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 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 Measurement of the Lambda 0 b Lambda c Pi Branching Ratio written by Yi Le and published by . This book was released on 2003 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present a measurement of the {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +} {pi}{sup -} branching ratio in p{bar p} collisions at {radical}s = 1.96 TeV using 65 pb{sup -1} data collected by the Collider Detector at Fermilab (CDF). The measurement starts from reconstructing two decay modes: {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}, where {Lambda}{sub c}{sup +} {yields} p K{sup -} {pi}{sup +}; and {bar B}{sup 0} {yields} D{sup +}{pi}{sup -}, where D{sup +} {yields} {pi}{sup +} K{sup -} {pi}{sup +}. The authors obtained 96 {+-} 13 {Lambda}{sub b}{sup 0} and 321 {+-} 22 {bar B}{sup 0} candidates from the CDF Run II Two-Track Hadronic Trigger data sample. The relative branching ratio of the two decays is then measured based on the equation: f{sub {Lambda}{sub b}} BR({Lambda}{sub b} {yields} {Lambda}{sub c}{sup +} {pi}{sup -})/f{sub d} BR({bar B}{sup 0} {yields} D{sup +} {pi}{sup -}) = BR(D{sup +} {yields} K{pi}{pi}) N{sub {Lambda}{sub b}} {epsilon}{sub B{sup 0}}/BR({Lambda}{sub c}{sup +} {yields} pK{pi}) N{sub {bar B}{sup 0}} {epsilon}{sub {Lambda}{sub b}}. The measurement gives f{sub {Lambda}{sub b}} BR({Lambda}{sub b} {yields} {Lambda}{sub c}{sup +}{pi}{sup -})/f{sub d} BR({bar B}{sup 0} {yields} D{sup +}{pi}{sup -}) = 0.66 {+-} 0.11(stat) {+-} 0.09(syst) {+-} 0.18(BR). The {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -} branching ratio is then extracted, giving BR({Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -}) = (6.6 {+-} 1.2(stat.) {+-} 0.9(syst.) {+-} 2.3(BR+FR)) x 10{sup -3}. The {Lambda}{sub b}{sup 0} sample they reconstructed in this analysis is the largest fully reconstructed {Lambda}{sub b}{sup 0} sample in existence. The result they report here on the {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -} branching ratio is the world's first such measurement.

Download or read book Radiation and Detectors written by Lucio Cerrito and published by Springer. This book was released on 2017-05-11 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook provides an introduction to radiation, the principles of interaction between radiation and matter, and the exploitation of those principles in the design of modern radiation detectors. Both radiation and detectors are given equal attention and their interplay is carefully laid out with few assumptions made about the prior knowledge of the student. Part I is dedicated to radiation, broadly interpreted in terms of energy and type, starting with an overview of particles and forces, an extended review of common natural and man-made sources of radiation, and an introduction to particle accelerators. Particular attention is paid to real life examples, which place the types of radiation and their energy in context. Dosimetry is presented from a modern, user-led point of view, and relativistic kinematics is introduced to give the basic knowledge needed to handle the more formal aspects of radiation dynamics and interaction. The explanation of the physics principles of interaction between radiation and matter is given significant space to allow a deeper understanding of the various technologies based on those principles. Following an introduction to the ionisation mechanism, detectors are introduced in Part II, grouped according to the physical principle that underpins their functionality, with chapters covering gaseous detectors, semiconductor detectors, the scintillation process and light detectors. The final two chapters describe the phenomenology of showers and the design of calorimeters, and cover additional phenomena including Cherenkov and transition radiation and the detection of neutrinos. An appendix offers the reader a useful review of statistics and probability distributions. The mathematical formalism is kept to a minimum throughout and simple derivations are presented to guide the reasoning and facilitate understanding of the working principles. The book is unique in its wide scope and introductory level, and is suitable for undergraduate and graduate students in physics and engineering. The reader will acquire an awareness of how radiation and its exploitation are becoming increasingly relevant in the modern world, with over 140 experimental figures, detector schematics and photographs helping to relate the material to a broader research context.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1989 with total page 780 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Energy Physics Index written by and published by . This book was released on 1992 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1989 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes all works deriving from DOE, other related government-sponsored information and foreign nonnuclear information.

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.

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 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 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 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 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 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 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 Lambda b Lifetime in Lambda b Lambda c Pi Decays in P pbar Collisions at Sqrt s written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report a measurement of the lifetime of the?{sub b}° baryon in decays to the?{sub c}?− final state in a sample corresponding to 1.1 fb−1 collected in p{bar p} collisions at √s = 1.96 TeV by the CDF II detector at the Tevatron collider. Using a sample of about 3000 fully reconstructed?{sub b}° events we measure?(?{sub b}°) = 1.401 ± 0.046 (stat) ± 0.035 (syst) ps (corresponding to c?(?{sub b}°) = 420.1 ± 13.7 (stat) ± 10.6 (syst)?m, where c is the speed of light). The ratio of this result and the world average B° lifetime yields?(?{sub b}°)/?(B°) = 0.918 ± 0.038 (stat and syst), in good agreement with recent theoretical predictions.

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1989 with total page 1178 pages. Available in PDF, EPUB and Kindle. Book excerpt: