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Results are presented on event-by-event fluctuations in transverse momentum of charged particles, produced at forward rapidities in p+p, C+C, Si+Si and Pb+Pb collisions at 158 AGeV. Three different characteristics are discussed: the average transverse momentum of the event, the Phi_pT fluctuation measure and two-particle transverse momentum correlations. In the kinematic region explored, the dynamical fluctuations are found to be small. However, a significant system size dependence of Phi_pT is observed, with the largest value measured in peripheral Pb+Pb interactions. The data are compared with predictions of several models. PACS numbers: 14.20.Jn, 13.75.Cs, 12.39.-x
Observation of an exotic S = -2, Q = -2 baryon resonance in proton-proton collisions at the CERN SPS
(2003)
Results of resonance searches in the Xi- pi-, Xi- pi+, antiXi+ pi- and antiXi+ pi+ invariant mass spectra in proton-proton collisions at sqrt s=17.2 GeV are presented. Evidence is shown for the existence of a narrow Xi- pi- baryon resonance with mass of 1.862+/-0.002 GeV/c^2 and width below the detector resolution of about 0.018 GeV/c^2. The significance is estimated to be 4.0 sigma. This state is a candidate for the hypothetical exotic Xi_(3/2)^-- baryon with S = -2, I = 3/2 and a quark content of (d s d s ubar). At the same mass a peak is observed in the Xi- pi+ spectrum which is a candidate for the Xi_(3/2)^0 member of this isospin quartet with a quark content of (d s u s dbar). The corresponding antibaryon spectra also show enhancements at the same invariant mass.
A non-monotonic energy dependence of the K + / pi + ratio with a sharp maximum close to 30 A GeV is observed in central Pb+Pb collisions. Within a statistical model of the early stage, this is interpreted as a sign of the phase transition to a QGP, which causes a sharp change in the energy dependence of the strangeness to entropy ratio. This observation naturally motivates us to study the production of multistrange hyperons (Xi, Omega) as a function of the beam energy. Furthermore it was suggested that the kinematic freeze-out of Omega takes place directly at QGP hadronization. If this is indeed the case, the transverse momentum spectra of the Omega directly reflect the transverse expansion velocity of a hadronizing QGP. In this report we show preliminary NA49 results on Omega - and Omega + production in central Pb+Pb collisions at 40 and 158 A GeV and compare them to measurements of Xi - and Xi + production in central Pb+Pb collisions at 30, 40, 80 and 158 A GeV.
LTAG semantics for questions
(2004)
This papers presents a compositional semantic analysis of interrogatives clauses in LTAG (Lexicalized Tree Adjoining Grammar) that captures the scopal properties of wh- and nonwh-quantificational elements. It is shown that the present approach derives the correct semantics for examples claimed to be problematic for LTAG semantic approaches based on the derivation tree. The paper further provides an LTAG semantics for embedded interrogatives.
Kritik der Gewalt : über den Begriff der Gewalt von Walter Benjamin, Albert Camus und Frantz Fanon
(2004)
Weak function word shift
(2004)
The fact that object shift only affects weak pronouns in mainland Scandinavian is seen as an instance of a more general observation that can be made in all Germanic languages: weak function words tend to avoid the edges of larger prosodic domains. This generalisation has been formulated within Optimality Theory in terms of alignment constraints on prosodic structure by Selkirk (1996) in explaining thedistribution of prosodically strong and weak forms of English functionwords, especially modal verbs, prepositions and pronouns. But a purely phonological account fails to integrate the syntactic licensing conditions for object shift in an appropriate way. The standard semantico-syntactic accounts of object shift, onthe other hand, fail to explain why it is only weak pronouns that undergo object shift. This paper develops an Optimality theoretic model of the syntax-phonology interface which is based on the interaction of syntactic and prosodic factors. The account can successfully be applied to further related phenomena in English and German.
The purpose of this paper is to describe the TüBa-D/Z treebank of written German and to compare it to the independently developed TIGER treebank (Brants et al., 2002). Both treebanks, TIGER and TüBa-D/Z, use an annotation framework that is based on phrase structure grammar and that is enhanced by a level of predicate-argument structure. The comparison between the annotation schemes of the two treebanks focuses on the different treatments of free word order and discontinuous constituents in German as well as on differences in phrase-internal annotation.
Tree-local MCTAG with shared nodes : an analysis of word order variation in German and Korean
(2004)
Tree Adjoining Grammars (TAG) are known not to be powerful enough to deal with scrambling in free word order languages. The TAG-variants proposed so far in order to account for scrambling are not entirely satisfying. Therefore, an alternative extension of TAG is introduced based on the notion of node sharing. Considering data from German and Korean, it is shown that this TAG-extension can adequately analyse scrambling data, also in combination with extraposition and topicalization.
This paper reports on the SYN-RA (SYNtax-based Reference Annotation) project, an on-going project of annotating German newspaper texts with referential relations. The project has developed an inventory of anaphoric and coreference relations for German in the context of a unified, XML-based annotation scheme for combining morphological, syntactic, semantic, and anaphoric information. The paper discusses how this unified annotation scheme relates to other formats currently discussed in the literature, in particular the annotation graph model of Bird and Liberman (2001) and the pie-in-thesky scheme for semantic annotation.