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Experimental data from the NA49 collaboration show an unexpectedly steep rise of the rapidity width of the ϕ meson as function of beam energy, which was suggested as possible interesting signal for novel physics. In this work we show that the Ultra-relativistic Quantum-Molecular-Dynamics (UrQMD) model is able to reproduce the shapes of the rapidity distributions of most measured hadrons and predicts a common linear increase of the width for all hadrons. Only when following the exact same analysis technique and experimental acceptance of the NA49 and NA61/SHINE collaborations, we find that the extracted value of the rapidity width of the ϕ increases drastically for the highest beam energy. We conclude that the observed steep increase of the ϕ rapidity width is a problem of limited detector acceptance and the simplified Gaussian fit approximation.
First measurements of hadron(h)−Λ azimuthal angular correlations in p−Pb collisions at sNN−−−√ = 5.02 TeV using the ALICE detector at the LHC are presented. These correlations are used to separate the production of associated Λ baryons into three different kinematic regions, namely those produced in the direction of the trigger particle (near-side), those produced in the opposite direction (away-side), and those whose production is uncorrelated with the jet-axis (underlying event). The per-trigger associated Λ yields in these regions are extracted, along with the near- and away-side azimuthal peak widths, and the results are studied as a function of associated particle pT and event multiplicity. Comparisons with the DPMJET event generator and previous measurements of the ϕ(1020) meson are also made. The final results indicate that strangeness production in the highest multiplicity p−Pb collisions is enhanced relative to low multiplicity collisions in the jet-like regions, as well as the underlying event. The production of Λ relative to charged hadrons is also enhanced in the underlying event when compared to the jet-like regions. Additionally, the results hint that strange quark production in the away-side of the jet is modified by soft interactions with the underlying event.
Measurements of (anti)deuteron and (anti)3He production in the rapidity range |y|< 0.5 as a function of the transverse momentum and event multiplicity in Xe−Xe collisions at a center-of-mass energy per nucleon−nucleon pair of sNN−−−√ = 5.44 TeV are presented. The coalescence parameters B2 and B3 are measured as a function of the transverse momentum per nucleon. The ratios between (anti)deuteron and (anti)3He yields and those of (anti)protons and pions are reported as a function of the mean charged-particle multiplicity density, and compared with two implementations of the statistical hadronization model (SHM) and with coalescence predictions. The elliptic flow of (anti)deuterons is measured for the first time in Xe−Xe collisions and shows features similar to those already observed in Pb−Pb collisions, i.e., the mass ordering at low transverse momentum and the meson−baryon grouping at intermediate transverse momentum. The production of nuclei is particularly sensitive to the chemical freeze-out temperature of the system created in the collision, which is extracted from a grand-canonical-ensemble-based thermal fit, performed for the first time including light nuclei along with light-flavor hadrons in Xe−Xe collisions. The extracted chemical freeze-out temperature Tchem = (154.2 ± 1.1) MeV in Xe−Xe collisions is similar to that observed in Pb−Pb collisions and close to the crossover temperature predicted by lattice QCD calculations.
The transverse momentum (pT) differential production cross section of the promptly-produced charm-strange baryon Ξ0c (and its charge conjugate Ξ0c¯¯¯¯¯¯) is measured at midrapidity via its hadronic decay into π+Ξ− in p−Pb collisions at a centre-of-mass energy per nucleon−nucleon collision sNN−−−√ = 5.02 TeV with the ALICE detector at the LHC. The Ξ0c nuclear modification factor (RpPb), calculated from the cross sections in pp and p−Pb collisions, is presented and compared with the RpPb of Λ+c baryons. The ratios between the pT-differential production cross section of Ξ0c baryons and those of D0 mesons and Λ+c baryons are also reported and compared with results at forward and backward rapidity from the LHCb Collaboration. The measurements of the production cross section of prompt Ξ0c baryons are compared with a model based on perturbative QCD calculations of charm-quark production cross sections, which includes only cold nuclear matter effects in p−Pb collisions, and underestimates the measurement by a factor of about 50. This discrepancy is reduced when the data is compared with a model in which hadronisation is implemented via quark coalescence. The pT-integrated cross section of prompt Ξ0c-baryon production at midrapidity extrapolated down to pT = 0 is also reported. These measurements offer insights and constraints for theoretical calculations of the hadronisation process. Additionally, they provide inputs for the calculation of the charm production cross section in p−Pb collisions at midrapidity.
Investigating strangeness enhancement with multiplicity in pp collisions using angular correlations
(2024)
A study of strange hadron production associated with hard scattering processes and with the underlying event is conducted to investigate the origin of the enhanced production of strange hadrons in small collision systems characterised by large charged-particle multiplicities. For this purpose, the production of the single-strange meson K0S and the double-strange baryon Ξ± is measured, in each event, in the azimuthal direction of the highest-pT particle (``trigger" particle), related to hard scattering processes, and in the direction transverse to it in azimuth, associated with the underlying event, in pp collisions at s√=5.02 TeV and s√=13 TeV using the ALICE detector at the LHC. The per-trigger yields of K0S and Ξ± are dominated by the transverse-to-leading production (i.e., in the direction transverse to the trigger particle), whose contribution relative to the toward-leading production is observed to increase with the event charged-particle multiplicity. The transverse-to-leading and the toward-leading Ξ±/K0S yield ratios increase with the multiplicity of charged particles, suggesting that strangeness enhancement with multiplicity is associated with both hard scattering processes and the underlying event. The relative production of Ξ± with respect to K0S is higher in transverse-to-leading processes over the whole multiplicity interval covered by the measurement. The K0S and Ξ± per-trigger yields and yield ratios are compared with predictions of three different phenomenological models, namely PYTHIA 8.2 with the Monash tune, PYTHIA 8.2 with ropes and EPOS LHC. The comparison shows that none of them can quantitatively describe either the transverse-to-leading or the toward-leading yields of K0S and Ξ±.
The first measurement of the impact-parameter dependent angular anisotropy in the decay of coherently photoproduced ρ0 mesons is presented. The ρ0 mesons are reconstructed through their decay into a pion pair. The measured anisotropy corresponds to the amplitude of the cos(2ϕ) modulation, where ϕ is the angle between the two vectors formed by the sum and the difference of the transverse momenta of the pions, respectively. The measurement was performed by the ALICE Collaboration at the LHC using data from ultraperipheral Pb−Pb collisions at a center-of-mass energy of sNN−−−√ = 5.02 TeV per nucleon pair. Different impact-parameter regions are selected by classifying the events in nuclear-breakup classes. The amplitude of the cos(2ϕ) modulation is found to increase by about one order of magnitude from large to small impact parameters. Theoretical calculations, which describe the measurement, explain the cos(2ϕ) anisotropy as the result of a quantum interference effect at the femtometer scale that arises from the ambiguity as to which of the nuclei is the source of the photon in the interaction.
he first measurement of 3ΛH and 3Λ¯¯¯¯H¯¯¯¯ differential production with respect to transverse momentum and centrality in Pb−Pb collisions at sNN−−−√=5.02~TeV is presented. The 3ΛH has been reconstructed via its two-charged-body decay channel, i.e., 3ΛH→3He+π−. A Blast-Wave model fit of the pT-differential spectra of all nuclear species measured by the ALICE collaboration suggests that the 3ΛH kinetic freeze-out surface is consistent with that of other nuclei. The ratio between the integrated yields of 3ΛH and 3He is compared to predictions from the statistical hadronisation model and the coalescence model, with the latter being favoured by the presented measurements.
Six C-even states, denoted as X, with quantum numbers JPC=0−+, 1±+, or 2±+, are searched for via the e+e−→γD±sD∗∓s process using (1667.39±8.84) pb−1 of e+e− collision data collected with the BESIII detector operating at the BEPCII storage ring at center-of-mass energy of s√=(4681.92±0.30) MeV. No statistically significant signal is observed in the mass range from 4.08 to 4.32 GeV/c2. The upper limits of σ[e+e−→γX]⋅B[X→D±sD∗∓s] at a 90% confidence level are determined.
Using data samples with an integrated luminosity of 4.67 fb−1 collected by the BESIII detector operating at the BEPCII collider, we search for the process e+e−→η′ψ(2S) at center-of-mass energies from 4.66 to 4.95 GeV. No significant signal is observed, and upper limits for the Born cross sections σB(e+e−→η′ψ(2S)) at the 90\% confidence level are determined.
Using a sample of (10087±44)×106 𝐽/𝜓 events, which is about 45 times larger than that was previously analyzed, a further investigation on the 𝐽/𝜓→𝛾3(𝜋+𝜋−) decay is performed. A significant distortion at 1.84 GeV/𝑐2 in the line shape of the 3(𝜋+𝜋−) invariant mass spectrum is observed for the first time, which could be resolved by two overlapping resonant structures, 𝑋(1840) and 𝑋(1880). The new state 𝑋(1880) is observed with a statistical significance larger than 10𝜎. The mass and width of 𝑋(1880) are determined to be 1882.1±1.7±0.7 MeV/𝑐2 and 30.7±5.5±2.4 MeV, respectively, which indicates the existence of a 𝑝¯ 𝑝 bound state.
Using data samples collected with the BESIII detector operating at the BEPCII storage ring, the cross section of the inclusive process e+e−→η+X, normalized by the total cross section of e+e−→hadrons, is measured at eight center-of-mass energy points from 2.0000 GeV to 3.6710 GeV. These are the first measurements with momentum dependence in this energy region. Our measurement shows a significant discrepancy from calculations with the existing fragmentation functions. To address this discrepancy, a new QCD analysis is performed at the next-to-next-to-leading order with hadron mass corrections and higher twist effects, which can explain both the established high-energy data and our measurements reasonably well.
Bei der Zeitschrift "DGaaE - Nachrichten" handelt es sich um das offizielle Publikations-Organ der "Deutschen Gesellschaft für allgemeine und angewandte Entomologie e.V.". Die Hefte erscheinen jährlich drei bis vier mal und sind seit dem Jahr 1987 verfügbar. Die Zeitschrift dient der Kommunikation der Vereinsmitglieder untereinander und informiert über Tätigkeiten und Veranstaltungen des Vereins. Ebenfalls werden hier wissenschafltiche Erkenntnisse aus den Arbeitsgruppen publiziert. Selbsdarstellung der DGaaE: Ziele: In der Deutschen Gesellschaft für allgemeine und angewandte Entomologie sind die in Forschung und Praxis beruflich und aus Berufung tätigen Entomologen vereinigt. Die Gesellschaft ist 1976 aus den beiden traditionsreichen Verbänden Deutsche Entomologische Gesellschaft (DEG) und Deutsche Gesellschaft für angewandte Entomologie (DGaE) hervorgegangen. Aufgabe der Gesellschaft ist es, das Wissen über Entomologie und die Erforschung entomologischer Probleme zu fördern. Der Erfüllung dieser Aufgaben dient die Gesellschaft, indem sie vor allem die persönlichen Verbindungen, den Informationsaustausch und die Zusammenarbeit mit haupt- und nebenberuflich tätigen Entomologen und mit wissenschaftlichen Gesellschaften im In- und Ausland fördert. Tätigkeiten: Die DGaaE veranstaltet alle zwei Jahre eine Vortragstagung. Über verschiedene entomologische Themenbereiche bestehen aktive Arbeitskreise, die z. T. gemeinsam mit anderen Gesellschaften geführt werden. Für besondere Leistungen in der entomologischen Grundlagenforschung verleiht die Gesellschaft in unregelmäßigen Abständen die Fabricius-Medaille, auf dem Gebiet der angewandten Forschung die Karl-Escherich-Medaille und auf dem Gebiet der Systematik und Faunistik die Meigen-Medaille. Alle zwei Jahre verleiht die Gesellschaft den Förderpreis der Weiss/Wiehe-Stiftung für die herausragende Arbeit eines jungen Wissenschaftlers über ein entomologisches Thema (z. B. für eine Dissertation).
L'association "Les Naturalistes Vendéens" publie un bulletin d'information trimestriel ("Lettre des Naturalistes Vendéens") et une revue scientifique annuelle ("Le Naturaliste Vendéen"). Les sommaires de chaque numéro de la revue peuvent être consultés (http://www.naturalistes-vendeens.org/publication/index.html#Naturaliste%20Vend%C3%A9en) et les numéros épuisés sont téléchargeables au format .pdf.
Die Epoche der Weimarer Republik war gekennzeichnet durch eine Vielzahl von Umbrüchen im politischen, ökonomischen und gesellschaftlichen Bereich. Diese durch den Ersten Weltkrieg verursachten radikalen Veränderungen der Lebensverhältnisse hatten auch einen weitreichenden Einfluss auf den Alltag und die öffentliche Wahrnehmung der Frauen dieser Zeit: So konnten diese ab 1918 an den Wahlen teilnehmen, konnten sich an allen deutschen Universitäten einschreiben und in bestimmtem Maße finanziell unabhängig werden. Das Bild der so genannten "Neuen Frau", das gleichzeitig in der Öffentlichkeit generiert wurde, war insbesondere gekennzeichnet durch innerliche und äußerliche Emanzipation und stellte damit einen radikalen Gegenpol zur traditionellen Weiblichkeit des 19. Jahrhunderts dar. Viele Facetten der "Neuen Frau" sind in der Forschung weitgehend erschlossen - die sportliche Frau, die automobile Frau, die Frau als flapper oder garçonne - nur einer Ausprägung des neuen Frauentypus wurde bisher wenig Beachtung geschenkt: der Frau als Verbrecherin. Ziel der vorliegenden interdisziplinär und medienkomparatistisch angelegten Dissertation ist es daher, übergreifende Semantiken und Ästhetiken der geschlechtsspezifischen Verbrechensdarstellung in der Weimarer Republik offenzulegen und die unterschiedlich erzeugten, vermittelten und klassifizierenden Vorstellungen von Verbrecherinnen zu analysieren und zu kontextualisieren. Das zugrundeliegende Material umfasst dabei fachwissenschaftliche, publizistische und literarische Darstellungen von Verbrecherinnen, wobei das Hauptaugenmerk auf der Analyse von Artikeln aus Illustrierten Magazinen liegt, da diese, neben Radio und Film, zu den wirkungsmächtigsten Medien der Weimarer Republik gehören.
Die von der Arbeitsgemeinschaft Forstliche Standorts- und Vegetationskunde (AFSV) herausgegebene Fachzeitschrift soll wichtige Forschungsergebnisse kommunizieren und Impulse geben. Ab dem Jahr 2008 begann sich das Themenspektrum der Vorläufer-Zeitschrift "Waldökologie online" (ISSN 1604-7103) durch einen Zusammenschluss mit dem traditionsreichen "Archiv für Naturschutz und Landschaftsforschung" (ISSN 0003-9306) zu erweitern. Die Fusionierung unter dem neuen Titel "Waldökologie, Landschaftsforschung und Naturschutz" war mit Heft 7 (2009) endgültig vollzogen.
The PhD addresses the feasibility of reconstructing open charm mesons with the Compressed Baryonic Matter experiment, which will be installed at the FAIR accelerator complex at Darmstadt/Germany. The measurements will be carried out by means of a dedicated Micro Vertex Detector (MVD), which will be equipped with CMOS Monolithic Active Pixel Sensors (MAPS). The feasibility of reconstructing the particles with a proposed detector setup was studied.
To obtain conclusive results, the properties of a MAPS prototype were measured in a beam test at the CERN-SPS accelerator. Based on the results achieved, a dedicated simulation software for the sensors was developed and implemented into the software framework of CBM (CBMRoot). Simulations on the reconstruction of D0-mesons were carried out. It is concluded that the reconstruction of those particles is possible.
The PhD introduces the physics motivation of doing open charm measurements, represents the results of the measurements of MAPS and introduces the innovative simulation model for those sensors as much as the concept and results of simulations of the D0 reconstruction.
Why do banks issue contingent convertible debt? To answer this question we study comprehensive data covering all issues by publicly traded banks in Europe of contingent convertible bonds (CoCos) that count as additional tier 1 capital (AT1). We find that banks with lower asset volatility are more likely to issue AT1 CoCos than their riskier counterparts, but that CDS spreads do not react following issue announcements. Our estimates therefore suggest that agency costs play a crucial role in banks' ability to successfully issue CoCos. The agency costs may be higher for CoCos than for equity explaining why we observe riskier or lowly capitalized banks to issue equity rather than CoCos.
Die Zeitschrift Tuexenia wird von der Floristisch-Soziologischen Arbeitsgemeinschaft e. V. (FlorSoz) herausgegeben und publiziert vorwiegend deutsch- und englischsprachige Originalarbeiten über floristische und vegetationskundliche Untersuchungen in Zentraleuropa, ihre theoretischen Grundlagen und Anwendungen in der Praxis. Sie erscheint in der Regel jährlich in einem Band mit rund 400 Seiten.
Die in Tuexenia publizierten Arbeiten werden in zahlreichen Referateorganen berücksichtigt, u.a. im Web of Science (Impact Factor: 1.516 nach Journal Citation Report 2013, Science Edition).
Weitere Informationen zu FlorSoz und zur Zeitschrift sind unter www.tuexenia.de verfügbar.
Over the last few decades, considerable attention has focused on small-scale studies of invasive plants and invaded systems. Unfortunately, small scale studies rarely provide comprehensive insight into the complexities of biological invasions at macroscales. Systematic and repeated monitoring of biological invasions at broad scales are rare. In this report, we highlight a unique invasive plant database from the national Forest Inventory and Analysis (FIA) program of the United States Forest Service. We demonstrate the importance and capability of this subcontinental-wide database by showcasing several critical macroscale invasion patterns that have emerged from its initial analysis: (1) large portion of the forests systems (39%) in the United States are impacted by invasive plants, (2) forests in the eastern United States harbor more invasive species than the western regions, (3) human land-use legacies at regional to national scalesb may drive large-scale invasion patterns. This accumulated dataset, which continues to grow in temporal richness with repeated measurements, will allow the understanding of invasion patterns and processes at multi-spatial and temporal scales. Such insights are not possible from smaller-scale studies, illustrating the benefit that can be gained by investing in the development of regional to continental-wide invasion monitoring programs elsewhere.