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Measurements of jet quenching using semi-inclusive hadron+jet distributions in pp and central Pb-Pb collisions at sNN=5.02 TeV

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Physical Review C 2024年第1期110卷 014906-014906页

作者： S. Acharya D. Adamová G. Aglieri Rinella M. Agnello N. Agrawal Z. Ahammed S. Ahmad S. U. Ahn I. Ahuja A. Akindinov M. Al-Turany D. Aleksandrov B. Alessandro H. M. Alfanda R. Alfaro Molina B. Ali A. Alici N. Alizadehvandchali A. Alkin J. Alme G. Alocco T. Alt A. R. Altamura I. Altsybeev J. R. Alvarado M. N. Anaam C. Andrei N. Andreou A. Andronic V. Anguelov F. Antinori P. Antonioli N. Apadula L. Aphecetche H. Appelshäuser C. Arata S. Arcelli M. Aresti R. Arnaldi J. G. M. C. A. Arneiro I. C. Arsene M. Arslandok A. Augustinus R. Averbeck M. D. Azmi H. Baba A. Badalà J. Bae Y. W. Baek X. Bai R. Bailhache Y. Bailung A. Balbino A. Baldisseri B. Balis D. Banerjee Z. Banoo R. Barbera F. Barile L. Barioglio M. Barlou B. Barman G. G. Barnaföldi L. S. Barnby V. Barret L. Barreto C. Bartels K. Barth E. Bartsch N. Bastid S. Basu G. Batigne D. Battistini B. Batyunya D. Bauri J. L. Bazo Alba I. G. Bearden C. Beattie P. Becht D. Behera I. Belikov A. D. C. Bell Hechavarria F. Bellini R. Bellwied S. Belokurova Y. A. V. Beltran G. Bencedi S. Beole Y. Berdnikov A. Berdnikova L. Bergmann M. G. Besoiu L. Betev P. P. Bhaduri A. Bhasin M. A. Bhat B. Bhattacharjee L. Bianchi N. Bianchi J. Bielčík J. Bielčíková J. Biernat A. P. Bigot A. Bilandzic G. Biro S. Biswas N. Bize J. T. Blair D. Blau M. B. Blidaru N. Bluhme C. Blume G. Boca F. Bock T. Bodova A. Bogdanov S. Boi J. Bok L. Boldizsár M. Bombara P. M. Bond G. Bonomi H. Borel A. Borissov A. G. Borquez Carcamo H. Bossi E. Botta Y. E. M. Bouziani L. Bratrud P. Braun-Munzinger M. Bregant M. Broz G. E. Bruno M. D. Buckland D. Budnikov H. Buesching S. Bufalino P. Buhler N. Burmasov Z. Buthelezi A. Bylinkin S. A. Bysiak M. Cai H. Caines A. Caliva E. Calvo Villar J. M. M. Camacho P. Camerini F. D. M. Canedo S. L. Cantway M. Carabas A. A. Carballo F. Carnesecchi R. Caron L. A. D. Carvalho J. Castillo Castellanos F. Catalano C. Ceballos Sanchez I. Chakaberia P. Chakraborty S. Chandra S. Chapeland M. Chartier S. Chattopadhyay T. Cheng C. Cheshkov B. Cheynis V. Chibante Barroso D. D. Chinellato E. CNRS/IN2P3 LPC Clermont-Ferrand France Nuclear Physics Institute of the Czech Academy of Sciences Husinec-Řež Czech Republic Geneva Switzerland Turin Italy Bologna Italy Homi Bhabha National Institute Kolkata India Department of Physics Daejeon Republic of Korea Faculty of Science Affiliated with an institute covered by a cooperation agreement with CERN Research Division and ExtreMe Matter Institute EMMI Wuhan China Instituto de Física and Sezione INFN Bologna Italy Houston Texas USA Department of Physics and Technology Cagliari Italy Institut für Kernphysik Bari Italy Physik Department Technische Universität München Munich Germany High Energy Physics Group Bucharest Romania University of Derby Derby United Kingdom Institut für Kernphysik Münster Germany Physikalisches Institut Padova Italy Berkeley California USA SUBATECH IMT Atlantique Université Grenoble-Alpes CNRS-IN2P3 Grenoble France and Sezione INFN Cagliari Italy São Paulo Brazil New Haven Connecticut USA Tokyo Japan Catania Italy Sungkyunkwan University Suwon City Republic of Korea Gangneung Republic of Korea Hefei China Indore India Université Paris-Saclay Centre d'Etudes de Saclay (CEA) IRFU Départment de Physique Nucléaire (DPhN) Saclay France Cracow Poland Department of Physics and Centre for Astroparticle Physics and Space Science (CAPSS) Kolkata India Physics Department and Sezione INFN Catania Italy and Sezione INFN Bari Italy School of Science Department of Physics Athens Greece Department of Physics Guwahati India Budapest Hungary Nuclear Physics Group STFC Liverpool United Kingdom Department of Physics Division of Particle Physics Lund Sweden Affiliated with an international laboratory covered by a cooperation agreement with CERN Mumbai India Sección Física Departamento de Ciencias Niels Bohr Institute CNRS IPHC UMR 7178 F-67000 Strasbourg France Strasbourg France and Sezione INFN Turin Italy INFN

The ALICE Collaboration reports measurements of the semi-inclusive distribution of charged-particle jets recoiling from a high transverse momentum (high pT) charged hadron, in pp and central Pb-Pb collisions at center-of-mass energy per nucleon–nucleon collision sNN=5.02 TeV. The large uncorrelated background in central Pb-Pb collisions is corrected using a data-driven statistical approach which enables precise measurement of recoil jet distributions over a broad range in pT,chjet and jet resolution parameter R. Recoil jet yields are reported for R=0.2, 0.4, and 0.5 in the range 7

关键词： Jet quenching Quark & gluon jets Quark-gluon plasma Relativistic heavy-ion collisions Strong interaction

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Circular Polarization of Simulated Images of Black Holes

arXiv

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arXiv 2024年

作者： Joshi, Abhishek V. Prather, Ben S. Chan, Chi-Kwan Wielgus, Maciek Gammie, Charles F. Department of Physics University of Illinois 1110 West Green Street UrbanaIL61801 United States Illinois Center for Advanced Study of the Universe 1110 West Green Street UrbanaIL61801 United States Los Alamos National Lab Los AlamosNM87545 United States Steward Observatory Department of Astronomy University of Arizona 933 N. Cherry Ave. TucsonAZ85721 United States Data Science Institute University of Arizona 1230 N. Cherry Ave. TucsonAZ85721 United States Program in Applied Mathematics University of Arizona 617 N. Santa Rita TucsonAZ85721 United States Max-Planck-Institut für Radioastronomie Auf dem Hügel 69 BonnD-53121 Germany Department of Astronomy University of Illinois 1002 West Green Street UrbanaIL61801 United States National Center for Supercomputing Applications 605 East Springfield Avenue ChampaignIL61820 United States

Models of the resolved Event Horizon Telescope (EHT) sources Sgr A* and M87* are constrained by observations at multiple wavelengths, resolutions, polarizations, and time cadences. In this paper we compare unresolved circular polarization (CP) measurements to a library of models, where each model is characterized by a distribution of CP over time. In the library we vary the spin of the black hole, the magnetic field strength at the horizon (i.e. both SANE and MAD models), the observer inclination, a parameter for the maximum ion-electron temperature ratio assuming a thermal plasma, and the direction of the magnetic field dipole moment. We find that ALMA observations of Sgr A* are inconsistent with all edge-on (i = 90◦) models. Restricting attention to the magnetically arrested disk (MAD) models favored by earlier EHT studies of Sgr A*, we find that only models with magnetic dipole moment pointing away from the observer are consistent with ALMA data. We also note that in 26 of the 27 passing MAD models the accretion flow rotates clockwise on the sky. We provide a table of the mean and standard deviation of the CP distributions for all model parameters along with their trends. © 2024, CC BY.

关键词： Stars

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Extended calculations with spectroscopic accuracy: Energy levels and radiative rates for o-like ions between Ar XI and Cr XVII

arXiv

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arXiv 2020年

作者： Song, C.X. Zhang, C.Y. Wang, Kai Si, R. Godefroid, M. Jönsson, P. Wei, D. Zhao, X.H. Yan, J. Chen, C.Y. Hebei Key Lab of Optic-electronic Information and Materials The College of Physics Science and Technology Hebei University Baoding071002 China Shanghai EBIT Lab Key Laboratory of Nuclear Physics and Ion-beam Application Institute of Modern Physics Department of Nuclear Science and Technology Fudan University Shanghai200433 China CP160/09 Université libre de Bruxelles Av. F.D. Roosevelt 50 Brussels1050 Belgium Department of Materials Science and Applied Mathematics Malmö University MalmöSE-20506 Sweden Institute of Applied Physics and Computational Mathematics Beijing100088 China

Using the multiconfiguration Dirac-Hartree-Fock and the relativistic configuration interaction methods, a consistent set of transition energies and radiative transition data for the main states of the 2s22p4, 2s2p5, 2p6, 2s22p33s, 2s22p33p, 2s22p33d, 2s2p43s, 2s2p43p, and 2s2p43d configurations in O-like Ions between Ar XI (Z = 18) and Cr XVII (Z = 24) is provided. Our data set is compared with the NIST compiled values and previous calculations. The data are accurate enough for identification and deblending of new emission lines from hot astrophysical and laboratory plasmas. The amount of data of high accuracy is significantly increased for the n = 3 states of several O-like ions, where experimental data are very scarce. Copyright © 2020, The Authors. All rights reserved.

关键词： Ions

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Quantum trajectories in spin-exchange collisions reveal the nature of spin-noise correlations in multispecies alkali-metal vapors

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Physical Review Research 2019年第3期1卷 033017-033017页

作者： K. Mouloudakis M. Loulakis I. K. Kominis Department of Physics University of Crete Heraklion 71003 Greece School of Applied Mathematical and Physical Sciences National Technical University of Athens 15780 Athens Greece Institute of Applied and Computational Mathematics FORTH 70013 Heraklion Greece Institute of Theoretical and Computational Physics University of Crete Heraklion 70013 Greece

Spin-exchange collisions in alkali-metal vapors underlie several fundamental and applied investigations such as nuclear structure studies and tests of fundamental symmetries, ultrasensitive atomic magnetometers, magnetic resonance, and biomagnetic imaging. Spin-exchange collisions cause a loss of spin coherence and concomitantly produce spin noise, both phenomena being central to quantum metrology. We develop here the quantum-trajectory picture of spin-exchange collisions, consistent with their long-standing ensemble description using density matrices. We then use quantum trajectories to reveal the nature of spin-noise correlations that spontaneously build up in multispecies atomic vapors, frequently utilized in the most sensitive spin measurements.

关键词： Atomic & molecular collisions Quantum metrology Quantum sensing

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Imaging Atomic-Scale Chemistry from Fused Multi-Modal Electron Microscopy

arXiv

引用

arXiv 2022年

作者： Schwartz, Jonathan Di, Zichao Wendy Jiang, Yi Fielitz, Alyssa J. Ha, Don-Hyung Perera, Sanjaya D. Baggari, Ismail El Robinson, Richard D. Fessler, Jeffrey A. Ophus, Colin Rozeveld, Steve Hovden, Robert Department of Materials Science and Engineering University of Michigan Ann ArborMI United States Mathematics and Computer Science Division Argonne National Laboratory LemontIL United States Advanced Photon Source Facility Argonne National Laboratory LemontIL United States Dow Chemical Co. MidlandMI United States Department of Material Science and Engineering Cornell University IthacaNY United States School of Integrative Engineering Chung-Ang University Seoul Korea Republic of Department of Physics Cornell University IthacaNY United States The Rowland Institute at Harvard CambridgeMA United States Department of Electrical Engineering and Computer Science University of Michigan Ann ArborMI United States National Center for Electron Microscopy Molecular Foundry Lawrence Berkeley National Laboratory BerkeleyCA United States Applied Physics Program University of Michigan Ann ArborMI United States

Efforts to map atomic-scale chemistry at low doses with minimal noise using electron microscopes are fundamentally limited by inelastic interactions. Here, fused multi-modal electron microscopy offers high signal-to-noise ratio (SNR) recovery of material chemistry at nano- and atomic- resolution by coupling correlated information encoded within both elastic scattering (high-angle annular dark field (HAADF)) and inelastic spectroscopic signals (electron energy loss (EELS) or energy-dispersive x-ray (EDX)). By linking these simultaneously acquired signals, or modalities, the chemical distribution within nanomaterials can be imaged at significantly lower doses with existing detector hardware. In many cases, the dose requirements can be reduced by over one order of magnitude. This high SNR recovery of chemistry is tested against simulated and experimental atomic resolution data of heterogeneous nanomaterials. © 2022, CC BY.

关键词： Electron microscopy

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Convergence acceleration of ensemble Kalman inversion in nonlinear settings

arXiv

引用

arXiv 2019年

作者： Chada, Neil K. Tong, Xin T. Applied Mathematics and Computational Science Program King Abdullah University of Science and Technology Thuwal23955 Saudi Arabia Department of Mathematics National University of Singapore 119077 Singapore

Many data-science problems can be formulated as an inverse problem, where the parameters are estimated by minimizing a proper loss function. When complicated black-box models are involved, derivative-free optimization tools are often needed. The ensemble Kalman filter (EnKF) is a particle-based derivative-free Bayesian algorithm originally designed for data assimilation. Recently, it has been applied to inverse problems for computational efficiency. The resulting algorithm, known as ensemble Kalman inversion (EKI), involves running an ensemble of particles with EnKF update rules so they can converge to a minimizer. In this article, we investigate EKI convergence in general nonlinear settings. To improve convergence speed and stability, we consider applying EKI with non-constant step-sizes and covariance inflation. We prove that EKI can hit critical points with finite steps in non-convex settings. We further prove that EKI converges to the global minimizer polynomially fast if the loss function is strongly convex. We verify the analysis presented with numerical experiments on two inverse problems. Copyright © 2019, The Authors. All rights reserved.

关键词： Inverse problems

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Dynamics and structure of monolayer polymer crystallites on graphene

arXiv

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arXiv 2020年

作者： Gulde, Max Rissanou, Anastassia N. Harmandaris, Vagelis Müller, Marcus Schäfer, Sascha Ropers, Claus 4th Physical Institute - Solids and Nanostructures University of Göttingen Göttingen37077 Germany Institute of Applied and Computational Mathematics Foundation for Research and Technology Hellas HeraklionCrete71110 Greece Department of Mathematics and Applied Mathematics University of Crete HeraklionCrete71409 Greece Institute for Theoretical Physics University of Göttingen Göttingen37077 Germany Fraunhofer Institute for High-Speed Dynamics Ernst-Mach-Institut Freiburg79104 Germany

Graphene-based nanostructured systems and van-der-Waals heterostructures comprise a material class of growing technological and scientific importance. Joining materials with vastly different properties, polymer-graphene heterosystems promise diverse applications in surface- and nanotechnology, including photovoltaics or nanotribology. Fundamentally, molecular adsorbates are prototypical systems to study confinement-induced phase transitions exhibiting intricate dynamics, which require a comprehensive understanding of the dynamical and static properties on molecular time and length scales. Here, we investigate the dynamics and the structure of a single polyethylene chain on free-standing graphene by means of molecular dynamics simulations. In equilibrium, the adsorbed polymer is orientationally linked to the graphene as two-dimensional folded-chain crystallites or, at elevated temperatures, as a floating solid. The associated superstructure can be reversibly melted on a picosecond time scale upon quasi-instantaneous substrate heating, involving ultrafast heterogeneous melting via a transient floating phase. Our findings elucidate time-resolved molecular-scale ordering and disordering phenomena in individual polymers interacting with solids, yielding complementary information to collective friction and viscosity, and linking to recent experimental observables from ultrafast electron diffraction. We anticipate that the approach will help in resolving non-equilibrium phenomena of hybrid polymeric systems over a broad range of time and length scales. Copyright © 2020, The Authors. All rights reserved.

关键词： Graphene

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A Mathematical Model for Linguistic Universals

arXiv

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arXiv 2019年

作者： Weinan, E. Zhou, Yajun Department of Mathematics & Program in Applied and Computational Mathematics Princeton University PrincetonNJ08544 United States Beijing Institute of Big Data Research Beijing100871 China

Inspired by chemical kinetics and neurobiology, we propose a mathematical theory for pattern recurrence in text documents, applicable to a wide variety of languages. We present a Markov model at the discourse level for Steven Pinker’s "mentalese", or chains of mental states that transcend the spoken/written forms. Such (potentially) universal temporal structures of textual patterns lead us to a language-independent semantic representation, or a translationally-invariant word embedding, thereby forming the common ground for both comprehensibility within a given language and translatability between different languages. Applying our model to documents of moderate lengths, without relying on external knowledge bases, we reconcile Noam Chomsky’s "poverty of stimulus" paradox with statistical learning of natural languages. Copyright © 2019, The Authors. All rights reserved.

关键词： Markov processes

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Reed-Muller Codes Polarize

Reed-Muller Codes Polarize

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Annual IEEE Symposium on Foundations of Computer Science

作者： Emmanuel Abbe Min Ye Mathematics Institute and the School of Computer and Communication Sciences at EPFL Switzerland Program in Applied and Computational Mathematics in Princeton University USA Department of Electrical Engineering Princeton University USA

Reed-Muller (RM) codes were introduced in 1954 and have long been conjectured to achieve Shannon's capacity on symmetric channels. The activity on this conjecture has recently been revived with the emergence of polar codes. RM codes and polar codes are generated by the same matrix G_m= [1/1 0/1] ^⊗m but using different subset of rows. RM codes select simply rows having largest weights. Polar codes select instead rows having the largest conditional mutual information proceeding top to down in G_m; while this is a more elaborate and channel-dependent rule, the top-to-down ordering allows Arikan to show that the conditional mutual information polarizes, and this gives directly a capacity-achieving code on any symmetric channel. RM codes are yet to be proved to have such a property, despite the recent success for the erasure channel. In this paper, we connect RM codes to polarization theory. We show that proceeding in the RM code ordering, i.e., not top-to-down but from the lightest to the heaviest rows in G_m, the conditional mutual information again polarizes. We further demonstrate that it does so faster than for polar codes. This implies that G_m contains another code, different than the polar code and called here the twin-RM code, that is provably capacity-achieving on any symmetric channel. This gives in particular a necessary condition for RM codes to achieve capacity on symmetric channels. It further gives a sufficient condition if the rows with largest conditional mutual information correspond to the heaviest rows, i.e., if the twin-RM code is the RM code. We demonstrate here that the two codes are at least similar and give further evidence that they are indeed the same.

关键词： Polar codes Mutual information Channel capacity Decoding Entropy Boolean functions

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Global simulations of self-gravitating magnetized protoplanetary disks

arXiv

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arXiv 2020年

作者： Deng, Hongping Mayer, Lucio Latter, Henrik Center for Theoretical Astrophysics and Cosmology Institute for Computational Science University of Zurich Winterthurerstrasse 190 Zurich8057 Switzerland Department of Applied Mathematics and Theoretical Physics University of Cambridge Centre for Mathematical Sciences Wilberforce Road CambridgeCB3 0WA United Kingdom

In the early stages of a protoplanetary disk, when its mass is a significant fraction of its star's, turbulence generated by gravitational instability (GI) should feature significantly in the disk's evolution. At the same time, the disk may be sufficiently ionised for magnetic fields to play some role in the dynamics. Though usually neglected, the impact of magnetism on the GI may be critical, with consequences for several processes: The efficiency of accretion, spiral structure formation, fragmentation, and the dynamics of solids. In this paper, we report on global three-dimensional magnetohydrodynamical simulations of a self-gravitating protoplanetary disk using the meshless finite mass (MFM) Lagrangian technique. We confirm that GI spiral waves trigger a dynamo that amplifies an initial magnetic field to nearly thermal amplitudes (plasma β Copyright © 2020, The Authors. All rights reserved.

关键词： Magnetohydrodynamics

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