451 research outputs found
The problem of equilibration and the computation of correlation functions on a quantum computer
We address the question of how a quantum computer can be used to simulate
experiments on quantum systems in thermal equilibrium. We present two
approaches for the preparation of the equilibrium state on a quantum computer.
For both approaches, we show that the output state of the algorithm, after long
enough time, is the desired equilibrium. We present a numerical analysis of one
of these approaches for small systems. We show how equilibrium
(time)-correlation functions can be efficiently estimated on a quantum
computer, given a preparation of the equilibrium state. The quantum algorithms
that we present are hard to simulate on a classical computer. This indicates
that they could provide an exponential speedup over what can be achieved with a
classical device.Comment: 25 pages LaTex + 8 figures; various additional comments, results and
correction
Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events
The - oscillation frequency has been measured with a sample of
23 million \B\bar B pairs collected with the BABAR detector at the PEP-II
asymmetric B Factory at SLAC. In this sample, we select events in which both B
mesons decay semileptonically and use the charge of the leptons to identify the
flavor of each B meson. A simultaneous fit to the decay time difference
distributions for opposite- and same-sign dilepton events gives ps.Comment: 7 pages, 1 figure, submitted to Physical Review Letter
Tear production, intraocular pressure and conjunctival microbiota, cytology and histology of New Zealand rabbits (Oryctolagus cuniculus)
Relations between Financing and Output in the Not-for-Profit Hospital
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68639/2/10.1177_107755878804500204.pd
Leaf anatomy of Qualea parviflora (Vochysiaceae) in three phytophysiognomies of the Mato Grosso State, Brazil
Effects of ethyl-cyanoacrylate and octyl-cyanoacrylate on experimental corneal lesions in rabbits
A comparative analysis of foliar chemical composition and leaf construction costs of beech (Fagus sylvatica L.), sycamore maple (Acer pseudoplatanus L.) and ash (Fraxinus excelsior L.) saplings along a light gradient
Determination of the Form Factors for the Decay B0 --> D*-l+nu_l and of the CKM Matrix Element |Vcb|
We present a combined measurement of the Cabibbo-Kobayashi-Maskawa matrix element and of the parameters , , and , which fully characterize the form factors of the decay in the framework of HQET, based on a sample of about 52,800 decays recorded by the BABAR detector. The kinematical information of the fully reconstructed decay is used to extract the following values for the parameters (where the first errors are statistical and the second systematic): , , , . By combining these measurements with the previous BABAR measurements of the form factors which employs a different technique on a partial sample of the data, we improve the statistical accuracy of the measurement, obtaining: and Using the lattice calculations for the axial form factor , we extract , where the third error is due to the uncertainty in
Study of the Exclusive Initial-State Radiation Production of the System
A study of exclusive production of the system through initial-state r adiation is performed in a search for charmonium states, where or . The mesons are reconstructed in the , , and decay modes. The is reconstructed through the decay mode. The analysis makes use of an integrated luminosity of 288.5 fb collected by the BaBar experiment. The mass spectrum shows a clear signal. Further structures appear in the 3.9 and 4.1 GeV/ regions. No evidence is found for Y(4260) decays to , implying an up per limit \frac{\BR(Y(4260)\to D \bar D)}{\BR(Y(4260)\to J/\psi \pi^+ \pi^-)} < 7.6 (95 % confidence level)
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