853 research outputs found
Correlations in the Parton Recombination Model
We describe how parton recombination can address the recent measurement of
dynamical jet-like two particle correlations. In addition we discuss the
possible effect realistic light-cone wave-functions including higher
Fock-states may have on the well-known elliptic flow valence-quark number
scaling law.Comment: 4 pages, two figures, proceedings of the 18th International
Conference on Ultrarelativistic Nucleus-Nucleus Collisions: Quark Matter 2005
(QM 2005), Budapest, Hungary, 4-9 Aug 200
Phenomenology of lepton-nucleus DIS
The results of recent phenomenological studies of unpolarized nuclear
deep-inelastic scattering are discussed and applied to calculate neutrino
charged-current structure functions and cross sections for a number of nuclei.Comment: 6 pages, 5 figures, to appear in Proceedings of 4th International
Workshop On Neutrino-Nucleus Interactions In The Few-GeV Region (NuInt05),
26-29 Sep. 2005, Okayama, Japa
Thermal Recombination: Beyond the Valence Quark Approximation
Quark counting rules derived from recombination models agree well with data
on hadron production at intermediate transverse momenta in relativistic
heavy-ion collisions. They convey a simple picture of hadrons consisting only
of valence quarks. We discuss the inclusion of higher Fock states that add sea
quarks and gluons to the hadron structure. We show that, when recombination
occurs from a thermal medium, hadron spectra remain unaffected by the inclusion
of higher Fock states. However, the quark number scaling for elliptic flow is
somewhat affected. We discuss the implications for our understanding of data
from the Relativistic Heavy Ion Collider.Comment: 5 pages, 5 figure
The renormalization of the axial anomaly in dimensional regularization
The prescription for the -matrix within dimensional regularization
in multiloop calculations is elaborated. The three-loop anomalous dimension of
the singlet axial current is calculated.Comment: 11 pages, 1 figure available on request from the author,
NIKHEF-H/92-1
Directed and Elliptic Flow in Pb+Pb collisions at 40 and 158 AGeV
Directed and elliptic flow are reported for charged pions and protons as a
function of transverse momentum, rapidity, and centrality in 40 and 158 AGeV Pb
+ Pb collisions. The standard method of correlating particles with an event
plane is used. The directed flow of protons is small and shows little variation
near to midrapidity, but rises fast towards projectile rapidity in the 40 AGeV
data. For most peripheral collisions the flat region becomes negative resulting
in changing sign three times. Elliptic flow doesn't seem to change very
much from 40 AGeV to 158 AGeV. The difference is smaller than anticipated from
the overall energy dependence from AGS to RHIC.Comment: Presented at 16th International Conference on Ultrarelativistic
Nucleus-Nucelus Collisions, Quark Matter 2002 (QM 2002), Nantes, France,
18-24 Jul 2002, 4 pages, 3 figure
On the SO(N) symmetry of the chiral SU(N) Yang--Mills model
The posibility of quantizing the anomalous Yang--Mills model
preserving the symmetry under the orthogonal subgroup is indicated. The
corresponding Wess--Zumino action (1-cocycle) possesses the additional
symmetry and can be expressed in terms of chiral fields taking values in the
homogeneous space . The modified anomaly and the constraints
commutator (2-cocycle) are calculated.Comment: 9 pages, preprint PAR-LPTHE 92-48 (DECEMBER 1992), Late
Time transfer and frequency shift to the order 1/c^4 in the field of an axisymmetric rotating body
Within the weak-field, post-Newtonian approximation of the metric theories of
gravity, we determine the one-way time transfer up to the order 1/c^4, the
unperturbed term being of order 1/c, and the frequency shift up to the order
1/c^4. We adapt the method of the world-function developed by Synge to the
Nordtvedt-Will PPN formalism. We get an integral expression for the
world-function up to the order 1/c^3 and we apply this result to the field of
an isolated, axisymmetric rotating body. We give a new procedure enabling to
calculate the influence of the mass and spin multipole moments of the body on
the time transfer and the frequency shift up to the order 1/c^4. We obtain
explicit formulas for the contributions of the mass, of the quadrupole moment
and of the intrinsic angular momentum. In the case where the only PPN
parameters different from zero are beta and gamma, we deduce from these results
the complete expression of the frequency shift up to the order 1/c^4. We
briefly discuss the influence of the quadrupole moment and of the rotation of
the Earth on the frequency shifts in the ACES mission.Comment: 17 pages, no figure. Version 2. Abstract and Section II revised. To
appear in Physical Review
Anisotropic flow
Recent experimental results on directed and elliptic flow, theoretical
developments, and new techniques for anisotropic flow analysis are reviewed.Comment: 10 pages, review talk at Quark Matter 2002 conference, Nantes,
France, July 2002 Corrected typographical errors in the reference section. No
other change
Anisotropic flows from initial state of a fast nucleus
We analyze azimuthal anisotropy in heavy ion collisions related to the
reaction plane in terms of standard reggeon approach and find that it is
nonzero even when the final state interaction is switched off. This effect can
be interpreted in terms of partonic structure of colliding nuclei. We use
Feynman diagram analysis to describe details of this mechanism. Main
qualitative features of the appropriate azimuthal correlations are discussed.Comment: 16 pages, 11 figures. This paper is an extended version of a talk
given at Session of Nuclear Physics Division of Russian Academy of Sciences
in November 200
Structural Routability of n-Pairs Information Networks
Information does not generally behave like a conservative fluid flow in
communication networks with multiple sources and sinks. However, it is often
conceptually and practically useful to be able to associate separate data
streams with each source-sink pair, with only routing and no coding performed
at the network nodes. This raises the question of whether there is a nontrivial
class of network topologies for which achievability is always equivalent to
routability, for any combination of source signals and positive channel
capacities. This chapter considers possibly cyclic, directed, errorless
networks with n source-sink pairs and mutually independent source signals. The
concept of downward dominance is introduced and it is shown that, if the
network topology is downward dominated, then the achievability of a given
combination of source signals and channel capacities implies the existence of a
feasible multicommodity flow.Comment: The final publication is available at link.springer.com
http://link.springer.com/chapter/10.1007/978-3-319-02150-8_
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