Download or read book Measurement of the B0s Lifetime Using Semi leptonic Decays with the Collider Detector at Fermilab written by Chun Yang and published by . This book was released on 2007 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Vol misc inscr Petitionen betr Getreidez lle 1887 88 written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the 0b Lifetime in 0b u2192 c Decays at the Collider Detector at Fermilab written by and published by . This book was released on 2008 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: The lifetime of the ?0b baryon (consisting of u, d and b quarks) is the theoretically most interesting of all b-hadron lifetimes. The lifetime of ?0b probes our understanding of how baryons with one heavy quark are put together and how they decay. Experimentally however, measurements of the ?0b lifetime have either lacked precision or have been inconsistent with one another. This thesis describes the measurement of ?0b lifetime in proton-antiproton collisions with center of mass energy of 1.96 TeV at Fermilab's Tevatron collider. Using 1070 ± 60pb-1 of data collected by the Collider Detector at Fermilab (CDF), a clean sample of about 3,000 fully-reconstructed ?0b →?c+?- decays (with ?+c subsequently decaying via ?+c → p+ K- ?+) is used to extract the lifetime of the ?0b baryon, which is found to be c?(?0b) = 422.8 ± 13.8(stat) ± 8.8(syst)?m. This is the most precise measurement of its kind, and is even better than the current world average. It also settles the recent controversy regarding the apparent inconsistency between CDF's other measurement and the rest of the world.

Download or read book B lifetime Measurements at CDF written by and published by . This book was released on 1993 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The average b-hadron lifetime has been measured using a high statistics sample of B → J/?X decays recorded with the Collider Detector at Fermilab. The decay vertices of J/? →??− candidates have been reconstructed using information from a silicon vertex-detector. The measured B lifetime, which is the average over all b-hadrons produced in p{bar p} collisions at √s = 1.8 TeV, weighted by their branching ratios into J/? is:?B = 1.46 ± 0.06(stat.) ± 0.06(sys.)ps (preliminary); In addition we used the fully reconstructed final states B{sup ±} → J/?K{sup ±} and B° → J/?K°* to measure the exclusive lifetime of charged and neutral B-mesons. We measure:?{sub B}{sup ±} = 1.59 ± 0.27(stat.) ± 0.17(sys.) ps (preliminary);?{sub B}° = 1. 34 ± 0.31 (stat.) {plus_minus} 0.17 (sys.) ps (preliminary); From this we obtain the following result for the lifetime ratio:?{sub B}{sup {plus_minus}}/? {sub B}° = 1.19 {plus_minus} 0.35(stat.) {plus_minus} 0.12(sys.) (preliminary); This represents the first measurements of the b-lifetime at a hadron collider.

Download or read book Measurement of the Lambda 0b Lifetime in Lambda 0b 2 Lambda c pi Decays at the Collider Detector at Fermilab written by and published by . This book was released on 2008 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: The lifetime of the [Lambda]0b baryon (consisting of u, d and b quarks) is the theoretically most interesting of all b-hadron lifetimes. The lifetime of [Lambda]0b probes our understanding of how baryons with one heavy quark are put together and how they decay. Experimentally however, measurements of the [Lambda]0b lifetime have either lacked precision or have been inconsistent with one another. This thesis describes the measurement of [Lambda]0b lifetime in proton-antiproton collisions with center of mass energy of 1.96 TeV at Fermilab's Tevatron collider. Using 1070 ± 60pb-1 of data collected by the Collider Detector at Fermilab (CDF), a clean sample of about 3,000 fully-reconstructed [Lambda]0b →[Lambda]c+[pi]- decays (with [Lambda]+c subsequently decaying via [Lambda]+c → p+ K- [pi]+) is used to extract the lifetime of the [Lambda]0b baryon, which is found to be c[tau]([Lambda]0b) = 422.8 ± 13.8(stat) ± 8.8(syst)[mu]m. This is the most precise measurement of its kind, and is even better than the current world average. It also settles the recent controversy regarding the apparent inconsistency between CDF's other measurement and the rest of the world.

Download or read book Measurement of the B0s Lifetime Using the Semileptonic Decay Channel B0s u2192 D s vX written by and published by . This book was released on 2009 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report a measurement of the B0s lifetime in the semileptonic decay channel BB0s → D-s?+vX (and its charge conjugate), using approximately 0.4 fb-1 of data collected with the DØ detector during 2002–2004. Using 5176 reconstructed D-s ?+ signal events, we have measured the B0s lifetime to be ? (B0s) = 1.398 ± 0.044 (stat)+0.028 -0.025 (syst) ps. This is the most precise measurement of the B0s lifetime to date.

Download or read book Measuring the B Lifetime Using Inclusive Jpsi at Cdf written by Hans Wenzel and published by LAP Lambert Academic Publishing. This book was released on 2010-11 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes the measurement of the average B hadron lifetime using a high statistics sample of B--> J/psi X decays produced in proton antiproton collisions at a center of mass energy of 1.8 TeV at the Fermilab Tevatron. The integrated luminosity of the sample is 10.1 pb-1 recorded with the Collider Detector at Fermilab (CDF). In this analysis the decay vertex of the decay J/psi -->mu^+ mu^-$ as reconstructed by a silicon vertex detector is used to extract the lifetime from the data. We find the following value for the average b hadron lifetime: [ tau_{B} = 1.46 pm 0.06; (stat.); pm 0.06; (syst.); ps] This is the first measurement of the b-hadron lifetime at a hadron collider. It demonstrates that it is possible to access the large b-quark production cross section in $poverline{p}$ collisions and to achieve high statistics even in modes which have small product branching ratios as in this case: $BR(Brightarrow J/psi X) cdot BR(J/psi rightarrow mu^+ mu^-) = 7.7 times 10^{-4}$.

Download or read book Measurement of the B0s Lifetime Using the Semileptonic Decay Channel B0s 2 D s mu vX written by and published by . This book was released on 2009 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report a measurement of the B0s lifetime in the semileptonic decay channel BB0s → D-s[mu]+vX (and its charge conjugate), using approximately 0.4 fb-1 of data collected with the DØ detector during 2002-2004. Using 5176 reconstructed D-s [mu]+ signal events, we have measured the B0s lifetime to be [tau] (B0s) = 1.398 ± 0.044 (stat)+0.028 -0.025 (syst) ps. This is the most precise measurement of the B0s lifetime to date.

Download or read book Measurement of the Inclusive B Lifetime Using rm J psi s at the CDF Experiment written by and published by . This book was released on 1993 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of Lifetime and Decay Width Difference in B0s J psi Phi Decays written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors measure the mean lifetime, [tau] = 2/([Lambda]{sub L} + [Lambda]{sub H}), and the decay-width difference, [Delta][Lambda] = [Lambda]{sub L} - [Lambda]{sub H}, of the light and heavy mass eigenstates of the B{sub s}° meson, B{sub sL}° and B{sub sH}°, in B{sub s}° → J/[psi][phi] decays using 1.7 fb−1 of data collected with the CDF II detector at the Fermilab Tevatron p{bar p} collider. Assuming CP conservation, a good approximation for the B{sub s}° system in the standard model, they obtain [Delta][Lambda] = 0.076{sub -0.063}{sup +0.059}(stat.) ± 0.006(syst.) ps−1 and [tau] = 1.52 ± 0.04(stat.) ± 0.02(syst.) ps, the most precise measurements to date. The constraints on the weak phase and [Delta][Lambda] are consistent with CP conservation.

Download or read book Measurement of the B c Meson Lifetime Using B c J psi E Nu e written by and published by . This book was released on 2006 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present a measurement of the B{sub c} meson lifetime in the semileptonic decay mode B{sub c}+ → J/?e+?{sub e} using the CDF II detector at the Fermilab Tevatron Collider. From a sample of about 360 pb−1 of p{bar p} collisions at √s = 1.96 TeV, they reconstruct J/?e+ pairs with invariant mass in the kinematically allowed range 4

Download or read book Measurement of B0 and B Lifetimes Using Semileptonic Decays at CDF written by and published by . This book was released on 2010 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lifetime measurements for B0 and B+ are presented using semileptonic decays of B mesons from 360 pb-1 of data collected by CDF's lepton plus displaced track trigger. The decays B 2!l[nu]DX, where D is either D +, D0, or D* +, are partially reconstructed from a muon or electron, a displaced track, and a fully reconstructed charm meson. The B 0 and B+ lifetimes are obtained from an unbinned maximum-likelihood fit to the proper decay length distributions. The measured lifetimes are [tau]B 0 = 1.527 ± 0.012(stat.) ± 0.023(syst.)ps and [tau]B + = 1.629 ± 0.013(stat.) ± 0.025(syst.)ps.

Download or read book B Lifetimes at CDF written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of the average b-hadron lifetime using inclusive B [yields] J/[psi]X events, the individual B[sub u] and B[sub d] lifetimes and their ratio using exclusive B [yields] [psi]K events, and the B[sub s] lifetime using semileptonic B[sub s] lifetime using semileptonic B[sub s] [yields] l[nu]D[sub 3]X events are presented. The results were obtained from a 21.3 pb[sup [minus]1] sample of [radical]s = 1.8 TeV [bar p]p collisions collected in 1992--93 at the Fermilab Tevatron collider and required the precise position measurements of the recently installed CDF silicon vertex detector.

Download or read book Measurement of the Lifetime of the B sup O sub S Meson from D sub S l sup Plus Correlations written by and published by . This book was released on 1996 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The lifetime of the B{sub s}° meson is measured using the semileptonic decay B{sub s}° → D{sub s}−l{sup {plus}}[nu]X. The data sample consists of approximately 110 pb−1 of p{ovr p} collisions at √s = 1.8 TeV collected by the CDF detector at the Fermilab Tevatron collider. There are 254±21 D{sub s}−l{sup {plus}} signal events where the D{sub s}{sup {plus}} is reconstructed through its decay mode D{sub s}− → [phi][pi]−, [phi] → K{sup {plus}}K−. Using these events, the B{sub s}° meson lifetime is determined to be [tau](B{sub s}°) = 1.37{sup {plus}0.14}{sub -0.12}(stat.)±0.04(syst.) ps. The B{sub s}° meson proper decay length distribution has been examined for a lifetime difference between the two CP eigenstates of the B{sub s}° meson, B{sub s}{sup H} and B{sub s}{sup L}. 12 refs., 3 figs., 1 tab.

Download or read book Measurement of the B Cross Section at CDF Via B Semileptonic Decays written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Lambda 0 b Lifetime in the Exclusive Decay Lambda 0 b rightarrow J psi Lambda 0 with the D0 detector written by and published by . This book was released on 2012 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work we report a measurement of the [Lambda]0b baryon lifetime using the exclusive decay [Lambda]0b→ J/ [Psi][Lambda]0. The B0 meson lifetime is also measured in the topologically similar channel B0→ J/ K0S , which provides a crosscheck of the measurement procedure, and allows a direct determination of the ratio of the [Lambda]0b and the B0 lifetimes. The data used in this analysis were collected with the DØ detector during the complete Run II of the Fermilab Tevatron Collider, from 2002 to 2011, and correspond to an integrated luminosity of 10.4 fb-1 of proton-antiproton collisions at a center of mass energy √s = 1.96 TeV. We obtain [tau] ([Lambda]0b ) = 1.303 ± 0.075 (stat.) ± 0.035 (syst.) ps, [tau] (B0) = 1.508±0.025 (stat.)±0.043 (syst.) ps and [tau] ([Lambda]0b )/[tau] (B0) = 0.864± 0.052 (stat.)±0.033 (syst.). These measurements supersede previous results of the DØ Collaboration using the same decay channels. Our measurement of the lifetime ratio is in excellent agreement with theoretical predictions and compatible with the current world-average, but differs with the latest measurement of the CDF Collaboration in more than 2 standard deviations.

Download or read book A MEASUREMENT OF THE LIFETIME AND MIXING FREQUENCY OF NEUTRAL B MESONS WITH SEMILEPTONIC DECAYS IN THE BABAR DETECTOR written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The neutral B meson, consisting of a b quark and an anti-d quark, can mix (oscillate) to its own anti-particle through second-order weak interactions. The measurement of the mixing frequency can constrain the quark mixing matrix in the Standard Model of particle physics. The PEP-II B-factory at the Stanford Linear Accelerator Center provides a very large data sample that enables us to make measurements with much higher precisions than previous measurements, and to probe physics beyond the Standard Model. The lifetime of the neutral B meson[tau][sub B0] and the B[sup 0]-[bar B][sup 0] mixing frequency[Delta]m[sub d] are measured with a sample of approximately 14,000 exclusively reconstructed B[sup 0][yields] D*[sup -][ell][sup+][nu][sub[ell]] signal events, selected from 23 million B[bar B] pairs recorded at the[Upsilon](4S)resonance with the BABAR detector at the asymmetric-energy e[sup+]e[sup -] collider, PEP-II. The decay position of the exclusively reconstructed B is determined by the charged tracks in the final state, and its b-quark flavor at the time of decay is known unambiguously from the charge of the lepton. The decay position of the other B is determined inclusively, and its b-quark flavor at the time of decay is determined (tagged) with the charge of tracks in the final state, where identified leptons or kaons give the most information. The decay time difference of two B mesons in the event is calculated from the distance between their decay vertices and the Lorentz boost of the center of mass. Additional samples of approximately 50,000 events are selected for studies of background events. The lifetime and mixing frequency, along with wrong-tag probabilities and the time-difference resolution function, are measured simultaneously with an unbinned maximum-likelihood fit that uses, for each event, the measured difference in B decay times ([Delta]t), the calculated uncertainty on[Delta]t, the signal and background probabilities, and b-quark tagging for the other B meson. The results are[tau][sub B[sup 0]]= (1.523[sub -0.023][sup+0.024][+-] 0.022) ps and[Delta]m[sub d]= (0.492[+-] 0.018[+-] 0.013) ps[sup -1], where the first error is statistical and the second is systematic. The statistical correlation coefficient between[tau][sub B[sup 0]] and[Delta]m[sub d] is -0.22. This result is consistent with the current world average values, the total errors are comparable with other most-precise measurements.