3,196 research outputs found
Jet reconstruction in heavy ion collisions (emphasis on Underlying Event background subtraction)
A modification of the internal structure of jets is expected due to the
production of a dense QCD medium, the Quark Gluon Plasma, in heavy-ion
collisions. We discuss some aspects of jet reconstruction in p+p and A+A
collisions and emphasize the dramatically increased contribution of the
underlying event in nucleus-nucleus collisions as compared with the vacuum
case. We conclude with its consequences on the full jet spectrum and
fragmentation function extraction at LHC.Comment: 10 pages, talk given at First International Workshop on Multiple
Partonic Interactions at the LHC, "MPI@LHC'08", Perugia, Italy, October 27-31
200
Renormalization group flows for the second parafermionic field theory for even
Extending the results obtained in the case odd, the effect of slightly
relevant perturbations of the second parafermionic field theory with the
symmetry , for even, are studied. The renormalization group
equations, and their infra red fixed points exhibit the same structure in both
cases. In addition to the standard flow from the -th to the -th
model, another fixed point corresponding to the -th model is found
Spin-Singlet Quantum Hall States and Jack Polynomials with a Prescribed Symmetry
We show that a large class of bosonic spin-singlet Fractional Quantum Hall
model wave-functions and their quasi-hole excitations can be written in terms
of Jack polynomials with a prescribed symmetry. Our approach describes new
spin-singlet quantum Hall states at filling fraction nu = 2k/(2r-1) and
generalizes the (k,r) spin-polarized Jack polynomial states. The NASS and
Halperin spin singlet states emerge as specific cases of our construction. The
polynomials express many-body states which contain configurations obtained from
a root partition through a generalized squeezing procedure involving spin and
orbital degrees of freedom. The corresponding generalized Pauli principle for
root partitions is obtained, allowing for counting of the quasihole states. We
also extract the central charge and quasihole scaling dimension, and propose a
conjecture for the underlying CFT of the (k, r) spin-singlet Jack states.Comment: 17 pages, 1 figur
Entanglement entropies of minimal models from null-vectors
We present a new method to compute R\'enyi entropies in one-dimensional
critical systems. The null-vector conditions on the twist fields in the cyclic
orbifold allow us to derive a differential equation for their correlation
functions. The latter are then determined by standard bootstrap techniques. We
apply this method to the calculation of various R\'enyi entropies in the
non-unitary Yang-Lee model.Comment: 43 pages, 7 figure
Variational Ansatz for an Abelian to non-Abelian Topological Phase Transition in Bilayers
We propose a one-parameter variational ansatz to describe the
tunneling-driven Abelian to non-Abelian transition in bosonic
fractional quantum Hall bilayers. This ansatz, based on exact matrix product
states, captures the low-energy physics all along the transition and allows to
probe its characteristic features. The transition is continuous, characterized
by the decoupling of antisymmetric degrees of freedom. We futhermore determine
the tunneling strength above which non-Abelian statistics should be observed
experimentally. Finally, we propose to engineer the inter-layer tunneling to
create an interface trapping a neutral chiral Majorana. We microscopically
characterize such an interface using a slightly modified model wavefunction.Comment: 5 pages, 4 Figures and Supplementary Materials. Comments are welcome
Matrix Product State Description and Gaplessness of the Haldane-Rezayi State
We derive an exact matrix product state representation of the Haldane-Rezayi
state on both the cylinder and torus geometry. Our derivation is based on the
description of the Haldane-Rezayi state as a correlator in a non-unitary
logarithmic conformal field theory. This construction faithfully captures the
ten degenerate ground states of this model state on the torus. Using the
cylinder geometry, we probe the gapless nature of the phase by extracting the
correlation length, which diverges in the thermodynamic limit. The numerically
extracted topological entanglement entropies seem to only probe the Abelian
part of the theory, which is reminiscent of the Gaffnian state, another model
state deriving from a non-unitary conformal field theory.Comment: Corrected labels in Fig.
- âŠ