The azimuthal anisotropy of charged particles in Pb-Pb collisions at sqrt[s(NN)]=2.76 TeV is measured with the CMS detector at the LHC over an extended transverse momentum (p(T)) range up to approximately 60 GeV/c. The data cover both the low-p(T) region associated with hydrodynamic flow phenomena and the high-p(T) region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60% most-central events, the observed v2 values are found to first increase with p(T), reaching a maximum around p(T)=3 GeV/c, and then to gradually decrease to almost zero, with the decline persisting up to at least pp(T)=40 GeV/c over the full centrality range measured.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevLett.109.022301 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Thin Films of BaM Hexaferrite with an Inclined Orientation of the Easy Magnetization Axis: Crystal Structure and Magnetic Properties.
Nanomaterials (Basel)
November 2024
Ioffe Institute, Politechnicheskaya 26, 194021 St. Petersburg, Russia.
Thin (~50 nm thick) BaM hexaferrite (BaFeO) films were grown on (1-102) and (0001) cut α-AlO (sapphire) substrates via laser molecular beam epitaxy using a one- or two-stage growth protocol. The advantages of a two-stage protocol are shown. The surface morphology, structural and magnetic properties of films were studied using atomic force microscopy, reflected high-energy electron diffraction, three-dimensional X-ray diffraction reciprocal space mapping, powder X-ray diffraction, magneto-optical, and magnetometric methods.
View Article and Find Full Text PDFHadron-ion collisions in Pythia and the vector-meson dominance model for photoproduction.
Eur Phys J C Part Fields
November 2024
Department of Physics, University of Jyvaskyla, P.O. Box 35, Fl-40014 Jyvaskyla, Finland.
Article Synopsis
- The extension of the Pythia Monte Carlo event generator allows for detailed simulations of collisions between a hadron beam and nuclear targets, with energy variations for each event.
- The work builds on existing models like Angantyr for heavy ions and includes a vector-meson dominance (VMD) model for simulating real photon interactions in photo-nuclear collisions.
- Validation with HERA data shows the model's effectiveness, and the generated events for ultra-peripheral heavy-ion collisions at the LHC align with ATLAS measurements, demonstrating consistency in single-particle multiplicity and azimuthal anisotropy patterns.
Intrinsic Magnetocrystalline Anisotropy Induced 3m-Symmetry Dependent Field-Free Switching in Epitaxial Garnet Films.
Phys Rev Lett
November 2024
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
The electrical control of perpendicular magnetization without the need for external magnetic fields holds significant potential for next-generation spintronic devices. In this Letter, we have identified a 3m-symmetry dependent field-free switching phenomenon in (111)-oriented Tm_{3}Fe_{5}O_{12} single-crystal films capped with a platinum (Pt) layer. We demonstrate that this distinctive property arises due to the spontaneous breaking of mirror symmetry in magnetocrystalline anisotropy (MCA) for (111)-oriented magnetic films with a cubic structure, which results in a local out-of-plane MCA effective field with a 3m-symmetry dependence on the azimuth angle when the magnetization lies in the (111) plane.
View Article and Find Full Text PDFQuantitative characterization of optical anisotropies is extremely important for wide fields and applications. The Mueller matrix, providing all the polarization-related properties of a medium, is a powerful tool for the comprehensive evaluation of optical anisotropies. Here, we propose a ptychographic Mueller matrix imaging (PMMI) technique, which features the Mueller matrix polarization modulation being introduced into the ptychography.
View Article and Find Full Text PDFExtracting the Heterogeneous 3D Structure of Molecular Films Using Higher Dimensional SFG Microscopy.
J Phys Chem Lett
October 2024
Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, Berlin 14195, Germany.
Ultrathin molecular films are widespread in both natural and industrial settings, where details of the molecular structure such as density, out-of-plane tilt angles, and in-plane directionality determine their physicochemical properties. Many of these films possess important molecular-to-macroscopic heterogeneity in these structural parameters, which have traditionally been difficult to characterize. Here, we show how extending sum-frequency generation (SFG) microscopy measurements to higher dimensionality by azimuthal-scanning can extract the spatial variation in the three-dimensional molecular structure at an interface.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!