123232350
Relation Between Quantum and Thermal Fluctuations
Abstract A relation between quantum and thermal fluctuations, called the generalized uncertainty relation, is derived and discussed. It is given in the terminology of thermo field dynamics. The relation enables us to separate the purely thermal fluctuation from the total fluctuation.
40587572
Inverted spectroscopy and interferometry for quantum-state reconstruction of systems with SU(2) symmetry
We consider how the conventional spectroscopic and interferometric schemes can be rearranged to serve for reconstructing quantum states of physical systems possessing SU(2) symmetry. The discussed systems include a collection of two-level atoms, a two-mode quantized radiation field with a fixed total number of photons, and a single laser-cooled ion in a two-dimensional harmonic trap with a fixed total number of vibrational quanta. In the proposed rearrangement, the standard spectroscopic and interferometric experiments are inverted. Usually one measures an unknown frequency or phase shift using a system prepared in a known quantum state. Our aim is just the inverse, i.e., to use a well-calibrated apparatus with known transformation parameters to measure unknown quantum states.
119995096
Coherent and thermal coherent state
The characterization of coherent states as the quantum states that split into two uncorrelated beams is considered. The characterization leads to the study of coherent states at finite temperature—thermal coherent states (TCS’s). These TCS’s are defined within the formalism of thermo field dynamics (TFD). TFD allows a generalization of the uncertainty relation that accounts for both thermal and quantum fluctuations. The TCS is shown to be a minimal state for the generalized uncertainty relation.
16492315
Empirical State Determination of Entangled Two-Level Systems and Its Relation to Information Theory
Theoretical methods for empirical state determination of entangled two-level systems are analyzed in relation to information theory. We show that hidden variable theories would lead to a Shannon index of correlation between the entangled subsystems which is larger than that predicted by quantum mechanics. Canonical representations which have maximal correlations are treated by the use of Schmidt and Hilbert-Schmidt decomposition of the entangled states, including especially the Bohm singlet state and the GHZ entangled states. We show that quantum mechanics does not violate locality, but does violate realism.
16820646
Analytic representations based on SU(1,1) coherent states and their applications
We consider two analytic representations of the SU(1,1) Lie group: the representation in the unit disc based on the SU(1,1) Perelomov coherent states and the Barut - Girardello representation based on the eigenstates of the SU(1,1) lowering generator. We show that these representations are related through a Laplace transform. A `weak' resolution of the identity in terms of the Perelomov SU(1,1) coherent states is presented which is valid even when the Bargmann index k is smaller than . Various applications of these results in the context of the two-photon realization of SU(1,1) in quantum optics are also discussed.
18649329
Generation of single-mode intelligent states and an analytic approach to their quantum statistical properties
We discuss a scheme for generation of single-mode photon states associated with the two-photon realization of the SU(1,1) algebra. This scheme is based on the process of non-degenerate down-conversion with the signal prepared initially in the squeezed vacuum state and with a measurement of the photon number in one of the output modes. We focus on the generation and properties of single-mode SU(1,1) intelligent states which minimize the uncertainty relations for Hermitian generators of the group. Properties of the intelligent states are studied by using a `weak' extension of the analytic representation in the unit disc. Then we are able to obtain exact analytical expressions for expectation values describing quantum statistical properties of the SU(1,1) intelligent states. Attention is mainly devoted to the study of photon statistics and linear and quadratic squeezing.
117834746
Proposal for a national underground science facility
The idea is explored of establishing a laboratory complex shielded from the cosmic ray flux at the earth’s surface for the purpose of housing and providing technical support for experiments in particle physics, astrophysics, and other scientific disciplines. The scientific motivation for such an underground science facility is described, and the questions of location and desired properties of the facility are discussed.
122959606
New Features of Neutrino Physics as Observed in Fermilab Exp. 1A
With the advent of large counter experiments and high energy accelerators many new phenomena have appeared in neutrino physics. Apart from the discovery of weak neutral currents [1] the most striking development has been the observation of v and v interactions with two muons in the final state [2a] (dimuon events) and more recently of v interactions with a muon and a positron in the final state [3]. Of equal importance has been the observation of departure from the scaling predictions observed in high energy v weak charged current reactions [4].
122141713
A liquid-scintillator total-absorption hadron calorimeter for the study of neutrino interactions
Abstract We describe the performance of a large-volume liquid-scintillator calorimeter which has been used to measure the total energy of hadrons produced by interactions of neutrinos with nucleons. The resolution of the calorimeter is about 12% rms for incident pions over the energy range 20–150 GeV, and about 15% for neutrino-induced hadron systems in the chosen fiducial volume after corrections for imperfect energy containment.
122869210
A possible new probe of the energy generating mechanisms of GRBs and AGN
Abstract The suggestion is made here to search for possible time and angular position correlations between energetic gamma-rays detected by the Compton Gamma-Ray Observatory and upward-going muons produced by energetic neutrino interactions in the rock surrounding the cavity in which the massive, underground neutrino detector Superkamiokande resides. The motivation and feasibility of the search are discussed.
120319912
A large-area magnetic spectrometer for the study of high-energy neutrino interactions
Abstract We describe the design, construction, and performance of a large solid iron magnetic spectrometer which has been used to i dentify and measure the momentum of muons produced by interactions of neutrinos with nucleons. The rms momentum resolution varies from 10 to 15 percent between 5 and 150 GeV/ c .