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Book Measurement of the Forward backward Asymmetry in b0 and bar u039B b0 Baryon Production in p bar p Collisions at sqrt s

Download or read book Measurement of the Forward backward Asymmetry in b0 and bar u039B b0 Baryon Production in p bar p Collisions at sqrt s written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We measure the forward-backward asymmetry in the production of ?0b and ?¯0b baryons as a function of rapidity in pp¯ collisions at √s = 1.96 TeV using 10.4 fb-1 of data collected with the D0 detector at the Fermilab Tevatron collider. The asymmetry is determined by the preference of ?0b or ?¯0b particles to be produced in the direction of the beam protons or antiprotons, respectively. As a result, the measured asymmetry integrated over rapidity y in the range 0.1

Book Forward Backward Asymmetry in Lambda b Production and Search for the Xi b and Omega b Baryons in p bar p Collisions at sqrt s

Download or read book Forward Backward Asymmetry in Lambda b Production and Search for the Xi b and Omega b Baryons in p bar p Collisions at sqrt s written by and published by . This book was released on 2015 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a search for the heavy-flavor baryons $\Xi_{b}$ (bsd) and $\Omega^{-}_{b}$ in decays $\Xi^{-}_{b}$→ J/[psi]$\Xi^{-}_{b}$ → J/[psi][Lambda][pi]-, J/[psi] → [mu]+ [mu]- and $\Omega^{-}_{b}$ → J/[psi]$\Omega^{-}_{b}$ J/[psi][Lambda] $K^{-}_{b}$, J/[psi] → [mu]+ [mu]- respectively.

Book Measurement of the Forward backward Asymmetry of Electron and Muon Pair production in Pp Collisions at sqrt s

Download or read book Measurement of the Forward backward Asymmetry of Electron and Muon Pair production in Pp Collisions at sqrt s written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents measurements from the ATLAS experiment of the forward-backward asymmetry in the reaction pp 2!Z/[gamma] * 2!l + l -, with l being electrons or muons, and the extraction of the effective weak mixing angle. The results are based on the full set of data collected in 2011 in pp collisions at the LHC at \(\sqrt{s}=7 \) TeV, corresponding to an integrated luminosity of 4.8 fb-1. The measured asymmetry values are found to be in agreement with the corresponding Standard Model predictions. The combination of the muon and electron channels yields a value of the effective weak mixing angle of sin2 [theta] eff lept =0.2308"0.0005(stat.)"0.0006(syst.)"0.0009(PDF), where the first uncertainty corresponds to data statistics, the second to systematic effects and the third to knowledge of the parton density functions. This result agrees with the current world average from the Particle Data Group fit.

Book A Precision Measurement of the Lambda c Baryon Mass

Download or read book A Precision Measurement of the Lambda c Baryon Mass written by J. C. Chen and published by . This book was released on 2005 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The {Lambda}{sub c}{sup +} baryon mass is measured using {Lambda}{sub c}{sup +} {yields} {Lambda}K{sub S}{sup 0}K{sup +} and {Lambda}{sub c}{sup +} {yields} {Sigma}{sup 0}K{sub S}{sup 0}K{sup +} decays reconstructed in 232 fb{sup -1} of data collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage ring. The {Lambda}{sub c}{sup +} mass is measured to be 2286.46 {+-} 0.14 MeV/c{sup 2}. The dominant systematic uncertainties arise from the amount of material in the tracking volume and from the magnetic field strength.

Book Centrality Dependent Strange Baryon Production in P A and Its Implications for Heavy Ion Collisions

Download or read book Centrality Dependent Strange Baryon Production in P A and Its Implications for Heavy Ion Collisions written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: BNL E910 has measured strange baryon production as a function of collision centrality for 17.5 GeV/c p-Au collisions. Collision centrality is defined by v[sub 1] the mean number projectile-nucleon interactions estimated from the ''grey'' track multiplicity. The measured[Lambda] yield increases faster than the participant scaling expectation for v[le] 3 and then saturates. A simple parameterization of this dependence applied to nucleus-nucleus collisions reproduces the measured E866 km. and WA97[Lambda] centrality dependent yields. The increase in[Lambda] production to v[le] 3 is also evident for[Lambda]s which are leading baryons, in disagreement with predictions from RQMD.

Book Measurement of the ttbar Production Cross Section in 2 Fb 1 of ppbar Collisions at sqrt s

Download or read book Measurement of the ttbar Production Cross Section in 2 Fb 1 of ppbar Collisions at sqrt s written by and published by . This book was released on 2009 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the t{bar t} production cross section in p{bar p} collisions at (square root)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 t{bar t} 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.

Book Measurement of the Inclusive Forward Backward textbf textrm t bar textrm textbf t Production Asymmetry and Its Rapidity Dependence textrm textbf dA textrm textbf fb

Download or read book Measurement of the Inclusive Forward Backward textbf textrm t bar textrm textbf t Production Asymmetry and Its Rapidity Dependence textrm textbf dA textrm textbf fb written by and published by . This book was released on 2010 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Early measurements of a large forward-background asymmetry at the CDF and D0 experiments at Fermilab have generated much recent interest, but were hampered by large uncertainties. We present here a new measurement of the parton level forward-backward asymmetry of pair-produced top quarks, using a high-statistics sample with much improved precision. We study the rapidity, y{sub top}, of the top quark production angle with respect to the incoming parton momentum in both the lab and t{bar t} rest frames. We find the parton-level forward-backward asymmetries to be A{sub fb}{sup p{bar p}} = 0.150 ± 0.050{sup stat} ± 0.024{sup syst} A{sub fb}{sup t{bar t}} = 0.158 ± 0.072{sup stat} ± 0.024{sup syst}. These results should be compared with the small p{bar p} frame charge asymmetry expected in QCD at NLO, A{sub fb} = 0.050 ± 0.015. Additionally, we introduce a measurement of the A{sub fb} rapidity dependence dA{sub fb}/d([Delta]y). We find this to be A{sub fb}{sup t{bar t}}).

Book Measurement of the Polarized Forward backward Asymmetry of Z B bar B Using a Lifetime Tag and Momentum weighted Track Charge

Download or read book Measurement of the Polarized Forward backward Asymmetry of Z B bar B Using a Lifetime Tag and Momentum weighted Track Charge written by and published by . This book was released on 1995 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a direct measurement of the parity-violating parameter A{sub b} by analyzing the left-right forward-backward asymmetry of b quarks in ee− --> Z{sup o} --> b{bar b}. The SLD experiment observes hadronic decays of Z{sup o} bosons produced at resonance in collisions of longitudinally polarized electrons and unpolarized positrons at the SLC. Heavy flavor decays of the Z{sup o} are identified by taking advantage of the long lifetime of B hadrons, the small, stable SLC beam spot, and precise tracking from SLD. The asymmetry A{sub b} is measured with a self-calibrating technique employing momentum-weighted track charge from both hemispheres in the tagged events. From our 1994--1995 sample of 3.6 pb−1 of ee− annihilation data with a luminosity-weighted average e− polarization of 77.3%, and our 1993 sample of 1.8 pb−1 with a luminosity-weighted polarization of 63.1%, we obtain A{sub b}(preliminary) = 0.843 " 0.046(stat.) " 0.051(syst.).

Book Measurement of the Lambda0 b Lifetime in Lambda0 b J psi Lambda0 in P Anti p Collisions at S 1 2

Download or read book Measurement of the Lambda0 b Lifetime in Lambda0 b J psi Lambda0 in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2006 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors report a measurement of the [Lambda]{sub b}° lifetime in the exclusive decay [Lambda]{sub b}° → J/[psi][Lambda]° in p{bar p} collisions at √s = 1.96 TeV using an integrated luminosity of 1.0 fb−1 of data collected by the CDF II detector at the Fermilab Tevatron. Using fully reconstructed decays, they measure [tau]([Lambda]{sub b}°) = 1.593{sub -0.078}{sup +0.083}(stat.) ± 0.033(syst.) ps. This is the single most precise measurement of [tau]([Lambda]{sub b}°) and is 3.2 [sigma] higher than the current world average.

Book Proton Lambda Correlations in Au Au Collisions at Square Root NN

Download or read book Proton Lambda Correlations in Au Au Collisions at Square Root NN written by and published by . This book was released on 2004 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The space-time evolution of the source of particles formed in the collision of nuclei can be studied through particle correlations. The STAR experiment is dedicated to study ultra-relativistic heavy ions collisions and allows to measure non-identical strange particle correlations. The source size can be extracted by studying p - [Lambda], {bar p} - {bar [Lambda]}, {bar p} - [Lambda] and p - {bar [Lambda]} correlation functions. Strong interaction potential has been studied for these systems using an analytical model. Final State Interaction (FSI) parameters have been determined and has shown a significant annihilation process present in {bar p} - {Lambda} and p - {bar {Lambda}} systems not present in p - {Lambda} and {bar p} - {bar {Lambda}}.

Book Multi strange Baryon Production in Au Au Collisions at Sqrt sNN

Download or read book Multi strange Baryon Production in Au Au Collisions at Sqrt sNN written by and published by . This book was released on 2003 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The transverse mass spectra and mid-rapidity yields for [Xi]s and [Omega]s plus their anti-particles are presented. The 10% most central collision yields suggest that the amount of multi-strange particles produced per produced charged hadron increases from SPS to RHIC energies. A hydrodynamically inspired model fit to the spectra, which assumes a thermalized source, seems to indicate that these multi-strange particles experience a significant transverse flow effect, but are emitted when the system is hotter and the flow is smaller than values obtained from a combined fit to [pi], K, p and [Lambda]s.