A Measurement of B-quark Fragmentation Fractions in P̄p Collisions at [centre of Mass Energy]

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Publisher : National Library of Canada = Bibliothèque nationale du Canada
ISBN 13 : 9780612413238
Total Pages : 123 pages
Book Rating : 4.4/5 (132 download)

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Book Synopsis A Measurement of B-quark Fragmentation Fractions in P̄p Collisions at [centre of Mass Energy] by : Wendy Jane Taylor

Download or read book A Measurement of B-quark Fragmentation Fractions in P̄p Collisions at [centre of Mass Energy] written by Wendy Jane Taylor and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 1999 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt:

A Measurement of B-quark Fragmentation Fractions in P¢p Collisions at [centre of Mass Energy]

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Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (133 download)

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Book Synopsis A Measurement of B-quark Fragmentation Fractions in P¢p Collisions at [centre of Mass Energy] by : Wendy Jane Taylor

Download or read book A Measurement of B-quark Fragmentation Fractions in P¢p Collisions at [centre of Mass Energy] written by Wendy Jane Taylor and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fragmentation is the process by which quarks and gluons organize themselves into hadrons. The fragmentation properties of the bottom quark cannot be predicted from fundamental principles and hence must be determined empirically. We investigate one such property, namely the flavour dependence of the fragmentation process for bottom quarks produced in 1.8-TeV proton-antiproton collisions. This flavour dependence is investigated by determining the 'B'-hadron production ratios. We use a sample of pp data corresponding to an integrated luminosity of 110 pb-1 and reconstruct the following semileptonic 'B'-hadron decays into electrons and charmed hadrons: B+[right arrow]e+neD 0X,hsp sp="0.265"B0[right arrow]e+n eD*-X , B0[right arrow]e+neD- X,hsp sp="0.265"B0s[right arrow]e +neD-s X and L0b [right arrow]e+neL- cX . With these data, we measure the ratios of fragmentation fractions fd/fuvmk id="vm1"=88± 21%, fs/fu+fdvmkr rid="vm1"= 21.5±7.1%hsp sp="0.265"and fbaryon/fu+fd vmkr rid="vm1"=12.0±4.2%. Assuming that these four hadrons saturate production of weakly-decaying ' B' hadrons, that is, that fu+fd+fs+fbaryon 1 , we determine fuvmk id="vm1"=39.8±5.4 %, fdvmkr rid="vm1"=35.2±4.8 %, fsvmkr rid="vm1"=16.1±4.5 %hsp sp="0.265"and fbaryonvmkr rid="vm1"=9.0± 2.9%. These results represent the first measurement of all four 'b'-quark fragmentation fractions in a single experiment. These fractions are in agreement both with previous phenomenological interpretations and with other experimental measurements.

A Measurement of B-quark Fragmentation Fractions in PØp Collisions at [centre of Mass Energy]

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Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (654 download)

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Book Synopsis A Measurement of B-quark Fragmentation Fractions in PØp Collisions at [centre of Mass Energy] by :

Download or read book A Measurement of B-quark Fragmentation Fractions in PØp Collisions at [centre of Mass Energy] written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Measurement of the Top Quark Mass Using Charged Particles in Pp Collisions at {u221A}s

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Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (16 download)

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Book Synopsis Measurement of the Top Quark Mass Using Charged Particles in Pp Collisions at {u221A}s by :

Download or read book Measurement of the Top Quark Mass Using Charged Particles in Pp Collisions at {u221A}s written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel technique for measuring the mass of the top quark that uses only the kinematic properties of its charged decay products is presented. Top quark pair events with final states with one or two charged leptons and hadronic jets are selected from the data set of 8 TeV proton-proton collisions, corresponding to an integrated luminosity of 19.7 fb-1. By reconstructing secondary vertices inside the selected jets and computing the invariant mass of the system formed by the secondary vertex and an isolated lepton, an observable is constructed that is sensitive to the top quark mass that is expected to be robust against the energy scale of hadronic jets. The main theoretical systematic uncertainties, concerning the modeling of the fragmentation and hadronization of b quarks and the reconstruction of secondary vertices from the decays of b hadrons, are studied. A top quark mass of 173.68±0.20(stat)-0.97+1.58(syst) GeV is measured. Furthermore, the overall systematic uncertainty is dominated by the uncertainty in the b quark fragmentation and the modeling of kinematic properties of the top quark.

Determination of the Ratio of B-quark Fragmentation Fractions Fs/fd in Pp Collisions at S

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Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (16 download)

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Book Synopsis Determination of the Ratio of B-quark Fragmentation Fractions Fs/fd in Pp Collisions at S by :

Download or read book Determination of the Ratio of B-quark Fragmentation Fractions Fs/fd in Pp Collisions at S written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: With an integrated luminosity of 2.47 fb-1 recorded by the ATLAS experiment at the LHC, the exclusive decays B0s→J/?? and B0d→J/?K*0 of B mesons produced in pp collisions at √s=7 TeV are used to determine the ratio of fragmentation fractions fs/fd. From the observed B0s→J/?? and B0d→J/?K*0 yields, the quantity (fs/fd)[B(B0s→J/??)/B(B0d→J/?K*0)] is measured to be 0.199±0.004(stat)±0.008(syst). Using a recent theory prediction for [B(B0s→J/??)/B(B0d→J/?K*0)] yields (fs/fd)=0.240±0.004(stat)±0.010(syst)±0.017(th). As a result, it is based on a new approach that provides a significant improvement of the world average.

Measurement of the Relative Fragmentation Fractions of B-bar Hadrons

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Publisher :
ISBN 13 :
Total Pages : 169 pages
Book Rating : 4.:/5 (316 download)

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Book Synopsis Measurement of the Relative Fragmentation Fractions of B-bar Hadrons by : Karen Ruth Gibson

Download or read book Measurement of the Relative Fragmentation Fractions of B-bar Hadrons written by Karen Ruth Gibson and published by . This book was released on 2006 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes the first Run II measurement of b quark fragmentation into {bar B}{sup 0}, B{sup -}, and {bar B}{sub s}{sup 0} mesons and {Lambda}{sub b}{sup 0} baryons using semileptonic B decays. The result is based on 360 pb{sup -1} of data collected with the CDF detector in p{bar p} collisions at {radical}s = 1,960 GeV at the Tevatron Collider at Fermilab. The fragmentation fractions are measured for an effective {bar B} hadron p{sub T} threshold of 7 GeV/c to be f{sub u}/f{sub d} = 1.054 {+-} 0.018(stat){sub -0.045}{sup +0.025}(syst) {+-} 0.058(BR), f{sub s}/(f{sub u} + f{sub d}) = 0.160 {+-} 0.005(stat){sub -0.010}{sup +0.011}(syst){sub -0.034}{sup +0.057}(BR), and f{sub {Lambda}{sub b}}/(f{sub u} + f{sub d}) = 0.281 {+-} 0.012(stat){sub -0.056}{sup +0.058}(syst){sub -0.086}{sup +0.128}(BR). f{sub s}/(f{sub u} + f{sub d}) agrees both with previous CDF measurements and the world averages, dominated by the LEP measurements, with {approx} 1{sigma}. However, f{sub {Lambda}{sub b}}/(f{sub u} + f{sub d}) is approximately twice the value which has been measured at LEP and in CDF Run I and disagrees with the LEP results by approximately 2 {sigma}.

Measurement of the T T-bar Production Cross Section in Pp Collisions at 7 TeV in Lepton + Jets Events Using B-quark Jet Identification

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Publisher :
ISBN 13 :
Total Pages : 39 pages
Book Rating : 4.:/5 (16 download)

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Book Synopsis Measurement of the T T-bar Production Cross Section in Pp Collisions at 7 TeV in Lepton + Jets Events Using B-quark Jet Identification by :

Download or read book Measurement of the T T-bar Production Cross Section in Pp Collisions at 7 TeV in Lepton + Jets Events Using B-quark Jet Identification written by and published by . This book was released on 2011 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new measurement of the inclusive production cross section for pp to t t-bar is performed at a center-of-mass energy of 7 TeV using data collected by the CMS experiment at the LHC. The analysis uses a data sample corresponding to an integrated luminosity of 36 inverse picobarns, and is based on the final state with one isolated, high transverse momentum muon or electron, missing transverse energy, and hadronic jets. The ttbar content of the selected events is enhanced by requiring the presence of at least one jet consistent with b-quark hadronization. The measured cross section is 150 +/- 9 (stat.) +/- 17 syst.) +/- 6 (lumi.) pb and is in agreement with higher-order QCD calculations. The combination of this measurement with a previous CMS result based on dileptons gives 154 +/- 17 (stat.+syst.) +/- 6 (lumi.) pb.

Inclusive b Jet Production in Proton-Proton Collisions

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Publisher : Springer Nature
ISBN 13 : 3030343839
Total Pages : 325 pages
Book Rating : 4.0/5 (33 download)

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Book Synopsis Inclusive b Jet Production in Proton-Proton Collisions by : Patrick L.S. Connor

Download or read book Inclusive b Jet Production in Proton-Proton Collisions written by Patrick L.S. Connor and published by Springer Nature. This book was released on 2019-11-29 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: ^ 74 GeV and |y| 2.4; the b jets must contain a B hadron. The measurement has significant statistics up to p T ∼ O(TeV). Advanced methods of unfolding are performed to extract the signal. It is found that fixed-order calculations with underlying event describe the measurement well.

Measurement of the Top Quark Pair Production Cross Section in Pp Collisions at a Center-of-mass Energy of 7 TeV with the CMS Experiment at the LHC

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Publisher :
ISBN 13 :
Total Pages : 140 pages
Book Rating : 4.:/5 (778 download)

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Book Synopsis Measurement of the Top Quark Pair Production Cross Section in Pp Collisions at a Center-of-mass Energy of 7 TeV with the CMS Experiment at the LHC by : Geng-Yuan Jeng

Download or read book Measurement of the Top Quark Pair Production Cross Section in Pp Collisions at a Center-of-mass Energy of 7 TeV with the CMS Experiment at the LHC written by Geng-Yuan Jeng and published by . This book was released on 2011 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: We perform a measurement of the top quark pair production cross section in pp collisions at a center-of-mass energy of 7 TeV at the Large Hadron Collider. The analysis is based on a 36 pb -1 dataset collected with the CMS experiment in 2010. We study the kinematic characteristics of events with exactly one isolated muon in association with additional hard jets and exhibiting substantial missing transverse energy to distinguish the tt− signal from the electroweak and QCD multijet backgrounds. The tt− signal is extracted by simultaneously fitting the tri-jet invariant mass distributions in events with exactly three jets and at least four jets. The measured cross section is 157 ± 12(stat.[Special characters omitted.] (syst.) ± 6(lumi.) pb, which is consistent with the theoretical predictions.

Statistics and Analysis of Scientific Data

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Publisher : Springer
ISBN 13 : 1493965727
Total Pages : 323 pages
Book Rating : 4.4/5 (939 download)

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Book Synopsis Statistics and Analysis of Scientific Data by : Massimiliano Bonamente

Download or read book Statistics and Analysis of Scientific Data written by Massimiliano Bonamente and published by Springer. This book was released on 2016-11-08 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: The revised second edition of this textbook provides the reader with a solid foundation in probability theory and statistics as applied to the physical sciences, engineering and related fields. It covers a broad range of numerical and analytical methods that are essential for the correct analysis of scientific data, including probability theory, distribution functions of statistics, fits to two-dimensional data and parameter estimation, Monte Carlo methods and Markov chains. Features new to this edition include: • a discussion of statistical techniques employed in business science, such as multiple regression analysis of multivariate datasets. • a new chapter on the various measures of the mean including logarithmic averages. • new chapters on systematic errors and intrinsic scatter, and on the fitting of data with bivariate errors. • a new case study and additional worked examples. • mathematical derivations and theoretical background material have been appropriately marked, to improve the readability of the text. • end-of-chapter summary boxes, for easy reference. As in the first edition, the main pedagogical method is a theory-then-application approach, where emphasis is placed first on a sound understanding of the underlying theory of a topic, which becomes the basis for an efficient and practical application of the material. The level is appropriate for undergraduates and beginning graduate students, and as a reference for the experienced researcher. Basic calculus is used in some of the derivations, and no previous background in probability and statistics is required. The book includes many numerical tables of data, as well as exercises and examples to aid the readers' understanding of the topic.

Measurement of the Mass Difference Between Top Quark and Antiquark in Pp Collisions at Sqrt(s)

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (967 download)

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Book Synopsis Measurement of the Mass Difference Between Top Quark and Antiquark in Pp Collisions at Sqrt(s) by :

Download or read book Measurement of the Mass Difference Between Top Quark and Antiquark in Pp Collisions at Sqrt(s) written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The invariance of the standard model (SM) under the CPT transformation predicts equality of particle and antiparticle masses. This prediction is tested by measuring the mass difference between the top quark and antiquark (Delta m[t] = m[t] - m[t-bar]) that are produced in pp collisions at a center-of-mass energy of 8 TeV, using events with a muon or an electron and at least four jets in the final state. The analysis is based on data corresponding to an integrated luminosity of 19.6 inverse-femtobarns collected by the CMS experiment at the LHC, and yields a value of Delta m[t] = -0.15 +/- 0.19 (stat) +/- 0.09 (syst) GeV, which is consistent with the SM expectation. This result is significantly more precise than previously reported measurements.

Studies of Two Particle Correlation Functions and Photon-tagged Jet Fragmentation in PbPb and Pp Collisions with CMS at the LHC

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Publisher :
ISBN 13 :
Total Pages : 113 pages
Book Rating : 4.:/5 (12 download)

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Book Synopsis Studies of Two Particle Correlation Functions and Photon-tagged Jet Fragmentation in PbPb and Pp Collisions with CMS at the LHC by : Dragos Alexandru Velicanu

Download or read book Studies of Two Particle Correlation Functions and Photon-tagged Jet Fragmentation in PbPb and Pp Collisions with CMS at the LHC written by Dragos Alexandru Velicanu and published by . This book was released on 2017 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis studies of two particle correlations in proton-proton (pp), proton-lead (pPb), and lead-lead (PbPb) collisions, as well as jet fragmentation functions for jets paired with an isolated prompt photon in pp and PbPb collisions to better understand matter in a Quark Gluon Plasma (QGP) state. The correlation studies measure the precise hydrodynamic behavior of PbPb collisions through a Fourier analysis of charged particles emitted from the QGP and show unexpectedly strong collective behavior in high multiplicity pp and pPb collisions. The photon-tagged jet studies provide tight constraints for understanding the interactions between the jet and the Quark Gluon Plasma it traverses by both measuring the jet substructure properties via the fragmentation function, and having a sample of jets unbiased by the interactions we are trying to probe by selecting high energy photon events. These analyses are performed using data recorded by the CMS experiment at the LHC from PbPb, pPb, and pp collisions at a center of mass energy of 5.02 TeV per nucleon-nucleon pair, as well as 2.76 TeV PbPb collisions and 7 TeV pp collisions in the correlation analyses.

Measurement of the Top Quark Mass in P Anti-p Collisions at S**1/2

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Publisher :
ISBN 13 :
Total Pages : 23 pages
Book Rating : 4.:/5 (873 download)

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Book Synopsis Measurement of the Top Quark Mass in P Anti-p Collisions at S**1/2 by :

Download or read book Measurement of the Top Quark Mass in P Anti-p Collisions at S**1/2 written by and published by . This book was released on 2006 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report the first measurement of the top quark mass using the decay length technique in p{bar p} collisions at a center-of-mass energy of 1.96 TeV. This technique uses the measured flight distance of the b hadron to infer the mass of the top quark in lepton plus jets events with missing transverse energy. It relies solely on tracking and avoids the jet energy scale uncertainty that is common to all other methods used so far. We apply our novel method to a 695 pb−1 data sample recorded by the CDF II detector at Fermilab and extract a measurement of m{sub t} = 180.7{sub -13.4}{sup +15.5}(stat.) ± 8.6 (syst.) GeV/c2. While the uncertainty of this result is larger than that of other measurements, the dominant uncertainties in the decay length technique are uncorrelated with those in other methods. This result can help reduce the overall uncertainty when combined with other existing measurements of the top quark mass.

Measurement of the Top Quark Mass in P Anti-p Collisions at S**ư

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Publisher :
ISBN 13 :
Total Pages : 23 pages
Book Rating : 4.:/5 (16 download)

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Book Synopsis Measurement of the Top Quark Mass in P Anti-p Collisions at S**ư by :

Download or read book Measurement of the Top Quark Mass in P Anti-p Collisions at S**ư written by and published by . This book was released on 2006 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report the first measurement of the top quark mass using the decay length technique in p{bar p} collisions at a center-of-mass energy of 1.96 TeV. This technique uses the measured flight distance of the b hadron to infer the mass of the top quark in lepton plus jets events with missing transverse energy. It relies solely on tracking and avoids the jet energy scale uncertainty that is common to all other methods used so far. We apply our novel method to a 695 pb−1 data sample recorded by the CDF II detector at Fermilab and extract a measurement of m{sub t} = 180.7{sub -13.4}{sup +15.5}(stat.) ± 8.6 (syst.) GeV/c2. While the uncertainty of this result is larger than that of other measurements, the dominant uncertainties in the decay length technique are uncorrelated with those in other methods. This result can help reduce the overall uncertainty when combined with other existing measurements of the top quark mass.

Measurement of Ratios of Fragmentation Fractions for Bottom Hadrons in P Anti-p Collisions at S**ư

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Publisher :
ISBN 13 :
Total Pages : 54 pages
Book Rating : 4.:/5 (16 download)

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Book Synopsis Measurement of Ratios of Fragmentation Fractions for Bottom Hadrons in P Anti-p Collisions at S**ư by :

Download or read book Measurement of Ratios of Fragmentation Fractions for Bottom Hadrons in P Anti-p Collisions at S**ư written by and published by . This book was released on 2008 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Measurement of the Forward-Backward Asymmetry in Low-Mass Bottom-Quark Pairs Produced in Proton-Antiproton Collisions

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (951 download)

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Book Synopsis Measurement of the Forward-Backward Asymmetry in Low-Mass Bottom-Quark Pairs Produced in Proton-Antiproton Collisions by :

Download or read book Measurement of the Forward-Backward Asymmetry in Low-Mass Bottom-Quark Pairs Produced in Proton-Antiproton Collisions written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report a measurement of the forward-backward asymmetry, $A_{FB}$, in $b\bar{b}$ pairs produced in proton-antiproton collisions and identified by muons from semileptonic $b$-hadron decays. The event sample was collected at a center-of-mass energy of $\sqrt{s}=1.96$ TeV with the CDF II detector and corresponds to 6.9 fb$^{-1}$ of integrated luminosity. We obtain an integrated asymmetry of $A_{FB}(b\bar{b})=(1.2 \pm 0.7)$\% at the particle level for $b$-quark pairs with invariant mass, $m_{b\bar{b}}$, down to $40$ GeV/$c^2$ and measure the dependence of $A_{FB}(b\bar{b})$ on $m_{b\bar{b}}$. The results are compatible with expectations from the standard model.

Measurement of the Top Quark Pair Production Cross Section and an In-situ B-tagging Efficiency Calibration with ATLAS in Pp Collisions at √s

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Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (133 download)

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Book Synopsis Measurement of the Top Quark Pair Production Cross Section and an In-situ B-tagging Efficiency Calibration with ATLAS in Pp Collisions at √s by : Bin Guo

Download or read book Measurement of the Top Quark Pair Production Cross Section and an In-situ B-tagging Efficiency Calibration with ATLAS in Pp Collisions at √s written by Bin Guo and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the top anti-top quark (ttbar)production cross section in the dilepton final states from proton-proton collisions at a center of mass energy at 7 TeV at the LHC. A b-tagging algorithm based on tracks displaced from the event interaction vertex is applied to identify bottom quark jets from top quark decay and reject background events. Given the relatively pure sample of bottom quark jets in ttbar dilepton final states, a new technique to measure in-situ the b-tagging efficiency is introduced that uses the distribution of the number of observed b-tagged jets. We present results with data collected at the ATLAS detector in 2010 with an integrated luminosity of 35 pb-1. The measured ttbar cross section is 176 +22/-21 (stat.) ± 20 (syst.) ± 6 (lum.) pb in the dilepton channel. We will also discuss the future prospects of this measurement.