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.
119108691
Combining neutrino oscillation experiments with the Feldman–Cousins method
In this paper we describe how two or more experimental results can be combined within the procedure of Feldman and Cousins, to provide combined confidence limits on the physical parameters of interest. We demonstrate the technique by combining the recent electron neutrino appearance results from T2K and MINOS. Our best fit point is sin2 2θ13 = 0.08 (0.11) and δ = 1.1 (2.0)π; in addition we exclude sin2 2θ13 = 0 at 2.7σ (2.8σ) for the normal (inverted) neutrino mass hierarchy.
123519082
MINOS the main injector neutrino oscillation search
Abstract MINOS is a neutrino experiment which uses a beam of neutrinos from the Fermilab main injector to determine the parameters of possible neutrino oscillations. It consists of two detectors: a near detector to measure the beam composition at the production site and a far detector 730 km away to re-measure the composition and detect any oscillation which may have occurred. MINOS is a tracking calorimeter build from solid plastic scintillators to measure all the neutrino interactions.
1135757
Status of the LBL oscillation experiments MINOS and OPERA
MINOS and OPERA will be the next generation long baseline neutrino experiments to measure neutrino oscillations as suggested by the Super-Kamiokande atmospheric neutrino results in a well controlled environment. Neutrinos produced by the Fermilab main injector will be measured by the two MINOS detectors. A near detector will be located at the Fermilab site to measure the neutrino beam composition at production, a far detector will measure it after oscillation may have modified the beam composition. OPERA will be located in the Grand Sasso underground laboratory and search for the appearance of tau neutrinos in a muon neutrino beam produced at the CERN SPS. By chance, the baseline is 735 km for both experiments.
112402914
First results of the Trip-t based T2K front end electronics performance with GM-APD
The TRIP-t front end board (TFB) will read out Geiger-mode multi-pixel Avalanche Photo-Diodes (GM-APD) in several T2K detector systems. We report the first tests of the TFB electronics with GM-APD. Measurements of GM-APD charge spectra, energy and time resolution have been performed. Individual channel voltage trimming circuit functionality has also been tested. These results indicate very good performance of the TFB prototype with both 400 and 100 pixels GMAPD from Hamamatsu photonics.
209829221
GENERALIZED GELL-MANN–LOW THEOREM APPLIED TO A SCALAR MODEL
119407344
Bound States in Yukawa Theory
A generalization of the Gell-Mann–Low Theorem is applied to lowest nontrivial order to bound state calculations in Yukawa theory. We present the solution of the corresponding effective Schrödinger equation for two-fermion bound states with the exchange of a massless boson. The complete low-lying bound state spectrum is obtained for fine structure constants below one and different ratios of the constituent masses. The consistency of the nonrelativistic and one-body limits is explicitly verified.
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.
121459809
Steps toward Dyson‐Schwinger equations for equal‐time correlation functions
Our aim is to put the partially successful analytic noncovariant approaches to Coulomb gauge QCD on a firm and systematic basis. To this end, we develop a generating functional approach to the equal‐time correlation functions. In fact, such a functional is given in terms of the vacuum wave functional, however, in a perturbative expansion of the equal‐time correlation functions, the vacuum wave functional has to be known completely to the corresponding order. In general, we find many different contributions that correspond to one and the same Feynman diagram in the covariant theory. A remarkable simplification occurs on summing up these different contributions. We analyze the relatively simpler case of λφ4 theory in detail and tentatively formulate new diagrammatic rules directly for the sum of all contributions that correspond to the same proper Feynman diagram.
15024169
Fine and hyperfine structure in different bound systems
We demonstrate that the generalized Gell-Mann–Low theorem permits for a systematic expansion around the nonrelativistic limit when applied to bound states in the Wick-Cutkosky model, Yukawa theory, and QED (in Coulomb gauge). We apply this expansion to obtain new results for the fine and hyperfine structure of bound states in the cases of the Wick-Cutkosky model and Yukawa theory, and reproduce correctly the fine and hyperfine structure of hydrogenic systems.