121633546
Functional perturbative approach to equal-time correlation functions
Equal-time correlation functions play a central role in the recent noncovariant approaches to infrared QCD in the Coulomb gauge. In this article, we explore the possibilities to derive equal-time correlation functions from a generating functional, represent them diagrammatically, and formulate nonperturbative relations similar to Dyson–Schwinger equations among them, in analogy to the covariant n-point functions. For simplicity, we set up the formalism for λϕ4 theory and derive explicit expressions for the equal-time 2- and 4-point functions.
119161167
Perturbation theory in the Hamiltonian approach to Yang-Mills theory in Coulomb gauge
We study the Hamiltonian approach to Yang-Mills theory in Coulomb gauge in Rayleigh-Schroedinger perturbation theory. The static gluon and ghost propagator as well as the potential between static color sources are calculated to one-loop order. Furthermore, the one-loop {beta} function is calculated from both the ghost-gluon vertex and the static potential and found to agree with the result of covariant perturbation theory.
118651653
The infrared fixed point of Landau gauge Yang-Mills theory: A renormalization group analysis
The infrared behavior of gluon and ghost propagators in Landau gauge Yang-Mills theory has been at the center of an intense debate over the last decade. Different solutions of the Dyson-Schwinger equations have a different behavior of the propagators in the infrared: in the so-called scaling solutions both propagators follow a power law, while in the decoupling solutions the gluon propagator shows a massive behavior. The latest lattice results favor the decoupling solutions. In this contribution, after giving a brief overview of the present status of analytical and semi-analytical approaches to the infrared regime of Landau gauge Yang-Mills theory, we will show how Callan-Symanzik renormalization group equations in an epsilon expansion reproduce both types of solutions and single out the decoupling solutions as the infrared-stable ones for space-time dimensions greater than two, in agreement with the lattice calculations.
121014950
U(1) gauge theory on a spatial lattice: duality, photons, and shadow states
A bstractWe present a Hamiltonian approach to compact and noncompact (pure) U(1) gauge theory on a regular cubic spatial lattice in (2 + 1) and (3 + 1) dimensions. The diagonalization of the kinetic part of the Hamiltonian via Fourier transformation of the wave functionals induces an electromagnetic duality transformation. The dual variables are naturally associated with the dual lattice. The notation we borrow from algebraic topology suggests a straightforward generalization to irregular spatial lattices. We determine the states of the theory in the different representations in the strong- and weak-coupling limits, and compare the vacuum and the coherent states in the weak-coupling limit with the (shadow) states obtained some years ago by Varadarajan and Ashtekar and Lewandowski in an ultraviolet-regularized version of loop-quantized continuum U(1) gauge theory. Possible implications for the formulation of a nonperturbative renormalization group in loop-quantized theories and the description of confinement in non-abelian gauge theories are discussed.
122569817
Fermion damping and reaction rates in hot gauge theories
We examine the relation between the damping rate of a fermionic mode propagating in a hot QED or QCD plasma, and the corresponding reaction rate. We show that these two quantities should be equal provided the reaction rate is calculated using properly normalized wave functions for the mode in the medium. We use finite temperature cutting rules to identify the different terms in the expression for the damping rate with physical processes in the plasma.
14613926
The heavy quark potential from Wilson's exact renormalization group
Abstract. We perform a calculation of the full momentum dependence of the gluon and ghost propagators in pure SU(3) Yang-Mills theory by integrating Wilson's exact renormalization group equations with respect to an infrared cutoff 
$k$. The heavy quark potential in the quenched approximation can be expressed in terms of these propagators. Our results strongly indicate a 
$1/p^4$-behaviour of the heavy quark potential for 
$p^2 \to 0$. We show in general, that effective actions which satisfy Schwinger-Dyson equations, correspond to (quasi-) fixed points of Wilson's exact renormalization group equations.

14130059
Long baseline neutrino oscillation review
This article will summarise the status of current and future long baseline neutrino oscillation experiments.
122204341
New results from the MINOS experiment
MINOS is a long baseline neutrino oscillation experiment. Protons from the Fermilab main injector are used to generate an intense muon neutrino beam, which is directed at the Soudan underground laboratory in Northern Minnesota. The result from two years of running with a total exposure of 2.5 × 1020 protons on target from the NuMI beam is reported. We made a preliminary measurement by comparing the event rate and energy spectra of charge current muon neutrino interactions in the two detectors, which are 1 and 735 km from the neutrino production target. The data is consistent with vμ to v oscillation in the so-called atmospheric parameter range with δm2 = (2.38+0.20-0.16) × 10-3 eV2 and sin22Θ = 1-0.08.
121374094
T2K: A LONG-BASELINE EXPERIMENT TO STUDY NEUTRINOS
T2K is the first of a new generation of long baseline neutrino oscillation experiments that will measure neutrino oscillations parameters. The experiment uses the J-PARC accelerator complex on the east cost of Japan to sent a neutrino beam to the Kamioka mine, located 295 km to the west. It consists of a dedicated beam-line, a near detector complex to characterize the beam and the well-known Super-Kamiokande detector to measure the oscillation signal. This paper describes the experimental setup, the results of the first measurement campaign as well as giving an outlook on the future potential of the experiment.
123663776
The NuMI off-axis long baseline experiment
Several different experiments have now established that neutrinos do oscillate or may have presented experimental evidence that can be explained by neutrino oscillations [1,2,3,4,5]. The purpose of future experiments is now to measure with high precision the parameters of the neutrino mixing or so-called MNS matrix. One of those experiments is planned at the powerful NuMI neutrino beam line. The experiment is especially designed to obtain a high sensitivity for electron neutrino appearance in a muon neutrino beam. This measurement is related to the mixing angle Θ13, which is so far undetermined from previous measurements. This article will report on possible technology choices and the physics reach of the experiment.
25404962
Low background anti-neutrino monitoring with an innovative composite solid scintillator detector
The detection of anti-neutrinos from nuclear reactors at close stand-off is a challenging measurement. The requirements for a remote monitoring device that could be used for close stand-off reactor core monitoring is difficult to meet with standard liquid scintillator technologies. Due to the low rate of anti-neutrinos detectable within 10 m from research reactors the detection efficiency has to be as high as possible with a relatively compact and safe design. The more practical aspects of the system are usually difficult to meet because these systems have to be deployed at low overburden where reactor gamma-ray and neutron backgrounds are a few orders of magnitude higher than the anti-neutrino rate. Large and costly passive shielding is usually needed to reduce these backgrounds closer to the anti-neutrino rate (typically 10-4 Hz/tonne). A novel approach to measuring reactor anti-neutrinos was developed based on composite Polyvynil-Toluene and 6LiF:ZnS(Ag) scintillators. The system is highly segmented and read out by a network of wavelength shifting fibers and MPPCs which enables accurate localization of the outgoing positron and neutron. This more precise imaging of the interaction help with discriminating backgrounds and thus limits the required passive shielding around the detector. We report the expected performance from a Geant4 Monte-Carlo simulation of the system and the test of a 8 kg active mass prototype deployed at the BR2 reactor in Mol, Belgium. Measurements of the reactor on and off backgrounds rates and energy spectrum of signal candidates are presented using data collected at BR2 during summer 2013.