61,015 research outputs found
Measurement of the ratio of branching fractions B(B0→K∗0γ )/B(B0s→φγ ) and the directCP asymmetry inB 0→K∗0γ
Get PDFThe ratio of branching fractions of the radiative B decays B0→K⁎0γ and B0s→ϕγ has been measured using an integrated luminosity of 1.0 fb−1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of s√=7TeV. The value obtained is
B(B0→K⁎0γ)B(B0s→ϕγ)=1.23±0.06(stat.)±0.04(syst.)±0.10(fs/fd),
where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for B(B0→K⁎0γ), the branching fraction B(B0s→ϕγ) is measured to be (3.5±0.4)×10−5.
The direct CP asymmetry in B0→K⁎0γ decays has also been measured with the same data and found to be
ACP(B0→K⁎0γ)=(0.8±1.7(stat.)±0.9(syst.))%.
Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations
Chan An Ancient Maya Farming Community
No full textThe farming community of Chan thrived for over twenty centuries, surpassing the longevity of many larger Maya urban centers. Between 800 BC and 1200 AD it was a major food production center, and this collection of essays reveals the important role played by Maya farmers in the development of ancient Maya society. Chan offers a synthesis of compelling and groundbreaking discoveries gathered over ten years of research at this one archaeological site in Belize. The contributors develop three central themes, which structure the book. They examine how sustainable farming practices maintained the surrounding forest, allowing the community to exist for two millennia. They trace the origins of elite Maya state religion to the complex religious belief system developed in small communities such as Chan. Finally, they describe how the group-focused political strategies employed by local leaders differed from the highly hierarchical strategies of the Classic Maya kings in their large cities. In breadth, methodology, and findings, this volume scales new heights in the study of Maya society and culture.Cover -- Title -- Copyright -- Contents -- List of Figures -- List of Tables -- Foreword -- Acknowledgments -- 1. Introducing the Chan Site: Farmers in Complex Societies -- Part 1. Time, Space, and Landscapes -- 2. A Changing Cultural Landscape: Settlement Survey and GIS at Chan -- 3. Ceramics and Chronology at Chan -- 4. Agricultural Practices at Chan: Farming and Political Economy in an Ancient Maya Community -- 5. Agroforestry and Agricultural Production of the Ancient Maya at Chan -- Part 2. Life in a Farming Community Center -- 6. Ritual in a Farming Community -- 7. Nonroyal Governance at Chan's Community Center -- 8. "Empty" Spaces and Public Places: A Microscopic View of Chan's Late Classic West Plaza -- Part 3. Diversity across the Chan Community -- 9. Recognizing Difference in Small-Scale Settings: An Examination of Social Identity Formation at the Northeast Group, Chan -- 10. Organization of Chert Tool Economy during the Late and Terminal Classic Periods at Chan: Preliminary Thoughts Based upon Debitage Analyses -- 11. Limestone Quarrying and Household Organization at Chan -- Part 4. Bodies, Material Culture, and Meaning -- 12. The Chan Community: A Bioarchaeological Perspective -- 13. Creating Community with Shell -- 14. Obsidian Acquisition, Trade, and Regional Interaction at Chan -- 15. Contextualizing Ritual Behavior: Caches, Burials, and Problematical Deposits from Chan's Community Center -- Part 5. Conclusion -- 16. Learning from an Ancient Maya Farming Community -- References -- List of Contributors -- Index -- A -- B -- C -- D -- E -- F -- G -- H -- I -- J -- K -- L -- M -- N -- O -- P -- Q -- R -- S -- T -- V -- W -- X -- YThe farming community of Chan thrived for over twenty centuries, surpassing the longevity of many larger Maya urban centers. Between 800 BC and 1200 AD it was a major food production center, and this collection of essays reveals the important role played by Maya farmers in the development of ancient Maya society. Chan offers a synthesis of compelling and groundbreaking discoveries gathered over ten years of research at this one archaeological site in Belize. The contributors develop three central themes, which structure the book. They examine how sustainable farming practices maintained the surrounding forest, allowing the community to exist for two millennia. They trace the origins of elite Maya state religion to the complex religious belief system developed in small communities such as Chan. Finally, they describe how the group-focused political strategies employed by local leaders differed from the highly hierarchical strategies of the Classic Maya kings in their large cities. In breadth, methodology, and findings, this volume scales new heights in the study of Maya society and culture.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
Branching fraction and CP asymmetry of the decays B+→K0Sπ+ and B+→K0SK+
Get PDFAn analysis of B+ → K0
Sπ+ and B+ → K0
S K+ decays is performed with the LHCb experiment. The pp
collision data used correspond to integrated luminosities of 1 fb−1 and 2 fb−1 collected at centre-ofmass
energies of
√
s = 7 TeV and
√
s = 8 TeV, respectively. The ratio of branching fractions and the
direct CP asymmetries are measured to be B(B+ → K0
S K+
)/B(B+ → K0
Sπ+
) = 0.064 ± 0.009 (stat.) ±
0.004 (syst.), ACP(B+ → K0
Sπ+
) = −0.022 ± 0.025 (stat.) ± 0.010 (syst.) and ACP(B+ → K0
S K+
) =
−0.21 ± 0.14 (stat.) ± 0.01 (syst.). The data sample taken at
√
s = 7 TeV is used to search for
B+
c
→ K0
S K+ decays and results in the upper limit ( fc · B(B+
c
→ K0
S K+
))/( fu · B(B+ → K0
Sπ+
)) <
5.8 × 10−2 at 90% confidence level, where fc and fu denote the hadronisation fractions of a ¯b
quark
into a B+
c or a B+ meson, respectively
Measurement of branching fractions for B → χc1(2)K (K*) at Belle
No full textWe have measured the branching fractions for the exclusive decay modes B→χc1(2)K(K*) using a 140 fb-1 data sample collected by the Belle detector at the KEKB asymmetric-energy e +e- collider. The measured branching fractions for B +→χc1K+, B0→χ c1K0, B0→χc1K* 0 and B+→χc1K*+ decay modes are (4.5±0.2±0.5)×10-4, (3.5±0.3±0.5)×10-4, (3.1±0.3±0.7) ×10-4 and (4.1±0.6±0.9)×10-4, respectively, where the first error is statistical and the second error is systematic. We do not observe statistically significant signals for the B→χc2K(K*) decay modes and set upper limits at the 90% confidence level. We also study the helicity distribution for B→χc1K* decay mode and show that the longitudinal polarization component is dominant. © 2006 Elsevier B.V. All rights reserved.LPH
Search for the suppressed decays B+→K+K+π− and B+→π+π+K−
No full text© 2016 The Author A search is made for the highly-suppressed B meson decays B+→K+K+π− and B+→π+π+K− using a data sample corresponding to an integrated luminosity of 3.0 fb−1 collected by the LHCb experiment in proton–proton collisions at centre-of-mass energies of 7 and 8 TeV. No evidence is found for the decays, and upper limits at 90% confidence level are determined to be B(B+→K+K+π−)<1.1×10−8 and B(B+→π+π+K−)<4.6×10−8
First observation of the decay Bs0→K*0K*0
Get PDFThe first observation of the decay B0s→K∗0K∗0 is reported using 35 pb−1 of data collected by LHCb in proton–proton collisions at a centre-of-mass energy of 7 TeV. A total of 49.8±7.5 B0s→(K+π−)(K−π+) events are observed within ±50 MeV/c2 of the B0s mass and 746 MeV/c2 < mKπ < 1046 MeV/c2, mostly coming from a resonant B0s→K∗0K∗0 signal. The branching fraction and the CP-averaged K∗0 longitudinal polarization fraction are measured to be B(B0s→K∗0K∗0)=(2.81±0.46(stat.)±0.45(syst.)±0.34(fs/ fd))×10−5 and fL =0.31±0.12(stat.)±0.04(syst.)
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Measurement of the CKM angle gamma from a combination of B->Dh analyses
Get PDFA combination of three LHCb measurements of the CKM angle gamma is presented. The decays B->DK and B->Dpi are used, where D denotes an admixture of D0 and D0-bar mesons, decaying into K+K-, pi+pi-, K+-pi-+, K+-pi-+pi+-pi-+, KSpi+pi-, or KSK+K- final states. All measurements use a dataset corresponding to 1.0 fb-1 of integrated luminosity. Combining results from B->DK decays alone a best-fit value of gamma = 72.0 deg is found, and confidence intervals are set gamma in [56.4,86.7] deg at 68% CL, gamma in [42.6,99.6] deg at 95% CL. The best-fit value of gamma found from a combination of results from B->Dpi decays alone, is gamma = 18.9 deg, and the confidence intervals gamma in [7.4,99.2] deg or [167.9,176.4] deg at 68% CL, are set, without constraint at 95% CL. The combination of results from B->DK and B->Dpi decays gives a best-fit value of gamma = 72.6 deg and the confidence intervals gamma in [55.4,82.3] deg at 68% CL, gamma in [40.2,92.7] deg at 95% CL are set. All values are expressed modulo 180 deg, and are obtained taking into account the effect of D0-D0bar mixing
Observation of the suppressed ADS modes B± → [π±K-/+ π+π-]D K± and B± → [π± K-/+π+π-]Dπ±
Get PDFAn analysis of and B± → DK± and B± → Dπ±
decays is presented where the D meson is reconstructed in the four-body final state K± π-/+π+π-. Using LHCb data corresponding to an integrated luminosity of 1.0 fb-1, first observations are made of the suppressed ADS modes B± →[π± K-/+π+π-]DK± and B± → [π± K-/+π+π-]Dπ± with a significance of 5.1 sigma and greater than 10 sigma, respectively. Measurements of CP asymmetries and CP-conserving ratios of partial widths from this family of decays are also performed. The magnitude of the ratio between the suppressed and favoured B± → DK ± amplitudes is determined to be rKB = 0.097 ± 0.011
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