Download or read book Measurement of the Lambda b 0 Lifetime Using Semileptonic Decays written by and published by . This book was released on 2007 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Measurement of the Lambda b Baryon Lifetime in Z Decays written by Owen J. Hayes and published by . This book was released on 1999 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Measurement of the measurement of Lambda Sub B BO Bar Sub d B Minus B Bar Sub s Lifetimes written by Frederick V. Weber and published by . This book was released on 1993 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Neutral B Meson Time Evolution Using Exclusively Reconstructed Semileptonic Decays written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Standard Model of particle physics describes the fundamental building blocks of the Universe and their basic interactions. The model naturally describes the time evolution of the basic particles, of which lifetime and mixing are two examples. The neutral B meson, consisting of a bottom quark and an oppositely charged down quark, enjoys a lifetime of about 1.5 ps and the special property of mixing with its antiparticle partner, the [bar B][sup 0]. That is, due to second order weak interactions, the B[sup 0] meson can change into a [bar B][sup 0] meson and back again as it evolves through time. The details of this behavior offer an opportunity to closely examine the Standard Model. In this dissertation, I report on a measurement of the lifetime and mixing frequency of the neutral B meson. Using the semileptonic decay channel B[sup 0] [yields] D*[sup -][ell][sup +][bar [nu]][sub [ell]], we select more than 68,000 signal and background candidates from about 23 million B[bar B] pairs collected in 1999-2000 with the BABAR detector located at the Stanford Linear Accelerator Center. The other B in the event is reconstructed inclusively. By constructing a master probability density function that describes the distribution of decay time differences in the sample, we use a maximum likelihood technique to simultaneously extract the B[sup 0] lifetime and mixing parameters with precision comparable to the year 2000 world average. 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]. The statistical correlation coefficient between [tau][sub B[sup 0]] and [Delta]m[sub d] is -0.22. I describe in detail several cutting-edge strategies this analysis uses to study these phenomena, laying important groundwork for the future. I also discuss several extensions of this work to include possible measurements of higher order parameters such as [Delta][Lambda][sub d].
Download or read book Measurement of the B and bar B Meson Lifetimes Using Semileptonic Decays written by and published by . This book was released on 1995 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The lifetimes of the B− and {bar B}° mesons are measured using the partially reconstructed semileptonic decays in the CDF experiment.
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 Search for Semileptonic Decays in the B Meson Into the Lambda subscript C Baryon written by Tomohiko Tanabe and published by . This book was released on 2009 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Lambda b Lifetime in the Exclusive Decay Lambda b J written by and published by . This book was released on 2007 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have measured the?{sub b} lifetime using the exclusive decay?{sub b}→J/??, based on 1.2 fb−1 of data collected with the D0 detector during 2002-2006. From 171 reconstructed?{sub b} decays, where the J/? and? are identified via the decays J/??????????− and????????p?, we measured the?{sub b} lifetime to be?(?{sub b})=1.218{sub -0.115}{sup +0.130}(stat)±0.042(syst) ps. We also measured the B° lifetime in the decay B°→J/?(?+?−)K{sub S}°(?+?−) to be?(B°)=1.501{sub -0.074}{sup +0.078}(stat)±0.050(syst) ps, yielding a lifetime ratio of?(?{sub b})/?(B°)=0.811{sub -0.087}{sup +0.096}(stat)±0.034(syst =).
Download or read book Measurement of the Lambda subscript B Lifetime in the Decay Mode Lambda subscript B right Arrow J psi Lambda written by Robyn Madrak and published by . This book was released on 2003 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the B s0 Lifetime in B s0 K K Decays written by and published by . This book was released on 2009 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method is presented to simultaneously separate the contributions to a sample of B{sub (s)}° 2!hh{sup {prime}-} decays, where h = [pi] or K, and measure the B meson lifetimes in the sample while correcting for the bias in the lifetime distributions due to the hadronic trigger at the CDF experiment. Using 1 fb−1 of data collected at CDF the B° lifetime is measured as [tau]{sub B°} = 1.558{sub -0.047}{sup +0.050}{sub stat} ± 0.028{sub syst} ps, in agreement with the world average measurement. The B{sub s}° lifetime in the B{sub s}° 2!KK− decay is measured as [tau]{sub B{sub s}° 2!K+K−} = 1.51{sub -0.11}{sup +0.13}{sub stat} ± 0.04{sub syst} ps. No difference is observed between the lifetime and other measurements of the average B{sub s}° lifetime or the lifetime of the light B{sub s}° mass eigenstate determined from B{sub s}° 2!J/[psi][phi] decays. With the assumptions that B{sub s}° 2!K+K− is 100% CP-even and that [tau]{sub B{sub s}°} = [tau]{sub B°} the width difference in the B{sub s}{sup 0} system is determined as [Delta][Lambda]{sup CP}/[Lambda] = 0.03{sub -0.15}{sup +0.17}{sub stat} ± 0.05{sub syst} using the current world average B{sup 0} lifetime. This is consistent with zero and with the current world average measurement.
Download or read book Measurement of the B0 Lifetime with Partially Reconstructed B0 D L u Decays written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The B[sup 0] lifetime has been measured with a sample of 23 million B[bar B] pairs collected by the BABAR detector at the PEP-II e[sup+]e[sup -] storage ring during 1999 and 2000. Events from the semileptonic decay B[sup 0][yields] D*[sup -][ell][sup+][nu][sub[ell]] have been selected with a partial reconstruction method in which only the charged lepton and the slow[pi] from the D*[sup -][yields][bar D][sup 0][pi][sup -] decay are reconstructed. The result is[tau][sub B][sup 0]= 1.529[+-] 0.012 (stat)[+-] 0.029 (syst) ps.
Download or read book A Precise Measurement of the B0 s Lifetime 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 B{sub s}° lifetime in the semileptonic decay channel B{sub s}° → D{sub s}−??X (and its charge conjugate), using approximately 0.4 fb−1 of data collected with the D0 detector during 2002-2004. They have reconstructed 5176 D{sub s}−?+ signal events, where the D{sub s}− is identified via the decay D{sub s}° →??−, followed by? → K+K−. Using these events, they have measured the B{sub s}° lifetime to be?(B{sub s}°) = 1.398 ± 0.044 (stat){sub -0.025}{sup +0.028}(syst) ps. This is the most precise measurement of the B{sub s}° lifetime to date.
Download or read book Measurement of the B and Bar Bsup O Meson Lifetimes Using Semileptonic Decays written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Neutral B Meson Time Evolution Using Exclusively Reconstructed Semileptonic Decays written by T. Meyer and published by . This book was released on 2003 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Standard Model of particle physics describes the fundamental building blocks of the Universe and their basic interactions. The model naturally describes the time evolution of the basic particles, of which lifetime and mixing are two examples. The neutral B meson, consisting of a bottom quark and an oppositely charged down quark, enjoys a lifetime of about 1.5 ps and the special property of mixing with its antiparticle partner, the {bar B}{sup 0}. That is, due to second order weak interactions, the B{sup 0} meson can change into a {bar B}{sup 0} meson and back again as it evolves through time. The details of this behavior offer an opportunity to closely examine the Standard Model. In this dissertation, I report on a measurement of the lifetime and mixing frequency of the neutral B meson. Using the semileptonic decay channel B{sup 0} {yields} D*{sup -}{ell}{sup +}{bar {nu}}{sub {ell}}, we select more than 68,000 signal and background candidates from about 23 million B{bar B} pairs collected in 1999-2000 with the BABAR detector located at the Stanford Linear Accelerator Center. The other B in the event is reconstructed inclusively. By constructing a master probability density function that describes the distribution of decay time differences in the sample, we use a maximum likelihood technique to simultaneously extract the B{sup 0} lifetime and mixing parameters with precision comparable to the year 2000 world average. 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}. The statistical correlation coefficient between {tau}{sub B{sup 0}} and {Delta}m{sub d} is -0.22. I describe in detail several cutting-edge strategies this analysis uses to study these phenomena, laying important groundwork for the future. I also discuss several extensions of this work to include possible measurements of higher order parameters such as {Delta}{Lambda}{sub d}.
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 Physics is Fun Memoirs of a Life in Physics written by Richard Wilson and published by Richard Wilson. This book was released on 2011 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt:
