input parameters and show that there are at least two (possibly three) classes of decays in which the asymmetries are parametrically stable in this approach. The decay modes of particular interest are: \optbar{B^0} \to \pi^+ \pi^-, \optbar{B^0} \to K_S^0 \pi^0, \optbar{B^0} \to K_S^0 \eta^\prime, \optbar{B^0} \to K_S^0 \eta and \optbar{B^0} \to \rho^+ \rho^-. Likewise, the CP-violating asymmetry in the decays \optbar{B^0} \to K_S^0 h^0 with h0=π0,KS0,η,ηh^0=\pi^0,K_S^0, \eta,\eta^\prime is found to be parametrically stable and large. Measurements of these asymmetries will lead to a determination of the phases sin2α\sin 2\alpha and sin2β\sin 2 \beta and we work out the relationships in these modes in the present theoretical framework. We also show the extent of the so-called "penguin pollution" in the rate asymmetry ACP(π+π)A_{CP}(\pi^+ \pi^-) and of the "tree shadow" in the asymmetry ACP(KS0η)A_{CP}(K_S^0\eta^\prime) which will effect the determination of sin2α\sin 2 \alpha and sin2β\sin 2 \beta from the respective measurements. CP-violating asymmetries in B±π±ηB^\pm \to \pi^\pm \eta^\prime, B±K±ηB^\pm \to K^{*\pm} \eta, B±K±ηB^\pm \to K^{*\pm} \eta^\prime and B±K±ρ0B^\pm \to K^{*\pm}\rho^0 are potentially interesting and are studied here.Comment: 42 pages (LaTex) including 19 figures, requires epsfig.sty; submitted to Phys. Rev.

    Pediatric Trauma and Trauma Team Activation in a Swiss Pediatric Emergency Department: An Observational Cohort Study.

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    BACKGROUND Trauma is one of the most common causes of death in childhood, but data on severely injured Swiss children are absent from existing national registries. Our aim was to analyze trauma activations and the profiles of critically injured children at a tertiary, non-academic Swiss pediatric emergency department (PED). In the absence of a national pediatric trauma database, this information may help to guide the design of infrastructure, processes within organizations, training, and policies. METHODS A retrospective analysis of pediatric trauma patients in a prospective resuscitation database over a 2-year period. Critically injured trauma patients under the age of 16 years were included. Patients were described with established triage and injury severity scales. Statistical evaluation included logistic regression analysis. RESULTS A total of 82 patients matched one or more of the study inclusion criteria. The most frequent age group was 12-15 years, and 27% were female. Trauma team activation (TTA) occurred with 49 patients (59.8%). Falls were the most frequent mechanism of injury, both overall and for major trauma. Road-traffic-related injuries had the highest relative risk of major trauma. In the multivariate analysis, patients receiving medicalized transport were more likely to trigger a TTA, but there was no association between TTA and age, gender, or Injury Severity Score (ISS). Nineteen patients (23.2%) sustained major trauma with an ISS > 15. Injuries of Abbreviated Injury Scale severity 3 or greater were most frequent to the head, followed by abdomen, chest, and extremities. The overall mortality rate in the cohort was 2.4%. CONCLUSIONS Major trauma presentations only comprise a small proportion of the total patient load in the PED, and trauma team activation does not correlate with injury severity. Low exposure to high-acuity patients highlights the importance of deliberate learning and simulation for all professionals in the PED. Our findings indicate that high priority should be given to training in the management of severely injured children in the PED. The leading major trauma mechanisms were preventable, which should prompt further efforts in injury prevention

    Progress and status of APEmille

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    We report on the progress and status of the APEmille project: a SIMD parallel computer with a peak performance in the TeraFlops range which is now in an advanced development phase. We discuss the hardware and software architecture, and present some performance estimates for Lattice Gauge Theory (LGT) applications.Comment: Talk presented at LATTICE97, 3 pages, Late
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