7,374 research outputs found
B Mixing and Lifetime Measurements with the BaBar Detector
Recent BaBar measurements on lifetime and mixing of B mesons are reported.
Various techniques are used, ranging from the full reconstruction of hadronic B
decays, to partial reconstruction techniques, and to a totally inclusive
approach with dilepton events. The results presented are based on a data sample
collected by BaBar during the 1999-2000 data taking, and should be considered
as preliminary.Comment: 6 pages, 5 postscript figues, submitted to BCP4 proceeding
Next-to-leading order QCD corrections to W+Z and W-Z production via vector-boson fusion
We present the calculation of the next-to-leading order QCD corrections to
electroweak p p -> e+ nu_e mu+ mu- jj and p p -> e- nubar_e mu+ mu- jj
production at the CERN LHC in the form of a fully flexible parton-level Monte
Carlo program. The QCD corrections to the total cross sections are modest,
changing the leading-order results by less than 10%. At the Born level, the
shape of kinematic distributions can depend significantly on the choice of
factorization scale. This theoretical uncertainty is strongly reduced by the
inclusion of the next-to-leading order QCD corrections.Comment: 15 pages, 6 figures; new figure and comments added; version published
by PR
Transverse-Momentum Resummation for Slepton-Pair Production at the LHC
We perform a first precision calculation of the transverse-momentum (q_T)
distribution of slepton pair and slepton-sneutrino associated production at the
CERN Large Hadron Collider (LHC). We implement soft-gluon resummation at the
next-to-leading logarithmic (NLL) level and consistently match the obtained
result to the pure fixed-order perturbative result at leading order (LO) in the
QCD coupling constant, i.e. O(alpha_s). We give numerical predictions for
stau_1 stau_1^* and stau_1 sneutrino_tau^* + stau_1^* sneutrino_tau production,
also implementing recent parameterizations of non-perturbative effects. The
results show a relevant contribution of resummation both in the small and
intermediate q_T-regions and little dependence on unphysical scales and
non-perturbative contributions.Comment: 4 pages, 2 figure
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BaBar simulation production - A millennium of work in under a year
The BaBar experiment requires simulated events beyond the ability of a single computing site to provide. This paper describes the evolution of simulation and job management methods to meet the physics community requirements and how production became distributed to use resources beyond any one computing center. The evolution of BaBar simulation along with the development of the distribution of the computing effort is described. As the computing effort is distributed to more sites there is a need to simplify production so the effort does not multiply with number of production centers. Tools are created to be flexible in handling errors and failures that happen in the system and respond accordingly, this reduces failure rates and production effort. This paper will focus on one cycle of simulation production within BaBar as a description of a large scale computing effort which was fully performed, and provided new simulation data to the users on time
Non-Diagonal and Mixed Squark Production at Hadron Colliders
We calculate squared helicity amplitudes for non-diagonal and mixed squark
pair production at hadron colliders, taking into account not only loop-induced
QCD diagrams, but also previously unconsidered electroweak channels, which turn
out to be dominant. Mixing effects are included for both top and bottom
squarks. Numerical results are presented for several SUSY benchmark scenarios
at both the CERN LHC and the Fermilab Tevatron, including the possibilities of
light stops or sbottoms. The latter should be easily observed at the Tevatron
in associated production of stops and sbottoms for a large range of stop masses
and almost independently of the stop mixing angle. Asymmetry measurements for
light stops at the polarized BNL RHIC collider are also briefly discussed.Comment: 22 pages, 11 figure
UAV surveying for a complete mapping and documentation of archaeological findings. The early Neolithic site of Portonovo
The huge potential of 3D digital acquisition techniques for the documentation of archaeological sites, as well as the related findings, is almost well established. In spite of the variety of available techniques, a sole documentation pipeline cannot be defined a priori because of the diversity of archaeological settings. Stratigraphic archaeological excavations, for example, require a systematic, quick and low cost 3D single-surface documentation because the nature of stratigraphic archaeology compels providing documentary evidence of any excavation phase. Only within a destructive process each single excavation cannot be identified, documented and interpreted and this implies the necessity of a re- examination of the work on field. In this context, this paper describes the methodology, carried out during the last years, to 3D document the Early Neolithic site of Portonovo (Ancona, Italy) and, in particular, its latest step consisting in a
photogrammetric aerial survey by means of UAV platform. It completes the previous research delivered in the same site by means of terrestrial laser scanning and close range techniques and sets out different options for further reflection in terms of site coverage, resolution and campaign cost. With the support of a topographic network and a unique reference system, the full documentation of the site is managed in order to detail each excavation phase; besides, the final output proves how the 3D digital methodology can be completely integrated with reasonable costs during the excavation and used to interpret the archaeological context. Further contribution of this work is the comparison between several acquisition techniques (i.e. terrestrial and aerial), which could be useful as decision support system for different archaeological scenarios. The main objectives of the comparison are: i) the evaluation of 3D mapping
accuracy from different data sources, ii) the definition of a standard pipeline for different archaeological needs and iii) the provision of different level of detail according to the user need
Estimation of linkage disequilibrium and effective population size in three Italian autochthonous beef breeds
The objective was to investigate the pattern of linkage disequilibrium (LD) in three local beef breeds, namely, Calvana (n = 174), Mucca Pisana (n = 270), and Pontremolese (n = 44). As a control group, samples of the Italian Limousin breed (n = 100) were used. All cattle were genotyped with the GeneSeek GGP-LDv4 33k SNP chip containing 30,111 SNPs. The genotype quality control for each breed was conducted separately, and SNPs with call rate < 0.95 and minor allele frequency (MAF) > 1% were used for the analysis. LD extent was estimated in PLINK v1.9 using the squared correlation between pairs of loci (r2) across autosomes. Moreover, r2 values were used to calculate historical and contemporary effective population size (Ne) in each breed. Average r2 was similar in Calvana and Mucca Pisana (~0.14) and higher in Pontremolese (0.17); Limousin presented the lowest LD extent (0.07). LD up to 0.11–0.15 was persistent in the local breeds up to 0.75 Mbp, while in Limousin, it showed a more rapid decay. Variation of different LD levels across autosomes was observed in all the breeds. The results demonstrated a rapid decrease in Ne across generations for local breeds, and the contemporary population size observed in the local breeds, ranging from 41.7 in Calvana to 17 in Pontremolese, underlined the demographic alarming situation
Constitutional Law - Federal Investigatory Power over Bi-State Agency through Reservation to Congress under Compact Clause of Constitution
Anti-doping policy and professional cycling : exploring attitudes, issues and a pathway to a new approach
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