Top quark mass measurement in the tt̅ all hadronic channel using a matrix element technique in pp̅ collisions at √s=1.96 TeV

We present a measurement of the top quark mass in the all-hadronic channel (\tt $\to$ \bb$q_{1}\bar{q_{2}}q_{3}\bar{q_{4}}$) using 943 pb$^{-1}$ of \ppbar collisions at $\sqrt {s} = 1.96$ TeV collected at the CDF II detector at Fermilab (CDF). We apply the standard model production and decay matrix-element (ME) to $\ttbar$ candidate events. We calculate per-event probability densities according to the ME calculation and construct template models of signal and background. The scale of the jet energy is calibrated using additional templates formed with the invariant mass of pairs of jets. These templates form an overall likelihood function that depends on the top quark mass and on the jet energy scale (JES). We estimate both by maximizing this function. Given 72 observed events, we measure a top quark mass of 171.1 $\pm$ 3.7 (stat.+JES) $\pm$ 2.1 (syst.) GeV/$c^{2}$. The combined uncertainty on the top quark mass is 4.3 GeV/$c^{2}$.

Observation of the Ωb- baryon and measurement of the properties of the Ξb- and Ωb- baryons

We report the observation of the bottom, doubly-strange baryon Omega^-_b through the decay chain Omega^-_b -> J/psi Omega^-, where J/psi -> mu^+ mu^-, Omega^- -> Lambda K^-, and Lambda -> p pi^-, using 4.2 fb^{-1} of data from p\bar p collisions at sqrt{s}=1.96 TeV, and recorded with the Collider Detector at Fermilab. A signal is observed whose probability of arising from a background fluctuation is 4.0 * 10^{-8}, or 5.5 Gaussian standard deviations. The Omega^-_b mass is measured to be 6054.4 +/- 6.8 (stat.) +/- 0.9 (syst.) MeV/c^2. The lifetime of the Omega^-_b baryon is measured to be 1.13^{+0.53}_{-0.40}(stat.) +/- 0.02(syst.)$ ps. In addition, for the \Xi^-_b baryon we measure a mass of 5790.9 +/- 2.6(stat.) +/- 0.8(syst.) MeV/c^2 and a lifetime of 1.56^{+0.27}_{-0.25}(stat.) +/-0.02(syst.) ps. Under the assumption that the \Xi_b^- and \Omega_b^- are produced with similar kinematic distributions to the \Lambda^0_b baryon, we find sigma(Xi_b^-) B(Xi_b^- -> J/psi Xi^-)}/ sigma(Lambda^0_b) B(Lambda^0_b -> J/psi Lambda)} = 0.167^{+0.037}_{-0.025}(stat.) +/-0.012(syst.) and sigma(Omega_b^-) B(Omega_b^- -> J/psi Omega^-)/ sigma(Lambda^0_b) B(Lambda^0_b -> J/psi Lambda)} = 0.045^{+0.017}_{-0.012}(stat.) +/- 0.004(syst.) for baryons produced with transverse momentum in the range of 6-20 GeV/c.

Measurement of the b-hadron production cross section using decays to μ-D0X final states in pp̅ collisions at √s=1.96 TeV

We report a measurement of the production cross section for b hadrons in pp̅ collisions at √s=1.96  TeV. Using a data sample derived from an integrated luminosity of 83  pb-1 collected with the upgraded Collider Detector (CDF II) at the Fermilab Tevatron, we analyze b hadrons, Hb, partially reconstructed in the semileptonic decay mode Hb→μ-D0X. Our measurement of the inclusive production cross section for b hadrons with transverse momentum pT>9  GeV/c and rapidity |y|<0.6 is σ=1.30  μb±0.05  μb(stat)±0.14  μb(syst)±0.07  μb(B), where the uncertainties are statistical, systematic, and from branching fractions, respectively. The differential cross sections dσ/dpT are found to be in good agreement with recent measurements of the Hb cross section and well described by fixed-order next-to-leading logarithm predictions.

Measurement of the tt̅ production cross section in 2 fb-1 of pp̅ collisions at √s=1.96 TeV using lepton plus jets events with soft muon b tagging

We present a measurement of the tt̅ production cross section in pp̅ collisions at √s=1.96  TeV using events containing a high transverse momentum electron or muon, three or more jets, and missing transverse energy. Events consistent with tt̅ decay are found by identifying jets containing candidate heavy-flavor semileptonic decays to muons. The measurement uses a CDF run II data sample corresponding to 2  fb-1 of integrated luminosity. Based on 248 candidate events with three or more jets and an expected background of 79.5±5.3 events, we measure a production cross section of 9.1±1.6  pb.

Measurement of the b-hadron production cross section using decays to μ-D0X final states in pp̅ collisions at √s=1.96 TeV

We report a measurement of the production cross section for b hadrons in p-pbar collisions at sqrt{s}=1.96 TeV. Using a data sample derived from an integrated luminosity of 83 pb^-1 collected with the upgraded Collider Detector (CDF II) at the Fermilab Tevatron, we analyze b hadrons, H_b, partially reconstructed in the semileptonic decay mode H_b -> mu^- D^0 X. Our measurement of the inclusive production cross section for b hadrons with transverse momentum p_T > 9 GeV/c and rapidity |y|

Measurement of the tt̅ production cross section in 2 fb-1 of pp̅ collisions at √s=1.96 TeV using lepton plus jets events with soft muon b tagging

We present a measurement of the $\ttbar$ production cross section in $\ppbar$ collisions at $\sqrt{s}=1.96$ TeV using events containing a high transverse momentum electron or muon, three or more jets, and missing transverse energy. Events consistent with $\ttbar$ decay are found by identifying jets containing candidate heavy-flavor semileptonic decays to muons. The measurement uses a CDF Run II data sample corresponding to $2 \mathrm{fb^{-1}}$ of integrated luminosity. Based on 248 candidate events with three or more jets and an expected background of $79.5\pm5.3$ events, we measure a production cross section of $9.1\pm 1.6 \mathrm{pb}$.

Measurement of the Top-Quark Mass with Dilepton Events Selected Using Neuroevolution at CDF

We report a measurement of the top quark mass $M_t$ in the dilepton decay channel $t\bar{t}\to b\ell'^{+}\nu'_\ell\bar{b}\ell^{-}\bar{\nu}_{\ell}$. Events are selected with a neural network which has been directly optimized for statistical precision in top quark mass using neuroevolution, a technique modeled on biological evolution. The top quark mass is extracted from per-event probability densities that are formed by the convolution of leading order matrix elements and detector resolution functions. The joint probability is the product of the probability densities from 344 candidate events in 2.0 fb$^{-1}$ of $p\bar{p}$ collisions collected with the CDF II detector, yielding a measurement of $M_t= 171.2\pm 2.7(\textrm{stat.})\pm 2.9(\textrm{syst.})\mathrm{GeV}/c^2$.

Spectrophotometric and potentiometric investigations of copper (II)-Ethanolamine complexes - Part III. diethanolamine (Gaussian analysis of electronic spectra in mono and diethanolamine systems)

Spectrophotometric and potentiometric investigations have been carried out on copper-diethanolamine system. Job plots at 900, 900 and 580 mμ have indicated the formation of CuD++, CuD2++ and CuD3++. The n- pA curves obtained indicate the formation of CuD++, CuD2++, CuD3++, CuDOH+, CuD2OH+ and CuD3OH+. The n- pA curves have been analyzed to obtain the stability constants of these complexes. Absorption curves of pure complexes have been computed by a graphical method. Gaussian analysis of the absorption curves of pure and hydroxy complexes show the presence of a second band, indicating that the structure is that of a distorted octahedron.

A note on the measurement of travel times using bender and extender elements

By using the bender and extender elements tests, the travel times of the shear (S) and the primary (P) waves were measured for dry sand samples at different relative densities and effective confining pressures. Three methods of interpretations, namely, (i) the first time of arrival, (ii) the first peak to peak, and (iii) the cross-correlation method, were employed. All the methods provide almost a unique answer associated with the P-wave measurements. On contrary, a difference was noted in the arrival times obtained from the different methods for the S-wave due to the near field effect. The resonant column tests in the torsional mode were also performed to check indirectly the travel time of the shear wave. The study reveals that as compared to the S-wave, it is more reliable to depend on the arrival times' measurement for the P-wave. (C) 2010 Elsevier Ltd. All rights reserved.

A note on the measurement of travel times using bender and extender elements

By using the bender and extender elements tests, the travel times of the shear (S) and the primary (P) waves were measured for dry sand samples at different relative densities and effective confining pressures. Three methods of interpretations, namely, (i) the first time of arrival, (ii) the first peak to peak, and (iii) the cross-correlation method, were employed. All the methods provide almost a unique answer associated with the P-wave measurements. On contrary, a difference was noted in the arrival times obtained from the different methods for the S-wave due to the near field effect. The resonant column tests in the torsional mode were also performed to check indirectly the travel time of the shear wave. The study reveals that as compared to the S-wave, it is more reliable to depend on the arrival times’ measurement for the P-wave.

Electronic Document Management in Construction – Research Issue and Results

Electronic document management (EDM) technology has the potential to enhance the information management in construction projects considerably, without radical changes to current practice. Over the past fifteen years this topic has been overshadowed by building product modelling in the construction IT research world, but at present EDM is quickly being introduced in practice, in particular in bigger projects. Often this is done in the form of third party services available over the World Wide Web. In the paper, a typology of research questions and methods is presented, which can be used to position the individual research efforts which are surveyed in the paper. Questions dealt with include: What features should EMD systems have? How much are they used? Are there benefits from use and how should these be measured? What are the barriers to wide-spread adoption? Which technical questions need to be solved? Is there scope for standardisation? How will the market for such systems evolve?

The Electronic Journal of Information Technology in Construction (ITcon): An Open Access Journal Using an Un-paid, Volunteer-Based Organization

Introduction This case study is based on the experiences with the Electronic Journal of Information Technology in Construction (ITcon), founded in 1995. Development This journal is an example of a particular category of open access journals, which use neither author charges nor subscriptions to finance their operations, but rely largely on unpaid voluntary work in the spirit of the open source movement. The journal has, after some initial struggle, survived its first decade and is now established as one of half-a-dozen peer reviewed journals in its field. Operations The journal publishes articles as they become ready, but creates virtual issues through alerting messages to “subscribers”. It has also started to publish special issues, since this helps in attracting submissions, and also helps in sharing the work-load of review management. From the start the journal adopted a rather traditional layout of the articles. After the first few years the HTML version was dropped and papers are only published in PDF format. Performance The journal has recently been benchmarked against the competing journals in its field. Its acceptance rate of 53% is slightly higher and its average turnaround time of seven months almost a year faster compared to those journals in the sample for which data could be obtained. The server log files for the past three years have also been studied. Conclusions Our overall experience demonstrates that it is possible to publish this type of OA journal, with a yearly publishing volume equal to a quarterly journal and involving the processing of some fifty submissions a year, using a networked volunteer-based organization.

Use of Document Management Systems - a Case Study of the Finnish Construction Industry

Triggered by the very quick proliferation of Internet connectivity, electronic document management (EDM) systems are now rapidly being adopted for managing the documentation that is produced and exchanged in construction projects. Nevertheless there are still substantial barriers to the efficient use of such systems, mainly of a psychological nature and related to insufficient training. This paper presents the results of empirical studies carried out during 2002 concerning the current usage of EDM systems in the Finnish construction industry. The studies employed three different methods in order to provide a multifaceted view of the problem area, both on the industry and individual project level. In order to provide an accurate measurement of overall usage volume in the industry as a whole telephone interviews with key personnel from 100 randomly chosen construction projects were conducted. The interviews showed that while around 1/3 of big projects already have adopted the use of EDM, very few small projects have adopted this technology. The barriers to introduction were investigated through interviews with representatives for half a dozen of providers of systems and ASP-services. These interviews shed a lot of light on the dynamics of the market for this type of services and illustrated the diversity of business strategies adopted by vendors. In the final study log files from a project which had used an EDM system were analysed in order to determine usage patterns. The results illustrated that use is yet incomplete in coverage and that only a part of the individuals involved in the project used the system efficiently, either as information producers or consumers. The study also provided feedback on the usefulness of the log files.

Excited-state structures of molecules with nearby electronic states

Vibronic coupling among the nearby excited electronic states via the in-plane and the out-of-plane nuclear motions is examined in benzene, pyrazine, formaldehyde and thioformaldehyde. Results reveal that in benzene the structure distorts via the most active nuclear bending (planar) motion while in the other molecules the structures distort through an out-of-plane bending motion in their respective lowest excited states.

Electronic structures of electron donor-acceptor complexes: results from ultraviolet photoelectron spectroscopy and molecular orbital calculations

HeI photoelectron spectra of 1:1 electron donor-acceptor complexes are discussed in the light of molecular orbital calculations. The complexes discussed include those formed by BH3, BF3 and SO2. Some systematics have been found in the ionization energy shifts of the complexes compared to the free components and these are related to the strength of the donor-acceptor bond. Hel spectra of hydrogen bonded complexes are discussed in comparison with results from MO calculations. Limitations of such studies as well as scope for further investigations are indicated.