Absolute luminosity measurements with the LHCb detector at the LHC

Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. Using data taken in 2010, LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic "van der Meer scan" method a novel technique has been developed which makes use of direct imaging of the individual beams using beam-gas and beam-beam interactions. This beam imaging method is made possible by the high resolution of the LHCb vertex detector and the close proximity of the detector to the beams, and allows beam parameters such as positions, angles and widths to be determined. The results of the two methods have comparable precision and are in good agreement. Combining the two methods, an overall precision of 3.5% in the absolute luminosity determination is reached. The techniques used to transport the absolute luminosity calibration to the full 2010 data-taking period are presented.Comment: 48 pages, 19 figures. Results unchanged, improved clarity of Table 6, 9 and 10 and corresponding explanation in the tex

Absolute luminosity measurements with the LHCb detector at the LHC

Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. Using data taken in 2010, LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic "van der Meer scan" method a novel technique has been developed which makes use of direct imaging of the individual beams using beam-gas and beam-beam interactions. This beam imaging method is made possible by the high resolution of the LHCb vertex detector and the close proximity of the detector to the beams, and allows beam parameters such as positions, angles and widths to be determined. The results of the two methods have comparable precision and are in good agreement. Combining the two methods, an overall precision of 3.5% in the absolute luminosity determination is reached. The techniques used to transport the absolute luminosity calibration to the full 2010 data-taking period are presented.Comment: 48 pages, 19 figures. Results unchanged, improved clarity of Table 6, 9 and 10 and corresponding explanation in the tex

Absolute luminosity measurements with the LHCb detector at the LHC

Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. Using data taken in 2010, LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic "van der Meer scan" method a novel technique has been developed which makes use of direct imaging of the individual beams using beam-gas and beam-beam interactions. This beam imaging method is made possible by the high resolution of the LHCb vertex detector and the close proximity of the detector to the beams, and allows beam parameters such as positions, angles and widths to be determined. The results of the two methods have comparable precision and are in good agreement. Combining the two methods, an overall precision of 3.5% in the absolute luminosity determination is reached. The techniques used to transport the absolute luminosity calibration to the full 2010 data-taking period are presented.Comment: 48 pages, 19 figures. Results unchanged, improved clarity of Table 6, 9 and 10 and corresponding explanation in the tex

Caterpillars of Siderose marthesia nemesis (Illiger) (Lepidoptera, Nymphalidae, Charaxinae) in cerrado near Brasília, Distrito Federal, Brazil

Caterpillars of Siderone marthesia nemesis (Illiger, 1802) (Nymphalidae, Charaxinae) have been found on Casearia sylvestris Sw. (Flacourtiaceae), during the second half of the rainy season in an area of cerrado near Brasília, Distrito Federal, Brazil. They occurred at very low density and are cryptic at all instars. The pupal stage does not occur on the host plant. Average duration of the pupa under laboratory conditions is 14.4 days

Richness And Abundance Of Caterpillars On Byrsonima (malpighiaceae) Species In An Area Of Cerrado Vegetation In Central Brazil

We sampled lepidopteran caterpillars on three Byrsonima species (Malpighiaceae) in Central Brazil: Byrsonima crassa , Byrsonima verbascifolia and Byrsonima coccolobifolia between May 1993 and July 1994. Fifteen individuals of each plant species were censused weekly. Our main goal was to estimate the abundance and richness of lepidopteran larvae within each plant species. Only 13% of the 1 621 sampled plants had caterpillars on their leaves. This percentage was similar within each plant species. We found a pattern of low abundance and high richness of lepidopteran species associated with Byrsonima. There were 48 morphospecies and 46% of them occurred just once. There was a higher similarity between the fauna of B. crassa and B. verbascifolia than between these and B. coccolobifolia. Once it is known that hairy leaves can affect herbivore colonization and foraging strategy, we suggest that differences in the lepidopteran community associated with Byrsonima spp. are linked with different levels of pubescence on the leaf surface of each plant species. This tendency in Byrsonima is supported by the small number of caterpillars found on young leaves of B. crassa and B. verbascifolia, which are quite hairy.474691695Andrade, I., Diniz, I.R., Morais, H.C., A lagarta de Cerconota achatina: Biologia e ocorrência em plantas hospedeiras do gênero Byrsonima (Malpighiaceae) (1996) Rev. Bras. Zool., 12, pp. 735-741Cappuccino, N., Mutual use of leaf-shelters by lepidopteran larvae on paper birch (1993) Ecol. Entomol., 18, pp. 287-292De Vries, P.J., (1987) The Butterflies of Costa Rica, , Princenton University Press, New Jersey, 327 pDiniz, I.R., Morais, H.C., Lepidopteran caterpillar fauna of cerrado host plants (1997) Biodiv. Conserv., 6, pp. 817-836Fielding, C.A., Coulson, J.C., A test of the validity of insect food-plant and life history records: Lepidoptera on heather (Calluna vulgaris) (1995) Ecol. Entomol., 20, pp. 343-350Janzen, D.H., Ecological characterization of a Costa Rican Dry Forest caterpillar fauna (1988) Biotropica, 20, pp. 120-135Lawton, J.H., Vacant niches and unsaturated communities: A comparison of bracken herbivores at sites on two continents (1982) J. Anim. Ecol., 51, pp. 573-595Leather, S.R., Insect species richness of the British Rosaceae: The importance of host range, plant architecture, age of establishment, taxonomic isolation and species-area relationships (1986) J. Anim. Ecol., 55, pp. 841-860Lewinsohn, T.M., Insects in flower heads of Asteraceae in southeast Brazil: A case study on tropical species richness (1991) Plant-animal Interactions: Evolutionary Ecology in Tropical and Temperate Regions, pp. 525-560. , Price P. W, T. M. Lewinsohn, G. W. Fernandes & W. W. Benson (eds.). John Wiley & Sons, New YorkLoyola, R., Fernandes, G.W., Herbivoria em Kielmeyera coriacea (Guttiferae): Efeitos da idade da planta, desenvolvimento e aspectos qualitativos de folhas (1993) Rev. Bras. Biol., 53, pp. 295-304Marquis, R.J., Herbivore fauna of Piper (Piperaceae) in a Costa Rican Wet Forest: Diversity, specificity and impact (1991) Plant-animal Interactions: Evolutionary Ecology in Tropical and Temperate Regions, pp. 179-205. , P. W. Price, T. M. Lewinsohn, G. W. Fernandes & W. W. Benson (eds.). John Wiley & Sons, New YorkMarquis, R.J., Braker, H.E., Plant-herbivory interactions: Diversity, specificity and impact (1994) La Selva: Ecology and Natural History of a Neotropical Rain Forest, pp. 261-281. , L. M. McDade, K. S. Bawa, H. A. Hespenheide & G. S. Hartshorn (eds.). The University of Chicago Press, ChicagoMorais, H.C., Diniz, I.R., Baumgarten, L.C., Padrões de produção de folhas e sua utilização por larvas de Lepidoptera em um Cerrado de Brasília, DF (1995) Rev. Bras. Bot., 18, pp. 165-172Neuvonen, S., Niemelä, P., Species richness of macrolepidoptera on Finnish deciduous trees and shrubs (1981) Oecologia, 51, pp. 364-370Price, P.W., Diniz, I.R., Morais, H.C., Marques, E.S.A., The abundance of insect herbivore species in the tropics: The high local richness of rare species (1995) Biotropica, 27, pp. 468-478Ratter, Dargie, An analysis of the floristic composition of 26 cerrado areas in Brazil (1992) Edinburgh J. Bot., 49, pp. 235-250Schluter, D., Ricklefs, R.E., Species diversity: An introduction to the problem (1993) Species Diversity in Ecological Communities: Historical and Geographical Perspectives, pp. 1-10. , R. E. Ricklefs, & D. Schluter (eds.). The University of Chicago Press, ChicagoSowthwood, T.R.E., Moran, V.C., Kennedy, C.E.J., The assessment of arboreal insect fauna: Comparisons of knockdown sampling and faunal lists (1982) Ecol. Entomol., 7, pp. 331-340Southwood, T.R.E., Plant surfaces and insects - An overview (1986) Insects and the Plant Surface, pp. 1-22. , B. Juniper& R. Sowthwood (eds.). Edward Arnold, Baltimor