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The measurement of the production of charm jets, identified by the presence of a D0 meson in the jet constituents, is presented in proton-proton collisions at centre-of-mass energies of s√ = 5.02 and 13 TeV with the ALICE detector at the CERN LHC. The D0 mesons were reconstructed from their hadronic decay D0→K−π+ and the respective charge conjugate. Jets were reconstructed from D0-meson candidates and charged particles using the anti-kT algorithm, in the jet transverse momentum range 5<pT;chjet<50 GeV/c, pseudorapidity |ηjet|<0.9−R, and with the jet resolution parameters R = 0.2, 0.4, 0.6. The distribution of the jet momentum fraction carried by a D0 meson along the jet axis (zch||) was measured in the range 0.4<zch||<1.0 in four ranges of the jet transverse momentum. Comparisons of results for different collision energies and jet resolution parameters are also presented. The measurements are compared to predictions from Monte Carlo event generators based on leading-order and next-to-leading-order perturbative quantum chromodynamics calculations. A generally good description of the main features of the data is obtained in spite of a few discrepancies at low pT;chjet. Measurements were also done for R=0.3 at s√ = 5.02 TeV and are shown along with their comparisons to theoretical predictions in an appendix to this paper.
The standard view of the form-meaning interfaces, as embraced by the great majority of contemporary grammatical frameworks, consists in the assumption that meaning can be associated with grammatical form in a one-to-one correspondence. Under this view, composition is quite straightforward, involving concatenation of form, paired with functional application in meaning. In this book, we discuss linguistic phenomena across several grammatical sub-modules (morphology, syntax, semantics) that apparently pose a problem to the standard view, mapping out the potential for deviation from the ideal of one-to-one correspondences, and develop formal accounts of the range of phenomena. We argue that a constraint-based perspective is particularly apt to accommodate deviations from one-to-many correspondences, as it allows us to impose constraints on full structures (such as a complete word or the interpretation of a full sentence) instead of deriving such structures step by step.
Most of the papers in this volume are formulated in a particular constraint-based grammar framework, Head-driven Phrase Structure Grammar. The contributions investigate how the lexical and constructional aspects of this theory can be combined to provide an answer to this question across different linguistic sub-theories.
Transnational Legal History : Erforschung rechtlicher Entwicklungen jenseits nationaler Grenzen
(2023)
SAFE Update April 2024
(2024)
Das Forum Interdisziplinäre Begriffsgeschichte hat in seiner zwölfjährigen Geschichte immer wieder Begriffe an der Schnittstelle von Biologie sowie Gesellschaft und Kultur, insbesondere aber solche des ökologischen Diskurses thematisiert. [...] Das vorliegende, von der Slawistin Tatjana Petzer (Universität Graz) als Gastherausgeberin gestaltete Schwerpunktthema "Ecology in Eastern European Terminology" lässt sich als Fortsetzung dieser Thematiken verstehen. Die Beiträge verdeutlichen, wie Wissenschaftlerinnen und Wissenschaftler osteuropäischer Länder und der Sowjetunion, die oftmals zunächst im engen Kontakt mit westeuropäischen Wissenschaftsentwicklungen standen, aufgrund der späteren, vor allem im Kalten Krieg forcierten Abkoppelung eigenständige Terminologien und Konzepte entwickelten, deren Zusammenhang mit westlichen Ideen dadurch verdeckt waren, und doch mitunter auch wieder auf sie zurückwirkten. Viele der behandelten interdisziplinären Begriffe (Biogeochemie, Biogeozönose, Metabolismus, Regulation oder Geocryologie) thematisieren den heute so intensiv diskutierten Zusammenhang zwischen Ökologie und Geologie.
Die USA - Terra incognita für die meisten Europäer im frühen und mittleren 19. Jahrhundert - spielten als Modell staatswissenschaftlichen, verfassungsrechtlichen und politischen Denkens bei den Vertretern und Verteidigern der monarchischen Herrschaft und ihres Machtgefüges genauso wie bei den Anführern und Anhängern gemäßigter und radikaler Reform-, Oppositions- und Widerstandsbewegungen, aber auch an deutschen Universitäten und Akademien, in literarischen und philosophischen Zirkeln, in Unternehmer- und Verlegerkreisen, Künstlerbünden und der medialen Öffentlichkeit eine zentrale Rolle. Zugleich stellte die Neue Welt ein Sehnsuchtsziel für Freiheitsliebende, politische Flüchtlinge, Auswanderungswillige und Wirtschaftsmigranten, aber auch bisweilen die gefürchtete Endstation für verbannte Gefangene dar: Das Spektrum der Funktionen, Aufgaben, Bilder und Vorstellungen ist breit, das die Vereinigten Staaten von Amerika in der Wahrnehmung der Zeitgenossen im Vor- und Nachmärz einnahmen und das ihnen zugeschrieben wurde - nicht zuletzt auch in der (Emigrations-)Literatur.
The azimuthal (Δφ) correlation distributions between heavy-flavor decay electrons and associated charged particles are measured in pp and p−Pb collisions at sNN−−−√=5.02 TeV. Results are reported for electrons with transverse momentum 4<pT<16 GeV/c and pseudorapidity |η|<0.6. The associated charged particles are selected with transverse momentum 1<pT<7 GeV/c, and relative pseudorapidity separation with the leading electron |Δη|<1. The correlation measurements are performed to study and characterize the fragmentation and hadronization of heavy quarks. The correlation structures are fitted with a constant and two von Mises functions to obtain the baseline and the near- and away-side peaks, respectively. The results from p−Pb collisions are compared with those from pp collisions to study the effects of cold nuclear matter. In the measured trigger electron and associated particle kinematic regions, the two collision systems give consistent results. The Δφ distribution and the peak observables in pp and p−Pb collisions are compared with calculations from various Monte Carlo event generators.
A newly developed observable for correlations between symmetry planes, which characterize the direction of the anisotropic emission of produced particles, is measured in Pb-Pb collisions at sNN−−−√=2.76 TeV with ALICE. This so-called Gaussian Estimator allows for the first time the study of these quantities without the influence of correlations between different flow amplitudes. The centrality dependence of various correlations between two, three and four symmetry planes is presented. The ordering of magnitude between these symmetry plane correlations is discussed and the results of the Gaussian Estimator are compared with measurements of previously used estimators. The results utilizing the new estimator lead to significantly smaller correlations than reported by studies using the Scalar Product method. Furthermore, the obtained symmetry plane correlations are compared to state-of-the-art hydrodynamic model calculations for the evolution of heavy-ion collisions. While the model predictions provide a qualitative description of the data, quantitative agreement is not always observed, particularly for correlators with significant non-linear response of the medium to initial state anisotropies of the collision system. As these results provide unique and independent information, their usage in future Bayesian analysis can further constrain our knowledge on the properties of the QCD matter produced in ultrarelativistic heavy-ion collisions.
Programm Sommersemester 2024, Frankfurter Bürger-Universität, Goethe-Universität Frankfurt am Main
(2024)
What happens at the nexus of the digital divide and human trafficking? This book examines the impact of the introduction of new digital information and communication technology (ICT) as well as lack of access to digital connectivity on human trafficking. The different studies presented in the chapters show the realities for people moving along the Central Mediterranean route from the Horn of Africa through Libya to Europe. The authors warn against an over-optimistic view of innovation as a solution and highlight the relationship between technology and the crimes committed against vulnerable people in search of protection. In this volume, the third in a four-part series Connected and Mobile: Migration and Human Trafficking in Africa, relevant new theories are proposed as tools to understand the dynamics that appear in mobile Africa. Most importantly, the editors identify critical ethical issues in relation to both technology and human trafficking and the nexus between them, helping explore the dimensions of new responsibilities that need to be defined. The chapters in this book represent a collection of well-documented empirical investigations by a young and diverse group of researchers, addressing critical issues in relation to innovation and the perils of our time.
Weimarer Beiträge 66/2020
(2020)
Die Weimarer Beiträge sind eine Zeitschrift für Literaturwissenschaft, aktuelle ästhetische Theorie und Kulturwissenschaft. Zu Ihren Schwerpunkten gehören moderne Literatur im Rahmen anderer Künste und Medien, die Wechselbeziehungen von Literatur, philosophischer und ästhetischer Reflexion sowie die kritische Analyse der Gegenwartskultur.
Weimarer Beiträge 53/2007
(2007)
Die Weimarer Beiträge sind eine Zeitschrift für Literaturwissenschaft, aktuelle ästhetische Theorie und Kulturwissenschaft. Zu Ihren Schwerpunkten gehören moderne Literatur im Rahmen anderer Künste und Medien, die Wechselbeziehungen von Literatur, philosophischer und ästhetischer Reflexion sowie die kritische Analyse der Gegenwartskultur.
Mit dem vorliegenden Eröffnungsband der Medienkomparatistik soll ein neues Forum für medienvergleichende Forschung initiiert werden. Das Zusammenwirken unterschiedlicher Medien und verschiedener medialer Praktiken spielt nicht nur in der gegenwärtigen Alltagswelt eine zunehmend bedeutende Rolle. Vielmehr hat sich in den letzten Jahren, ausgehend von den literatur-, kunst-, und medienwissenschaftlichen Einzeldisziplinen ein fächerübergreifendes Diskussionsfeld herausgebildet, das sich gezielt Fragen des Medienvergleichs und der Interferenz von Medien widmet. Dieser interdisziplinäre Forschungsbereich erlebt derzeit in den Kulturwissenschaften eine erstaunliche Konjunktur. Neben der vergleichenden Methodologie als wichtige heuristische Grundlage besteht eine weitere Zielsetzung der Medienkomparatistik darin, allgemeine Kriterien zur systematischen Erfassung der einzelnen Medien zu entwickeln und ihre jeweiligen Operationsleistungen in sich wandelnden kulturellen Kontexten zu erkunden.
ISOE-Newsletter Nr. 6/2023
(2023)
Bürger-Universität: Gesundheitsfolgen des Klimawandels: Frankfurts Wege zur Klimaanpassung +++ „Insectopolis“: ISOE vergibt Kunststipendium zum Thema Insektenvielfalt in der Stadt +++ Pendelmobilität nachhaltiger gestalten – Empfehlungen aus dem Forschungsprojekt „PendelLabor“ +++ ISOE-Lecture: Soziale Ökologie für Entscheidungsträger*innen +++ Bedrohte Insektenvielfalt in Naturschutzgebieten – Empfehlungen aus dem Forschungsprojekt DINA +++ Transdisziplinäre Forschung – Mehrwert für die Wissenschaft +++ Mobilitätsstudie für die Region Rhein-Main-Neckar – Bausteine für eine multimodale und klimaschonende Mobilität +++ Hessischer Klimabeirat appelliert an Koalitionsparteien: Land Hessen muss beim Klimaschutz entschieden handeln +++ Aus dem ISOE +++ Das ISOE in den Medien +++ Termine +++ Publikationen
Rezensionen zu:
Johannes Diehl, Markus Witte Hebräisches und aramäisches Wörterbuch zum Alten Testament Begründet von Georg Fohrer. 4., völlig neu bearb. Aufl., De Gruyter, Berlin/Boston 2021.
Miriam von Nordheim-Diehl Streit um Korach. Eine biblische Figur zwischen Numeri, den Psalmen und der Chronik (Wissenschaftliche Monographien zum Alten und Neuen Testament, Bd. 176), Vandenhoeck & Ruprecht, Göttingen 2023.
Stefan Alkier, Thomas Paulsen (Hg.): Das Evangelium nach Lukas und die Taten der Abgesandten. Neu übersetzt (Frankfurter Neues Testament Bd. 4), Brill, Schöningh, Paderborn 2023
Stefan Alkier (Hg.): Zuversichtsargumente. Biblische Perspektiven in Krisen und Ängsten unserer Zeit Biblische Argumente in öffentlichen Debatten Bd. 3 (in zwei Bänden)
Stefan Alkier, Martin Keßler und Stefan Rhein (Hg.): Evangelische Kirchen und Politik in Deutschland. Konstellationen im 20. Jahrhundert. (Christentum in der modernen Welt, Bd. 5), Mohr Siebeck, Tübingen 2023.
Stefan Michels: Testes veritatis. Studien zur transformativen Entwicklung des Wahrheitszeugenkonzepts in der Wittenberger Reformation. (SMHR, Bd. 129), Mohr Siebeck, Tübingen 2022.
Volker Leppin, Stefan Michels (Hg.): Reformation als Transformation? Interdisziplinäre Zugänge zum Transformationsparadigma als historiographischer Beschreibungskategorie. (SMHR, Bd. 126), Mohr Siebeck, Tübingen 2022.
Tugrul Kurt, Felix Machka, Johannes Müller, Christoph Rogers (Hg.): Grenzgänge wissenschaftlicher Reflexivität in Judentum, Christentum und Islam. Wissenschaftliche Buchgesellschaft, Darmstadt 2023.
Heiko Schulz, Jon Stewart, Karl Verstrynge (Hg.): Kierkegaard Studies Yearbook 2023. De Gruyter, Berlin/Boston 2023.
Heiko Schulz (Hg.): Das Böse – die Scham – das Opfer. Drei religiöse Kernphänomene in philosophisch-theologischer Perspektive. (Kleine Schriften des Fachbereichs Evangelische Theologie der Goethe-Universität Frankfurt am Main, Bd. 14), Evangelische Verlagsanstalt Leipzig 2023.
Harmjan Dam: Kirchengeschichte kompetenzorientiert unterrichten. Ein
Arbeitsbuch. Verlag W. Kohlhammer, Stuttgart 2023.
David Käbisch, Juliane Keitel (Hg.): Religion und Populismus. (Religion unterrichten, Bd. 2/2), Vandenhoeck & Ruprecht, Göttingen 2021.
Ann-Kathrin Knittel: Predigt und Exegese im Atelier. Kohlhammer, Stuttgart 2023.Walter Pohl, Andre Gingrich, Nathan P. Gibson (Hg.): Knowledge Collaboration among Jews, Christians, Zoroastrians, and Muslims in the Abbasid Near East I. Medieval Worlds 17 (2022), https://doi.org/10.1553/medievalworlds_no17_2022.
Walter Pohl, Andre Gingrich, Nathan P. Gibson (Hg.): Knowledge Collaboration among Jews, Christians, Zoroastrians, and Muslims in the Abbasid Near East II. Medieval Worlds 18 (July 2023),
https://doi.org/10.1553/medievalworlds_no18_2023.
Christian Wiese, Stefan Vogt, Mirjam Wenzel, Doron Kiesel, Gury SchneiderLudorff (Hg.): Das jüdische Frankfurt. Von der Emanzipation bis 1933. (Kontexte zur jüdischen Geschichte Hessens, Bd. 2), De Gruyter, Berlin / Boston 2023.
Claudio Carvalho, Ephraim Meir und Christian Wiese (Hg.): Rosenzweig Jahrbuch / Rosenzweig Yearbook 13: Transzendenz und Offenbarung / Transcendence and Revelation. Verlag Karl Alber, Freiburg i. Br. 2023.
Andrea Kirchner: Emissär der jüdischen Sache. Eine politische Biografie Richard Lichtheims. Instituts, Bd. 35), Vandenhoeck & Ruprecht, Göttingen 2023.
Andrea Kirchner (Hg.): Von Konstantinopel nach Genf. Quellen zum Wirken Richard Lichtheims. (Archiv jüdischer Geschichte und Kultur, Bd. 7), Vandenhoeck & Ruprecht, Göttingen 2022.
Measurements of the elliptic flow coefficient relative to the collision plane defined by the spectator neutrons v2{ΨSP} in collisions of Pb ions at center-of-mass energy per nucleon-nucleon pair sNN−−−√=2.76 TeV and Xe ions at sNN−−−√=5.44 TeV are reported. The results are presented for charged particles produced at midrapidity as a function of centrality and transverse momentum. The ratio between v2{ΨSP} and the elliptic flow coefficient relative to the participant plane v2{4}, estimated using four-particle correlations, deviates by up to 20% from unity depending on centrality. This observation differs strongly from the magnitude of the corresponding eccentricity ratios predicted by the TRENTo and the elliptic power models of initial state fluctuations that are tuned to describe the participant plane anisotropies. The differences can be interpreted as a decorrelation of the neutron spectator plane and the reaction plane because of fragmentation of the remnants from the colliding nuclei, which points to an incompleteness of current models of initial state fluctuations. A significant transverse momentum dependence of the ratio v2{ΨSP}/v2{4} is observed in all but the most central collisions, which may help to understand whether momentum anisotropies at low and intermediate transverse momentum have a common origin in initial state fluctuations. The ratios of v2{ΨSP} and v2{4} to the corresponding initial state eccentricities for Xe-Xe and Pb-Pb collisions at similar initial entropy density show a difference of (7.0±0.9)% with an additional variation of +1.8% when including RHIC data in the TRENTo parameter extraction. These observations provide new experimental constraints for viscous effects in the hydrodynamic modeling of the expanding quark-gluon plasma.
This article presents new measurements of the fragmentation properties of jets in both proton-proton (pp) and heavy-ion collisions with the ALICE experiment at the Large Hadron Collider (LHC). We report distributions of the fraction zr of transverse momentum carried by subjets of radius r within jets of radius R. Charged-particle jets are reconstructed at midrapidity using the anti-kT algorithm with jet radius R=0.4, and subjets are reconstructed by reclustering the jet constituents using the anti-kT algorithm with radii r=0.1 and r=0.2. In proton-proton collisions, we measure both the inclusive and leading subjet distributions. We compare these measurements to perturbative calculations at next-to-leading logarithmic accuracy, which suggest a large impact of threshold resummation and hadronization effects on the zr distribution. In heavy-ion collisions, we measure the leading subjet distributions, which allow access to a region of harder jet fragmentation than has been probed by previous measurements of jet quenching via hadron fragmentation distributions. The zr distributions enable extraction of the parton-to-subjet fragmentation function and allow for tests of the universality of jet fragmentation functions in the quark-gluon plasma (QGP). We find indications that there is a turnover in the ratio between the distributions in Pb-Pb and pp collisions as zr→1, exposing qualitatively new possibilities to disentangle competing jet quenching mechanisms. By comparing our results to theoretical calculations based on an independent extraction of the parton-to-jet fragmentation function, we find consistency with the universality of jet fragmentation and no indication of factorization breaking in the QGP.
Weimarer Beiträge 51/2005
(2005)
Die Weimarer Beiträge sind eine Zeitschrift für Literaturwissenschaft, aktuelle ästhetische Theorie und Kulturwissenschaft. Zu Ihren Schwerpunkten gehören moderne Literatur im Rahmen anderer Künste und Medien, die Wechselbeziehungen von Literatur, philosophischer und ästhetischer Reflexion sowie die kritische Analyse der Gegenwartskultur.
Weimarer Beiträge 67/2021
(2021)
Die Weimarer Beiträge sind eine Zeitschrift für Literaturwissenschaft, aktuelle ästhetische Theorie und Kulturwissenschaft. Zu Ihren Schwerpunkten gehören moderne Literatur im Rahmen anderer Künste und Medien, die Wechselbeziehungen von Literatur, philosophischer und ästhetischer Reflexion sowie die kritische Analyse der Gegenwartskultur.
Weimarer Beiträge 60/2014
(2014)
Die Weimarer Beiträge sind eine Zeitschrift für Literaturwissenschaft, aktuelle ästhetische Theorie und Kulturwissenschaft. Zu Ihren Schwerpunkten gehören moderne Literatur im Rahmen anderer Künste und Medien, die Wechselbeziehungen von Literatur, philosophischer und ästhetischer Reflexion sowie die kritische Analyse der Gegenwartskultur.
Weimarer Beiträge 65/2019
(2019)
Die Weimarer Beiträge sind eine Zeitschrift für Literaturwissenschaft, aktuelle ästhetische Theorie und Kulturwissenschaft. Zu Ihren Schwerpunkten gehören moderne Literatur im Rahmen anderer Künste und Medien, die Wechselbeziehungen von Literatur, philosophischer und ästhetischer Reflexion sowie die kritische Analyse der Gegenwartskultur.
Weimarer Beiträge 59/2013
(2013)
Die Weimarer Beiträge sind eine Zeitschrift für Literaturwissenschaft, aktuelle ästhetische Theorie und Kulturwissenschaft. Zu Ihren Schwerpunkten gehören moderne Literatur im Rahmen anderer Künste und Medien, die Wechselbeziehungen von Literatur, philosophischer und ästhetischer Reflexion sowie die kritische Analyse der Gegenwartskultur.
Weimarer Beiträge 52/2006
(2006)
Die Weimarer Beiträge sind eine Zeitschrift für Literaturwissenschaft, aktuelle ästhetische Theorie und Kulturwissenschaft. Zu Ihren Schwerpunkten gehören moderne Literatur im Rahmen anderer Künste und Medien, die Wechselbeziehungen von Literatur, philosophischer und ästhetischer Reflexion sowie die kritische Analyse der Gegenwartskultur.
Weimarer Beiträge 61/2015
(2015)
Die Weimarer Beiträge sind eine Zeitschrift für Literaturwissenschaft, aktuelle ästhetische Theorie und Kulturwissenschaft. Zu Ihren Schwerpunkten gehören moderne Literatur im Rahmen anderer Künste und Medien, die Wechselbeziehungen von Literatur, philosophischer und ästhetischer Reflexion sowie die kritische Analyse der Gegenwartskultur.
Weimarer Beiträge 62/2016
(2016)
Die Weimarer Beiträge sind eine Zeitschrift für Literaturwissenschaft, aktuelle ästhetische Theorie und Kulturwissenschaft. Zu Ihren Schwerpunkten gehören moderne Literatur im Rahmen anderer Künste und Medien, die Wechselbeziehungen von Literatur, philosophischer und ästhetischer Reflexion sowie die kritische Analyse der Gegenwartskultur.
The production yields of non-prompt Ds+ mesons, namely Ds+ mesons from beauty-hadron decays, were measured for the first time as a function of the transverse momentum (pT) at midrapidity (|y|<0.5) in central and semi-central Pb−Pb collisions at a centre-of-mass energy per nucleon pair sNN−−−√=5.02 TeV with the ALICE experiment at the LHC. The Ds+ mesons and their charge conjugates were reconstructed from the hadronic decay channel Ds+→ϕπ+, with ϕ→K−K+, in the 4<pT<36 GeV/c and 2<pT<24 GeV/c intervals for the 0−10% and 30−50% centrality classes, respectively. The measured yields of non-prompt Ds+ mesons are compared to those of prompt Ds+ and non-prompt D0 mesons by calculating the ratios of the production yields in Pb−Pb collisions and the nuclear modification factor RAA. The ratio between the RAA of non-prompt Ds+ and prompt Ds+ mesons, and that between the RAA of non-prompt Ds+ and non-prompt D0 mesons in central Pb−Pb collisions are found to be on average higher than unity in the 4<pT<12 GeV/c interval with a statistical significance of about 1.6σ and 1.7σ, respectively. The measured RAA ratios are compared with the predictions of theoretical models of heavy-quark transport in a hydrodynamically expanding QGP that incorporate hadronisation via quark recombination.
Charmonium production in pp collisions at center-of-mass energy of s√ = 13 TeV and p-Pb collisions at center-of-mass energy per nucleon pair of sNN−−−√ = 8.16 TeV is studied as a function of charged-particle pseudorapidity density with ALICE. Ground and excited charmonium states (J/ψ, ψ(2S)) are measured from their dimuon decays in the interval of rapidity in the center-of-mass frame 2.5<ycms<4.0 for pp collisions, and 2.03<ycms<3.53 and −4.46<ycms<−2.96 for p-Pb collisions. The charged-particle pseudorapidity density is measured around midrapidity (|η|<1.0). In pp collisions, the measured charged-particle multiplicity extends to about six times the average value, while in p-Pb collisions at forward (backward) rapidity a multiplicity corresponding to about three (four) times the average is reached. The ψ(2S) yield increases with the charged-particle pseudorapidity density. The ratio of ψ(2S) over J/ψ yield does not show a significant multiplicity dependence in either colliding system, suggesting a similar behavior of J/ψ and ψ(2S) yields with respect to charged-particle pseudorapidity density. The results are also compared with model calculations.
The first experimental information on the strong interaction between Λ and Ξ− strange baryons is presented in this Letter. The correlation function of Λ−Ξ− and Λ¯¯¯¯−Ξ¯¯¯¯+ pairs produced in high-multiplicity proton-proton (pp) collisions at s√ = 13 TeV at the LHC is measured as a function of the relative momentum of the pair. The femtoscopy method is used to calculate the correlation function, which is then compared with theoretical expectations obtained using a meson exchange model, chiral effective field theory, and Lattice QCD calculations close to the physical point. Data support predictions of small scattering parameters while discarding versions with large ones, thus suggesting a weak Λ−Ξ− interaction. The limited statistical significance of the data does not yet allow one to constrain the effects of coupled channels like Σ−Ξ and N−Ω.
Two-particle transverse momentum differential correlators, recently measured in Pb--Pb collisions at energies available at the CERN Large Hadron Collider (LHC), provide an additional tool to gain insights into particle production mechanisms and infer transport properties, such as the ratio of shear viscosity to entropy density, of the medium created in Pb-Pb collisions. The longitudinal long-range correlations and the large azimuthal anisotropy measured at low transverse momenta in small collision systems, namely pp and p-Pb, at LHC energies resemble manifestations of collective behaviour. This suggests that locally equilibrated matter may be produced in these small collision systems, similar to what is observed in Pb-Pb collisions. In this work, the same two-particle transverse momentum differential correlators are exploited in pp and p-Pb collisions at √s=7 TeV and sNN−−−√=5.02 TeV, respectively, to seek evidence for viscous effects. Specifically, the strength and shape of the correlators are studied as a function of the produced particle multiplicity to identify evidence for longitudinal broadening that might reveal the presence of viscous effects in these smaller systems. The measured correlators and their evolution from pp and p--Pb to Pb--Pb collisions are additionally compared to predictions from Monte Carlo event generators, and the potential presence of viscous effects is discussed.
Jet-like correlations with respect to K0S and Λ (Λ‾) in pp and Pb–Pb collisions at √sNN = 5.02 TeV
(2022)
Two-particle correlations with K0S, Λ/Λ¯, and charged hadrons as trigger particles in the transverse momentum range 8<pT,trig<16 GeV/c, and associated charged particles within 1<pT,assoc<8 GeV/c, are studied at mid-rapidity in pp and central Pb-Pb collisions at a centre-of-mass energy per nucleon-nucleon collision sNN−−−√=5.02 TeV with the ALICE detector at the LHC. After subtracting the contributions of the flow background, the per-trigger yields are extracted on both the near and away sides, and the ratio in Pb-Pb collisions with respect to pp collisions (IAA) is computed. The per-trigger yield in Pb-Pb collisions on the away side is strongly suppressed to the level of IAA≈0.6 for pT,assoc>3 GeV/c as expected from strong in-medium energy loss, while an enhancement develops at low pT,assoc on both the near and away sides, reaching IAA≈1.8 and 2.7 respectively. These findings are in good agreement with previous ALICE measurements from two-particle correlations triggered by neutral pions (π0-h) and charged hadrons (h-h) in Pb-Pb collisions at sNN−−−√=2.76 TeV. Moreover, the correlations with K0S mesons and Λ/Λ¯ baryons as trigger particles are compared to those of inclusive charged hadrons. The results are compared with the predictions of Monte Carlo models.
The measurement of the production of deuterons, tritons and 3He and their antiparticles in Pb-Pb collisions at sNN−−−√=5.02 TeV is presented in this article. The measurements are carried out at midrapidity (|y|< 0.5) as a function of collision centrality using the ALICE detector. The pT-integrated yields, the coalescence parameters and the ratios to protons and antiprotons are reported and compared with nucleosynthesis models. The comparison of these results in different collision systems at different centre-of-mass collision energies reveals a suppression of nucleus production in small systems. In the Statistical Hadronisation Model framework, this can be explained by a small correlation volume where the baryon number is conserved, as already shown in previous fluctuation analyses. However, a different size of the correlation volume is required to describe the proton yields in the same data sets. The coalescence model can describe this suppression by the fact that the wave functions of the nuclei are large and the fireball size starts to become comparable and even much smaller than the actual nucleus at low multiplicities.
The pseudorapidity density of charged particles with minimum transverse momentum (pT) thresholds of 0.15, 0.5, 1, and 2 GeV/c was measured in pp collisions at centre-of-mass energies of √s = 5.02 and 13 TeV with the ALICE detector. The study is carried out for inelastic collisions with at least one primary charged particle having a pseudorapidity (η) within ±0.8 and pT larger than the corresponding threshold. The measurements were also performed for inelastic and non-single-diffractive events as well as for inelastic events with at least one charged particle having |η| < 1 in pp collisions at √s = 5.02 TeV for the first time at the LHC. The measurements are compared to the PYTHIA 6, PYTHIA 8, and EPOS-LHC models. In general, the models describe the pseudorapidity dependence of particle production well, however, discrepancies are observed for event classes including diffractive events and for the highest transverse momentum threshold (pT > 2 GeV/c), highlighting the importance of such measurements for tuning event generators. The new measurements agree within uncertainties with results from the ATLAS and CMS experiments.
First measurement of 𝚲+c production down to 𝑝T = 0 in pp and p–Pb collisions at √𝑠NN = 5.02 TeV
(2023)
The production of prompt Λ+c baryons has been measured at midrapidity in the transverse momentum interval 0<pT<1 GeV/c for the first time, in pp and p-Pb collisions at a centre-of-mass energy per nucleon-nucleon collision sNN−−−√=5.02 TeV. The measurement was performed in the decay channel Λ+c→pK0S by applying new decay reconstruction techniques using a Kalman-Filter vertexing algorithm and adopting a machine-learning approach for the candidate selection. The pT-integrated Λ+c production cross sections in both collision systems were determined and used along with the measured yields in Pb-Pb collisions to compute the pT-integrated nuclear modification factors RpPb and RAA of Λ+c baryons, which are compared to model calculations that consider nuclear modification of the parton distribution functions. The Λ+c/D0 baryon-to-meson yield ratio is reported for pp and p-Pb collisions. Comparisons with models that include modified hadronisation processes are presented, and the implications of the results on the understanding of charm hadronisation in hadronic collisions are discussed. A significant (3.7σ) modification of the mean transverse momentum of Λ+c baryons is seen in p-Pb collisions with respect to pp collisions, while the pT-integrated Λ+c/D0 yield ratio was found to be consistent between the two collision systems within the uncertainties.
The first measurement of event-by-event antideuteron number fluctuations in high energy heavy-ion collisions is presented. The measurements are carried out at midrapidity (|η|<0.8) as a function of collision centrality in Pb−Pb collisions at sNN−−−√=5.02 TeV using the ALICE detector. A significant negative correlation between the produced antiprotons and antideuterons is observed in all collision centralities. The results are compared with coalescence calculations, which fail to describe the measurement, in particular if a correlated production of protons and neutrons is assumed. Thermal-statistical model calculations describe the data within uncertainties only for correlation volumes that are different with respect to those describing proton yields and a similar measurement of net-proton number fluctuations.
The transverse-momentum (pT) spectra of K∗(892)0 and ϕ(1020) measured with the ALICE detector up to pT = 16 GeV/c in the rapidity range −1.2<y<0.3, in p-Pb collisions at center-of-mass energy per nucleon-nucleon collision sNN−−−√ = 5.02 TeV are presented as a function of charged particle multiplicity and rapidity. The measured pT distributions show a dependence on both multiplicity and rapidity at low pT whereas no significant dependence is observed at high pT. A rapidity dependence is observed in the pT-integrated yield (dN/dy), whereas the mean transverse momentum (⟨pT⟩) shows a flat behavior as a function of rapidity. The rapidity asymmetry (Yasym) at low pT ( < 5 GeV/c) is more significant for higher multiplicity classes. At high pT, no significant rapidity asymmetry is observed in none of the multiplicity classes. Both K∗(892)0 and ϕ(1020) show similar Yasym. The nuclear modification factor (QCP) as a function of pT shows a Cronin-like enhancement at intermediate pT, which is more prominent at higher rapidities (Pb-going direction) and in higher multiplicity classes. At high pT (> 5 GeV/c), the QCP values are greater than unity and no significant rapidity dependence is observed.
Measurement of the J/ψ polarization with respect to the event plane in Pb–Pb collisions at the LHC
(2022)
The polarization of inclusive J/ψ produced in Pb-Pb collisions at sNN−−−√=5.02 TeV at the LHC was studied by ALICE in the dimuon channel, via the measurement of the angular distribution of its decay products. The study was performed in the rapidity region 2.5<y<4, for three transverse momentum intervals (2<pT<4, 4<pT<6, 6<pT<10 GeV/c) and as a function of the centrality of the collision for 2<pT<6 GeV/c. For the first time, the polarization was measured with respect to the event plane of the collision, by considering the angle between the positive-charge decay muon in the J/ψ rest frame and the axis perpendicular to the event-plane vector in the laboratory system. A small transverse polarization is measured, with a significance reaching 3.9σ at low pT and for intermediate centrality values. The polarization could be connected with the existence of a strong magnetic field in the early stage of quark-gluon plasma formation in Pb-Pb collisions, as well as with its behaviour as a rotating fluid with large vorticity.
Investigation of K+K− interactions via femtoscopy in Pb−Pb collisions at √sNN = 2.76 TeV at the LHC
(2022)
Femtoscopic correlations of non-identical charged kaons (K+K−) are studied in Pb−Pb collisions at a center-of-mass energy per nucleon−nucleon collision sNN−−−√=2.76 TeV by ALICE at the LHC. One-dimensional K+K− correlation functions are analyzed in three centrality classes and eight intervals of particle-pair transverse momentum. The Lednický and Luboshitz interaction model used in the K+K− analysis includes the final-state Coulomb interactions between kaons and the final-state interaction through a0(980) and f0(980) resonances. The mass of f0(980) and coupling were extracted from the fit to K+K− correlation functions using the femtoscopic technique for the first time. The measured mass and width of the f0(980) resonance are consistent with other published measurements. The height of the ϕ(1020) meson peak present in the K+K− correlation function rapidly decreases with increasing source radius, qualitatively in agreement with an inverse volume dependence. A phenomenological fit to this trend suggests that the ϕ(1020) meson yield is dominated by particles produced directly from the hadronization of the system. The small fraction subsequently produced by FSI could not be precisely quantified with data presented in this paper and will be assessed in future work.
This article reports measurements of the angle between differently defined jet axes in pp collisions at s√=5.02 TeV carried out by the ALICE Collaboration. Charged particles at midrapidity are clustered into jets with resolution parameters R=0.2 and 0.4. The jet axis, before and after Soft Drop grooming, is compared to the jet axis from the Winner-Takes-All (WTA) recombination scheme. The angle between these axes, ΔRaxis, probes a wide phase space of the jet formation and evolution, ranging from the initial high-momentum-transfer scattering to the hadronization process. The ΔRaxis observable is presented for 20<pchjetT<100 GeV/c, and compared to predictions from the PYTHIA 8 and Herwig 7 event generators. The distributions can also be calculated analytically with a leading hadronization correction related to the non-perturbative component of the Collins−Soper−Sterman (CSS) evolution kernel. Comparisons to analytical predictions at next-to-leading-logarithmic accuracy with leading hadronization correction implemented from experimental extractions of the CSS kernel in Drell−Yan measurements are presented. The analytical predictions describe the measured data within 20% in the perturbative regime, with surprising agreement in the non-perturbative regime as well. These results are compatible with the universality of the CSS kernel in the context of jet substructure.
This letter reports measurements which characterize the underlying event associated with hard scatterings at mid-pseudorapidity (|η|<0.8) in pp, p−Pb and Pb−Pb collisions at centre-of-mass energy per nucleon pair, sNN−−−√=5.02 TeV. The measurements are performed with ALICE at the LHC. Different multiplicity classes are defined based on the event activity measured at forward rapidities. The hard scatterings are identified by the leading particle defined as the charged particle with the largest transverse momentum (pT) in the collision and having 8<pT<15 GeV/c. The pT spectra of associated particles (0.5≤pT<6 GeV/c) are measured in different azimuthal regions defined with respect to the leading particle direction: toward, transverse, and away. The associated charged particle yields in the transverse region are subtracted from those of the away and toward regions. The remaining jet-like yields are reported as a function of the multiplicity measured in the transverse region. The measurements show a suppression of the jet-like yield in the away region and an enhancement of high-pT associated particles in the toward region in central Pb−Pb collisions, as compared to minimum-bias pp collisions. These observations are consistent with previous measurements that used two-particle correlations, and with an interpretation in terms of parton energy loss in a high-density quark gluon plasma. These yield modifications vanish in peripheral Pb−Pb collisions and are not observed in either high-multiplicity pp or p−Pb collisions.
This article presents measurements of the groomed jet radius and momentum splitting fraction in pp collisions at s√=5.02 TeV with the ALICE detector at the Large Hadron Collider. Inclusive charged-particle jets are reconstructed at midrapidity using the anti-kT algorithm for transverse momentum 60<pchjetT<80 GeV/c. We report results using two different grooming algorithms: soft drop and, for the first time, dynamical grooming. For each grooming algorithm, a variety of grooming settings are used in order to explore the impact of collinear radiation on these jet substructure observables. These results are compared to perturbative calculations that include resummation of large logarithms at all orders in the strong coupling constant. We find good agreement of the theoretical predictions with the data for all grooming settings considered.
We present the first systematic comparison of the charged-particle pseudorapidity densities for three widely different collision systems, pp, p-Pb, and Pb-Pb, at the top energy of the Large Hadron Collider (sNN−−−√=5.02 TeV) measured over a wide pseudorapidity range (−3.5<η<5), the widest possible among the four experiments at that facility. The systematic uncertainties are minimised since the measurements are recorded by the same experimental apparatus (ALICE). The distributions for p-Pb and Pb-Pb collisions are determined as a function of the centrality of the collisions, while results from pp collisions are reported for inelastic events with at least one charged particle at midrapidity. The charged-particle pseudorapidity densities are, under simple and robust assumptions, transformed to charged-particle rapidity densities. This allows for the calculation and the presentation of the evolution of the width of the rapidity distributions and of a lower bound on the Bjorken energy density, as a function of the number of participants in all three collision systems. We find a decreasing width of the particle production, and roughly a smooth ten fold increase in the energy density, as the system size grows, which is consistent with a gradually higher dense phase of matter.
The inclusive production of the charm-strange baryon Ω0c is measured for the first time via its hadronic decay into Ω−π+ at midrapidity (|y|<0.5) in proton-proton (pp) collisions at the centre-of-mass energy s√=13 TeV with the ALICE detector at the LHC. The transverse momentum (pT) differential cross section multiplied by the branching ratio is presented in the interval 2<pT<12 GeV/c. The pT dependence of the Ω0c-baryon production relative to the prompt D0-meson and to the prompt Ξ0c-baryon production is compared to various models that take different hadronisation mechanisms into consideration. In the measured pT interval, the ratio of the pT-integrated cross sections of Ω0c and prompt Λ+c baryons multiplied by the Ω−π+ branching ratio is found to be larger by a factor of about 20 with a significance of about 4σ when compared to e+e− collisions.
Hadronic resonances are used to probe the hadron gas produced in the late stage of heavy-ion collisions since they decay on the same timescale, of the order of 1 to 10 fm/c, as the decoupling time of the system. In the hadron gas, (pseudo)elastic scatterings among the products of resonances that decayed before the kinetic freeze-out and regeneration processes counteract each other, the net effect depending on the resonance lifetime, the duration of the hadronic phase, and the hadronic cross sections at play. In this context, the Σ(1385)± particle is of particular interest as models predict that regeneration dominates over rescattering despite its relatively short lifetime of about 5.5 fm/c. The first measurement of the Σ(1385)± resonance production at midrapidity in Pb-Pb collisions at sNN−−−√=5.02 TeV with the ALICE detector is presented in this Letter. The resonances are reconstructed via their hadronic decay channel, Λπ, as a function of the transverse momentum (pT) and the collision centrality. The results are discussed in comparison with the measured yield of pions and with expectations from the statistical hadronization model as well as commonly employed event generators, including PYTHIA8/Angantyr and EPOS3 coupled to the UrQMD hadronic cascade afterburner. None of the models can describe the data. For Σ(1385)±, a similar behaviour as K∗(892)0 is observed in data unlike the predictions of EPOS3 with afterburner.
This Letter reports on the first measurements of transverse momentum dependent flow angle Ψn and flow magnitude vn fluctuations, determined using new four-particle correlators. The measurements are performed for various centralities in Pb-Pb collisions at a centre-of-mass energy per nucleon pair of sNN−−−√ = 5.02 TeV with ALICE at the CERN Large Hadron Collider. Both flow angle and flow magnitude fluctuations are observed in the presented centrality ranges and are strongest in the most central collisions and for a transverse momentum pT>2 GeV/c. Comparison with theoretical models, including iEBE-VISHNU, MUSIC, and AMPT, show that the measurements exhibit unique sensitivities to the initial state of heavy-ion collisions.
Three-body nuclear forces play an important role in the structure of nuclei and hypernuclei and are also incorporated in models to describe the dynamics of dense baryonic matter, such as in neutron stars. So far, only indirect measurements anchored to the binding energies of nuclei can be used to constrain the three-nucleon force, and if hyperons are considered, the scarce data on hypernuclei impose only weak constraints on the three-body forces. In this work, we present the first direct measurement of the p−p−p and p−p−Λ systems in terms of three-particle mixed moments carried out for pp collisions at s√ = 13 TeV. Three-particle cumulants are extracted from the normalised mixed moments by applying the Kubo formalism, where the three-particle interaction contribution to these moments can be isolated after subtracting the known two-body interaction terms. A negative cumulant is found for the p−p−p system, hinting to the presence of a residual three-body effect while for p−p−Λ the cumulant is consistent with zero. This measurement demonstrates the accessibility of three-baryon correlations at the LHC.
Fluctuation measurements are important sources of information on the mechanism of particle production at LHC energies. This article reports the first experimental results on third-order cumulants of the net-proton distributions in Pb−Pb collisions at a center-of-mass energy sNN−−−√=5.02 TeV recorded by the ALICE detector. The results on the second-order cumulants of net-proton distributions at sNN−−−√=2.76 and 5.02 TeV are also discussed in view of effects due to the global and local baryon number conservation. The results demonstrate the presence of long-range rapidity correlations between protons and antiprotons. Such correlations originate from the early phase of the collision. The experimental results are compared with HIJING and EPOS model calculations, and the dependence of the fluctuation measurements on the phase-space coverage is examined in the context of lattice quantum chromodynamics (LQCD) and hadron resonance gas (HRG) model estimations. The measured third-order cumulants are consistent with zero within experimental uncertainties of about 4% and are described well by LQCD and HRG predictions.
The interaction of K− with protons is characterised by the presence of several coupled channels, systems like K¯¯¯¯0n and πΣ with a similar mass and the same quantum numbers as the K−p state. The strengths of these couplings to the K−p system are of crucial importance for the understanding of the nature of the Λ(1405) resonance and of the attractive K−p strong interaction. In this article, we present measurements of the K−p correlation functions in relative momentum space obtained in pp collisions at s√ = 13 TeV, in p-Pb collisions at sNN−−−√ = 5.02 TeV, and (semi)peripheral Pb-Pb collisions at sNN−−−√ = 5.02 TeV. The emitting source size, composed of a core radius anchored to the K+p correlation and of a resonance halo specific to each particle pair, varies between 1 and 2 fm in these collision systems. The strength and the effects of the K¯¯¯¯0n and πΣ inelastic channels on the measured K−p correlation function are investigated in the different colliding systems by comparing the data with state-of-the-art models of chiral potentials. A novel approach to determine the conversion weights ω, necessary to quantify the amount of produced inelastic channels in the correlation function, is presented. In this method, particle yields are estimated from thermal model predictions, and their kinematic distribution from blast-wave fits to measured data. The comparison of chiral potentials to the measured K−p interaction indicates that, while the πΣ−K−p dynamics is well reproduced by the model, the coupling to the K¯¯¯¯0n channel in the model is currently underestimated.
The measurement of the production of f0(980) in inelastic pp collisions at s√=5.02 TeV is presented. This is the first reported measurement of inclusive f0(980) production at LHC energies. The production is measured at midrapidity, |y|<0.5, in a wide transverse momentum range, 0<pT<16 GeV/c, by reconstructing the resonance in the f0(980)→π+π− hadronic decay channel using the ALICE detector. The pT-differential yields are compared to those of pions, protons and ϕ mesons as well as to predictions from the HERWIG 7.2 QCD-inspired Monte Carlo event generator and calculations from a coalescence model that uses the AMPT model as an input. The ratio of the pT-integrated yield of f0(980) relative to pions is compared to measurements in e+e− and pp collisions at lower energies and predictions from statistical hadronisation models and HERWIG 7.2. A mild collision energy dependence of the f0(980) to pion production is observed in pp collisions from SPS to LHC energies. All considered models underpredict the pT-integrated f0(980)/(π++π−) ratio. The prediction from the γs-CSM model assuming a zero total strangeness content of f0(980) is consistent with the data within 1.9σ and is the closest to the data. The results provide an essential reference for future measurements of the particle yield and nuclear modification in p−Pb and Pb−Pb collisions, which have been proposed to be instrumental to probe the elusive nature and quark composition of the f0(980) scalar meson.
Anisotropic flow and flow fluctuations of identified hadrons in Pb–Pb collisions at √sNN = 5.02 TeV
(2022)
The first measurements of elliptic flow of π±, K±, p+p¯¯¯, K0S, Λ+Λ¯¯¯¯, ϕ, Ξ−+Ξ+, and Ω−+Ω+ using multiparticle cumulants in Pb−Pb collisions at sNN−−−√ = 5.02 TeV are presented. Results obtained with two- (v2{2}) and four-particle cumulants (v2{4}) are shown as a function of transverse momentum, pT, for various collision centrality intervals. Combining the data for both v2{2} and v2{4} also allows us to report the first measurements of the mean elliptic flow, elliptic flow fluctuations, and relative elliptic flow fluctuations for various hadron species. These observables probe the event-by-event eccentricity fluctuations in the initial state and the contributions from the dynamic evolution of the expanding quark-gluon plasma. The characteristic features observed in previous pT-differential anisotropic flow measurements for identified hadrons with two-particle correlations, namely the mass ordering at low pT and the approximate scaling with the number of constituent quarks at intermediate pT, are similarly present in the four-particle correlations and the combinations of v2{2} and v2{4}. In addition, a particle species dependence of flow fluctuations is observed that could indicate a significant contribution from final state hadronic interactions. The comparison between experimental measurements and CoLBT model calculations, which combine the various physics processes of hydrodynamics, quark coalescence, and jet fragmentation, illustrates their importance over a wide pT range.
The study of the azimuthal anisotropy of inclusive muons produced in p-Pb collisions at sNN−−−√=8.16 TeV, using the ALICE detector at the LHC is reported. The measurement of the second-order Fourier coefficient of the particle azimuthal distribution, v2, is performed as a function of transverse momentum pT in the 0-20% high-multiplicity interval at both forward (2.03<yCMS<3.53) and backward (−4.46<yCMS<−2.96) rapidities over a wide pT range, 0.5<pT<10 GeV/c, in which a dominant contribution of muons from heavy-flavour hadron decays is expected at pT>2 GeV/c. The v2 coefficient of inclusive muons is extracted using two different techniques, namely two-particle cumulants, used for the first time for heavy-flavour measurements, and forward-central two-particle correlations. Both techniques give compatible results. A positive v2 is measured at both forward and backward rapidities with a significance larger than 4.7σ and 7.6σ, respectively, in the interval 2<pT<6 GeV/c. Comparisons with previous measurements in p-Pb collisions at sNN−−−√=5.02 TeV, and with AMPT and CGC-based theoretical calculations are discussed. The findings impose new constraints on the theoretical interpretations of the origin of the collective behaviour in small collision systems.
The study of the azimuthal anisotropy of inclusive muons produced in p-Pb collisions at sNN−−−√=8.16 TeV, using the ALICE detector at the LHC is reported. The measurement of the second-order Fourier coefficient of the particle azimuthal distribution, v2, is performed as a function of transverse momentum pT in the 0-20% high-multiplicity interval at both forward (2.03<yCMS<3.53) and backward (−4.46<yCMS<−2.96) rapidities over a wide pT range, 0.5<pT<10 GeV/c, in which a dominant contribution of muons from heavy-flavour hadron decays is expected at pT>2 GeV/c. The v2 coefficient of inclusive muons is extracted using two different techniques, namely two-particle cumulants, used for the first time for heavy-flavour measurements, and forward-central two-particle correlations. Both techniques give compatible results. A positive v2 is measured at both forward and backward rapidities with a significance larger than 4.7σ and 7.6σ, respectively, in the interval 2<pT<6 GeV/c. Comparisons with previous measurements in p-Pb collisions at sNN−−−√=5.02 TeV, and with AMPT and CGC-based theoretical calculations are discussed. The findings impose new constraints on the theoretical interpretations of the origin of the collective behaviour in small collision systems.
In ultraperipheral collisions (UPCs) of relativistic nuclei without overlap of nuclear densities, the two nuclei are excited by the Lorentz-contracted Coulomb fields of their collision partners. In these UPCs, the typical nuclear excitation energy is below a few tens of MeV, and a small number of nucleons are emitted in electromagnetic dissociation (EMD) of primary nuclei, in contrast to complete nuclear fragmentation in hadronic interactions. The cross sections of emission of given numbers of neutrons in UPCs of 208Pb nuclei at sNN−−−√=5.02 TeV were measured with the neutron zero degree calorimeters (ZDCs) of the ALICE detector at the LHC, exploiting a similar technique to that used in previous studies performed at sNN−−−√=2.76 TeV. In addition, the cross sections for the exclusive emission of one, two, three, four, and five forward neutrons in the EMD, not accompanied by the emission of forward protons, and thus mostly corresponding to the production of 207,206,205,204,203Pb, respectively, were measured for the first time. The predictions from the available models describe the measured cross sections well. These cross sections can be used for evaluating the impact of secondary nuclei on the LHC components, in particular, on superconducting magnets, and also provide useful input for the design of the Future Circular Collider (FCC-hh).
Eritrean refugees crisscross between countries in the Horn of Africa and North Africa in search of a safe place. Along their journeys, they are looted, threatened, intimidated, violated, and held for ransom. This book revisits the human trafficking crisis that first emerged in the Sinai at the end of 2008 and examines the expansion of human trafficking of Eritrean refugees and other forms of exploitation beyond the Sinai. It focuses on the modus operandi of these practices and on identifying their key facilitators and beneficiaries. The book locates the origin of these practices within Eritrea; it reveals how a deliberate policy of impoverishment and human rights abuses has driven the people out of the country, and how individuals within Eritrea, and particularly within the ruling party, benefit from the smuggling and trafficking of Eritrean refugees. The use of information communication technologies (ICTs) is identified as key to the new modus operandi of this criminal business and is found to further facilitate widespread collective trauma amongst Eritreans, who witness the abuse of their family members and fellow nationals through digital networks. An entire section in this book is dedicated to assessing the extent and effects of individual and collective trauma caused by Sinai trafficking and to examining potential approaches to healing. Other sections discuss the vulnerabilities of Eritrean minors and women, and the connections between human trafficking, terrorism and organ trafficking. The last section of the book raises the question of accountability. It examines and evaluates international responses to this forgotten crisis, and discusses the need for policies that tackle the problem where it emerges: in Eritrea.
W±-boson production in p–Pb collisions at √sNN = 8.16 TeV and Pb–Pb collisions at √sNN = 5.02 TeV
(2022)
The production of the W± bosons measured in p−Pb collisions at a centre-of-mass energy per nucleon−nucleon collision sNN−−−−√=8.16 TeV and Pb−Pb collisions at sNN−−−−√=5.02 TeV with ALICE at the LHC is presented. The W± bosons are measured via their muonic decay channel, with the muon reconstructed in the pseudorapidity region −4<ημlab<−2.5 with transverse momentum pμT>10 GeV/c. While in Pb−Pb collisions the measurements are performed in the forward (2.5<yμcms<4) rapidity region, in p−Pb collisions, where the centre-of-mass frame is boosted with respect to the laboratory frame, the measurements are performed in the backward (−4.46<yμcms<−2.96) and forward (2.03<yμcms<3.53) rapidity regions. The W− and W+ production cross sections, lepton-charge asymmetry, and nuclear modification factors are evaluated as a function of the muon rapidity. In order to study the production as a function of the p−Pb collision centrality, the production cross sections of the W− and W+ bosons are combined and normalised to the average number of binary nucleon−nucleon collision ⟨Ncoll⟩. In Pb−Pb collisions, the same measurements are presented as a function of the collision centrality. Study of the binary scaling of the W±-boson cross sections in p−Pb and Pb−Pb collisions is also reported. The results are compared with perturbative QCD (pQCD) calculations, with and without nuclear modifications of the Parton Distribution Functions (PDFs), as well as with available data at the LHC. Significant deviations from the theory expectations are found in the two collision systems, indicating that the measurements can provide additional constraints for the determination of nuclear PDF (nPDFs) and in particular of the light-quark distributions.