Mass, Momentum and Kinetic Energy of a Relativistic Particle
Zanchini, Enzo
2010-01-01
A rigorous definition of mass in special relativity, proposed in a recent paper, is recalled and employed to obtain simple and rigorous deductions of the expressions of momentum and kinetic energy for a relativistic particle. The whole logical framework appears as the natural extension of the classical one. Only the first, second and third laws of…
THE MAXIMUM ENERGY OF ACCELERATED PARTICLES IN RELATIVISTIC COLLISIONLESS SHOCKS
Sironi, Lorenzo [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Spitkovsky, Anatoly [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544-1001 (United States); Arons, Jonathan, E-mail: lsironi@cfa.harvard.edu [Department of Astronomy, Department of Physics, and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720 (United States)
2013-07-01
The afterglow emission from gamma-ray bursts (GRBs) is usually interpreted as synchrotron radiation from electrons accelerated at the GRB external shock that propagates with relativistic velocities into the magnetized interstellar medium. By means of multi-dimensional particle-in-cell simulations, we investigate the acceleration performance of weakly magnetized relativistic shocks, in the magnetization range 0 {approx}< {sigma} {approx}< 10{sup -1}. The pre-shock magnetic field is orthogonal to the flow, as generically expected for relativistic shocks. We find that relativistic perpendicular shocks propagating in electron-positron plasmas are efficient particle accelerators if the magnetization is {sigma} {approx}< 10{sup -3}. For electron-ion plasmas, the transition to efficient acceleration occurs for {sigma} {approx}< 3 Multiplication-Sign 10{sup -5}. Here, the acceleration process proceeds similarly for the two species, since the electrons enter the shock nearly in equipartition with the ions, as a result of strong pre-heating in the self-generated upstream turbulence. In both electron-positron and electron-ion shocks, we find that the maximum energy of the accelerated particles scales in time as {epsilon}{sub max}{proportional_to}t {sup 1/2}. This scaling is shallower than the so-called (and commonly assumed) Bohm limit {epsilon}{sub max}{proportional_to}t, and it naturally results from the small-scale nature of the Weibel turbulence generated in the shock layer. In magnetized plasmas, the energy of the accelerated particles increases until it reaches a saturation value {epsilon}{sub sat}/{gamma}{sub 0} m{sub i}c {sup 2} {approx} {sigma}{sup -1/4}, where {gamma}{sub 0} m{sub i}c {sup 2} is the mean energy per particle in the upstream bulk flow. Further energization is prevented by the fact that the self-generated turbulence is confined within a finite region of thickness {proportional_to}{sigma}{sup -1/2} around the shock. Our results can provide physically
The Maximum Energy of Accelerated Particles in Relativistic Collisionless Shocks
Sironi, Lorenzo; Arons, Jonathan
2013-01-01
The afterglow emission from gamma-ray bursts (GRBs) is usually interpreted as synchrotron radiation from electrons accelerated at the GRB external shock, that propagates with relativistic velocities into the magnetized interstellar medium. By means of multi-dimensional particle-in-cell simulations, we investigate the acceleration performance of weakly magnetized relativistic shocks, in the magnetization range 0
Geometrical Unification of Gravitation and Dark Energy: The Universe as a Relativistic Particle
Hojman, Sergio A; Rubio, Carlos A
2014-01-01
The Lagrangian, the Hamilton--Jacobi equation and the Schr\\"{o}dinger, Dirac and Klein--Gordon equations for the Friedmann--Robertson--Walker--Quintessence (FRWQ) system are presented and solved exactly for different interesting scenarios. The classical Lagrangian reproduces the usual two (second order) dynamical equations for the radius of the Universe and for the scalar field as well as the (first order) constraint equation. The approach naturally unifies gravity and dark energy, which may be related to the tlaplon (scalar torsion potential). The Lagrangian and the equations of motion are those of a relativistic particle moving on a two dimensional spacetime where the conformal metric factor is related to the dark energy scalar field potential. This allows us to quantize the system, obtaining a Klein-Gordon equation when the Universe is considered as a spinless particle, and a Dirac equation when the Universe is thought as a relativistic spin particle.
Liu, Ruoyu
2015-06-10
Ultrahigh energy cosmic rays are extreme energetic particles from outer space. They have aroused great interest among scientists for more than fifty years. However, due to the rarity of the events and complexity of the process of their propagation to Earth, they are still one of the biggest puzzles in modern high energy astrophysics. This dissertation is dedicated to study the origin of ultrahigh energy cosmic rays from various aspects. Firstly, we discuss a possible link between recently discovered sub-PeV/PeV neutrinos and ultrahigh energy cosmic rays. If these two kinds of particles share the same origin, the observation of neutrinos may provide additional and non-trivial constraints on the sources of ultrahigh energy cosmic rays. Secondly, we jointly employ the chemical composition measurement and the arrival directions of ultrahigh energy cosmic rays, and find a robust upper limit for distances of sources of ultrahigh energy cosmic rays above ∝55 EeV, as well as a lower limit for their metallicities. Finally, we study the shear acceleration mechanism in relativistic jets, which is a more efficient mechanism for the acceleration of higher energy particle. We compute the acceleration efficiency and the time-dependent particle energy spectrum, and explore the feature of synchrotron radiation of the accelerated particles. The possible realizations of this mechanism for acceleration of ultrahigh energy cosmic rays in different astrophysical environments is also discussed.
Zabalza, Víctor
2015-01-01
The ultimate goal of the observation of nonthermal emission from astrophysical sources is to understand the underlying particle acceleration and evolution processes, and few tools are publicly available to infer the particle distribution properties from the observed photon spectra from X-ray to VHE gamma rays. Here I present naima, an open source Python package that provides models for nonthermal radiative emission from homogeneous distribution of relativistic electrons and protons. Contributions from synchrotron, inverse Compton, nonthermal bremsstrahlung, and neutral-pion decay can be computed for a series of functional shapes of the particle energy distributions, with the possibility of using user-defined particle distribution functions. In addition, naima provides a set of functions that allow to use these models to fit observed nonthermal spectra through an MCMC procedure, obtaining probability distribution functions for the particle distribution parameters. Here I present the models and methods availabl...
Fractional Dynamics of Relativistic Particle
Tarasov, Vasily E
2011-01-01
Fractional dynamics of relativistic particle is discussed. Derivatives of fractional orders with respect to proper time describe long-term memory effects that correspond to intrinsic dissipative processes. Relativistic particle subjected to a non-potential four-force is considered as a nonholonomic system. The nonholonomic constraint in four-dimensional space-time represents the relativistic invariance by the equation for four-velocity u_{\\mu} u^{\\mu}+c^2=0, where c is a speed of light in vacuum. In the general case, the fractional dynamics of relativistic particle is described as non-Hamiltonian and dissipative. Conditions for fractional relativistic particle to be a Hamiltonian system are considered.
Decowski, M P
2002-01-01
The properties of quantum chromodynamics (QCD), the modern theory of the strong interaction, can be investigated through the study of relativistic nucleus- nucleus collisions. Recently, the Relativistic Heavy-Ion Collider (RHIC) was completed and started taking data at ten times higher center-of-mass energies than the previous most energetic heavy-ion collisions. This thesis presents some of the first measurements at RHIC from any experiment. The PHOBOS detector is used to measure the charged particle pseudo- rapidity density at mid-rapidity (i.e., in |η| < 1) as a function of collision energy and centrality. The multiplicity is measured by counting short tracks in the silicon spectrometer; the centrality measurement uses two scintillator detectors covering 3 < |η| < 4.5. The charged particle multiplicity at mid-rapidity for the 6% most central collisions is 379 ± 9(stat.) ± 42(syst.), 555 ± 3(stat.) ± 35(syst.) and 661 &plus...
Relativistic Particles in Clusters of Galaxies
Ensslin, T A
2002-01-01
A brief overview on the theory and observations of relativistic particle populations in clusters of galaxies is given. The following topics are addressed: (i) the diffuse relativistic electron population within the intra-cluster medium (ICM) as seen in the cluster wide radio halos and possibly also seen in the high energy X-ray and extreme ultraviolet excess emissions of some clusters, (ii) the observed confined relativistic electrons within fresh and old radio plasma and their connection to cluster radio relics at cluster merger shock waves, (iii) the relativistic proton population within the ICM, and its observable consequences (if it exists), and (iv) the confined relativistic proton population (if it exists) within radio plasma. The importance of upcoming, sensitive gamma-ray telescopes for this research area is highlighted.
Scattering in Relativistic Particle Mechanics.
de Bievre, Stephan
The problem of direct interaction in relativistic particle mechanics has been extensively studied and a variety of models has been proposed avoiding the conclusions of the so-called no-interaction theorems. In this thesis we study scattering in the relativistic two-body problem. We use our results to analyse gauge invariance in Hamiltonian constraint models and the uniqueness of the symplectic structure in manifestly covariant relativistic particle mechanics. We first present a general geometric framework that underlies approaches to relativistic particle mechanics. This permits a model-independent and geometric definition of the notions of asymptotic completeness and of Moller and scattering operators. Subsequent analysis of these concepts divides into two parts. First, we study the kinematic properties of the scattering transformation, i.e. those properties that arise solely from the invariance of the theory under the Poincare group. We classify all canonical (symplectic) scattering transformations on the relativistic phase space for two free particles in terms of a single function of the two invariants of the theory. We show how this function is determined by the center of mass time delay and scattering angle and vice versa. The second part of our analysis of the relativistic two-body scattering problem is devoted to the dynamical properties of the scattering process. Hence, we turn to two approaches to relativistic particle mechanics: the Hamiltonian constraint models and the manifestly covariant formalism. Using general geometric arguments, we prove "gauge invariance" of the scattering transformation in the Todorov -Komar Hamiltonian constraint model. We conclude that the scattering cross sections of the Todorov-Komar models have the same angular dependence as their non-relativistic counterpart, irrespective of a choice of gauge. This limits the physical relevance of those models. We present a physically non -trivial Hamiltonian constraint model, starting from
Relativistic particle acceleration in developing Alfv\\'{e}n turbulence
Matsukiyo, S; 10.1088/0004-637X/692/2/1004
2009-01-01
A new particle acceleration process in a developing Alfv\\'{e}n turbulence in the course of successive parametric instabilities of a relativistic pair plasma is investigated by utilyzing one-dimensional electromagnetic full particle code. Coherent wave-particle interactions result in efficient particle acceleration leading to a power-law like energy distribution function. In the simulation high energy particles having large relativistic masses are preferentially accelerated as the turbulence spectrum evolves in time. Main acceleration mechanism is simultaneous relativistic resonance between a particle and two different waves. An analytical expression of maximum attainable energy in such wave-particle interactions is derived.
Fauad Rami
2003-05-01
Charged particle pseudorapidity distributions have been measured in Au + Au collisions using the BRAHMS detector at RHIC. The results are presented as a function of the collision centrality and the center of mass energy. They are compared to the predictions of different parton scattering models and the important role of hard scattering processes at RHIC energies is discussed.
Minimal relativistic three-particle equations
Lindesay, J.
1981-07-01
A minimal self-consistent set of covariant and unitary three-particle equations is presented. Numerical results are obtained for three-particle bound states, elastic scattering and rearrangement of bound pairs with a third particle, and amplitudes for breakup into states of three free particles. The mathematical form of the three-particle bound state equations is explored; constraints are set upon the range of eigenvalues and number of eigenstates of these one parameter equations. The behavior of the number of eigenstates as the two-body binding energy decreases to zero in a covariant context generalizes results previously obtained non-relativistically by V. Efimov.
Spinless relativistic particle in energy-dependent potential and normalization of the wave function
Benchikha, Amar; Chetouani, Lyazid
2014-06-01
The problem of normalization related to a Klein-Gordon particle subjected to vector plus scalar energy-dependent potentials is clarified in the context of the path integral approach. In addition the correction relating to the normalizing constant of wave functions is exactly determined. As examples, the energy dependent linear and Coulomb potentials are considered. The wave functions obtained via spectral decomposition, were found exactly normalized.
Relativistic mixtures of charged and uncharged particles
Kremer, Gilberto M. [Departamento de Física, Universidade Federal do Paraná, Curitiba (Brazil)
2014-01-14
Mixtures of relativistic gases within the framework of Boltzmann equation are analyzed. Three systems are considered. The first one refers to a mixture of uncharged particles by using Grad’s moment method, where the relativistic mixture is characterized by the moments of the distribution functions: particle four-flows, energy-momentum tensors, and third-order moment tensors. In the second Fick’s law for a mixture of relativistic gases of non-disparate rest masses in a Schwarzschild metric are derived from an extension of Marle and McCormack model equations applied to a relativistic truncated Grad’s distribution function, where it is shown the dependence of the diffusion coefficient on the gravitational potential. The third one consists in the derivation of the relativistic laws of Ohm and Fourier for a binary mixtures of electrons with protons and electrons with photons subjected to external electromagnetic fields and in presence of gravitational fields by using the Anderson and Witting model of the Boltzmann equation.
Radiation reaction in a system of relativistic gravitating particles
Galtsov, D. V.
A Lorentz-covariant approach is developed to the description of electromagnetic and gravitational radiation in general relativity. A model of a relativistic system of gravitating point particles is constructed in which energy losses can be interpreted in terms of radiation-reaction forces. These forces are applied not only to the point particles but also to fields generated by these particles in the near zone. It is concluded that radiation friction in a system of relativistic gravitating particles is collective in character.
Relativistic collisions of structured atomic particles
Voitkiv, A.; Ullrich, J. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)
2008-07-01
The book reviews the progress achieved over the last decade in the study of collisions between an ion and an atom in which both the atomic particles carry electrons and can undergo transitions between their internal states - including continua. It presents the detailed considerations of different theoretical approaches, that can be used to describe collisions of structured atomic particles for the very broad interval of impact energies ranging from 0.5-1 MeV/u till extreme relativistic energies where the collision velocity very closely approaches the speed of light. (orig.)
Gestrina, G N
2005-01-01
The relativistic effect of energy increase in a particle freely moving in vacuum is discussed on the basis of quantum field theory and probability theory using some ideas of super-symmetrical theories. The particle is assumed to consist of a "seed" whose energy is equal to the particle rest energy and whose pulse is equal to the product of the particle mass by its velocity and of a "fur coat" - the system of virtual quanta of the material field - vacuum. Each of these quanta possesses the same energy and pulse as the "seed" but have no mass. The system of the quanta is in a state being the superposition of quantum states with energies and pulses multiple of the "seed" energy and pulse. The virtual quanta is created (or destroyed) in of such states. The probability of creating a quanta in any state is the inverse of the relativistic factor, and the average number of the quanta making up the "fur coat" with a "seed" is equal to this particular factor. The kinetic energy and the relativistic addition to the part...
The Beam-Density Effect on Energy Loss of a Relativistic Charged Particle Beam.
1983-09-01
media. t iU NSWC TR 83-348 Folloving the method developed by Sternheimer 24 in his calculations of the Fermi density effect, i l L2 -2in.v-v 2 (2.16...where Z 2v 2 + f.. The Sternheimer factor P is chosen so that the i i i value of the Bethe logarithm, InI, obtained in non-relativistic experiments, is...first three eigenfrequencies were taken from Reference 25. A more recent set has been given by Sternheimer and Peierls,2 6 but the ones of Reference 25
Trans-Relativistic Particle Acceleration in Astrophysical Plasmas
Becker, Peter A.; Subramanian, P.
2014-01-01
Trans-relativistic particle acceleration due to Fermi interactions between charged particles and MHD waves helps to power the observed high-energy emission in AGN transients and solar flares. The trans-relativistic acceleration process is challenging to treat analytically due to the complicated momentum dependence of the momentum diffusion coefficient. For this reason, most existing analytical treatments of particle acceleration assume that the injected seed particles are already relativistic, and therefore they are not suited to study trans-relativistic acceleration. The lack of an analytical model has forced workers to rely on numerical simulations to obtain particle spectra describing the trans-relativistic case. In this work we present the first analytical solution to the global, trans-relativistic problem describing the acceleration of seed particles due to hard-sphere collisions with MHD waves. The new results include the exact solution for the steady-state Green's function resulting from the continual injection of monoenergetic seed particles with an arbitrary energy. We also introduce an approximate treatment of the trans-relativistic acceleration process based on a hybrid form for the momentum diffusion coefficient, given by the sum of the two asymptotic forms. We refer to this process as "quasi hard-sphere scattering." The main advantage of the hybrid approximation is that it allows the extension of the physical model to include (i) the effects of synchrotron and inverse-Compton losses and (ii) time dependence. The new analytical results can be used to model the trans-relativistic acceleration of particles in AGN and solar environments, and can also be used to compute the spectra of the associated synchrotron and inverse-Compton emission. Applications of both types are discussed. We highlight (i) relativistic ion acceleration in black hole accretion coronae, and (ii) the production of gyrosynchrotron microwave emission due to relativistic electron
Particle energisation in a collapsing magnetic trap model: the relativistic regime
Oskoui, Solmaz Eradat
2014-01-01
In solar flares, a large number of charged particles is accelerated to high energies. By which physical processes this is achieved is one of the main open problems in solar physics. It has been suggested that during a flare, regions of the rapidly relaxing magnetic field can form a collapsing magnetic trap (CMT) and that this trap may contribute to particle energisation.} In this Research Note we focus on a particular analytical CMT model based on kinematic magnetohydrodynamics. Previous investigations of particle acceleration for this CMT model focused on the non-relativistic energy regime. It is the specific aim of this Research Note to extend the previous work to relativistic particle energies. Particle orbits were calculated numerically using the relativistic guiding centre equations. We also calculated particle orbits using the non-relativistic guiding centre equations for comparison. For mildly relativistic energies the relativistic and non-relativistic particle orbits mainly agree well, but clear devia...
Radiation reaction in a system of relativistic gravitating particles
Galtsov, D.V.
1983-01-01
A Lorentz-covariant approach is developed to the description of electromagnetic and gravitational radiation in general relativity. A model of a relativistic system of gravitating point particles is constructed in which energy losses can be interpreted in terms of radiation-reaction forces. These forces are applied not only to the point particles but also to fields generated by these particles in the near zone. It is concluded that radiation friction in a system of relativistic gravitating particles is collective in character. 16 references.
Turner, Drew; Gkioulidou, Matina; Ukhorskiy, Aleksandr; Gabrielse, Christine; Runov, Andrei; Angelopoulos, Vassilis
2014-05-01
Earth's radiation belts provide a natural laboratory to study a variety of physical mechanisms important for understanding the nature of energetic particles throughout the Universe. The outer electron belt is a particularly variable population, with drastic changes in relativistic electron intensities occurring on a variety of timescales ranging from seconds to decades. Outer belt variability ultimately results from the complex interplay between different source, loss, and transport processes, and all of these processes are related to the dynamics of the inner magnetosphere. Currently, an unprecedented number of spacecraft are providing in situ observations of the inner magnetospheric environment, including missions such as NASA's THEMIS and Van Allen Probes and ESA's Cluster and operational monitors such as NOAA's GOES and POES constellations. From a sampling of case studies using multi-point observations, we present examples showcasing the significant importance of two processes to outer belt dynamics: energetic particle injections and wave-particle interactions. Energetic particle injections are transient events that tie the inner magnetosphere to the near-Earth magnetotail; they involve the rapid inward transport of plasmasheet particles into the trapping zone in the inner magnetosphere. We briefly review key concepts and present new evidence from Van Allen Probes, GOES, and THEMIS of how these injections provide: 1. the seed population of electrons that are subsequently accelerated locally to relativistic energies in the outer belt and 2. the source populations of ions and electrons that produce a variety of ULF and VLF waves, which are also important for driving outer belt dynamics via wave-particle interactions. Cases of electron acceleration by chorus waves, losses by plasmaspheric hiss and EMIC waves, and radial transport driven by ULF waves will also be presented. Finally, we discuss the implications of this developing picture of the system, namely how
Non-relativistic classical mechanics for spinning particles
Salesi, G
2004-01-01
We study the classical dynamics of non-relativistic particles endowed with spin. Non-vanishing Zitterbewegung terms appear in the equation of motion also in the small momentum limit. We derive a generalized work-energy theorem which suggests classical interpretations for tunnel effect and quantum potential.
Particle Acceleration in Relativistic Magnetized Collisionless Electron-Ion Shocks
Sironi, Lorenzo
2010-01-01
We investigate shock structure and particle acceleration in relativistic magnetized collisionless electron-ion shocks by means of 2.5D particle-in-cell simulations with ion-to-electron mass ratios (m_i/m_e) ranging from 16 to 1000. We explore a range of inclination angles between the pre-shock magnetic field and the shock normal. In "subluminal" shocks, where relativistic particles can escape ahead of the shock along the magnetic field lines, ions are efficiently accelerated via a Fermi-like mechanism. The downstream ion spectrum consists of a relativistic Maxwellian and a high-energy power-law tail, which contains ~5% of ions and ~30% of ion energy. Its slope is -2.1. Upstream electrons enter the shock with lower energy than ions, so they are more strongly tied to the field. As a result, only ~1% of the incoming electrons are Fermi-accelerated at the shock before being advected downstream, where they populate a steep power-law tail (with slope -3.5). For "superluminal" shocks, where relativistic particles ca...
Adamczyk, L; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E; Averichev, G S; Balewski, J; Banerjee, A; Barnovska, Z; Beavis, D R; Bellwied, R; Betancourt, M J; Betts, R R; Bhasin, A; Bhati, A K; Bhattarai,; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bruna, E; Bültmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Sánchez, M Calderón de la Barca; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, J Y; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chung, P; Chwastowski, J; Codrington, M J M; Corliss, R; Cramer, J G; Crawford, H J; Cui, X; Das, S; Leyva, A Davila; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; de Souza, R Derradi; Dhamija, S; di Ruzza, B; Didenko, L; Dilks,; Ding, F; Dion, A; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Elnimr, M; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Fatemi, R; Fazio, S; Fedorisin, J; Fersch, R G; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Gliske, S; Grebenyuk, O G; Grosnick, D; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hajkova, O; Hamed, A; Han, L-X; Haque, R; Harris, J W; Hays-Wehle, J P; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jena, C; Judd, E G; Kabana, S; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Kikola, D P; Kiryluk, J; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Korsch, W; Kotchenda, L; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Lamont, M A C; Landgraf, J M; Landry, K D; LaPointe, S; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; Leight, W; LeVine, M J; Li, C; Li, W; Li, X; Li, Y; Li, Z M; Lima, L M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Longacre, R S; Luo, X; Luszczak, A; Ma, G L; Ma, Y G; Don, D M M D Madagodagettige; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Mioduszewski, S; Mitrovski, M K; Mohammed, Y; Mohanty, B; Mondal, M M; Munhoz, M G; Mustafa, M K; Naglis, M; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nogach, L V; Novak, J; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Oliveira, R A N; Olson, D; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Plyku, D; Poljak, N; Porter, J; Poskanzer, A M; Powell, C B; Pruneau, C; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandacz, A; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, B; Schmitz, N; Schuster, T R; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shao, M; Sharma, B; Sharma, M; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; deSouza, U G; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Suaide, A A P; Suarez, M C; Sumbera, M; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; de Toledo, A Szanto; Takahashi, J; Tang, A H; Tang, Z; Tarini, L H; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vanfossen,, J A; Varma, R; Vasconcelos, G M S; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Vossen, A; Wada, M; Walker, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, Q; Wang, X L; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, N; Xu, Q H; Xu, W; Xu, Y; Xu, Z; Yan,; Yang, C; Yang, Y; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M
2013-01-01
Elliptic flow ($v_{2}$) values for identified particles at mid-rapidity in Au+Au collisions, measured by the STAR experiment in the Beam Energy Scan at RHIC at $\\sqrt{s_{NN}}=$ 7.7--62.4 GeV, are presented. A beam-energy dependent difference of the values of $v_{2}$ between particles and corresponding anti-particles was observed. The difference increases with decreasing beam energy and is larger for baryons compared to mesons. This implies that, at lower energies, particles and anti-particles are not consistent with the universal number-of-constituent-quark (NCQ) scaling of $v_{2}$ that was observed at $\\sqrt{s_{NN}}=$ 200 GeV.
Applying the relativistic quantization condition to a three-particle bound state in a periodic box
Hansen, Maxwell T
2016-01-01
Using our recently developed relativistic three-particle quantization condition, we study the finite-volume energy shift of a three-particle bound state. We reproduce the result obtained using non-relativistic quantum mechanics by Mei{\\ss}ner, R{\\'i}os and Rusetsky, and generalize the result to a moving frame.
Eigenenergies of a Relativistic Particle in an Infinite Range Linear Potential Using WKB Method
Shivalingaswamy, T.; Kagali, B. A.
2011-01-01
Energy eigenvalues for a non-relativistic particle in a linear potential well are available. In this paper we obtain the eigenenergies for a relativistic spin less particle in a similar potential using an extension of the well-known WKB method treating the potential as the time component of a four-vector potential. Since genuine bound states do…
A relativistic spin zero particle in a spherical cavity
Gouveia, Tomé M.; Fiolhais, Miguel C. N.; Birman, Joseph L.
2015-09-01
The problem of a relativistic massive scalar particle trapped in an infinite potential spherical well is pedagogically addressed in this paper. The wave function solutions and probability density of the Klein-Gordon equation in spherical coordinates are derived, as well as the energy levels. The results are compared with the non-relativistic solutions of the Schrödinger equation for different values of the particle’s mass. As expected, for very large masses the non-relativistic results are recovered. For illustration, these results are discussed in the specific case of the standard model Higgs field constrained inside a proton, in the quadratic approximation of the Higgs potential around the expectation value.
Analytical mechanics of a relativistic particle in a positional potential
Mignemi, S
2012-01-01
We propose a form for the action of a relativistic particle subject to a positional force that is invariant under time reparametrization and therefore allows for a consistent Hamiltonian formulation of the dynamics. This approach can be useful in the study of phenomenological models. Also the Dirac and Klein-Gordon equation differ from the standard formulation, with corrections of order (E-m)/m in the energy spectra.
Particle acceleration, magnetization and radiation in relativistic shocks
Derishev, Evgeny V.; Piran, Tsvi
2016-08-01
The mechanisms of particle acceleration and radiation, as well as magnetic field build-up and decay in relativistic collisionless shocks, are open questions with important implications to various phenomena in high-energy astrophysics. While the Weibel instability is possibly responsible for magnetic field build-up and diffusive shock acceleration is a model for acceleration, both have problems and current particle-in-cell simulations show that particles are accelerated only under special conditions and the magnetic field decays on a very short length-scale. We present here a novel model for the structure and the emission of highly relativistic collisionless shocks. The model takes into account (and is based on) non-local energy and momentum transport across the shock front via emission and absorption of high-energy photons. This leads to a pre-acceleration of the fluid and pre-amplification of the magnetic fields in the upstream region. Both have drastic implications on the shock structure. The model explains the persistence of the shock-generated magnetic field at large distances from the shock front. The dissipation of this magnetic field results in a continuous particle acceleration within the downstream region. A unique feature of the model is the existence of an `attractor', towards which any shock will evolve. The model is applicable to any relativistic shock, but its distinctive features show up only for sufficiently large compactness. We demonstrate that prompt and afterglow gamma-ray bursts' shocks satisfy the relevant conditions, and we compare their observations with the predictions of the model.
A Bilocal Model for the Relativistic Spinning Particle
Rempel, Trevor
2016-01-01
In this work we show that a relativistic spinning particle can be described at the classical and the quantum level as being composed of two physical constituents which are entangled and separated by a fixed distance. This bilocal model for spinning particles allows for a natural description of particle interactions as a local interaction at each of the constituents. This form of the interaction vertex provides a resolution to a long standing issue on the nature of relativistic interactions for spinning objects in the context of the worldline formalism. It also potentially brings a dynamical explanation for why massive fundamental objects are naturally of lowest spin. We analyze first a non-relativistic system where spin is modeled as an entangled state of two particles with the entanglement encoded into a set of constraints. It is shown that these constraints can be made relativistic and that the resulting description is isomorphic to the usual description of the phase space of massive relativistic particles ...
Spinning relativistic particle: some novel features
Krishna, S; Malik, R P
2012-01-01
For the newly proposed coupled (but equivalent) Lagrangians for the supersymmetric (SUSY) system of a one (0 + 1)-dimensional spinning relativistic particle, we derive the Noether conserved charges corresponding to its (super)gauge, Becchi-Rouet-Stora-Tyutin (BRST), anti-BRST and ghost-scale symmetry transformations. We deduce the underlying algebra amongst the continuous symmetry operators and corresponding conserved charges. We point out some novel observations that emerge, for this specific SUSY system, when we discuss it within the framework of BRST formalism. We also comment on the importance of Curci-Ferrari type restriction (which is also a novel feature of our present SUSY system) in the proof of the absolute anticommutativity of the off-shell nilpotent (anti-)BRST symmetries and corresponding charges.
One-dimensional quasi-relativistic particle in the box
Kaleta, Kamil; Malecki, Jacek
2011-01-01
Two-term Weyl-type asymptotic law for the eigenvalues of one-dimensional quasi-relativistic Hamiltonian (-h^2 c^2 d^2/dx^2 + m^2 c^4)^(1/2) + V_well(x) (the Klein-Gordon square-root operator with electrostatic potential) with the infinite square well potential V_well(x) is given: the n-th eigenvalue is equal to (n pi/2 - pi/8) h c/a + O(1/n), where 2a is the width of the potential well. Simplicity of eigenvalues is proved. Some L^2 and L^infinity properties of eigenfunctions are also studied. Eigenvalues represent energies of a `massive particle in the box' quasi-relativistic model.
Energy spectra in relativistic electron precipitation events.
Rosenberg, T. J.; Lanzerotti, L. J.; Bailey, D. K.; Pierson, J. D.
1972-01-01
Two events in August 1967, categorized as relativistic electron precipitation (REP) events by their effect on VHF transmissions propagated via the forward-scatter mode, have been examined with regard to the energy spectra of trapped and precipitated electrons. These two substorm-associated events August 11 and August 25 differ with respect to the relativistic, trapped electron population at synchronous altitude; in the August 25 event there was a nonadiabatic enhancement of relativistic (greater than 400 keV) electrons, while in the August 11 event no relativistic electrons were produced. In both events electron spectra deduced from bremsstrahlung measurements (made on a field line close to that of the satellite) had approximately the same e-folding energies as the trapped electron enhancements. However, the spectrum of electrons in the August 25 event was significantly harder than the spectrum in the event of August 11.
Particle Acceleration and Nonthermal Emission in Relativistic Astrophysical Shocks
Sironi, Lorenzo
The common observational feature of Pulsar Wind Nebulae (PWNe), gamma-ray bursts (GRBs), and AGN jets is a broad nonthermal spectrum of synchrotron and inverse Compton radiation. It is usually assumed that the emitting electrons are accelerated to a power-law distribution at relativistic shocks, via the so-called Fermi mechanism. Despite decades of research, the Fermi acceleration process is still not understood from first principles. An assessment of the micro-physics of particle acceleration in relativistic shocks is of paramount importance to unveil the properties of astrophysical nonthermal sources, and it is the subject of this dissertation. In the first part of this thesis, I explore by means of fully-kinetic first-principle particle-in-cell (PIC) simulations the properties of relativistic shocks that propagate in electron-positron and electron-proton plasmas carrying uniform magnetic fields. I find that nonthermal particle acceleration only occurs if the upstream magnetization is weak (sigma0.01) and quasi-perpendicular, yet they need to be efficient particle accelerators, in order to explain the prominent nonthermal signatures of these sources. Motivated by this discrepancy, I then relax the assumption of uniform pre-shock fields, and investigate the acceleration efficiency of perpendicular shocks that propagate in high-sigma flows with alternating magnetic fields. This is the geometry expected at the termination shock of pulsar winds, but it could also be relevant for Poynting-dominated jets in GRBs and AGNs. I show by means of PIC simulations that compression of the flow at the shock will force annihilation of nearby field lines, a process known as shock-driven reconnection. Magnetic reconnection can efficiently transfer the energy of alternating fields to the particles, generating flat power-law tails containing most of the particles. Finally, I directly relate the results of my PIC simulations to observations of nonthermal sources, by presenting a
Entanglement and nonlocality of a single relativistic particle
Dunningham, Jacob; Vedral, Vlatko
2009-01-01
Recent work has argued that the concepts of entanglement and nonlocality must be taken seriously even in systems consisting of only a single particle. These treatments, however, are nonrelativistic and, if single particle entanglement is fundamental, it should also persist in a relativistic description. Here we consider a spin-1/2 particle in a superposition of two different velocities as viewed by an observer in a different relativistically-boosted inertial frame. We show that the entangleme...
Vitória, R.L.L.; Furtado, C., E-mail: furtado@fisica.ufpb.br; Bakke, K., E-mail: kbakke@fisica.ufpb.br
2016-07-15
The relativistic quantum dynamics of an electrically charged particle subject to the Klein–Gordon oscillator and the Coulomb potential is investigated. By searching for relativistic bound states, a particular quantum effect can be observed: a dependence of the angular frequency of the Klein–Gordon oscillator on the quantum numbers of the system. The meaning of this behaviour of the angular frequency is that only some specific values of the angular frequency of the Klein–Gordon oscillator are permitted in order to obtain bound state solutions. As an example, we obtain both the angular frequency and the energy level associated with the ground state of the relativistic system. Further, we analyse the behaviour of a relativistic position-dependent mass particle subject to the Klein–Gordon oscillator and the Coulomb potential.
Vitória, R. L. L.; Furtado, C.; Bakke, K.
2016-07-01
The relativistic quantum dynamics of an electrically charged particle subject to the Klein-Gordon oscillator and the Coulomb potential is investigated. By searching for relativistic bound states, a particular quantum effect can be observed: a dependence of the angular frequency of the Klein-Gordon oscillator on the quantum numbers of the system. The meaning of this behaviour of the angular frequency is that only some specific values of the angular frequency of the Klein-Gordon oscillator are permitted in order to obtain bound state solutions. As an example, we obtain both the angular frequency and the energy level associated with the ground state of the relativistic system. Further, we analyse the behaviour of a relativistic position-dependent mass particle subject to the Klein-Gordon oscillator and the Coulomb potential.
Particle acceleration, magnetization and radiation in relativistic shocks
Derishev, Evgeny V
2015-01-01
What are the mechanisms of particle acceleration and radiation, as well as magnetic field build up and decay in relativistic shocks are open questions with important implications to various phenomena in high energy astrophysics. While the Weibel instability is possibly responsible for magnetic field build up and diffusive shock acceleration is a model for acceleration, both have problems and current PIC simulation show that particles are accelerated only under special conditions and the magnetic field decays on a short length scale. We present here a novel model for the structure and the emission of highly relativistic collisionless shocks. The model takes into account (and is based on) non-local energy and momentum transport across the shock front via emission and absorption of high-energy photons. This leads to a pre-acceleration of the fluid and pre-amplificaiton of the magnetic fields in the upstream region. Both have drastic implications on the shock structure. The model explains the persistence of the s...
Kinematics of a relativistic particle with de Sitter momentum space
Arzano, Michele [Institute for Theoretical Physics and Spinoza Institute, Utrecht University, Leuvenlaan 4, Utrecht 3584 TD (Netherlands); Kowalski-Glikman, Jerzy, E-mail: marzano@uu.nl, E-mail: jkowalskiglikman@ift.uni.wroc.pl [Institute for Theoretical Physics, University of Wroclaw, Pl. Maxa Borna 9, Pl-50-204 Wroclaw (Poland)
2011-05-21
We discuss kinematical properties of a free relativistic particle with deformed phase space in which momentum space is given by (a submanifold of) de Sitter space. We provide a detailed derivation of the action, Hamiltonian structure and equations of motion for such a free particle. We study the action of deformed relativistic symmetries on the phase space and derive explicit formulae for the action of the deformed Poincare group. Finally we provide a discussion on parametrization of the particle worldlines stressing analogies and differences with ordinary relativistic kinematics.
Non-relativistic particles in a thermal bath
Vairo Antonio
2014-04-01
Full Text Available Heavy particles are a window to new physics and new phenomena. Since the late eighties they are treated by means of effective field theories that fully exploit the symmetries and power counting typical of non-relativistic systems. More recently these effective field theories have been extended to describe non-relativistic particles propagating in a medium. After introducing some general features common to any non-relativistic effective field theory, we discuss two specific examples: heavy Majorana neutrinos colliding in a hot plasma of Standard Model particles in the early universe and quarkonia produced in heavy-ion collisions dissociating in a quark-gluon plasma.
Relativistic Momentum and Kinetic Energy, and E = mc[superscript 2
Hu, Ben Yu-Kuang
2009-01-01
Based on relativistic velocity addition and the conservation of momentum and energy, I present simple derivations of the expressions for the relativistic momentum and kinetic energy of a particle, and for the formula E = mc[superscript 2]. (Contains 5 footnotes and 2 figures.)
Particle creation due to tachyonic instability in relativistic stars
Landulfo, Andre G.S. [Universidade Federal do ABC (CCNH/UFABC), Santo Andre, SP (Brazil); Lima, William C.C.; Matsas, George E.A. [Universidade Estadual Paulista Julio de Mesquita Filho (IFT/UNESP), Sao Paulo, SP (Brazil); Vanzella, Daniel A.T. [Universidade de Sao Paulo (IFSC/USP), Sao Carlos, SP (Brazil). Instituto de Fisica
2013-07-01
Full text: It was recently shown that relativistic stars may become unstable due to quantum field effects. The so called vacuum awakening effect occurs for a free scalar field properly coupled to the spacetime curvature. This effect is characterized by an exponential point-dependent increase and decrease of the vacuum expectation value of the stress-energy-momentum tensor. This is caused by a tachyonic-like instability, which induces an exponential growth of the vacuum fluctuations. Once the effect is triggered, the star energy density would be overwhelmed by the vacuum energy density in a few milliseconds. This demands that eventually geometry and field evolve to a new configuration to bring the vacuum back to a stationary regime. Here, we show that the vacuum fluctuations built up during the unstable epoch lead to particle creation in the final stationary state when the tachyonic instability ceases. The amount of created particles depends mostly on the duration of the unstable epoch and final stationary configuration, which are open issues at this point. We emphasize that the particle creation coming from the tachyonic instability will occur even in the adiabatic limit, where the spacetime geometry changes arbitrarily slowly, and therefore is quite distinct from the usual particle creation due to the change in the background geometry. (author)
Relativistic energy loss in a dispersive medium
Houlrik, Jens Madsen
2002-01-01
The electron energy loss in a dispersive medium is obtained using macroscopic electrodynamics taking advantage of a static frame of reference. Relativistic corrections are described in terms of a dispersive Lorentz factor obtained by replacing the vacuum velocity c by the characteristic phase...
Relativistic energy loss in a dispersive medium
Houlrik, Jens Madsen
2002-01-01
The electron energy loss in a dispersive medium is obtained using macroscopic electrodynamics taking advantage of a static frame of reference. Relativistic corrections are described in terms of a dispersive Lorentz factor obtained by replacing the vacuum velocity c by the characteristic phase...
Beaming of particles and synchrotron radiation in relativistic magnetic reconnection
Kagan, Daniel; Piran, Tsvi
2016-01-01
Relativistic reconnection has been invoked as a mechanism for particle acceleration in numerous astrophysical systems. According to idealised analytical models reconnection produces a bulk relativistic outflow emerging from the reconnection sites (X-points). The resulting radiation is therefore highly beamed. Using two-dimensional particle-in-cell (PIC) simulations, we investigate particle and radiation beaming, finding a very different picture. Instead of having a relativistic average bulk motion with isotropic electron velocity distribution in its rest frame, we find that the bulk motion of particles in X-points is similar to their Lorentz factor gamma, and the particles are beamed within about 5/gamma. On the way from the X-point to the magnetic islands, particles turn in the magnetic field, forming a fan confined to the current sheet. Once they reach the islands they isotropise after completing a full Larmor gyration and their radiation is not strongly beamed anymore. The radiation pattern at a given freq...
Particle acceleration in ultra-relativistic parallel shock waves
Meli, A
2003-01-01
Monte-Carlo computations for highly relativistic parallel shock particle acceleration are presented for upstream flow gamma factors, $\\Gamma=(1-V_{1}^{2}/c^{2})^{-0.5}$ with values between 5 and $10^{3}$. The results show that the spectral shape at the shock depends on whether or not the particle scattering is small angle with $\\delta \\theta 2r_{g} \\Gamma^{2}$ where $\\lambda$ is the scattering mean free path along the field line and $r_{g}$ the gyroradius, these quantities being measured in the plasma flow frame. The large angle scattering case exhibits distinctive structure superimposed on the basic power-law spectrum, largely absent in the pitch angle case. Also, both cases yield an acceleration rate faster than estimated by the conventional, non-relativistic expression, $t_{acc}=[c/(V_{1}-V_{2})] [\\lambda_{1}/V_{1}+\\lambda_{2}/V_{2}]$ where '1' and '2' refer to upstream and downstream and $\\lambda$ is the mean free path. A $\\Gamma^{2}$ energy enhancement factor in the first shock crossing cycle and a sign...
Relativistic formulations with Blankenbecler-Sugar reduction technique for the three-particle system
Morioka, S.; Afnan, I. R.
1981-02-01
We present a critical comparison for two types of three-dimensional covariant equations for the three-particle system obtained by the Blankenbecler-Sugar reduction technique with the Wightman-Gårding momenta and the usual Jacobi variables. We also discuss the relations between the relativistic and nonrelativistic equations in the low-energy limit. NUCLEAR REACTIONS Relativistic Faddeev equations, Blankenbecler-Sugar reduction technique, nonrelativistic limit.
Salazar-Ramírez, M.; Ojeda-Guillén, D.; Mota, R. D.
2016-09-01
We study a relativistic quantum particle in cosmic string spacetime in the presence of a magnetic field and a Coulomb-type scalar potential. It is shown that the radial part of this problem possesses the su(1 , 1) symmetry. We obtain the energy spectrum and eigenfunctions of this problem by using two algebraic methods: the Schrödinger factorization and the tilting transformation. Finally, we give the explicit form of the relativistic coherent states for this problem.
Transport coefficients for relativistic gas mixtures of hard-sphere particles
Kremer, Gilberto M.; Moratto, Valdemar
2017-04-01
In the present work, we calculate the transport coefficients for a relativistic binary mixture of diluted gases of hard-sphere particles. The gas mixture under consideration is studied within the relativistic Boltzmann equation in the presence of a gravitational field described by the isotropic Schwarzschild metric. We obtain the linear constitutive equations for the thermodynamic fluxes. The driving forces for the fluxes of particles and heat will appear with terms proportional to the gradient of gravitational potential. We discuss the consequences of the gravitational dependence on the driving forces. We obtain general integral expressions for the transport coefficients and evaluate them by assuming a hard-sphere interaction amongst the particles when they collide and not very disparate masses and diameters of the particles of each species. The obtained results are expressed in terms of their temperature dependence through the relativistic parameter which gives the ratio of the rest energy of the particles and the thermal energy of the gas mixture. Plots are given to analyze the behavior of the transport coefficients with respect to the temperature when small variations in masses and diameters of the particles of the species are present. We also analyze for each coefficient the corresponding limits to a single gas so the non-relativistic and ultra-relativistic limiting cases are recovered as well. Furthermore, we show that the transport coefficients have a dependence on the gravitational field.
Uniqueness of Landau-Lifshitz energy frame in relativistic dissipative hydrodynamics.
Tsumura, Kyosuke; Kunihiro, Teiji
2013-05-01
We show that the relativistic dissipative hydrodynamic equation derived from the relativistic Boltzmann equation by the renormalization-group method uniquely leads to the one in the energy frame proposed by Landau and Lifshitz, provided that the macroscopic-frame vector, which defines the local rest frame of the flow velocity, is independent of the momenta of constituent particles, as it should. We argue that the relativistic hydrodynamic equations for viscous fluids must be defined on the energy frame if consistent with the underlying relativistic kinetic equation.
On the time delay between ultra-relativistic particles
Pierre Fleury
2016-09-01
Full Text Available The time delay between the receptions of ultra-relativistic particles emitted simultaneously is a useful observable for both fundamental physics and cosmology. The expression of the delay when the particles travel through an arbitrary spacetime has been derived recently by Fanizza et al., using a particular coordinate system and self-consistent assumptions. The present article shows that this formula enjoys a simple physical interpretation: the relative velocity between two ultra-relativistic particles is constant. This result reveals an interesting kinematical property of general relativity, namely that the tidal forces experienced by ultra-relativistic particles in the direction of their motion are much smaller than those experienced orthogonally to their motion.
On the time delay between ultra-relativistic particles
Fleury, Pierre
2016-09-01
The time delay between the receptions of ultra-relativistic particles emitted simultaneously is a useful observable for both fundamental physics and cosmology. The expression of the delay when the particles travel through an arbitrary spacetime has been derived recently by Fanizza et al., using a particular coordinate system and self-consistent assumptions. The present article shows that this formula enjoys a simple physical interpretation: the relative velocity between two ultra-relativistic particles is constant. This result reveals an interesting kinematical property of general relativity, namely that the tidal forces experienced by ultra-relativistic particles in the direction of their motion are much smaller than those experienced orthogonally to their motion.
The relativistic solar particle event of 2005 January 20: prompt and delayed particle acceleration
Klein, K -L; Bouratzis, C; Grechnev, V; Hillaris, A; Preka-Papadema, P
2014-01-01
The highest energies of solar energetic nucleons detected in space or through gamma-ray emission in the solar atmosphere are in the GeV range. Where and how the particles are accelerated is still controversial. We search for observational evidence on the acceleration region(s) by comparing the timing of relativistic protons detected at Earth and radiative signatures in the solar atmosphere. To this end a detailed comparison is undertaken of the double-peaked time profile of relativistic protons, derived from the worldwide network of neutron monitors during the large particle event of 2005 January 20, with UV imaging and radio petrography over a broad frequency band from the low corona to interplanetary space. We show that both relativistic proton releases to interplanetary space were accompanied by distinct episodes of energy release and electron acceleration in the corona traced by the radio emission and by brightenings of UV kernels in the low solar atmosphere. The timing of electromagnetic emissions and re...
Relativistic Motion of Spinning Particles in a Gravitational Field
Chicone, C.; Mashhoon, B.; Punsly, B.
2005-01-01
The relative motion of a classical relativistic spinning test particle is studied with respect to a nearby free test particle in the gravitational field of a rotating source. The effects of the spin-curvature coupling force are elucidated and the implications of the results for the motion of rotating plasma clumps in astrophysical jets are discussed.
Relativistic motion of spinning particles in a gravitational field
Chicone, C.; Mashhoon, B.; Punsly, B.
2005-08-01
The relative motion of a classical relativistic spinning test particle is studied with respect to a nearby free test particle in the gravitational field of a rotating source. The effects of the spin-curvature coupling force are elucidated and the implications of the results for the motion of rotating plasma clumps in astrophysical jets are discussed.
Relativistic Spinning Particle without Grassmann Variables and the Dirac Equation
A. A. Deriglazov
2011-01-01
Full Text Available We present the relativistic particle model without Grassmann variables which, being canonically quantized, leads to the Dirac equation. Classical dynamics of the model is in correspondence with the dynamics of mean values of the corresponding operators in the Dirac theory. Classical equations for the spin tensor are the same as those of the Barut-Zanghi model of spinning particle.
Theory of non-relativistic three-particle scattering
Malfliet, R.; Ruijgrok, Th.
1967-01-01
A new method, using asymptotically stationary states, is developed to calculate the S-matrix for the scattering of a non-relativistic particle by the bound state of two other particles. For the scattering with breakup of this bound state, we obtain a simplified form of the Faddeev integral
H. K. Avetissian
2010-10-01
Full Text Available The nonlinear threshold phenomena of particle reflection and capture of electrons in the induced Compton process that have previously been revealed in the case of plane monochromatic counterpropagating waves, take place also with the actual nonplane laser pulses of ultrashort duration and lead to particle acceleration. In contrast to analogous phenomena in the induced Cherenkov and undulator processes, the Compton reflection-capture mechanism with laser pulses of relativistic intensities practically may be realized for arbitrary initial energies of particles. The acceleration effect for particles initially in rest is explored numerically, taking into account the significance of this case connected with the relativistic electron bunches of high densities, which currently may be realized by relativistic lasers on the ultrathin solid foils where the electrons initially are almost in rest.
Energy eigenvalues of spherical symmetric potentials with relativistic corrections: analytic results
Dineykhan, M; Zhaugasheva, S A [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation); Toinbaeva, N Sh [al-Farabi Kazak National University, Almaty (Kazakhstan)
2010-01-14
Based on the investigation of the asymptotic behaviour of the polarization loop function for charged n scalar particles in an external gauge field, we determine the interaction Hamiltonian including the relativistic corrections. The energy eigenvalues of spherical symmetric potentials for two-particle bound state systems with relativistic corrections are analytically derived. The energy spectra of linear and funnel potentials with orbital and radial excitations are determined. The energy spectrum of a superposition of Coulomb and Yukawa potentials is also determined. Our result shows that the energy spectrum with the relativistic corrections for the linear, harmonic oscillator and funnel potentials is smaller than the upper boundaries for the energy spectrum established in the framework of the spinless Salpeter equation for the orbital and radial excited states. The relativistic corrections to the energy spectrum of a superposition of the attractive Coulomb potential and the Yukawa (exponentially screened Coulomb) potentials are very small.
Relativistic propulsion using directed energy
Bible, Johanna; Johansson, Isabella; Hughes, Gary B.; Lubin, Philip M.
2013-09-01
We propose a directed energy orbital planetary defense system capable of heating the surface of potentially hazardous objects to the evaporation point as a futuristic but feasible approach to impact risk mitigation. The system is based on recent advances in high efficiency photonic systems. The system could also be used for propulsion of kinetic or nuclear tipped asteroid interceptors or other interplanetary spacecraft. A photon drive is possible using direct photon pressure on a spacecraft similar to a solar sail. Given a laser power of 70GW, a 100 kg craft can be propelled to 1AU in approximately 3 days achieving a speed of 0.4% the speed of light, and a 10,000 kg craft in approximately 30 days. We call the system DE-STAR for Directed Energy System for Targeting of Asteroids and exploRation. DE-STAR is a modular phased array of solid-state lasers, powered by photovoltaic conversion of sunlight. The system is scalable and completely modular so that sub elements can be built and tested as the technology matures. The sub elements can be immediately utilized for testing as well as other applications including space debris mitigation. The ultimate objective of DE-STAR would be to begin direct asteroid vaporization and orbital modification starting at distances beyond 1 AU. Using phased array technology to focus the beam, the surface spot temperature on the asteroid can be raised to more than 3000K, allowing evaporation of all known substances. Additional scientific uses of DE-STAR are also possible.
Relativistic description of single-particle resonances via phase shift analysis
ZHANG Zi-Zhen
2009-01-01
Single-particle resonant states in spherical nuclei are studied by the real stabilization method in coordinate space within the framework of self-consistent relativistic mean field theory. Taking 122Zr as an example, the resonant parameters, including the energies and widths are extracted by fitting energy and phase shift. Good agreement with the previous calculations has been found. The details of single-particle resonant states are analysed.
Magnetic Field Generation and Particle Energization in Relativistic Shear Flows
Liang, Edison; Boettcher, Markus; Smith, Ian
2012-10-01
We present Particle-in-Cell simulation results of magnetic field generation by relativistic shear flows in collisionless electron-ion (e-ion) and electron-positron (e+e-) plasmas. In the e+e- case, small current filaments are first generated at the shear interface due to streaming instabilities of the interpenetrating particles from boundary perturbations. Such current filaments create transverse magnetic fields which coalesce into larger and larger flux tubes with alternating polarity, eventually forming ordered flux ropes across the entire shear boundary layer. Particles are accelerated across field lines to form power-law tails by semi-coherent electric fields sustained by oblique Langmuir waves. In the e-ion case, a single laminar slab of transverse flux rope is formed at the shear boundary, sustained by thin current sheets on both sides due to different drift velocities of electrons and ions. The magnetic field has a single polarity for the entire boundary layer. Electrons are heated to a fraction of the ion energy, but there is no evidence of power-law tail forming in this case.
On transition of propagation of relativistic particles from the ballistic to the diffusion regime
Prosekin, A Y; Aharonian, F A
2015-01-01
A stationary distribution function that describes the entire processes of propagation of relativistic particles, including the transition between the ballistic and diffusion regimes, is obtained. The spacial component of the constructed function satisfies to the first two moments of the Boltzmann equation. The angular part of the distribution provides accurate values for the angular moments derived from the Boltzmann equation, and gives a correct expression in the limit of small-angle approximation. Using the derived function, we studied the gamma-ray images produced through the $pp$ interaction of relativistic particles with gas clouds in the proximity of the accelerator. In general, the morphology and the energy spectra of gamma-rays significantly deviate from the "standard" results corresponding to the propagation of relativistic particles strictly in the diffusion regime.
On relativistic particle creation in Bose-Einstein condensates
Sabín, Carlos
2014-01-01
We show that particle creation of Bogoliubov modes in a Bose-Einstein condensate due to the accelerated motion of the trap is a genuinely relativistic effect. To this end we show that Bogoliubov modes can be described by a time rescaling of the Minkowski metric. A consequence of this is that Rindler transformations are perceived by the phonons as generalised Rindler transformations where the speed of light is replaced by the speed of sound, enhancing particle creation at small velocities. Since the non-relativistic limit of a Rindler transformation is just a Galilean transformation entailing no length contraction or time dilation, we show that the effect vanishes in the non-relativistic limit.
Relativistic formulations with Blankenbecler-Sugar reduction technique for the three-particle system
Morioka, S.; Afnan, I.R.
1981-02-01
We present a critical comparison for two types of three-dimensional covariant equations for the three-particle system obtained by the Blankenbecler-Sugar reduction technique with the Wightman-Garding momenta and the usual Jacobi variables. We also discuss the relations between the relativistic and nonrelativistic equations in the low-energy limit.
Zhu, Shi-Liang; Zhang, Dan-Wei; Wang, Z D
2009-05-29
We study theoretically the localization of relativistic particles in disordered one-dimensional chains. It is found that the relativistic particles tend to delocalization in comparison with the nonrelativistic particles with the same disorder strength. More intriguingly, we reveal that the massless Dirac particles are entirely delocalized for any energy due to the inherent chiral symmetry, leading to a well-known result that particles are always localized in one-dimensional systems for arbitrary weak disorders to break down. Furthermore, we propose a feasible scheme to detect the delocalization feature of the Dirac particles with cold atoms in a light-induced gauge field.
Reparametrization of the Relativistic Infinitely Extended Charged Particle Action
Saadat, Hassan; Pourhassan, Behnam
2016-09-01
In this letter, relativistic infinitely extended particles formulated. Correct form of action with possibility of reparametrization obtained and effect of electric field considered. It may be one of the first step to re-introduce theory of every things given by Nakano and Hessaby many years ago.
Particle Acceleration in Relativistic Electron-Ion Outlfows
Lloyd-Ronning, Nicole M
2016-01-01
We use the Los Alamos VPIC code to investigate particle acceleration in relativistic, unmagnetized, collisionless electron-ion plasmas. We run our simulations both with a realistic proton-to-electron mass ratio m_p/m_e = 1836, as well as commonly employed mass ratios of m_p/m_e =100 and 25, and show that results differ among the different cases. In particular, for the physically accurate mass ratio, electron acceleration occurs efficiently in a narrow region of a few hundred inertial lengths near the flow front, producing a power law dN/dgamma ~ gamma^(-p) with p ~ -2 developing over a few decades in energy, while acceleration is weak in the region far downstream. We find 20%, 10%, and 0.2% of the total energy given to the electrons for mass ratios of 25, 100, and 1836 respectively at a time of 2500 (w_p)^-1. Our simulations also show significant magnetic field generation just ahead of and behind the the flow front, with about 1% of the total energy going into the magnetic field for a mass ratio of 25 and 100...
Pondermotive acceleration of charged particles along the relativistic jets of an accreting blackhole
Ebisuzaki, T.; Tajima, T.
2014-05-01
Accreting blackholes such as miniquasars and active galactic nuclei can contribute to the highest energy components of intra- (˜1015 eV) galactic and extra-galactic components (˜1020 eV) of cosmic rays. Alfven wave pulses which are excited in the accretion disk around blackholes propagate in relativistic jets. Because of their highly non-linear nature of the waves, charged particles (protons, ions, and electrons) can be accelerated to high energies in relativistic jets in accreting blackhole systems, the central engine of miniquasars and active galactic nuclei.
Hussain, Nur; Bhattacharjee, Buddhadeb
2017-08-01
Widths of the rapidity distributions of various identified hadrons generated with the UrQMD-3.4 event generator at all the Super Proton Synchrotron (SPS) energies have been presented and compared with the existing experimental results. An increase in the width of the rapidity distribution of Λ could be seen with both Monte Carlo (MC) and experimental data for the studied energies. Using MC data, the study has been extended to Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies. A similar jump, as observed in the plot of rapidity width versus rest mass at Alternating Gradient Synchrotron (AGS) and all SPS energies, persists even at RHIC and LHC energies, confirming its universal nature from AGS to the highest LHC energies. Such observation indicates that pair production may not be the only mechanism of particle production at the highest LHC energies. However, with MC data, the separate mass scaling for mesons and baryons is found to exist even at the top LHC energy.
Microscopic Processes On Radiation from Accelerated Particles in Relativistic Jets
Nishikawa, K.-I.; Hardee, P. E.; Mizuno, Y.; Medvedev, M.; Zhang, B.; Sol, H.; Niemiec, J.; Pohl, M.; Nordlund, A.; Fredriksen, J.;
2009-01-01
Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., gamma-ray bursts (GRBs), active galactic nuclei (AGNs), and Galactic microquasar systems usually have power-law emission spectra. Recent PIC simulations of relativistic electron-ion (electro-positron) jets injected into a stationary medium show that particle acceleration occurs within the downstream jet. In the collisionless relativistic shock particle acceleration is due to plasma waves and their associated instabilities (e.g., the Buneman instability, other two-streaming instability, and the Weibel (filamentation) instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electron's transverse deflection behind the jet head. The jitter'' radiation from deflected electrons has different properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation may be important to understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants.
Formation of hard power laws in the energetic particle spectra resulting from relativistic magnetic reconnection.
Guo, Fan; Li, Hui; Daughton, William; Liu, Yi-Hsin
2014-10-10
Using fully kinetic simulations, we demonstrate that magnetic reconnection in relativistic plasmas is highly efficient at accelerating particles through a first-order Fermi process resulting from the curvature drift of particles in the direction of the electric field induced by the relativistic flows. This mechanism gives rise to the formation of hard power-law spectra in parameter regimes where the energy density in the reconnecting field exceeds the rest mass energy density σ ≡ B(2)/(4πnm(e)c(2))>1 and when the system size is sufficiently large. In the limit σ ≫ 1, the spectral index approaches p = 1 and most of the available energy is converted into nonthermal particles. A simple analytic model is proposed which explains these key features and predicts a general condition under which hard power-law spectra will be generated from magnetic reconnection.
Super revivals of a slightly relativistic particle in a box
Ghosh, Suranjana
2010-01-01
The time evolution of a particle, caught in an infinitely deep square well, is an apparently well studied and understood subject. However, unexpected features emerge, when one includes small relativistic effects. Indeed, even the smallest corrections to the nonrelativistic quadratic spectrum manifest themselves in a dramatic way. Our theoretical analysis brings to light a completely new time scale, at which the system exhibits surprisingly perfect revivals. This longer time scale rules the system dynamics and replaces the original revival time of the unperturbed system. We investigate the role and the interplay between these two time scales in the slightly relativistic case. Moreover, the examination of sub-Planck structures in phase space allows us to compare the finest details of wave packet dynamics for different values of the relativistic corrections.
Auxiliary fields in the geometrical relativistic particle dynamics
Amador, A; Bagatella, N; Rojas, E [Departamento de Fisica, Facultad de Fisica e Inteligencia Artificial, Universidad Veracruzana, 91000 Xalapa, Veracruz (Mexico); Cordero, R [Departamento de Fisica, Escuela Superior de Fisica y Matematicas del I.P.N, Edificio 9, 07738 Mexico D.F (Mexico)], E-mail: aramador@gmail.com, E-mail: nbagatella@uv.mx, E-mail: cordero@esfm.ipn.mx, E-mail: efrojas@uv.mx
2008-03-21
We describe how to construct the dynamics of relativistic particles, following either timelike or null curves, by means of an auxiliary variables method instead of the standard theory of deformations for curves. There are interesting physical particle models governed by actions that involve higher order derivatives of the embedding functions of the worldline. We point out that the mechanical content of such models can be extracted wisely from a lower order action, which can be performed by implementing in the action a finite number of constraints that involve the geometrical relationship structures inherent to a curve and by using a covariant formalism. We emphasize our approach for null curves. For such systems, the natural time parameter is a pseudo-arclength whose properties resemble those of the standard proper time. We illustrate the formalism by applying it to some models for relativistic particles.
A Signed Particle Formulation of Non-Relativistic Quantum Mechanics
Sellier, Jean Michel
2015-01-01
A formulation of non-relativistic quantum mechanics in terms of Newtonian particles is presented in the shape of a set of three postulates. In this new theory, quantum systems are described by ensembles of signed particles which behave as field-less classical objects which carry a negative or positive sign and interact with an external potential by means of creation and annihilation events only. This approach is shown to be a generalization of the signed particle Wigner Monte Carlo method which reconstructs the time-dependent Wigner quasi-distribution function of a system and, therefore, the corresponding Schroedinger time-dependent wave-function. Its classical limit is discussed and a physical interpretation, based on experimental evidences coming from quantum tomography, is suggested. Moreover, in order to show the advantages brought by this novel formulation, a straightforward extension to relativistic effects is discussed. To conclude, quantum tunnelling numerical experiments are performed to show the val...
Particle Acceleration in Relativistic Jets Due to Weibel Instability
Nishikawa, K.-I.; Hardee, P.; Richardson, G.; Preece, R.; Sol, H.; Fishman, G. J.
2004-01-01
Shock acceleration is a ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, two-streaming instability, and the Weibel instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. Using a three-dimensional relativistic electromagnetic particle code, we have investigated particle acceleration associated with a relativistic jet front propagating through an ambient plasma with and without initial magnetic fields. We find only small differences in the results between no ambient and weak ambient magnetic fields. Simulations show that the Weibel instability created in the collisionless shock front accelerates particles perpendicular and parallel to the jet propagation direction. While some Fermi acceleration may occur at the jet front, the majority of electron acceleration takes place behind the jet front and cannot be characterized as Fermi acceleration. The simulation results show that this instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields, which contribute to the electron s transverse deflection behind the jet head. The "jitter" radiation from deflected electrons has different properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation may be important to understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants.
Particle dynamics in a relativistic invariant stochastic medium
Cabo-Bizet, A; Cabo-Bizet, Alejandro; Oca, Alejandro Cabo Montes de
2005-01-01
The dynamics of particles moving in a medium defined by its relativistically invariant stochastic properties is investigated. For this aim, the force exerted on the particles by the medium is defined by a stationary random variable as a function of the proper time of the particles. The equations of motion for a single one-dimensional particle are obtained and numerically solved. A conservation law for the drift momentum of the particle during its random motion is shown. Moreover, the conservation of the mean value of the total linear momentum for two particles repelling each other according with the Coulomb interaction is also following. Therefore, the results indicate the realization of a kind of stochastic Noether theorem in the system under study. Possible applications to the stochastic representation of Quantum Mechanics are advanced.
Particle dynamics in a relativistic invariant stochastic medium
Cabo-Bizet, Alejandro [Facultad de Fisica, Universidad de La Habana, Colina Universitaria, Havana (Cuba); Cabo Montes de Oca, Alejandro [Grupo de Fisica Teorica, Instituto de Cibernetica, Matematica y Fisica, Havana (Cuba) and Abdus Salam International Center for Theoretical Physics, Strada Costiera 11, Miramare, Trieste (Italy)]. E-mail: cabo@fis.puc.cl
2006-11-27
The dynamics of particles moving in a medium defined by its relativistically invariant stochastic properties is investigated. For this aim, the force exerted on the particles by the medium is defined by a stationary random variable as a function of the proper time of the particles. The equations of motion for a single one-dimensional particle are obtained and numerically solved. A conservation law for the drift momentum of the particle during its random motion is shown. Moreover, the conservation of the mean value of the total linear momentum for two particles repelling each other according to the Coulomb interaction also follows. Therefore, the results indicate the realization of a kind of stochastic Noether theorem in the system under study.
General Relativistic Smoothed Particle Hydrodynamics code developments: A progress report
Faber, Joshua; Silberman, Zachary; Rizzo, Monica
2017-01-01
We report on our progress in developing a new general relativistic Smoothed Particle Hydrodynamics (SPH) code, which will be appropriate for studying the properties of accretion disks around black holes as well as compact object binary mergers and their ejecta. We will discuss in turn the relativistic formalisms being used to handle the evolution, our techniques for dealing with conservative and primitive variables, as well as those used to ensure proper conservation of various physical quantities. Code tests and performance metrics will be discussed, as will the prospects for including smoothed particle hydrodynamics codes within other numerical relativity codebases, particularly the publicly available Einstein Toolkit. We acknowledge support from NSF award ACI-1550436 and an internal RIT D-RIG grant.
Particle transport in microturbulence and acceleration performances of relativistic shocks
Plotnikov, Illya; Lemoine, Martin
2012-01-01
Collisionless relativistic shocks have been the focus of intense theoretical and numerical investigations and these interesting physics have a direct impact on the generation of energetic particles and the interpretation of gamma ray spectra. The Fermi acceleration process that takes place in these shocks is intimately linked with the excitation of micro-turbulence responsible for the shock formation, electron heating and supra-thermal tail generation that in turn excites micro-turbulence, developing thus a self-sustaining phenomenon. In this paper we discuss the development of the micro-turbulence and we investigate two important issues: firstly the transport of supra-thermal particles in the excited microturbulence upstream of the shock and its consequences for the efficiency of the Fermi process; secondly, the preheating process of the incoming background electrons as they cross the shock precursor and experience relativistic oscillations in the electric field of the micro-turbulence.We emphasize the impor...
Derivation of the classical lagrangian for the relativistic spinning particle
Cho, J; Jin-Ho Cho; Jae-Kwan Kim
1994-01-01
The `classical' model for a massive spinning particle, which was recently proposed, is derived from the isotropic rotator model. Through this derivation, we note that the spin can be understood as the relativistic extension of the isotropic rotator. Furthermore, the variables t_\\m corresponding to the \\p^* of the `pseudo-classical' model, are necessary for the covariant formulation. The dynamical term for these extra variables is naturally obtained and the meaning of the constraint term p^\\s\\L_{\\s\
Surveying relativistic entanglement of two particles with continuous momenta
Palge, Veiko; Dunningham, Jacob
2014-01-01
In this paper we explore the entanglement of two relativistic spin-$1/2$ particles with continuous momenta. The spin state is described by the Bell state and the momenta are given by Gaussian distributions of product and entangled form. Transformations of the spins are systematically investigated in different boost scenarios by calculating the orbits and concurrence of the spin degree of freedom. By visualizing the behavior of the spin state we get further insight into how and why the entangl...
On origin and destruction of relativistic dust and its implication for ultrahigh energy cosmic rays
Hoang, Thiem; Schlickeiser, R
2014-01-01
Dust grains may be accelerated to relativistic speeds by radiation pressure of luminous sources, diffusive shocks, and other acceleration mechanisms. Such relativistic grains have been suggested as potential primary particles of ultrahigh energy cosmic rays (UHECRs). In this paper, we reexamine this idea by studying in detail different destruction mechanisms for relativistic grains moving with Lorentz factor $\\gamma$ through a variety of environment conditions. For the solar radiation field, we find that sublimation/melting is a dominant destruction mechanism for silicate grains and large graphite grains. Using an improved treatment of photoelectric emission, we calculate the closest distance that relativistic grains can approach the Sun before destroyed by Coulomb explosions. A range of survival parameters for relativistic grains (size $a$ and $\\gamma$) against both sublimation and Coulomb explosions by the solar radiation field is identified. We also study collisional destruction mechanisms, consisting of e...
Higher-order perturbative relativistic corrections to energies and properties
Stopkowicz, Stella
2011-01-01
Relativistic effects need to be considered in quantum-chemical calculations on systems including heavy elements or when aiming at high accuracy for molecules containing only lighter elements. In the latter case, consideration of relativistic effects via perturbation theory is an attractive option. Among the available techniques, Direct Perturbation Theory (DPT) in its lowest order (DPT2) has become a standard tool for the calculation of relativistic corrections to energies and properties.In t...
Melzani, Mickaël; Folini, Doris; Winisdoerffer, Christophe; Favre, Jean M
2014-01-01
Magnetic reconnection is a leading mechanism for magnetic energy conversion and high-energy non-thermal particle production in a variety of high-energy astrophysical objects, including ones with relativistic ion-electron plasmas (e.g., microquasars or AGNs) - a regime where first principle studies are scarce. We present 2D particle-in-cell (PIC) simulations of low $\\beta$ ion-electron plasmas under relativistic conditions, i.e., with inflow magnetic energy exceeding the plasma rest-mass energy. We identify outstanding properties: (i) For relativistic inflow magnetizations (here $10 80$), the reconnection electric field is sustained more by bulk inertia than by thermal inertia. It challenges the thermal-inertia-paradigm and its implications. (iii) The inflows feature sharp transitions at the entrance of the diffusion zones. These are not shocks but results from particle ballistic motions, all bouncing at the same location, provided that the thermal velocity in the inflow is far smaller than the inflow E cross...
Holographic energy loss in non-relativistic backgrounds
Atashi, Mahdi; Farahbodnia, Mitra
2016-01-01
In this paper, we study some aspects of energy loss in non-relativistic theories from holography. We analyze the energy lost by a rotating heavy point particle along a circle of radius $l$ with angular velocity $\\omega$ in theories with general dynamical exponent $z$ and hyperscaling violation exponent $\\theta$. It is shown that this problem provides a novel perspective on the energy loss in such theories. A general computation at zero and finite temperature is done and it is shown that how the total energy loss rate depends non-trivially on two characteristic exponents $(z,\\theta)$. We find that at zero temperature there is a special radius $l_c$ where the energy loss is independent of different values of $(z,\\theta)$. Also, there is a crossover between a regime in which the energy loss is dominated by the linear drag force and by the radiation because of the acceleration of the rotating particle. We discover different behaviors at finite temperature case.
$\\Lambda$ polarization in peripheral collisions at moderate relativistic energies
Xie, Y L; Stöcker, H; Wang, D J; Csernai, L P
2016-01-01
The polarization of $\\Lambda$ hyperons from relativistic flow vorticity is studied in peripheral heavy ion reactions at FAIR and NICA energies, just above the threshold of the transition to the Quark-Gluon Plasma. Previous calculations at higher energies with larger initial angular momentum, predicted significant $\\Lambda$ polarization based on the classical vorticity term in the polarization, while relativistic modifications decreased the polarization and changed its structure in the momentum space. At the lower energies studied here, we see the same effect namely that the relativistic modifications decrease the polarization arising from the initial shear flow vorticity.
Relativistic Dirac Representation of Dynamically-Generated Elementary-Particle Mass
Chew, Geoffrey F
2008-01-01
Special-relativistic dynamically-generated elementary-particle mass is represented by a self-adjoint energy operator acting on a rigged Hilbert space (RHS) of functions over the 6-dimensional Euclidean-group manifold. Even though this operator's eigenvalues correspond to total energy, it is not the generator of infinitesimal wave-function evolution in classical time. Extending formalism which Dirac invented and applied non-relativistically, unitary Poincar\\'e-group representation is provided by the wave functions of a spacelike entity that we call "preon". Six continuous Feynman-path-contacting preon coordinates specify spatial location (3 coordinates), lightlike-velocity-direction (2 coordinates) and transverse polarization (1 coordinate). [Utility of the the term "preon observable" is dubious.] Velocity and spatial location collaborate to define a preon time operator conjugate to the energy operator. In RHS bases alternative to functions over the group manifold, the wave function depends on a preon "velocit...
A String Motivated Approach to the Relativistic Point Particle
Tuite, M P; Tuite, Michael; Sen, Siddhartha
2003-01-01
Using concepts developed in string theory, Cohen, Moore, Nelson and Polchinski calculated the propagator for a relativistic point particle. Following these authors we extend the technique to include the case of closed world lines. The partition function found corresponds to the Feynmann and Schwinger proper time formalism. We also explicitly verify that the partition function is equivalent to the usual path length action partition function. As an example of a sum over closed world lines, we compute the Euler-Heisenberg effective Lagrangian in a novel way.
Path integral polymer propagator of relativistic and non-relativistic particles
Morales-Técotl, Hugo A; Ruelas, Juan C
2016-01-01
A recent proposal to connect the loop quantization with the spin foam model for cosmology via the path integral is hereby adapted to the case of mechanical systems within the framework of the so called polymer quantum mechanics. The mechanical models we consider are deparametrized and thus the group averaging technique is used to deal with the corresponding constraints. The transition amplitudes are written in a vertex expansion form used in the spin foam models, where here a vertex is actually a jump in position. Polymer Propagators previously obtained by spectral methods for a nonrelativistic polymer particle, both free and in a box, are regained with this method. Remarkably, the approach is also shown to yield the polymer propagator of the relativistic particle. This reduces to the standard form in the continuum limit for which the length scale parameter of the polymer quantization is taken to be small. Some possible future developments are commented upon.
Zhevago, N. K.; Glebov, V. I.
2017-06-01
We have developed the theory of electromagnetic interaction of relativistic charged particles with metal-organic frameworks (MOFs). The electrostatic potential and electron number density distribution in MOFs were calculated using the most accurate data for the atomic form factors. Peculiarities of axial channeling of fast charged particles and various types of electromagnetic radiation from relativistic particles has been discussed.
On the energy conservation by weak solutions of the relativistic Vlasov-Maxwell system
Sospedra-Alfonso, Reinel
2010-01-01
We show that weak solutions of the relativistic Vlasov-Maxwell system preserve the total energy provided that the electromagnetic field is locally of bounded variation and, for any $\\lambda$> 0, the one-particle distribution function has a square integrable $\\lambda$-moment in the momentum variable.
Applying the relativistic quantization condition to a three-particle bound state in a periodic box
Hansen, Maxwell T.; Sharpe, Stephen R.
2017-02-01
Using our recently developed relativistic three-particle quantization condition [Phys. Rev. D 90, 116003 (2014), 10.1103/PhysRevD.90.116003; Phys. Rev. D 92, 114509 (2015), 10.1103/PhysRevD.92.114509], we study the finite-volume energy shift of a spin-zero three-particle bound state. We reproduce the result obtained using nonrelativistic quantum mechanics by Meißner et al. in [Phys. Rev. Lett. 114, 091602 (2015), 10.1103/PhysRevLett.114.091602] and generalize the result to a moving frame.
Nonthermal Particle Acceleration in 3D Relativistic Magnetic Reconnection in Pair Plasma
Werner, Gregory R.; Uzdensky, Dmitri A.
2017-07-01
As a fundamental process converting magnetic to plasma energy in high-energy astrophysical plasmas, relativistic magnetic reconnection is a leading explanation for the acceleration of particles to the ultrarelativistic energies that are necessary to power nonthermal emission (especially X-rays and gamma-rays) in pulsar magnetospheres and pulsar wind nebulae, coronae and jets of accreting black holes, and gamma-ray bursts. An important objective of plasma astrophysics is therefore the characterization of nonthermal particle acceleration (NTPA) effected by reconnection. Reconnection-powered NTPA has been demonstrated over a wide range of physical conditions using large 2D kinetic simulations. However, its robustness in realistic 3D reconnection—in particular, whether the 3D relativistic drift-kink instability (RDKI) disrupts NTPA—has not been systematically investigated, although pioneering 3D simulations have observed NTPA in isolated cases. Here, we present the first comprehensive study of NTPA in 3D relativistic reconnection in collisionless electron-positron plasmas, characterizing NTPA as the strength of 3D effects is varied systematically via the length in the third dimension and the strength of the guide magnetic field. We find that, while the RDKI prominently perturbs 3D reconnecting current sheets, it does not suppress particle acceleration, even for zero guide field; fully 3D reconnection robustly and efficiently produces nonthermal power-law particle spectra closely resembling those obtained in 2D. This finding provides strong support for reconnection as the key mechanism powering high-energy flares in various astrophysical systems. We also show that strong guide fields significantly inhibit NTPA, slowing reconnection and limiting the energy available for plasma energization, yielding steeper and shorter power-law spectra.
Unified relativistic physics from a standing wave particle model
Vera, R A
1995-01-01
An extremely simple and unified base for physics comes out by starting all over from a single postulate on the common nature of matter and stationary forms of radiation quanta. Basic relativistic, gravitational (G) and quantum mechanical properties of a standing wave particle model have been derived. This has been done from just dual properties of radiation's and strictly homogeneous relationships for nonlocal cases in G fields. This way reduces the number of independent variables and puts into relief (and avoid) important inhomogeneity errors of some G theories. It unifies and accounts for basic principles and postulates physics. The results for gravity depend on linear radiation properties but not on arbitrary field relations. They agree with the conventional tests. However they have some fundamental differences with current G theories. The particle model, at a difference of the conventional theories, also fixes well-defined cosmological and astrophysical models that are different from the rather convention...
Dark Energy Coupled with Relativistic Dark Matter in Accelerating Universe
张杨
2003-01-01
Recent observations favour an accelerating Universe dominated by the dark energy. We take the effective YangMills condensate as the dark energy and couple it to a relativistic matter which is created by the decaying condensate. The dynamic evolution has asymptotic behaviour with finite constant energy densities, and the fractional densities Ω∧～ 0.7 for dark energy and Ωm ～ 0.3 for relativistic matter are achieved at proper values of the decay rate. The resulting expansion of the Universe is in the de Sitter acceleration.
Particle production and nonlinear diffusion in relativistic systems
Wolschin, Georg
2008-01-01
The short parton production phase in high-energy heavy-ion collisions is treated analytically as a nonlinear diffusion process. The initial buildup of the rapidity density distributions of produced charged hadrons within tau_p = 0.25 fm/c occurs in three sources during the colored partonic phase. In a two-step approach, the subsequent diffusion in pseudorapidity space during the interaction time of tau_int = 7-10 fm/c (mean duration of the collision) is essentially linear as expressed in the Relativistic Diffusion Model (RDM) which yields excellent agreement with the data at RHIC energies, and allows for predictions at LHC energies. Results for d+Au are discussed in detail.
Dodin, I Y; Fraiman, G M
2003-01-01
The Lagrangian and Hamiltonian functions describing average motion of a relativistic particle under the action of intensive high-frequency electromagnetic radiation are obtained. In weak, low-frequency background fields, such a particle on average drifts with an effective, relativistically invariant mass, which depends on the intensity of the electromagnetic field.
Fundamental channeling questions at ultra relativistic energies
Carrigan, Richard A., Jr.; /Fermilab
2006-08-01
TeV-range bent crystal channeling has interesting advantages for several applications at high energy accelerators. Observations of enhanced deflection over the whole arc of a bent crystal at RHIC and recently at the Tevatron may be due to a process called ''volume reflection''. More investigations of volume reflection and of the complimentary process, volume capture, are needed. So-called quasimosaic bending processes also deserve additional study. Negative particle channeling may be relevant to channeling collimation for electron machines. Electron and positron channeling and channeling radiation are interwoven so that the impact of channeling radiation on applications needs to be better understood. Beams in the 0.1 to 1 GeV range may be useful for some of these investigations. Finally there has been little or no study of positive and negative muon channeling. The current understanding of these topics and the desirability of further work is reviewed.
Collisionless Relativistic Shocks:current driven turbulence and particle acceleration
Pelletier, Guy; Gremillet, Laurent; Plotnikov, Illya
2014-01-01
The physics of collisionless relativistic shocks with a moderate magnetization is presented. Micro-physics is relevant to explain the most energetic radiative phenomena of Nature, namely that of the termination shock of Gamma Ray Bursts. A transition towards Fermi process occurs for decreasing magnetization around a critical value which turns out to be the condition for the scattering to break the mean field inhibition. Scattering is produced by magnetic micro-turbulence driven by the current carried by returning particles, which had not been considered till now, but turns out to be more intense than Weibel's one around the transition. The current is also responsible for a buffer effect on the motion of the incoming flow, on which the threshold for the onset of turbulence depends.
Melzani, Mickaël; Folini, Doris; Winisdoerffer, Christophe; Favre, Jean M
2014-01-01
Collisionless magnetic reconnection is a prime candidate to account for flare-like or steady emission, outflow launching, or plasma heating, in a variety of high-energy astrophysical objects, including ones with relativistic ion-electron plasmas. But the fate of the initial magnetic energy in a reconnection event remains poorly known: what is the amount given to kinetic energy, the ion/electron repartition, and the hardness of the particle distributions? We explore these questions with 2D particle-in-cell simulations of ion-electron plasmas. We find that 45 to 75% of the total initial magnetic energy ends up in kinetic energy, this fraction increasing with the inflow magnetization. Depending on the guide field strength, ions get from 30 to 60% of the total kinetic energy. Particles can be separated into two populations that only weakly mix: (i) particles initially in the current sheet, heated by its initial tearing and subsequent contraction of the islands; and (ii) particles from the background plasma that p...
Werner, G R; Cerutti, B; Nalewajko, K; Begelman, M C
2014-01-01
Using two-dimensional particle-in-cell simulations, we characterize the energy spectra of particles accelerated by relativistic magnetic reconnection (without guide field) in collisionless electron-positron plasmas, for a wide range of upstream magnetizations $\\sigma$ and system sizes $L$. The particle spectra are well-represented by a power law $\\gamma^{-\\alpha}$, with a combination of exponential and super-exponential high-energy cutoffs, proportional to $\\sigma$ and $L$, respectively. For large $L$ and $\\sigma$, the power-law index $\\alpha$ approaches about 1.2.
Energy shift of interacting non-relativistic fermions in noncommutative space
A. Jahan
2005-06-01
Full Text Available A local interaction in noncommutative space modifies to a non-local one. For an assembly of particles interacting through the contact potential, formalism of the quantum field theory makes it possible to take into account the effect of modification of the potential on the energy of the system. In this paper we calculate the energy shift of an assembly of non-relativistic fermions, interacting through the contact potential in the presence of the two-dimensional noncommutativity.
Zhou Dai Mei; Sá Ben-Hao; Li Zhong Dao
2002-01-01
Using a hadron and string cascade model, JPCIAE, and the corresponding Monte Carlo events generator, the energy and centrality dependences of charged particle pseudorapidity density in relativistic nuclear collisions were studied. Within the framework of this model, both the relativistic p anti p experimental data and the PHOBOS and PHENIX Au + Au data could be reproduced fairly well without retuning the model parameters. The author shows that since is not a well defined physical variable both experimentally and theoretically, the charged particle pseudorapidity density per participant pair can increase and also can decrease with increasing of , so it may be hard to use charged particle pseudorapidity density per participant pair as a function of to distinguish various theoretical models for particle production
Nucleon self-energy in the relativistic Brueckner theory
Waindzoch, T.; Fuchs, C.; Faessler, A. [Inst. fuer Theoretische Physik, Univ. Tuebingen (Germany)
1998-06-01
The self-energy of the nucleon in nuclear matter is calculated in the relativistic Brueckner theory. We solve the Thompson equation for the two nucleon scattering in the medium using different Bonn potentials. The self-energy has a rather strong momentum dependence while the equation of state compares well with previous calculations. (orig.)
The extent of non-thermal particle acceleration in relativistic, electron-positron reconnection
Werner, Greg [University of Colorado; Guo, Fan [Los Alamos National Laboratory
2015-07-21
Reconnection is studied as an explanation for high-energy flares from the Crab Nebula. The production of synchrotron emission >100 MeV challenges classical models of acceleration. 3D simulation shows that reconnection, converting magnetic energy to kinetic energy, can accelerate beyond γ_{rad}. The power-law index and high-energy cutoff are important for understanding the radiation spectrum dN/dγ = f(γ) ∝ γ^{-α}. α and cutoff were measured vs. L and σ, where L is system (simulation) size and σ is upstream magnetization (σ = B^{2}/4πnmc^{2}). α can affect the high-energy cutoff. In conclusion, for collisionless relativistic reconnection in electron-positron plasma, without guide field, n_{b}/n_{d}=0.1: (1) relativistic magnetic reconnection yields power-law particle spectra, (2) the power law index decreases as σ increases, approaching ≈1.2. (3) the power law is cut off at an energy related to acceleration within a single current layer, which is proportional to the current layer length (for small systems, that length is the system length, yielding γ_{c2} ≈ 0.1 L/ρ_{0}; for large systems, the layer length is limited by secondary tearing instability, yielding γ_{c1} ≈ 4σ; the transition from small to large is around L/ρ_{0} = 40σ.). (4) although the large-system energy cutoff is proportional to the average energy per particle, it is significantly higher than the average energy per particle.
Thermodynamics of relativistic Newton—Wigner particle in external potential field
Larkin, A. S.; Filinov, V. S.
2015-11-01
Thermodynamic properties of relativistic spinless particle described by the Klein-Gordon equation have been studied using the Newton-Wigner theory of particle in external potential field. Concept of Wiener path integral was extended on relativistic case. A new path integral Monte-Carlo method was developed for relativistic particle in external potential field. The bounds of applicability of available analytical approaches and related results have been specified by comparison with Monte-Carlo calculations. Developed path integral formalism can be directly extended on systems of many identical Newton-Wigner particles, which interact with external field and each other.
THEORETICAL CALCULATION OF THE RELATIVISTIC SUBCONFIGURATION-AVERAGED TRANSITION ENERGIES
张继彦; 杨向东; 杨国洪; 张保汉; 雷安乐; 刘宏杰; 李军
2001-01-01
A method for calculating the average energies of relativistic subconfigurations in highly ionized heavy atoms has been developed in the framework of the multiconfigurational Dirac-Fock theory. The method is then used to calculate the average transition energies of the spin-orbit-split 3d-4p transition of Co-like tungsten, the 3d-5f transition of Cu-like tantalum, and the 3d-5f transitions of Cu-like and Zn-like gold samples. The calculated results are in good agreement with those calculated with the relativistic parametric potential method and also with the experimental results.
Convex Decompositions of Thermal Equilibrium for Non-interacting Non-relativistic Particles
Chenu, Aurelia; Branczyk, Agata; Sipe, John
2016-05-01
We provide convex decompositions of thermal equilibrium for non-interacting non-relativistic particles in terms of localized wave packets. These quantum representations offer a new tool and provide insights that can help relate to the classical picture. Considering that thermal states are ubiquitous in a wide diversity of fields, studying different convex decompositions of the canonical ensemble is an interesting problem by itself. The usual classical and quantum pictures of thermal equilibrium of N non-interacting, non-relativistic particles in a box of volume V are quite different. The picture in classical statistical mechanics is about (localized) particles with a range of positions and velocities; in quantum statistical mechanics, one considers the particles (bosons or fermions) associated with energy eigenstates that are delocalized through the whole box. Here we provide a representation of thermal equilibrium in quantum statistical mechanics involving wave packets with a localized coordinate representation and an expectation value of velocity. In addition to derive a formalism that may help simplify particular calculations, our results can be expected to provide insights into the transition from quantum to classical features of the fully quantum thermal state.
Investigation of rare particle production in relativistic heavy ion collisions
Crawford, H.J.; Engelage, J.
1991-01-01
During FY91 we began our investigation of rare particle production in relativistic nuclear collisions at the Brookhaven National Laboratory. We were funded for a period of one year to perform the initial experimental search, E858, to determine the level of antideuteron ({bar d}) production in Si+Au collisions at the AGS. We accomplished this goal with the discovery of two {bar d}'s in the June 1990 run. We describe in this paper experiment performed and the results obtained. We performed our rare particle search at the A-1 line of the AGS. We instrumented the line with a four time-of-flight (TOF) detectors, two high pressure gas Cerenkox (ck) detectors, and four drift tube (DT) tracking detectors. The TOF detectors achieved time resolution of better than 100ps leading to a mass resolution of <15 MeV at 1 GeV. The Ck detectors were used both to suppress the large {pi}{sup {minus}} signal and in {pi}/K separation at high rigidities. The DT system provided particle trajectories for all of the particles passing the trigger requirements. In this experiment we measured the {pi}{sup {minus}}, K-, and {bar p} momentum spectra at 0{sup o} for rigidities from 2 to 8 GV to a statistical accuracy of 1--3% at all settings. We found that the {bar p} yield as a function of target did not show any evidence for reabsorption within the interaction volume. We also found two {bar d}'s, the first observation of complex antinuclei produced in nucleus-nucleus collisions. The {bar d} yield is at least an order of magnitude smaller than prediced using a simple coalescence model based on the d/p ratio from E802 and the {bar p} spectrum measured in our experiment.
Simulations of Relativistic Collisionless Shocks: Shock Structure and Particle Acceleration
Spitkovsky, Anatoly; /KIPAC, Menlo Park
2006-04-10
We discuss 3D simulations of relativistic collisionless shocks in electron-positron pair plasmas using the particle-in-cell (PIC) method. The shock structure is mainly controlled by the shock's magnetization (''sigma'' parameter). We demonstrate how the structure of the shock varies as a function of sigma for perpendicular shocks. At low magnetizations the shock is mediated mainly by the Weibel instability which generates transient magnetic fields that can exceed the initial field. At larger magnetizations the shock is dominated by magnetic reflections. We demonstrate where the transition occurs and argue that it is impossible to have very low magnetization collisionless shocks in nature (in more than one spatial dimension). We further discuss the acceleration properties of these shocks, and show that higher magnetization perpendicular shocks do not efficiently accelerate nonthermal particles in 3D. Among other astrophysical applications, this may pose a restriction on the structure and composition of gamma-ray bursts and pulsar wind outflows.
Energy Extraction from Spinning Black Holes via Relativistic Jets
Narayan, Ramesh; Tchekhovskoy, Alexander
2013-01-01
It has for long been an article of faith among astrophysicists that black hole spin energy is responsible for powering the relativistic jets seen in accreting black holes. Two recent advances have strengthened the case. First, numerical general relativistic magnetohydrodynamic simulations of accreting spinning black holes show that relativistic jets form spontaneously. In at least some cases, there is unambiguous evidence that much of the jet energy comes from the black hole, not the disk. Second, spin parameters of a number of accreting stellar-mass black holes have been measured. For ballistic jets from these systems, it is found that the radio luminosity of the jet correlates with the spin of the black hole. This suggests a causal relationship between black hole spin and jet power, presumably due to a generalized Penrose process.
Caprioli, Damiano
2014-01-01
We use large hybrid (kinetic ions-fluid electrons) simulations to study ion acceleration and generation of magnetic turbulence due to the streaming of energetic particles that are self-consistently accelerated at non-relativistic shocks. When acceleration is efficient (at quasi-parallel shocks), we find that the magnetic field develops transverse components and is significantly amplified in the pre-shock medium. The total amplification factor is larger than 10 for shocks with Mach number $M=100$, and scales with the square root of $M$. We find that in the shock precursor the energy spectral density of excited magnetic turbulence is proportional to spectral energy distribution of accelerated particles at corresponding resonant momenta, in good agreement with the predictions of quasilinear theory of diffusive shock acceleration. We discuss the role of Bell's instability, which is predicted and found to grow faster than resonant instability in shocks with $M\\gtrsim 30$. Ahead of these strong shocks we distinguis...
Relativistic Reconnection: an Efficient Source of Non-Thermal Particles
Sironi, Lorenzo
2014-01-01
In magnetized astrophysical outflows, the dissipation of field energy into particle energy via magnetic reconnection is often invoked to explain the observed non-thermal signatures. By means of two- and three-dimensional particle-in-cell simulations, we investigate anti-parallel reconnection in magnetically-dominated electron-positron plasmas. Our simulations extend to unprecedentedly long temporal and spatial scales, so we can capture the asymptotic state of the system beyond the initial transients, and without any artificial limitation by the boundary conditions. At late times, the reconnection layer is organized into a chain of large magnetic islands connected by thin X-lines. The plasmoid instability further fragments each X-line into a series of smaller islands, separated by X-points. At the X-points, the particles become unmagnetized and they get accelerated along the reconnection electric field. We provide definitive evidence that the late-time particle spectrum integrated over the whole reconnection r...
Nalewajko, Krzysztof [Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Stanford University, 2575 Sand Hill Road M/S 29, Menlo Park, CA 94025 (United States); Uzdensky, Dmitri A.; Werner, Gregory R. [Center for Integrated Plasma Studies, Physics Department, University of Colorado, UCB 390, Boulder, CO 80309-0390 (United States); Cerutti, Benoit [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Begelman, Mitchell C., E-mail: knalew@stanford.edu [JILA, University of Colorado and National Institute of Standards and Technology, 440 UCB, Boulder, CO 80309 (United States)
2015-12-20
We investigate the distribution of particle acceleration sites, independently of the actual acceleration mechanism, during plasmoid-dominated, relativistic collisionless magnetic reconnection by analyzing the results of a particle-in-cell numerical simulation. The simulation is initiated with Harris-type current layers in pair plasma with no guide magnetic field, negligible radiative losses, no initial perturbation, and using periodic boundary conditions. We find that the plasmoids develop a robust internal structure, with colder dense cores and hotter outer shells, that is recovered after each plasmoid merger on a dynamical timescale. We use spacetime diagrams of the reconnection layers to probe the evolution of plasmoids, and in this context we investigate the individual particle histories for a representative sample of energetic electrons. We distinguish three classes of particle acceleration sites associated with (1) magnetic X-points, (2) regions between merging plasmoids, and (3) the trailing edges of accelerating plasmoids. We evaluate the contribution of each class of acceleration sites to the final energy distribution of energetic electrons: magnetic X-points dominate at moderate energies, and the regions between merging plasmoids dominate at higher energies. We also identify the dominant acceleration scenarios, in order of decreasing importance: (1) single acceleration between merging plasmoids, (2) single acceleration at a magnetic X-point, and (3) acceleration at a magnetic X-point followed by acceleration in a plasmoid. Particle acceleration is absent only in the vicinity of stationary plasmoids. The effect of magnetic mirrors due to plasmoid contraction does not appear to be significant in relativistic reconnection.
Charged-particle multiplicity at mid-rapidity in Au–Au collisions at relativistic heavy-ion collider
D Silvermyr
2003-05-01
The particle density at mid-rapidity is an essential global variable for the characterization of nuclear collisions at ultra-relativistic energies. It provides information about the initial conditions and energy density reached in these collisions. The pseudorapidity densities of charged particles at mid-rapidity in Au + Au collisions at $\\sqrt{S_{NN}}=130$ and 200 GeV at RHIC (relativistic heavy ion collider) have been measured with the PHENIX detector. The measurements were performed using sets of wire-chambers with pad readout in the two central PHENIX tracking arms. Each arm covers one quarter of the azimuth in the pseudorapidity interval || < 0.35. Data is presented and compared with results from proton–proton collisions and nucleus–nucleus collisions at lower energies. Extrapolations to LHC energies are discussed.
Charged-particle multiplicity at mid-rapidity in Au-Au collisions at relativistic heavy-ion collider
Silvermyr, D
2003-01-01
The particle density at mid-rapidity is an essential global variable for the characterization of nuclear collisions at ultra-relativistic energies. It provides information about the initial conditions and energy density reached in these collisions. The pseudorapidity densities of charged particles at mid-rapidity in Au+Au collisions at root s//N//N = 130 and 200 GeV at RHIC (relativistic heavy ion collider) have been measured with the PHENIX detector. The measurements were performed using sets of wire-chambers with pad readout in the two central PHENIX tracking arms. Each arm covers one quarter of the azimuth in the pseudorapidity interval vertical bar eta vertical bar less than 0.35. Data is presented and compared with results from proton-proton collisions and nucleus-nucleus collisions at lower energies. Extrapolations to LHC energies are discussed. 16 Refs.
Losing energy in classical, relativistic and quantum mechanics
Atkinson, David
2007-01-01
A Zenonian supertask involving an infinite number of colliding balls is considered, under the restriction that the total mass of all the balls is finite. Classical mechanics leads to the conclusion that momentum, but not necessarily energy, must be conserved. In relativistic mechanics, however, neit
Relativistic energies for the SiC radical
Jia, Chun-Sheng [Southwest Petroleum University, State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu (China); Shui, Zheng-Wei [Southwest Petroleum University, School of Vocational and Technical Education, Nanchong (China)
2015-11-15
The analytical solutions of the Dirac equation with the modified Rosen-Morse potential energy model have been explored. Under the condition of the spin symmetry, we present the bound state energy equation. In the nonrelativistic limit, the relativistic energy equation becomes the nonrelativistic energy form deduced within the framework of the Schroedinger equation. We find that the relativistic effect of the relative motion of the ions leads to a little decrease in the vibrational energies when the vector potential is equal to the scalar potential for the electronic ground state of the SiC radical, while to an increase in those if the vector potential is greater than the scalar potential. (orig.)
High Energy Particle Accelerators
Audio Productions, Inc, New York
1960-01-01
Film about the different particle accelerators in the US. Nuclear research in the US has developed into a broad and well-balanced program.Tour of accelerator installations, accelerator development work now in progress and a number of typical experiments with high energy particles. Brookhaven, Cosmotron. Univ. Calif. Berkeley, Bevatron. Anti-proton experiment. Negative k meson experiment. Bubble chambers. A section on an electron accelerator. Projection of new accelerators. Princeton/Penn. build proton synchrotron. Argonne National Lab. Brookhaven, PS construction. Cambridge Electron Accelerator; Harvard/MIT. SLAC studying a linear accelerator. Other research at Madison, Wisconsin, Fixed Field Alternate Gradient Focusing. (FFAG) Oakridge, Tenn., cyclotron. Two-beam machine. Comments : Interesting overview of high energy particle accelerators installations in the US in these early years. .
Abstract composition rule for relativistic kinetic energy in the thermodynamical limit
Biro, T S
2008-01-01
We demonstrate by simple mathematical considerations that a power-law tailed distribution in the kinetic energy of relativistic particles can be a limiting distribution seen in relativistic heavy ion experiments. We prove that the infinite repetition of an arbitrary composition rule on an infinitesimal amount leads to a rule with a formal logarithm. As a consequence the stationary distribution of energy in the thermodynamical limit follows the composed function of the Boltzmann-Gibbs exponential with this formal logarithm. In particular, interactions described as solely functions of the relative four-momentum squared lead to kinetic energy distributions of the Tsallis-Pareto (cut power-law) form in the high energy limit.
On relativistic motion of a pair of particles having opposite signs of masses
Ivanov, Pavel B.
2012-12-01
In this methodological note, we consider, in a weak-fleld limit, the relativistic linear motion of two particles with masses of opposite signs and a small difference between their absolute values: m_{1,2}=+/- (\\mu+/- \\Delta \\mu) , \\mu \\gt 0, \\vert\\Delta \\mu \\vert \\ll\\mu. In 1957, H Bondi showed in the framework of both Newtonian analysis and General Relativity that, when the relative motion of particles is absent, such a pair can be accelerated indefinitely. We generalize the results of his paper to account for the small nonzero difference between the velocities of the particles. Assuming that the weak-field limit holds and the dynamical system is conservative, an elementary treatment of the problem based on the laws of energy and momentum conservation shows that the system can be accelerated indefinitely, or attain very large asymptotic values of the Lorentz factor \\gamma. The system experiences indefinite acceleration when its energy-momentum vector is null and the mass difference \\Delta \\mu \\le 0. When the modulus of the square of the norm of the energy-momentum vector, \\vert N^{\\,2}\\vert, is sufficiently small, the system can be accelerated to very large \\gamma \\propto \\vert N^{\\,2}\\vert^{-1}. It is stressed that, when only leading terms in the ratio of a characteristic gravitational radius to the distance between the particles are retained, our elementary analysis leads to equations of motion equivalent to those derived from relativistic weak-field equations of motion by Havas and Goldberg in 1962. Thus, in the weak-field approximation it is possible to bring the system to the state with extremely high values of \\gamma. The positive energy carried by the particle with positive mass may be conveyed to other physical bodies, say by intercepting this particle with a target. If we suppose that there is a process of production of such pairs and the particles with positive mass are intercepted, while the negative mass particles are expelled
Ratchet effect on a relativistic particle driven by external forces
Quintero, Niurka R [Departamento de Fisica Aplicada I, Escuela Universitaria Politecnica, Universidad de Sevilla, Calle Virgen de Africa 7, E-41011 Sevilla (Spain); Alvarez-Nodarse, Renato [Departamento de Analisis Matematico, Facultad de Matematicas, Universidad de Sevilla, Apdo 1160, E-41080 Sevilla (Spain); Cuesta, Jose A, E-mail: niurka@us.es, E-mail: ran@us.es, E-mail: cuesta@math.uc3m.es [Grupo Interdisciplinar de Sistemas Complejos (GISC), Departamento de Matematicas, Universidad Carlos III de Madrid, Avenida de la Universidad 30, E-28911 Leganes, Madrid (Spain)
2011-10-21
We study the ratchet effect of a damped relativistic particle driven by both asymmetric temporal bi-harmonic and time-periodic piecewise constant forces. This system can be formally solved for any external force, providing the ratchet velocity as a nonlinear functional of the driving force. This allows us to explicitly illustrate the functional Taylor expansion formalism recently proposed for this kind of systems. The Taylor expansion reveals particularly useful to obtain the shape of the current when the force is periodic, piecewise constant. We also illustrate the somewhat counterintuitive effect that introducing damping may induce a ratchet effect. When the force is symmetric under time-reversal and the system is undamped, under symmetry principles no ratchet effect is possible. In this situation increasing damping generates a ratchet current which, upon increasing the damping coefficient eventually reaches a maximum and decreases toward zero. We argue that this effect is not specific of this example and should appear in any ratchet system with tunable damping driven by a time-reversible external force. (paper)
Relativistic particles with rigidity and torsion in D = 3 spacetimes
Barros, Manuel [Departamento de GeometrIa y TopologIa, Universidad de Granada, 18071 Granada (Spain); Ferrandez, Angel [Departamento de Matematicas, Universidad de Murcia, Campus de Espinardo, 30100 Espinardo Murcia (Spain); Javaloyes, Miguel Angel [Departamento de Matematica, Instituto de Matematica e EstatIstica, Universidade de Sao Paulo, Rua do Matao 1010, CEP 05508-900, Sao Paulo, SP (Brazil); Lucas, Pascual [Departamento de Matematicas, Universidad de Murcia, Campus de Espinardo, 30100 Espinardo Murcia (Spain)
2005-02-07
Models describing relativistic particles, where Lagrangian densities depend linearly on both the curvature and the torsion of the trajectories, are revisited in D = 3 Lorentzian spacetimes with constant curvature. The moduli spaces of trajectories are completely and explicitly determined. Trajectories are Lancret curves including ordinary helices. To get the geometric integration of the solutions, we design algorithms that essentially involve the Lancret program as well as the notions of scrolls and Hopf tubes. The most interesting and consistent models appear in anti-de Sitter spaces, where the Hopf mappings, both the standard and the Lorentzian ones, play an important role. The moduli subspaces of closed solitons in anti-de Sitter settings are also obtained. Our main tool is the isoperimetric inequality in the hyperbolic plane. The mass spectra of these models are also obtained. The main characteristic of the anti-de Sitter space comes from the presence of real gravity, which becomes essential to find some system with only massive states. This fact, on one hand, has no equivalent in flat spaces, where spectra necessarily present tachyonic sectors and, on the other hand, solves an early stated problem.
Baryshevsky, V.G. (Inst. of Nuclear Problems, Minsk (Belarus)); Dubovskaya, I.Ya. (Lawrence Berkeley Lab., CA (United States))
1991-12-01
This report discusses: the dispersion characteristics of parametric x-ray radiation (PXR) and diffraction radiation of oscillator; cooperative effects in x-radiation by charged particles in crystals; and diffraction x-radiation by relativistic oscillator.
Radiation of non-relativistic particle on a conducting sphere and a string of spheres
Shul'ga, N F; Larikova, E A
2016-01-01
The radiation arising under uniform motion of non-relativistic charged particle by (or through) perfectly conducting sphere is considered. The rigorous results are obtained using the method of images known from electrostatics.
Relativistic calculation of the triton binding energy and its implications
Stadler, A; Stadler, Alfred; Gross, Franz
1996-01-01
First results for the triton binding energy obtained from the relativistic spectator or Gross equation are reported. The Dirac structure of the nucleons is taken into account. Numerical results are presented for a family of realistic OBE models with off-shell scalar couplings. It is shown that these off-shell couplings improve both the fits to the two-body data and the predictions for the binding energy.
Proton induced fission of 181-Ta at relativistic energies
Ayyad, Y; Casarejos, E; Álvarez-Pol, H; Bacquias, A; Boudard, A; Caamaño, M; Enqvist, T; Föhr, V; Kelić-Heil, A; Kezzar, K; Leray, S; Paradela, C; Pérez-Loureiro, D; Pleskač, R; Tarrío, D
2012-01-01
Total fission cross sections of 181-Ta induced by protons at different relativistic energies have been measured at GSI, Darmstadt. The inverse kinematics technique used together with a dedicated set-up, made it possible to determine these cross sections with high accuracy. The new data obtained in this experiment will contribute to the understanding of the fission process at high excitation energies. The results are compared with data from previous experiments and systematics for proton-induced fission cross sections.
Evidence for acceleration of outer zone electrons to relativistic energies by whistler mode chorus
N. P. Meredith
Full Text Available We use plasma wave and electron data from the Combined Release and Radiation Effects Satellite (CRRES to investigate the viability of a local stochastic electron acceleration mechanism to relativistic energies driven by gyroresonant interactions with whistler mode chorus. In particular, we examine the temporal evolution of the spectral response of the electrons and the waves during the 9 October 1990 geomagnetic storm. The observed hardening of the electron energy spectra over about 3 days in the recovery phase is coincident with prolonged substorm activity, as monitored by the AE index and enhanced levels of whistler mode chorus waves. The observed spectral hardening is observed to take place over a range of energies appropriate to the resonant energies associated with Doppler-shifted cyclotron resonance, as supported by the construction of realistic resonance curves and resonant diffusion surfaces. Furthermore, we show that the observed spectral hardening is not consistent with energy-independent radial diffusion models. These results provide strong circumstantial evidence for a local stochastic acceleration mechanism, involving the energisation of a seed population of electrons with energies of the order of a few hundred keV to relativistic energies, driven by wave-particle interactions involving whistler mode chorus. The results suggest that this mechanism contributes to the reformation of the relativistic outer zone population during geomagnetic storms, and is most effective when the recovery phase is characterised by prolonged substorm activity. An additional significant result of this paper is that we demonstrate that the lower energy part of the storm-time electron distribution is in steady-state balance, in accordance with the Kennel and Petschek (1966 theory of limited stably-trapped particle fluxes.
Key words. Magnetospheric physics (storms and substorms, energetic particles, trapped – Space plasma physics (wave-particle
Development of a relativistic Particle In Cell code PARTDYN for linear accelerator beam transport
Phadte, D.; Patidar, C. B.; Pal, M. K.
2017-04-01
A relativistic Particle In Cell (PIC) code PARTDYN is developed for the beam dynamics simulation of z-continuous and bunched beams. The code is implemented in MATLAB using its MEX functionality which allows both ease of development as well higher performance similar to a compiled language like C. The beam dynamics calculations carried out by the code are compared with analytical results and with other well developed codes like PARMELA and BEAMPATH. The effect of finite number of simulation particles on the emittance growth of intense beams has been studied. Corrections to the RF cavity field expressions were incorporated in the code so that the fields could be calculated correctly. The deviations of the beam dynamics results between PARTDYN and BEAMPATH for a cavity driven in zero-mode have been discussed. The beam dynamics studies of the Low Energy Beam Transport (LEBT) using PARTDYN have been presented.
Constraints on particle acceleration sites in the Crab Nebula from relativistic MHD simulations
Olmi, Barbara; Amato, Elena; Bucciantini, Niccolò
2015-01-01
The Crab Nebula is one of the most efficient accelerators in the Galaxy and the only galactic source showing direct evidence of PeV particles. In spite of this, the physical process behind such effective acceleration is still a deep mystery. While particle acceleration, at least at the highest energies, is commonly thought to occur at the pulsar wind termination shock, the properties of the upstream flow are thought to be non-uniform along the shock surface, and important constraints on the mechanism at work come from exact knowledge of where along this surface particles are being accelerated. Here we use axisymmetric relativistic MHD simulations to obtain constraints on the acceleration site(s) of particles of different energies in the Crab Nebula. Various scenarios are considered for the injection of particles responsible for synchrotron radiation in the different frequency bands, radio, optical and X-rays. The resulting emission properties are compared with available data on the multi wavelength time varia...
Magnetic Field Generation, Particle Energization and Radiation at Relativistic Shear Boundary Layers
Liang, Edison; Fu, Wen; Spisak, Jake; Boettcher, Markus
2015-11-01
Recent large scale Particle-in-Cell (PIC) simulations have demonstrated that in unmagnetized relativistic shear flows, strong transverse d.c. magnetic fields are generated and sustained by ion-dominated currents on the opposite sides of the shear interface. Instead of dissipating the shear flow free energy via turbulence formation and mixing as it is usually found in MHD simulations, the kinetic results show that the relativistic boundary layer stabilizes itself via the formation of a robust vacuum gap supported by a strong magnetic field, which effectively separates the opposing shear flows, as in a maglev train. Our new PIC simulations have extended the runs to many tens of light crossing times of the simulation box. Both the vacuum gap and supporting magnetic field remain intact. The electrons are energized to reach energy equipartition with the ions, with 10% of the total energy in electromagnetic fields. The dominant radiation mechanism is similar to that of a wiggler, due to oscillating electron orbits around the boundary layer.
Harder, T Mark
2016-01-01
It is shown how Fermionic material particles can emerge from a covariant formulation of the de Broglie-Bohm theory. Material particles are continuous fields, formed as the eigenvalue of the Schrodinger field operator, evaluated along a Bohmian trajectory. The motivation for this work is due to a theorem proved by Malament that states there cannot be a relativistic quantum mechanics of localizable particles.
A search for relativistic particles with fractional electric charge at the Cern collider
Banner, M.; Kofoed-Hansen, O.
1983-01-01
A search for relativistic particles with fractional electric charge has been performed at the CERN collider using a telescope of scintillation counters to detect particles with abnormally low ionisation. The thickness of the detector (40 gr cm−2) limits this search to particles without strong...
Energy loss and longitudinal wakefield of relativistic short proton bunches in electron clouds
O. Boine-Frankenheim
2012-05-01
Full Text Available The aim of our study is the numerical computation of the wakefield and energy loss per unit length for relativistic, short (<10 ns proton bunches interacting with an electron cloud inside the beam pipe. We present analytical expressions for the energy loss in the impulse kick approximation. For the simulation of the wakefields a 2D self-consistent, electrostatic particle-in-cell (PIC code is employed. Results for the energy loss and for the wakefields are presented for the parameter scope of the CERN LHC and SPS. For selected parameters the results are compared to a three-dimensional (3D electromagnetic PIC code.
Relativistic, model-independent, three-particle quantization condition
Hansen, Maxwell T
2013-01-01
This is a combined write-up for two talks which were given consecutively and which described different aspects of the same topic. We present a generalization of L\\"uscher's relation between the finite-volume spectrum and S-matrix to three particles. Specifically, we consider a scalar field theory, which has a $\\mathbb{Z}_2$ symmetry that prevents even/odd coupling. The theory is assumed to have no two-particle bound states and to have two-particle phase shifts that are bounded by $\\pi/2$ in the regime of elastic scattering. Considering center of mass energies between one and five particle masses, we evaluate a three-to-three finite-volume correlator to all orders in perturbation theory. Only terms which are exponentially suppressed in volume are neglected. From poles in the correlator we then determine the relation between finite-volume spectrum and scattering quantities. In this analysis one must carefully treat the unitary cusp at two-particle threshold. This point, which was neglected in the conference tal...
Nagle, J L
2003-01-01
The Relativistic Heavy Ion Collider (RHIC) came online in 2000, and the last three years have provided a wealth of new experimental data and theoretical work in this new energy frontier for nuclear physics. The transition from quarks and gluons bound into hadrons to a deconfined quark-gluon plasma is expected to occur at these energies, and the effort to understand the time evolution of these complex systems has been significantly advanced. The heavy ion parallel session talks from the Conference on the Intersections of Particle and Nuclear Physics (CIPANP) 2003 are posted at: http://www.phenix.bnl.gov/WWW/publish/nagle/CIPANP/. We provide a brief summary of these sessions here.
A. Chandrasekhar Reddy; Jatin Rathod; Girija Rajaram; Radharani Alyana; D. S. Misra; C. G. Patil; M. Y. S. Prasad; A. G. Ananth
2008-03-01
In view of the renewed interest in the study of energetic particles in the outer radiation belt of the earth, we feel it will be helpful in looking for the energy dependence of the electron energy spectrum at geostationary orbit. This may give us some insight into how we can safeguard geostationary satellites from functional anomalies of the deep dielectric charging type, which are caused by charge accumulation and subsequent discharge of relativistic electrons. In this study we examine whether there is any energy dependence in relativistic electron enhancements at geosynchronous altitudes during solar energetic proton events of 2005.
Relativistic Calculations and Measurements of Energies, Auger Rates, and Lifetimes.
1982-12-01
Research and Industry, Denton, Texas, 8-10 November 1982. 7. B. Crasemann: "Efectos Relativ’sticos y de QED Sobre las Transiciones Rayos - X y Auger Entre...INNER-SHELL IONIZATION BY PROTONS X -RAY EMISSION BREIT INTERACTION AUGER TRANSITIONS DIRAC-HARTREE-SLATER COMPUTATIONS SYNCHROTRON RADIATION RESONANT...computations, including relativistic and quantum- electrodynamic effects, of atomic energy levels and of x -ray and Auger transitions in atoms with one or
Loveland, W.D.
1991-08-01
The work described herein is part of a project involving the study of low energy (< 10 MeV/A), intermediate energy (10--100 MeV/A) and relativistic (> 250 MeV/A) heavy ion reactions. In the low energy regime, we published a monograph on the properties of the heaviest elements and used that publication as a basis for making a set of best'' semi-empirical predictions of heavy element decay properties. The intermediate energy research effort focussed upon the completion of studies already begun and the initiation of a number of new experiments. In our study of a interaction of 21 MeV/nucleon {sup 129}Xe with {sup 197}Au, we compared the characteristics of the observed deep inelastic phenomena with various models of dissipative reactions and found significant discrepancies between observations and predictions. These discrepancies seemed to be caused by an improper treatment of pre-equilibrium in the early stages of the collision. In our study of the relativistic interaction of 400 MeV/nucleon {sup 12}C with {sup 197}Au, we reported the first direct physical measurement of the properties of the spallation residues from a nucleus-nucleus collision. We found the residue energies to be much lower than those predicted by the intranuclear cascade model, indicating some substantial modifications of that model are needed. But, we also found, indications of significant, non-zero values of the residue transverse momentum, a finding that calls into question the interpretation of a number of radiochemical recoil studies of the kinematics of high energy reactions. A program of performing numerical simulations of intermediate and high energy nuclear collisions using the QMD model was initiated.
Fan, Peifeng; Liu, Jian; Xiang, Nong; Yu, Zhi
2016-01-01
A manifestly covariant, or geometric, field theory for relativistic classical particle-field system is developed. The connection between space-time symmetry and energy-momentum conservation laws for the system is established geometrically without splitting the space and time coordinates, i.e., space-time is treated as one identity without choosing a coordinate system. To achieve this goal, we need to overcome two difficulties. The first difficulty arises from the fact that particles and field reside on different manifold. As a result, the geometric Lagrangian density of the system is a function of the 4-potential of electromagnetic fields and also a functional of particles' world-lines. The other difficulty associated with the geometric setting is due to the mass-shell condition. The standard Euler-Lagrange (EL) equation for a particle is generalized into the geometric EL equation when the mass-shell condition is imposed. For the particle-field system, the geometric EL equation is further generalized into a w...
Pion tensor force and nuclear binding energy in the relativistic Hartree-Fock formalism
Marcos, S.; López-Quelle, M.; Niembro, R.; Savushkin, L. N.
2014-03-01
The binding energies of several isotopic families are studied within the relativistic Hartree-Fock approximation with the pseudovector coupling for the πN vertex, to find out a suitable strength for the effective pion tensor force (EPTF). An approximation for determining separately the contributions of the central and tensor forces generated by pion is considered. The results for heavy nuclei indicate that a realistic strength for the EPTF is smaller than a half of that appearing in the OPEP. This conclusion also applies to the results for the single-particle energies. Besides, it has been found that there is a genuine relativistic contribution of the EPTF in nuclear matter which is small but significant.
Mitigating Particle Integration Error in Relativistic Laser-Plasma Simulations
Higuera, Adam; Weichmann, Kathleen; Cowan, Benjamin; Cary, John
2016-10-01
In particle-in-cell simulations of laser wakefield accelerators with a0 greater than unity, errors in particle trajectories produce incorrect beam charges and energies, predicting performance not realized in experiments such as the Texas Petawatt Laser. In order to avoid these errors, the simulation time step must resolve a time scale smaller than the laser period by a factor of a0. If the Yee scheme advances the fields with this time step, the laser wavelength must be over-resolved by a factor of a0 to avoid dispersion errors. Here is presented and demonstrated with Vorpal simulations, a new electromagnetic algorithm, building on previous work, correcting Yee dispersion for arbitrary sub-CFL time steps, reducing simulation times by a0.
Exact two-component relativistic energy band theory and application
Zhao, Rundong; Zhang, Yong; Xiao, Yunlong; Liu, Wenjian, E-mail: liuwj@pku.edu.cn [Beijing National Laboratory for Molecular Sciences, Institute of Theoretical and Computational Chemistry, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, and Center for Computational Science and Engineering, Peking University, Beijing 100871 (China)
2016-01-28
An exact two-component (X2C) relativistic density functional theory in terms of atom-centered basis functions is proposed for relativistic calculations of band structures and structural properties of periodic systems containing heavy elements. Due to finite radial extensions of the local basis functions, the periodic calculation is very much the same as a molecular calculation, except only for an Ewald summation for the Coulomb potential of fluctuating periodic monopoles. For comparison, the nonrelativistic and spin-free X2C counterparts are also implemented in parallel. As a first and pilot application, the band gaps, lattice constants, cohesive energies, and bulk moduli of AgX (X = Cl, Br, I) are calculated to compare with other theoretical results.
Exact two-component relativistic energy band theory and application.
Zhao, Rundong; Zhang, Yong; Xiao, Yunlong; Liu, Wenjian
2016-01-28
An exact two-component (X2C) relativistic density functional theory in terms of atom-centered basis functions is proposed for relativistic calculations of band structures and structural properties of periodic systems containing heavy elements. Due to finite radial extensions of the local basis functions, the periodic calculation is very much the same as a molecular calculation, except only for an Ewald summation for the Coulomb potential of fluctuating periodic monopoles. For comparison, the nonrelativistic and spin-free X2C counterparts are also implemented in parallel. As a first and pilot application, the band gaps, lattice constants, cohesive energies, and bulk moduli of AgX (X = Cl, Br, I) are calculated to compare with other theoretical results.
Pacholczyk, A. G.; Stepinski, T. F.
1988-01-01
An accreting cluster of black holes in an active galactic nucleus is a natural site for a system of shock structures with a hierarchy of sizes, corresponding to the distribution of masses in the cluster. Accreted gas containing some magnetic fields and supersonically falling onto the core forms shocks on the outside of each hole and these shocks are capable of accelerating relativistic particles. The energies reached in a single shock are size rather than acceleration time limited and are proportional to the mass of the hole with a proportionality constant being a function of the position of the hole within a cluster and the model of the cluster and the shock formation. These energies are adequate to explain the observed properties of synchrotron and inverse-Compton radiation from these objects. The resulting energy spectrum of particles in the cluster in 'zeroth' approximation has the form of a doubly broken power law with indices of two and three on both extremes of the energy domain respectively, bridged by an index of about 2.5.
Pacholczyk, A.G.; Stepinski, T.F.
1988-01-01
An accreting cluster of black holes in an active galactic nucleus is a natural site for a system of shock structures with a hierarchy of sizes, corresponding to the distribution of masses in the cluster. Accreted gas containing some magnetic fields and supersonically falling onto the core forms shocks on the outside of each hole and these shocks are capable of accelerating relativistic particles. The energies reached in a single shock are size rather than acceleration time limited and are proportional to the mass of the hole with a proportionality constant being a function of the position of the hole within a cluster and the model of the cluster and the shock formation. These energies are adequate to explain the observed properties of synchrotron and inverse-Compton radiation from these objects. The resulting energy spectrum of particles in the cluster in zeroth approximation has the form of a doubly broken power law with indices of two and three on both extremes of the energy domain respectively, bridged by an index of about 2.5. 16 references.
Oliveira, Diego F.M., E-mail: diegofregolente@gmail.com [Institute for Multiscale Simulations, Friedrich-Alexander Universität, D-91052, Erlangen (Germany); Leonel, Edson D., E-mail: edleonel@rc.unesp.br [Departamento de Estatística, Matemática Aplicada e Computação, UNESP, Univ. Estadual Paulista, Av. 24A, 1515, Bela Vista, 13506-900, Rio Claro, SP (Brazil); Departamento de Física, UNESP, Univ. Estadual Paulista, Av. 24A, 1515, 13506-900, Rio Claro, SP (Brazil)
2012-11-01
We study some dynamical properties for the problem of a charged particle in an electric field considering both the low velocity and relativistic cases. The dynamics for both approaches is described in terms of a two-dimensional and nonlinear mapping. The structure of the phase spaces is mixed and we introduce a hole in the chaotic sea to let the particles to escape. By changing the size of the hole we show that the survival probability decays exponentially for both cases. Additionally, we show for the relativistic dynamics, that the introduction of dissipation changes the mixed phase space and attractors appear. We study the parameter space by using the Lyapunov exponent and the average energy over the orbit and show that the system has a very rich structure with infinite family of self-similar shrimp shaped embedded in a chaotic region.
The Earth's Electron Radiation Belts Modeling: from the Source Population to Relativistic Energies
Aseev, N.; Shprits, Y. Y.; Kellerman, A. C.; Drozdov, A.; Zhu, H.
2016-12-01
The dynamics of the Earth's electron radiation belts is characterized by intricate interactions of different particle populations. During the main phase of a geomagnetic storm, electron source (tens keV) and seed (hundreds keV) populations are injected from the plasma sheet to the outer belt region. The source population transfers energy to electromagnetic waves, while the seed population can be accelerated locally by interaction with chorus waves. Electrons can also be lost by scattering into the loss cone due to wave-particle interaction and by magnetopause shadowing due to outward radial motion. In this work, we present results of simulations of the dynamics of electron fluxes in the inner magnetosphere from a few keV to relativistic energies of several MeV using the VERB-4D code. The code includes radial, energy and pitch angle diffusion, convection and adiabatic effects due to compression or expansion of the magnetic field. We extended the spatial outer boundary of the computational domain to 10-15 RE which allow us to study, how the source and seed population particles are convected from the plasma sheet, accelerated to relativistic energies and lost to the atmosphere or the magnetopause. The results of simulations reproduce Van Allen Probes, GOES and THEMIS observations, indicating that magnetospheric convection is the main driver of electron dynamics above the GEO, while radial diffusion and local diffusion are the most important processes in the outer belt region.
On the maximum energy of shock-accelerated cosmic rays at ultra-relativistic shocks
Reville, B
2014-01-01
The maximum energy to which cosmic rays can be accelerated at weakly-magnetised ultra-relativistic shocks is investigated. We demonstrate that for such shocks, in which the scattering of energetic particles is mediated exclusively by ion skin-depth scale structures, as might be expected for a Weibel-mediated shock, there is an intrinsic limit on the maximum energy to which particles can be accelerated. This maximum energy is determined from the requirement that particles must be isotropised in the downstream plasma frame before the mean field transports them far downstream, and falls considerably short of what is required to produce ultra-high energy cosmic rays. To circumvent this limit, a highly disorganised field is required on larger scales. The growth of cosmic-ray induced instabilities on wavelengths much longer than the ion-plasma skin depth, both upstream and downstream of the shock, is considered. While these instabilities may play an important role in magnetic field amplification at relativistic sho...
Fanizza, G.; Marozzi, G.; Veneziano, G.
2016-01-01
Including the metric fluctuations of a realistic cosmological geometry we reconsider an earlier suggestion that measuring the relative time-of-flight of ultra-relativistic particles can provide interesting constraints on fundamental cosmological and/or particle parameters. Using convenient properties of the geodetic light-cone gauge we first compute, to leading order in the Lorentz factor and for a generic (inhomogeneous, anisotropic) space-time, the relative arrival times of two ultra-relativistic particles as a function of their masses and energies as well as of the details of the large-scale geometry. Remarkably, the result can be written as an integral over the unperturbed line-of-sight of a simple function of the local, inhomogeneous redshift. We then evaluate the irreducible scatter of the expected data-points due to first-order metric perturbations, and discuss, for an ideal source of ultra-relativistic particles, the resulting attainable precision on the determination of different physical parameters.
Fanizza, G., E-mail: Giuseppe.Fanizza@ba.infn.it [Dipartimento di Fisica, Università di Bari, Via G. Amendola 173, 70126 Bari (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Bari, Bari (Italy); Université de Genève, Département de Physique Théorique and CAP, 24 quai Ernest-Ansermet, CH-1211 Genève 4 (Switzerland); Gasperini, M., E-mail: maurizio.gasperini@ba.infn.it [Dipartimento di Fisica, Università di Bari, Via G. Amendola 173, 70126 Bari (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Bari, Bari (Italy); Marozzi, G., E-mail: giovanni.marozzi@gmail.com [Université de Genève, Département de Physique Théorique and CAP, 24 quai Ernest-Ansermet, CH-1211 Genève 4 (Switzerland); Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud 150, Urca, CEP 22290-180, Rio de Janeiro (Brazil); Veneziano, G., E-mail: Gabriele.Veneziano@cern.ch [Collège de France, 11 Place M. Berthelot, 75005 Paris (France); CERN, Theory Unit, Physics Department, CH-1211 Geneva 23 (Switzerland); Dipartimento di Fisica, Università di Roma La Sapienza, Rome (Italy)
2016-06-10
Including the metric fluctuations of a realistic cosmological geometry we reconsider an earlier suggestion that measuring the relative time-of-flight of ultra-relativistic particles can provide interesting constraints on fundamental cosmological and/or particle parameters. Using convenient properties of the geodetic light-cone coordinates we first compute, to leading order in the Lorentz factor and for a generic (inhomogeneous, anisotropic) space–time, the relative arrival times of two ultra-relativistic particles as a function of their masses and energies as well as of the details of the large-scale geometry. Remarkably, the result can be written as an integral over the unperturbed line-of-sight of a simple function of the local, inhomogeneous redshift. We then evaluate the irreducible scatter of the expected data-points due to first-order metric perturbations, and discuss, for an ideal source of ultra-relativistic particles, the resulting attainable precision on the determination of different physical parameters.
Are non-relativistic neutrinos the dark matter particles?
Nieuwenhuizen, Theo M.
2010-06-01
The dark matter of a spherical, relaxed galaxy cluster is modeled by isothermal, non-interacting fermions; the galaxies and X-ray gas by isothermal classical distributions. A fit to lensing data of the cluster Abell 1689 works well and yields a mass of a few eV. This low value casts doubt on the existence of a Cold Dark Matter particle. The best case is the neutrino, for which in the cluster all 12 left- and righthanded modes are available. The fit gives an average mass 1.45(h/0.70)1/2 eV, with 2% error, while neutrino oscillations bring deviations of order meV. A neutrino mass between 0.2 and 2 eV will be searched in the Katrin experiment in 2012. The ideal value is mν = Yeme = 1.4998 eV, where Ye = 23/4GF1/2me is the Yukawa coupling of the electron. It occurs for reduced Hubble constant h = 0.744 with 4% error, right on top of and slightly sharper than the presently best supernova value of Riess et al. 2009, h = 0.742 with 4.8% error. In the cluster the neutrinos have a temperature of 0.045 K and a de Broglie length of 0.20 mm. They establish a quantum structure of several million light years across, the largest known in the Universe. The virial α-particle temperature of 9.9+/-1.1 keV/kB coincides with the average one of X-rays, while also the gas profile comes out well. Active neutrinos alone with the 1.45 eV mass give some 9.5% dark matter, more than allowed by the cold dark matter papradigm. A dark matter fraction of some 19%, Ων = (h/0.70)-3/20.189 (4), occurs for 12 degrees of freedom, i. e., for 3 families of left plus right handed neutrinos. The sterile modes may be produced in the early universe if there is a small Majorana mass matrix of order meV, on top of the Dirac matrix with ~1.45 eV masses. The neutrinos are free-streaming in the early universe and play no role during the decoupling. But now they are not homogeneous anymore. They condense on the Abell 1689 cluster fairly late, at redshift z~6-8, a prediction testable in future observations
Polko, Peter; Markoff, Sera
2012-01-01
We present a new, approximate method for modelling the acceleration and collimation of relativistic jets in the presence of gravity. This method is self-similar throughout the computational domain where gravitational effects are negligible and, where significant, self-similar within a flux tube. These solutions are applicable to jets launched from a small region (e.g., near the inner edge of an accretion disk). As implied by earlier work, the flow can converge onto the rotation axis, potentially creating a collimation shock. In this first version of the method, we derive the gravitational contribution to the relativistic equations by analogy with non-relativistic flow. This approach captures the relativistic kinetic gravitational mass of the flowing plasma, but not that due to internal thermal and magnetic energies. A more sophisticated treatment, derived from the basic general relativistic magnetohydrodynamical equations, is currently being developed. Here we present an initial exploration of parameter space...
Thermodynamics of relativistic quantum fields: extracting energy from gravitational waves
Bruschi, David Edward
2016-01-01
We investigate the quantum thermodynamical properties of localised relativistic quantum fields that can be used as quantum thermal machines. We study the efficiency and power of energy transfer between the classical degrees of freedom, such as the energy input due to motion or to an impinging gravitational wave, and the excitations of the confined quantum field. We find that the efficiency of energy transfer depends dramatically on the input initial state of the system. Furthermore, we investigate the ability to extract the energy and to store it in a battery. This process is inefficient in optical cavities but is significantly enhanced when employing trapped Bose Einstein Condensates. Finally, we apply our techniques to a setup where an impinging gravitational wave excites the phononic modes of a Bose Einstein Condensate. We find that, in this case, the amount of energy transfer to the phonons increases with time and quickly approaches unity. These results suggest that, in the future, it might be possible to...
Cardoso, V; Cardoso, Vitor; Lemos, Jos\\'e P. S.
2003-01-01
In this paper, we consider the gravitational radiation generated by the collision of highly relativistic particles with rotating Kerr black holes. We use the Sasaki-Nakamura formalism to compute the waveform, energy spectra and total energy radiated during this process. We show that the gravitational spectrum for high-energy collisions has definite characteristic universal features, which are independent of the spin of the colliding objects. We also discuss possible connections between these results and the black hole-black hole collision at the speed of light process. With these results at hand, we predict that during the high speed collision of a non-rotating hole with a rotating one, about 35% of the total energy gets converted into gravitational waves. Thus, if one is able to produce black holes at the Large Hadron Collider, 35% of the partons' energy should be emitted during the so called balding phase. This energy will be missing, since we don't have gravitational wave detectors able to measure such amp...
Li, En-Kun; Geng, Jin-Ling
2014-01-01
The modified holographic Ricci dark energy coupled to interacting relativistic and non-relativistic dark matter is considered in the nonflat Friedmann-Robertson-Walker universe. Through examining the deceleration parameter, one can find that the transition time of the Universe from decelerating to accelerating phase in the interacting holographic Ricci dark energy model is close to that in the $\\Lambda$ cold dark matter model. The evolution of modified holographic Ricci dark energy's state parameter and the evolution of dark matter and dark energy's densities shows that the dark energy holds the dominant position from the near past to the future. By studying the statefinder diagnostic and the evolution of the total pressure, one can find that this model could explain the Universe's transition from the radiation to accelerating expansion stage through the dust stage. According to the $Om$ diagnostic, it is easy to find that when the interaction is weak and the proportion of relativistic dark matter in total da...
The Work and the Energy in Special Theory of Relativistic Dynamics%相对论中的功和能
籍延坤; 郭红
2001-01-01
以经典力学某些量为线索,根据经典动力学的基本方程,采用物理上常用的类比的方法建立了狭义相对论动力学的基本方程,由该基本方程对空间的累积效应,可以引入相对论动力学中质点和质点系的质量、运动质量、动量、动能、静能、机械能、相对论能量和力以及力的功的基本概念。得到了相对论动力学中的功和能关系式即质点和质点系的动能定理、质点系的功能原理、机械能守恒定律与能量守恒定律以及能量准守恒定律。%Some quantities in classical mechanics being taken as clue, a fundamental equation of special theory of relativistic dynamics has been established based on the fundamental equation of classical mechanics and by using analogy method . From the accumulative effect of this equation to space, the basic concepts of rest mass, moving mass, momentum, kinetic energy, rest energy, mechanical energy, relativistic energy , force, and the work of force of particle or particle system in special theory of relativistic dynamics can be introduced. The relation formula between work and energy in special theory of relativistic dynamics, i.e. kinetic energy theorem of particle or particle system, the principle of work and energy, the conservation law of mechanical energy and quasi-conservation law of energy in particle system have been obtained as well.
A Non-Perturbative, Finite Particle Number Approach to Relativistic Scattering Theory
Lindesay, James V
2001-05-11
We present integral equations for the scattering amplitudes of three scalar particles, using the Faddeev channel decomposition, which can be readily extended to any finite number of particles of any helicity. The solution of these equations, which have been demonstrated to be calculable, provide a non-perturbative way of obtaining relativistic scattering amplitudes for any finite number of particles that are Lorentz invariant, unitary, cluster decomposable and reduce unambiguously in the non-relativistic limit to the non-relativistic Faddeev equations. The aim of this program is to develop equations which explicitly depend upon physically observable input variables, and do not require ''renormalization'' or ''dressing'' of these parameters to connect them to the boundary states.
Rocca, J.; Bargsten, C.; Hollinger, R.; Shylaptsev, V.; Wang, S.; Rockwood, A.; Wang, Y.; Keiss, D.; Capeluto, M.; Kaymak, V.; Pukhov, A.; Tommasini, R.; London, R.; Park, J.
2016-10-01
Ultra-high-energy-density (UHED) plasmas, characterized by energy densities >1 x 108 J cm-3 and pressures greater than a gigabar are encountered in the center of stars and in inertial confinement fusion capsules driven by the world's largest lasers. Similar conditions can be obtained with compact, ultra-high contrast, femtosecond lasers focused to relativistic intensities onto aligned nanowire array targets. Here we report the measurement of the key physical process in determining the energy density deposited in high aspect ratio nanowire array plasmas: the energy penetration. By monitoring the x-ray emission from buried Co tracer segments in Ni nanowire arrays irradiated at an intensity of 4 x 1019 W cm-2, we demonstrate energy penetration depths of several μm, leading to UHED plasmas of that size. Relativistic 3D particle-in-cell-simulations validated by these measurements predict that irradiation of nanostructures at increased intensity will lead to a virtually unexplored extreme UHED plasma regime characterized by energy densities in excess of 8 x 1010 J cm-3, equivalent to a pressure of 0.35 Tbar. This work was supported by the Fusion Energy Program, Office of Science of the U.S Department of Energy, and by the Defense Threat Reduction Agency.
Parton-Hadron-String Dynamics at Relativistic Collider Energies
Bratkovskaya, E L; Konchakovski, V P; Linnyk, O
2011-01-01
The novel Parton-Hadron-String Dynamics (PHSD) transport approach is applied to nucleus-nucleus collisions at RHIC energies with respect to differential hadronic spectra in comparison to available data. The PHSD approach is based on a dynamical quasiparticle model for partons (DQPM) matched to reproduce recent lattice-QCD results from the Wuppertal-Budapest group in thermodynamic equilibrium. The transition from partonic to hadronic degrees of freedom is described by covariant transition rates for the fusion of quark-antiquark pairs or three quarks (antiquarks), respectively, obeying flavor current-conservation, color neutrality as well as energy-momentum conservation. Our dynamical studies for heavy-ion collisions at relativistic collider energies are compared to earlier results from the Hadron-String Dynamics (HSD) approach - incorporating no explicit dynamical partonic phase - as well as to experimental data from the STAR, PHENIX, BRAHMS and PHOBOS collaborations for Au+Au collisions at the top RHIC energy...
Classical and relativistic flux of energy conservation in astrophysical jets
Zaninetti, L
2016-01-01
The conservation of the energy flux in turbulent jets which propagate in the intergalactic medium (IGM) allows deducing the law of motion in the classical and relativistic cases. Three types of IGM are considered: constant density, hyperbolic and inverse power law decrease of density. An analytical law for the evolution of the magnetic field along the radio-jets is deduced using a linear relation between the magnetic pressure and the rest density. Astrophysical applications are made to the centerline intensity of synchrotron emission in NGC315 and to the magnetic field of 3C273.
Bodmer, A.R. [Illinois Univ., Chicago, IL (United States). Dept. of Physics]|[Argonne National Lab., IL (United States); Usmani, Q.N.; Sami, M. [Jamia Millia Islamia, New Delhi (India). Dept. of Physics
1993-09-01
We consider the binding energies of {Lambda} hypernuclei (HN), in particular the single-particle (s.p.) energy data, which have been obtained for a wide range of HN with mass numbers A {le} 89 and for orbital angular momenta {ell}{sub {Lambda}} {le} 4. We briefly review some of the relevant properties of A hypernuclei. These are nuclei {sub {Lambda}}{sup A}Z with baryon number A in which a single {Lambda} hyperon (baryon number = 1) is bound to an ordinary nucleus {sup A}Z consisting of A - 1 nucleons = Z protons + N neutrons. The {Lambda} hyperon is neutral, has spin 1/2, strangeness S = {minus}1, isospin I = O and a mass M{sub {Lambda}} = 1116 MeV/c{sup 2}. Although the {Lambda} interacts with a nucleon, its interaction is only about half as strong as that between two nucleons, and thus very roughly V{sub {Lambda}N} {approx} 0.5 V{sub NN}. As a result, the two-body {Lambda}N system is unbound, and the lightest bound HN is the three-body hypertriton {sub {Lambda}}{sup 3}H in which the {Lambda} is bound to a deuteron with the {Lambda}-d separation energy being only {approx} 0.1 MeV corresponding to an exponential tail of radius {approx} 15 fm! In strong interactions the strangeness S is of course conserved, and the {Lambda} is distinct from the nucleons. In a HN strangeness changes only in the weak decays of the {Lambda} which can decay either via ``free`` pionic decay {Lambda} {yields} N + {pi} or via induced decay {Lambda} + N {yields} N + N which is only possible in the presence of nucleons. Because of the small energy release the pionic decay is strongly suppressed in all but the lightest HN and the induced decay dominates. However, the weak decay lifetime {approx} 10{sup {minus}10}s is in fact close to the lifetime of a free {Lambda}. Since this is much longer than the strong interaction time {approx} 10{sup {minus}22}s we can ignore the weak interactions when considering the binding of HN, just as for ordinary nuclei.
Relativistic dynamics of interacting point particles: Central position of the Wheeler-Feynman scheme
Costa de Beauregard, O.
1985-06-01
The Wheeler-Feynman (WF) relativistic theory of interacting point particles, generalized by acceptance of an arbitrary spacelike interaction, is shown to possess a privileged status, reminiscent of the “central force” interactions occurring in Newtonian mechanics. This scheme is shown to be isomorphic to the classical one of the statics of interacting flexible current-carrying wires obeying the Ampère-Laplace (AL) formulas: to the tension T (T 2 =const) of the wire corresponds the momentum-energy pi (pipi=-c2m2) of the particle; to the Laplace linear force density -i H×dr corresponds the Lorentz force QHij drj; to the Laplace potential ir-1 dr corresponds the WF potential Qδ(r2) dri, etc. Among the differences, there is self-action in the AL scheme and no self-action in the WF scheme. A stationary energy principle in the AL scheme is isomorphic to Fokker's stationary action principle in the WF scheme.
Khandelwal, Govind S.; Khan, Ferdous
1989-01-01
An optical model description of energy and momentum transfer in relativistic heavy-ion collisions, based upon composite particle multiple scattering theory, is presented. Transverse and longitudinal momentum transfers to the projectile are shown to arise from the real and absorptive part of the optical potential, respectively. Comparisons of fragment momentum distribution observables with experiments are made and trends outlined based on our knowledge of the underlying nucleon-nucleon interaction. Corrections to the above calculations are discussed. Finally, use of the model as a tool for estimating collision impact parameters is indicated.
Fluctuations in charged particle multiplicities in relativistic heavy-ion collisions
Mukherjee, Maitreyee; Basu, Sumit; Choudhury, Subikash; Nayak, Tapan K.
2016-08-01
Multiplicity distributions of charged particles and their event-by-event fluctuations have been compiled for relativistic heavy-ion collisions from the available experimental data at Brookhaven National Laboratory and CERN and also by the use of an event generator. Multiplicity fluctuations are sensitive to QCD phase transition and to the presence of a critical point in the QCD phase diagram. In addition, multiplicity fluctuations provide baselines for other event-by-event measurements. Multiplicity fluctuation expressed in terms of the scaled variance of the multiplicity distribution is an intensive quantity, but is sensitive to the volume fluctuation of the system. The importance of the choice of narrow centrality bins and the corrections of the centrality bin-width effect for controlling volume fluctuations have been discussed. It is observed that the mean and width of the multiplicity distributions monotonically increase as functions of increasing centrality at all collision energies, whereas the multiplicity fluctuations show minimal variations with centrality. The beam-energy dependence shows that the multiplicity fluctuations have a slow rise at lower collision energies and remain constant at higher energies.
High-energy emission from non-relativistic radiative shocks: application to gamma-ray novae
Vurm, Indrek
2016-01-01
Multiwavelength radiation from relativistic particles accelerated at shocks in novae and other astrophysical sources carries a wealth of information about the outflow properties and the microphysical processes at work near the shocks. The observation of GeV gamma-rays from novae by Fermi/LAT demonstrates that the shocks in these systems can accelerate particles to energies of at least $\\sim 10$ GeV. The low-energy extension of the same non-thermal particle distribution inevitably gives rise to emission extending into the X-ray band. Above $\\gtrsim 10$ keV this radiation can escape the system without significant absorption/attenuation, and can potentially be detected by NuSTAR. We present theoretical models for hard X-ray and gamma-ray emission from radiative shocks in both leptonic and hadronic scenarios, accounting for the rapid evolution of the downstream properties due to the fast cooling of thermal plasma. Due to strong Coulomb cooling of the mildly relativistic electrons nominally responsible for produci...
Bargsten, Clayton [Colorado State Univ., Fort Collins, CO (United States); Hollinger, Reed [Colorado State Univ., Fort Collins, CO (United States); Capeluto, Maria Gabriela [Univ. of Buenos Aires (Argentina); Kaymak, Vural [Heinrich Heine Univ., Dusseldorf (Germany); Pukhov, Alexander [Heinrich Heine Univ., Dusseldorf (Germany); Wang, Shoujun [Colorado State Univ., Fort Collins, CO (United States); Rockwood, Alex [Colorado State Univ., Fort Collins, CO (United States); Wang, Yong [Colorado State Univ., Fort Collins, CO (United States); Keiss, David [Colorado State Univ., Fort Collins, CO (United States); Tommasini, Riccardo [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); London, Richard [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Park, Jaebum [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Busquet, Michel [ARTEP Inc., Ellicott City, MD (United States); Klapisch, M [ARTEP Inc., Ellicott City, MD (United States); Shlyaptsev, Vyacheslav N. [Colorado State Univ., Fort Collins, CO (United States); Rocca, Jorge J. [Colorado State Univ., Fort Collins, CO (United States)
2016-11-11
Ultra-high-energy-density (UHED) matter, characterized by energy densities > 1 x 10^{8} J cm^{-3} and pressures greater than a gigabar, is encountered in the center of stars and in inertial confinement fusion capsules driven by the world’s largest lasers. Similar conditions can be obtained with compact, ultra-high contrast, femtosecond lasers focused to relativistic intensities onto targets composed of aligned nanowire arrays. Here we report the measurement of the key physical process in determining the energy density deposited in high aspect ratio nanowire array plasmas: the energy penetration. By monitoring the x-ray emission from buried Co tracer segments in Ni nanowire arrays irradiated at an intensity of 4 x 10^{19} W cm^{-2}, we demonstrate energy penetration depths of several μm, leading to UHED plasmas of that size. Relativistic 3D particle-in-cell-simulations, validated by these measurements, predict that irradiation of nanostructures at intensities of > 1 x 10^{22} W cm^{-2} will lead to a virtually unexplored extreme UHED plasma regime characterized by energy densities in excess of 8 x 10^{10} J cm^{-3}, equivalent to a pressure of 0.35 Tbar.
Bargsten, Clayton; Hollinger, Reed; Capeluto, Maria Gabriela; Kaymak, Vural; Pukhov, Alexander; Wang, Shoujun; Rockwood, Alex; Wang, Yong; Keiss, David; Tommasini, Riccardo; London, Richard; Park, Jaebum; Busquet, Michel; Klapisch, Marcel; Shlyaptsev, Vyacheslav N.; Rocca, Jorge J.
2017-01-01
Ultrahigh-energy density (UHED) matter, characterized by energy densities >1 × 108 J cm−3 and pressures greater than a gigabar, is encountered in the center of stars and inertial confinement fusion capsules driven by the world’s largest lasers. Similar conditions can be obtained with compact, ultrahigh contrast, femtosecond lasers focused to relativistic intensities onto targets composed of aligned nanowire arrays. We report the measurement of the key physical process in determining the energy density deposited in high-aspect-ratio nanowire array plasmas: the energy penetration. By monitoring the x-ray emission from buried Co tracer segments in Ni nanowire arrays irradiated at an intensity of 4 × 1019 W cm−2, we demonstrate energy penetration depths of several micrometers, leading to UHED plasmas of that size. Relativistic three-dimensional particle-in-cell simulations, validated by these measurements, predict that irradiation of nanostructures at intensities of >1 × 1022 W cm−2 will lead to a virtually unexplored extreme UHED plasma regime characterized by energy densities in excess of 8 × 1010 J cm−3, equivalent to a pressure of 0.35 Tbar. PMID:28097218
Bargsten, Clayton; Hollinger, Reed; Capeluto, Maria Gabriela; Kaymak, Vural; Pukhov, Alexander; Wang, Shoujun; Rockwood, Alex; Wang, Yong; Keiss, David; Tommasini, Riccardo; London, Richard; Park, Jaebum; Busquet, Michel; Klapisch, Marcel; Shlyaptsev, Vyacheslav N; Rocca, Jorge J
2017-01-01
Ultrahigh-energy density (UHED) matter, characterized by energy densities >1 × 10(8) J cm(-3) and pressures greater than a gigabar, is encountered in the center of stars and inertial confinement fusion capsules driven by the world's largest lasers. Similar conditions can be obtained with compact, ultrahigh contrast, femtosecond lasers focused to relativistic intensities onto targets composed of aligned nanowire arrays. We report the measurement of the key physical process in determining the energy density deposited in high-aspect-ratio nanowire array plasmas: the energy penetration. By monitoring the x-ray emission from buried Co tracer segments in Ni nanowire arrays irradiated at an intensity of 4 × 10(19) W cm(-2), we demonstrate energy penetration depths of several micrometers, leading to UHED plasmas of that size. Relativistic three-dimensional particle-in-cell simulations, validated by these measurements, predict that irradiation of nanostructures at intensities of >1 × 10(22) W cm(-2) will lead to a virtually unexplored extreme UHED plasma regime characterized by energy densities in excess of 8 × 10(10) J cm(-3), equivalent to a pressure of 0.35 Tbar.
Inoue, Yoshiyuki; Tanaka, Yasuyuki T.
2016-09-01
Relativistic jets launched by supermassive black holes, so-called active galactic nuclei (AGNs), are known as the most energetic particle accelerators in the universe. However, the baryon loading efficiency onto the jets from the accretion flows and their particle acceleration efficiencies have been veiled in mystery. With the latest data sets, we perform multi-wavelength spectral analysis of quiescent spectra of 13 TeV gamma-ray detected high-frequency-peaked BL Lacs (HBLs) following one-zone static synchrotron self-Compton (SSC) model. We determine the minimum, cooling break, and maximum electron Lorentz factors following the diffusive shock acceleration (DSA) theory. We find that HBLs have {P}B/{P}e˜ 6.3× {10}-3 and the radiative efficiency {ɛ }{{rad,jet}}˜ 6.7× {10}-4, where P B and P e is the Poynting and electron power, respectively. By assuming 10 leptons per one proton, the jet power relates to the black hole mass as {P}{{jet}}/{L}{{Edd}}˜ 0.18, where {P}{{jet}} and {L}{{Edd}} is the jet power and the Eddington luminosity, respectively. Under our model assumptions, we further find that HBLs have a jet production efficiency of {η }{{jet}}˜ 1.5 and a mass loading efficiency of {ξ }{{jet}}≳ 5× {10}-2. We also investigate the particle acceleration efficiency in the blazar zone by including the most recent Swift/BAT data. Our samples ubiquitously have particle acceleration efficiencies of {η }g˜ {10}4.5, which is inefficient to accelerate particles up to the ultra-high-energy-cosmic-ray (UHECR) regime. This implies that the UHECR acceleration sites should not be the blazar zones of quiescent low power AGN jets, if one assumes the one-zone SSC model based on the DSA theory.
Berrilli Francesco
2014-05-01
Full Text Available High-energy charged particles represent a severe radiation risk for astronauts and spacecrafts and could damage ground critical infrastructures related to space services. Different natural sources are the origin of these particles, among them galactic cosmic rays, solar energetic particles and particles trapped in radiation belts. Solar particle events (SPE consist in the emission of high-energy protons, alpha-particles, electrons and heavier particles from solar flares or shocks driven by solar plasma propagating through the corona and interplanetary space. Ground-level enhancements (GLE are rare solar events in which particles are accelerated to near relativistic energies and affect space and ground-based infrastructures. During the current solar cycle 24 a single GLE event was recorded on May 17th, 2012 associated with an M5.1-class solar flare. The investigation of such a special class of solar events permits us to measure conditions in space critical to both scientific and operational research. This event, classified as GLE71, was detected on board the International Space Station (ISS by the active particle detectors of the ALTEA (Anomalous Long Term Effects in Astronauts experiment. The collected data permit us to study the radiation environment inside the ISS. In this work we present the first results of the analysis of data acquired by ALTEA detectors during GLE71 associated with an M5.1-class solar flare. We estimate the energy loss spectrum of the solar particles and evaluate the contribution to the total exposure of ISS astronauts to solar high-energy charged particles.
HIGH ENERGY PARTICLE ACCELERATOR
Courant, E.D.; Livingston, M.S.; Snyder, H.S.
1959-04-14
An improved apparatus is presented for focusing charged particles in an accelerator. In essence, the invention includes means for establishing a magnetic field in discrete sectors along the path of moving charged particles, the magnetic field varying in each sector in accordance with the relation. B = B/ sub 0/ STAln (r-r/sub 0/)/r/sub 0/!, where B/sub 0/ is the value of the magnetic field at the equilibrium orbit of radius r/sub 0/ of the path of the particles, B equals the magnetic field at the radius r of the chamber and n equals the magnetic field gradient index, the polarity of n being abruptly reversed a plurality of times as the particles travel along their arcuate path. With this arrangement, the particles are alternately converged towards the axis of their equillbrium orbit and diverged therefrom in successive sectors with a resultant focusing effect.
Radiation from relativistic particles in nongeodesic motion in a strong gravitational field
Aliev, A.N. (AN Gruzinskoj SSR, Abastumani. Abastumanskaya Astrofizicheskaya Observatoriya); Galtsov, D.V. (Moskovskij Gosudarstvennyj Univ. (USSR). Kafedra Teoreticheskoj Fiziki)
1981-10-01
The scalar and electromagnetic radiation emitted by relativistic particles moving along the stable nongeodesic trajectories in the Kerr gravitational field are described. Two particular models of the nongeodesic motion are developed involving a slightly charged rotating black hole and a rotating black hole immersed in an external magnetic field.
Bakke, K.
2010-10-01
We obtain the solutions of the Dirac equation when the noninertial effects of the Fermi-Walker reference frame break the relativistic Landau-Aharonov-Casher quantization, but they provide bound states in an analogous way to a Dirac neutral particle subject to Tan-Inkson quantum dot potential [W.-C. Tan, J.C. Inkson, Semicond. Sci. Technol. 11 (1996) 1635].
Point-particle effective field theory III: relativistic fermions and the Dirac equation
Burgess, C. P.; Hayman, Peter; Rummel, Markus; Zalavári, László
2017-09-01
We formulate point-particle effective field theory (PPEFT) for relativistic spin-half fermions interacting with a massive, charged finite-sized source using a first-quantized effective field theory for the heavy compact object and a second-quantized language for the lighter fermion with which it interacts. This description shows how to determine the near-source boundary condition for the Dirac field in terms of the relevant physical properties of the source, and reduces to the standard choices in the limit of a point source. Using a first-quantized effective description is appropriate when the compact object is sufficiently heavy, and is simpler than (though equivalent to) the effective theory that treats the compact source in a second-quantized way. As an application we use the PPEFT to parameterize the leading energy shift for the bound energy levels due to finite-sized source effects in a model-independent way, allowing these effects to be fit in precision measurements. Besides capturing finite-source-size effects, the PPEFT treatment also efficiently captures how other short-distance source interactions can shift bound-state energy levels, such as due to vacuum polarization (through the Uehling potential) or strong interactions for Coulomb bound states of hadrons, or any hypothetical new short-range forces sourced by nuclei.
On relativistic motion of a pair of particles having opposite signs of masses
Ivanov, Pavel
2012-01-01
(abbreviated) In this note we consider, in a weak-field limit, a relativistic linear motion of two particles with opposite signs of masses having a small difference between their absolute values $m_{1,2}=\\pm (\\mu\\pm \\Delta \\mu) $, $\\mu > 0$, $|\\Delta \\mu | \\ll \\mu$ and a small difference between their velocities. Assuming that the weak-field limit holds and the dynamical system is conservative an elementary treatment of the problem based on the laws of energy and momentum conservation shows that the system can be accelerated indefinitely, or attain very large asymptotic values of the Lorentz factor $\\gamma$. The system experiences indefinite acceleration when its energy-momentum vector is null and the mass difference $\\Delta \\mu \\le 0$. When modulus of the square of the norm of the energy-momentum vector, $|N^2|$, is sufficiently small the system can be accelerated to very large $\\gamma \\propto |N^2|^{-1}$. It is stressed that when only leading terms in the ratio of a characteristic gravitational radius to th...
Radiation of Relativistic Particles in a Quasi-Homogeneous Magnetic Field
Epp, V
2016-01-01
Spectrum of radiation of a relativistic particle moving in a nonhomogeneous magnetic field is considered. The spectrum depends on the pitch-angle $\\alpha$ between the velocity direction and a line tangent to the field line. In case of very small $\\alpha$ the particle generates so-called curvature radiation, in an intermediate case undulator-kind radiation is produced. In this paper we present the calculations of radiation properties in a case when both curvature and undulator radiation is observed.
Relativistic wave equations for interacting massive particles with arbitrary half-intreger spins
Niederle, J
2001-01-01
New formulation of relativistic wave equations (RWE) for massive particles with arbitrary half-integer spins $s$ interacting with external electromagnetic fields are proposed. They are based on wave functions which are irreducible tensors of rank $2n$ ($n=s-\\frac12$) antisymmetric w.r.t. $n$ pairs of indices, whose components are bispinors. The form of RWE is straightforward and free of inconsistencies associated with the other approaches to equations describing interacting higher spin particles.
Gallo, Emanuel
2016-01-01
We present a general approach for the formulation of equations of motion for compact objects in general relativistic theories. The particle is assumed to be moving in a geometric background which in turn is asymptotically flat. By construction, the model incorporates the back reaction due to gravitational radiation generated by the motion of the particle. Our approach differs from other constructions tackling the same kind of problem.
Zhang, Ruili; He, Yang; Xiao, Jianyuan; Liu, Jian; Qin, Hong; Tang, Yifa
2016-01-01
Relativistic dynamics of a charged particle in time-dependent electromagnetic fields has theoretical significance and a wide range of applications. It is often multi-scale and requires accurate long-term numerical simulations using symplectic integrators. For modern large-scale particle simulations in complex, time-dependent electromagnetic field, explicit symplectic algorithms are much more preferable. In this paper, we treat the relativistic dynamics of a particle as a Hamiltonian system on the cotangent space of the space-time, and construct for the first time explicit symplectic algorithms for relativistic charged particles of order 2 and 3 using the sum-split technique and generating functions.
Nishikawa, K.-I.; Hartmann, D. H.; Hardee, P.; Hededal, C.; Mizunno, Y.; Fishman, G. J.
2006-01-01
We performed numerical simulations of particle acceleration, magnetic field generation, and emission from shocks in order to understand the observed emission from relativistic jets and supernova remnants. The investigation involves the study of collisionless shocks, where the Weibel instability is responsible for particle acceleration as well as magnetic field generation. A 3-D relativistic particle-in-cell (RPIC) code has been used to investigate the shock processes in electron-positron plasmas. The evolution of theWeibe1 instability and its associated magnetic field generation and particle acceleration are studied with two different jet velocities (0 = 2,5 - slow, fast) corresponding to either outflows in supernova remnants or relativistic jets, such as those found in AGNs and microquasars. Slow jets have intrinsically different structures in both the generated magnetic fields and the accelerated particle spectrum. In particular, the jet head has a very weak magnetic field and the ambient electrons are strongly accelerated and dragged by the jet particles. The simulation results exhibit jitter radiation from inhomogeneous magnetic fields, generated by the Weibel instability, which has different spectral properties than standard synchrotron emission in a homogeneous magnetic field.
Haba, Z
2009-02-01
We discuss relativistic diffusion in proper time in the approach of Schay (Ph.D. thesis, Princeton University, Princeton, NJ, 1961) and Dudley [Ark. Mat. 6, 241 (1965)]. We derive (Langevin) stochastic differential equations in various coordinates. We show that in some coordinates the stochastic differential equations become linear. We obtain momentum probability distribution in an explicit form. We discuss a relativistic particle diffusing in an external electromagnetic field. We solve the Langevin equations in the case of parallel electric and magnetic fields. We derive a kinetic equation for the evolution of the probability distribution. We discuss drag terms leading to an equilibrium distribution. The relativistic analog of the Ornstein-Uhlenbeck process is not unique. We show that if the drag comes from a diffusion approximation to the master equation then its form is strongly restricted. The drag leading to the Tsallis equilibrium distribution satisfies this restriction whereas the one of the Jüttner distribution does not. We show that any function of the relativistic energy can be the equilibrium distribution for a particle in a static electric field. A preliminary study of the time evolution with friction is presented. It is shown that the problem is equivalent to quantum mechanics of a particle moving on a hyperboloid with a potential determined by the drag. A relation to diffusions appearing in heavy ion collisions is briefly discussed.
Relativistic Killingbeck energy states under external magnetic fields
Eshghi, M. [Islamic Azad University, Researchers and Elite Club, Central Tehran Branch, Tehran (Iran, Islamic Republic of); Mehraban, H. [Semnan University, Faculty of Physics, Semnan (Iran, Islamic Republic of); Ikhdair, S.M. [An-Najah National University, Department of Physics, Faculty of Science, Nablus, West Bank, Palestine (Country Unknown); Near East University, Department of Electrical Engineering, Nicosia, Northern Cyprus (Turkey)
2016-07-15
We address the behavior of the Dirac equation with the Killingbeck radial potential including the external magnetic and Aharonov-Bohm (AB) flux fields. The spin and pseudo-spin symmetries are considered. The correct bound state spectra and their corresponding wave functions are obtained. We seek such a solution using the biconfluent Heun's differential equation method. Further, we give some of our results at the end of this study. Our final results can be reduced to their non-relativistic forms by simply using some appropriate transformations. The spectra, in the spin and pseudo-spin symmetries, are very similar with a slight difference in energy spacing between different states. (orig.)
Particle acceleration in explosive relativistic reconnection events and Crab Nebula gamma-ray flares
Lyutikov, Maxim; Komissarov, Sergey; Porth, Oliver
2016-01-01
We develop a model of particle acceleration in explosive reconnection events in relativistic magnetically-dominated plasmas and apply it to explain gamma-ray flares from the Crab Nebula. The model relies on development of current-driven instabilities on macroscopic scales (not related to plasma skin depths). Using analytical and numerical methods (fluid and particle-in-cell simulations), we study a number of model problems in relativistic magnetically-dominated plasma: (i) we extend Syrovatsky's classical model of explosive X-point collapse to magnetically-dominated plasmas; (ii) we consider instability of two-dimensional force-free system of magnetic flux tubes; (iii) we consider merger of two zero total poloidal current magnetic flux tubes. In all cases regimes of spontaneous and driven evolution are investigated. We identify two stages of particle acceleration: (i) fast explosive prompt X-point collapse and (ii) ensuing island merger. The fastest acceleration occurs during the initial catastrophic X-point ...
Parton-Hadron-String Dynamics at relativistic collider energies
Bratkovskaya, E. L.; Cassing, W.; Konchakovski, V. P.; Linnyk, O.
2011-04-01
The novel Parton-Hadron-String Dynamics (PHSD) transport approach is applied to nucleus-nucleus collisions at RHIC energies with respect to differential hadronic spectra in comparison to available data. The PHSD approach is based on a dynamical quasiparticle model for partons (DQPM) matched to reproduce recent lattice-QCD results from the Wuppertal-Budapest group in thermodynamic equilibrium. The transition from partonic to hadronic degrees of freedom is described by covariant transition rates for the fusion of quark-antiquark pairs or three quarks (antiquarks), respectively, obeying flavor current-conservation, color neutrality as well as energy-momentum conservation. Our dynamical studies for heavy-ion collisions at relativistic collider energies are compared to earlier results from the Hadron-String Dynamics (HSD) approach - incorporating no explicit dynamical partonic phase - as well as to experimental data from the STAR, PHENIX, BRAHMS and PHOBOS Collaborations for Au + Au collisions at the top RHIC energy of √{s}=200 GeV. We find a reasonable reproduction of hadron rapidity distributions and transverse mass spectra and also a fair description of the elliptic flow of charged hadrons as a function of the centrality of the reaction and the transverse momentum p. Furthermore, an approximate quark-number scaling of the elliptic flow v of hadrons is observed in the PHSD results, too.
Parton-Hadron-String Dynamics at relativistic collider energies
Bratkovskaya, E.L., E-mail: Elena.Bratkovskaya@th.physik.uni-frankfurt.d [Institut fuer Theoretische Physik, JWG Universitaet Frankfurt, D-60438 Frankfurt am Main (Germany); Frankfurt Institut for Advanced Studies, Frankfurt University, D-60438 Frankfurt-am-Main (Germany); Cassing, W.; Konchakovski, V.P. [Institut fuer Theoretische Physik, Universitaet Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen (Germany); Linnyk, O. [Frankfurt Institut for Advanced Studies, Frankfurt University, D-60438 Frankfurt-am-Main (Germany)
2011-04-15
The novel Parton-Hadron-String Dynamics (PHSD) transport approach is applied to nucleus-nucleus collisions at RHIC energies with respect to differential hadronic spectra in comparison to available data. The PHSD approach is based on a dynamical quasiparticle model for partons (DQPM) matched to reproduce recent lattice-QCD results from the Wuppertal-Budapest group in thermodynamic equilibrium. The transition from partonic to hadronic degrees of freedom is described by covariant transition rates for the fusion of quark-antiquark pairs or three quarks (antiquarks), respectively, obeying flavor current-conservation, color neutrality as well as energy-momentum conservation. Our dynamical studies for heavy-ion collisions at relativistic collider energies are compared to earlier results from the Hadron-String Dynamics (HSD) approach - incorporating no explicit dynamical partonic phase - as well as to experimental data from the STAR, PHENIX, BRAHMS and PHOBOS Collaborations for Au + Au collisions at the top RHIC energy of {radical}(s)=200 GeV. We find a reasonable reproduction of hadron rapidity distributions and transverse mass spectra and also a fair description of the elliptic flow of charged hadrons as a function of the centrality of the reaction and the transverse momentum p{sub T}. Furthermore, an approximate quark-number scaling of the elliptic flow v{sub 2} of hadrons is observed in the PHSD results, too.
Andrade, R.P.G. [Instituto de Fisica, Universidade de Sao Paulo (Brazil); Grassi, F., E-mail: grassi@if.usp.br [Instituto de Fisica, Universidade de Sao Paulo (Brazil); Hama, Y. [Instituto de Fisica, Universidade de Sao Paulo (Brazil); Qian, W.-L. [Instituto de Ciencias Exatas, Universidade Federal de Ouro Preto (Brazil)
2012-06-06
Relativistic nuclear collisions data on two-particle correlations exhibit structures as function of relative azimuthal angle and rapidity. A unified description of these near-side and away-side structures is proposed for low to moderate transverse momentum. It is based on the combined effect of tubular initial conditions and hydrodynamical expansion. Contrary to expectations, the hydrodynamics solution shows that the high-energy density tubes (leftover from the initial particle interactions) give rise to particle emission in two directions and this is what leads to the various structures. This description is sensitive to some of the initial tube parameters and may provide a probe of the strong interaction. This explanation is compared with an alternative one where some triangularity in the initial conditions is assumed. A possible experimental test is suggested.
Vayenas, C. G.; Fokas, A. S.; Grigoriou, D.
2016-08-01
We compute analytically the masses, binding energies and hamiltonians of gravitationally bound Bohr-type states via the rotating relativistic lepton model which utilizes the de Broglie wavelength equation in conjunction with special relativity and Newton's relativistic gravitational law. The latter uses the inertial-gravitational masses, rather than the rest masses, of the rotating particles. The model also accounts for the electrostatic charge- induced dipole interactions between a central charged lepton, which is usually a positron, with the rotating relativistic lepton ring. We use three rotating relativistic neutrinos to model baryons, two rotating relativistic neutrinos to model mesons, and a rotating relativistic electron neutrino - positron (or electron) pair to model the W± bosons. It is found that gravitationally bound ground states comprising three relativistic neutrinos have masses in the baryon mass range (∼⃒ 0.9 to 1 GeV/c2), while ground states comprising two neutrinos have masses in the meson mass range (∼⃒ 0.4 to 0.8 GeV/c2). It is also found that the rest mass values of quarks are in good agreement with the heaviest neutrino mass value of 0.05 eV/c2 and that the mass of W± bosons (∼⃒ 81 GeV/c2) corresponds to the mass of a rotating gravitationally confined e± — ve pair. A generalized expression is also derived for the gravitational potential energy of such relativistic Bohr-type structures.
Radial equilibrium of relativistic particle bunches in plasma wakefield accelerators
Lotov, K V
2016-01-01
Drive particle beams in linear or weakly nonlinear regimes of the plasma wakefield accelerator quickly reach a radial equilibrium with the wakefield, which is described in detail for the first time. The equilibrium beam state and self-consistent wakefields are obtained by combining analytical relationships, numerical integration, and first-principle simulations. In the equilibrium state, the beam density is strongly peaked near the axis, the beam radius is constant along the beam, and longitudinal variation of the focusing strength is balanced by varying beam emittance. The transverse momentum distribution of beam particles depends on the observation radius and is neither separable, nor Gaussian.
Coaxial charged particle energy analyzer
Kelly, Michael A. (Inventor); Bryson, III, Charles E. (Inventor); Wu, Warren (Inventor)
2011-01-01
A non-dispersive electrostatic energy analyzer for electrons and other charged particles having a generally coaxial structure of a sequentially arranged sections of an electrostatic lens to focus the beam through an iris and preferably including an ellipsoidally shaped input grid for collimating a wide acceptance beam from a charged-particle source, an electrostatic high-pass filter including a planar exit grid, and an electrostatic low-pass filter. The low-pass filter is configured to reflect low-energy particles back towards a charged particle detector located within the low-pass filter. Each section comprises multiple tubular or conical electrodes arranged about the central axis. The voltages on the lens are scanned to place a selected energy band of the accepted beam at a selected energy at the iris. Voltages on the high-pass and low-pass filters remain substantially fixed during the scan.
Ellison, Donald C.; Warren, Donald C.; Bykov, Andrei M.
2016-03-01
We include a general form for the scattering mean free path, λmfp(p), in a nonlinear Monte Carlo model of relativistic shock formation and Fermi acceleration. Particle-in-cell simulations, as well as analytic work, suggest that relativistic shocks tend to produce short-scale, self-generated magnetic turbulence that leads to a scattering mean free path with a stronger momentum dependence than the λmfp ∝ p dependence for Bohm diffusion. In unmagnetized shocks, this turbulence is strong enough to dominate the background magnetic field so the shock can be treated as parallel regardless of the initial magnetic field orientation, making application to γ-ray bursts, pulsar winds, type Ibc supernovae, and extragalactic radio sources more straightforward and realistic. In addition to changing the scale of the shock precursor, we show that, when nonlinear effects from efficient Fermi acceleration are taken into account, the momentum dependence of λmfp(p) has an important influence on the efficiency of cosmic ray production as well as the accelerated particle spectral shape. These effects are absent in non-relativistic shocks and do not appear in relativistic shock models unless nonlinear effects are self-consistently described. We show, for limited examples, how the changes in Fermi acceleration translate to changes in the intensity and spectral shape of γ-ray emission from proton-proton interactions and pion-decay radiation.
Ultra-relativistic spinning particle and a rotating body in external fields
Deriglazov, Alexei A
2015-01-01
We use the vector model of spinning particle to analyze the influence of spin-field coupling on the particle's trajectory in ultra-relativistic regime. The Lagrangian with minimal spin-gravity interaction yields the equations equivalent to the Mathisson-Papapetrou-Tulczyjew-Dixon (MPTD) equations of a rotating body. We show that they have unsatisfactory behavior in the ultra-relativistic limit. In particular, three-dimensional acceleration of the particle increases with velocity and becomes infinite in the limit. The reason is that in the equation for trajectory emerges the term which can be thought as an effective metric generated by the minimal spin-gravity coupling. Therefore we examine the non-minimal interaction through the gravimagnetic moment $\\kappa$, and show that the theory with $\\kappa=1$ is free of the problems detected in MPTD-equations. Hence the non-minimally interacting theory seem more promising candidate for description of a relativistic rotating body. The Lagrangian for the particle in an a...
Entanglement of two relativistic particles with discrete momenta
Palge, Veiko; Dunningham, Jacob
2014-01-01
We study the structure of maps that Lorentz boosts induce on the spin degree of freedom of a system consisting of two massive spin-$1/2$ particles. We consider the case where the spin state is described by the Werner state and the momenta are discrete. Transformations on the spins are systematically investigated in various boost scenarios by calculating the orbit and concurrence of the bipartite spin state with different kinds of product and entangled momenta. We confirm the general conclusio...
Shukla, Chandrasekhar; Patel, Kartik
2016-01-01
We carry out Particle-in-Cell (PIC) simulations to study the instabilities associated with a 2-D sheared electron flow configuration against a neutralizing background of ions. Both weak and strong relativistic flow velocities are considered. In the weakly relativistic case, we observe the development of electromagnetic Kelvin Helmholtz instability with similar characteristics as that predicted by the electron Magnetohydrodynamic (EMHD) model. On other hand, in strong relativistic case the compressibility effects of electron fluid dominate and introduce upper hybrid electrostatic oscillations transverse to the flow which are very distinct from EMHD fluid behaviour. In the nonlinear regime, both weak and strong relativistic cases lead to turbulence with broad power law spectrum.
Geodesic motions of test particles in a relativistic core-shell spacetime
Liu, Lei; Wu, Xin; Huang, Guoqing
2017-02-01
In this paper, we discuss the geodesic motions of test particles in the intermediate vacuum between a monopolar core and an exterior shell of dipoles, quadrupoles and octopoles. The radii of the innermost stable circular orbits at the equatorial plane depend only on the quadrupoles. A given oblate quadrupolar leads to the existence of two innermost stable circular orbits, and their radii are larger than in the Schwarzschild spacetime. However, a given prolate quadrupolar corresponds to only one innermost stable circular orbit, and its radius is smaller than in the Schwarzschild spacetime. As to the general geodesic orbits, one of the recently developed extended phase space fourth order explicit symplectic-like methods is efficiently applicable to them although the Hamiltonian of the relativistic core-shell system is not separable. With the aid of both this fast integrator without secular growth in the energy errors and gauge invariant chaotic indicators, the effect of these shell multipoles on the geodesic dynamics of order and chaos is estimated numerically.
Energy and Centrality Dependences of Charged Multiplicity Density in Relativistic Nuclear Collisions
SA; Ben-hao; Bonasera; A; TAI; An
2002-01-01
Using a hadron and string cascade model, JPCIAE, the energy and centrality dependences of chargedparticle pseudo rapidity density in relativistic nuclear collisions were studied. Within the framework ofthis model, both the relativistic p + p experimental data and the PHOBOS and PHENIX Au + Au data at
Self-modulated dynamics of a relativistic charged particle beam in plasma wake field excitation
Akhter, T.; Fedele, R. [Dipartimento di Fisica ‘Ettore Pancini’, Università di Napoli Federico II and INFN Sezione di Napoli, Napoli (Italy); Nicola, S. De [CNR-SPIN and INFN Sezione di Napoli, Napoli (Italy); Tanjia, F. [Dipartimento di Fisica ‘Ettore Pancini’, Università di Napoli Federico II and INFN Sezione di Napoli, Napoli (Italy); Jovanović, D. [Institute of Physics, University of Belgrade, Belgrade (Serbia); Mannan, A. [Department of Physics, Jahangirnagar University, Savar, Dhaka (Bangladesh)
2016-09-01
The self-modulated dynamics of a relativistic charged particle beam is provided within the context of the theory of plasma wake field excitation. The self-consistent description of the beam dynamics is provided by coupling the Vlasov equation with a Poisson-type equation relating the plasma wake potential to the beam density. An analysis of the beam envelope self-modulation is then carried out and the criteria for the occurrence of the instability are discussed thereby.
Berard, A.; Grandati, Y.; Mohrbach, H. [Universite Paul Verlaine, Institut de Physique, Laboratoire de Physique Moleculaire et des Collisions, ICPMB, IF CNRS 2843, Metz, Cedex 3 (France); Ghosh, Subir [Indian Statistical Institute, Physics and Applied Mathematics Unit, Kolkata (India); Pal, Probir [S.N. Bose National Centre for Basic Sciences, Kolkata (India)
2011-11-15
In this paper we have considered the dynamics of an anomalous (g{ne}2) charged relativistic spinning particle in the presence of an external electromagnetic field. A constraint analysis is done and the complete set of Dirac brackets are provided that generate the canonical Lorentz algebra and dynamics through Hamiltonian equations of motion. The spin-induced effective curvature of spacetime and its possible connection with Analogue Gravity models are commented upon. (orig.)
Relativistic Dirac equation for particles with arbitrary half-integral spin
Guseinov, I I
2008-01-01
The sets of 2(2s+1)-component matrices through the four-component Dirac matrices are suggested, where s=3/2, 5/2,.... Using these matrices sets the Dirac relativistic equation for a description of arbitrary half-integral spin particles is constructed. The new Dirac equation of motion leads to an equation of continuity with a positive-definite probability density.
Energy dependence of resonance production in relativistic heavy ion collisions
Shao, Feng-lan; Wang, Rui-qin; Zhang, Mao-sheng
2016-01-01
The production of hadronic resonances $K^{*}(892)$, $\\phi(1020)$, $\\Sigma^{*}(1385)$, and $\\Xi^{*}(1530)$ in central AA collisions at $\\sqrt{s_{NN}}=$ 17.3, 200, and 2760 GeV are systematically studied. The direct production of these resonances at system hadronization are described by the quark combination model and the effects of hadron multiple-scattering stage are dealt with by a ultra-relativistic quantum molecular dynamics model (UrQMD). We study the contribution of these two production sources to final observation and compare the final spectra with the available experimental data. The $p_T$ spectra of $K^{*}(892)$ calculated directly by quark combination model are explicitly higher than the data at low $p_T \\lesssim 1.5$ GeV and taking into account the modification of rescattering effects the resulting final spectra well agree with the data at all three collision energies. The rescattering effect on $\\phi(1020)$ production is weak and including it can slightly improve our description at low $p_T$ on the...
Energy dependence of resonance production in relativistic heavy ion collisions
Shao, Feng-Lan; Song, Jun; Wang, Rui-Qin; Zhang, Mao-Sheng
2017-01-01
The production of the hadronic resonances K*0(892), ϕ(1020), Σ*(1385), and Ξ*(1530) in central AA collisions at , 200, and 2760 GeV is systematically studied. The direct production of these resonances at system hadronization is described by the quark combination model and the effects of hadron multiple-scattering stage are dealt with by a ultra-relativistic quantum molecular dynamics model (UrQMD). We study the contribution of these two production sources to final observation and compare the final spectra with the available experimental data. The p T spectra of K*0(892) calculated directly by quark combination model are explicitly higher than the data at low p T ≲ 1.5 GeV, and taking into account the modification of rescattering effects, the resulting final spectra well agree with the data at all three collision energies. The rescattering effect on ϕ(1020) production is weak and including it can slightly improve our description at low p T on the basis of overall agreement with the data. We also predict the p T spectra of Σ*(1385) and Ξ*(1530), to be tested by the future experimental data. Supported by National Natural Science Foundation of China (11575100, 11305076, 11505104)
Cosmology as Relativistic Particle Mechanics: From Big Crunch to Big Bang
Russo, J G
2004-01-01
Cosmology can be viewed as geodesic motion in an appropriate metric on an `augmented' target space; here we obtain these geodesics from an effective relativistic particle action. As an application, we find some exact (flat and curved) cosmologies for models with N scalar fields taking values in a hyperbolic target space for which the augmented target space is a Milne universe. The singularities of these cosmologies correspond to points at which the particle trajectory crosses the Milne horizon, suggesting a novel resolution of them, which we explore via the Wheeler-deWitt equation.
Relativistic dynamics of cylindrical shells of counter-rotating particles
Hamity, V H; Barraco, D E
2007-01-01
Although infinite cylinders are not astrophysical entities, it is possible to learn a great deal about the basic qualitative features of generation of gravitational waves and the behavior of the matter conforming such shells in the limits of very small radius. We describe the analytical model using kinetic theory for the matter and the junction conditions through the shell to obtain its equation of motion. The nature of the static solutions are analyzed, both for a single shell as well as for two concentric shells. In this second case, for a time dependent external shell, we integrate numerically the equation of motion for several values of the constants of the system. Also, a brief description in terms of the Komar mass is given to account for the gravitational wave energy emitted by the system.
Physical stress, mass, and energy for non-relativistic spinful matter
Geracie, Michael; Roberts, Matthew M
2016-01-01
For theories of relativistic matter fields with spin there exist two possible definitions of the stress-energy tensor, one defined by a variation of the action with the coframes at fixed connection, and the other at fixed torsion. These two stress-energy tensors do not necessarily coincide and it is the latter that corresponds to the Cauchy stress measured in the lab. In this note we discuss the corresponding issue for non-relativistic matter theories. We point out that while the physical non-relativistic stress, momentum, and mass currents are defined by a variation of the action at fixed torsion, the energy current does not admit such a description and is naturally defined at fixed connection. Any attempt to define an energy current at fixed torsion results in an ambiguity which cannot be resolved from the background spacetime data or conservation laws. We also provide computations of these quantities for some simple non-relativistic actions.
Energy losses of positive and negative charged particles in electron gas
Diachenko, M. M.; Kholodov, R. I.
2017-02-01
A heavy charged particle propagation through electron gas has been studied using combination of non-relativistic quantum mechanics and the Green’s functions method. The energy loss of a charged particle has been found in the case of large transferred momentum taking into account the interference term in the expression for the rate. The dependence of the energy loss of a charged particles in electron gas with nonzero temperature on the sign of the charge has been obtained.
Quantum Geometry: Relativistic energy approach to cooperative electron-nucleary-transition spectrum
Ольга Юрьевна Хецелиус
2014-11-01
Full Text Available An advanced relativistic energy approach is presented and applied to calculating parameters of electron-nuclear 7-transition spectra of nucleus in the atom. The intensities of the spectral satellites are defined in the relativistic version of the energy approach (S-matrix formalism, and gauge-invariant quantum-electrodynamical perturbation theory with the Dirac-Kohn-Sham density-functional zeroth approximation.
Relativistic ponderomotive Hamiltonian of a Dirac particle in a vacuum laser field
Ruiz, D E; Dodin, I Y
2015-01-01
We report a point-particle ponderomotive model of a Dirac electron oscillating in a high-frequency field. Starting from the Dirac Lagrangian density, we derive a reduced phase-space Lagrangian that describes the relativistic time-averaged dynamics of such a particle in a geometrical optics laser pulse propagating in vacuum. The pulse is allowed to have an arbitrarily large amplitude (provided radiation damping and pair production are negligible) and a wavelength comparable to the particle de Broglie wavelength. The model captures the Bargmann-Michel-Telegdi (BMT) spin dynamics, the Stern-Gerlach spin-orbital coupling, the conventional ponderomotive forces, and the interaction with large-scale background fields. Agreement with the BMT spin precesison equation is shown numerically. The commonly known theory, in which ponderomotive effects are incorporated in the particle effective mass, is reproduced as a special case when the spin-orbital coupling is negligible. This model could be useful for studying laser-pl...
Relativistic effects in two-particle emission for electron and neutrino reactions
Simo, I Ruiz; Amaro, J E; Barbaro, M B; Caballero, J A; Donnelly, T W
2014-01-01
Two-particle two-hole contributions to electroweak response functions are computed in a fully relativistic Fermi gas, assuming that the electroweak current matrix elements are independent of the kinematics. We analyze the genuine kinematical and relativistic effects before including a realistic meson-exchange current (MEC) operator. This allows one to study the mathematical properties of the non-trivial seven-dimensional integrals appearing in the calculation and to design an optimal numerical procedure to reduce the computation time. This is required for practical applications to CC neutrino scattering experiments, where an additional integral over the neutrino flux is performed. A check of the feasibility of this model using a more realistic current operator is presented for the case of the contact term of the electroweak MEC.
Quantum-mechanical description of Lense-Thirring effect for relativistic scalar particles
Silenko, Alexander J
2014-01-01
Exact expression for the Foldy-Wouthuysen Hamiltonian of scalar particles is used for a quantum-mechanical description of the relativistic Lense-Thirring effect. The exact evolution of the angular momentum operator in the Kerr field approximated by a spatially isotropic metric is found. The quantum-mechanical description of the full Lense-Thirring effect based on the Laplace-Runge-Lenz vector is given in the nonrelativistic and weak-field approximation. Relativistic quantum-mechanical equations for the velocity and acceleration operators are obtained. The equation for the acceleration defines the Coriolis-like and centrifugal-like accelerations and presents the quantum-mechanical description of the frame-dragging effect.
Ellison, Donald C; Bykov, Andrei M
2015-01-01
We include a general form for the scattering mean free path in a nonlinear Monte Carlo model of relativistic shock formation and Fermi acceleration. Particle-in-cell (PIC) simulations, as well as analytic work, suggest that relativistic shocks tend to produce short-scale, self-generated magnetic turbulence that leads to a scattering mean free path (mfp) with a stronger momentum dependence than the mfp ~ p dependence for Bohm diffusion. In unmagnetized shocks, this turbulence is strong enough to dominate the background magnetic field so the shock can be treated as parallel regardless of the initial magnetic field orientation, making application to gamma-ray bursts (GRBs), pulsar winds, Type Ibc supernovae, and extra-galactic radio sources more straightforward and realistic. In addition to changing the scale of the shock precursor, we show that, when nonlinear effects from efficient Fermi acceleration are taken into account, the momentum dependence of the mfp has an important influence on the efficiency of cosm...
Particle-in-cell Simulations of Global Relativistic Jets with Helical Magnetic Fields
Duţan, Ioana; Mizuno, Yosuke; Niemiec, Jacek; Kobzar, Oleh; Pohl, Martin; Gómez, Jose L; Pe'er, Asaf; Frederiksen, Jacob T; Nordlund, Åke; Meli, Athina; Sol, Helene; Hardee, Philip E; Hartmann, Dieter H
2016-01-01
We study the interaction of relativistic jets with their environment, using 3-dimensional relativistic particle-in-cell simulations for two cases of jet composition: (i) electron-proton ($e^{-}-p^{+}$) and (ii) electron-positron ($e^{\\pm}$) plasmas containing helical magnetic fields. We have performed simulations of "global" jets containing helical magnetic fields in order to examine how helical magnetic fields affect kinetic instabilities such as the Weibel instability, the kinetic Kelvin-Helmholtz instability and the Mushroom instability. We have found that these kinetic instabilities are suppressed and new types of instabilities can grow. For the $e^{-}-p^{+}$ jet, a recollimation-like instability occurs and jet electrons are strongly perturbed, whereas for the $e^{\\pm}$ jet, a recollimation-like instability occurs at early times followed by kinetic instability and the general structure is similar to a simulation without a helical magnetic field. We plan to perform further simulations using much larger sys...
Cheung, C.C.Teddy; Stawarz, L.; Harris, D.E.; Ostrowski, M.
2007-10-15
We report new detections of the hotspots in Cygnus A at 4.5 and 8.0 microns with the Spitzer Space Telescope. Together with detailed published radio observations and synchrotron self-Compton modeling of previous X-ray detections, we reconstruct the underlying electron energy spectra of the two brightest hotspots (A and D). The low-energy portion of the electron distributions have flat power-law slopes (s {approx} 1.5) up to the break energy which corresponds almost exactly to the mass ratio between protons and electrons; we argue that these features are most likely intrinsic rather than due to absorption effects. Beyond the break, the electron spectra continue to higher energies with very steep slopes s>3. Thus, there is no evidence for the 'canonical' s=2 slope expected in 1st order Fermi-type shocks within the whole observable electron energy range. We discuss the significance of these observations and the insight offered into high-energy particle acceleration processes in mildly relativistic shocks.
``Pheudo-cyclotron'' radiation of non-relativistic particles in small-scale magnetic turbulence
Keenan, Brett; Ford, Alex; Medvedev, Mikhail V.
2014-03-01
Plasma turbulence in some astrophysical objects (e.g., weakly magnetized collisionless shocks in GRBs and SN) has small-scale magnetic field fluctuations. We study spectral characteristics of radiation produced by particles moving in such turbulence. It was shown earlier that relativistic particles produce jitter radiation, which spectral characteristics are markedly different from synchrotron radiation. Here we study radiation produced by non-relativistic particles. In the case of a homogeneous fields, such radiation is cyclotron and its spectrum consists of just a single harmonic at the cyclotron frequency. However, in the sub-Larmor-scale turbulence, the radiation spectrum is much reacher and reflects statistical properties of the underlying magnetic field. We present both analytical estimates and results of ab initio numerical simulations. We also show that particle propagation in such turbulence is diffusive and evaluate the diffusion coefficient. We demonstrate that the diffusion coefficient correlates with some spectral parameters. These results can be very valuable for remote diagnostics of laboratory and astrophysical plasmas. Supported by grant DOE grant DE-FG02-07ER54940 and NSF grant AST-1209665.
Quasiclassical propagator of a relativistic particle via the path-dependent gauge potential
Yakaboylu, Enderalp; Hatsagortsyan, Karen Z.; Keitel, Christoph H. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany)
2016-07-01
The proper time formalism for a particle propagator in an external electromagnetic field is combined with the path-dependent formulation of gauge theory to simplify the quasiclassical propagator of a relativistic particle. The latter is achieved due to a specific choice of gauge corresponding to the use of the classical path in the path-dependent formulation of gauge theory, which leads to cancellation of the interaction part of the classical action in the Feynman path integral. A simple expression for the quasiclassical propagator is obtained in all cases of the external field when the classical equations of motion in this field are integrable. As an example, simple expressions for the propagators are derived for a spinless charged particle interacting with the following fields: an arbitrary constant and uniform electromagnetic field, an arbitrary plane wave, and finally an arbitrary plane wave combined with an arbitrary constant and uniform electromagnetic field. In all these cases the quasiclassical propagator coincides with the exact result.
Calibration of ionization energy loss at relativistic rise with STAR Time Projection Chamber
Xu, Yichun; Bichsel, Hans; Dong, Xin; Fachini, Patricia; Fisyak, Yuri; Kocolosky, Adam; Mohanty, Bedanga; Netrakanti, Pawan; Ruan, Lijuan; Suarez, Maria Cristina; Tang, Zebo; van Buren, Gene; Xu, Zhangbu
2008-01-01
We derive a method to improve particle identification (PID) at high transverse momentum ($p_T$) using the relativistic rise of the ionization energy loss ($rdE/dx$) when charged particles traverse the Time Projection Chamber (TPC) at STAR. Electrons triggered and identified by the Barrel Electro-Magnetic Calorimeter (BEMC), pure protons and pions from $\\Lambda\\to p+\\pi^{-}$ ($\\bar{\\Lambda}\\to \\bar{p}+\\pi^{+}$), and $K^{0}_{S}\\to\\pi^{+}+\\pi^{-}$ decays are used to obtain the $dE/dx$ value and its width at given $\\beta\\gamma=p/m$. We found that the deviation of the $dE/dx$ from the Bichsel function can be up to $0.4\\sigma$ ($\\sim3%$) in p+p collisions at $\\sqrt{s_{NN}}=200$ GeV taken and subsequently calibrated in year 2005. The deviation is approximately a function of $\\beta\\gamma$ independent of particle species and can be described with a function of $f(x) = A+\\frac{B}{C+x^{2}}$. The deviations obtained with this method are used to re-calibrate the data sample from p+p collision for physics analysis of ident...
Relativistic ponderomotive Hamiltonian of a Dirac particle in a vacuum laser field
Ruiz, D. E.; Ellison, C. L.; Dodin, I. Y.
2015-12-01
We report a point-particle ponderomotive model of a Dirac electron oscillating in a high-frequency field. Starting from the Dirac Lagrangian density, we derive a reduced phase-space Lagrangian that describes the relativistic time-averaged dynamics of such a particle in a geometrical-optics laser pulse propagating in vacuum. The pulse is allowed to have an arbitrarily large amplitude provided that radiation damping and pair production are negligible. The model captures the Bargmann-Michel-Telegdi (BMT) spin dynamics, the Stern-Gerlach spin-orbital coupling, the conventional ponderomotive forces, and the interaction with large-scale background fields (if any). Agreement with the BMT spin precession equation is shown numerically. The commonly known theory in which ponderomotive effects are incorporated in the particle effective mass is reproduced as a special case when the spin-orbital coupling is negligible. This model could be useful for studying laser-plasma interactions in relativistic spin-1 /2 plasmas.
Wallin, Erik; Gonoskov, Arkady; Marklund, Mattias
2015-03-01
We model the emission of high energy photons due to relativistic charged particle motion in intense laser-plasma interactions. This is done within a particle-in-cell code, for which high frequency radiation normally cannot be resolved due to finite time steps and grid size. A simple expression for the synchrotron radiation spectra is used together with a Monte-Carlo method for the emittance. We extend previous work by allowing for arbitrary fields, considering the particles to be in instantaneous circular motion due to an effective magnetic field. Furthermore, we implement noise reduction techniques and present validity estimates of the method. Finally, we perform a rigorous comparison to the mechanism of radiation reaction, and find the emitted energy to be in excellent agreement with the losses calculated using radiation reaction.
Wallin, Erik; Marklund, Mattias
2014-01-01
We model the emission of high energy photons due to relativistic particles in a plasma interacting with a super-intense laser. This is done in a particle-in-cell code where the high frequency radiation normally cannot be resolved, due to the unattainable demands it would place on the time and space resolution. A simple expression for the synchrotron radiation spectra is used together with a Monte-Carlo method for the emittance. We extend to previous work by accounting acceleration due to arbitrary fields, considering the particles to be in instantaneous circular motion due to an effective magnetic field. Furthermore we implement noise reduction techniques and present estimations of the validity of the method. Finally we perform a rigorous comparison to the mechanism of radiation reaction, with the emitted energy very well in agreement with the radiation reaction loss.
From physical principles to relativistic classical Hamiltonian and Lagrangian particle mechanics
Carcassi, Gabriele
2015-01-01
We show that classical particle mechanics (Hamiltonian and Lagrangian consistent with relativistic electromagnetism) can be derived from three fundamental assumptions: infinite reducibility, deterministic and reversible evolution, and kinematic equivalence. The core idea is that deterministic and reversible systems preserve the cardinality of a set of states, which puts considerable constraints on the equations of motion. This perspective links different concepts from different branches of math and physics (e.g. cardinality of a set, cotangent bundle for phase space, Hamiltonian flow, locally Minkowskian space-time manifold), providing new insights. The derivation strives to use definitions and mathematical concepts compatible with future extensions to field theories and quantum mechanics.
Melekhin, V. N.
1997-02-01
It is shown that the transverse momentum imparted to a relativistic particle, passing through an accelerating cavity near and parallel to its axis ( z-axis), may be presented as a trajectory integral with an integrand being proportional to z-component of high-frequency magnetic field. The x- and y-component of this momentum are equal in value but opposite in sign. The obtained result is compared with Panofsky-Wenzel theorem. This result gives one more procedure to check the accuracy of high-frequency focusing simulation.
Illustrations of the Relativistic Conservation Law for the Center of Energy
Boyer, T H
2005-01-01
The relativistic conservation law involving the center of energy is reviewed and illustrated using simple examples from classical electromagnetic theory. It is emphasized that this conservation law is parallel to the conservation laws for energy, linear momentum, and energy, in arising from the generators of the Poincare group for electromagnetic theory; yet this relativistic law reflecting the continuous flow of energy goes virtually unmentioned in the text books. The illustrations here present situations both where external forces are present and are absent. The cases of a parallel plate capacitor, a flattened slip-joint solenoid, and two interacting charges are included.
Relativistic Treatment of Spinless Particles Subject to a q-Deformed Morse Potential
Sami Ortakaya
2013-01-01
The approximate analytical solutions of the Klein-Gordon equation with equal scalar and vector q-deformed Morse potential are presented for arbitrary (l)-states by using Laplace integral transform.The energy eigenvalues and corresponding wave functions are obtained for n and (l) values.In this study,in the non-relativistic limit c → ∞,it has been also provided that the energy eigenfunctions for Klein-Gordon system turn into those for Schr(o)dinger one.
Energy-momentum balance in particle - domain wall perforating collision
Gal'tsov, D V; Spiirin, P A
2014-01-01
We investigate the energy-momentum balance in the perforating collision of a point particle with an infinitely thin planar domain wall within the linearized gravity in arbitrary dimensions. Since the metric of the wall increases with distance, the wall and the particle are never free, and their energy-momentum balance involves not only the instantaneous kinetic momenta, but also the non-local contribution of gravitational stresses. However, careful analysis shows that the stresses can be unambiguously divided between the colliding objects leading to definition of the gravitationally dressed momenta. These take into account for gravity in the same way as the potential energy does in the non-relativistic theory, but our treatment is fully relativistic. Another unusual feature of our problem is the non-vanishing flux of the total energy-momentum tensor through the lateral surface of the world tube. In this case the zero divergence of the energy-momentum tensor does not imply conservation of the total momentum de...
Horwitz, L. P.; Land, Martin C.; Gill, Tepper; Lusanna, Luca; Salucci, Paolo
2013-04-01
Although the subject of relativistic dynamics has been explored, from both classical and quantum mechanical points of view, since the work of Einstein and Dirac, its most striking development has been in the framework of quantum field theory. The very accurate calculations of spectral and scattering properties, for example, of the anomalous magnetic moment of the electron and the Lamb shift in quantum electrodynamics, and many qualitative features of the strong and electroweak interactions, demonstrate the very great power of description achieved in this framework. Yet, many fundamental questions remain to be clarified, such as the structure of classical relativistic dynamical theories on the level of Hamilton and Lagrange in Minkowski space as well as on the curved manifolds of general relativity. There moreover remains the important question of the covariant classical description of systems at high energy for which particle production effects are not large, such as discussed in Synge's book, The Relativistic Gas, and in Balescu's book on relativistic statistical mechanics. In recent years, the study of high energy plasmas and heavy ion collisions has emphasized the importance of developing the techniques of relativistic mechanics. The results of Lindner et al [Physical Review Letters 95 0040401 (2005)] as well as the more recent proposal of Palacios et al [Phys. Rev. Lett. 103 253001 (2009)] and others, have shown that there must be a quantum theory with coherence in time. Such a theory, manifestly covariant under the transformations of special relativity with an invariant evolution parameter, such as that of Stueckelberg [Helv. Phys. Acta 14 322, 588 (1941); 15 23 (1942); see also R P Feynman Phys. Rev. 80 4401 and J S Schwinger Phys. Rev. 82 664 (1951)] could provide a suitable basis for the study of such questions, as well as many others for which the application of the standard methods of quantum field theory are difficult to manage, involving, in particular
High energy neutrino and gamma ray transients from relativistic supernova shock breakouts
Kashiyama, Kazumi; Horiuchi, Shunsaku; Gao, Shan; Mészáros, Peter
2013-01-01
Relativistic shocks that accompany supernovae (SNe) produce X-ray burst emissions as they break out in the dense circumstellar medium around the progenitors. This phenomenon is sometimes associated with peculiar low-luminosity gamma-ray bursts (LL GRBs). Here, we investigate the high energy neutrino and gamma-ray counterparts of such a class of SNe. Just beyond the shock breakout radius, particle acceleration in the collisionless shock starts to operate in the presence of breakout photons. We show that protons may be accelerated to sufficiently high energies and produce high energy neutrinos and gamma rays via the photomeson interaction. These neutrinos and gamma rays may be detectable from 10 Mpc away by IceCube/KM3Net as multi-TeV transients almost simultaneously with the X-ray burst emission, and even from 100 Mpc away with follow-up observations by CTA using a wide-field sky monitor like Swift as a trigger. A statistical technique using a stacking approach could also be possible for the detection, with th...
Dubus, Guillaume; Fromang, Sébastien
2015-01-01
Detailed modeling of the high-energy emission from gamma-ray binaries has been propounded as a path to pulsar wind physics. Fulfilling this ambition requires a coherent model of the flow and its emission in the region where the pulsar wind interacts with the stellar wind of its companion. We developed a code that follows the evolution and emission of electrons in the shocked pulsar wind based on inputs from a relativistic hydrodynamical simulation. The code is used to model the well-documented spectral energy distribution and orbital modulations from LS 5039. The pulsar wind is fully confined by a bow shock and a back shock. The particles are distributed into a narrow Maxwellian, emitting mostly GeV photons, and a power law radiating very efficiently over a broad energy range from X-rays to TeV gamma rays. Most of the emission arises from the apex of the bow shock. Doppler boosting shapes the X-ray and VHE lightcurves, constraining the system inclination to $i\\approx 35^{\\rm o}$. There is a tension between th...
Chen, Zaigao; Wang, Jianguo; Wang, Yue; Qiao, Hailiang; Zhang, Dianhui; Guo, Weijie
2013-11-01
Optimal design method of high-power microwave source using particle simulation and parallel genetic algorithms is presented in this paper. The output power, simulated by the fully electromagnetic particle simulation code UNIPIC, of the high-power microwave device is given as the fitness function, and the float-encoding genetic algorithms are used to optimize the high-power microwave devices. Using this method, we encode the heights of non-uniform slow wave structure in the relativistic backward wave oscillators (RBWO), and optimize the parameters on massively parallel processors. Simulation results demonstrate that we can obtain the optimal parameters of non-uniform slow wave structure in the RBWO, and the output microwave power enhances 52.6% after the device is optimized.
A particle-hole calculation for pion production in relativistic heavy-ion collisions
Norbury, J. W.; Deutchman, P. A.; Townsend, L. W.
1985-01-01
A differential cross section for pi-meson production in peripheral heavy-ion collisions is formulated within the context of a particle-hole model in the Tamm-Dancoff approximation. This is the first attempt at a fully quantum-mechanical particle-hole calculation for pion production in relativistic heavy-ion collisions. The particular reaction studied is an O-16 projectile colliding with a C-12 target at rest. In the projectile a linear combination of isobar-hole states is formed, with the possibility of a coherent isobar giant resonance. The target can be excited to its giant M1 resonance (J-pi = 1(+), T = 1) at 15.11 MeV, or to its isobar analog neighbors, B-12 at 13.4 MeV and N-12 at 17.5 MeV. The theory is compared to recent experimental results.
Radiation from Particles Accelerated in Relativistic Jet Shocks and Shear-flows
Nishikawa, K -I; Dutan, I; Zhang, B; Meli, A; Choi, E J; Min, K; Niemiec, J; Mizuno, Y; Medvedev, M; Nordlund, A; Frederiksen, J T; Sol, H; Pohl, M; Hartmann, D
2014-01-01
We have investigated particle acceleration and emission from shocks and shear flows associated with an unmagnetized relativistic jet plasma propagating into an unmagnetized ambient plasma. Strong electro-magnetic fields are generated in the jet shock via the filamentation (Weibel) instability. Shock field strength and structure depend on plasma composition (($e^{\\pm}$ or $e^-$- $p^+$ plasmas) and Lorentz factor. In the velocity shear between jet and ambient plasmas, strong AC ($e^{\\pm}$ plasmas) or DC ($e^-$- $p^+$ plasmas) magnetic fields are generated via the kinetic Kelvin-Helmholtz instability (kKHI), and the magnetic field structure also depends on the jet Lorentz factor. We have calculated, self-consistently, the radiation from electrons accelerated in shock generated magnetic fields. The spectra depend on the jet's initial Lorentz factor and temperature via the resulting particle acceleration and magnetic field generation. Our ongoing "Global" jet simulations containing shocks and velocity shears will ...
Shukla, Chandrasekhar; Das, Amita; Patel, Kartik
2016-08-01
We carry out particle-in-cell simulations to study the instabilities associated with a 2-D sheared electron flow configuration against a neutralizing background of ions. Both weak and strong relativistic flow velocities are considered. In the weakly relativistic case, we observe the development of electromagnetic Kelvin-Helmholtz instability with similar characteristics as that predicted by the electron Magnetohydrodynamic (EMHD) model. On the contrary, in a strong relativistic case, the compressibility effects of electron fluid dominate and introduce upper hybrid electrostatic oscillations transverse to the flow which are very distinct from EMHD fluid behavior. In the nonlinear regime, both weak and strong relativistic cases lead to turbulence with broad power law spectrum.
On the Question of Interference in Radiation Produced by Relativistic Channeled Particles
Boldyshev, V F
2002-01-01
Two approaches used in the description of the channeling radiation emitted from relativistic positrons are compared with each other. In the first (traditional) case, the probability of the process is proportional to a sum of absolute squares of the amplitudes of the transition between two states with definite transverse energy levels of the positrons traversing single crystals. In the second case, we begin with calculation of the sum of amplitudes for transition between states with different transverse energy levels for corresponding radiation frequency, and then the sum is squared. One must keep in mind that the latter approach can be used only in the case when positrons move in a nearly harmonic planar potential with equidistant transverse energy levels. It is shown that the calculation based on the second approach can give rise to a peak structure in the spectrum when the number of transverse energy levels is much greater than one.
Bai, Xue-Ning; Sironi, Lorenzo; Spitkovsky, Anatoly
2014-01-01
We formulate a magnetohydrodynamic-particle-in-cell (MHD-PIC) method for describing the interaction between collisionless cosmic ray (CR) particles and a thermal plasma. The thermal plasma is treated as a fluid, obeying equations of ideal MHD, while CRs are treated as relativistic Lagrangian particles subject to the Lorentz force. Backreaction from CRs to the gas is included in the form of momentum and energy feedback. In addition, we include the electromagnetic feedback due to CR-induced Hall effect that becomes important when the electron-ion drift velocity of the background plasma induced by CRs approaches the Alfv\\'en velocity. Our method is applicable on scales much larger than the ion inertial length, bypassing the microscopic scales that must be resolved in conventional PIC methods, while retaining the full kinetic nature of the CRs. We have implemented and tested this method in the Athena MHD code, where the overall scheme is second-order accurate and fully conservative. As a first application, we des...
Augusto, Carlos; Navia, Carlos; de Oliveira, Marcel N.; Fauth, Anderson; Nepomuceno, André
2016-02-01
Active region NOAA AR2036, located at S20W34 at the Sun disk, produced a moderately strong (GOES class M7.3) flare on 2014 April 18. The flare itself was long in duration, and a halo coronal mass ejection (CME) was emitted. In addition, a radiation storm, that is, solar energetic particles (SEP), began to reach the Earth at 13:30 UT in the aftermath of the solar blast, meeting the condition of an S1 (minor) radiation storm level. In temporal coincidence with the onset of the S1 radiation storm, the Tupi telescopes located within the South Atlantic Anomaly (SAA) detected a fast rise in the muon counting rate, caused by relativistic protons from this solar blast, with a confidence of up to 3.5% at peak. At the time of the solar blast, of all ground-based detectors, the Tupi telescopes had the best geoeffective location. Indeed, in association with the radiation storm, a gradual increase in the particle intensity was found in some neutron monitors (NMs), all of them in the west region relative to the Sun-Earth line, yet within the geoeffective region. However, their confidence levels are smaller: up to 3%. The fast rising observed at Tupi suggests possible detection of solar particles emitted during the impulsive phase, following by a gradual phase observed also at NMs. Details of these observations, including the expected energy spectrum, are reported.
Bliokh, Konstantin Y
2011-01-01
We consider the relativistic deformation of quantum waves and mechanical bodies carrying intrinsic angular momentum (AM). When observed in a moving reference frame, the centroid of the object undergoes an AM-dependent transverse shift. This is the relativistic analogue of the spin Hall effect, which occurs in free space without any external fields. Remarkably, the shifts of the geometric and energy centroids differ by a factor of 2, and both centroids are crucial for the correct Lorentz transformations of the AM tensor. We examine manifestations of the relativistic Hall effect in quantum vortices, mechanical flywheel, and discuss various fundamental aspects of the phenomenon. The perfect agreement of quantum and relativistic approaches allows applications at strikingly different scales: from elementary spinning particles, through classical light, to rotating black-holes.
Wachter, H
2007-01-01
This is the second part of a paper about a q-deformed analog of non-relativistic Schroedinger theory. It applies the general ideas of part I and tries to give a description of one-particle states on q-deformed quantum spaces like the braided line or the q-deformed Euclidean space in three dimensions. Hamiltonian operators for the free q-deformed particle in one as well as three dimensions are introduced. Plane waves as solutions to the corresponding Schroedinger equations are considered. Their completeness and orthonormality relations are written down. Expectation values of position and momentum observables are taken with respect to one-particle states and their time-dependence is discussed. A potential is added to the free-particle Hamiltonians and q-analogs of the Ehrenfest theorem are derived from the Heisenberg equations of motion. The conservation of probability is proved.
Velocity operator and velocity field for spinning particles in (non-relativistic) quantum mechanics
Recami, E. [Bergamo Univ. (Italy). Facolta` di Ingegneria]|[INFN, Milan (Italy)]|[Campinas State Univ., SP (Brazil). Dept. of Applied Math.; Salesi, G. [Catania Univ. (Italy). Dip. di Fisica
1995-06-01
Starting from the formal expressions of the hydrodynamical (or local) quantities employed in the applications of Clifford Algebras to quantum mechanics, the paper introduces - in terms of the ordinary tensorial framework - a new definition for the field of a generic quantity. By translating from Clifford into tensor algebra, a new (non-relativistic) velocity operator for a spin 1/2 particle is also proposed. This operator is the sum of the ordinary part p/m describing the mean motion (the motion of the center-of-mass), and of a second part associated with the so-called Zitterbewegung, which is the spin internal motion observed in the center-of- mass frame. This spin component of the velocity operator is non-zero not only in the Pauli theoretical framework, i.e. in presence of external magnetic fields and spin precession, but also in the Schroedinger case, when the wave-function is a spin eigenstate. In the latter case, one gets a decomposition of the velocity field for the Madelueng fluid into two distinct parts: which the constitutes the non-relativistic analogue of the Gordon decomposition for the Dirac current.
A relativistic correction to semiclassical charmonium
Weiss, J.
1995-09-01
It is shown that the relativistic linear potentials, introduced by the author within the particle à la Wheeler-Feynman direct-interaction (AAD) theory, applied to the semiclassically quantized charmonium, yield energy spectrum comparable to that of some known models. Using the expansion of the relativistic linear AAD potentials in powers ofc -1, the charmonium spectrum, given as a rule by Bohr-Sommerfeld quantization of circular orbits, is extended up to the second order of relativistic corrections.
Relativistic particles with rigidity generating non-standard examples of Willmore-Chen hypersurfaces
Arroyo, Josu; Garay, Oscar J. [Departamento de Matematicas, Universidad del Pais Vasco, Bilbao (Spain)]. E-mails: mtparolj@lg.ehu.es; mtpgabeo@lg.ehu.es; Barros, Manuel [Departamento de Geometria y Topologia, Universidad de Granada, Granada (Spain)]. E-mail: mbarros@ugr.es
2002-08-16
We study a natural extension to higher dimensions of the Nambu-Goto-Polyakov action. In particular, those dynamical objects evolving with SO(3) symmetry in four dimensions. We show that this problem is strongly related to that of relativistic particles with rigidity of order three in a hyperbolic plane. The moduli space of solitonic solutions is completely determined in terms of the so-called rotation number. A quantization principle for closed solutions is also obtained and this gives a rational one-parameter family of Willmore-Chen hypersurfaces in the standard conformal structure of dimension four. Moreover, these are the first non-standard examples of this kind of hypersurfaces. (author)
Dieckmann, M. E.; Sarri, G.; Markoff, S.; Borghesi, M.; Zepf, M.
2015-05-01
Context. The jets of compact accreting objects are composed of electrons and a mixture of positrons and ions. These outflows impinge on the interstellar or intergalactic medium and both plasmas interact via collisionless processes. Filamentation (beam-Weibel) instabilities give rise to the growth of strong electromagnetic fields. These fields thermalize the interpenetrating plasmas. Aims: Hitherto, the effects imposed by a spatial non-uniformity on filamentation instabilities have remained unexplored. We examine the interaction between spatially uniform background electrons and a minuscule cloud of electrons and positrons. The cloud size is comparable to that created in recent laboratory experiments and such clouds may exist close to internal and external shocks of leptonic jets. The purpose of our study is to determine the prevalent instabilities, their ability to generate electromagnetic fields and the mechanism, by which the lepton micro-cloud transfers energy to the background plasma. Methods: A square micro-cloud of equally dense electrons and positrons impinges in our particle-in-cell (PIC) simulation on a spatially uniform plasma at rest. The latter consists of electrons with a temperature of 1 keV and immobile ions. The initially charge- and current neutral micro-cloud has a temperature of 100 keV and a side length of 2.5 plasma skin depths of the micro-cloud. The side length is given in the reference frame of the background plasma. The mean speed of the micro-cloud corresponds to a relativistic factor of 15, which is relevant for laboratory experiments and for relativistic astrophysical outflows. The spatial distributions of the leptons and of the electromagnetic fields are examined at several times. Results: A filamentation instability develops between the magnetic field carried by the micro-cloud and the background electrons. The electromagnetic fields, which grow from noise levels, redistribute the electrons and positrons within the cloud, which boosts
Belich, H
2015-01-01
The behaviour of a relativistic scalar particle subject to a scalar potential under the effects of the violation of the Lorentz symmetry in the cosmic string spacetime is discussed. It is considered two possible scenarios of the Lorentz symmetry breaking in the CPT-even gauge sector of the Standard Model Extension defined by a tensor $\\left(K_{F}\\right)_{\\mu\
Relativistic and Radiative Energy Shifts for Rydberg States
Jentschura, U D; Evers, J; Mohr, P J; Keitel, C H
2004-01-01
We investigate relativistic and quantum electrodynamic effects for highly-excited bound states in hydrogenlike systems (Rydberg states). In particular, hydrogenic one-loop Bethe logarithms are calculated for all circular states (l = n-1) in the range 20 20 to an accuracy of five to seven decimal digits, within the specified manifolds of atomic states. Within the numerical accuracy, the results constitute unified, general formulas for quantum electrodynamic corrections whose validity is not restricted to a single atomic state. The results are relevant for accurate predictions of radiative shifts of Rydberg states and for the description of the recently investigated laser-dressed Lamb shift, which is observable in a strong coherent-wave light field.
Perturbative results for two and three particle threshold energies in finite volume
Hansen, Maxwell T
2016-01-01
We calculate the energy of the state closest to threshold for two and three identical, spinless particles confined to a cubic spatial volume with periodic boundary conditions and with zero total momentum in the finite-volume frame. The calculation is performed in relativistic quantum field theory with particles coupled via a $\\lambda \\phi^4$ interaction, and we work through order $\\lambda^3$. The energy shifts begin at ${\\cal O}(1/L^3)$, and we keep subleading terms proportional to $1/L^4$, $1/L^5$ and $1/L^6$. These terms allow a non-trivial check of the results obtained from quantization conditions that hold for arbitrary interactions, namely that of L\\"uscher for two particles and our recently developed formalism for three particles. We also compare to previously obtained results based on non-relativistic quantum mechanics.
Doornenbal, P., E-mail: pieter@ribf.riken.j [Institut fuer Kernphysik, Universitaet zu Koeln, 50937 Koeln (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Reiter, P. [Institut fuer Kernphysik, Universitaet zu Koeln, 50937 Koeln (Germany); Grawe, H.; Saito, T. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Al-Khatib, A. [Helmholtz-Institut fuer Strahlen- und Kernphysik, Universitaet Bonn, 53115 Bonn (Germany); Banu, A.; Beck, T.; Becker, F. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Bednarczyk, P. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); The Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, 31-342 Krakow (Poland); Benzoni, G. [INFN Sezione di Milano, 20133 Milano (Italy); Bracco, A. [INFN Sezione di Milano, 20133 Milano (Italy); Dipartimento di Fisica, Universita di Milano, 20133 Milano (Italy); Buerger, A. [Helmholtz-Institut fuer Strahlen- und Kernphysik, Universitaet Bonn, 53115 Bonn (Germany); Caceres, L. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Departamento de Fisica Teorica, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Camera, F. [INFN Sezione di Milano, 20133 Milano (Italy); Dipartimento di Fisica, Universita di Milano, 20133 Milano (Italy); Chmel, S. [Helmholtz-Institut fuer Strahlen- und Kernphysik, Universitaet Bonn, 53115 Bonn (Germany); Crespi, F.C.L. [INFN Sezione di Milano, 20133 Milano (Italy); Dipartimento di Fisica, Universita di Milano, 20133 Milano (Italy); Geissel, H.; Gerl, J.; Gorska, M. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Grebosz, J. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, 31-342 Krakow (Poland)
2010-02-01
The lineshapes and peak position of Doppler corrected gamma-ray spectra from in-beam experiments at relativistic energies are investigated with respect to the intrinsic energy resolution of the employed detectors, the particles' velocities, and the photons' emission angle uncertainties at the moment of gamma-ray emission. The uncertainties in velocity and photon emission angle are dependent on the lifetime of the excited state. The impact of these two observables on the lineshape and energy resolution are studied for the RISING gamma-spectrometer by means of simulations and experimental results from a two-step fragmentation experiment at approx200MeV/u. Potential use of the distinct lineshape for lifetime determination is demonstrated for measured gamma-ray transitions.
On The Relativistic Classical Motion of a Radiating Spinning Particle in a Magnetic Field
Kar, Arnab
2010-01-01
We propose classical equations of motion for a charged particle with magnetic moment, taking radiation reaction into account. This generalizes the Landau-Lifshitz equations for the spinless case. In the special case of spin-polarized motion in a constant magnetic field (synchrotron motion) we verify that the particle does lose energy. Previous proposals did not predict dissipation of energy and also suffered from runaway solutions analogous to those of the Lorentz-Dirac equations of motion.
On the relativistic classical motion of a radiating spinning particle in a magnetic field
Kar, Arnab; Rajeev, S. G.
2011-04-01
We propose classical equations of motion for a charged particle with magnetic moment, taking radiation reaction into account. This generalizes the Landau-Lifshitz equations for the spinless case. In the special case of spin-polarized motion in a constant magnetic field (synchrotron motion) we verify that the particle does lose energy. Previous proposals did not predict dissipation of energy and also suffered from runaway solutions analogous to those of the Lorentz-Dirac equations of motion.
On pseudosupersymmetric oscillators and reality of relativistic energies for vector mesons
Beckers, Jules; Debergh, Nathalie
1995-01-01
Specific oscillators - hereafter called pseudosupersymmetric oscillators - appear as interesting nonrelativistic concepts in connection with the study of relativistic vector mesons interacting with an external constant magnetic field when the real character of the energy eigenvalues is required as expected. A new pseudosupersymmetric quantum mechanics can then be developed and the corresponding pseudosupersymmetries can be pointed out.
Particle Production In Relativistic Heavy-ion Collisions With Perturbative Qcd
Zhang, Y
2003-01-01
The commissioning of the Relativistic Heavy Ion Collider (RHIC) opened new era in nuclear collision physics, with the study of excited strongly-interacting matter becoming a reality. A primary motivation for studying high-p T hadron production in ultrarelativistic heavy ion collisions is to gain insight into the gluon density of the quark-gluon medium via jet energy loss. The sensitivity of high-pT hadron spectra to initial gluon density may be a probe of the formation of quark-gluon-plasma (QGP). However, a thorough understanding of ultrarelativistic nuclear (AA ) collisions requires the accurate description of proton-proton ( pp) and proton-nucleus (pA) collisions in the same framework. In the present dissertation we follow the evolution of high-p T hadron production in relativistic collisions from pp to pA to AA reactions. The perturbative Quantum Chromodynamics (pQCD) improved parton model is used for the study. We apply leading- order (LO) pQCD throughout, and augment the standard one- dimensional cross ...
Spectrum and Composition of Ultra-high Energy Cosmic Rays from Semi-relativistic Hypernovae
Liu, Ruo-Yu
2011-01-01
It has been suggested that hypernova remnants, with a substantial amount of energy in semi-relativistic ejecta, can accelerate intermediate mass or heavy nuclei to ultra-high energies and provide sufficient amount of energy in cosmic rays to account for the observed flux. We here calculate the expected energy spectrum and chemical composition of ultra-high energy cosmic rays from such semi-relativistic hypernovae. With a chemical composition equal to that of the hypernova ejecta and a flat or hard spectrum for cosmic rays at the sources, the spectrum and composition of the propagated cosmic rays observed at the Earth can be compatible with the measurements by the Pierre Auger Observatory.
Relativistic contributions to single and double core electron ionization energies of noble gases.
Niskanen, J; Norman, P; Aksela, H; Agren, H
2011-08-07
We have performed relativistic calculations of single and double core 1s hole states of the noble gas atoms in order to explore the relativistic corrections and their additivity to the ionization potentials. Our study unravels the interplay of progression of relaxation, dominating in the single and double ionization potentials of the light elements, versus relativistic one-electron effects and quantum electrodynamic effects, which dominate toward the heavy end. The degree of direct relative additivity of the relativistic corrections for the single electron ionization potentials to the double electron ionization potentials is found to gradually improve toward the heavy elements. The Dirac-Coulomb Hamiltonian is found to predict a scaling ratio of ∼4 for the relaxation induced relativistic energies between double and single ionization. Z-scaling of the computed quantities were obtained by fitting to power law. The effects of nuclear size and form were also investigated and found to be small. The results indicate that accurate predictions of double core hole ionization potentials can now be made for elements across the full periodic table.
Kholmetskii, Alexander; Missevitch, Oleg; Yarman, Tolga
2016-02-01
We address to the Poynting theorem for the bound (velocity-dependent) electromagnetic field, and demonstrate that the standard expressions for the electromagnetic energy flux and related field momentum, in general, come into the contradiction with the relativistic transformation of four-vector of total energy-momentum. We show that this inconsistency stems from the incorrect application of Poynting theorem to a system of discrete point-like charges, when the terms of self-interaction in the product {\\varvec{j}} \\cdot {\\varvec{E}} (where the current density {\\varvec{j}} and bound electric field {\\varvec{E}} are generated by the same source charge) are exogenously omitted. Implementing a transformation of the Poynting theorem to the form, where the terms of self-interaction are eliminated via Maxwell equations and vector calculus in a mathematically rigorous way (Kholmetskii et al., Phys Scr 83:055406, 2011), we obtained a novel expression for field momentum, which is fully compatible with the Lorentz transformation for total energy-momentum. The results obtained are discussed along with the novel expression for the electromagnetic energy-momentum tensor.
Mueller, Bernhard
2009-05-07
In this thesis, we have presented the first multi-dimensional models of core-collapse supernovae that combine a detailed, up-to-date treatment of neutrino transport, the equation of state, and - in particular - general relativistic gravity. Building on the well-tested neutrino transport code VERTEX and the GR hydrodynamics code CoCoNuT, we developed and implemented a relativistic generalization of a ray-by-ray-plus method for energy-dependent neutrino transport. The result of these effort, the VERTEX-CoCoNuT code, also incorporates a number of improved numerical techniques that have not been used in the code components VERTEX and CoCoNuT before. In order to validate the VERTEX-CoCoNuT code, we conducted several test simulations in spherical symmetry, most notably a comparison with the one-dimensional relativistic supernova code AGILE-BOLTZTRAN and the Newtonian PROMETHEUSVERTEX code. (orig.)
Lienert, Matthias, E-mail: lienert@math.lmu.de [Mathematisches Institut, Ludwig-Maximilians-Universität, Theresienstr. 39, 80333 München (Germany)
2015-04-15
The question how to Lorentz transform an N-particle wave function naturally leads to the concept of a so-called multi-time wave function, i.e., a map from (space-time){sup N} to a spin space. This concept was originally proposed by Dirac as the basis of relativistic quantum mechanics. In such a view, interaction potentials are mathematically inconsistent. This fact motivates the search for new mechanisms for relativistic interactions. In this paper, we explore the idea that relativistic interaction can be described by boundary conditions on the set of coincidence points of two particles in space-time. This extends ideas from zero-range physics to a relativistic setting. We illustrate the idea at the simplest model which still possesses essential physical properties like Lorentz invariance and a positive definite density: two-time equations for massless Dirac particles in 1 + 1 dimensions. In order to deal with a spatio-temporally non-trivial domain, a necessity in the multi-time picture, we develop a new method to prove existence and uniqueness of classical solutions: a generalized version of the method of characteristics. Both mathematical and physical considerations are combined to precisely formulate and answer the questions of probability conservation, Lorentz invariance, interaction, and antisymmetry.
Itoh, Y
2004-01-01
An equation of motion for relativistic compact binaries is derived through the third post-Newtonian (3 PN) approximation of general relativity. The strong field point particle limit and multipole expansion of the stars are used to solve iteratively the harmonically relaxed Einstein equations. We take into account the Lorentz contraction on the multipole moments defined in our previous works. We then derive a 3 PN acceleration of the binary orbital motion of the two spherical compact stars based on a surface integral approach which is a direct consequence of local energy momentum conservation. Our resulting equation of motion admits a conserved energy (neglecting the 2.5 PN radiation reaction effect), is Lorentz invariant and is unambiguous: there exist no undetermined parameter reported in the previous works. We shall show that our 3 PN equation of motion agrees physically with the Blanchet and Faye 3 PN equation of motion if $\\lambda = - 1987/3080$, where $\\lambda$ is the parameter which is undetermined with...
Inoue, Yoshiyuki
2016-01-01
Relativistic jets launched by SMBHs are the most energetic particle accelerators in the universe. However, the baryon mass loading efficiency onto the jets from the accretion and the particle acceleration efficiency in the jets have been veiled in mystery. With the latest data sets, we perform multi-wavelength spectral analysis of quiescent spectra of 13 TeV gamma-ray detected HBLs following one-zone synchrotron-self-Compton (SSC) model. We determine the minimum, cooling break, and maximum electron Lorentz factors following the diffusive shock acceleration (DSA) theory. We find that HBLs have $P_B/P_e\\sim0.025$ where $P_B$ and $P_e$ is the Poynting and electron power, respectively. The radiative efficiency of the jets is found to be $P_{\\rm rad}/P_{\\rm jet}\\sim0.026$. $P_{\\rm rad}$ and $P_{\\rm jet}$ is the radiative and total jet power, respectively. We find that the jet power relates to the black hole mass as $P_{\\rm jet}/L_{\\rm Edd}\\sim0.036$. We further find that HBLs have the mass loading efficiency of $\\...
Extra relativistic degrees of freedom without extra particles using Planck data
Mastache, Jorge
2013-01-01
A recent number of analysis of cosmological data have shown indications for the presence of extra radiation beyond the standard model at equality and nucleosynthesis epoch, which has been usually interpreted as an effective number of neutrinos, Neff > 3.046. In this work we establish the theoretical basis for a particle physics-motivated model (Bound Dark Matter, BDM) which explain the need of extra radiation. The BDM model describes dark matter particles which are relativistic at a scale below aac due to non-perturbative methods, as protons and neutrons do, this process is described by a time dependent equation of state, w_bdm(a). We compute the range of values of the BDM model, xc=ac*vc, that explain the values obtain for the 4He at BBN and Neff at equality. Combining different analysis we conclude that this may happen in xc = 5.01 (^{+6.01}_{-5.01}) x 10^{-5} with a vc = 0.56 \\pm 0.39. We conclude that we can account for the apparent extra radiation Nex using phase transition in the dark matter with a time...
高梁; 钱宝良; 葛行军; 王运行
2011-01-01
A moderate-energy P-band relativistic backward wave oscillator (RBWO) is proposed and investigated by using the 2. 5D fully electromagnetic particle-in-cell code, KARAT. A double corrugated configuration is designed in the coaxial slow wave structure (SWS) of the moderate-energy P-band RBWO, and thus enlarges the temporal growth rate and the beam-wave interaction space of the RBWO, resulting in larger power capacity and shorter microwave output saturation time. The presented P-band RBWO has an increase of about two times compared with the conventional one in the radial range of the beam-wave interaction space, with almost the same period of SWS. The simulation results show that a microwave with the power of 267 MW, frequency of 867 MHz and efficiency of 30% is obtained with the diode voltage, diode current and guiding magnetic field of 300 kV, 3. 0 kA and 1.0T, respectively.%提出了一种新型的中等能量P波段相对论返波振荡器,该器件将慢波结构由低波段普遍采用的同轴外波纹结构变为同轴双波纹结构,使得径向束-波作用空间扩大了2倍,一定程度上增加了器件的功率容量；另外同轴双波纹结构还较大提高了器件的时间增长率,从而有效地减小了微波输出饱和时间.经优化设计,该结构在二极管电压300 kV、电流3 kA、导引磁场1.0T的情况下,获得267 MW的微波输出,效率达30％,频率为867 MHz.
Pramanik, Souvik; Ghosh, Subir
2013-10-01
We have developed a unified scheme for studying noncommutative algebras based on generalized uncertainty principle (GUP) and Snyder form in a relativistically covariant point particle Lagrangian (or symplectic) framework. Even though the GUP-based algebra and Snyder algebra are very distinct, the more involved latter algebra emerges from an approximation of the Lagrangian model of the former algebra. Deformed Poincaré generators for the systems that keep space-time symmetries of the relativistic particle models have been studied thoroughly. From a purely constrained dynamical analysis perspective the models studied here are very rich and provide insights on how to consistently construct approximate models from the exact ones when nonlinear constraints are present in the system. We also study dynamics of the GUP particle in presence of external electromagnetic field.
Anisotropy of low energy direct photons in relativistic heavy ion collisions
Koide, T.; Kodama, T.
2016-09-01
Using the Wigner function approach for electromagnetic radiation fields, we investigate the behavior of low energy photons radiated by the deceleration processes of two colliding nuclei in relativistic heavy ion collisions. The angular distribution reveals information of the initial geometric configurations, which is reflected in the anisotropic parameter v 2, with an increasing v 2 as energy decreases. This behavior is qualitatively different to the v 2 from the hadrons produced in the collisions.
Anisotropicity of Low Energy Direct Photons in Relativistic Heavy Ion Collisions
Koide, T
2016-01-01
We investigate the behavior of low energy photons radiated by deceleration processes of two colliding nuclei in relativistic heavy ion collisions, where their angular distribution reveals information of the initial geometric configurations. Such a property is reflected in the anisotropic parameter v_{2}, showing an increasing v_{2} as energy decreases, which is qualitatively different behavior from v_{2} from hadrons produced in the collisions.
Adamczyk, L; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Bai, X; Bairathi, V; Banerjee, A; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Bouchet, J; Brandenburg, D; Brandin, A V; Bunzarov, I; Butterworth, J; Caines, H; Calder{ó}n~de~la~Barca~S{á}nchez, M; Campbell, J M; Cebra, D; Cervantes, M C; Chakaberia, I; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, J H; Chen, X; Cheng, J; Cherney, M; Chisman, O; Christie, W; Contin, G; Crawford, H J; Das, S; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; di Ruzza, B; Didenko, L; Dilks, C; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Eppley, G; Esha, R; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Federic, P; Fedorisin, J; Feng, Z; Filip, P; Fisyak, Y; Flores, C E; Fulek, L; Gagliardi, C A; Garand, D; Geurts, F; Gibson, A; Girard, M; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Hamad, A; Hamed, A; Haque, R; Harris, J W; He, L; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, H Z; Huang, B; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Jia, J; Jiang, K; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Khan, Z H; Kikoła, D P; Kisel, I; Kisiel, A; Kochenda, L; Koetke, D D; Kollegger, T; Kosarzewski, L K; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; Li, X; Li, W; Li, C; Li, Z M; Li, Y; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, R; Ma, L; Ma, Y G; Magdy, N; Majka, R; Manion, A; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; Meehan, K; Minaev, N G; Mioduszewski, S; Mishra, D; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Okorokov, V; Olvitt, D; Page, B S; Pak, R; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlik, B; Pei, H; Perkins, C; Peterson, A; Pile, P; Planinic, M; Pluta, J; Poljak, N; Poniatowska, K; Porter, J; Posik, M; Poskanzer, A M; Pruthi, N K; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Salur, S; Sandweiss, J; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Sharma, M K; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Sikora, R; Simko, M; Singha, S; Skoby, M J; Smirnov, N; Smirnov, D; Song, L; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stepanov, M; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Summa, B; Sun, X; Sun, Z; Sun, X M; Sun, Y; Surrow, B; Svirida, N; Szelezniak, M A; Tang, Z; Tang, A H; Tarnowsky, T; Tawfik, A; Thaeder, J; Thomas, J H; Timmins, A R; Tlusty, D; Todoroki, T; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Tripathy, S K; Trzeciak, B A; Tsai, O D; Ullrich, T; Underwood, D G; Upsal, I; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Varma, R; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Vossen, A; Wang, F; Wang, J S; Wang, Y; Wang, G; Wang, H; Webb, J C; Webb, G; Wen, L; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu,; Wu, Y F; Xiao, Z G; Xie, W; Xin, K; Xu, N; Xu, Q H; Xu, Z; Xu, Y F; Xu, H; Yang, C; Yang, Y; Yang, S; Yang, Q; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I -K; Yu, N; Zbroszczyk, H; Zha, W; Zhang, X P; Zhang, Z; Zhang, S; Zhang, J; Zhang, Y; Zhang, J B; Zhao, J; Zhong, C; Zhou, L; Zhu, X; Zoulkarneeva, Y; Zyzak, M
2016-01-01
Elliptic flow (v_{2}) values for identified particles at midrapidity in Au + Au collisions measured by the STAR experiment in the Beam Energy Scan at the Relativistic Heavy Ion Collider at sqrt{s_{NN}}= 7.7-62.4 GeV are presented for three centrality classes. The centrality dependence and the data at sqrt{s_{NN}}= 14.5 GeV are new. Except at the lowest beam energies we observe a similar relative v_{2} baryon-meson splitting for all centrality classes which is in agreement within 15% with the number-of-constituent quark scaling. The larger v_{2} for most particles relative to antiparticles, already observed for minimum bias collisions, shows a clear centrality dependence, with the largest difference for the most central collisions. Also, the results are compared with AMPT calculations and fit with a Blast Wave model.
Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Bai, X.; Bairathi, V.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Cheng, J.; Cherney, M.; Chisman, O.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, H. Z.; Huang, B.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, Y.; Li, W.; Li, C.; Li, X.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, L.; Ma, Y. G.; Ma, G. L.; Ma, R.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, S.; Raniwala, R.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, X.; Sun, Z.; Sun, Y.; Sun, X. M.; Surrow, B.; Svirida, N.; Szelezniak, M. A.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, F.; Wang, Y.; Wang, G.; Wang, Y.; Wang, J. S.; Wang, H.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, Z.; Xu, H.; Xu, Y. F.; Xu, Q. H.; Xu, N.; Yang, Y.; Yang, C.; Yang, S.; Yang, Y.; Yang, Q.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, Y.; Zhang, S.; Zhang, J.; Zhang, J.; Zhang, Z.; Zhang, X. P.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration
2016-01-01
Elliptic flow (v2) values for identified particles at midrapidity in Au + Au collisions measured by the STAR experiment in the Beam Energy Scan at the Relativistic Heavy Ion Collider at √{sN N}= 7.7 -62.4 GeV are presented for three centrality classes. The centrality dependence and the data at √{sN N}= 14.5 GeV are new. Except at the lowest beam energies, we observe a similar relative v2 baryon-meson splitting for all centrality classes which is in agreement within 15% with the number-of-constituent quark scaling. The larger v2 for most particles relative to antiparticles, already observed for minimum bias collisions, shows a clear centrality dependence, with the largest difference for the most central collisions. Also, the results are compared with a multiphase transport (AMPT) model and fit with a blast wave model.
Relativistic impulse dynamics.
Swanson, Stanley M
2011-08-01
Classical electrodynamics has some annoying rough edges. The self-energy of charges is infinite without a cutoff. The calculation of relativistic trajectories is difficult because of retardation and an average radiation reaction term. By reconceptuallizing electrodynamics in terms of exchanges of impulses rather than describing it by forces and potentials, we eliminate these problems. A fully relativistic theory using photonlike null impulses is developed. Numerical calculations for a two-body, one-impulse-in-transit model are discussed. A simple relationship between center-of-mass scattering angle and angular momentum was found. It reproduces the Rutherford cross section at low velocities and agrees with the leading term of relativistic distinguishable-particle quantum cross sections (Møller, Mott) when the distance of closest approach is larger than the Compton wavelength of the particle. Magnetism emerges as a consequence of viewing retarded and advanced interactions from the vantage point of an instantaneous radius vector. Radiation reaction becomes the local conservation of energy-momentum between the radiating particle and the emitted impulse. A net action is defined that could be used in developing quantum dynamics without potentials. A reinterpretation of Newton's laws extends them to relativistic motion.
Morales Villasevil, A.
1965-07-01
A method is introduced ta deal with relativistic quantum field theory for particles with m=0. Two mappings I and J, giving rise respectively to particle and anti particle states, are defined between a test space and the physical Hilbert space. The intrinsic field operator is then defined as the minimal causal linear combinations of operators belonging to the annihilation-creation algebra associated to the germ and antigerm parts of the element. Local elements are introduced as improper test elements and local field operators are constructed in the same way as the intrinsic ones. Commutation rules are given. (Author) 17 refs.
Horwitz, Lawrence; Hu, Bei-Lok; Lee, Da-Shin; Gill, Tepper; Land, Martin
2011-12-01
Although the subject of relativistic dynamics has been explored from both classical and quantum mechanical points of view since the work of Einstein and Dirac, its most striking development has been in the framework of quantum field theory. The very accurate calculations of spectral and scattering properties, for example, of the anamolous magnetic moment of the electron and the Lamb shift in quantum electrodynamics, and many qualitative features of the strong and electroweak interactions, demonstrate the very great power of description achieved in this framework. Yet, many fundamental questions remain to be clarified, such as the structure of classical realtivistic dynamical theories on the level of Hamilton and Lagrange in Minkowski space as well as on the curved manifolds of general relativity. There moreover remains the important question of the covariant classical description of systems at high energy for which particle production effects are not large, such as discussed in Synge's book, The Relativistic Gas, and in Balescu's book on relativistic statistical mechanics. In recent years, the study of high energy plasmas and heavy ion collisions has emphasized the importance of developing the techniques of relativistic mechanics. The results of Linder et al (Phys. Rev. Lett. 95 0040401 (2005)) as well as the more recent work of Palacios et al (Phys. Rev. Lett. 103 253001 (2009)) and others, have shown that there must be a quantum theory with coherence in time. Such a theory, manifestly covariant under the transformations of special relativity with an invariant evolution parameter, such as that of Stueckelberg (Helv. Phys. Acta 14 322, 588 (1941); 15 23 (1942); see also R P Feynman Phys. Rev. 80 4401 and J S Schwinger Phys. Rev. 82 664 (1951)) could provide a suitable basis for the study of such questions, as well as many others for which the application of the standard methods of quantum field theory are difficult to manage, involving, in particular, local
All-optical time-resolved measurement of laser energy modulation in a relativistic electron beam
D. Xiang
2011-11-01
Full Text Available We propose and demonstrate an all-optical method to measure laser energy modulation in a relativistic electron beam. In this scheme the time-dependent energy modulation generated from the electron-laser interaction in an undulator is converted into time-dependent density modulation with a chicane, which is measured to infer the laser energy modulation. The method, in principle, is capable of simultaneously providing information on femtosecond time scale and 10^{-5} energy scale not accessible with conventional methods. We anticipate that this method may have wide applications in many laser-based advanced beam manipulation techniques.
Wagner, F; Deppert, O; Brabetz, C; Fiala, P; Kleinschmidt, A; Poth, P; Schanz, V A; Tebartz, A; Zielbauer, B; Roth, M; Stöhlker, T; Bagnoud, V
2016-05-20
We present a study of laser-driven ion acceleration with micrometer and submicrometer thick plastic targets. Using laser pulses with high temporal contrast and an intensity of the order of 10^{20} W/cm^{2} we observe proton beams with cutoff energies in excess of 85 MeV and particle numbers of 10^{9} in an energy bin of 1 MeV around this maximum. We show that applying the target normal sheath acceleration mechanism with submicrometer thick targets is a very robust way to achieve such high ion energies and particle fluxes. Our results are backed with 2D particle in cell simulations furthermore predicting cutoff energies above 200 MeV for acceleration based on relativistic transparency. This predicted regime can be probed after a few technically feasible adjustments of the laser and target parameters.
Abdelmadjid Maireche
2016-11-01
Full Text Available In this paper, we present a novel theoretical analytical perform further investigation for the exact solvability of relativistic quantum spectrum systems for modified Mie-type potential (m.m.t. potential is discussed for spin-1/2 particles by means Boopp’s shift method instead to solving deformed Dirac equation with star product, in the framework of noncommutativity three dimensional real space (NC: 3D-RS. The exact corrections for excited states are found straightforwardly for interactions in one-electron atoms by means of the standard perturbation theory. Furthermore, the obtained corrections of energies are depended on four infinitesimal parameter ,which induced by position-position noncommutativity, in addition to the discreet atomic quantum numbers: and (the angular momentum quantum number and we have also shown that, the usual states in ordinary two and three dimensional spaces are canceled and has been replaced by new degenerated sub-states in the new quantum symmetries of (NC: 3D-RS and we have also applied our obtained results to the case of modified Krazer-Futes potential.
Particle production in relativistic heavy-ion collisions with perturbative QCD
Zhang, Yi
The commissioning of the Relativistic Heavy Ion Collider (RHIC) opened new era in nuclear collision physics, with the study of excited strongly-interacting matter becoming a reality. A primary motivation for studying high-p T hadron production in ultrarelativistic heavy ion collisions is to gain insight into the gluon density of the quark-gluon medium via jet energy loss. The sensitivity of high-pT hadron spectra to initial gluon density may be a probe of the formation of quark-gluon-plasma (QGP). However, a thorough understanding of ultrarelativistic nuclear (AA ) collisions requires the accurate description of proton-proton ( pp) and proton-nucleus (pA) collisions in the same framework. In the present dissertation we follow the evolution of high-p T hadron production in relativistic collisions from pp to pA to AA reactions. The perturbative Quantum Chromodynamics (pQCD) improved parton model is used for the study. We apply leading-order (LO) pQCD throughout, and augment the standard one-dimensional cross section calculation by the intrinsic transverse momentum distribution of partons. We use abundant pion production data from pp collisions at c.m. energies s≲ 60 GeV to extract the width of the transverse momentum distribution of partons in the nucleon. This gives a satisfactory fit of pion and kaon production data in pp collisions in the 2 ≤ pT ≤ 6 GeV window. For the treatment of nuclear systems, we developed a model based on the enhancement of the width of the transverse momentum distribution of partons in the nuclear medium. An additional parameter is fitted to describe the Cronin effect (cross section enhancement in pA collisions relative to pp collisions) at these energies. Shadowing and the isospin asymmetry of heavy nuclei are taken into account. We tested the model on charged pion and kaon production. In AA collisions at SPS energies we find an indication of a need for a mechanism to decrease the calculated cross section of neutral pion production
Bakke, K
2015-01-01
The behaviour of a relativistic scalar particle in a possible scenario that arises from the violation of the Lorentz symmetry is investigated. The background of the Lorentz symmetry violation is defined by a tensor field that governs the Lorentz symmetry violation out of the Standard Model Extension. Thereby, we show that a Coulomb-type potential can be induced by Lorentz symmetry breaking effects and bound states solutions to the Klein-Gordon equation can be obtained. Further, we discuss the effects of this Coulomb-type potential on the confinement of the relativistic scalar particle to a linear confining potential by showing that bound states solutions to the Klein-Gordon equation can also be achieved, and obtain a quantum effect characterized by the dependence of a parameter of the linear confining potential on the quantum numbers $\\left\\{n,l\\right\\}$ of the system.
Scott, Tony C.
It has been shown that the Fokker-Wheeler-Feynman (FWF) model could be rewritten to yield a physically acceptable relativistic many-particle Lagrangian. Contrary to Wheeler and Feynman's postulates, the model satisfies causality and can be generalised to include arbitrary forces. The 1/c power series of the FWF Lagrangian to order (1/c) ^4 contains accelerations. A procedure of quantizing the theory for such a Lagrangian is presented and it is then found that the accelerations approximately introduce an independent harmonic mode which is in agreement with resonances recently observed in Positronium collisions processes. This result may be of fundamental physical importance and requires further investigation. However, the refinement of this calculation requires the creation of new computational tools. To this end, a new method is presented in which both the eigenfunctions and eigenenergies are determined algebraically as power series in the order parameter, where each coefficient of the series is obtained in closed form. This method avoids the complications of a basis set and makes extensive use of symbolic computation. It is then applied to two model problems, namely the one-body Dirac equation for testing purposes and a special case of the two-body Dirac equation for which one obtains previously unknown closed form solutions.
A new relativistic hydrodynamics code for high-energy heavy-ion collisions
Okamoto, Kazuhisa; Akamatsu, Yukinao; Nonaka, Chiho
2016-10-01
We construct a new Godunov type relativistic hydrodynamics code in Milne coordinates, using a Riemann solver based on the two-shock approximation which is stable under the existence of large shock waves. We check the correctness of the numerical algorithm by comparing numerical calculations and analytical solutions in various problems, such as shock tubes, expansion of matter into the vacuum, the Landau-Khalatnikov solution, and propagation of fluctuations around Bjorken flow and Gubser flow. We investigate the energy and momentum conservation property of our code in a test problem of longitudinal hydrodynamic expansion with an initial condition for high-energy heavy-ion collisions. We also discuss numerical viscosity in the test problems of expansion of matter into the vacuum and conservation properties. Furthermore, we discuss how the numerical stability is affected by the source terms of relativistic numerical hydrodynamics in Milne coordinates.
A new relativistic hydrodynamics code for high-energy heavy-ion collisions
Okamoto, Kazuhisa [Nagoya University, Department of Physics, Nagoya (Japan); Akamatsu, Yukinao [Nagoya University, Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI), Nagoya (Japan); Osaka University, Department of Physics, Toyonaka (Japan); Stony Brook University, Department of Physics and Astronomy, Stony Brook, NY (United States); Nonaka, Chiho [Nagoya University, Department of Physics, Nagoya (Japan); Nagoya University, Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI), Nagoya (Japan); Duke University, Department of Physics, Durham, NC (United States)
2016-10-15
We construct a new Godunov type relativistic hydrodynamics code in Milne coordinates, using a Riemann solver based on the two-shock approximation which is stable under the existence of large shock waves. We check the correctness of the numerical algorithm by comparing numerical calculations and analytical solutions in various problems, such as shock tubes, expansion of matter into the vacuum, the Landau-Khalatnikov solution, and propagation of fluctuations around Bjorken flow and Gubser flow. We investigate the energy and momentum conservation property of our code in a test problem of longitudinal hydrodynamic expansion with an initial condition for high-energy heavy-ion collisions. We also discuss numerical viscosity in the test problems of expansion of matter into the vacuum and conservation properties. Furthermore, we discuss how the numerical stability is affected by the source terms of relativistic numerical hydrodynamics in Milne coordinates. (orig.)
A new relativistic hydrodynamics code for high-energy heavy-ion collisions
Okamoto, Kazuhisa; Nonaka, Chiho
2016-01-01
We construct a new Godunov type relativistic hydrodynamics code in Milne coordinates, using a Riemann solver based on the two-shock approximation which is stable under existence of large shock waves. We check the correctness of the numerical algorithm by comparing numerical calculations and analytical solutions in various problems, such as shock tubes, expansion of matter into the vacuum, Landau-Khalatnikov solution, propagation of fluctuations around Bjorken flow and Gubser flow. We investigate the energy and momentum conservation property of our code in a test problem of longitudinal hydrodynamic expansion with an initial condition for high-energy heavy-ion collisions.We also discuss numerical viscosity in the test problems of expansion of matter into the vacuum and conservation properties. Furthermore, we discuss how the numerical stability is affected by the source terms of relativistic numerical hydrodynamics in Milne coordinates.
Abdelmadjid Maireche
2016-01-01
In this paper, we present a novel theoretical analytical perform further investigation for the exact solvability of relativistic quantum spectrum systems for modified Mie-type potential (m.m.t.) potential is discussed for spin-1/2 particles by means Boopp’s shift method instead to solving deformed Dirac equation with star product, in the framework of noncommutativity three dimensional real space (NC: 3D-RS). The exact corrections for excited states are found straightforwardly for interactions...
Azevedo, F S; Castro, Luis B; Filgueiras, Cleverson; Cogollo, D
2015-01-01
The planar quantum dynamics of spin-1/2 neutral particle interacting with electrical fields is considered. A set of first order differential equations are obtained directly from the planar Dirac equation with nonminimum coupling. New solutions of this system, in particular, for the Aharonov-Casher effect, are found and discussed in detail. Pauli equation is also obtained by studying the motion of the particle when it describes a circular path of constant radius. We also analyze the planar dynamics in the full space, including the $r=0$ region. The self-adjoint extension method is used to obtain the energy levels and wave functions of the particle for two particular values for the self-adjoint extension parameter. The energy levels obtained are analogous to the Landau levels and explicitly depend on the spin projection parameter.
Dynamical instability in a relativistic cylindrical shell composed of counter rotating particles
Kurita, Yasunari
2011-01-01
We give a perturbative analysis for an infinitesimally thin cylindrical shell composed of counter rotating collisionless particles, originally devised by Apostolatos and Thorne. They found a static solution of the shell and concluded by C-energy argument that it is stable. Recently, the present authors and Ida reanalyzed this system by evaluating the C-energy on the future null infinity and found that the system has an instability, though it was not shown how the system is unstable. In this paper, it is shown in the framework of the linear perturbation theory that, if the constituent particles move slowly, the static shell is unstable in the sense that the perturbation of its circumferential radius oscillates with exponentially growing amplitude, whereas if the speed of the constituent particle exceeds a critical value, the shell just expands or contracts exponentially with time.
Yerokhin, V A; Fritzsche, S
2014-01-01
Relativistic configuration-interaction calculations have been performed for the energy levels of the low-lying and core-excited states of beryllium-like argon, Ar$^{14+}$. These calculations include the one-loop QED effects as obtained by two different methods, the screening-potential approach as well as the model QED operator approach. The calculations are supplemented by a systematic estimation of uncertainties of theoretical predictions.
Spin Operator for the Relativistic Particle%相对论粒子的自旋算符
张鹏飞; 阮图南
2000-01-01
发展了关于相对论态自旋算符的系统理论.考虑了具有非零静质量的粒子情况.对带自旋的相对论粒子,通常的自旋算符需换为相对论的自旋算符.在Poincaré群不可约表示的框架里,构造了适用于粒子任意正则态的自旋算符,称为运动自旋.本文的讨论限于量子力学.随后将在量子场论中对此作进一步深入研究.%A systematic theory of the appropriate spin operators for the relativistic states is developed. This paper discusses it in particle case, i.e., the quantum mechanics problem. For a massive relativistic particle with arbitrary nonzero spin, the spin operator should be replaced with the relativistic one. In the frame of irreducible representation of Poincargroup, this spin operator, which is named as moving spin and applied to all the canonical states of the particle, is constructed. Further discussion on the concept of moving spin in the quantum field theory will be followed.
Chaos and Maps in Relativistic Dynamical Systems
Horwitz, L P
1999-01-01
The basic work of Zaslavskii et al showed that the classical non-relativistic electromagnetically kicked oscillator can be cast into the form of an iterative map on the phase space; the resulting evolution contains a stochastic flow to unbounded energy. Subsequent studies have formulated the problem in terms of a relativistic charged particle in interaction with the electromagnetic field. We review the structure of the covariant Lorentz force used to study this problem. We show that the Lorentz force equation can be derived as well from the manifestly covariant mechanics of Stueckelberg in the presence of a standard Maxwell field, establishing a connection between these equations and mass shell constraints. We argue that these relativistic generalizations of the problem are intrinsically inaccurate due to an inconsistency in the structure of the relativistic Lorentz force, and show that a reformulation of the relativistic problem, permitting variations (classically) in both the particle mass and the effective...
Dark Energy, Particle Physics and Cosmology
Turner, Michael S.
2012-05-01
Dark energy and cosmic acceleration is one of the three pillars of the current cosmological paradigm. Moreover, both raise fundamental issues in cosmology and particle physics. In particle physics, the dark energy problem is intimately related to the perplexing issue of why the quantum energy of the vacuum is so small. In cosmology, the nature of the dark energy is crucial to understanding the destiny of the Universe. I will discuss the status of current models for dark energy -- including vacuum energy and rolling scalar fields -- their implications for cosmology and for particle physics and how they can be tested by WFIRST. I will also address the status of the possibility that cosmic acceleration is explained by modifying or replacing general relativity.
Particle production and chemical freezeout from the hybrid UrQMD approach at NICA energies
Tawfik, Abdel Nasser; Shalaby, Asmaa G; Hanafy, Mahmoud; Sorin, Alexander; Rogachevsky, Oleg; Scheinast, Werner
2016-01-01
The energy dependence of various particle ratios is calculated within the Ultra-Relativistic Quantum Molecular Dynamics approach and compared with the hadron resonance gas (HRG) model and measurements from various experiments, including RHIC-BES, SPS and AGS. It is found that the UrQMD particle ratios agree well with the experimental results at the RHIC-BES energies. Thus, we have utilized UrQMD in simulating particle ratios at other beam energies down to 3 GeV, which will be accessed at NICA and FAIR future facilities. We observe that the particle ratios for crossover and first-order phase transition, implemented in the hybrid UrQMD v3.4, are nearly indistinguishable, especially at low energies (at large baryon chemical potentials or high density).
Particle production and chemical freezeout from the hybrid UrQMD approach at NICA energies
Nasser Tawfik, Abdel [Modern University for Technology and Information (MTI), Egyptian Center for Theoretical Physics (ECTP), Cairo (Egypt); World Laboratory for Cosmology and Particle Physics (WLCAPP), Cairo (Egypt); Abou-Salem, Loutfy I. [Benha University, Physics Department, Faculty of Science, Benha (Egypt); Shalaby, Asmaa G.; Hanafy, Mahmoud [World Laboratory for Cosmology and Particle Physics (WLCAPP), Cairo (Egypt); Benha University, Physics Department, Faculty of Science, Benha (Egypt); Sorin, Alexander [Joint Institute for Nuclear Research, Bogoliubov Laboratory of Theoretical Physics, Dubna, Moscow region (Russian Federation); Joint Institute for Nuclear Research, Veksler and Baldin Laboratory of High Energy Physics, Dubna, Moscow region (Russian Federation); National Research Nuclear University (MEPhI), Moscow (Russian Federation); Dubna International University, Dubna (Russian Federation); Rogachevsky, Oleg; Scheinast, Werner [Joint Institute for Nuclear Research, Veksler and Baldin Laboratory of High Energy Physics, Dubna, Moscow region (Russian Federation)
2016-10-15
The energy dependence of various particle ratios is calculated within the Ultra-relativistic Quantum Molecular Dynamics approach and compared with the hadron resonance gas (HRG) model and measurements from various experiments, including RHIC-BES, SPS and AGS. It is found that the UrQMD particle ratios agree well with the experimental results at the RHIC-BES energies. Thus, we have utilized UrQMD in simulating particle ratios at other beam energies down to 3GeV, which will be accessed at NICA and FAIR future facilities. We observe that the particle ratios for crossover and first-order phase transition, implemented in the hybrid UrQMD v3.4, are nearly indistinguishable, especially at low energies (at large baryon chemical potentials or high density). (orig.)
Mass spectrum bound state systems with relativistic corrections
Dineykhan, M; Zhaugasheva, S A [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation); Toinbaeva, N Sh; Jakhanshir, A [al-Farabi Kazak National University, 480012 Almaty (Kazakhstan)
2009-07-28
Based on the investigation of the asymptotic behaviour of the polarization loop function for charged n scalar particles in an external gauge field, we determine the interaction Hamiltonian including relativistic corrections. The mass spectrum of the bound state is analytically derived. The mechanism for arising of the constituent mass of the relativistic bound-state forming particles is explained. The mass and the constituent mass of the two-, three- and n-body relativistic bound states are calculated taking into account relativistic corrections. The corrections arising due to the one- and two-loop electron polarization to the energy spectrum of muonic hydrogen with orbital and radial excitations are calculated.
López, Rodrigo A. [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción, Concepción 4070386 (Chile); Muñoz, Víctor [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); Viñas, Adolfo F. [Geospace Physics Laboratory, Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States); Valdivia, Juan A. [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); Centro para el Desarrollo de la Nanociencia y la Nanotecnología (CEDENNA), Santiago 9170124 (Chile)
2015-09-15
We use a particle-in-cell simulation to study the propagation of localized structures in a magnetized electron-positron plasma with relativistic finite temperature. We use as initial condition for the simulation an envelope soliton solution of the nonlinear Schrödinger equation, derived from the relativistic two fluid equations in the strongly magnetized limit. This envelope soliton turns out not to be a stable solution for the simulation and splits in two localized structures propagating in opposite directions. However, these two localized structures exhibit a soliton-like behavior, as they keep their profile after they collide with each other due to the periodic boundary conditions. We also observe the formation of localized structures in the evolution of a spatially uniform circularly polarized Alfvén wave. In both cases, the localized structures propagate with an amplitude independent velocity.
2015-01-01
As a follow-up to a recent study in the spin-0 case [J. Bunao and E. A. Galapon, Ann. Phys. 353, 83-106 (2015)], we construct a one-particle Time of Arrival (TOA) operator conjugate to a Hamiltonian describing a free relativistic spin-1/2 particle in one spatial dimension. Upon transformation in a representation where the Hamiltonian is diagonal, it turns out that the constructed operator consists of an operator term $\\mathcal{\\hat{T}}$ whose action is the same as in the spin-0 case, and anot...
Ultrahigh-energy particles from cosmic strings
Bhattacharjee, P. (Chicago Univ., IL (USA). Astronomy and Astrophysics Center Fermi National Accelerator Lab., Batavia, IL (USA))
1991-02-01
The idea of production of ultrahigh-energy particles in the present universe due to annihilation or collapse of topological defects is discussed. Topological defects, formed in symmetry-breaking phase transitions in the early universe, can survive till today owing to their topological stability. However, under certain circumstances, topological defects may be physically destroyed. When topological defects are destroyed, the energy contained in the defects can be released in the form of massive gauge- and Higgs bosons of the underlying spontaneously broken gauge theory. Subsequent decay of these massive particles can give rise to energetic particles ranging up to an energy on the order of the mass of the original particles released from the defects. This may give us a natural'' mechanism of production of extremely energetic cosmic ray particles in the universe today, without the need for any acceleration mechanism. To illustrate this idea, I describe in detail the calculation of the expected ultrahigh-energy proton spectrum due to a specific process which involves collapse or multiple self-intersections of a class of closed cosmic string loops formed in a phase transition at a grand unification energy scale. I discuss the possibility that some of the highest-energy cosmic ray particles are of this origin. By comparing with the observational results on the ultrahigh-energy cosmic rays, we derive an upper limit to the average fraction of the total energy in all primary'' cosmic string loops that may be released in the form of particles due to collapse or multiple self-intersections of these loops. No nuclei such as {alpha}'s or Fe's are in the spectrum. 43 refs., 3 figs.
Zhang, C J; Hua, J F; Xu, X L; Li, F; Pai, C-H; Wan, Y; Wu, Y P; Gu, Y Q; Mori, W B; Joshi, C; Lu, W
2016-07-11
A new method capable of capturing coherent electric field structures propagating at nearly the speed of light in plasma with a time resolution as small as a few femtoseconds is proposed. This method uses a few femtoseconds long relativistic electron bunch to probe the wake produced in a plasma by an intense laser pulse or an ultra-short relativistic charged particle beam. As the probe bunch traverses the wake, its momentum is modulated by the electric field of the wake, leading to a density variation of the probe after free-space propagation. This variation of probe density produces a snapshot of the wake that can directly give many useful information of the wake structure and its evolution. Furthermore, this snapshot allows detailed mapping of the longitudinal and transverse components of the wakefield. We develop a theoretical model for field reconstruction and verify it using 3-dimensional particle-in-cell (PIC) simulations. This model can accurately reconstruct the wakefield structure in the linear regime, and it can also qualitatively map the major features of nonlinear wakes. The capturing of the injection in a nonlinear wake is demonstrated through 3D PIC simulations as an example of the application of this new method.
Zhang, C J; Xu, X L; Li, F; Pai, C -H; Wan, Y; Wu, Y P; Gu, Y Q; Mori, W B; Joshi, C; Lu, W
2016-01-01
A new method capable of capturing coherent electric field structures propagating at nearly the speed of light in plasma with a time resolution as small as a few femtoseconds is proposed. This method uses a few femtoseconds long relativistic electron bunch to probe the wake produced in a plasma by an intense laser pulse or an ultra-short relativistic charged particle beam. As the probe bunch traverses the wake, its momentum is modulated by the electric field of the wake, leading to a density variation of the probe after free-space propagation. This variation of probe density produces a snapshot of the wake that can directly give many useful information of the wake structure and its evolution. Furthermore, this snapshot allows detailed mapping of the longitudinal and transverse components of the wakefield. We develop a theoretical model for field reconstruction and verify it using 3-dimensional particle-in-cell (PIC) simulations. This model can accurately reconstruct the wakefield structure in the linear regime...
Zhang, C. J.; Hua, J. F.; Xu, X. L.; Li, F.; Pai, C.-H.; Wan, Y.; Wu, Y. P.; Gu, Y. Q.; Mori, W. B.; Joshi, C.; Lu, W.
2016-07-01
A new method capable of capturing coherent electric field structures propagating at nearly the speed of light in plasma with a time resolution as small as a few femtoseconds is proposed. This method uses a few femtoseconds long relativistic electron bunch to probe the wake produced in a plasma by an intense laser pulse or an ultra-short relativistic charged particle beam. As the probe bunch traverses the wake, its momentum is modulated by the electric field of the wake, leading to a density variation of the probe after free-space propagation. This variation of probe density produces a snapshot of the wake that can directly give many useful information of the wake structure and its evolution. Furthermore, this snapshot allows detailed mapping of the longitudinal and transverse components of the wakefield. We develop a theoretical model for field reconstruction and verify it using 3-dimensional particle-in-cell (PIC) simulations. This model can accurately reconstruct the wakefield structure in the linear regime, and it can also qualitatively map the major features of nonlinear wakes. The capturing of the injection in a nonlinear wake is demonstrated through 3D PIC simulations as an example of the application of this new method.
On the Origins of the Planck Zero Point Energy in Relativistic Quantum Field Theory
Widom, A; Srivastava, Y N
2015-01-01
It is argued that the zero point energy in quantum field theory is a reflection of the particle anti-particle content of the theory. This essential physical content is somewhat disguised in electromagnetic theory wherein the photon is its own anti-particle. To illustrate this point, we consider the case of a charged Boson theory $(\\pi^+,\\pi^-)$ wherein the particle and anti-particle can be distinguished by the charge $\\pm e$. Starting from the zero point energy, we derive the Boson pair production rate per unit time per unit volume from the vacuum in a uniform external electric field. The result is further generalized for arbitrary spin $s$.
Nakamura, Masanori
2014-01-01
We describe a new paradigm for understanding both relativistic motions and particle acceleration in the M87 jet: a magnetically dominated relativistic flow that naturally produces four relativistic magnetohydrodynamic (MHD) shocks (forward/reverse fast and slow modes). We apply this model to a set of optical super- and subluminal motions discovered by Biretta and coworkers with the {\\em Hubble Space Telescope} during 1994 -- 1998. The model concept consists of ejection of a {\\em single} relativistic Poynting jet, which possesses a coherent helical (poloidal + toroidal) magnetic component, at the remarkably flaring point HST-1. We are able to reproduce quantitatively proper motions of components seen in the {\\em optical} observations of HST-1 with the same model we used previously to describe similar features in radio VLBI observations in 2005 -- 2006. This indicates that the quad relativistic MHD shock model can be applied generally to recurring pairs of super/subluminal knots ejected from the upstream edge o...
Becker, Peter A.; Das, Santabrata; Le, Truong
2011-12-01
The acceleration of relativistic particles in a viscous accretion disk containing a standing shock is investigated as a possible explanation for the energetic outflows observed around radio-loud black holes. The energy/space distribution of the accelerated particles is computed by solving a transport equation that includes the effects of first-order Fermi acceleration, bulk advection, spatial diffusion, and particle escape. The velocity profile of the accreting gas is described using a model for shocked viscous disks recently developed by the authors, and the corresponding Green's function distribution for the accelerated particles in the disk and the outflow is obtained using a classical method based on eigenfunction analysis. The accretion-driven, diffusive shock acceleration scenario explored here is conceptually similar to the standard model for the acceleration of cosmic rays at supernova-driven shocks. However, in the disk application, the distribution of the accelerated particles is much harder than would be expected for a plane-parallel shock with the same compression ratio. Hence the disk environment plays a key role in enhancing the efficiency of the shock acceleration process. The presence of the shock helps to stabilize the disk by reducing the Bernoulli parameter, while channeling the excess binding energy into the escaping relativistic particles. In applications to M87 and Sgr A*, we find that the kinetic power in the jet is {\\sim}0.01\\,\\dot{M} c^2, and the outflowing relativistic particles have a mean energy ~300 times larger than that of the thermal gas in the disk at the shock radius. Our results suggest that a standing shock may be an essential ingredient in accretion onto underfed black holes, helping to resolve the long-standing problem of the stability of advection-dominated accretion disks.
Use of relativistic rise in ionization chambers for measurement of high energy heavy nuclei
Barthelmy, S. D.; Israel, M. H.; Klarmann, J.; Vogel, J. S.
1983-01-01
A balloon-borne instrument has been constructed to measure the energy spectra of cosmic-ray heavy nuclei in the range of about 0.3 to about 100 GeV/amu. It makes use of the relativistic rise portion of the Bethe-Bloch curve in ionization chambers for energy determination in the 10- to 100-GeV/amu interval. The instrument consists of six layers of dual-gap ionization chambers for energy determination above 10 GeV/amu. Charge is determined with a NE114 scintillator and a Pilot 425 plastic Cerenkov counter. A CO2 gas Cerenkov detector (1 atm; threshold of 30 GeV/amu) calibrates the ion chambers in the relativistic rise region. The main emphasis of the instrument is the determination of the change of the ratio of Iron (26) to the Iron secondaries (21-25) in the energy range of 10 to 100 GeV/amu. Preliminary data from a balloon flight in the fall of 1982 from Palestine, TX is presented.
Hidalgo-Gato, Rafael A Valls
2012-01-01
From a rigorous historic analysis of 1686 I. Newton and 1905 A. Einstein works where the last derived the universal mass-energy relationship, it is concluded that rest mass measures potential energy. From the same formula used to obtain that relation, it is derived the ratio Total Energy/Potential Energy is equal to the gamma relativistic factor. It is derived a formula for the variation of a body rest mass with its position in a gravity field, explaining with it the behavior of an atomic clock. It is revised the bodies free fall in a gravitational field, finding that a constant total mass is equal to the gravitational mass, while the variable rest mass is equal to the inertial mass, maintaining all an identical behavior independent of their masses. A revision of the E\\"otv\\"os experiment concludes that it is unable to detect the found difference between inertial and gravitational mass. Applying the extended 1905 relativistic dynamics to Mercury, its perihelion shift is determined; it is concluded with the co...
BRIGGS,S.L.K.; MUSOLINO,S.V.
2001-06-01
In early 1997 Brookhaven National Laboratory (BNL) discovered that the spent fuel pool of their High Flux Beam Reactor was leaking tritium into the groundwater. Community members, activist groups, politicians and regulators were outraged with the poor environmental management practices at BNL. The reactor was shut down and the Department of Energy (DOE) terminated the contract with the existing Management Company. At this same time, a major new scientific facility, the Relativistic Heavy Ion Collider (RHIC), was nearing the end of construction and readying for commissioning. Although environmental considerations had been incorporated into the design of the facility; some interested parties were skeptical that this new facility would not cause significant environmental impacts. RHIC management recognized that the future of its operation was dependent on preventing pollution and allaying concerns of its stakeholders. Although never done at a DOE National Laboratory before Brookhaven Science Associates, the new management firm, committed to implementing an Environmental Management System (EMS) and RHIC managers volunteered to deploy it within their facility on an extremely aggressive schedule. Several of these IS0 requirements contribute directly to preventing pollution, an area where particular emphasis was placed. This paper describes how Brookhaven used the following key IS0 14001 elements to institutionalize Pollution Prevention concepts: Environmental Policy, Aspects, Objectives and Targets, Environmental Management Program, Structure and Responsibility, Operational Controls, Training, and Management Review. In addition, examples of implementation at the RHIC Project illustrate how BNL's premiere facility was able to demonstrate to interested parties that care had been taken to implement technological and administrative controls to minimize environmental impacts, while at the same time reduce the applicability of regulatory requirements to their operations.
Boundedness of the total energy of relativistic membranes evolving in a curved spacetime
LeFloch, Philippe G
2016-01-01
We establish a global existence theory for the equation governing the evolution of a relativistic membrane in a (possibly curved) Lorentzian manifold, when the spacetime metric is a perturbation of the Minkowski metric. Relying on the Hyperboloidal Foliation Method introduced by LeFloch and Ma in 2014, we revisit a theorem established earlier by Lindblad (who treated membranes in the flat Minkowski spacetime) and we provide a simpler proof of existence, which is also valid in a curved spacetime and, most importantly, leads to the important property that the total energy of the membrane is globally bounded in time.
High efficiency energy extraction from a relativistic electron beam in a strongly tapered undulator
Sudar, Nicholas; Duris, Joe; Gadjev, Ivan; Polyaniy, Mikhail; Pogorelsky, Igor; Fedurin, Mikhail; Swinson, Christina; Babzien, Marcus; Kusche, Karl; Gover, Avi
2016-01-01
We present results of an experiment where, using a 200 GW CO2 laser seed, a 65 MeV electron beam was decelerated down to 35 MeV in a 54 cm long strongly tapered helical magnetic undulator, extracting over 30$\\%$ of the initial electron beam energy to coherent radiation. These results demonstrate unparalleled electro-optical conversion efficiencies for a relativistic beam in an undulator field and represent an important step in the development of high peak and average power coherent radiation sources.
High Efficiency Energy Extraction from a Relativistic Electron Beam in a Strongly Tapered Undulator
Sudar, N.; Musumeci, P.; Duris, J.; Gadjev, I.; Polyanskiy, M.; Pogorelsky, I.; Fedurin, M.; Swinson, C.; Kusche, K.; Babzien, M.; Gover, A.
2016-10-01
We present results of an experiment where, using a 200 GW CO2 laser seed, a 65 MeV electron beam was decelerated down to 35 MeV in a 54-cm-long strongly tapered helical magnetic undulator, extracting over 30% of the initial electron beam energy to coherent radiation. These results, supported by simulations of the radiation field evolution, demonstrate unparalleled electro-optical conversion efficiencies for a relativistic beam in an undulator field and represent an important step in the development of high peak and average power coherent radiation sources.
Hernandez-Zapata, Sergio; 10.1007/s10701-010-9413-7
2010-01-01
A completely Lorentz-invariant Bohmian model has been proposed recently for the case of a system of non-interacting spinless particles, obeying Klein-Gordon equations. It is based on a multi-temporal formalism and on the idea of treating the squared norm of the wave function as a space-time probability density. The particle's configurations evolve in space-time in terms of a parameter {\\sigma}, with dimensions of time. In this work this model is further analyzed and extended to the case of an interaction with an external electromagnetic field. The physical meaning of {\\sigma} is explored. Two special situations are studied in depth: (1) the classical limit, where the Einsteinian Mechanics of Special Relativity is recovered and the parameter {\\sigma} is shown to tend to the particle's proper time; and (2) the non-relativistic limit, where it is obtained a model very similar to the usual non-relativistic Bohmian Mechanics but with the time of the frame of reference replaced by {\\sigma} as the dynamical temporal...
Particle creation with finite energy density
Dray, Tevian; Renn, Jürgen; Salisbury, Donald
1983-03-01
We consider the semiclassical quantization of the Klein—Gordon field on a Robertson—Walker background with a flat-out region. We show that the requirement that the energy density of created particles be finite selects a preferred equivalence class of particle definitions. We present a representative element of the equivalence class so determined. We briefly discuss the generalization to Bianchi I spacetimes, and the case of an external Maxwell field.
E. V. B. Leite
2015-01-01
Full Text Available Based on the Kaluza-Klein theory, we study the Aharonov-Bohm effect for bound states for a relativistic scalar particle subject to a Coulomb-type potential. We introduce this scalar potential as a modification of the mass term of the Klein-Gordon equation, and a magnetic flux through the line element of the Minkowski spacetime in five dimensions. Then, we obtain the relativistic bound states solutions and calculate the persistent currents.
Threshold fracture energy in solid particle erosion
Argatov, I I; Petrov, Yu V
2012-01-01
The effect of geometrical shape of eroding absolutely rigid particles on the threshold rate of failure has been studied. The Shtaerman-Kilchevsky theory of quasi-static blunt impact, which generalizes Hertz's classical impact theory, is used for modeling the frictionless contact interaction of an axially-symmetric particle with an elastic half-space. The incubation time fracture criterion is applied for predicting surface fracture. It is shown that there exist a critical value of the particle shape parameter such that for all its lower values the fracture energy possesses a nonzero minimal value.
High energy particle collisions near black holes
Zaslavskii O. B.
2016-01-01
Full Text Available If two geodesic particles collide near a rotating black hole, their energy in the centre of mass frame Ec.m. can become unbound under certain conditions (the so-called BSW effect. The special role is played here by so-called critical geodesics when one of particles has fine-tuned energy and angular momentum. The nature of geodesics reveals itself also in fate of the debris after collisions. One of particles moving to a remote observer is necessarily near-critical. We discuss, when such a collision can give rise not only unboud Ec.m. but also unbound Killing energy E (so-called super-Penrose process.
Mori, M; Daito, I; Kotaki, H; Hayashi, Y; Yamazaki, A; Ogura, K; Sagisaka, A; Koga, J; Nakajima, K; Daido, H; Bulanov, S V; Kimura, T
2006-01-01
The regimes of quasi-mono-energetic electron beam generation were experimentally studied in the sub-relativistic intensity laser plasma interaction. The observed electron acceleration regime is unfolded with two-dimensional-particle-in-cell simulations of laser-wakefield generation in the self-modulation regime.
John R. Fanchi
2017-07-01
Full Text Available Jüttner used the conventional theory of relativistic statistical mechanics to calculate the energy of a relativistic ideal gas in 1911. An alternative derivation of the energy of a relativistic ideal gas was published by Horwitz, Schieve and Piron in 1981 within the context of parametrized relativistic statistical mechanics. The resulting energy in the ultrarelativistic regime differs from Jüttner’s result. We review the derivations of energy and identify physical regimes for testing the validity of the two theories in accelerator physics and cosmology.
2002-01-01
% EMU11 \\\\ \\\\ We propose to use nuclear emulsions for the study of nuclear collisions of $^{207}$Pb, $^{197}$Au, and any other heavy-ion beams when they are available. We have, in the past, used $^{32}$S at 200A~GeV and $^{16}$O at 200A and 60A~GeV from CERN (Experiment EMU08) and at present the analysis is going on with $^{28}$Si beam from BNL at 14.5A~GeV. It will be important to compare the previous and the present investigations with the new $^{207}$Pb beam at 60-160A~GeV. We want to measure in nuclear emulsion, on an event by event basis, shower particle multiplicity, pseudorapidity density and density fluctuations of charged particles, charge multiplicity and angular distributions of projectile fragments, production and interaction cross-sections of heavily ionizing particles emitted from the target fragmentation. Special emphasis will be placed on the analysis of events produced in the central collisions which are selected on the basis of low energy fragments emitted from the target excitation. It woul...
Polko, P.; Meier, D.L.; Markoff, S.
2013-01-01
We present a new, approximate method for modelling the acceleration and collimation of relativistic jets in the presence of gravity. This method is self-similar throughout the computational domain where gravitational effects are negligible and, where significant, self-similar within a flux tube.
Relativistic Treatment of Spinless Particles Subject to a Tietz-Wei Oscillator
孙国华; 董世海
2012-01-01
The bound state solutions of the relativistic Klein-Gordon equation with the Tietz-Wei diatomic molecular potential are presented for the s wave. It is shown that the solutions can be expressed by the generalized hypergeometric functions. The normalized wavefunctions are also derived.
Bargmann-Michel-Telegdi equation and one-particle relativistic approach
Della Selva, A; Masperi, L
1995-01-01
A reexamination of the semiclassical approach of the relativistic electron indicates a possible variation of its helicity for electric and magnetic static fields applied along its global motion due to zitterbewegung effects, proportional to the anomalous part of the magnetic moment.
Itoh, Yousuke
2009-01-01
We report our rederivation of the equations of motion for relativistic compact binaries through the third-and-a-half post-Newtonian (3.5 PN) order approximation to general relativity using the strong field point particle limit to describe self-gravitating stars instead of the Dirac delta functional. The computation is done in harmonic coordinates. Our equations of motion describe the orbital motion of the binary consisting of spherically symmetric non-rotating stars. The resulting equations of motion fully agree with the 3.5 PN equations of motion derived in the previous works. We also show that the locally defined energy of the star has a simple relation with its mass up to the 3.5 PN order.
On the Casimir energy for a 2N-piece relativistic string
Brevik, I
1997-01-01
The Casimir energy for the transverse oscillations of a piecewise uniform closed string is calculated. The string consists of 2N pieces of equal length, of alternating type I and type II material, and is taken to be relativistic in the sense that the velocity of sound always equals the velocity of light. By means of a new recursion formula we manage to calculate the Casimir energy for arbitrary integers N. Agreement with results obtained in earlier works on the string is found in all special cases. As basic regularization method we use the contour integration method. As a check, agreement is found with results obtained from the \\zeta function method (the Hurwitz function) in the case of low N (N = 1-4). The Casimir energy is generally negative, and the more so the larger is the value of N. We illustrate the results graphically in some cases. The generalization to finite temperature theory is also given.
Some Effects on A Single Particle Energies
WANG Qiu-Ling; LUO Yan-An; CAI Chong-Hai; NING Ping-Zhi
2002-01-01
With the phenomenological A-nucleus potentials of Woods-Saxon shape,the effects of the maas-number dependence of the shrinkage,the effective mass m*^ and the charge-symmetry breaking (CSB) on the single particle energies are discussed.It is found that the single particle energies are not sensitive to the effective mass m*^.But the radius parameter depended on the mass number (ro (Ac) = r1 + r2A-2/3) can substantially improve the results.We also found that CSB effect is significant for heavy hypernuclei with a large neutron excess.
Pallocchia, G.; Laurenza, M.; Consolini, G.
2017-03-01
Some interplanetary shocks are associated with short-term and sharp particle flux enhancements near the shock front. Such intensity enhancements, known as shock-spike events (SSEs), represent a class of relatively energetic phenomena as they may extend to energies of some tens of MeV or even beyond. Here we present an SSE case study in order to shed light on the nature of the particle acceleration involved in this kind of event. Our observations refer to an SSE registered on 2011 October 3 at 22:23 UT, by STEREO B instrumentation when, at a heliocentric distance of 1.08 au, the spacecraft was swept by a perpendicular shock moving away from the Sun. The main finding from the data analysis is that a Weibull distribution represents a good fitting function to the measured particle spectrum over the energy range from 0.1 to 30 MeV. To interpret such an observational result, we provide a theoretical derivation of the Weibull spectrum in the framework of the acceleration by “killed” stochastic processes exhibiting power-law growth in time of the velocity expectation, such as the classical Fermi process. We find an overall coherence between the experimental values of the Weibull spectrum parameters and their physical meaning within the above scenario. Hence, our approach based on the Weibull distribution proves to be useful for understanding SSEs. With regard to the present event, we also provide an alternative explanation of the Weibull spectrum in terms of shock-surfing acceleration.
Laser-driven micro-Coulomb charge movement and energy conversion to relativistic electrons
Cobble, J. A.; Palaniyappan, S.; Johnson, R. P.; Shimada, T.; Huang, C.; Gautier, D. C.; Clark, D. D.; Falk, K.; Jung, D.
2016-09-01
Development of robust instrumentation has shown evidence for a multi-μC expulsion of relativistic electrons from a sub-μm-thick foil, laser illuminated with 60-70 J on target at 2 × 1020 W/cm2. From previous work and with electron spectroscopy, it is seen that an exponential electron energy distribution is accurate enough to calculate the emitted electron charge and energy content. The 5-10-μC charge for the >100-TW Trident Laser represents the first active measurement of the >50% laser-light-to-electron conversion efficiency. By shorting out the TV/m electric field usually associated with accelerating multi-MeV ions from such targets, one finds that this charge is representative of a multi-MA current of relativistic electrons for diverse applications from electron fast ignition to advanced radiography concepts. Included with the details of the discoveries of this research, shortcomings of the diagnostics and means of improving their fidelity are discussed.
De Soto, F
2006-01-01
The numerical solutions of the non-relativistic Yukawa model on a 3-dimensional size lattice with periodic boundary conditions are obtained. The possibility to extract the corresponding -- infinite space -- low energy parameters and bound state binding energies from eigensates computed at finite lattice size is discussed.
Luciano, Rezzolla
2013-01-01
Relativistic hydrodynamics is a very successful theoretical framework to describe the dynamics of matter from scales as small as those of colliding elementary particles, up to the largest scales in the universe. This book provides an up-to-date, lively, and approachable introduction to the mathematical formalism, numerical techniques, and applications of relativistic hydrodynamics. The topic is typically covered either by very formal or by very phenomenological books, but is instead presented here in a form that will be appreciated both by students and researchers in the field. The topics covered in the book are the results of work carried out over the last 40 years, which can be found in rather technical research articles with dissimilar notations and styles. The book is not just a collection of scattered information, but a well-organized description of relativistic hydrodynamics, from the basic principles of statistical kinetic theory, down to the technical aspects of numerical methods devised for the solut...
Power Supplies for High Energy Particle Accelerators
Dey, Pranab Kumar
2016-06-01
The on-going research and the development projects with Large Hadron Collider at CERN, Geneva, Switzerland has generated enormous enthusiasm and interest amongst all to know about the ultimate findings on `God's Particle'. This paper has made an attempt to unfold the power supply requirements and the methodology adopted to provide the stringent demand of such high energy particle accelerators during the initial stages of the search for the ultimate particles. An attempt has also been made to highlight the present status on the requirement of power supplies in some high energy accelerators with a view that, precautionary measures can be drawn during design and development from earlier experience which will be of help for the proposed third generation synchrotron to be installed in India at a huge cost.
Studies of High Energy Particle Astrophysics
Nitz, David F [Michigan Technological University; Fick, Brian E [Michigan Technological University
2014-07-30
This report covers the progress of the Michigan Technological University particle astrophysics group during the period April 15th, 2011 through April 30th, 2014. The principal investigator is Professor David Nitz. Professor Brian Fick is the Co-PI. The focus of the group is the study of the highest energy cosmic rays using the Pierre Auger Observatory. The major goals of the Pierre Auger Observatory are to discover and understand the source or sources of cosmic rays with energies exceeding 10**19 eV, to identify the particle type(s), and to investigate the interactions of those cosmic particles both in space and in the Earth's atmosphere. The Pierre Auger Observatory in Argentina was completed in June 2008 with 1660 surface detector stations and 24 fluorescence telescopes arranged in 4 stations. It has a collecting area of 3,000 square km, yielding an aperture of 7,000 km**2 sr.
LUO Xiao-hua; WU Mu-ying; HE Wei; SHAO Ming-zhu; LUO Shi-yu
2011-01-01
Under classical mechanics, the general equation of particle motion in the periodic field is derived. In the dampless case, the existence possibility of the higher-order harmonic radiation is explored by using Bessel function expansion of a generalized trigonometrical function and the multi-scale method. In the damping case, the critical properties and a chaotic behavior are discussed by the Melnikov method. The results show that the use of a higher-order harmonic radiation of non-relativistic particles as a short-wavelength laser source is perfectly possible, and the system's critical condition is related to its parameters. Only by adjusting parameters suitablely, the stable higher-order harmonic radiation with bigger intensity can be obtained.
Hanbury Brown-Twiss Interferometry in High Energy Nuclear and Particle Physics
Heinz, Ulrich W
1998-01-01
I review recent applications of two-particle intensity interferometry in high energy physics, concentrating on relativistic heavy ion collisions. By measuring hadronic single-particle spectra and two-particle correlations in hadron-hadron or heavy-ion collisions, the size and dynamical state of the collision fireball at freeze-out can be reconstructed. I discuss the relevant theoretical methods and their limitations. By applying the formalism to recent pion correlation data from Pb+Pb collisions at CERN we demonstrate that the collision zone has undergone strong transverse growth before freeze-out (by a factor 2 in each direction), and that it expands both longitudinally and transversally. From the thermal and flow energy density at freeze-out the energy density at the onset of transverse expansion can be estimated from conservation laws. It comfortably exceeds the critical value for the transition to color deconfined matter.
Calculation of Energy Spectrum of 12C Isotope by Relativistic Cluster model
Roshanbakht, Nafiseh
2016-01-01
In this paper, we have calculated the energy spectrum of 12C isotope by cluster model. The experimental results show that the "Hoyle" state at 7.65 MeV in 12C isotope has a well-developed three-alpha structure. Hence, we select a three-body system and for interaction between the clusters we use modified Yukawa potential plus coulomb potential. Then, we solve the relativistic Klein-Gordon equation using Nikiforov-Uvarov method to calculate the energy spectrum. Finally, the calculated results are compared with the experimental data. The results show that the isotope 12C should be considered as consisting of three-alpha cluster and the modified Yukawa potential is adaptable for cluster interactions.
Enhanced relativistic-electron-beam energy loss in warm dense aluminum.
Vaisseau, X; Debayle, A; Honrubia, J J; Hulin, S; Morace, A; Nicolaï, Ph; Sawada, H; Vauzour, B; Batani, D; Beg, F N; Davies, J R; Fedosejevs, R; Gray, R J; Kemp, G E; Kerr, S; Li, K; Link, A; McKenna, P; McLean, H S; Mo, M; Patel, P K; Park, J; Peebles, J; Rhee, Y J; Sorokovikova, A; Tikhonchuk, V T; Volpe, L; Wei, M; Santos, J J
2015-03-01
Energy loss in the transport of a beam of relativistic electrons in warm dense aluminum is measured in the regime of ultrahigh electron beam current density over 2×10^{11} A/cm^{2} (time averaged). The samples are heated by shock compression. Comparing to undriven cold solid targets, the roles of the different initial resistivity and of the transient resistivity (upon target heating during electron transport) are directly observable in the experimental data, and are reproduced by a comprehensive set of simulations describing the hydrodynamics of the shock compression and electron beam generation and transport. We measured a 19% increase in electron resistive energy loss in warm dense compared to cold solid samples of identical areal mass.
Ultra high energy cosmic rays from non-relativistic quasar outflows
Wang, Xiawei
2016-01-01
It has been suggested that non-relativistic outflows from quasars can naturally account for the missing component of the extragalactic $\\gamma$-ray background and explain the cumulative neutrino background through pion decay in collisions between protons accelerated by the outflow shock and interstellar protons. Here we show that the same quasar outflows are capable of accelerating protons to energies of $\\sim 10^{20}$ eV during the early phase of their propagation. The overall quasar population is expected to produce a cumulative ultra high energy cosmic ray flux of $\\sim10^{-7}\\,\\rm GeV\\,cm^{-2}s^{-1}sr^{-1}$ at $E_{\\rm CR}\\gtrsim10^{18}$ eV. The spectral shape and amplitude is consistent with recent observations for outflow parameters constrained to fit secondary $\\gamma$-rays and neutrinos without any additional parameter tuning. This indicates that quasar outflows simultaneously account for all three messengers at their observed levels.
Vector Theory in Relativistic Thermodynamics
刘泽文
1994-01-01
It is pointed out that five defects occur in Planck-Einstein’s relativistic thermodynamics (P-E theory). A vector theory in relativistic thermodynamics (VTRT) is established. Defining the internal energy as a 4-vector, and supposing the entropy and the number of. particles to be invariants we have derived the transformations of all quantities, and subsequently got the Lagrangian and 4-D forms of thermodynamic laws. In order to test the new theory, several exact solutions with classical limits are given. The VTRT is free from the defects of the P-E theory.
S. W. H. Cowley
2006-03-01
Full Text Available Recent spectroscopic observations of Jupiter's "main oval" auroras indicate that the primary auroral electron beam is routinely accelerated to energies of ~100 keV, and sometimes to several hundred keV, thus approaching the relativistic regime. This suggests the need to re-examine the classic non-relativistic theory of auroral electron acceleration by field-aligned electric fields first derived by Knight (1973, and to extend it to cover relativistic situations. In this paper we examine this problem for the case in which the source population is an isotropic Maxwellian, as also assumed by Knight, and derive exact analytic expressions for the field-aligned current density (number flux and kinetic energy flux of the accelerated population, for arbitrary initial electron temperature, acceleration potential, and field strength beneath the acceleration region. We examine the limiting behaviours of these expressions, their regimes of validity, and their implications for auroral acceleration in planetary magnetospheres (and like astrophysical systems. In particular, we show that for relativistic accelerating potentials, the current density increases as the square of the minimum potential, rather than linearly as in the non-relativistic regime, while the kinetic energy flux then increases as the cube of the potential, rather than as the square.
Whirling Waves and the Aharonov-Bohm Effect for Relativistic Spinning Particles
Girotti, H O
1996-01-01
The formulation of Berry for the Aharonov-Bohm effect is generalized to the relativistic regime. Then, the problem of finding the self-adjoint extensions of the (2+1)-dimensional Dirac Hamiltonian, in an Aharonov-Bohm background potential, is solved in a novel way. The same treatment also solves the problem of finding the self-adjoint extensions of the Dirac Hamiltonian in a background Aharonov-Casher.
The challenge of turbulent acceleration of relativistic particles in the intra-cluster medium
Brunetti, G
2015-01-01
Acceleration of cosmic-ray electrons (CRe) in the intra-cluster-medium (ICM) is probed by radio observations that detect diffuse, Mpc-scale, synchrotron sources in a fraction of galaxy clusters. Giant radio halos are the most spectacular manifestations of non-thermal activity in the ICM and are currently explained assuming that turbulence driven during massive cluster-cluster mergers reaccelerates CRe at several GeV. This scenario implies a hierarchy of complex mechanisms in the ICM that drain energy from large-scales into electromagnetic fluctuations in the plasma and collisionless mechanisms of particle acceleration at much smaller scales. In this paper we focus on the physics of acceleration by compressible turbulence. The spectrum and damping mechanisms of the electromagnetic fluctuations, and the mean-free-path (mfp) of CRe are the most relevant ingredients that determine the efficiency of acceleration. These ingredients in the ICM are however poorly known and we show that calculations of turbulent accel...
Low-energy effective field theory for finite-temperature relativistic superfluids
Nicolis, Alberto
2011-01-01
We derive the low-energy effective action governing the infrared dynamics of relativistic superfluids at finite temperature. We organize our derivation in an effective field theory fashion-purely in terms of infrared degrees of freedom and symmetries. Our degrees of freedom are the superfluid phase \\psi, and the comoving coordinates for the volume elements of the normal fluid component. The presence of two sound modes follows straightforwardly from Taylor-expanding the action at second order in small perturbations. We match our description to more conventional hydrodynamical ones, thus linking the functional form of our Lagrangian to the equation of state, which we assume as an input. We re-derive in our language some standard properties of relativistic superfluids in the high-temperature and low-temperature limits. As an illustration of the efficiency of our methods, we compute the cross-section for a sound wave (of either type) scattering off a superfluid vortex at temperatures right beneath the critical on...
Sun, Lingpeng; Klecker, Berndt; Krucker, Saem; Droege, Wolfgang
2010-01-01
We report for several solar energetic particle events intensity and anisotropy measurements of energetic electrons in the energy range ~ 27 to ~ 500 keV as observed with the Wind and ACE spacecraft in June 2000. The observations onboard Wind show bimodal pitch angle distributions (PAD), whereas ACE shows PADs with one peak, as usually observed for impulsive injection of electrons at the Sun. During the time of observation Wind was located upstream of the Earth's bow shock, in the dawn - noon sector, at distances of ~ 40 to ~ 70 Earth radii away from the Earth, and magnetically well connected to the quasi-parallel bow shock, whereas ACE, located at the libration point L1, was not connected to the bow shock. The electron intensity-time profiles and energy spectra show that the backstreaming electrons observed at Wind are not of magnetospheric origin. The observations rather suggest that the bi-modal electron PADs are due to reflection or scattering at an obstacle located at a distance of less than ~ 150 Earth r...
Particle Production in Strong Electromagnetic Fields in Relativistic Heavy-Ion Collisions
Kirill Tuchin
2013-01-01
Full Text Available I review the origin and properties of electromagnetic fields produced in heavy-ion collisions. The field strength immediately after a collision is proportional to the collision energy and reaches ~mπ2 at RHIC and ~10mπ2 at LHC. I demonstrate by explicit analytical calculation that after dropping by about one-two orders of magnitude during the first fm/c of plasma expansion, it freezes out and lasts for as long as quark-gluon plasma lives as a consequence of finite electrical conductivity of the plasma. Magnetic field breaks spherical symmetry in the direction perpendicular to the reaction plane, and therefore all kinetic coefficients are anisotropic. I examine viscosity of QGP and show that magnetic field induces azimuthal anisotropy on plasma flow even in spherically symmetric geometry. Very strong electromagnetic field has an important impact on particle production. I discuss the problem of energy loss and polarization of fast fermions due to synchrotron radiation, consider photon decay induced by magnetic field, elucidate J/ψ dissociation via Lorentz ionization mechanism, and examine electromagnetic radiation by plasma. I conclude that all processes in QGP are affected by strong electromagnetic field and call for experimental investigation.
Ndome, Hameth; Eisfeld, Wolfgang
2012-08-01
A new method has been reported recently [H. Ndome, R. Welsch, and W. Eisfeld, J. Chem. Phys. 136, 034103 (2012)], 10.1063/1.3675846 that allows the efficient generation of fully coupled potential energy surfaces (PESs) including derivative and spin-orbit (SO) coupling. The method is based on the diabatic asymptotic representation of the molecular fine structure states and an effective relativistic coupling operator and therefore is called effective relativistic coupling by asymptotic representation (ERCAR). The resulting diabatic spin-orbit coupling matrix is constant and the geometry dependence of the coupling between the eigenstates is accounted for by the diabatization. This approach allows to generate an analytical model for the fully coupled PESs without performing any ab initio SO calculations (except perhaps for the atoms) and thus is very efficient. In the present work, we study the performance of this new method for the example of hydrogen iodide as a well-established test case. Details of the diabatization and the accuracy of the results are investigated in comparison to reference ab initio calculations. The energies of the adiabatic fine structure states are reproduced in excellent agreement with reference ab initio data. It is shown that the accuracy of the ERCAR approach mainly depends on the quality of the underlying ab initio data. This is also the case for dissociation and vibrational level energies, which are influenced by the SO coupling. A method is presented how one-electron operators and the corresponding properties can be evaluated in the framework of the ERCAR approach. This allows the computation of dipole and transition moments of the fine structure states in good agreement with ab initio data. The new method is shown to be very promising for the construction of fully coupled PESs for more complex polyatomic systems to be used in quantum dynamics studies.
Relativistic quantum mechanics
Wachter, Armin
2010-01-01
Which problems do arise within relativistic enhancements of the Schrödinger theory, especially if one adheres to the usual one-particle interpretation, and to what extent can these problems be overcome? And what is the physical necessity of quantum field theories? In many books, answers to these fundamental questions are given highly insufficiently by treating the relativistic quantum mechanical one-particle concept very superficially and instead introducing field quantization as soon as possible. By contrast, this monograph emphasizes relativistic quantum mechanics in the narrow sense: it extensively discusses relativistic one-particle concepts and reveals their problems and limitations, therefore motivating the necessity of quantized fields in a physically comprehensible way. The first chapters contain a detailed presentation and comparison of the Klein-Gordon and Dirac theory, always in view of the non-relativistic theory. In the third chapter, we consider relativistic scattering processes and develop the...
Cosmic absorption of ultra high energy particles
Ruffini, R.; Vereshchagin, G. V.; Xue, S.-S.
2016-02-01
This paper summarizes the limits on propagation of ultra high energy particles in the Universe, set up by their interactions with cosmic background of photons and neutrinos. By taking into account cosmic evolution of these backgrounds and considering appropriate interactions we derive the mean free path for ultra high energy photons, protons and neutrinos. For photons the relevant processes are the Breit-Wheeler process as well as the double pair production process. For protons the relevant reactions are the photopion production and the Bethe-Heitler process. We discuss the interplay between the energy loss length and mean free path for the Bethe-Heitler process. Neutrino opacity is determined by its scattering off the cosmic background neutrino. We compute for the first time the high energy neutrino horizon as a function of its energy.
High Energy Particles in the Solar Corona
Widom, A; Larsen, L
2008-01-01
Collective Ampere law interactions producing magnetic flux tubes piercing through sunspots into and then out of the solar corona allow for low energy nuclear reactions in a steady state and high energy particle reactions if a magnetic flux tube explodes in a violent event such as a solar flare. Filamentous flux tubes themselves are vortices of Ampere currents circulating around in a tornado fashion in a roughly cylindrical geometry. The magnetic field lines are parallel to and largely confined within the core of the vortex. The vortices may thereby be viewed as long current carrying coils surrounding magnetic flux and subject to inductive Faraday and Ampere laws. These laws set the energy scales of (i) low energy solar nuclear reactions which may regularly occur and (ii) high energy electro-weak interactions which occur when magnetic flux coils explode into violent episodic events such as solar flares or coronal mass ejections.
Loveland, W.D.
1991-08-01
The work described herein is part of a project involving the study of low energy (< 10 MeV/A), intermediate energy (10--100 MeV/A) and relativistic (> 250 MeV/A) heavy ion reactions. In the low energy regime, we published a monograph on the properties of the heaviest elements and used that publication as a basis for making a set of ``best`` semi-empirical predictions of heavy element decay properties. The intermediate energy research effort focussed upon the completion of studies already begun and the initiation of a number of new experiments. In our study of a interaction of 21 MeV/nucleon {sup 129}Xe with {sup 197}Au, we compared the characteristics of the observed deep inelastic phenomena with various models of dissipative reactions and found significant discrepancies between observations and predictions. These discrepancies seemed to be caused by an improper treatment of pre-equilibrium in the early stages of the collision. In our study of the relativistic interaction of 400 MeV/nucleon {sup 12}C with {sup 197}Au, we reported the first direct physical measurement of the properties of the spallation residues from a nucleus-nucleus collision. We found the residue energies to be much lower than those predicted by the intranuclear cascade model, indicating some substantial modifications of that model are needed. But, we also found, indications of significant, non-zero values of the residue transverse momentum, a finding that calls into question the interpretation of a number of radiochemical recoil studies of the kinematics of high energy reactions. A program of performing numerical simulations of intermediate and high energy nuclear collisions using the QMD model was initiated.
Sahoo, Raghunath
2016-01-01
This lecture note covers Relativistic Kinematics, which is very useful for the beginners in the field of high-energy physics. A very practical approach has been taken, which answers "why and how" of the kinematics useful for students working in the related areas.
Energy loss distributions of relativistic protons axially channeled in a bent silicon crystal
Stojanov, Nace; Petrović, Srdjan; Nešković, Nebojša
2013-05-01
A detailed study of the energy loss distributions of the relativistic protons axially channeled in the bent Si crystals is presented in this work. The bending angle was varied from 0 to 20 μrad, while the crystal thickness was equal to 1 mm. The proton energy was chosen to be 7 TeV in accordance with the Large Hadron Collider (LHC) project, at the European Organization for Nuclear Research (CERN), in Geneva, Switzerland. The energy loss distributions of the channeled protons were generated using the numerical solution of the proton equations of motion in the transverse plane and the computer simulation method. An accurate energy loss model was used, which takes into account the trajectory dependence of the energy loss of protons during their motion through the crystal channels. Further, the dispersion of the proton's scattering angle caused by its collisions with the electrons of the crystal and the divergence of the proton beam were taken into account. The calculated dependence of the number of dechanneled protons on the bending angle was excellently fitted by the Gompertz type dechanneling function.
Energy loss distributions of relativistic protons axially channeled in a bent silicon crystal
Stojanov, Nace, E-mail: nacestoj@pmf.ukim.mk [Institute of Physics, Faculty of Natural Sciences and Mathematics, Sts. Cyril and Methodius University, P.O. Box 162, 1000 Skopje (Macedonia, The Former Yugoslav Republic of); Petrović, Srdjan; Nešković, Nebojša [Laboratory of Physics (010), Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia)
2013-05-01
A detailed study of the energy loss distributions of the relativistic protons axially channeled in the bent < 100 > Si crystals is presented in this work. The bending angle was varied from 0 to 20 μrad, while the crystal thickness was equal to 1 mm. The proton energy was chosen to be 7 TeV in accordance with the Large Hadron Collider (LHC) project, at the European Organization for Nuclear Research (CERN), in Geneva, Switzerland. The energy loss distributions of the channeled protons were generated using the numerical solution of the proton equations of motion in the transverse plane and the computer simulation method. An accurate energy loss model was used, which takes into account the trajectory dependence of the energy loss of protons during their motion through the crystal channels. Further, the dispersion of the proton’s scattering angle caused by its collisions with the electrons of the crystal and the divergence of the proton beam were taken into account. The calculated dependence of the number of dechanneled protons on the bending angle was excellently fitted by the Gompertz type dechanneling function.
Zhong, Yang; Yang, Chun-Bin; Cai, Xu; Feng, Sheng-Qin
2016-08-01
It has been proposed that electric fields may lead to chiral separation in quark-gluon plasma (QGP). This is called the chiral electric separation effect. The strong electromagnetic field and the QCD vacuum can both be completely produced in off-central nuclear-nuclear collision. We use the Woods-Saxon nucleon distribution to calculate the electric field distributions of off-central collisions. The chiral electric field spatial distribution at Relativistic Heavy-Ion Collider (RHIC) and Large Hadron Collider (LHC) energy regions are systematically studied in this paper. The dependence of the electric field produced by the thermal quark in the central position with different impact parameters on the proper time with different collision energies in the RHIC and LHC energy regions are studied in this paper. Supported by National Natural Science Foundation of China (11375069, 11435054, 11075061, 11221504) and Key Laboratory Foundation of Quark and Lepton Physics (Hua-Zhong Normal University)(QLPL2014P01)
Deng-Fan Potential for Relativistic Spinless Particles -- an Ansatz Solution
H. Hassanabadi; B.H. Yazarloo; S. Zarrinkamar; H. Rahimov
2012-01-01
Deng-Fan potential originally appeared many years ago as an attractive proposition for molecular systems. On the contrary to the ground state of one-dimensional Schr6dinger equation, this potential fails to admit exact analytical solutions for arbitrary quantum number in both relativistic and nonrelativistic regime. Because of this complexity, there exists only few papers, which discuss this interesting problem. Here, using an elegant ansatz, we have calculated the system spectra as well as the eigenfunctions in the general case of unequal vector and scalar potentials under Klein-Gordon equation.
Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandin, A. V.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, J. H.; Chen, H. F.; Cheng, J.; Cherney, M.; Christie, W.; Codrington, M. J. M.; Contin, G.; Crawford, H. J.; Cui, X.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Filip, P.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, X.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Klein, S. R.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, Z. M.; Li, X.; Li, W.; Li, Y.; Li, X.; Li, C.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, R. M.; Ma, Y. G.; Magdy, N.; Mahapatra, D. P.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D. L.; Page, B. S.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Simko, M.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solanki, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B. J.; Sun, X. M.; Sun, Z.; Sun, Y.; Sun, X.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Takahashi, J.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A. N.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, H.; Wang, F.; Wang, G.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, N.; Xu, Z.; Xu, H.; Xu, Y.; Xu, Q. H.; Yan, W.; Yang, Y.; Yang, C.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, X. P.; Zhang, Z. P.; Zhang, J. B.; Zhang, J. L.; Zhang, Y.; Zhang, S.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, Y. H.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration
2016-08-01
Balance functions have been measured in terms of relative pseudorapidity (Δ η ) for charged particle pairs at the BNL Relativistic Heavy Ion Collider from Au + Au collisions at √{sNN}=7.7 GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the CERN Large Hadron Collider from Pb + Pb collisions at √{sNN}=2.76 TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark gluon plasma (QGP). The narrowing of the balance function in central collisions at √{sNN}=7.7 GeV implies that a QGP is still being created at this relatively low energy.
Nemchik, J.; Petráček, V.; Potashnikova, I. K.; Šumbera, M.
2008-08-01
We study a strong suppression of the relative production rate (d-Au)/(p-p) for inclusive high-pT hadrons of different species at large forward rapidities (large Feynman xF). The model predictions calculated in the light-cone dipole approach are in a good agreement with the recent measurements by the BRAHMS and STAR Collaborations at the BNL Relativistic Heavy Ion Collider. We predict a similar suppression at large pT and large xF also at lower energies, where no effect of coherence is possible. This allows us to exclude the saturation models or the models based on Color Glass Condensate from interpretation of nuclear effects.
Pareja, M J
2004-01-01
For general relativistic equilibrium stellar models (stationary axisymmetric asymptotically flat and convection-free) with differential rotation, it is shown that for a wide class of rotation laws the distribution of angular velocity of the fluid has a sign, say "positive", and then both the dragging rate and the angular momentum density are positive. In addition, the "mean value" (with respect to an intrinsic density) of the dragging rate is shown to be less than the mean value of the fluid angular velocity (in full general, without having to restrict the rotation law, nor the uniformity in sign of the fluid angular velocity); this inequality yields the positivity and an upper bound of the total rotational energy.
Kagan, Daniel; Piran, Tsvi
2016-01-01
The maximum synchrotron burnoff limit of 160 MeV represents a fundamental limit to radiation resulting from electromagnetic particle acceleration in one-zone ideal plasmas. In magnetic reconnection, however, particle acceleration and radiation are decoupled because the electric field is larger than the magnetic field in the diffusion region. We carry out two-dimensional particle-in-cell simulations to determine the extent to which magnetic reconnection can produce synchrotron radiation above the burnoff limit. We use the test particle comparison (TPC) method to isolate the effects of cooling by comparing the trajectories and acceleration efficiencies of test particles incident on such a reconnection region with and without cooling them. We find that the cooled and uncooled particle trajectories are typically similar during acceleration in the reconnection region, and derive an effective limit on particle acceleration that is inversely proportional to the average magnetic field experienced by the particle duri...
Pareja, M J
2003-01-01
For relativistic stars rotating slowly and differentially with a positive angular velocity, some properties in relation to the positiveness of the rate of rotational dragging and of the angular momentum density are derived. Also, a new proof for the bounds on the rotational mass-energy is given.
Toyota, Koudai; Son, Sang-Kil; Santra, Robin
2017-04-01
In this paper, we theoretically study x-ray multiphoton ionization dynamics of heavy atoms taking into account relativistic and resonance effects. When an atom is exposed to an intense x-ray pulse generated by an x-ray free-electron laser (XFEL), it is ionized to a highly charged ion via a sequence of single-photon ionization and accompanying relaxation processes, and its final charge state is limited by the last ionic state that can be ionized by a single-photon ionization. If x-ray multiphoton ionization involves deep inner-shell electrons in heavy atoms, energy shifts by relativistic effects play an important role in ionization dynamics, as pointed out in Phys. Rev. Lett. 110, 173005 (2013), 10.1103/PhysRevLett.110.173005. On the other hand, if the x-ray beam has a broad energy bandwidth, the high-intensity x-ray pulse can drive resonant photoexcitations for a broad range of ionic states and ionize even beyond the direct one-photon ionization limit, as first proposed in Nat. Photon. 6, 858 (2012), 10.1038/nphoton.2012.261. To investigate both relativistic and resonance effects, we extend the xatom toolkit to incorporate relativistic energy corrections and resonant excitations in x-ray multiphoton ionization dynamics calculations. Charge-state distributions are calculated for Xe atoms interacting with intense XFEL pulses at a photon energy of 1.5 keV and 5.5 keV, respectively. For both photon energies, we demonstrate that the role of resonant excitations in ionization dynamics is altered due to significant shifts of orbital energy levels by relativistic effects. Therefore, it is necessary to take into account both effects to accurately simulate multiphoton multiple ionization dynamics at high x-ray intensity.
Spin, localization and uncertainty of relativistic fermions
Céleri, Lucas C; Terno, Daniel R
2016-01-01
We describe relations between several relativistic spin observables and derive a Lorentz-invariant characteristic of a reduced spin density matrix. A relativistic position operator that satisfies all the properties of its non-relativistic analogue does not exist. Instead we propose two causality-preserving positive operator-valued measures (POVM) that are based on projections onto one-particle and antiparticle spaces, and on the normalized energy density. They predict identical expectation values for position. The variances differ by less than a quarter of the squared de Broglie wavelength and coincide in the non-relativistic limit. Since the resulting statistical moment operators are not canonical conjugates of momentum, the Heisenberg uncertainty relations need not hold. Indeed, the energy density POVM leads to a lower uncertainty. We reformulate the standard equations of the spin dynamics by explicitly considering the charge-independent acceleration, allowing a consistent treatment of backreaction and incl...
Energy deposition of quasi-two temperature relativistic electrons in fast-shock ignition scenario
Ghasemi, Seyed Abolfazl; Farahbod, Amir Hossein
2016-10-01
Previous calculations from Solodov et al. (2008) indicate that classical stopping and scattering dominate electrons energy deposition and transport when the electrons reach the dense plasma in FSI inertial confinement fusion concept [1]. Our calculations show that, by using quasi- two temperature electrons energy distribution function [2] in comparison with exponential [3] or monoenergetic distribution function and also increasing fast electrons energy to about 7 MeV, the ratio of beam blooming to straggling definitely decreases. Our analytical analysis shows that for fuel mass more than 1 mg and for fast ignitor wavelength λif > 0.53 μ m, straggling and beam blooming increases. Meanwhile, by reducing fast ignitor wavelength from 0.53 to 0.35 micron, and for fuel mass about 2 mg, electron penetration into the dense fuel slightly increases. Therefore, reduction of scattering (blooming and straggling) of electrons and enhancement of electron penetration into the dense fuel, can be obtained in relativistic regime with high energy fast electrons of the order of 5 Mev and more. Such derivations can be used in theoretical studies of the ignition conditions and PIC simulations of the electron transport in fast ignition scenario.
Belich, H.; Bakke, K.
2016-03-01
The behavior of a relativistic scalar particle subject to a scalar potential under the effects of the violation of the Lorentz symmetry in the cosmic string space-time is discussed. It is considered two possible scenarios of the Lorentz symmetry breaking in the CPT-even gauge sector of the Standard Model Extension defined by a tensor (KF)μναβ. Then, by introducing a scalar potential as a modification of the mass term of the Klein-Gordon equation, it is shown that the Klein-Gordon equation in the cosmic string space-time is modified by the effects of the Lorentz symmetry violation backgrounds and bound state solution to the Klein-Gordon equation can be obtained.
Photon emission by ultra-relativistic positrons in crystalline undulators: the high-energy regime
Krause, W; Solov'yov, A V; Greiner, W
2015-01-01
This paper discusses the undulator radiation emitted by high-energy positrons during planar channeling in periodically bent crystals. We demonstrate that the construction of the undulator for positrons with energies of 10 GeV and above is only possible if one takes into account the radiative energy losses. The frequency of the undulator radiation depends on the energy of the particle. Thus the decrease of the particle's energy during the passage of the crystal should result in the destruction of the undulator radiation regime. However, we demonstrate that it is possible to avoid the destructive influence of the radiative losses on the frequency of the undulator radiation by the appropriate variation of the shape of the crystal channels. We also discuss a method by which, to our mind, it would be possible to prepare the crystal with the desired properties of its channels.
Fast magnetic energy dissipation in relativistic plasma induced by high order laser modes
Y.J.Gu; Q.Yu; O.Klimo; T.Zh.Esirkepov; S.V.Bulanov; S.Weber; G.Korn
2016-01-01
Fast magnetic field annihilation in a collisionless plasma is induced by using TEM(1,0) laser pulse. The magnetic quadrupole structure formation, expansion and annihilation stages are demonstrated with 2.5-dimensional particle-in-cell simulations. The magnetic field energy is converted to the electric field and accelerate the particles inside the annihilation plane. A bunch of high energy electrons moving backwards is detected in the current sheet. The strong displacement current is the dominant contribution which induces the longitudinal inductive electric field.
Savukov, I.; Safronova, U. I.; Safronova, M. S.
2015-11-01
Excitation energies, term designations, g factors, transition rates, and lifetimes of U2 + are determined using a relativistic configuration interaction (CI) + linearized-coupled-cluster (LCC) approach. The CI-LCC energies are compared with CI + many-body-perturbation-theory (MBPT) and available experimental energies. Close agreement has been found with experiment, within hundreds of cm-1. In addition, lifetimes of higher levels have been calculated for comparison with three experimentally measured lifetimes, and close agreement has been found within the experimental error. CI-LCC calculations constitute a benchmark test of the CI + all-order method in complex relativistic systems such as actinides and their ions with many valence electrons. The theory yields many energy levels, g factors, transition rates, and lifetimes of U2 + that are not available from experiment. The theory can be applied to other multivalence atoms and ions, which would be of interest to many applications.
Initial energy density of quark-gluon plasma in relativistic heavy-ion collisions
Wong, C.Y.
1984-01-01
Recently, there has been considerable interest in the central rapidity region of highly relativistic heavy-ion collisions. Such an interest stems from the possibility of creating hadron matter of high energy density which may exceed the critical energy density for a phase transition between ordinary confined matter and the unconfined quark-gluon plasma. The experimental searches and identification of the quark-gluon plasma may provide a new insight into the question of quark confinement. The estimate of the initial energy density is quite uncertain. The initial energy density is nonetheless an important physical quantity. It is one of the factors which determines whether the produced matter can undergo phase transition or not. The energy density has been estimated previously by using the color neutralization model of Brodsky et al. However, the color neutralization model gives a central rapidity multiplicity in heavy-ion collision too low by a factor of two. For this reason, we wish to obtain a better estimate of the energy density (in the central rapidity region). As is well known, a simple Glauber-type multiple collision model can reproduce the total multiplicity and multiplicity plateau near the central rapidity region to within 30%. The simple multiple collision model has an approximate validity as a gross description of the reaction process. We shall adopt a semiempirical approach. Using the multiple collision model and the thickness function of Glauber, we obtain analytical functional form for all the quantities in question. A single parameter, r/sub rms/, is adjusted to fit the experimental central rapidity multiplicity data. The semi-empirical results provide a useful tool to extrapolate to the unknown central rapidity region of heavy-ion collisions.
Horwitz, L. P.
2015-05-01
The most recent meeting took place at the University of Connecticut, Storrs, on June 9-13, 2014. This meeting forms the basis for the Proceedings that are recorded in this issue of the Journal of Physics: Conference Series. Along with the work of some of the founding members of the Association, we were fortunate to have lecturers from application areas that provided strong challenges for further developments in quantum field theory, cosmological problems, and in the dynamics of systems subject to accelerations and the effects of general relativity. Topics treated in this issue include studies of the dark matter problem, rotation curves, and, in particular, for the (relatively accessible) Milky Way galaxy, compact stellar objects, a composite particle model, and the properties of a conformally invariant theory with spontaneous symmetry breaking. The Stueckelberg theory is further investigated for its properties in producing bremsstrahlung and pair production and apparent superluminal effects, and, as mentioned above, the implications of low energy nuclear reactions for such off-shell theories. Other "proper time" theories are investigated as well, and a study of the clock synchronization problem is presented. A mathematical study of to quantum groupo associated with the Toda lattice and its implications for quantum field theory, as well as a phenomenological discussion of supernova mechanics as well as a semiclassical discussion of electron spin and the question of the compatibility of special relativity and the quantum theory. A careful analysis of the covariant Aharonov-Bohm effect is given as well. The quantization of massless fields and the relation to the Maxwell theory is also discussed. We wish to thank the participants who contributed very much through their lectures, personal discussions, and these papers, to the advancement of the subject and our understanding.
ZHANG Peng-Fei; RUAN Tu-Nan
2001-01-01
A systematic theory on the appropriate spin operators for the relativistic states is developed. For a massive relativistic particle with arbitrary nonzero spin, the spin operator should be replaced with the relativistic one, which is called in this paper as moving spin. Further the concept of moving spin is discussed in the quantum field theory. A new is constructed. It is shown that, in virtue of the two operators, problems in quantum field concerned spin can be neatly settled.
iVPIC: A low-dispersion, energy-conserving relativistic PIC solver for LPI simulations
Chacon, Luis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-06-07
We have developed a novel low-dispersion, exactly energy-conserving PIC algorithm for the relativistic Vlasov-Maxwell system. The approach features an exact energy conservation theorem while preserving the favorable performance and numerical dispersion properties of explicit PIC. The new algorithm has the potential to enable much longer laser-plasma-interaction (LPI) simulations than are currently possible.
Particle Production at RHIC and LHC Energies
Tawfik, A; Shalaby, A G
2012-01-01
The production of different particle species is recently measured in $Pb-Pb$ collisions by the ALICE experiment at $\\sqrt{s}=7 $TeV. This motivates the use of various bosons and baryons measured at lower center-of-mass energies in comparing their ratios to the hadron resonance (HRG) gas model and PYTHIA event generator. It is found that the particle-to-antiparticle ratios are perfectly reproduce by means of HRG and PYTHIA at RHIC and LHC energies. The kaon-to-pion and proton-to-pion ratios are entirely overestimated by the HRG model. The PYTHIA event generator obviously underestimates the kaon-to-pion ratio and simultaneously reproduces the proton-to-pion ratio, almost perfectly, especially at LHC energy. While matter-to-antimatter and non-strange abundances are partly in line with predictions from the HRG model, it is found in the ALICE experiment that the measured baryon ratios are suppressed by a factor of $\\sim1.5$. The strange abundances are overestimated in the HRG model.
On a Singular Solution in Higgs Field (3) - Relativistical Energy Flow towards Higgs boson
Kitazawa, Kazuyoshi
2012-03-01
The mass of SM Higgs boson (H^0) is re-examined under fluid mechanical consideration of micro (femt-scale) Reynolds number in Higgs boson sea for the process of Higgs mechanism. In this analysis, two gauge particles (W and Z bosons) are adopted as representatives to describe the process through their each mass acquisition. The mass value of fluid mechanical H^0 (f.m.-H^0) is calculated relativistically at 128.6 GeV/c^2, which is a little (6.6 per-cent) larger than our mass value of the asymptotic solution (theoretical mass: 120.611 GeV/c^2) of Higgs field.footnotetextK. Kitazawa, DPF MEETING 2011: 166. This difference of mass value shows that there would be some extent of excess in sectional area's evaluation for f.m.-H^0. Because, in this numerical calculation we assumed that f.m.-H^0 in Higgs boson sea is sphere. While theoretical mass of H^0 had a shape of truncated-Octahedron which inscribes to the sectional circle of f.m.-H^0. So we may reduce this excess of mass since the drag force against the flow, which is proportional to sectional area of f.m.-H^0, corresponds to acquired mass by Higgs mechanism. It is noteworthy that theoretical mass above is almost at center of the most like range of latest LHC's result for SM Higgs boson mass.
Zheng, Chun-Yang; Zhu, Shao-Ping; He, Xian-Tu
2002-07-01
The quasi-static magnetic fields created in the interaction of relativistic laser pulses with under-dense plasmas have been investigated by three-dimensional particle-in-cell simulation. The relativistic ponderomotive force can drive an intense electron current in the laser propagation direction, which is responsible for the generation of a helical magnetic field. The axial magnetic field results from a difference beat of wave-wave, which drives a solenoidal current. In particular, the physical significance of the kinetic model for the generation of the axial magnetic field is discussed.
郑春阳; 朱少平; 贺贤土
2002-01-01
The quasi-static magnetic fields created in the interaction of relativistic laser pulses with under-dense plasmashave been investigated by three-dimensional particle-in-cell simulation. The relativistic ponderomotive force candrive an intense electron current in the laser propagation direction, which is responsible for the generation ofa helical magnetic field. The axial magnetic field results from a difference beat of wave-wave, which drives asolenoidal current. In particular, the physical significance of the kinetic model for the generation of the axialmagnetic field is discussed.
The central engine of GRB 130831A and the energy breakdown of a relativistic explosion
De Pasquale, M.; Oates, S. R.; Racusin, J. L.; Kann, D. A.; Zhang, B.; Pozanenko, A.; Volnova, A. A.; Trotter, A.; Frank, N.; Cucchiara, A.; Troja, E.; Sbarufatti, B.; Butler, N. R.; Schulze, S.; Cano, Z.; Page, M. J.; Castro-Tirado, A. J.; Gorosabel, J.; Lien, A.; Fox, O.; Littlejohns, O.; Bloom, J. S.; Prochaska, J. X.; de Diego, J. A.; Gonzalez, J.; Richer, M. G.; Román-Zúñiga, C.; Watson, A. M.; Gehrels, N.; Moseley, H.; Kutyrev, A.; Zane, S.; Hoette, V.; Russell, R. R.; Rumyantsev, V.; Klunko, E.; Burkhonov, O.; Breeveld, A. A.; Reichart, D. E.; Haislip, J. B.
2016-01-01
Gamma-ray bursts (GRBs) are the most luminous explosions in the Universe, yet the nature and physical properties of their energy sources are far from understood. Very important clues, however, can be inferred by studying the afterglows of these events. We present optical and X-ray observations of GRB 130831A obtained by Swift, Chandra, Skynet, Reionization And Transients Infra-Red camera, Maidanak, International Scientific Optical-Observation Network, Nordic Optical Telescope, Liverpool Telescope and Gran Telescopio Canarias. This burst shows a steep drop in the X-ray light curve at ≃105 s after the trigger, with a power-law decay index of α ˜ 6. Such a rare behaviour cannot be explained by the standard forward shock (FS) model and indicates that the emission, up to the fast decay at 105 s, must be of `internal origin', produced by a dissipation process within an ultrarelativistic outflow. We propose that the source of such an outflow, which must produce the X-ray flux for ≃1 d in the cosmological rest frame, is a newly born magnetar or black hole. After the drop, the faint X-ray afterglow continues with a much shallower decay. The optical emission, on the other hand, shows no break across the X-ray steep decrease, and the late-time decays of both the X-ray and optical are consistent. Using both the X-ray and optical data, we show that the emission after ≃105 s can be explained well by the FS model. We model our data to derive the kinetic energy of the ejecta and thus measure the efficiency of the central engine of a GRB with emission of internal origin visible for a long time. Furthermore, we break down the energy budget of this GRB into the prompt emission, the late internal dissipation, the kinetic energy of the relativistic ejecta, and compare it with the energy of the associated supernova, SN 2013 fu.
When do particle ratios freeze out in relativistic heavy ion collisions?
Humanic, Thomas; Bellwied, Rene
1999-10-01
The systematics of CERN SPS data for transverse mass distributions have been shown to imply that thermal equilibrium is achieved at freeze out in these collisions. This conclusion is based on the observation that for p+p, S+S, and Pb+Pb collisions freeze out occurs at a single temperature for all particle species measured if one assumes a certain uniform expansion velocity after hadronization for each colliding system [1]. A recent final- state rescattering calculation for SPS Pb+Pb collisions has shown that these systematics can be described as a consequence of particle rescattering where the system is assumed initially (i.e. at hadronization) to have a common temperature for all particles and no initial expansion velocity [2]. In addition to kinetic observables, it is equally interesting to investigate the time dependence of particle abundances through particle ratios in such a calculation. Two questions immediately arise: 1) is chemical equilibrium established in these collisions, and 2) when does chemical freeze out occur with respect to thermal freeze out for different particle ratios? How rescattering influences particle ratios is clearly of interest if one would like to deduce information about the hadronization stage of the collision from particle ratios measured at freeze out. For the present work we will show results for strange and non-strange particle ratios within the context of a version of the dynamic transport code used in Ref. [2]. [1] NA44 colaboration, I.G. Bearden et al., Phys. Rev. Lett. 78,2080(1997), [2] T. J. Humanic, Phys. Rev. C 57,866(1998)
Cao, Shanshan; Bass, Steffen A
2015-01-01
We construct a theoretical framework to describe the evolution of heavy flavors produced in relativistic heavy-ion collisions. The in-medium energy loss of heavy quarks is described using our modified Langevin equation that incorporates both quasi-elastic scatterings and the medium-induced gluon radiation. The space-time profiles of the fireball is described by a (2+1)-dimensional hydrodynamics simulation. A hybrid model of fragmentation and coalescence is utilized for heavy quark hadronization, after which the produced heavy mesons together with the soft hadrons produced from the bulk QGP are fed into the hadron cascade UrQMD model to simulate the subsequent hadronic interactions. We find that the medium-induced gluon radiation contributes significantly to heavy quark energy loss at high $p_\\mathrm{T}$; heavy-light quark coalescence enhances heavy meson production at intermediate $p_\\mathrm{T}$; and scatterings inside the hadron gas further suppress the $D$ meson $R_\\mathrm{AA}$ at large $p_\\mathrm{T}$ and e...
Zapp, Edward Neal
Simulation of energetic, colliding nuclear systems at energies between 100 AMeV and 5 AGeV has utility in fields as diverse as the design and construction of fundamental particle physics experiments, patient treatment by radiation exposure, and in the protection of astronaut crews from the risks of exposure to natural radiation sources during spaceflight. Descriptions of these colliding systems which are derived from theoretical principles are necessary in order to provide confidence in describing systems outside the scope of existing data, which is sparse. The system size and velocity dictate descriptions which include both special relativistic and quantum effects, and the currently incomplete state of understanding with respect to the basic processes at work within nuclear matter dictate that any description will exist at some level of approximation. Models commonly found in the literature employ approximations to theory which lead to simulation results which demonstrate departure from fundamental physical principles, most notably conservation of system energy. The HMD (Hamiltonian Molecular Dynamics) mode is developed as a phase-space description of colliding nuclear system on the level of hadrons, inclusive of the necessary quantum and relativistic elements. Evaluation of model simulations shows that the HMD model shows the necessary conservations throughout system simulation. HMD model predictions are compared to both the RQMD (Relativistic Quantum Molecular Dynamics) and JQMD (Jaeri-Quantum Molecular Dynamics) codes, both commonly employed for the purpose of simulating nucleus-nucleus collisions. Comparison is also provided between all three codes and measurement. The HMD model is shown to perform well in light of both measurement and model calculation, while providing for a physically self-consistent description of the system throughout.
Augusto, C R A; de Oliveira, M N; Shigueoka, H; Nepomuceno, A A; Fauth, A C
2015-01-01
Far away from any sunspot, a bright flare erupted on November 1st, 2014, with onset at 4:44 UT and a duration of around three hours, causing a C2.7-class flare. The blast was associated with the sudden disappearance of a large dark solar filament. The rest of the filament flew out into space, forming the core of a massive CME. Despite the location of the explosion over the sun's southeastern region (near the eastern edge of the sun) not be geoeffective, a radiation storm, that is, solar energetic particles (SEP) started to reach the Earth around 14:00 UT, reaching the condition of an S1 (minor) radiation storm level on Nov. 2th. In coincidence with onset of the S1 radiation storm (SEP above 5 MeV), the Tupi telescopes located at $22^090'$S; $43^020'$W, within the South Atlantic Anomaly (SAA) detected a muon enhancement caused by relativistic protons from this solar blast. In addition an increase in the particle intensity was found also at South Pole neutron monitor. This means that there was a transverse prop...
Wave-induced loss of ultra-relativistic electrons in the Van Allen radiation belts
Shprits, Yuri Y.; Drozdov, Alexander Y.; Spasojevic, Maria; Kellerman, Adam C.; Usanova, Maria E.; Engebretson, Mark J.; Agapitov, Oleksiy V.; Zhelavskaya, Irina S.; Raita, Tero J.; Spence, Harlan E.; Baker, Daniel N.; Zhu, Hui; Aseev, Nikita A.
2016-01-01
The dipole configuration of the Earth's magnetic field allows for the trapping of highly energetic particles, which form the radiation belts. Although significant advances have been made in understanding the acceleration mechanisms in the radiation belts, the loss processes remain poorly understood. Unique observations on 17 January 2013 provide detailed information throughout the belts on the energy spectrum and pitch angle (angle between the velocity of a particle and the magnetic field) distribution of electrons up to ultra-relativistic energies. Here we show that although relativistic electrons are enhanced, ultra-relativistic electrons become depleted and distributions of particles show very clear telltale signatures of electromagnetic ion cyclotron wave-induced loss. Comparisons between observations and modelling of the evolution of the electron flux and pitch angle show that electromagnetic ion cyclotron waves provide the dominant loss mechanism at ultra-relativistic energies and produce a profound dropout of the ultra-relativistic radiation belt fluxes. PMID:27678050
Wave-induced loss of ultra-relativistic electrons in the Van Allen radiation belts.
Shprits, Yuri Y; Drozdov, Alexander Y; Spasojevic, Maria; Kellerman, Adam C; Usanova, Maria E; Engebretson, Mark J; Agapitov, Oleksiy V; Zhelavskaya, Irina S; Raita, Tero J; Spence, Harlan E; Baker, Daniel N; Zhu, Hui; Aseev, Nikita A
2016-09-28
The dipole configuration of the Earth's magnetic field allows for the trapping of highly energetic particles, which form the radiation belts. Although significant advances have been made in understanding the acceleration mechanisms in the radiation belts, the loss processes remain poorly understood. Unique observations on 17 January 2013 provide detailed information throughout the belts on the energy spectrum and pitch angle (angle between the velocity of a particle and the magnetic field) distribution of electrons up to ultra-relativistic energies. Here we show that although relativistic electrons are enhanced, ultra-relativistic electrons become depleted and distributions of particles show very clear telltale signatures of electromagnetic ion cyclotron wave-induced loss. Comparisons between observations and modelling of the evolution of the electron flux and pitch angle show that electromagnetic ion cyclotron waves provide the dominant loss mechanism at ultra-relativistic energies and produce a profound dropout of the ultra-relativistic radiation belt fluxes.
Wave-induced loss of ultra-relativistic electrons in the Van Allen radiation belts
Shprits, Yuri Y.; Drozdov, Alexander Y.; Spasojevic, Maria; Kellerman, Adam C.; Usanova, Maria E.; Engebretson, Mark J.; Agapitov, Oleksiy V.; Zhelavskaya, Irina S.; Raita, Tero J.; Spence, Harlan E.; Baker, Daniel N.; Zhu, Hui; Aseev, Nikita A.
2016-09-01
The dipole configuration of the Earth's magnetic field allows for the trapping of highly energetic particles, which form the radiation belts. Although significant advances have been made in understanding the acceleration mechanisms in the radiation belts, the loss processes remain poorly understood. Unique observations on 17 January 2013 provide detailed information throughout the belts on the energy spectrum and pitch angle (angle between the velocity of a particle and the magnetic field) distribution of electrons up to ultra-relativistic energies. Here we show that although relativistic electrons are enhanced, ultra-relativistic electrons become depleted and distributions of particles show very clear telltale signatures of electromagnetic ion cyclotron wave-induced loss. Comparisons between observations and modelling of the evolution of the electron flux and pitch angle show that electromagnetic ion cyclotron waves provide the dominant loss mechanism at ultra-relativistic energies and produce a profound dropout of the ultra-relativistic radiation belt fluxes.
Applying Relativistic Reconnection to Blazar Jets
Nalewajko, Krzysztof
2016-01-01
Rapid and luminous flares of non-thermal radiation observed in blazars require an efficient mechanism of energy dissipation and particle acceleration in relativistic active galactic nuclei (AGN) jets. Particle acceleration in relativistic magnetic reconnection is being actively studied by kinetic numerical simulations. Relativistic reconnection produces hard power-law electron energy distributions N(gamma) = N_0 gamma^(-p) exp(-gamma/gamma_max) with index p -> 1 and exponential cut-off Lorentz factor gamma_max ~ sigma in the limit of magnetization sigma = B^2/(4 pi w) >> 1 (where w is the relativistic enthalpy density). Reconnection in electron-proton plasma can additionally boost gamma_max by the mass ratio m_p/m_e. Hence, in order to accelerate particles to gamma_max ~ 10^6 in the case of BL Lacs, reconnection should proceed in plasma of very high magnetization sigma_max >~ 10^3. On the other hand, moderate mean jet magnetization values are required for magnetic bulk acceleration of relativistic jets, sigma...
Enhanced stopping of macro-particles in particle-in-cell simulations
May, J; Tonge, J; Ellis, I; Mori, W. B.; Fiuza, F.; Fonseca, R. A.; Silva,L. O.; Ren, C.
2014-01-01
WOS:000337107200042 (Nº de Acesso Web of Science) We derive an equation for energy transfer from relativistic charged particles to a cold background plasma appropriate for finite-size particles that are used in particle-in-cell simulation codes. Expressions for one-, two-, and three-dimensional particles are presented, with special attention given to the two-dimensional case. This energy transfer is due to the electric field of the wake set up in the background plasma by the relativistic p...
Asymptotic domination of cold relativistic MHD winds by kinetic energy flux
Begelman, Mitchell C.; Li, Zhi-Yun
1994-01-01
We study the conditions which lead to the conversion of most Poynting flux into kinetic energy flux in cold, relativistic hydromagnetic winds. It is shown that plasma acceleration along a precisely radial flow is extremely inefficient due to the near cancellation of the toroidal magnetic pressure and tension forces. However, if the flux tubes in a flow diverge even slightly faster than radially, the fast magnetosonic point moves inward from infinity to a few times the light cylinder radius. Once the flow becomes supermagnetosonic, further divergence of the flux tubes beyond the fast point can accelerate the flow via the 'magnetic nozzle' effect, thereby further converting Poynting flux to kinetic energy flux. We show that the Grad-Shafranov equation admits a generic family of kinetic energy-dominated asymptotic wind solutions with finite total magnetic flux. The Poynting flux in these solutions vanishes logarithmically with distance. The way in which the flux surfaces are nested within the flow depends only on the ratio of angular velocity to poliodal 4-velocity as a function of magnetic flux. Radial variations in flow structure can be expressed in terms of a pressure boundary condition on the outermost flux surface, provided that no external toriodal field surrounds the flow. For a special case, we show explicitly how the flux surfaces merge gradually to their asymptotes. For flows confined by an external medium of pressure decreasing to zero at infinity we show that, depending on how fast the ambient pressure declines, the final flow state could be either a collimated jet or a wind that fills the entire space. We discuss the astrophysical implications of our results for jets from active galactic nuclei and for free pulsar winds such as that believed to power the Crab Nebula.
Magnetic field evolution in relativistic unmagnetized collisionless shocks
Keshet, Uri; Spitkovsky, Anatoly; Waxman, Eli
2008-01-01
We study relativistic unmagnetized collisionless shocks using unprecedentedly large particle-in-cell simulations of two-dimensional pair plasma. High energy particles accelerated by the shock are found to drive magnetic field evolution on a time scale >10^4 plasma times. Progressively stronger magnetic fields are generated on larger scales in a growing region around the shock. Shock-generated magnetic fields and accelerated particles carry >1% and >10% of the downstream energy flux respectively. Our results suggest limits on the magnetization of relativistic astrophysical flows.
On a Probabilistic Interpretation of Relativistic Quantum Mechanics
Gorobey, Natalia; Lukyanenko, Inna
2010-01-01
A probabilistic interpretation of one-particle relativistic quantum mechanics is proposed. Quantum Action Principle formulated earlier is used for to make the dynamics of the Minkowsky time variable of a particle to be classical. After that, quantum dynamics of a particle in the 3D space obtains the ordinary probabilistic interpretation. In addition, the classical dynamics of the Minkowsky time variable may serve as a tool for "observation" of the quantum dynamics of a particle. A relativistic analog of the hydrogen atom energy spectrum is obtained.
Magnetizabilities of relativistic hydrogenlike atoms in some arbitrary discrete energy eigenstates
Stefańska, Patrycja
2016-01-01
We present the results of numerical calculations of magnetizability ($\\chi$) of the relativistic one-electron atoms with a pointlike, spinless and motionless nuclei of charge $Ze$. Exploiting the analytical formula for $\\chi$ recently derived by us [P. Stefa{\\'n}ska, 2015], valid for an arbitrary discrete energy eigenstate, we have found the values of the magnetizability for the ground state and for the first and the second set of excited states (i.e.: $2s_{1/2}$, $2p_{1/2}$, $2p_{3/2}$, $3s_{1/2}$, $3p_{1/2}$, $3p_{3/2}$, $3d_{3/2}$, and $3d_{5/2}$) of the Dirac one-electron atom. The results for ions with the atomic number $1 \\leqslant Z \\leqslant 137$ are given in 14 tables. The comparison of the numerical values of magnetizabilities for the ground state and for each states belonging to the first set of excited states of selected hydrogenlike ions, obtained with the use of two different values of the fine-structure constant, i.e.: $\\alpha^{-1}=137.035 999 139$ (CODATA 2014) and $\\alpha^{-1}=137.035 999 074...
Very high energy emission as a probe of relativistic magnetic reconnection in pulsar winds
Mochol, Iwona
2015-01-01
The population of gamma-ray pulsars, including Crab observed in the TeV range, and Vela detected above 50 GeV, challenges existing models of pulsed high-energy emission. Such models should be universally applicable, yet they should account for spectral differences among the pulsars. We show that the gamma-ray emission of Crab and Vela can be explained by synchrotron radiation from the current sheet of a striped wind, expanding with a modest Lorentz factor $\\Gamma\\lesssim100$ in the Crab case, and $\\Gamma\\lesssim50$ in the Vela case. In the Crab spectrum a new synchrotron self-Compton component is expected to be detected by the upcoming experiment CTA. We suggest that the gamma-ray spectrum directly probes the physics of relativistic magnetic reconnection in the striped wind. In the most energetic pulsars, like Crab, with $\\dot{E}_{38}^{3/2}/P_{-2}\\gtrsim0.002$ (where $\\dot{E}$ is the spin down power, $P$ is the pulsar period, and $X=X_i\\times10^i$ in CGS units), reconnection proceeds in the radiative cooling ...
Nuclear matter fourth-order symmetry energy in relativistic mean field models
Cai, Bao-Jun
2011-01-01
Within the nonlinear relativistic mean field model, we derive the analytical expression of the nuclear matter fourth-order symmetry energy $E_{4}(\\rho)$. Our results show that the value of $E_{4}(\\rho)$ at normal nuclear matter density $\\rho_{0}$ is generally less than 1 MeV, confirming the empirical parabolic approximation to the equation of state for asymmetric nuclear matter at $\\rho_{0}$. On the other hand, we find that the $E_{4}(\\rho)$ may become nonnegligible at high densities. Furthermore, the analytical form of the $E_{4}(\\rho)$ provides the possibility to study the higher-order effects on the isobaric incompressibility of asymmetric nuclear matter, i.e., $K_{\\mathrm{sat}}(\\delta)=K_{0}+K_{\\mathrm{{sat},2}}\\delta ^{2}+K_{\\mathrm{{sat},4}}\\delta ^{4}+\\mathcal{O}(\\delta ^{6})$ where $\\delta =(\\rho_{n}-\\rho_{p})/\\rho $ is the isospin asymmetry, and we find that the value of $K_{\\mathrm{{sat},4}}$ is generally comparable with that of the $K_{\\mathrm{{sat},2}}$. In addition, we study the effects of the $E...
Balakin, Alexander B.; Popov, Vladimir A.
2017-04-01
In the framework of the Einstein-aether theory we consider a cosmological model, which describes the evolution of the unit dynamic vector field with activated rotational degree of freedom. We discuss exact solutions of the Einstein-aether theory, for which the space-time is of the Gödel-type, the velocity four-vector of the aether motion is characterized by a non-vanishing vorticity, thus the rotational vectorial modes can be associated with the source of the universe rotation. The main goal of our paper is to study the motion of test relativistic particles with a vectorial internal degree of freedom (spin or polarization), which is coupled to the unit dynamic vector field. The particles are considered as the test ones in the given space-time background of the Gödel-type the spin (polarization) coupling to the unit dynamic vector field is modeled using exact solutions of three types. The first exact solution describes the aether with arbitrary Jacobson's coupling constants; the second one relates to the case, when the Jacobson's constant responsible for the vorticity is vanishing; the third exact solution is obtained using three constraints for the coupling constants. The analysis of the exact expressions, which are obtained for the particle momentum and for the spin (polarization) four-vector components, shows that the interaction of the spin (polarization) with the unit vector field induces a rotation, which is additional to the geodesic precession of the spin (polarization) associated with the universe rotation as a whole.
Collective Flow in Heavy Ion Collisions at Low to Relativistic Energies
Lisa, M. A.
1997-04-01
Recently, the phenomenon of collective flow in heavy ion collisions has been the subject of intense study. First observed at the Bevalac more than a decade ago, flow is now recognized as a universal feature of heavy ion collisions at all bombarding energies. Recent developments in three identified forms of flow-- sidewards flow, radial flow, and squeeze-out-- will be reviewed. At low energies (EOS and FOPI collaborations have considerably extended the work begun by the Plastic Ball group; here, studies of the flow of nucleons, fragments, and pions lead to a better understanding of the Equation of State of nuclear matter, momentum dependent interactions, and pion shadowing. The squeeze-out effect at Bevalac energies may be the most sensitive form of flow to the equation of state. Recent studies suggest that squeeze-out may be considered as an azimuthal modulation of the radial flow. The E895 collaboration is continuing the flow excitation function of the EOS/FOPI groups for 2-10 A GeV bombarding energies, with the aim of increasing the sensitivity to Equation of State parameters, as well as searching for flow signatures of Quark Gluon Plasma creation. Sidewards flow at the highest AGS energy for Au beams(11 A GeV) has been reported by the E877 collaboration, which has correlated the effect with pion interferometry measurements to identify possible dynamical correlations in the collision. Finally, at the highest energies currently available, the NA49 collaboration has found sidewards flow at SPS energies (160 A GeV); preliminary comparisons to RQMD calculations indicate that the model reproduces the flow well. At all of these bombarding energies (over 3 orders of magnitude!), the particle spectra show a strong non-thermal component which has been identified as largely isotropic or "radial" flow. While the sidewards flow accounts for only ~5% of emitted particles' energy, roughly 30-50% of the energy of emitted particles is found in radial flow. Several groups are
Borovskiy, A. V. [Department of Computer Science and Cybernetics, Baikal State University of Economics and Law, 11 Lenin Street, Irkutsk 664003 (Russian Federation); Galkin, A. L. [Coherent and Nonlinear Optics Department, A.M. Prokhorov General Physics Institute of the RAS, 38 Vavilov Street, Moscow 119991 (Russian Federation); Department of Physics of MBF, Pirogov Russian National Research Medical University, 1 Ostrovitianov Street, Moscow 117997 (Russian Federation); Kalashnikov, M. P., E-mail: galkin@kapella.gpi.ru [Max-Born-Institute for Nonlinear Optics and Short-Time Spectroscopy, 2a Max-Born-Strasse, Berlin 12489 (Germany)
2015-04-15
The new method of calculating energy spectra of accelerated electrons, based on the parameterization by their initial coordinates, is proposed. The energy spectra of electrons accelerated by Gaussian ultra-short relativistic laser pulse at a selected angle to the axis of the optical system focusing the laser pulse in a low density gas are theoretically calculated. The two-peak structure of the electron energy spectrum is obtained. Discussed are the reasons for its appearance as well as an applicability of other models of the laser field.
Quantum heat engine in the relativistic limit: The case of a Dirac particle
Muñoz, Enrique; Peña, Francisco J.
2012-12-01
We studied the efficiency of two different schemes for a quantum heat engine, by considering a single Dirac particle trapped in an infinite one-dimensional potential well as the “working substance.” The first scheme is a cycle, composed of two adiabatic and two isoenergetic reversible trajectories in configuration space. The trajectories are driven by a quasistatic deformation of the potential well due to an external applied force. The second scheme is a variant of the former, where isoenergetic trajectories are replaced by isothermal ones, along which the system is in contact with macroscopic thermostats. This second scheme constitutes a quantum analog of the classical Carnot cycle. Our expressions, as obtained from the Dirac single-particle spectrum, converge in the nonrelativistic limit to some of the existing results in the literature for the Schrödinger spectrum.
Self-modulation instability of ultra-relativistic particle bunches with finite rise times
Vieira, J; Fang, Y; Mori, W B; Muggli, P; Silva, L O
2014-01-01
We study the evolution of the self-modulation instability using bunches with finite rise times. Using particle-in-cell simulations we show that unlike long bunches with sharp rise times, there are large variations of the wake amplitudes and wake phase velocity when bunches with finite rise times are used. These results show that use of bunches with sharp rise times is important to seed the self-modulation instability and to ensure stable acceleration regimes.
Distributed drift chamber design for rare particle detection in relativistic heavy ion collisions
Bellwied, R.; Bennett, M.J.; Bernardo, V.; Caines, H.; Christie, W.; Costa, S.; Crawford, H.J.; Cronqvist, M.; Debbe, R.; Dinnwiddie, R.; Engelage, J. E-mail: jmengelage@lbl.gov; Flores, I.; Fuzesy, R.; Greiner, L.; Hallman, T.; Hoffmann, G.; Huang, H.Z.; Jensen, P.; Judd, E.G.; Kainz, K.; Kaplan, M.; Kelly, S.; Lindstrom, P.J.; Llope, W.J.; LoCurto, G.; Longacre, R.; Milosevich, Z.; Mitchell, J.T.; Mitchell, J.W.; Mogavero, E.; Mutchler, G.; Paganis, S.; Platner, E.; Potenza, R.; Rotondo, F.; Russ, D.; Sakrejda, I.; Saulys, A.; Schambach, J.; Sheen, J.; Smirnoff, N.; Stokeley, C.; Tang, J.; Trattner, A.L.; Trentalange, S.; Visser, G.; Whitfield, J.P.; Witharm, F.; Witharm, R.; Wright, M
2002-06-11
This report describes a multi plane drift chamber that was designed and constructed to function as a topological detector for the BNL AGS E896 rare particle experiment. The chamber was optimized for good spatial resolution, two track separation, and a high uniform efficiency while operating in a 1.6 T magnetic field and subjected to long term exposure from a 11.6 GeV/nucleon beam of 10{sup 6} Au ions per second.
Distributed drift chamber design for rare particle detection in relativistic heavy ion collisions
Bellwied, R.; Bennett, M.J.; Bernardo, V.; Caines, H.; Christie, W.; Costa, S.; Crawford, H.J.; Cronqvist, M.; Debbe, R.; Dinnwiddie, R.; Engelage, J.; Flores, I.; Fuzesy, R.; Greiner, L.; Hallman, T.; Hoffmann, G.; Huang, H.Z.; Jensen, P.; Judd, E.G.; Kainz, K.; Kaplan, M.; Kelly, S.; Lindstrom, P.J; Llope, W.J.; LoCurto, G.; Longacre, R.; Milosevich, Z.; Mitchell, J.T.; Mitchell, J.W.; Mogavero, E.; Mutchler, G.; Paganis, S.; Platner, E.; Potenza, R.; Rotondo, F.; Russ, D.; Sakrejda, I.; Saulys, A.; Schambach, J.; Sheen, J.; Smirnoff, N.; Stokeley, C.; Tang, J.; Trattner, A.L.; Trentalange, S.; Visser, G.; Whitfield, J.P.; Witharm, F.; Witharm, R.; Wright, M.
2001-10-02
This report describes a multi-plane drift chamber that was designed and constructed to function as a topological detector for the BNL AGSE896 rare particle experiment. The chamber was optimized for good spatial resolution, two track separation, and a high uniform efficiency while operating in a 1.6 Tesla magnetic field and subjected to long term exposure from a 11.6 GeV/nucleon beam of 10**6 Au ions per second.
Relativistic Runaway Electrons
Breizman, Boris
2014-10-01
This talk covers recent developments in the theory of runaway electrons in a tokamak with an emphasis on highly relativistic electrons produced via the avalanche mechanism. The rapidly growing population of runaway electrons can quickly replace a large part of the initial current carried by the bulk plasma electrons. The magnetic energy associated with this current is typically much greater than the particle kinetic energy. The current of a highly relativistic runaway beam is insensitive to the particle energy, which separates the description of the runaway current evolution from the description of the runaway energy spectrum. A strongly anisotropic distribution of fast electrons is generally prone to high-frequency kinetic instabilities that may cause beneficial enhancement of runaway energy losses. The relevant instabilities are in the frequency range of whistler waves and electron plasma waves. The instability thresholds reported in earlier work have been revised considerably to reflect strong dependence of collisional damping on the wave frequency and the role of plasma non-uniformity, including radial trapping of the excited waves in the plasma. The talk also includes a discussion of enhanced scattering of the runaways as well as the combined effect of enhanced scattering and synchrotron radiation. A noteworthy feature of the avalanche-produced runaway current is a self-sustained regime of marginal criticality: the inductive electric field has to be close to its critical value (representing avalanche threshold) at every location where the runaway current density is finite, and the current density should vanish at any point where the electric field drops below its critical value. This nonlinear Ohm's law enables complete description of the evolving current profile. Work supported by the U.S. Department of Energy Contract No. DEFG02-04ER54742 and by ITER contract ITER-CT-12-4300000273. The views and opinions expressed herein do not necessarily reflect those of
Relativistic Guiding Center Equations
White, R. B. [PPPL; Gobbin, M. [Euratom-ENEA Association
2014-10-01
In toroidal fusion devices it is relatively easy that electrons achieve relativistic velocities, so to simulate runaway electrons and other high energy phenomena a nonrelativistic guiding center formalism is not sufficient. Relativistic guiding center equations including flute mode time dependent field perturbations are derived. The same variables as used in a previous nonrelativistic guiding center code are adopted, so that a straightforward modifications of those equations can produce a relativistic version.
Wieland, Volkmar; Niemiec, Jacek; Rafighi, Iman; Nishikawa, Ken-Ichi
2016-01-01
For parameters that are applicable to the conditions at young supernova remnants, we present results of 2D3V particle-in-cell simulations of a non-relativistic plasma shock with a large-scale perpendicular magnetic field inclined at 45-deg angle to the simulation plane to approximate 3D physics. We developed an improved clean setup that uses the collision of two plasma slabs with different density and velocity, leading to the development of two distinctive shocks and a contact discontinuity. The shock formation is mediated by Weibel-type filamentation instabilities that generate magnetic turbulence. Cyclic reformation is observed in both shocks with similar period, for which we note global variations on account of shock rippling and local variations arising from turbulent current filaments. The shock rippling occurs on spatial and temporal scales given by gyro-motions of shock-reflected ions. The drift motion of electrons and ions is not a gradient drift, but commensurates with E x B drift. We observe a stabl...
Universal scaling of pT distribution of particles in relativistic nuclear collisions
Zhu, L. L.; Yang, C. B.
2007-04-01
With the experimental data from the STAR, PHENIX, and BRAHMS programs on the centrality and rapidity dependence of the pT spectrum in Au+Au and d+Au collisions, we show that a scaling distribution exists that is independent of the colliding system, centrality, and rapidity. The parameter for the average transverse momentum increases from peripheral to central d+Au collisions. This increase accounts for the enhancement of particle production in those collisions. A nonextensive entropy is used to derive the scaling function.
Azfar, Farrukh
2017-01-01
This book is based on a series of lectures taught by the author to all incoming first year Oxford University postgraduates in experimental particle physics. It begins by deriving the Dirac equation and incorporating the electro-magnetic interaction and calculating several bread and butter processes at tree level using the Feynman Stueckelberg approach: Mott scattering, electron-electron scattering, electron-positron scattering, Compton scattering, Bremsstrahlung and electron-positron to muon-anti-muon. The intention is for the student to become fluent in detail with all the steps leading to the calculation of these processes. Every step is motivated using the most basic arguments.
Melekhin, Vadim N
1997-01-01
It is shown that change in transverse momentum of a relativistic particle, crossing an accelerating cavity parallel to its axis, may be presented as an integral over trajectory, the integrand of which is proportional to the component of magnetic field parallel to this axis. The changes in two transversal components of momentum are equal in value but opposite in sign. The obtained result is compared with Panofsky-Wenzel theorem.
Azevedo, F. S.; Silva, Edilberto O.; Castro, Luis B.; Filgueiras, Cleverson; Cogollo, D.
2015-11-01
The planar quantum dynamics of a spin-1/2 neutral particle interacting with electrical fields is considered. A set of first order differential equations is obtained directly from the planar Dirac equation with nonminimum coupling. New solutions of this system, in particular, for the Aharonov-Casher effect, are found and discussed in detail. Pauli equation is also obtained by studying the motion of the particle when it describes a circular path of constant radius. We also analyze the planar dynamics in the full space, including the r = 0 region. The self-adjoint extension method is used to obtain the energy levels and wave functions of the particle for two particular values for the self-adjoint extension parameter. The energy levels obtained are analogous to the Landau levels and explicitly depend on the spin projection parameter.
Some Aspects of Multi-Particle Productions in Relativistic Nuclear Collisions
Mohammad Ayaz Ahmad
2016-11-01
Full Text Available An attempt has been made for the study of multiparticle production due to the collisions of 28Si and 12C projectiles with nuclear emulsion nuclei (target at an energy of 4.5A GeV/c. Here we have studied the integral multiplicity distribution; total multiplicity charged distributions and our findings had been found in good agreement with the other works in the field of experimental high energy physics. Moreover, finally, we discussed the multiplicity correlations in terms of on Charge/Projectile (Q/Zbeam.
Relativistic mechanical-thermodynamical formalism -- description of inelastic collisions
Guemez, Julio; Fernandez, Luis A
2016-01-01
We present a relativistic formalism inspired on the Minkowski four-vectors that also includes conservation laws such as the first law of thermodynamics. It remains close to the relativistic four-vector formalism developed for a single particle, but it is also related to the classical treatment of problems that imperatively require both the Newton's second law and the energy conservation law. We apply the developed formalism to inelastic collisions to better show how it works.
On the velocity of moving relativistic unstable quantum systems
Urbanowski, K
2015-01-01
We study properties of moving relativistic quantum unstable systems. We show that in contrast to the properties of classical particles and quantum stable objects the velocity of moving freely relativistic quantum unstable systems can not be constant in time. We show that this effect results from the fundamental principles of the quantum theory and physics: It is a consequence of the principle of conservation of energy and of the fact that the mass of the quantum unstable system is not definite.
Relativistic Quantum Mechanics of N Particles - The Clebsch-Gordan Method
Polyzou, W N
2002-01-01
A general technique is presented for constructing quantum mechanical theories of a finite number of interacting particles satisfying Poincar\\'e invariance, cluster separability, and the spectral condition. It is distinguished from other solutions of this problem because it does not utilize the existence of kinematic subgroups that arise in Dirac's forms of dynamics. In the generic construction all Poincar\\'e generators have interactions. The central elements of the construction are the representation theory of the Poincar\\'e group, the theory of Birkhoff lattices, and the algebra of asymptotic constants. The role of the dynamics depends on the choice of basis used to label vectors in Poincar\\'e irreducible subspaces. The scattering equivalence and cluster equivalence of the different constructions are established. The dynamical consequences of requiring cluster properties and Poincar\\'e invariance are discussed.
Numerical Calculation of Coupling Impedances in Kicker Modules for Non-Relativistic Particle Beams
Doliwa, B
2004-01-01
In the context of heavy-ion synchrotrons, coupling impedances in ferrite-loaded structures (e.g. fast kicker modules) are known to have a significant influence on beam stability. While bench measurements are feasible today, it is desirable to have the coupling impedances in hands already during the design process of the respective components. To achieve this goal, as a first step, we have carried out numerical analyses of simple ferrite-containing test systems within the framework of the Finite Integration Technique[1]. This amounts to solving the full set of Maxwell's equations in frequency domain, the particle beam being represented by an appropriate excitation current. With the resulting electromagnetic fields, one may then readily compute the corresponding coupling impedances. Despite the complicated material properties of ferrites, our results show that their numerical treatment is possible, thus opening up a way to determine a crucial parameter of kicker devices before construction.
Relativistic particle transport in extragalactic jets: I. Coupling MHD and kinetic theory
Casse, F
2003-01-01
Multidimensional magneto-hydrodynamical (MHD) simulations coupled with stochastic differential equations (SDEs) adapted to test particle acceleration and transport in complex astrophysical flows are presented. The numerical scheme allows the investigation of shock acceleration, adiabatic and radiative losses as well as diffusive spatial transport in various diffusion regimes. The applicability of SDEs to astrophysics is first discussed in regards to the different regimes and the MHD code spatial resolution. The procedure is then applied to 2.5D MHD-SDE simulations of kilo-parsec scale extragalactic jets. The ability of SDE to reproduce analytical solutions of the diffusion-convection equation for electrons is tested through the incorporation of an increasing number of effects: shock acceleration, spatially dependent diffusion coefficients and synchrotron losses. The SDEs prove to be efficient in various shock configuration occurring in the inner jet during the development of the Kelvin-Helmholtz instability. ...
Particle description of zero energy vacuum; 1, Virtual particles
Grandpeix, J Y
2002-01-01
First the "frame problem" is sketched: the motion of an isolated particle obeys a simple law in galilean frames, but how does the galilean character of the frame manifest itself at the place of the particle? A description of vacuum as a system of virtual particles will help to answer this question. For future application to such a description, the notion of global particle is defined and studied. To this end, a systematic use of the Fourier transformation on the Poincare group is needed. The state of a system of n free particles is represented by a statistical operator W, which defines an operator-valued measure on the n-th power of the dual of the Poincare group. The inverse Fourier-Stieltjes transform of that measure is called the characteristic function of the system; it is a function on the n-th power of the Poincare group. The main notion is that of global characteristic function: it is the restriction of the characteristic function to the diagonal subgroup ; it represents the state of the system, consid...
Norbury, John W.
1992-01-01
Single nucleon removal in relativistic and intermediate energy nucleus-nucleus collisions is studied using a generalization of Weizsacker-Williams theory that treats each electromagnetic multipole separately. Calculations are presented for electric dipole and quadrupole excitations and incorporate a realistic minimum impact parameter, Coulomb recoil corrections, and the uncertainties in the input photonuclear data. Discrepancies are discussed. The maximum quadrupole effect to be observed in future experiments is estimated and also an analysis of the charge dependence of the electromagnetic cross sections down to energies as low as 100 MeV/nucleon is made.
Norbury, John W.
1992-01-01
Single nucleon removal in relativistic and intermediate energy nucleus-nucleus collisions is studied using a generalization of Weizsacker-Williams theory that treats each electromagnetic multipole separately. Calculations are presented for electric dipole and quadrupole excitations and incorporate a realistic minimum impact parameter, Coulomb recoil corrections, and the uncertainties in the input photonuclear data. Discrepancies are discussed. The maximum quadrupole effect to be observed in future experiments is estimated and also an analysis of the charge dependence of the electromagnetic cross sections down to energies as low as 100 MeV/nucleon is made.
A time of flight detector for high energy heavy particles
Fang, Z.; O`Connor, D.J. [Newcastle Univ., NSW (Australia). Dept. of Physics
1993-12-31
As a commonly used method to measure the energy of a particle with known mass, the flight time of the particle travelling over a certain distance is measured. A detector based on this principle is called a time-of-flight (TOF) detector which has attracted interests constantly during the last 15 years. For high energy heavy particle energy detection, TOF detector is an appropriated choice and such a system, developed recently, is described in this paper. 8 refs., 3 figs.
Torsion effects on a relativistic position-dependent mass system
Vitória, R L L
2016-01-01
We analyse a relativistic scalar particle with a position-dependent mass in a spacetime with a space-like dislocation by showing that relativistic bound states solutions can be achieved. Further, we consider the presence of the Coulomb potential and analyse the relativistic position-dependent mass system subject to the Coulomb potential in the spacetime with a space-like dislocation. We also show that a new set of relativistic bound states solutions can be obtained, where there also exists the influence of torsion of the relativistic energy levels. Finally, we investigate an analogue of the Aharonov-Bohm effect for bound states in this position-dependent mass in a spacetime with a space-like dislocation.
Relativistic quantum dynamics of a spinless particle in the Som-Raychaudhuri spacetime
Wang, Zhi; Long, Zheng-wen; Long, Chao-yun; Wu, Ming-li
2015-03-01
The Klein-Gordon equation under the influence of the gravitational field produced by a topology such as the Som-Raychaudhuri spacetime and the Klein-Gordon oscillator in the presence of a uniform magnetic field as well as without magnetic field are investigated. Moreover, the Klein-Gordon equation with a cylindrically symmetric scalar potential in the background spacetime is also studied. By using the quasi-analytical ansatz approach, we obtain the energy eigenvalues and corresponding wave functions of these systems. They show that the energy levels of the considered physical systems depend explicitly on the angular deficit α and the vorticity parameter Ω which characterize the global structure of the metric in the Som-Raychaudhuri spacetime.
Basu, Sumit; Datta, Kaustuv
2016-01-01
Heavy-ion collisions at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory and the Large Hadron Collider at CERN probe matter at extreme conditions of temperature and energy density. Most of the global properties of the collisions can be extracted from the measurements of charged particle multiplicity and pseudorapidity ($\\eta$) distributions. We have shown that the available experimental data on beam energy and centrality dependence of \\Eta-distributions in heavy-ion (Au+Au or Pb+Pb) collisions from \\sNN=7.7 GeV to 2.76 TeV are reasonably well described by the AMPT model, which is used for further exploration. The nature of the \\Eta-distributions has been described by a double Gaussian function using a set of fit parameters, which exhibit a regular pattern as a function of beam energy. By extrapolating the parameters to a higher energy of \\sNN~=~5.02 TeV, we have obtained the charged particle multiplicity densities, \\Eta-distributions and energy densities for various centralities. Incident...
Photon production in relativistic nuclear collisions at SPS and RHIC energies
Turbide, S; Rapp, R; 10.1142/S0217751X0402258X
2004-01-01
Chiral Lagrangians are used to compute the production rate of photons from the hadronic phase of relativistic nuclear collisions. Special attention is paid to the role of the a/sub 1/ pseudovector. Calculations that include strange meson reactions, form factors, the use of consistent vector spectral densities, the emission from a quark-gluon plasma, and primordial nucleon-nucleon collisions reproduce the photon spectra measured at the Super Proton Synchrotron (SPS). Some predictions for the Relativistic Heavy Ion Collider (RHIC) are made.
Japaridze, George
2015-01-01
I discuss an upper bound on the boost and the energy of elementary particles. The limit is derived utilizing the core principle of relativistic quantum mechanics stating that there is a lower limit for localization of an elementary quantum system and the suggestion that when the localization scale reaches the Planck length, elementary particles are removed from observables. The limit for the boost and energy, $M_{Planck}/m$ and $M_{Planck}c^{2}\\approx\\,8.6* 10^{27}$ eV, is defined in terms of fundamental constants and the mass of elementary particle and does not involve any dynamic scale. These bounds imply that the cosmic ray flux of any flavor may stretch up to energies of order $10^{18}$ GeV and will cut off at this value.
Time-dependent closure relations for relativistic collisionless fluid equations.
Bendib-Kalache, K; Bendib, A; El Hadj, K Mohammed
2010-11-01
Linear fluid equations for relativistic and collisionless plasmas are derived. Closure relations for the fluid equations are analytically computed from the relativistic Vlasov equation in the Fourier space (ω,k), where ω and k are the conjugate variables of time t and space x variables, respectively. The mathematical method used is based on the projection operator techniques and the continued fraction mathematical tools. The generalized heat flux and stress tensor are calculated for arbitrary parameter ω/kc where c is the speed of light, and for arbitrary relativistic parameter z=mc²/T , where m is the particle rest mass and T, the plasma temperature in energy units.
On the Velocity of Moving Relativistic Unstable Quantum Systems
K. Urbanowski
2015-01-01
Full Text Available We study properties of moving relativistic quantum unstable systems. We show that in contrast to the properties of classical particles and quantum stable objects the velocity of freely moving relativistic quantum unstable systems cannot be constant in time. We show that this new quantum effect results from the fundamental principles of the quantum theory and physics: it is a consequence of the principle of conservation of energy and of the fact that the mass of the quantum unstable system is not defined. This effect can affect the form of the decay law of moving relativistic quantum unstable systems.
Doornenbal, P.
2007-10-23
A two-step fragmentation experiment has been performed at GSI with the RISING setup. It combines the fragment separator FRS, which allows for the production of radioactive heavy ions at relativistic energies, with a high resolution {gamma}-spectrometer. This combination offers unique possibilities for nuclear structure investigations like the test of shell model predictions far from stability. Within the present work the question if the N=14(16) shell stabilisation in Z=8 oxygen isotopes and the N=20 shell quenching in {sup 32}Mg are symmetric with respect to the isospin projection quantum number Tz has been addressed. New {gamma}-ray decays were found in the neutron deficient {sup 36}Ca and {sup 36}K by impinging a radioactive ion beam of {sup 37}Ca on a secondary {sup 9}Be target. The fragmentation products were selected with the calorimeter telescope CATE and the emitted {gamma}-rays were measured with Ge Cluster, MINIBALL, and BaF{sub 2} HECTOR detectors. For {sup 36}Ca the 2{sub 1}{sup +}{yields}0{sub g.s.}{sup +} transition energy was determined to be 3015(16) keV, which is the heaviest T=2 nucleus from which {gamma}-spectroscopic information has been obtained so far. A comparison between the experimental 2{sub 1}{sup +} energies of {sup 36}Ca and its mirror nucleus {sup 36}S yielded a mirror energy difference of {delta}E{sub M}=-276(16) keV. In order to understand the large {delta}E{sub M} value, the experimental single-particle energies from the A=17, T=1/2 mirror nuclei were taken and applied onto modified isospin symmetric USD interactions in shell model calculations. These calculations were in agreement with the experimental result and showed that the experimental single-particle energies may account empirically for the one body part of Thomas-Ehrman and/or Coulomb effects. A method to extract the lifetime of excited states in fragmentation reactions was investigated. Therefore, the dependence between the lifetime of an excited state and the average de
Soto, F. de [Laboratoire Physique Subatomique et Cosmologie, 53 av. des Martyrs, 38026 Grenoble (France)]|[Dpto. Sistemas Fisicos, Quimicos y Naturales, U. Pablo de Olavide, 41013 Sevilla (Spain); Carbonell, J. [Laboratoire Physique Subatomique et Cosmologie, 53 av. des Martyrs, 38026 Grenoble (France)
2007-04-15
The numerical solutions of the non-relativistic Yukawa model on a 3-dimensional size lattice with periodic boundary conditions are obtained. The possibility to extract the corresponding - infinite space - low energy parameters and bound state binding energies from eigenstates computed at finite lattice size is discussed. The results have been obtained with a non relativistic model, which is justified by the small energies involved in the calculations. Despite its simplicity, the model considered contains an essential ingredient of the hadron-hadron interaction - its finite range - which plays a relevant role in view of extracting the low energy parameters from the finite volume spectra. It offers a wieldy and physically sound tool to test the validity of the different approaches discussed in the literature to study the low energy scattering of baryon-baryon or meson-baryon systems from a lattice simulations in QCD. The results presented in this work have been essentially limited to the ground state of central attractive interactions, depending only on one parameter. The method can be easily applied to more involved interactions, like hard core repulsive terms or non central potentials leading to coupled channel equations. (authors)
Hale, Alison C
2009-01-01
The spectrum of electromagnetic fields satisfying perfectly conducting boundary conditions in a segment of a straight beam pipe with a circular cross-section is discussed as a function of various source models. These include charged bunches that move along the axis of the pipe with constant speed for which an exact solution to the initial-boundary value problem for Maxwell's equations in the beam pipe is derived. In the ultra-relativistic limit all longitudinal components of the fields tend to zero and the spectral content of the transverse fields and average total electromagnetic energy crossing any section of the beam pipe are directly related to the properties of the ultra-relativistic source. It is shown that for axially symmetric ultra-relativistic bunches interference effects occur that show a striking resemblance to those that occur due to CSR in cyclic machines despite the fact that in this limit the source is no longer accelerating. The results offer an analytic description showing how such enhanced ...
Keenan, Brett; Ford, Alex; Medvedev, Mikhail
2014-10-01
Plasma turbulence in some astrophysical objects (e.g., weakly magnetized collisionless shocks in GRBs and SN) has small-scale electro-magnetic field fluctuations. We study spectral characteristics of radiation produced by particles moving in such turbulence and relate it to transport properties (diffusion) of these particles. It was shown earlier that relativistic particles produce jitter radiation, which spectral characteristics are markedly different from synchrotron radiation. Here we study radiation produced by non-relativistic particles. Unlike radiation in homogeneous field, which spectrum consists of a single cyclotron harmonic, radiation in the sub-Larmor-scale turbulence reflects statistical properties of the underlying magnetic field. We present both analytical estimates and results of ab initio numerical simulations. We also show that particle propagation in such turbulence is diffusive and evaluate the diffusion coefficient. We demonstrate that the diffusion coefficient correlates with some spectral parameters. These results can be very valuable for remote diagnostics of laboratory and astrophysical plasmas. Supported by grant DOE grant DE-FG02-07ER54940 and NSF grant AST-1209665.
M.Eshghi; M.Hamzavi; S.M.Ikhdair
2013-01-01
The spatially-dependent mass Dirac equation is solved exactly for attractive scalar and repulsive vector Coulomb potentials,including a tensor interaction under the spin and pseudospin symmetric limits.Closed forms of the energy eigenvalue equation and wave functions are obtained for arbitrary spin-orbit quantum number κ.Some numerical results are also given,and the effect of tensor interaction on the bound states is presented.It is shown that tensor interaction removes the degeneracy between two states in the spin doublets.We also investigate the effects of the spatially-dependent mass on the bound states under spin symmetric limit conditions in the absence of tensor interaction.
Characteristics of particle production in high energy nuclear collisions a model-based analysis
Guptaroy, P; Bhattacharya, S; Bhattacharya, D P
2002-01-01
The present work pertains to the production of some very important negatively charged secondaries in lead-lead and gold-gold collisions at AGS, SPS and RHIC energies. We would like to examine here the role of the particular version of sequential chain model (SCM), which was applied widely in the past in analysing data on various high-energy hadronic collisions, in explaining now the latest findings on the features of particle production in the relativistic nucleus-nucleus collisions. The agreement between the model of our choice and the measured data is found to be modestly satisfactory in cases of the most prominent and abundantly produced varieties of the secondaries in the above-stated two nuclear collisions. (25 refs).
Physics of Nonmagnetic Relativistic Thermal Plasmas. Ph.D. Thesis - Calif. Univ., San Diego
Dermer, C. D.
1984-01-01
A detailed treatment of the kinematics of relativistic systems of particles and photons is presented. In the case of a relativistic Maxwell-Boltzmann distribution of particles, the reaction rate and luminosity are written as single integrals over the invariant cross section, and the production spectrum is written as a double integral over the cross section differential in the energy of the produced particles (or photons) in the center-of-momentum system of two colliding particles. The results are applied to the calculation of the annihilation spectrum of a thermal electron-positron plasma, confirming previous numerical and analytic results. Relativistic thermal electron-ion and electron-electron bremsstrahlung are calculated exactly to lowest order, and relativistic thermal electron-positron bremsstrahlung is calculated in an approximate fashion. An approximate treatment of relativistic Comptonization is developed. The question of thermalization of a relativistic plasma is considered. A formula for the energy loss or exchange rate from the interaction of two relativistic Maxwell-Boltzmann plasmas at different temperatures is derived. Application to a stable, uniform, nonmagnetic relativistic thermal plasma is made. Comparison is made with other studies.
Ohnishi, Akira; Furumoto, Takenori
2015-01-01
We investigate $\\Lambda\\Lambda$ interaction dependence of the $\\Lambda\\Lambda$ intensity correlation in high-energy heavy-ion collisions. By analyzing the correlation data recently obtained by the STAR collaboration based on theoretically proposed $\\Lambda\\Lambda$ interactions, we give a constraint on the $\\Lambda\\Lambda$ scattering length, $-1.25~\\text{fm} < a_0 < 0$, suggesting that $\\Lambda\\Lambda$ interaction is weakly attractive and there is no loosely bound state. In addition to the fermionic quantum statistics and the $\\Lambda\\Lambda$ interaction, effects of collective flow, feed-down from $\\Sigma^0$, and the residual source are also found to be important to understand the data. We demonstrate that the correlation data favor negative $\\Lambda\\Lambda$ scattering length with the pair purity parameter $\\lambda=(0.67)^2$ evaluated by using experimental data on the $\\Sigma^0/\\Lambda$ ratio, while the positive scattering length could be favored when we regard $\\lambda$ as a free fitting parameter.
Abnormal Kinetic Energy of Charged Dust Particles in Plasmas
Norman, G.; Stegailov, V.; Timofeev, A.
A mechanism of the increase of the average kinetic energy of charged dust particles in gas discharge plasmas is suggested. Particle charge fluctuation is the reason for the appearance of forced resonance, which heals vertical oscillations. The energy transfer from vertical oscillations to the
Abnormal Kinetic Energy of Charged Dust Particles in Plasmas
Norman, G.; Stegailov, V.; Timofeev, A.
2010-01-01
A mechanism of the increase of the average kinetic energy of charged dust particles in gas discharge plasmas is suggested. Particle charge fluctuation is the reason for the appearance of forced resonance, which heals vertical oscillations. The energy transfer from vertical oscillations to the horizo
The Nature and Origin of Ultra-High Energy Cosmic Ray Particles
Biermann, Peter L; Fraschetti, Federico; Gergely, Laszlo A; Harms, Benjamin C; Kun, Emma; Lundquist, Jon Paul; Meli, Athina; Nath, Biman B; Seo, Eun-Suk; Stanev, Todor; Tjus, Julia Becker
2016-01-01
We outline two concepts to explain Ultra High Energy Cosmic Rays (UHECRs), one based on radio galaxies and their relativistic jets and terminal hot spots, and one based on relativistic Super-Novae (SNe) or Gamma Ray Bursts (GRBs) in starburst galaxies, one matching the arrival direction data in the South (the radio galaxy Cen A) and one in the North (the starburst galaxy M82). Ubiquitous neutrino emission follows accompanied by compact TeV photon emission, detectable more easily if the direction is towards Earth. The ejection of UHECRs is last. We have observed particles up to ZeV, neutrinos up to PeV, photons up to TeV, 30 - 300 Hz GW events, and hope to detect soon of order Hz to mHz GW events. Energy turnover in single low frequency GW events may be of order 10^63 erg. How can we further test these concepts? First of all by associating individual UHECR events, or directional groups of events, with chemical composition in both the Telescope Array (TA) Coll. and the Auger Coll. data. Second by identifying mo...
Chaos and maps in relativistic rynamical systems
L. P. Horwitz
2000-01-01
Full Text Available The basic work of Zaslavskii et al showed that the classical non-relativistic electromagnetically kicked oscillator can be cast into the form of an iterative map on the phase space; the resulting evolution contains a stochastic flow to unbounded energy. Subsequent studies have formulated the problem in terms of a relativistic charged particle in interaction with the electromagnetic field. We review the structure of the covariant Lorentz force used to study this problem. We show that the Lorentz force equation can be derived as well from the manifestly covariant mechanics of Stueckelberg in the presence of a standard Maxwell field, establishing a connection between these equations and mass shell constraints. We argue that these relativistic generalizations of the problem are intrinsically inaccurate due to an inconsistency in the structure of the relativistic Lorentz force, and show that a reformulation of the relativistic problem, permitting variations (classically in both the particle mass and the effective “mass” of the interacting electromagnetic field, provides a consistent system of classical equations for describing such processes.
Interphasial energy transfer and particle dissipation in particle-laden wall turbulence
Zhao, L.; Andersson, H.I.; Gillissen, J.J.J.
2013-01-01
Transfer of mechanical energy between solid spherical particles and a Newtonian carrier fluid has been explored in two-way coupled direct numerical simulations of turbulent channel flow. The inertial particles have been treated as individual point particles in a Lagrangian framework and their
Interphasial energy transfer and particle dissipation in particle-laden wall turbulence
Zhao, L.; Andersson, H.I.; Gillissen, J.J.J.
2013-01-01
Transfer of mechanical energy between solid spherical particles and a Newtonian carrier fluid has been explored in two-way coupled direct numerical simulations of turbulent channel flow. The inertial particles have been treated as individual point particles in a Lagrangian framework and their feedba
Au + Au central collisions at 150, 250 and 400 A MeV energies in QMD with relativistic forces
Németh, J; Feldmeier, H
1999-01-01
Using the small acceleration approximation we derive a relativistic scalar-vector force from a modified Zimanyi-Moszkowski Lagrangian based on sigma, omega and rho meson exchanges. The momentum dependence of the force is fixed automatically by the theory. We present an application of such a force in a QMD calculation at intermediate energies comparing the results with the experimental ones published recently by the FOPI collaboration. For most of the quantities (number of intermediate mass fragments, ERAT, integrated side flow, central flow, charge distributions, etc.) we find agreement with the experimental results.
Zhang Meng; Gou Bing-Cong
2005-01-01
Variational calculations are carried out with a multiconfiguration-interaction wavefunction on the 1s22p2p 1De and 1s22p3p 3pe states to obtain the energies including the mass polarization and relativistic corrections for the beryllium isoelectronic sequence (Z=4-10). The oscillator strengths, transition rates and wavelengths are also calculated. Our results are compared with other theoretical and experimental data in the literatures. The fine structure and hyperfine structure of 1s22p3p 3pe state are also explored.
Relativistic quantum mechanics; Mecanique quantique relativiste
Ollitrault, J.Y. [CEA Saclay, 91 - Gif-sur-Yvette (France). Service de Physique Theorique]|[Universite Pierre et Marie Curie, 75 - Paris (France)
1998-12-01
These notes form an introduction to relativistic quantum mechanics. The mathematical formalism has been reduced to the minimum in order to enable the reader to calculate elementary physical processes. The second quantification and the field theory are the logical followings of this course. The reader is expected to know analytical mechanics (Lagrangian and Hamiltonian), non-relativistic quantum mechanics and some basis of restricted relativity. The purpose of the first 3 chapters is to define the quantum mechanics framework for already known notions about rotation transformations, wave propagation and restricted theory of relativity. The next 3 chapters are devoted to the application of relativistic quantum mechanics to a particle with 0,1/5 and 1 spin value. The last chapter deals with the processes involving several particles, these processes require field theory framework to be thoroughly described. (A.C.) 2 refs.
KARSCH, F.
2006-03-26
At high temperatures or densities matter formed by strongly interacting elementary particles (hadronic matter) is expected to undergo a transition to a new form of matter--the quark gluon plasma--in which elementary particles (quarks and gluons) are no longer confined inside hadrons but are free to propagate in a thermal medium much larger in extent than the typical size of a hadron. The transition to this new form of matter as well as properties of the plasma phase are studied in large scale numerical calculations based on the theory of strong interactions--Quantum Chromo Dynamics (QCD). Experimentally properties of hot and dense elementary particle matter are studied in relativistic heavy ion collisions such as those currently performed at the relativistic heavy ion collider (RHIC) at BNL. We review here recent results from studies of thermodynamic properties of strongly interacting elementary particle matter performed on Teraflops-Computer. We present results on the QCD equation of state and discuss the status of studies of the phase diagram at non-vanishing baryon number density.
2014-01-01
It has recently been shown within a formal axiomatic framework using a definition of four-momentum based on the Stückelberg-Feynman-Sudarshan-Recami ''switching principle'' that Einstein's relativistic dynamics is logically consistent with the existence of interacting faster-than-light inertial particles. Our results here show, using only basic natural assumptions on dynamics, that this definition is the only possible way to get a consistent theory of such particles moving within the geometry of Minkowskian spacetime. We present a strictly formal proof from a streamlined axiom system that given any slow or fast inertial particle, all inertial observers agree on the value of {m}\\cdot √{|1-v^2|}, where {m} is the particle's relativistic mass and vits speed. This confirms formally the widely held belief that the relativistic mass and momentum of a positive-mass faster-than-light particle must decrease as its speed increases.
'HESPERIA' HORIZON 2020 project: High Energy Solar Particle Events foRecastIng and Analysis
Malandraki, Olga; Klein, Karl-Ludwig; Vainio, Rami; Agueda, Neus; Nunez, Marlon; Heber, Bernd; Buetikofer, Rolf; Sarlanis, Christos; Crosby, Norma; Bindi, Veronica; Murphy, Ronald; Tyka, Allan J.; Rodriguez, Juan
2016-04-01
Solar energetic particles (SEPs) are of prime interest for fundamental astrophysics. However, due to their high energies they are a space weather concern for technology in space as well as human space exploration calling for reliable tools with predictive capabilities. The two-year EU HORIZON 2020 project HESPERIA (High Energy Solar Particle Events foRecastIng and Analysis, http://www.hesperia-space.eu/) will produce two novel operational SEP forecasting tools based upon proven concepts (UMASEP, REleASE). At the same time the project will advance our understanding of the physical mechanisms that result into high-energy SEP events through the systematic exploitation of the high-energy gamma-ray observations of the FERMI mission and other novel published datasets (PAMELA, AMS), together with in situ SEP measurements near 1 AU. By using multi-frequency observations and performing simulations, the project will address the chain of processes from particle acceleration in the corona, particle transport in the magnetically complex corona and interplanetary space to their detection near 1 AU. Furthermore, HESPERIA will explore the possibility of incorporating the derived results into future innovative space weather services. Publicly available software to invert neutron monitor observations of relativistic SEPs to physical parameters, giving information on the high-energy processes occurring at or near the Sun during solar eruptions, will be provided for the first time. The results of this inversion software will complement the space-borne measurements at adjacent higher energies. In order to achieve these goals HESPERIA will exploit already existing large datasets that are stored into databases built under EU FP7 projects NMDB and SEPServer. The structure of the HESPERIA project, its main objectives and forecasting operational tools, as well as the added value to SEP research will be presented and discussed. Acknowledgement: This project has received funding from the
High-energy nuclear optics of polarized particles
Baryshevsky, Vladimir G
2012-01-01
The various phenomena caused by refraction and diffraction of polarized elementary particles in matter have opened up a new research area in the particle physics: nuclear optics of polarized particles. Effects similar to the well-known optical phenomena such as birefringence and Faraday effects, exist also in particle physics, though the particle wavelength is much less than the distance between atoms of matter. Current knowledge of the quasi-optical effects, which exist for all particles in any wavelength range (and energies from low to extremely high), will enable us to investigate different properties of interacting particles (nuclei) in a new aspect. This pioneering book will provide detailed accounts of quasi-optical phenomena in the particle polarization, and will interest physicists and professionals in experimental particle physics.
Drescher, H.J
1999-06-11
In this work we have developed hard processes and string fragmentation in the framework of interactions at relativistic energies. The hypothesis of the universality of high energy interactions means that many elements of heavy ion collisions can be studied and simulated in simpler nuclear reactions. In particular this hypothesis implies that the fragmentation observed in the reaction e{sup +}e{sup -} follows the same rules as in the collision of 2 lead ions. This work deals with 2 nuclear processes: the e{sup +}e{sup -} annihilation reaction and the deep inelastic diffusion. For the first process the string model has been developed to simulate fragmentation by adding an artificial breaking of string due to relativistic effects. A monte-Carlo method has been used to determine the points in a Minkowski space where this breaking occurs. For the second reaction, the theory of semi-hard pomerons is introduced in order to define elementary hadron-hadron interactions. The model of fragmentation proposed in this work can be applied to more complicated reactions such as proton-proton or ion-ion collisions.
Electron acceleration to relativistic energies at a strong quasi-parallel shock wave
Masters, A; Fujimoto, M; Schwartz, S J; Sergis, N; Thomsen, M F; Retinò, A; Hasegawa, H; Lewis, G R; Coates, A J; Canu, P; Dougherty, M K
2013-01-01
Electrons can be accelerated to ultrarelativistic energies at strong (high-Mach number) collisionless shock waves that form when stellar debris rapidly expands after a supernova. Collisionless shock waves also form in the flow of particles from the Sun (the solar wind), and extensive spacecraft observations have established that electron acceleration at these shocks is effectively absent whenever the upstream magnetic field is roughly parallel to the shock surface normal (quasi-parallel conditions). However, it is unclear whether this magnetic dependence of electron acceleration also applies to the far stronger shocks around young supernova remnants, where local magnetic conditions are poorly understood. Here we present Cassini spacecraft observations of an unusually strong solar system shock wave (Saturn's bow shock) where significant local electron acceleration has been confirmed under quasi-parallel magnetic conditions for the first time, contradicting the established magnetic dependence of electron accele...
M MOUSAVI; M R SHOJAEI
2017-02-01
In this work, we have obtained energy levels and charge radius for the $\\beta$-stability line nucleus, in relativistic shell model. In this model, we considered a close shell for each nucleus containing double magicnumber and a single nucleon energy level. Here we have taken $^{41}$Ca with a single neutron in the $^{40}$Ca core as an illustrative example. Then we have selected the Eckart plus Hulthen potentials for interaction between the coreand the single nucleon. By using parametric Nikiforov–Uvarov (PNU) method, we have calculated the energy values and wave function. Finally, we have calculated the charge radius for 17O, $^{41}$Ca, $^{49}$Ca and $^{57}$Ni. Our results are in agreement with experimental values and hence this model can be applied for similar nuclei.
Energy becomes riddle for particle physics
Nancy, J
2003-01-01
Assuming Einstein's theory of gravity is correct, dark energy must be present in the universe. Physicist's attempts to use quantum field theory to find the amount of dark energy present though, have been very unsuccessful (1/2 page).
Particle Acceleration in Astrophysical Sources
Amato, Elena
2015-01-01
Astrophysical sources are extremely efficient accelerators. Some sources emit photons up to multi-TeV energies, a signature of the presence, within them, of particles with energies much higher than those achievable with the largest accelerators on Earth. Even more compelling evidence comes from the study of Cosmic Rays, charged relativistic particles that reach the Earth with incredibly high energies: at the highest energy end of their spectrum, these subatomic particles are carrying a macroscopic energy, up to a few Joules. Here I will address the best candidate sources and mechanisms as cosmic particle accelerators. I will mainly focus on Galactic sources such as Supernova Remnants and Pulsar Wind Nebulae, which being close and bright, are the best studied among astrophysical accelerators. These sources are held responsible for most of the energy that is put in relativistic particles in the Universe, but they are not thought to accelerate particles up to the highest individual energies, $\\approx 10^{20}$ eV...
Calorimetry energy measurement in particle physics
Wigmans, Richard
2017-01-01
Particle physics is the science that pursues the age-old quest for the innermost structure of matter and the fundamental interactions between its constituents. Modern experiments in this field rely increasingly on calorimetry, a detection technique in which the particles of interest are absorbed in the detector. Calorimeters are very intricate instruments. Their performance characteristics depend on subtle, sometimes counter-intuitive design details. This book, written by one of the world's foremost experts, is the first comprehensive text on this topic. It provides a fundamental and systematic introduction to calorimetry. It describes the state of the art in terms of both the fundamental understanding of calorimetric particle detection, and the actual detectors that have been or are being built and operated in experiments. The last chapter discusses landmark scientific discoveries in which calorimetry has played an important role. This book summarizes and puts into perspective the work described in some 900...
Incorporate Energy Strategy into Particle Swarm Optimizer Algorithm
ZHANG Lun; DONG De-cun; LU Yan; CHEN Lan
2008-01-01
The issue of optimizing the dynamic parameters in Particle Swarm Optimizer (PSO) is addressed in this paper.An algorithm is designed which makes all particles originally endowed with a certain level energy, what here we define as EPSO (Energy Strategy PSO).During the iterative process of PSO algorithm, the Inertia Weight is updated according to the calculation of the particle's energy.The portion ratio of the current residual energy to the initial endowed energy is used as the parameter Inertia Weight which aims to update the particles' velocity efficiently.By the simulation in a graph theoritical and a functional optimization problem respectively, it could be easily found that the rate of convergence in EPSO is obviously increased.
AstroParticle Physics at the Highest Energies
Olinto, Angela V
2012-01-01
Recent international efforts have brought us closer to unveiling the century old mystery of the origin of cosmic rays. Cosmic ray, gamma ray, and neutrino observatories are reaching the necessary sensitivity to study the highest energy cosmic accelerators and to begin the use of cosmic particles to study particle interactions above laboratory energies. The number of known gamma-ray sources has increased by orders of magnitude. Possible cosmic ray sources have narrowed down with the confirmation of an ankle and the GZK-like spectral feature at the highest energies. Anisotropies in the distribution of arrival directions of cosmic rays at intermediate energies show a complex local neighborhood of the Galaxy. At the highest energies the dawn of particle astronomy is still challenging while composition related measurements point to a change in the composition or the interaction of cosmic rays at ultrahigh energies. A clear resolution of the ultrahigh energy mystery calls for a significant increase in statistics of...
Plasmoids in relativistic reconnection, from birth to adulthood: first they grow, then they go
Sironi, L; Petropoulou, M
2016-01-01
Blobs, or quasi-spherical emission regions containing relativistic particles and magnetic fields, are often assumed ad hoc in emission models of relativistic astrophysical jets, yet their physical origin is still not well understood. Here, we employ a suite of large-scale two-dimensional particle-in-cell simulations in electron-positron plasmas to demonstrate that relativistic magnetic reconnection can naturally account for the formation of quasi-spherical plasmoids filled with high-energy particles and magnetic fields. Our simulations extend to unprecedentedly long temporal and spatial scales, so we can capture the asymptotic physics independently of the initial setup. We characterize the properties of the plasmoids that are continuously generated as a self-consistent by-product of the reconnection process: they are in rough energy equipartition between particles and magnetic fields; the upper energy cutoff of the plasmoid particle spectrum is proportional to the plasmoid width w, corresponding to a Larmor r...
Brunetti, G
1999-01-01
The problem of the anisotropic Inverse Compton scattering between a monochromatic photon beam and relativistic electrons is revisited and formally solved without approximations. Solutions are given for the single scattering with an electron beam and with a population of electrons isotropically distributed, under the assumption that the energy distribution of the relativistic particles follows a simple power law as it is the case in many astrophysical applications. Both the Thomson approximation and the Klein-Nishina regime are considered for the scattering of an unpolarized photon beam. The equations are obtained without the ultra-relativistic approximation and are compared with the ultra-relativistic solutions given in the literature. The main characteristics of the power distribution and spectra of the scattered radiation are discussed for relevant examples. In the Thomson case for an isotropic electron population simple formulae holding down to mildly-relativistic energies are given. As an application the ...
Zenitani, S; Hoshino, M
2005-08-26
The linear and nonlinear evolution of a relativistic current sheet of pair (e(+/-)) plasmas is investigated by three-dimensional particle-in-cell simulations. In a Harris configuration, it is obtained that the magnetic energy is fast dissipated by the relativistic drift kink instability (RDKI). However, when a current-aligned magnetic field (the so-called "guide field") is introduced, the RDKI is stabilized by the magnetic tension force and it separates into two obliquely propagating modes, which we call the relativistic drift-kink-tearing instability. These two waves deform the current sheet so that they trigger relativistic magnetic reconnection at a crossover thinning point. Since relativistic reconnection produces a lot of nonthermal particles, the guide field is of critical importance to study the energetics of a relativistic current sheet.
Time evolution of relativistic d + Au and Au + Au collisions
Wolschin, G; Mizoguchi, T; Suzuki, N; Biyajima, Minoru; Mizoguchi, Takuya; Suzuki, Naomichi; Wolschin, Georg
2006-01-01
The evolution of charged-particle production in collisions of heavy ions at relativistic energies is investigated as function of centrality in a nonequilibrium-statistical framework. Precise agreement with recent d + Au and Au + Au data at sqrt(s_NN) = 200 GeV is found in a Relativistic Diffusion Model with three sources for particle production. Only the midrapidity source comes very close to local equilibrium, whereas the analyses of the overall pseudorapidity distributions show that the systems remain far from statistical equilibrium.
Non-Relativistic Limit of the Dirac Equation
Ajaib, Muhammad Adeel
2016-01-01
We show that the first order form of the Schrodinger equation proposed in [1] can be obtained from the Dirac equation in the non-relativistic limit. We also show that the Pauli Hamiltonian is obtained from this equation by requiring local gauge invariance. In addition, we study the problem of a spin up particle incident on a finite potential barrier and show that the known quantum mechanical results are obtained. Finally, we consider the symmetric potential well and show that the quantum mechanical expression for the quantized energy levels of a particle is obtained with periodic boundary conditions. Based on these conclusions, we propose that the equation introduced in [1] is the non-relativistic limit of the Dirac equation and more appropriately describes spin 1/2 particles in the non-relativistic limit.
Murphy, G. C.; Dieckmann, M. E.; Bret, A.; Drury, L. O'c.
2010-12-01
Context. The prompt emissions of gamma-ray bursts (GRBs) are seeded by radiating ultrarelativistic electrons. Kinetic energy dominated internal shocks propagating through a jet launched by a stellar implosion, are expected to dually amplify the magnetic field and accelerate electrons. Aims: We explore the effects of density asymmetry and of a quasi-parallel magnetic field on the collision of two plasma clouds. Methods: A two-dimensional relativistic particle-in-cell (PIC) simulation models the collision with 0.9c of two plasma clouds, in the presence of a quasi-parallel magnetic field. The cloud density ratio is 10. The densities of ions and electrons and the temperature of 131 keV are equal in each cloud, and the mass ratio is 250. The peak Lorentz factor of the electrons is determined, along with the orientation and the strength of the magnetic field at the cloud collision boundary. Results: The magnetic field component orthogonal to the initial plasma flow direction is amplified to values that exceed those expected from the shock compression by over an order of magnitude. The forming shock is quasi-perpendicular due to this amplification, caused by a current sheet which develops in response to the differing deflection of the upstream electrons and ions incident on the magnetised shock transition layer. The electron deflection implies a charge separation of the upstream electrons and ions; the resulting electric field drags the electrons through the magnetic field, whereupon they acquire a relativistic mass comparable to that of the ions. We demonstrate how a magnetic field structure resembling the cross section of a flux tube grows self-consistently in the current sheet of the shock transition layer. Plasma filamentation develops behind the shock front, as well as signatures of orthogonal magnetic field striping, indicative of the filamentation instability. These magnetic fields convect away from the shock boundary and their energy density exceeds by far the
Studies In Theoretical High Energy Particle Physics
Keung, Wai Yee [Univ. of Illinois, Chicago, IL (United States)
2017-07-01
This is a final technical report for grant no. DE-SC0007948 describing research activities in theoretical high energy physics at University of Illinois at Chicago for the whole grant period from July 1, 2012 to March 31, 2017.
Characterization of hydrophobic nanoporous particle liquids for energy absorption
Hsu, Yi; Liu, Yingtao
2016-04-01
Recently, the development of hydrophobic nanoporous technologies has drawn increased attention, especially for the applications of energy absorption and impact protection. Although significant amount of research has been conducted to synthesis and characterize materials to protect structures from impact damage, the tradition methods focused on converting kinetic energy to other forms, such as heat and cell buckling. Due to their high energy absorption efficiency, hydrophobic nanoporous particle liquids (NPLs) are one of the most attractive impact mitigation materials. During impact, such particles directly trap liquid molecules inside the non-wetting surface of nanopores in the particles. The captured impact energy is simply stored temporarily and isolated from the original energy transmission path. In this paper we will investigate the energy absorption efficiency of combinations of silica nanoporous particles and with multiple liquids. Inorganic particles, such as nanoporous silica, are characterized using scanning electron microscopy. Small molecule promoters, such as methanol and ethanol, are introduced to the prepared NPLs. Their effects on the energy absorption efficiency are studied in this paper. NPLs are prepared by dispersing the studied materials in deionized water. Energy absorption efficiency of these liquids are experimentally characterized using an Instron mechanical testing frame and in-house develop stainless steel hydraulic cylinder system.
Particle Spectra in Statistical Models with Energy and Momentum Conservation
Begun, V V; Gorenstein, M I
2012-01-01
Single particle momentum spectra are calculated within three micro-canonical statistical ensembles, namely, with conserved system energy, system momentum, as well as system energy and momentum. Deviations from the exponential spectrum of the grand canonical ensemble are quantified and discussed. For mean particle multiplicity and temperature, typical for p+p interactions at the LHC energies, the effect of the conservation laws extends to transverse momenta as low as about 3 GeV/c. The results may help to interpret spectra measured in nuclear collisions at high energies, in particular, their system size dependence.
Particle energy cascade in the intergalactic medium
Valdés, M.; Evoli, C.; Ferrara, A.
2010-05-01
We study the development of high-energy (Ein MEDEA (Monte Carlo Energy Deposition Analysis) which includes Bremsstrahlung and inverse Compton (IC) processes, along with H/He collisional ionizations and excitations, and electron-electron collisions. The cascade energy partition into heating, excitations and ionizations depends primarily not only on the IGM ionized fraction, xe, but also on redshift, z, due to IC on cosmic microwave background (CMB) photons. While Bremsstrahlung is unimportant under most conditions, IC becomes largely dominant at energies Ein >= 1 MeV. The main effect of IC at injection energies Ein = 1 GeV CMB photons are preferentially upscattered within the X-ray spectrum (hν > 104 eV) and can free stream to the observer. Complete tables of the fractional energy depositions as a function of redshift, Ein and ionized fraction are given. Our results can be used in many astrophysical contexts, with an obvious application related to the study of decaying/annihilating dark matter (DM) candidates in the high-z Universe.
Parton cascade description of relativistic heavy-ion collisions at CERN SPS energies?
Kinder-Geiger, Klaus; Geiger, Klaus; Srivastava, Dinesh Kumar
1997-01-01
We examine Pb+Pb collisions at CERN SPS energy 158 A GeV, by employing the earlier developed and recently refined parton-cascade/cluster-hadronization model and its Monte Carlo implementation. This space-time model involves the dynamical interplay of perturbative QCD parton production and evolution, with non-perturbative parton-cluster formation and hadron production through cluster decays. Using computer simulations, we are able to follow the entwined time-evolution of parton and hadron degrees of freedom in both position and momentum space, from the instant of nuclear overlap to the final yield of particles. We present and discuss results for the multiplicity distributions, which agree well with the measured data from the CERN SPS, including those for K mesons. The transverse momentum distributions of the produced hadrons are also found to be in good agreement with the preliminary data measured by the NA49 and the WA98 collaboration for the collision of lead nuclei at the CERN SPS. The analysis of the time ...
PIC Simulation of Relativistic Electromagnetic Plasma Expansion with Radiation Damping
Noguchi, Koichi; Liang, Edison; Wilks, Scott
2004-11-01
One of the unsolved problems in astrophysics is the acceleration of nonthermal high-energy particles. Nonthermal radiation is observed from pulsars, blazers, gamma-ray bursts and black holes. Recently, a new mechanism of relativistic nonthermal particle acceleration, called the Diamagnetic Relativistic Pulse Accelerator(DRPA), discovered using multi-dimensional Particle-in-Cell(PIC) simulations. When a plasma-loaded electromagnetic pulse expands relativistically, the self-induced drift current creates ponderomotive trap, which drags only the fast particles in the trap and leave slow ones behind. Here we study the effect of radiation on an electron-positron plasma accelerated by the DRPA, by introducing the radiation force in our 2D PIC code. In the radiation case, particles are accelerated by the EM pulse but decelerated by the radiation reaction simultaneously, whereas particles are accelerated indefinitely in the non-radiation case. We find that even with the radiation dumping the DRPA mechanism remains robust and particles are accelerated to over γ>100. After the simulation reaches the quasi-equilibrium state, kinetic energy becomes constant, and field energy is converted to radiation using particles as the transfer agent. We will also produce sample light waves of the radiation output.
Central Exclusive Particle Production at High Energy Hadron Colliders
Albrow, M.G.; /Fermilab; Coughlin, T.D.; /University Coll. London; Forshaw, J.R.; /Manchester U.
2010-06-01
We review the subject of central exclusive particle production at high energy hadron colliders. In particular we consider reactions of the type A + B {yields} A + X + B, where X is a fully specified system of particles that is well separated in rapidity from the outgoing beam particles. We focus on the case where the colliding particles are strongly interacting and mainly they will be protons (or antiprotons) as at the ISR, Sp{bar p}S, Tevatron and LHC. The data are surveyed and placed within the context of theoretical developments.
Itoh, Y; Asada, H; Itoh, Yousuke; Futamase, Toshifumi; Asada, Hideki
2001-01-01
We study the equation of motion appropriate to an inspiralling binary star system whose constituent stars have strong internal gravity. We use the post-Newtonian approximation with the strong field point particle limit by which we can introduce into general relativity a notion of a point-like particle with strong internal gravity without using Dirac delta distribution. Besides this limit, to deal with strong internal gravity we express the equation of motion in surface integral forms and calculate these integrals explicitly. As a result we obtain the equation of motion for a binary of compact bodies accurate through the second and half post-Newtonian (2.5 PN) order. This equation is derived in the harmonic coordinate. Our resulting equation perfectly agrees with Damour and Deruelle 2.5 PN equation of motion. Hence it is found that the 2.5 PN equation of motion is applicable to a relativistic compact binary.
Exotic Non-relativistic String
Casalbuoni, Roberto; Longhi, Giorgio
2007-01-01
We construct a classical non-relativistic string model in 3+1 dimensions. The model contains a spurion tensor field that is responsible for the non-commutative structure of the model. Under double dimensional reduction the model reduces to the exotic non-relativistic particle in 2+1 dimensions.
Electrodeposited Magnesium Nanoparticles Linking Particle Size to Activation Energy
Chaoqi Shen
2016-12-01
Full Text Available The kinetics of hydrogen absorption/desorption can be improved by decreasing particle size down to a few nanometres. However, the associated evolution of activation energy remains unclear. In an attempt to clarify such an evolution with respect to particle size, we electrochemically deposited Mg nanoparticles on a catalytic nickel and noncatalytic titanium substrate. At a short deposition time of 1 h, magnesium particles with a size of 68 ± 11 nm could be formed on the nickel substrate, whereas longer deposition times led to much larger particles of 421 ± 70 nm. Evaluation of the hydrogen desorption properties of the deposited magnesium nanoparticles confirmed the effectiveness of the nickel substrate in facilitating the recombination of hydrogen, but also a significant decrease in activation energy from 56.1 to 37.8 kJ·mol−1 H2 as particle size decreased from 421 ± 70 to 68 ± 11 nm. Hence, the activation energy was found to be intrinsically linked to magnesium particle size. Such a reduction in activation energy was associated with the decrease of path lengths for hydrogen diffusion at the desorbing MgH2/Mg interface. Further reduction in particle size to a few nanometres to remove any barrier for hydrogen diffusion would then leave the single nucleation and growth of the magnesium phase as the only remaining rate-limiting step, assuming that the magnesium surface can effectively catalyse the dissociation/recombination of hydrogen.
Tang, A H
2016-01-01
The EM field pattern created by spectators in relativistic heavy-ion collisions plants a seed of positive (negative) magnetic helicity in the hemisphere above (below) the reaction plane. Owing to the chiral anomaly, the magnetic helicity interacts with the fermionic helicity of the collision system, and causes photons emitted in upper- and lower-hemispheres to have different preferences in the circular polarization. In this paper, we lay down a procedure to measure the variation of the circular polarization w.r.t the reaction plane in relativistic heavy-ion collisions for massless photons, as well as similar polarization patterns for vector mesons decaying into two daughters. We propose to study the yield differentially and compare the yield between upper- and lower-hemispheres in order to identify and quantify such effects.
Plasmoids in relativistic reconnection, from birth to adulthood: first they grow, then they go
Sironi, Lorenzo; Giannios, Dimitrios; Petropoulou, Maria
2016-10-01
Blobs, or quasi-spherical emission regions containing relativistic particles and magnetic fields, are often assumed ad hoc in emission models of relativistic astrophysical jets, yet their physical origin is still not well understood. Here, we employ a suite of large-scale 2D particle-in-cell simulations in electron-positron plasmas to demonstrate that relativistic magnetic reconnection can naturally account for the formation of quasi-spherical plasmoids filled with high-energy particles and magnetic fields. Our simulations extend to unprecedentedly long temporal and spatial scales, so we can capture the asymptotic physics independently of the initial setup. We characterize the properties of the plasmoids, continuously generated as a self-consistent by-product of the reconnection process: they are in rough energy equipartition between particles and magnetic fields; the upper energy cutoff of the plasmoid particle spectrum is proportional to the plasmoid width w, corresponding to a Larmor radius ˜0.2 w; the plasmoids grow in size at ˜0.1 of the speed of light, with most of the growth happening while they are still non-relativistic (`first they grow'); their growth is suppressed once they get accelerated to relativistic speeds by the field line tension, up to the Alfvén speed (`then they go'). The largest plasmoids reach a width wmax ˜ 0.2 L independently of the system length L, they have nearly isotropic particle distributions and contain the highest energy particles, whose Larmor radius is ˜0.03 L. The latter can be regarded as the Hillas criterion for relativistic reconnection. We briefly discuss the implications of our results for the high-energy emission from relativistic jets and pulsar winds.
Energy momentum conservation effects on two-particle correlation functions
Bock, Nicolas
2011-01-01
Two particle correlations are used to extract information about the characteristic size of the system in proton-proton and heavy ion collisions. The size of the system can be extracted from the Bose-Einstein quantum mechanical effect for identical particles. However there are also long range correlations that shift the baseline of the correlation function from the expected flat behavior. A possible source of these correlations is the conservation of energy and momentum, especially for small systems, where the energy available for particle production is limited. A new technique, first used by the STAR collaboration, of quantifying these long range correlations using energy-momentum conservation considerations is presented in this talk. Using Monte Carlo simulations of proton-proton collisions at 900 GeV, it is shown that the baseline of the two particle correlation function can be described using this technique.
Palge, Veiko; Dunningham, Jacob; Hasegawa, Yuji
2016-01-01
In quantum physics Wigner's rotation is commonly regarded as confirmed by the Thomas precession in a hydrogen like atom. In this paper we show that a direct experimental verification of Wigner's rotation is in principle accessible in the regime of non-relativistic velocities at $2 \\cdot 10^3\\,$m/s and propose an experiment using thermal neutrons. The experiment can be carried out in a laboratory and it provides a test of relativity in the quantum domain.
(Medium energy particle physics): Annual progress report
Nefkens, B.M.K.
1985-10-01
Investigations currently carried out by the UCLA Particle Physics Research Group can be arranged into four programs: Pion-Nucleon Scattering; Tests of Charge Symmetry and Isospin Invariance; Light Nuclei (Strong Form Factors of /sup 3/H, /sup 3/He, /sup 4/He; Detailed Balance in pd /r reversible/ /gamma//sup 3/H; Interaction Dynamics); and Search for the Rare Decay /Mu//sup +/ /yields/ e/sup +/ + /gamma/ (MEGA). The general considerations which led to the choice of physics problems investigated by our group are given in the next section. We also outline the scope of the research being done which includes over a dozen experiments. The main body of this report details the research carried out in the past year, the status of various experiments, and new projects.
Energy related applications of elementary particle physics
Rafelski, J.
1991-08-31
The current research position is summarized, and what could be done in the future to clarify issues which were opened up by the research is indicated. Following on the discussion of the viability of catalyzed fusion, there is presented along with the key experimental results, a short account of the physics surrounding the subject. This is followed by a discussion of key research topics addressed. In consequence of the progress made, it appears that the feasibility of a small-scale fusion based on catalyzed reactions rests on either the remote chance that a yet undiscovered ultraheavy negatively charged elementary particle exists in Nature, or on the possible technical realization of a system based on muon-catalyzed fusion (MuCF) in high-density degenerate hydrogen plasma (density 1000 LHD, temperature O(100 eV)). The lattter is considered to have practical promise.
Lu, Z D; Fuchs, C; Zabrodin, E E; Lu, Zhong-Dao; Faesler, Amand
2002-01-01
The experimental data on hadron yields and ratios in central lead-lead and gold-gold collisions at 158 AGeV/$c$ (SPS) and $\\sqrt{s} = 130$ AGeV (RHIC), respectively, are analysed within a two-source statistical model of an ideal hadron gas. A comparison with the standard thermal model is given. The two sources, which can reach the chemical and thermal equilibrium separately and may have different temperatures, particle and strangeness densities, and other thermodynamic characteristics, represent the expanding system of colliding heavy ions, where the hot central fireball is embedded in a larger but cooler fireball. The volume of the central source increases with rising bombarding energy. Results of the two-source model fit to RHIC experimental data at midrapidity coincide with the results of the one-source thermal model fit, indicating the formation of an extended fireball, which is three times larger than the corresponding core at SPS.
Relativistic Corrections to the Bohr Model of the Atom
Kraft, David W.
1974-01-01
Presents a simple means for extending the Bohr model to include relativistic corrections using a derivation similar to that for the non-relativistic case, except that the relativistic expressions for mass and kinetic energy are employed. (Author/GS)
Vilkas, M J; Ishikawa, Y; Trabert, E
2007-03-27
Relativistic multireference many-body perturbation theory calculations have been performed on Xe{sup 43+}-Xe{sup 39+} ions, resulting in energy levels, electric dipole transition probabilities, and level lifetimes. The second-order many-body perturbation theory calculation of energy levels included mass shifts, frequency-dependent Breit correction and Lamb shifts. The calculated transition energies and E1 transition rates are used to present synthetic spectra in the extreme ultraviolet range for some of the Xe ions.
The relativistic bound states of a non-central potential
MAHDI ESHGHI; HOSSEIN MEHRABAN; SAMEER MIKHDAIR
2017-04-01
We investigate the relativistic effects of a moving particle in the field of a pseudoharmonic oscillatory ring-shaped potential under the spin and pseudospin symmetric Dirac wave equation. We obtain the bound-state energy eigenvalue equation and the corresponding two-components spinor wave functions by using the formalism of supersymmetric quantum mechanics (SUSYQM). Furthermore, the non-relativistic limits are obtained by simply making a proper replacement of parameters. The thermodynamic properties are also studied. Our numerical results for the energy eigenvalues are also presented.
Kellerman, Adam; Makarevich, Roman; Spanswick, Emma; Donovan, Eric; Shprits, Yuri
2016-07-01
Energetic electrons in the 10's of keV range precipitate to the upper D- and lower E-region ionosphere, and are responsible for enhanced ionization. The same particles are important in the inner magnetosphere, as they provide a source of energy for waves, and thus relate to relativistic electron enhancements in Earth's radiation belts.In situ observations of plasma populations and waves are usually limited to a single point, which complicates temporal and spatial analysis. Also, the lifespan of satellite missions is often limited to several years which does not allow one to infer long-term climatology of particle precipitation, important for affecting ionospheric conditions at high latitudes. Multi-point remote sensing of the ionospheric plasma conditions can provide a global view of both ionospheric and magnetospheric conditions, and the coupling between magnetospheric and ionospheric phenomena can be examined on time-scales that allow comprehensive statistical analysis. In this study we utilize multi-point riometer measurements in conjunction with in situ satellite data, and physics-based modeling to investigate the spatio-temporal and energy-dependent response of riometer absorption. Quantifying this relationship may be a key to future advancements in our understanding of the complex D-region ionosphere, and may lead to enhanced specification of auroral precipitation both during individual events and over climatological time-scales.
The Energy Conserving Particle-in-Cell Method
Markidis, Stefano
2011-01-01
A new Particle-in-Cell (PIC) method, that conserves energy exactly, is presented. The particle equations of motion and the Maxwell's equations are differenced implicitly in time by the midpoint rule and solved concurrently by a Jacobian-free Newton Krylov (JFNK) solver. Several tests show that the finite grid instability is eliminated in energy conserving PIC simulations, and the method correctly describes the two-stream and Weibel instabilities, conserving exactly the total energy. The computational time of the energy conserving PIC method increases linearly with the number of particles, and it is rather insensitive to the number of grid points and time step. The kinetic enslavement technique can be effectively used to reduce the problem matrix size and the number of JFNK solver iterations.
Demianski, Marek
2013-01-01
Relativistic Astrophysics brings together important astronomical discoveries and the significant achievements, as well as the difficulties in the field of relativistic astrophysics. This book is divided into 10 chapters that tackle some aspects of the field, including the gravitational field, stellar equilibrium, black holes, and cosmology. The opening chapters introduce the theories to delineate gravitational field and the elements of relativistic thermodynamics and hydrodynamics. The succeeding chapters deal with the gravitational fields in matter; stellar equilibrium and general relativity
Double Higgs mechanisms, supermassive stable particles and the vacuum energy
Santillán, Osvaldo P.; Gabbanelli, Luciano
2016-07-01
In the present work, a hidden scenario which cast a long-lived superheavy particle A0 and simultaneously an extremely light particle a with mass ma ˜ 10-32-10-33 eV is presented. The potential energy V (a) of the particle a models the vacuum energy density of the universe ρc ≃ 10-47GeV4. On the other hand, the A0 particle may act as superheavy dark matter at present times and the products of its decay may be observed in high energy cosmic ray events. The hidden sector proposed here include light fermions with masses near the neutrino mass mν ˜ 10-2 eV and superheavy ones with masses of the order of the GUT scale, interacting through a hidden SU(2)L interaction which also affects the ordinary sector. The construction of such combined scenario is nontrivial since the presence of light particles may spoil the stability of the heavy particle A0. However, double Higgs mechanisms may be helpful for overcoming this problem. In this context, the stability of the superheavy particle A0 is ensured due to chiral symmetry arguments elaborated in the text.
Using Energy Peaks to Measure New Particle Masses
Agashe, Kaustubh; Kim, Doojin
2014-01-01
We discussed in arXiv:1209.0772 that the laboratory frame distribution of the energy of a massless particle from a two-body decay at a hadron collider has a peak whose location is identical to the value of this daughter's (fixed) energy in the rest frame of the corresponding mother particle. For that result to hold we assumed that the mother is unpolarized and has a generic boost distribution in the laboratory frame. In this work we discuss how this observation can be applied for determination of masses of new particles, without requiring a full reconstruction of their decay chains or information about the rest of the event. We focus on a two-step cascade decay of a massive particle that has one invisible particle in the final state: C -> Bb -> Aab, where C, B and A are new particles of which A is invisible and a, b are visible particles. Combining the measurements of the peaks of energy distributions of a and b with that of the edge in their invariant mass distribution, we demonstrate that it is in principle...
Relativistic Fluid Dynamics: Physics for Many Different Scales
Comer Gregory L.
2007-01-01
Full Text Available The relativistic fluid is a highly successful model used to describe the dynamics of many-particle, relativistic systems. It takes as input basic physics from microscopic scales and yields as output predictions of bulk, macroscopic motion. By inverting the process, an understanding of bulk features can lead to insight into physics on the microscopic scale. Relativistic fluids have been used to model systems as “small” as heavy ions in collisions, and as large as the Universe itself, with “intermediate” sized objects like neutron stars being considered along the way. The purpose of this review is to discuss the mathematical and theoretical physics underpinnings of the relativistic (multiple fluid model. We focus on the variational principle approach championed by Brandon Carter and his collaborators, in which a crucial element is to distinguish the momenta that are conjugate to the particle number density currents. This approach differs from the “standard” text-book derivation of the equations of motion from the divergence of the stress-energy tensor in that one explicitly obtains the relativistic Euler equation as an “integrability” condition on the relativistic vorticity. We discuss the conservation laws and the equations of motion in detail, and provide a number of (in our opinion interesting and relevant applications of the general theory.
Abdurakhmanov, U U
2013-01-01
By the methods of mathematical statistics we test a qualitative prediction of the old theory of relativistic hydrodynamics non-viscous liquid which can be used as a part of the process of hadronization within the modern hydrodynamical approach for the description of the quark-gluon plasma. Experimental data on the interaction of protons with the energies of 0.8 TeV with emulsion nuclei are used. Results do not contradict the formation of relativistic ideal non-viscous liquid in rare central collisions.
Nuclear reactions induced by high-energy alpha particles
Shen, B. S. P.
1974-01-01
Experimental and theoretical studies of nuclear reactions induced by high energy protons and heavier ions are included. Fundamental data needed in the shielding, dosimetry, and radiobiology of high energy particles produced by accelerators were generated, along with data on cosmic ray interaction with matter. The mechanism of high energy nucleon-nucleus reactions is also examined, especially for light target nuclei of mass number comparable to that of biological tissue.
Hadron production in heavy relativistic systems
Kuiper, R; Kuiper, Rolf; Wolschin, Georg
2007-01-01
We investigate particle production in heavy-ion collisions at RHIC energies as function of incident energy, and centrality in a three-sources Relativistic Diffusion Model. Pseudorapidity distributions of produced charged hadrons in Au + Au and Cu + Cu collisions at sqrt(s_NN) = 19.6 GeV, 62.4 GeV, 130 GeV and 200 GeV show an almost equilibrated midrapidity source that tends to increase in size towards higher incident energy, and more central collisions. It may indicate quark-gluon plasma formation prior to hadronization.
Relativistic effects and quasipotential equations
Ramalho, G; Peña, M T
2002-01-01
We compare the scattering amplitude resulting from the several quasipotential equations for scalar particles. We consider the Blankenbecler-Sugar, Spectator, Thompson, Erkelenz-Holinde and Equal-Time equations, which were solved numerically without decomposition into partial waves. We analyze both negative-energy state components of the propagators and retardation effects. We found that the scattering solutions of the Spectator and the Equal-Time equations are very close to the nonrelativistic solution even at high energies. The overall relativistic effect increases with the energy. The width of the band for the relative uncertainty in the real part of the scattering $T$ matrix, due to different dynamical equations, is largest for backward-scattering angles where it can be as large as 40%.
Relativistic Kinetic Theory: An Introduction
Sarbach, Olivier
2013-01-01
We present a brief introduction to the relativistic kinetic theory of gases with emphasis on the underlying geometric and Hamiltonian structure of the theory. Our formalism starts with a discussion on the tangent bundle of a Lorentzian manifold of arbitrary dimension. Next, we introduce the Poincare one-form on this bundle, from which the symplectic form and a volume form are constructed. Then, we define an appropriate Hamiltonian on the bundle which, together with the symplectic form yields the Liouville vector field. The corresponding flow, when projected onto the base manifold, generates geodesic motion. Whenever the flow is restricted to energy surfaces corresponding to a negative value of the Hamiltonian, its projection describes a family of future-directed timelike geodesics. A collisionless gas is described by a distribution function on such an energy surface, satisfying the Liouville equation. Fibre integrals of the distribution function determine the particle current density and the stress-energy ten...
PAMELA's Measurements of Magnetospheric Effects on High Energy Solar Particles
Adriani, O; Bazilevskaya, G A; Bellotti, R; Boezio, M; Bogomolov, E A; Bongi, M; Bonvicini, V; Bottai, S; Bravar, U; Bruno, A; Cafagna, F; Campana, D; Carbone, R; Carlson, P; Casolino, M; Castellini, G; Christian, E C; De Donato, C; de Nolfo, G A; De Santis, C; De Simone, N; Di Felice, V; Formato, V; Galper, A M; Karelin, A V; Koldashov, S V; Koldobskiy, S; Krutkov, S Y; Kvashnin, A N; Lee, M; Leonov, A; Malakhov, V; Marcelli, L; Martucci, M; Mayorov, A G; Menn, W; Mergé, M; Mikhailov, V V; Mocchiutti, E; Monaco, A; Mori, N; Munini, R; Osteria, G; Palma, F; Panico, B; Papini, P; Pearce, M; Picozza, P; Ricci, M; Ricciarini, S B; Ryan, J M; Sarkar, R; Scotti, V; Simon, M; Sparvoli, R; Spillantini, P; Stochaj, S; Stozhkov, Y I; Thakur, N; Vacchi, A; Vannuccini, E; Vasilyev, G I; Voronov, S A; Yurkin, Y T; Zampa, G; Zampa, N
2015-01-01
The nature of particle acceleration at the Sun, whether through flare reconnection processes or through shocks driven by coronal mass ejections (CMEs), is still under scrutiny despite decades of research. The measured properties of solar energetic particles (SEPs) have long been modeled in different particle-acceleration scenarios. The challenge has been to disentangle to the effects of transport from those of acceleration. The Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) instrument, enables unique observations of SEPs including composition and the angular distribution of the particles about the magnetic field, i.e. pitch angle distribution, over a broad energy range (>80 MeV) -- bridging a critical gap between space-based measurements and ground-based. We present high-energy SEP data from PAMELA acquired during the 2012 May 17 SEP event. These data exhibit differential anisotropies and thus transport features over the instrument rigidity range. SEP protons exhibit two dist...
Bakke, K., E-mail: kbakke@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, 58051-900, João Pessoa-PB (Brazil); Belich, H., E-mail: belichjr@gmail.com [Departamento de Física e Química, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, 29060-900, Vitória, ES (Brazil)
2016-10-15
Based on the Standard Model Extension, we investigate relativistic quantum effects on a scalar particle in backgrounds of the Lorentz symmetry violation defined by a tensor field. We show that harmonic-type and linear-type confining potentials can stem from Lorentz symmetry breaking effects, and thus, relativistic bound state solutions can be achieved. We first analyse a possible scenario of the violation of the Lorentz symmetry that gives rise to a harmonic-type potential. In the following, we analyse another possible scenario of the breaking of the Lorentz symmetry that induces both harmonic-type and linear-type confining potentials. In this second case, we also show that not all values of the parameter associated with the intensity of the electric field are permitted in the search for polynomial solutions to the radial equation, where the possible values of this parameter are determined by the quantum numbers of the system and the parameters associated with the violation of the Lorentz symmetry.
Highest energy particle physics with the Pierre Auger Observatory
,
2014-01-01
Astroparticles offer a new path for research in the field of particle physics, allowing investigations at energies above those accesible with accelerators. Ultra-high energy cosmic rays can be studied via the observation of the showers they generate in the atmosphere. The Pierre Auger Observatory is a hybrid detector for ultra-high energy cosmic rays, combining two complementary measurement techniques used by previous experiments, to get the best possible measurements of these air showers. Shower observations enable one to not only estimate the energy, direction and most probable mass of the primary cosmic particles but also to obtain some information about the properties of their hadronic interactions. Results that are most relevant in the context of determining hadronic interaction characteristics at ultra-high energies will be presented.
Energy exchange in systems of particles with nonreciprocal interaction
Vaulina, O. S.; Lisina, I. I., E-mail: Irina.Lisina@mail.ru; Lisin, E. A. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)
2015-10-15
A model is proposed to describe the sources of additional kinetic energy and its redistribution in systems of particles with a nonreciprocal interaction. The proposed model is shown to explain the qualitative specific features of the dust particle dynamics in the sheath region of an RF discharge. Prominence is given to the systems of particles with a quasi-dipole–dipole interaction, which is similar to the interaction induced by the ion focusing effects that occur in experiments on a laboratory dusty plasma, and with the shadow interaction caused by thermophoretic forces and Le Sage’s forces.
Chainakun, P; Kara, E
2016-01-01
General relativistic ray tracing simulations of the time-averaged spectrum and energy-dependent time delays in AGN are presented. We model the lamp-post geometry in which the accreting gas is illuminated by an X-ray source located on the rotation axis of the black hole. The spectroscopic features imprinted in the reflection component are modelled using REFLIONX. The associated time delays after the direct continuum, known as reverberation lags, are computed including the full effects of dilution and ionization gradients on the disc. We perform, for the first time, simultaneous fitting of the time-averaged and lag-energy spectra in three AGN: Mrk 335, IRAS 13224-3809 and Ark 564 observed with XMM-Newton. The best fitting source height and central mass of each AGN partly agree with those previously reported. We find that including the ionization gradient in the model naturally explains lag-energy observations in which the 3 keV and 7-10 keV bands precede other bands. To obtain the clear 3 keV and 7-10 keV dips ...
Eshghi, Mahdi; Ikhdair, Sameer M
2016-01-01
We solve the Schr\\"odinger equation with a position-dependent mass (PDM) charged particle interacted via the superposition of the Morse and Coulomb potentials and exposed to external magnetic and Aharonov-Bohm (AB) flux fields. The non-relativistic bound state energies together with their wave functions are calculated for two spatially-dependent mass distribution functions. We also study the thermal quantities of such a system. Further, the canonical formalism is used to compute various thermodynamic variables for second choosing mass by using the Gibbs formalism. We give plots for energy as a function of various physical parameters. The behavior of the internal energy, specific heat and entropy as functions of temperature and mass density parameter in the inverse-square mass case for different values of magnetic field are shown.
The High Energy Particle Detector (HEPD) for the CSES satellite
Sparvoli, Roberta
2016-04-01
We present the advanced High Energy Particle Detector (HEPD) developed to be installed on the China Seismo-Electromagnetic Satellite (CSES), launch scheduled by the end of 2016. The HEPD instrument aims at studying the temporal stability of the inner Van Allen radiation belts and at investigating precipitation of trapped particles induced by magnetospheric, ionosferic and tropospheric EM emissions, as well as by the seismo-electromagnetic and anthropogenic disturbances. In occasion of many earthquakes and volcanic eruptions, several measurements, on ground and by experiments on LEO satellites revealed: electromagnetic and plasma perturbations, and anomalous increases of high-energy Van Allen charged particle flux. The precipitation of trapped electrons and protons (from a few MeV to several tens of MeV) could be induced by diffusion of particles pitch-angle possibly caused by the seismo-electromagnetic emissions generated before (a few hours) earthquakes. Due to the longitudinal drift along a same L-shell, anomalous particle bursts of precipitating particles could be detected by satellites not only on the epicentral area of the incoming earthquake, but along the drift path. Moreover, the opposite drift directions of positive and negative particles could allow reconstructing the longitude of the earthquake focal area. Although, the earthquake prediction is not within the reach of current knowledge, however the study of the precursors aims at collecting all relevant information that can infer the spatial and temporal coordinates of the seismic events from measurements. At this purposes, it is essential to detect particles in a wide range of energies (because particles of different energies are sensitive to different frequencies of seismo-electromagnetic emissions), with a good angular resolution (in order to separate fluxes of trapped and precipitating particles), and excellent ability to recognize the charge (that determines the direction of the longitudinal drift
Energy- Angular Correlation of Medium Energy Particles Produced in Heavy Ion Collisions
Hussein, M T; Sadek, N M; Elsweedy, J; Elsweedy, Jamila
2004-01-01
The nuclear photo-emulsion technique is used to study the information carried by the medium energy nucleons produced in heavy ion collisions. Multiplicity, energies as well as the angular distribution of this type of particles are measured. Due to the difficulties in measuring the energy only some particles having special criteria could be selected to measure their energy with consenting accuracy. A hypothetical model is proposed to correlate the energy of the produced particles to their emission angles so that it becomes easy to estimate the energy distribution in terms of measured emission angle. The proposed model is constructed upon statistical thermodynamic assumptions. Moreover, two additional base functions are originated that play the role of the statistical angular weight factor and the nuclear density of the compressed nuclear matter at the moment of particle emission. The prediction of the model are compared with complete set of measured data of the reactions of proton, helium, carbon and neon nucl...
High energy collisions of particles inside ergosphere: general approach
Zaslavskii, O B
2013-01-01
We show that recent observation made in Grib and Pavlov, arXiv:1301.0698 for the Kerr black hole is valid in the general case of rotating axially symmetric metric. Namely, collision of two particles in the ergosphere leads to indefinite growth of the energy in the centre of mass frame, provided the angular momentum of one of two particles is negative and increases without limit for a fixed energy at infinity. General approach enabled us to elucidate, why the role of the ergosphere in this process is crucial.
Exact Relativistic Magnetized Haloes around Rotating Disks
Antonio C. Gutiérrez-Piñeres
2015-01-01
Full Text Available The study of the dynamics of magnetic fields in galaxies is one of important problems in formation and evolution of galaxies. In this paper, we present the exact relativistic treatment of a rotating disk surrounded by a magnetized material halo. The features of the halo and disk are described by the distributional energy-momentum tensor of a general fluid in canonical form. All the relevant quantities and the metric and electromagnetic potentials are exactly determined by an arbitrary harmonic function only. For instance, the generalized Kuzmin-disk potential is used. The particular class of solutions obtained is asymptotically flat and satisfies all the energy conditions. Moreover, the motion of a charged particle on the halo is described. As far as we know, this is the first relativistic model describing analytically the magnetized halo of a rotating disk.
Bandiera, Laura; Bagli, Enrico; Guidi, Vincenzo [INFN Sezione di Ferrara and Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara, Via Saragat 1, 44121 Ferrara (Italy); Tikhomirov, Victor V. [Research Institute for Nuclear Problems, Belarusian State University, Minsk (Belarus)
2015-07-15
The analytical theories of coherent bremsstrahlung and channeling radiation well describe the process of radiation generation in crystals under some special cases. However, the treatment of complex situations requires the usage of a more general approach. In this report we present a C++ routine, named RADCHARM++, to compute the electromagnetic radiation emitted by electrons and positrons in crystals and complex structures. In the RADCHARM++ routine, the model for the computation of e.m. radiation generation is based on the direct integration of the quasiclassical formula of Baier and Katkov. This approach allows one taking into account real trajectories, and thereby the contribution of incoherent scattering. Such contribution can be very important in many cases, for instance for electron channeling. The generality of the Baier–Katkov operator method permits one to simulate the electromagnetic radiation emitted by electrons/positrons in very different cases, e.g., in straight, bent and periodically bent crystals, and for different beam energy ranges, from sub-GeV to TeV and above. The RADCHARM++ routine has been implemented in the Monte Carlo code DYNECHARM++, which solves the classical equation of motion of charged particles traveling through a crystal under the continuum potential approximation. The code has proved to reproduce the results of experiments performed at the MAinzer MIkrotron (MAMI) with 855 MeV electrons and has been used to predict the radiation spectrum generated by the same electron beam in a bent crystal.
Borghini, Nicolas; Feld, Steffen; Lang, Christian [Universitaet Bielefeld, Fakultaet fuer Physik, Postfach 100131, Bielefeld (Germany)
2015-06-15
Dissipative relativistic fluid-dynamical descriptions of the extended fireball formed in high-energy heavy-ion collisions are quite successful; yet they require a prescription for converting the fluid into particles. We present arguments in favour of using a locally anisotropic momentum distribution for the particles emitted from the fluid, so as to smooth out discontinuities introduced by the usual conversion prescriptions. Building on this ansatz, we investigate the effect of the asymmetry on several observables of heavy-ion physics. (orig.)
Thermodynamic Laws and Equipartition Theorem in Relativistic Brownian Motion
Koide, T.; Kodama, T.
2011-01-01
We extend the stochastic energetics to a relativistic system. The thermodynamic laws and equipartition theorem are discussed for a relativistic Brownian particle and the first and the second law of thermodynamics in this formalism are derived. The relation between the relativistic equipartition relation and the rate of heat transfer is discussed in the relativistic case together with the nature of the noise term.
Thermodynamic laws and equipartition theorem in relativistic Brownian motion.
Koide, T; Kodama, T
2011-06-01
We extend the stochastic energetics to a relativistic system. The thermodynamic laws and equipartition theorem are discussed for a relativistic Brownian particle and the first and the second law of thermodynamics in this formalism are derived. The relation between the relativistic equipartition relation and the rate of heat transfer is discussed in the relativistic case together with the nature of the noise term.
a Relativistic Calculation of Baryon Masses
Giammarco, Joseph Michael
1990-01-01
We calculate ground state baryon masses using a saddle-point variational (SPV) method, which permits us the use of fully relativistic 4-component Dirac spinors without the need for positive energy projection operators. This variational approach has been shown to work in the relativistic domain for one particle in an external potential (Dirac equation). We have extended its use to the relativistic 3-body Breit equation. Our procedure is as follows: we pick a trial wave function having the appropriate spin, flavor and color dependence. This can be accomplished with a non-symmetric relativistic spatial wave function having two different size parameters if the the first two quarks are always chosen to be identical. We than calculate an energy eigenvalue for the particle state and vary the parameters in our wave function to search for a "saddle-point". We minimize the energy with respect to the two size parameters and maximize with respect to two parameters that measure the contribution from the negative-energy states. This gives the baryon's mass as a function of four input parameters: the masses of the up, down and strange quarks (m_{u=d },m_{s}), and the strength of the coupling constants for the potentials ( alpha_{s},mu). We do this for the eight Baryon ground states and fit these to experimental data. This fit gives the values of the input parameters. For the potentials we use a coulombic term to represent one-gluon exchange and a linear term for confinement. For both terms we include a retardation term required by relativity. We also add delta function and spin-spin terms to account for the large contribution of the coulomb interaction at the origin. The results we obtain from our SPV method are in good agreement with experimental data. The actual search for the saddle-point parameters and the fitting of the quark masses and the values of the coupling strengths was done on a CDC Cyber 860.
Wise, John
In the near future, next-generation telescopes, covering most of the electromagnetic spectrum, will provide a view into the very earliest stages of galaxy formation. To accurately interpret these future observations, accurate and high-resolution simulations of the first stars and galaxies are vital. This proposal is centered on the formation of the first galaxies in the Universe and their observational signatures in preparation for these future observatories. This proposal has two overall goals: 1. To simulate the formation and evolution of a statistically significant sample of galaxies during the first billion years of the Universe, including all relevant astrophysics while resolving individual molecular clouds, in various cosmological environments. These simulations will utilize a sophisticated physical model of star and black hole formation and feedback, including radiation transport and magnetic fields, which will lead to the most realistic and resolved predictions for the early universe; 2. To predict the observational features of the first galaxies throughout the electromagnetic spectrum, allowing for optimal extraction of galaxy and dark matter halo properties from their photometry, imaging, and spectra; The proposed research plan addresses a timely and relevant issue to theoretically prepare for the interpretation of future observations of the first galaxies in the Universe. A suite of adaptive mesh refinement simulations will be used to follow the formation and evolution of thousands of galaxies observable with the James Webb Space Telescope (JWST) that will be launched during the second year of this project. The simulations will have also tracked the formation and death of over 100,000 massive metal-free stars. Currently, there is a gap of two orders of magnitude in stellar mass between the smallest observed z > 6 galaxy and the largest simulated galaxy from "first principles", capturing its entire star formation history. This project will eliminate this gap between simulations and observations of the first galaxies, providing predictions for next-generation observations coming online throughout the next decade. The proposed activities present the graduate students involved in the project with opportunities to gain expertise in numerical algorithms, high performance computing, and software engineering. With this experience, the students will be in a powerful position to face the challenging job market. The computational tools produced by this project will be made freely available and incorporated into their respective frameworks to preserve their sustainability.
Pollmann, Anna [Bergische Universitaet Wuppertal (Germany); Collaboration: IceCube-Collaboration
2016-07-01
Cosmic ray detectors use air as a radiator for luminescence. In water and ice detectors Cherenkov light is the dominant light producing mechanism when the particle velocity exceeds the Cherenkov threshold, approximately three quarters of the speed of light. Luminescence is produced by highly ionizing particles passing through matter due to the excitation of the surrounding atoms. The observables of luminescence, such as the wavelength spectrum and decay times, are highly dependent on the properties of the medium. Therefore, the results of measurements, in which luminescence was produced by particles passing through water or ice, vary by two orders of magnitude in intensity. It is shown that, even for the most conservative intensity value, luminescence can be used as a detection method for highly ionizing particles with velocities below the Cherenkov threshold. These could be magnetic monopoles or other massive and highly penetrating exotic particles. In the most optimistic case, luminescence contributes even to the light output of standard model particles.
Redkov, V M
1998-01-01
Some attention in the literature has been given to the case of a particle of spin 1/2 on the background of the external monopole potential. Some aspects of this problem are reexamined here. The primary technical novelty is that the tetrad generally relativistic method of Tetrode-Weyl-Fock-Ivanenko for describing a spinor particle is exploited. The choice of the formalism has turned out to be of great fruitfulness for examining the system. It is matter that, as known, the use of a special spherical tetrad in the theory of a spin 1/2 particle had led Schrodinger to a basis of remarkable features. The basis has been used with great efficiency by Pauli in his investigation on the pro- blem of allowed spherically symmetric wave functions in quantum mechanics. For our purposes, just several simple rules extracted from the much more com- prehensive Pauli's analysis will be quite sufficient; those are almost mnemo- nic working regulations. So, one may remember some very primary facts of D- functions theory and then p...
Relativistic hadrons and the origin of relativistic outflows in active galactic nuclei
Contopoulos, John; Kazanas, D.
1995-01-01
We examine the hydrodynamic origin of relativistic outflows in active galactic nuclei (AGN). Specifically, we propose that the presence of a population of relativistic hadrons in the AGN 'central engine' and the associated neutron production suffices to produce outflows which under rather general conditions could be relativistic. The main such condition is that the size of the neutron production region be larger than the neutron flight path tau(sub n) approximately 3 x 10(exp 13) cm. This condition guarantees that the mean energy per particle in the proton fluid, resulting from the decay of the neutrons outside their production region, be greater than the proton rest mass. The expansion of this fluid can then lead naturally to a relativistic outflow by conversion of its internal energy to directed motion. We follow the development of such flows by solving the mass, energy as well as the kinetic equation for the proton gas in steady state, taking into account the source terms due to compute accurately the adiabatic index of the expanding gas, and in conjunction with Bernoulli's equation the detailed evolution of the bulk Lorentz factor. We further examine the role of large-scale magnetic fields in confining these outflows to produce the jets observed at larger scales.
Consistent energy barrier distributions in magnetic particle chains
Laslett, O., E-mail: O.Laslett@soton.ac.uk [Engineering and the Environment, University of Southampton, Southampton, SO16 7QF (United Kingdom); Ruta, S.; Chantrell, R.W. [Department of Physics, University of York, York YO10 5DD (United Kingdom); Barker, J. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Friedman, G. [Electrical and Computer Engineering Department, Drexel University, Philadelphia, PA 19104 (United States); Hovorka, O. [Engineering and the Environment, University of Southampton, Southampton, SO16 7QF (United Kingdom)
2016-04-01
We investigate long-time thermal activation behaviour in magnetic particle chains of variable length. Chains are modelled as Stoner–Wohlfarth particles coupled by dipolar interactions. Thermal activation is described as a hopping process over a multidimensional energy landscape using the discrete orientation model limit of the Landau–Lifshitz–Gilbert dynamics. The underlying master equation is solved by diagonalising the associated transition matrix, which allows the evaluation of distributions of time scales of intrinsic thermal activation modes and their energy representation. It is shown that as a result of the interaction dependence of these distributions, increasing the particle chain length can lead to acceleration or deceleration of the overall relaxation process depending on the initialisation procedure.
Medical radiation dosimetry theory of charged particle collision energy loss
McParland, Brian J
2014-01-01
Accurate radiation dosimetry is a requirement of radiation oncology, diagnostic radiology and nuclear medicine. It is necessary so as to satisfy the needs of patient safety, therapeutic and diagnostic optimisation, and retrospective epidemiological studies of the biological effects resulting from low absorbed doses of ionising radiation. The radiation absorbed dose received by the patient is the ultimate consequence of the transfer of kinetic energy through collisions between energetic charged particles and atoms of the tissue being traversed. Thus, the ability of the medical physicist to both measure and calculate accurately patient dosimetry demands a deep understanding of the physics of charged particle interactions with matter. Interestingly, the physics of charged particle energy loss has an almost exclusively theoretical basis, thus necessitating an advanced theoretical understanding of the subject in order to apply it appropriately to the clinical regime. Each year, about one-third of the worl...
LI XIANG-DONG; TAN MING-LIANG; YI YOU-GEN; SHENG YONG; JIANG GANG; ZHANG ZHI-HONG; ZHU ZHENG-HE; ZHAO YONG-KUAN
2000-01-01
This paper reports the theoretical calculation of Breit, self-energy, and vacuum polarization corrections in the Ne like system using multi-configuration Dirac-Fock method with the orbital polarization. The relations of these corrections with the atomic number and the orbital symmetries are shown and the calculated correction energies are compared with other calculated results. Our Breit correction energies are all smaller by leV as maximum than the other theoretical Breit correction energies and the differences reveal systematical relation with atomic number. It is found that the configuration interactions have great effect on Breit corrections while the orbital polarization has much smaller effect on Breit corrections. The self-energy and vacuum polarization obtained by our calculation are much different from that in previous literatures for some transitions.
Fedele, Renato; De Nicola, Sergio; Shukla, P K; Jovanovic, Dusan
2011-01-01
Thermal Wave Model is used to study the strong self-consistent Plasma Wake Field interaction (transverse effects) between a strongly magnetized plasma and a relativistic electron/positron beam travelling along the external magnetic field, in the long beam limit, in terms of a nonlocal NLS equation and the virial equation. In the linear regime, vortices predicted in terms of Laguerre-Gauss beams characterized by non-zero orbital angular momentum (vortex charge). In the nonlinear regime, criteria for collapse and stable oscillations is established and the thin plasma lens mechanism is investigated, for beam size much greater than the plasma wavelength. The beam squeezing and the self-pinching equilibrium is predicted, for beam size much smaller than the plasma wavelength, taking the aberrationless solution of the nonlocal Nonlinear Schroeding equation.
Production of heavy charged Higgs particles at very high energies
Grifols, Josep Antoni; Solà Peracaula, Joan
1981-01-01
The production of heavy charged Higgs bosons at very high energies (LEP) is investigated. It turns out that, in favorable circumstances, charged scalars of mass 50-100 GeV could be detected and be even more copiously produced than the standard neutral Weinberg-Salam-type Higgs particle of the same mass.