Download or read book Measurement of Neutral B Meson and Charged B Meson Lifetimes Using Semileptonic Decays at CDF written by David K. Clark and published by . This book was released on 2010 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 B Lifetimes at CDF written by and published by . This book was released on 1995 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two measurements of the lifetime of neutral and charged B mesons in p{bar p} collisions at √s = 1.8 TeV by the CDF experiment are presented. The first relies on the study of exclusive decays of the type B → [psi] K, the second on semileptonic decays of a B meson into a D° or a D. The combined results are [tau](B+) = 1.62 ± 0.09 ps, [tau](B0) = 1.60 ± 0.09 ps and [tau](B+)/[tau](B°) = 1.00 ± 0.07.
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.
Download or read book Measurement of the B sup and B sup 0 Lifetimes at CDF written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Two measurements of the lifetime of neutral and charged B mesons in p[bar p] collisions at[radical]s= 1.8 TeV by the CDF experiment are presented. The first relies on the study of exclusive decays of the type B[yields][psi] K, the second on semileptonic decays of a B meson into a D[degrees] or a D. The combined results are[tau](B[sup+])= 1.62[+-] 0.09 ps, [tau](B[sub 0])= 1.60[+-] 0.09 ps and[tau](B[sup+])/[tau](B[sup 0])= 1.00[+-] 0.07.
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 the B and B Lifetimes from Semileptonic Decays at SLD 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 lifetimes of B and B° mesons have been measured using a sample of 150,000 hadronic Z° decays collected by the SLD experiment at the SLC between 1993 and 1995. The analysis identifies the semileptonic decays of B mesons with high (p, p{sub t}) leptons and reconstructs the B meson decay length and charge by vertexing the lepton with a partially reconstructed D meson. This method results in a sample of 634 (584) charged (neutral) decays with high charge purity. A maximum likelihood fit finds: [tau]{sub B{sup +}} = 1.60{sub -0.11}{sup +0.12}(stat) ± 0.06(syst) ps, [tau]{sub B{sup 0}} = 1.55{sub -0.12}{sup +0.13}(stat) ± 0.09(syst) ps, and the ratio [tau]{sub B{sup +}}/[tau]{sub B{sup 0}} = 1.03{sub -0.13}{sup +0.15}(stat) ± 0.08(syst).
Download or read book A Measurement of the Charged and Neutral B Meson Lifetimes Using Fully Reconstructed Decays written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Data collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC are used to study the lifetimes of the B° and B mesons. The data sample consists of 7.4 fb−1 collected near the Upsilon(4S) resonance. B° and B mesons are fully reconstructed in several exclusive hadronic decay modes to charm and charmonium final states. The B lifetimes are determined from the flight length difference between the two B mesons which are pair-produced in the Upsilon(4S) decay. The preliminary measurements of the lifetimes are tau{sub B0} = 1.506 " 0.052 (stat) " 0.029 (syst) ps, tau{sub B+} = 1.602 " 0.049 (stat) " 0.035 (syst) ps, and of their ratio is tau{sub B+}/tau{sub B0} = 1.065 " 0.044 (stat) " 0.021 (syst).
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 A Measurement of the Charged and Neutral B Meson Lifetimes Using Fully Reconsructed Decay Modes written by Alan Richard Spies and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the B sup and B sup 0 Lifetimes from Semileptonic Decays at SLD written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The lifetimes of B[sup+] and B[sup 0] mesons have been measured using a sample of 150,000 hadronic Z[sup 0] decays collected by the SLD experiment at the SLC between 1993 and 1995. The analysis identifies the semileptonic decays of B mesons with high (p, p[sub t]) leptons and reconstructs the B meson decay length and charge by vertexing the lepton with a partially reconstructed D meson. This method results in a sample of 634 (584) charged (neutral) decays with high charge purity. A maximum likelihood fit finds:[tau][sub B[sup+]]= 1.60[sub[minus]0.11][sup+0.12](stat)[+-] 0.06(syst) ps, [tau][sub B[sup 0]]= 1.55[sub[minus]0.12][sup+0.13](stat)[+-] 0.09(syst) ps, and the ratio[tau][sub B[sup+]]/[tau][sub B[sup 0]]= 1.03[sub[minus]0.13][sup+0.15](stat)[+-] 0.08(syst).
Download or read book Eps High Energy Physics 95 Proceedings Of The International Europhysics Conference written by Catherine Vander Velde and published by World Scientific. This book was released on 1996-05-28 with total page 1042 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preliminary Measurement of Time dependent B sub D sup 0 B sub D sup 0 Mixing Using Topology and Charge Selected Semi leptonic B Decays written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The time dependence of B[sub d][sup 0]-B[sub d][sup 0] mixing has been measured using a sample of 150,000 hadronic Z[sup 0] decays collected by the SLD experiment at the SLC between 1993 and 1995. The analysis identifies the semileptonic decays of B mesons with high (p, p[sub t]) leptons and reconstructs the B meson decay length and charge by vertexing the lepton with a partially reconstructed D meson. Vertex charge is used to enrich the selection of neutral over charged B mesons. This method results in a sample of 581 neutral decays with high charge purity. The B candidate is tagged at production with a combined tag that exploits the large polarized b forward-backward asymmetry in conjunction with the opposite hemisphere b jet charge. The final state is tagged by the sign of the high (p, p[sub t]) lepton. From their preliminary analysis the authors find a mass difference between the two B[sub d][sup 0] mass eigenstates of, [Delta]m[sub d]= 0.452[+-] 0.074(stat)[+-] 0.049(syst) ps[sup[minus]1].
Download or read book Semileptonic Decay of the Neutral B Meson Into a D Meson written by Cristiano Borean and published by . This book was released on 2003 with total page 244 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 Semileptonic B Meson to D star Meson Decay written by Mauricio Garcia-Sciveres and published by . This book was released on 1994 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
