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A parton shower based on factorization of the quantum density matrix
414 KB  http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/45/031/45031525.pdf  Text Version
by Nagy, Zoltan (Deutsches ElektronenSynchrotron (DESY), Hamburg (Germany)); Soper, Davison E. (Oregon Univ., Eugene, OR (United States). Inst. of Theoretical Science); Deutsches ElektronenSynchrotron (DESY), Hamburg (Germany)
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414 KB  http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/45/031/45031525.pdf  Text Version
by Nagy, Zoltan (Deutsches ElektronenSynchrotron (DESY), Hamburg (Germany)); Soper, Davison E. (Oregon Univ., Eugene, OR (United States). Inst. of Theoretical Science); Deutsches ElektronenSynchrotron (DESY), Hamburg (Germany)
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[en]
We present rst results from a new parton shower event generator, DEDUCTOR. Anticipating
a need for an improved treatment of parton color and spin, the structure of the generator
is based on the quantum density matrix in color and spin space. So far, DEDUCTOR implements
only a standard spinaveraged treatment of spin in parton splittings. Although DEDUCTOR
implements an improved treatment of color, in this paper we present results in the
standard leading color approximation so that we can compare to the generator PYTHIA.
The algorithms used incorporate a virtuality based shower ordering parameter and massive
initial state bottom and charm quarks.$$$$SubjectPHYSICS OF ELEMENTARY PARTICLES AND FIELDS (S72)
Source/ReportJan 2014; 18 p; DESY13241; ISSN 04189833;
Record TypeReport
Country/Org.Germany
DECBANACH SPACE, BEAUTY PARTICLES, BOSONS, CHARM PARTICLES, COMPOSITE MODELS, COMPUTER CODES, ELEMENTARY PARTICLES, FERMIONS, FIELD THEORIES, LINEAR MOMENTUM, MASS, MATHEMATICAL LOGIC, MATHEMATICAL MODELS, MATHEMATICAL SPACE, MATRICES, ORIENTATION, PARTICLE MODELS, PARTICLE PRODUCTION, QUANTUM FIELD THEORY, QUARK MODEL, QUARKS, SHOWERS, SIMULATION, SPACE
DEIALGORITHMS, B QUARKS, C QUARKS, CASCADE SHOWERS, COLOR MODEL, COMPUTERIZED SIMULATION, D CODES, DENSITY MATRIX, FACTORIZATION, FLAVOR MODEL, GLUONS, HADRONS, HILBERT SPACE, JET MODEL, MULTIPLE PRODUCTION, PERTURBATION THEORY, QUANTUM CHROMODYNAMICS, REST MASS, SPIN ORIENTATION, TRANSVERSE MOMENTUM
LanguageEnglish
Ref. Number45031525
Publ. Year2014
INIS Volume45
INIS Issue12
Pair production of charged and doubly charged Higgs bosons at ILC in the Higgs triplet
model
http://dx.doi.org/10.1088/09543899/41/10/105003
by Shen, Jie Fen (Department of Life Science and Technology, Xinxiang Medical University, Xinxiang 453003, People's Republic of China (China)); Cao, Jun (Henan Institute of Science and Technology, Xinxiang 453003, People's Republic of China (China)), Email: shjf@xxmu.edu.cn
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http://dx.doi.org/10.1088/09543899/41/10/105003
by Shen, Jie Fen (Department of Life Science and Technology, Xinxiang Medical University, Xinxiang 453003, People's Republic of China (China)); Cao, Jun (Henan Institute of Science and Technology, Xinxiang 453003, People's Republic of China (China)), Email: shjf@xxmu.edu.cn
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[en]
The charged and doubly charged Higgs bosons (H^{±} and H^{±±}) are
the typical particles predicted by the Higgs triplet model (HTM) and the observation
of these particles might be regarded as direct evidence of the HTM. In this paper,
we investigate the pair production of the charged and doubly Higgs bosons at the International
Linear Collider (ILC): e^{+}e^{−}→H^{+}H^{−}(H^{++}H^{−−})
and e^{+}e^{−}→ZH^{+}H^{−}(H^{++}H^{−−}).
We present the production cross sections and the distributions of the various observables,
i.e., the distributions of the transverse momenta and the rapidity distributions for
outgoing particles. Our numerical results show that, as long as the charged and doubly
charged Higgs bosons masses are not too heavy, their possible signals might be detected
via these processes in future ILC experiments. A simply phenomenological analysis
is also given. (paper)$$$$SubjectPHYSICS OF ELEMENTARY PARTICLES AND FIELDS (S72)
Source/ReportJournal of Physics. G, Nuclear and Particle Physics; v. 41(10); ISSN 09543899; ; CODEN JPGPED; Oct 2014; [14 p.]; Available from http://dx.doi.org/10.1088/09543899/41/10/105003; Country of input: International Atomic Energy Agency (IAEA)
Record TypeJournal article
Country/Org.United Kingdom
DECACCELERATORS, BOSONS, CATIONS, CHARGED PARTICLES, COLLISIONS, ELECTRON COLLISIONS, ELEMENTARY PARTICLES, HYDROGEN IONS, INTERACTIONS, IONS, LINEAR ACCELERATORS, LINEAR MOMENTUM, MASS, MATHEMATICAL MODELS, MULTIPLETS, PARTICLE MODELS, PARTICLE PRODUCTION, PARTICLE PROPERTIES, POSITRON COLLISIONS, POSTULATED PARTICLES
DEICROSS SECTIONS, EFFECTIVE MASS, ELECTRONPOSITRON COLLISIONS, HIGGS BOSONS, HIGGS MODEL, HYDROGEN IONS 1 PLUS, LINEAR COLLIDERS, PAIR PRODUCTION, PARTICLE RAPIDITY, TRANSVERSE MOMENTUM, TRIPLETS
LanguageEnglish
Ref. Number46036037
Publ. Year2014
INIS Volume46
INIS Issue15
External URLhttp://dx.doi.org/10.1088/09543899/41/10/105003
Heavy pseudoscalar leadingtwist distribution amplitudes within QCD theory in background
fields
http://dx.doi.org/10.1140/epjc/s1005201532716
by Zhong, Tao; Huang, Tao (Chinese Academy of Sciences, Institute of High Energy Physics and Theoretical Physics Center for Science Facilities, Beijing (China)); Wu, XingGang (Chongqing University, Department of Physics, Chongqing (China))
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http://dx.doi.org/10.1140/epjc/s1005201532716
by Zhong, Tao; Huang, Tao (Chinese Academy of Sciences, Institute of High Energy Physics and Theoretical Physics Center for Science Facilities, Beijing (China)); Wu, XingGang (Chongqing University, Department of Physics, Chongqing (China))
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[en]
In this paper, we study the leadingtwist distribution amplitude (DA) of the heavy
pseudoscalars (HPs), such as η_{c}, η_{b}, and B_{c}, within
the QCD theory in the background fields. New sum rules up to dimensionsix condensates
for both the HP decay constants and their leadingtwist DA moments are presented.
From the sum rules for the HP decay constants, we obtain f_{ηc}
= 453 ± 4MeV, f_{Bc} = 498 ± 14 MeV, and f_{ηb}
= 811 ± 34 MeV. Based on the sum rules for the HPs' leadingtwist DA moments, we construct
a new model for the η_{c}, η_{b}, and B_{c} leadingtwist
DAs. Our present HP DA model is also adaptable for the light pseudoscalar DAs, such
as the pion and kaon DAs. Thus, it shall be applicable for a wide range of QCD exclusive
processes. As an application, we apply the η_{c} leadingtwist DA to calculate
the B_{c} → η_{c} transition form factor f_{+}^{Bc→ηc}
(q2). At the maximum recoil region, we obtain f_{+}^{Bc→ηc}
(0) = 0.612_{0.052}^{+0.053}. Furthermore we predict the branching
ratio for the semileptonic decay B_{c} → η_{c}lν and obtain B(B_{c}
→ η_{c}lν) = (7.70_{1.48}^{+1.65}) x 10^{3} for
massless leptons, which is consistent with the lightcone sum rules estimation obtained
in the literature. (orig.)$$$$SubjectPHYSICS OF ELEMENTARY PARTICLES AND FIELDS (S72)
Source/ReportEuropean physical journal. C, Particles and fields (Internet); v. 75(2); ISSN 14346052; ; Feb 2015; p. 114; Available from: http://dx.doi.org/10.1140/epjc/s1005201532716
Record TypeJournal article
Country/Org.Germany
DECBEAUTY MESONS, BEAUTY PARTICLES, BOSONS, CHARM PARTICLES, CHARMED MESONS, CHARMONIUM, COMPOSITE MODELS, DATA, DECAY, DIAGRAMS, DIMENSIONLESS NUMBERS, ELEMENTARY PARTICLES, EQUATIONS, FIELD THEORIES, FUNCTIONS, HADRONS, INFORMATION, MASS, MATHEMATICAL MODELS, MESONS, NUMERICAL DATA, PARTICLE DECAY, PARTICLE MODELS, PARTICLE PROPERTIES, PSEUDOSCALAR MESONS, QUANTUM FIELD THEORY, QUARK MODEL, QUARKONIUM, WEAK PARTICLE DECAY
DEIAMPLITUDES, B C MESONS, BOTTOMONIUM, BRANCHING RATIO, COUPLING CONSTANTS, DISTRIBUTION FUNCTIONS, ETA C2980 MESONS, FEYNMAN DIAGRAM, FLAVOR MODEL, FORM FACTORS, PARTICLE STRUCTURE, PARTICLE WIDTHS, QUANTUM CHROMODYNAMICS, REST MASS, SEMILEPTONIC DECAY, SPECTRA, SUM RULES, THEORETICAL DATA
LanguageEnglish
Ref. Number46041903
Publ. Year2015
INIS Volume46
INIS Issue17
External URLhttp://dx.doi.org/10.1140/epjc/s1005201532716
The particle spectrum of parityviolating Poincaré gravitational theory
http://dx.doi.org/10.1088/02649381/32/5/055012
by Karananas, Georgios K (Institut de Théorie des Phénomènes Physiques, École Polytechnique Fédérale de Lausanne, CH1015 Lausanne (Switzerland)), Email: georgios.karananas@epfl.ch
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http://dx.doi.org/10.1088/02649381/32/5/055012
by Karananas, Georgios K (Institut de Théorie des Phénomènes Physiques, École Polytechnique Fédérale de Lausanne, CH1015 Lausanne (Switzerland)), Email: georgios.karananas@epfl.ch
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[en]
In this paper we investigate the physical spectrum of the gravitational theory based
on the Poincaré group with terms that are at most quadratic in tetrad and spin
connection, allowing for the presence of parityeven as well as parityodd invariants.
We determine restrictions on the parameters of the action so that all degrees of freedom
propagate and are neither ghosts nor tachyons. We show that the addition of parity
nonconserving invariants extends the healthy parameter space of the theory. To accomplish
our goal, we apply the weak field approximation around flat spacetime and in order
to facilitate the analysis, we separate the bilinear action for the excitations into
completely independent spin sectors. For this purpose, we employ the spinprojection
operator formalism and extend the original basis built previously, to be able to handle
the parityodd pieces. (paper)$$$$SubjectPHYSICS OF ELEMENTARY PARTICLES AND FIELDS (S72)
Source/ReportClassical and Quantum Gravity; v. 32(5); ISSN 02649381; ; CODEN CQGRDG; 5 Mar 2015; [38 p.]; Available from http://dx.doi.org/10.1088/02649381/32/5/055012; Country of input: International Atomic Energy Agency (IAEA)
Record TypeJournal article
Country/Org.United Kingdom
DECANGULAR MOMENTUM, ELEMENTARY PARTICLES, MATHEMATICAL OPERATORS, PARTICLE PROPERTIES, POSTULATED PARTICLES
DEIPARITY, PROJECTION OPERATORS, SPACETIME, SPECTRA, SPIN, TACHYONS
LanguageEnglish
Ref. Number46049753
Publ. Year2015
INIS Volume46
INIS Issue22
External URLhttp://dx.doi.org/10.1088/02649381/32/5/055012
Beyond the Standard Model: The Weak Scale, Neutrino Mass, and the Dark Sector
http://dx.doi.org/10.2172/1036462
by Weiner, Neal; New York University (United States). Funding organisation: US Department of Energy (United States); USDOE Office of Science (United States)
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http://dx.doi.org/10.2172/1036462
by Weiner, Neal; New York University (United States). Funding organisation: US Department of Energy (United States); USDOE Office of Science (United States)
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[en]
The goal of this proposal was to advance theoretical studies into questions of collider
physics at the weak scale, models and signals of dark matter, and connections between
neutrino mass and dark energy. The project was a significant success, with a number
of developments well beyond what could have been anticipated at the outset. A total
of 35 published papers and preprints were produced, with new ideas and signals for
LHC physics and dark matter experiments, in particular. A number of new ideas have
been found on the possible indirect signals of models of dark matter which relate
to the INTEGRAL signal of astrophysical positron production, high energy positrons
seen at PAMELA and Fermi, studies into anomalous gamma rays at Fermi, collider signatures
of sneutrino dark matter, scenarios of Higgs physics arising in SUSY models, the implications
of galaxy cluster surveys for photonaxion conversion models, previously unconsidered
collider phenomenology in the form of 'lepton jets' and a very significant result
for flavor physics in supersymmetric theories. Progress continues on all fronts, including
development of models with dramatic implications for direct dark matter searches,
dynamics of dark matter with various excited states, flavor physics, and consequences
of modified missing energy signals for collider searches at the LHC.$$$$SubjectPHYSICS OF ELEMENTARY PARTICLES AND FIELDS (S72)
Source/Report20 Dec 2010; 8 p; DOE/ER41417; FG0206ER41417; Also available from OSTI as DE01036462; PURL: https://www.osti.gov/servlets/purl/1036462/; doi 10.2172/1036462
Record TypeReport
Country/Org.United States
DECANTILEPTONS, ANTIMATTER, ANTIPARTICLES, ELEMENTARY PARTICLES, ENERGY LEVELS, FERMIONS, FIELD THEORIES, GRAND UNIFIED THEORY, LEPTONS, MASSLESS PARTICLES, MATHEMATICAL MODELS, MATTER, PARTICLE MODELS, QUANTUM FIELD THEORY, UNIFIED GAUGE MODELS
DEIEXCITED STATES, GALAXY CLUSTERS, NEUTRINOS, NONLUMINOUS MATTER, PHYSICS, POSITRONS, STANDARD MODEL
LanguageEnglish
Ref. Number43083907
Publ. Year2010
INIS Volume43
INIS Issue36
External URLhttp://dx.doi.org/10.2172/1036462, https://www.osti.gov/servlets/purl/1036462, https://www.osti.gov/servlets/purl/1036462/
Energy spectra of gluinonium
http://dx.doi.org/10.1142/S0218301311040803
by Vasconcellos, C.A.Z.; Hadjimichef, D. (Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, CEP 91501970, Porto Alegre, RS (Brazil)); Silva, M.L.L. da (Universidade Federal de Pelotas, Rua Gomes Carneiro 1, CEP 96010610, Pelotas, RS (Brazil)); Razeira, M.; Mesquita, A. (Universidade de Caxias do Sul, Centro de Ciencias Exatas e Tecnologia, Rua Francisco Getulio Vargas 1130, CEP 95070560, Caxias do Sul, RS (Brazil)); Rodriguez, M.C. (Universidade Federal do Rio Grande, Av. Italia km 8, CEP 96201900, Rio Grande, RS (Brazil))
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http://dx.doi.org/10.1142/S0218301311040803
by Vasconcellos, C.A.Z.; Hadjimichef, D. (Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, CEP 91501970, Porto Alegre, RS (Brazil)); Silva, M.L.L. da (Universidade Federal de Pelotas, Rua Gomes Carneiro 1, CEP 96010610, Pelotas, RS (Brazil)); Razeira, M.; Mesquita, A. (Universidade de Caxias do Sul, Centro de Ciencias Exatas e Tecnologia, Rua Francisco Getulio Vargas 1130, CEP 95070560, Caxias do Sul, RS (Brazil)); Rodriguez, M.C. (Universidade Federal do Rio Grande, Av. Italia km 8, CEP 96201900, Rio Grande, RS (Brazil))
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[en]
We investigate relativistic bound states for a hypothetical light scalar gluino pair
(gluinonium), in the framework of the covariant BetheSalpeter equation (BSE). In
this paper, we derive, from the covariant BSE for a fermionantifermion system, using
charge conjugation, the corresponding boundstate equation for a gluino pair and we
then formulate, for a static harmonic kernel, the coupled differential equations for
the corresponding static BetheSalpeter amplitude. The steps of our approach then
include a numerical solution of the BetheSalpeter amplitude for a twobody interaction
consisting of scalar, pseudoscalar, and fourvector components and the determination
of the energy spectrum for the ground and the radially excited states of massive gluinonium.
We found the energy spectrum and radial distributions of fundamental and excited states
of gluinonium. The comparison of the values obtained in the extreme relativistic case
with the corresponding values predicted by a harmonic oscillator potential model shows
that there is good agreement between the two formulations. The predictions of the
binding energy of glunionium in the nonrelativistic model are however systematically
higher. (author)$$$$SubjectPHYSICS OF ELEMENTARY PARTICLES AND FIELDS (S72)
Source/ReportInternational Journal of Modern Physics E; v. 20(supp.2); ISSN 02183013; ; Dec 2011; p. 200209; SMFNS 2011: 2. international symposium on strong electromagnetic fields and neutron stars; Varadero (Cuba); 57 May 2011; Available from DOI: http://dx.doi.org/10.1142/S0218301311040803
Record TypeJournal article
Country/Org.Singapore
DECENERGY, ENERGY LEVELS, EQUATIONS, SPECTRA
DEIBETHESALPETER EQUATION, BINDING ENERGY, BOUND STATE, ENERGY SPECTRA, EXCITED STATES, FERMIONS, GLUEBALLS, HARMONIC OSCILLATORS, SCALARS
LanguageEnglish
Ref. Number46046098
Publ. Year2011
INIS Volume46
INIS Issue20
External URLhttp://dx.doi.org/10.1142/S0218301311040803
Recent results on the Higgs boson searches in the γγ and Zγ decay channels
with the ATLAS detector
by CARMINATI, L. (Milano Univ. and INFN, Milano(Italy))
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by CARMINATI, L. (Milano Univ. and INFN, Milano(Italy))
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[en]
In this paper the latest results on the search for a Higgs boson decaying into photon
pairs and Zγ with the ATLAS detector are reviewed. The presented measurements
are based on 4.8 fb−1 of integrated luminosity collected in 2011 at a center
of mass energy of 7TeV and 20.7 fb^{−1} collected in 2012 at a center
of mass energy of 8TeV.$$$$SubjectPHYSICS OF ELEMENTARY PARTICLES AND FIELDS (S72)
Source/ReportNuovo Cimento. C (Print); v. 37C(1); ISSN 20374909; ; Jan 2014; p. 239243
Record TypeJournal article
Country/Org.Italy
DECBOSONS, ELEMENTARY PARTICLES, FIELD THEORIES, GRAND UNIFIED THEORY, INTERMEDIATE BOSONS, INTERMEDIATE VECTOR BOSONS, MASSLESS PARTICLES, MATHEMATICAL MODELS, PARTICLE MODELS, POSTULATED PARTICLES, QUANTUM FIELD THEORY, UNIFIED GAUGE MODELS
DEIELEMENTARY PARTICLES, FERMIONS, HIGGS BOSONS, INTERMEDIATE VECTOR BOSONS, PHOTONS, STANDARD MODEL, Z NEUTRAL BOSONS
LanguageEnglish
Ref. Number46047602
Publ. Year2014
INIS Volume46
INIS Issue21
Double parton scattering. A tale of two partons
1 MB  http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/44/111/44111315.pdf  Text Version
by Kasemets, Tomas; Deutsches ElektronenSynchrotron (DESY), Hamburg (Germany); Hamburg Univ. (Germany). Dept. Physik
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1 MB  http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/44/111/44111315.pdf  Text Version
by Kasemets, Tomas; Deutsches ElektronenSynchrotron (DESY), Hamburg (Germany); Hamburg Univ. (Germany). Dept. Physik
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[en]
Double parton scattering in protonproton collisions can give sizable contributions
to final states in parts of phase space. We investigate the correlations between the
partons participating in the two hard interactions of double parton scattering. With
a detailed calculation of the differential cross section for the double DrellYan
process we demonstrate how initial state correlations between the partons affect the
rate and distribution of final state particles. We present our results with focus
on correlations between the polarizations of the partons. In particular transversely
polarized quarks lead to a dependence of the cross section on angles between final
state particles of the two hard interactions, and thereby on the invariant mass of
particle pairs. The size of the spin correlations, and therewith the degree to which
the final state particles are correlated, depends on unknown double parton distributions.
We derive positivity bounds on the double parton distributions that follow from their
interpretation as probability densities, taking into account all possible spin correlations
between two partons in an unpolarized proton. We show that the bounds are stable under
homogeneous leadingorder DGLAP evolution to higher scales. We make direct use of
the positivity bounds in numerical investigations on the double DGLAP evolution for
two linearly polarized gluons and for two transversely polarized quarks. We find that
the linearly polarized gluons are likely to be negligible at high scales but that
transversely polarized quarks can still play a significant role. We examine the dependence
of the double parton distributions on the transverse distance between the two partons,
and therewith between the two hard interactions. We further study the interplay between
transverse and longitudinal variables of the distributions, as well as the impact
of the differences in integration limits between the evolution equations for single
and double parton distributions. (orig.)$$$$SubjectPHYSICS OF ELEMENTARY PARTICLES AND FIELDS (S72)
Source/ReportAug 2013; 107 p; DESYTHESIS2013035; ISSN 14358085; ; Diss.
Record TypeThesis/Dissertation
Country/Org.Germany
DECBARYONBARYON INTERACTIONS, BARYONS, CORRELATIONS, CROSS SECTIONS, DIMENSIONLESS NUMBERS, ELEMENTARY PARTICLES, EQUATIONS, FERMIONS, HADRONHADRON INTERACTIONS, HADRONS, INTERACTIONS, MASS, MATHEMATICAL SOLUTIONS, MATRICES, NUCLEONNUCLEON INTERACTIONS, NUCLEONS, ORIENTATION, PARTICLE INTERACTIONS, PARTICLE PRODUCTION, PROTONNUCLEON INTERACTIONS, SCATTERING, SPECTRA
DEIANGULAR CORRELATION, DENSITY MATRIX, DIFFERENTIAL CROSS SECTIONS, DIFFERENTIAL EQUATIONS, DISTRIBUTION, DRELL MODEL, EFFECTIVE MASS, GLUONGLUON INTERACTIONS, MASS SPECTRA, MULTIPLE SCATTERING, NUMERICAL SOLUTION, PAIR PRODUCTION, PARTICLE STRUCTURE, POLARIZATIONASYMMETRY RATIO, PROBABILITY, PROTONPROTON INTERACTIONS, PROTONS, QUARKQUARK INTERACTIONS, SPIN ORIENTATION
LanguageEnglish
Ref. Number44111315
Publ. Year2013
INIS Volume44
INIS Issue47
Dynamic and thermodynamic stability of relativistic, perfect fluid stars
http://dx.doi.org/10.1088/02649381/31/3/035023
by Green, Stephen R (Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1 (Canada)); Schiffrin, Joshua S; Wald, Robert M (Enrico Fermi Institute and Department of Physics, The University of Chicago, 5640 S Ellis Ave., Chicago, IL 60637 (United States)), Email: sgreen04@uoguelph.ca, Email: schiffrin@uchicago.edu, Email: rmwa@uchicago.edu
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http://dx.doi.org/10.1088/02649381/31/3/035023
by Green, Stephen R (Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1 (Canada)); Schiffrin, Joshua S; Wald, Robert M (Enrico Fermi Institute and Department of Physics, The University of Chicago, 5640 S Ellis Ave., Chicago, IL 60637 (United States)), Email: sgreen04@uoguelph.ca, Email: schiffrin@uchicago.edu, Email: rmwa@uchicago.edu
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[en]
We consider perfect fluid bodies (‘stars’) in general relativity, with
the local state of the fluid specified by its 4velocity, u^{a}, its ‘particle
number density’, n, and its ‘entropy per particle’, s. A star is
said to be in dynamic equilibrium if it is a stationary, axisymmetric solution to
the Einsteinfluid equations with circular flow. A star is said to be in thermodynamic
equilibrium if it is in dynamic equilibrium and its total entropy, S, is an extremum
for all variations of initial data that satisfy the Einstein constraint equations
and have fixed total mass, M, particle number, N, and angular momentum, J. We prove
that for a star in dynamic equilibrium, the necessary and sufficient condition for
thermodynamic equilibrium is constancy of angular velocity, Ω, redshifted temperature,
Ttilde , and redshifted chemical potential, μtilde . A star in dynamic equilibrium
is said to be linearly dynamically stable if all physical, gauge invariant quantities
associated with linear perturbations of the star remain bounded in time; it is said
to be mode stable if there are no exponentially growing solutions that are not pure
gauge. A star in thermodynamic equilibrium is said to be linearly thermodynamically
stable if δ^{2}S < 0 for all variations at fixed M, N, and J; equivalently,
a star in thermodynamic equilibrium is linearly thermodynamically stable if δ^{2}M−
Ttilde δ^{2}S− μtilde δ^{2}N−Ωδ^{2}J>0
for all variations that, to first order, satisfy δM = δN = δJ = 0 (and,
hence, δS = 0). Friedman previously identified positivity of canonical energy,
E, as a criterion for dynamic stability and argued that all rotating stars are dynamically
unstable to sufficiently nonaxisymmetric perturbations (the CFS instability), so
our main focus is on axisymmetric stability (although we develop our formalism and
prove many results for nonaxisymmetric perturbations as well). We show that for a
star in dynamic equilibrium, mode stability holds with respect to all axisymmetric
perturbations if E is positive on a certain subspace, V, of axisymmetric Lagrangian
perturbations that, in particular, have vanishing Lagrangian change in angular momentum
density. Conversely, if E fails to be positive on V, then there exist perturbations
that cannot become asymptotically stationary at late times. We further show that for
a star in thermodynamic equilibrium, for all Lagrangian perturbations, we have E_{r}=δ^{2}M−Ωδ^{2}J,
where E_{r} denotes the ‘canonical energy in the rotating frame’,
so positivity of E_{r} for perturbations with δJ = 0 is a necessary condition
for thermodynamic stability. For axisymmetric perturbations, we have E=E_{r},
so a necessary condition for thermodynamic stability with respect to axisymmetric
perturbations is positivity of E on all perturbations with δJ = 0, not merely
on the perturbations in V. Many of our results are in close parallel with the results
of Hollands and Wald for the theory of black holes. (paper)$$$$SubjectPHYSICS OF ELEMENTARY PARTICLES AND FIELDS (S72)
Source/ReportClassical and Quantum Gravity; v. 31(3); ISSN 02649381; ; CODEN CQGRDG; 7 Feb 2014; [38 p.]; Available from http://dx.doi.org/10.1088/02649381/31/3/035023; Country of input: International Atomic Energy Agency (IAEA)
Record TypeJournal article
Country/Org.United Kingdom
DECENERGY RANGE, FIELD THEORIES, FLUID FLOW, FUNCTIONS, INCOMPRESSIBLE FLOW, INVARIANCE PRINCIPLES, PHYSICAL PROPERTIES, RELATIVITY THEORY, STEADY FLOW, SYMMETRY, THERMODYNAMIC PROPERTIES, VELOCITY
DEIANGULAR VELOCITY, AXIAL SYMMETRY, DISTURBANCES, ENTROPY, EQUILIBRIUM, GAUGE INVARIANCE, GENERAL RELATIVITY THEORY, IDEAL FLOW, LAGRANGIAN FUNCTION, PERTURBATION THEORY, RED SHIFT, RELATIVISTIC RANGE, STARS
LanguageEnglish
Ref. Number46047198
Publ. Year2014
INIS Volume46
INIS Issue21
External URLhttp://dx.doi.org/10.1088/02649381/31/3/035023
Precision Photometry to Study the Nature of Dark Energy
http://dx.doi.org/10.2172/1004171
by Lorenzon, Wolfgang; Schubnell, Michael; University of Michigan, Ann Arbor, MI (United States). Funding organisation: USDOE Office of Science (United States)
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http://dx.doi.org/10.2172/1004171
by Lorenzon, Wolfgang; Schubnell, Michael; University of Michigan, Ann Arbor, MI (United States). Funding organisation: USDOE Office of Science (United States)
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[en]
Over the past decade scientists have collected convincing evidence that the expansion
of the universe is accelerating, leading to the conclusion that the content of our
universe is dominated by a mysterious 'dark energy'. The fact that present theory
cannot account for the dark energy has made the determination of the nature of dark
energy central to the field of high energy physics. It is expected that nothing short
of a revolution in our understanding of the fundamental laws of physics is required
to fully understand the accelerating universe. Discovering the nature of dark energy
is a very difficult task, and requires experiments that employ a combination of different
observational techniques, such as typeIa supernovae, gravitational weak lensing surveys,
galaxy and galaxy cluster surveys, and baryon acoustic oscillations. A critical component
of any approach to understanding the nature of dark energy is precision photometry.
This report addresses just that. Most dark energy missions will require photometric
calibration over a wide range of intensities using standardized stars and internal
reference sources. All of the techniques proposed for these missions rely on a complete
understanding of the linearity of the detectors. The technical report focuses on the
investigation and characterization of 'reciprocity failure', a newly discovered countrate
dependent nonlinearity in the NICMOS cameras on the Hubble Space Telescope. In order
to quantify reciprocity failure for modern astronomical detectors, we built a dedicated
reciprocity test setup that produced a known amount of light on a detector, and to
measured its response as a function of light intensity and wavelength.$$$$SubjectCLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS (S71), PHYSICS OF ELEMENTARY PARTICLES AND FIELDS (S72)
Source/Report30 Jan 2011; 2 p; DOE/ER41566; FG0208ER41566; Also available from OSTI as DE01004171; PURL: https://www.osti.gov/servlets/purl/1004171/; doi: http://dx.doi.org/10.2172/1004171
Record TypeReport
Country/Org.United States
DECBINARY STARS, ELEMENTARY PARTICLES, ERUPTIVE VARIABLE STARS, FERMIONS, HADRONS, PHYSICS, STARS, VARIABLE STARS
DEIACCURACY, ACOUSTICS, BARYONS, CALIBRATION, CAMERAS, GALAXY CLUSTERS, HIGH ENERGY PHYSICS, OSCILLATIONS, PHOTOMETRY, PHYSICS, STARS, SUPERNOVAE, UNIVERSE
LanguageEnglish
Ref. Number43083911
Publ. Year2011
INIS Volume43
INIS Issue36
External URLhttp://dx.doi.org/10.2172/1004171, https://www.osti.gov/servlets/purl/1004171, https://www.osti.gov/servlets/purl/1004171/
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