Programmed discrimination of qbits with added classical information

We investigate some properties of programmed quantum-state discriminators with simple programs. Bergou et al. [Phys. Rev. A 73, 062334 (2006)] have considered programmable devices which are supplied with two distinct but unknown program qbits and one data qbit which is certain to be identical to one or other of the program qbits. The task is to discriminate between the first and the second possibility. In this paper, we consider this state-discrimination problem when there is some additional classical information available. We find that in the minimum error discrimination mode, the probability of correct discrimination is increased by each type of classical information. The same is broadly true of unambiguous discrimination, with the chance of success improving when the overlap between the program qbits is reduced.     

Search for new heavy particles in the WZ0 final state in pp collisions at square root[s] = 1.8 TeV

We present the first general search for new heavy particles, X, which decay via X --> WZ0 --> e(nu)+jj as a function of M(X) and Gamma(X) in pp collisions at square root[s] = 1.8 TeV. No evidence is found for production of X in 110 pb(-1) of data collected by the Collider Detector at Fermilab. General cross section limits are set at the 95% C.L. as a function of mass and width of the new particle. The results are further interpreted as mass limits on the production of new heavy charged vector bosons which decay via W' --> WZ0 in an extended gauge model as a function of the width, Gamma(W'), and mixing factor between the W' and the standard model W bosons.     

Some Optimization Problems with Bulk-Service Queues

An optimal control problem for a single bulk-service queue is considered. Theorems that characterize the optimal control strategy in some circumstances are proved; they complement earlier results by Deb and Serfozo for a comparable problem. Most of the analysis uses direct probabilistic reasoning rather than specialized methods such as dynamic programming. Some illustrative examples are presented.     

On the existence of surface wave solutions in piezoelectric crystals an example of non-existence

According to general theory, a semi-infinite piezoelectric crystal with mechanically free surface and an adjoining medium with zero dielectric constant, may or may not allow a surface wave solution. Examples where surface wave solutions are not allowed, are not known, and one might think that solutions actually always exist. In the present paper this problem is put to rest by an explicit example of non-existence.     

Search for the ρρ enhancement near 1700 MeV/c in the reaction at 8.3 GeV/c

Results are presented from a search for a ρ⁰ρ⁰ enhancement in antiproton annihilations. A ρ⁰ρ⁰ resonance was recently observed in radiative ψ decays, and its existence has been supported by the results of an antiproton experiment at 5.7 GeV/c. No indication of this ρ⁰ρ⁰ enhancement is seen is our data, in direct contradiction with the earlier, lower statistics experiment.     

Measurement of charged-particle multiplicities in gluon and quark jets in pp collisions at square root of s = 1.8 TeV

We report the first largely model independent measurement of charged particle multiplicities in quark and gluon jets, Nq and Ng, produced at the Fermilab Tevatron in pp collisions with a center-of-mass energy of 1.8 TeV and recorded by the Collider Detector at Fermilab. The measurements are made for jets with average energies of 41 and 53 GeV by counting charged particle tracks in cones with opening angles of theta(c) = 0.28, 0.36, and 0.47 rad around the jet axis. The corresponding jet hardness Q = Ejet theta c varies in the range from 12 to 25 GeV. At Q = 19.2 GeV, the ratio of multiplicities r = Ng/Nq is found to be 1.64+/-0.17, where statistical and systematic uncertainties are added in quadrature. The results are in agreement with resummed perturbative QCD calculations.     

Search for [corrected] B0(s) --> mu+ mu- and B0(d) [corrected] --> mu + mu- decays in pp collisions with CDF II

We report on a search for B0(s) --> mu+ mu- and B0(d) --> mu + mu- decays in pp collisions at square root(s) = 1.96 TeV using 364 pb(-1) of data collected by the CDF II detector at the Fermilab Tevatron Collider. After applying all selection requirements, we observe no candidates inside the B0(s) or B0(d) mass windows. The resulting upper limits on the branching fractions are B(B0(s) --> mu+ mu-) < 1.5 x 10(-7) and B(B0(d) --> mu+ mu-) < 3.9 x 10(-8) at 90% confidence level.     

Search for long-lived doubly charged Higgs bosons in pp collisions at sqrt[s] = 1.96 TeV

We present a search for long-lived doubly charged Higgs bosons (H(+/- +/-)), with signatures of high ionization energy loss and muonlike penetration. We use 292 pb(-1) of data collected in pp collisions at sqrt[s] = 1.96 TeV by the CDF II detector at the Fermilab Tevatron. Observing no evidence of long-lived doubly charged particle production, we exclude H(+/- +/-)(L) and H(+/- +/-)(R) bosons with masses below 133 GeV/c(2) and 109 GeV/c(2), respectively. In the degenerate case we exclude H(+/- +/-) mass below 146 GeV/c(2). All limits are quoted at the 95% confidence level.