Clinical and microbiological effects of copaiba oil (Copaifera officinalis) on dental plaque forming bacteria in dogs

O potencial de uso do óleo de copaíba (Copaifera officinalis) na prevenção da doença periodontal, eliminando seu agente etiológico, foi avaliado em 18 cães sem raça definida, distribuídos homogeneamente em três grupos: teste, (contendo óleo de copaíba) controle positivo e controle negativo. Os tratamentos ocorreram três vezes ao dia, durante oito dias. Ao nono dia, os animais receberam aplicação tópica de fucsina básica 0,5% para evidenciação do biofilme. Mudanças na halitose e gengivite foram avaliadas diariamente por inspeção visual. Adicionalmente, foram realizados testes laboratoriais de inibição de aderência de Streptococcus mutans e ensaio antimicrobiano de difusão em ágar, sobre bactérias formadoras de placa dental. Os resultados da placa evidenciada apontaram áreas de cobertura microbiana nos dentes de 53,4±8,8%, 28,5±5,4%, e 22,3±5,3% para os grupos negativo, positivo e teste, respectivamente, indicando diferença entre o controle negativo e os demais grupos (P<0,05). Quanto à melhora nos aspectos clínicos, halitose e gengivite, o grupo teste respondeu melhor quando comparado ao grupo controle negativo (P<0,05). A análise dos ensaios de difusão e inibição de aderência mostrou superioridade do grupo da copaíba (teste) em relação aos outros grupos (P<0,05). Os resultados sugerem o uso do óleo de copaíba na prevenção da doença periodontal e como um possível substituto da clorexidina na terapia antimicrobiana oral.The copaiba oil (Copaifera officinalis) potential was evaluated in preventing periodontal disease and reducing its etiology. For that 18 mongrel dogs were homogeneously distributed in three groups: test (copaiba oil), positive control (chlorexidine) and negative control. The treatments were carried out three times a day, during eight days. On the 9th day, the animals were tested with a 0.5% basic solution of fuchsin for the detection of biofilm. Changes in halitosis and gingivitis were daily observed. In addition, the following laboratory tests were done: inhibition of the adherence of Streptococcus mutans, and plaque forming bacteria antimicrobial assays by the agar diffusion method. The results of the fuchsin test showed that dental plaque reached areas of 53.4±8.8%, 28.5±5.4%, and 22.3±5.3% in the negative control, positive control, and test groups, respectively, showing differences between dogs from the negative control group and dogs from the other two groups (P<0.05). Furthermore, halitosis and gingivitis decreased in the copaiba group animals when compared with the negative group (P<0.05). The results of the attachment inhibition and agar diffusion tests showed that copaiba induced better effects against the microorganisms as compared to the results of the other groups (P<0.05). These findings suggest that copaiba oil may effectively replace chlorexidine for oral antimicrobial therapy and prevention of periodontal disease.FAPEMI

Nongenotoxic Effects And A Reduction Of The Dxr-induced Genotoxic Effects Of Helianthus Annuus Linné (sunflower) Seeds Revealed By Micronucleus Assays In Mouse Bone Marrow

Background: This research evaluated the genotoxicity of oil and tincture of H. annuus L. seeds using the micronucleus assay in bone marrow of mice. The interaction between these preparations and the genotoxic effects of doxorubicin (DXR) was also analysed (antigenotoxicity test) .Methods: Experimental groups were evaluated at 24-48 h post treatment with N-Nitroso-N-ethylurea (positive control - NEU), DXR (chemotherapeutic), NaCl (negative control), a sunflower tincture (THALS) and two sources of sunflower oils (POHALS and FOHALS). Antigenotoxic assays were carried out using the sunflower tincture and oils separately and in combination with NUE or DXR. Results: For THALS, analysis of the MNPCEs showed no significant differences between treatment doses (250-2,000 mg.Kg-1) and NaCl. A significant reduction in MNPCE was observed when THALS (2,000 mg.Kg-1) was administered in combination with DXR (5 mg.Kg-1). For POHALS or FOHALS, analysis of the MNPCEs also showed no significant differences between treatment doses (250-2,000 mg.Kg-1) and NaCl. However, the combination DXR + POHALS (2,000 mg.Kg-1) or DXR + FOHALS (2,000 mg.Kg-1) not contributed to the MNPCEs reduction. Conclusions: This research suggests absence of genotoxicity of THALS, dose-, time- and sex-independent, and its combination with DXR can reduce the genotoxic effects of DXR. POHALS and FOHALS also showed absence of genotoxicity, but their association with DXR showed no antigenotoxic effects. © 2014 Boriollo et al.; licensee BioMed Central Ltd.14Sunflowers: Helianthus (Compositae-Heliantheae) (1976) Evolution of Crop Plants, pp. 36-38. , London: Longmans Green, Simmonds NW, Heiser CBEarle, F.R., Vanetten, C.H., Clark, T.F., Wolff, I.A., Compositional data on sunflower seed (1968) J Am Oil Chem Soc, 45, pp. 876-879Salunkhe, D.K., Chavan, J.K., Adsule, R.N., Kadam, S.S., World Oilseeds: Chemistry, Technology and Utilization (1992) Sunflower, , New York: Van Nostrand ReinholdGonzáles-Pérez, S., Vereijken, J.M., Sunflower proteins: Overview of their physicochemical, structural and functional properties (2007) J Sci Food Agric, 87, pp. 2173-2191Warner, K.A., Mounts, T.L., List, G.V.R., Effects of added tocopherols on the flavor stability of purified vegetable oils (1990) Inform, 1, p. 326Ito, T., Tamura, T., Matsumoto, T., Sterol Composition of 19 vegetable oils (1973) J Am Oil Chem Soc, 50, pp. 122-125. , 10.1007/BF02633564, 4707293Trost, V.W., Characterization of corn oil, soybean oil and sunflower oil nonpolar material (1989) J Am Oil Chem Soc, 66, pp. 325-333Dupont, H.L., Sullivan, P., Evans, D.G., Vollet, J.J., Ericsson, C.D., Ackerman, P.B., Tjoa, W.S., Prevention of traveler's diarrhea (emporiatric enteritis). Prophylactic administration of subsalicylate bismuth (1980) JAMA, 243, pp. 237-241. , 10.1001/jama.1980.03300290019013, 6985681Cowan, J.C., Key factors and recent advances in the flavor stability of soybean oil (1966) J Am Oil Chem Soc, 43, pp. 300A-302A. , 318A, 320, 10.1007/BF02682424, 5328054Bierenbaum, M.L., Fleischman, A.I., Dun, J., Arnold, J., Possible toxic waste factor in coronary heart disease (1975) Lancet, 1, pp. 1008-1010Purves, D., Harvey, C., Tweats, D., Lumley, C.E., Genotoxity testing: current practices and strategies used by the pharmaceutical industry (1995) Mutagenesis, 10, pp. 297-312. , 10.1093/mutage/10.4.297, 7476265Varanda, E.A., Atividade mutagênica de plantas medicinais (2006) Rev Ciênc Farm Básica Apl, 27, pp. 1-7Mateuca, R., Lombaert, N., Aka, P.V., Decordier, I., Kirsch-Volders, M., Chromosomal changes: induction, detection methods and applicability in human biomonitoring (2006) Biochimie, 88, pp. 1515-1531. , 10.1016/j.biochi.2006.07.004, 16919864Krishna, G., Hayashi, M., In vivo rodent micronucleus assay: protocol, conduct and data interpretation (2000) Mutat Res, 455, pp. 155-166. , 10.1016/S0027-5107(00)00117-2, 11113474(1997) OECD Guideline for the Testing of Chemicals: Bacterial reverse mutation test, p. 471. , Paris, Organisation for Economic Cooperation and Development(1997) OECD Guideline for the Testing of Chemicals: In vitro mammalian chromosome aberration test, p. 473. , Paris, Organisation for Economic Cooperation and Development(1997) OECD Guideline for the Testing of Chemicals: Mammalian erythrocyte micronucleus test, p. 474. , Paris, Organisation for Economic Cooperation and DevelopmentAlves, J.M., Munari, C.C., Neto, M.A.B.M., Furtado, R.A., Senedese, J.M., Bastos, J.K., Tavares, D.C., In vivo protective effect of Copaifera langsdorffii hydroalcoholic extract on micronuclei induction by doxorubicin (2013) J Appl Toxicol, 33, pp. 854-860. , 10.1002/jat.2777, 22611044Indart, A., Viana, M., Clapés, S., Izquierdo, L., Bonet, B., Clastogenic and cytotoxic effects of lipid peroxidation products generated in culinary oils submitted to thermal stress (2007) Food Chem Toxicol, 45, pp. 1963-1967. , 10.1016/j.fct.2007.04.019, 17573172Venkatesh, P., Shantala, B., Jagetia, G.C., Rao, K.K., Baliga, M.S., Modulation of Doxorubicin-Induced Genotoxicity by Aegle marmelos in Mouse Bone Marrow: A Micronucleus Study (2007) Integr Cancer Ther, 6, pp. 42-53. , 10.1177/1534735406298302, 17351026(2010) Farmacopéia Brasileira, Agência Nacional de Vigilância Sanitária - ANVISA/Fundação Oswaldo, , Brasília: Cruz - FIOCRUZ, BrasilSex differences in the micronucleus test (1986) Mutat Res, 172, pp. 151-163. , Collaborative Study Group for the Micronucleus Test (CSGMT)Zambrano, M.A., Targa, H.J., Rabello-Gay, M.N., Physiological saline solutions as a useful tool in micronucleus and metaphase slide preparations (1982) Stain Technol, 57, pp. 48-49Lewi, D.M., Hopp, H.E., Escandon, A.S., Sunflower (Helianthus annuus L.) (2006) Methods Mol Biol, 343, pp. 291-297Heo, J.C., Woo, S.U.K., Kweon, M.A., Park, J.Y., Lee, H.K., Son, M., Rho, J.R., Lee, S.H., Aqueous extract of the Helianthus annuus seed alleviates asthmatic symptoms in vivo (2008) Int J Mol Med Chem, 21, pp. 57-61Cardoso, C.C., Rodrigues, K.L., Pichara, N.L., Dall'Aglio, R., Fiorini, J.E., Fraschini, F., Diana, G.M., Carvalho, J.C.T., Olio di girasole ozonizzato associate ad acido α-lipoico e a lattobacilli: studio pre-clinico dell'azione antiulcerosa, antinfiammatoria e antibatterica (2004) Farmaci, 28, pp. 97-110Ricardo, G.A., Zullyt, Z.R., Yilian, L., Hernández, F., Menéndez, S., Efecto del OLEOZON® frente a lesiones gástricas inducidas por indometacina en ratas (Effect of OLEOZON® on gastric lesions induced by indomethacin in rats) (2007) Revista electrónica de Veterinaria, 8, pp. 1-6Rodrigues, K.L., Cardoso, C.C., Caputo, L.R., Carvalho, J.C., Fiorini, J.E., Schneedorf, J.M., Cicatrizing and antimicrobial properties of an ozonised oil from sunflower seeds (2004) Inflammopharmacology, 3, pp. 261-270Akihisa, T., Yasukawa, K., Oinuma, H., Kasahara, Y., Kimura, Y., Takase, S., Yamanouchi, S., Tamura, T., Triterpene alcohols from the flowers of Compositae and their anti-inflammatory effects (1996) Phytochemistry, 43, pp. 1255-1260. , 10.1016/S0031-9422(96)00343-3, 8987908Rojas-Molina, M., Campos-Sanches, J., Analla, M., Serrano, M., Moraga, A.A., Genotoxicity of vegetable cooking oils in the Drosophila wing spot test (2005) Environ Mol Mutagen, 45, pp. 90-95. , 10.1002/em.20078, 15611939Montero, A.C.R., Carvajal, Y.G., Rodríguez, Z.Z., López, G.F., Mirabal, J.M., Evaluación genotóxica del OLEOZON mediante los ensayos de micronúcleos en medula ósea y sangre periférica de ratón (1998) Revista CENIC: Ciências Biológicas, 29, pp. 200-202Salerno, J.W., Smith, D.E., The use of sesame oil and other vegetable oils in the inhibition of human colon cancer growth in vitro (1991) Anticancer Res, 11, pp. 209-215Cognault, S., Jourdan, M.L., Germain, E., Pitavy, R., Morel, E., Durand, G., Bougnoux, P., Lhuillery, C., Effect of an m-linolenic acid-rich diet on rat mammary tumour growth depends on the dietary oxidative status (2000) Nutr Cancer, 36, pp. 33-41. , 10.1207/S15327914NC3601_6, 10798214Nakayama, M., Ju, H.R., Sugano, M., Hirose, N., Ueki, T., Doi, F., Eynard, A.R., Effect of dietary fat and cholesterol on dimethylbenz [a]-antracene-induced mammary tumorigenesis in Sprague-Dawley rats (1993) Anticancer Res, 13, pp. 691-698La Vecchia, C., Negri, E., Franceschi, S., Decarli, A., Giacosa, A., Lipworth, L., Olive oil, other dietary fats, and the risk of breast cancer (Italy) (1995) Cancer Cause Control, 6, pp. 545-550Rao, G.N., Ney, E., Herbert, R.A., Effect of melatonin and linolenic acid on mammary cancer in transgenic mice with c-neu breast cancer oncogen (2000) Breast Cancer Res, 64, pp. 287-296Burns, C.P., Luttenegger, D.G., Specctor, A.A., Effect of dietary fat saturation on survival of mice with L1210 Leukemia (1978) J Natl Cancer Inst, 61, pp. 513-515Bartsch, H., Nai, J., Owen, R.W., Dietary polyunsaturated fatty acids and cancer of the breast and colorectum: emerging evidence for their role as risk modifiers (1999) Carcinogenesis, 20, pp. 2209-2218. , 10.1093/carcin/20.12.2209, 10590211Boovens, J., Engelbrecht, P., Le Roux, S., Louwrens, C.C., Van der Merwe, C.F., Katzeff, I.E., Some effects of the essential fatty acids linoleic acid and alpha-Linolenic acid and of their metabolites gamma-Linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahesaenoic acid, and of prostaglandins A1 and E1 in the proliferation of human osteogenic sarcoma cells in culture (1984) Prostaglandins Leukot Med, 15, pp. 15-33. , 10.1016/0262-1746(84)90053-2, 6089235Johanning, G.L., Lin, T.Z., Unsaturated fatty acid effects on human breast cancer cell adhesion (1995) Nutr Cancer, 24, pp. 57-66. , 10.1080/01635589509514393, 7491298Newcomer, L.M., King, I.B., Wicklund, K.G., Stanford, J.L., The association of fatty acids with prostate cancer risk (2001) Prostate, 47, pp. 262-268. , 10.1002/pros.1070, 11398173Iwado, H., Naito, M., Hayatsu, H., Genotoxicity and antigenotoxicity of air-borne particulates (1991) Mutat Res, 246, pp. 93-103. , 10.1016/0027-5107(91)90110-A, 1986270Siegel, I., Liu, T.L., Yaghoubzadeh, E., Keskey, T.S., Gleicher, N., Cytotoxic effects of free fatty acids on ascites tumor cells (1987) J Natl Cancer Inst Monographs, 78, pp. 271-277Bégin, L.R., Clement, P.B., Kirk, M.E., Jothy, S., McCaughey, W.T., Ferenczy, A., Aggressive angiomyxoma of pelvic soft parts: a clinicopathologic study of nine cases (1985) Hum Pathol, 16, pp. 621-628. , 10.1016/S0046-8177(85)80112-X, 3997139Ramon, J.M., Bou, R., Romea, S., Alkiza, M.E., Jacas, M., Ribes, J., Oromi, J., Dietary fat intake and prostate cancer risk: a case-control study in Spain (2000) Cancer Cause Control, 11, pp. 679-685DeFlora, S., Ramel, C., Mechanisms of inhibitors of mutagenesis and carcinogenesis: classification and review (1988) Mutat Res, 202, pp. 285-306. , 10.1016/0027-5107(88)90193-5, 3057362Visioli, F., Bellosta, S., Galli, C., Oleuropein, the bitter principle of olives, enhances nitric-oxide production by mouse macrophages (1998) Life Sci, 62, pp. 541-546. , 10.1016/S0024-3205(97)01150-8, 9464466Santos, J.H., Graf, U., Reguly, M.L., De Andrade, H.H.R., The synergistic effects of vanillin on recombination predominate over its antigenotoxic action in relation to MMC-induced lesions in somatic cells of Drosophila melanogaster (1999) Mutat Res, 444, pp. 355-365. , 10.1016/S1383-5718(99)00101-1, 10521675Weisburger, J.H., Can cancer risks be altered by changing nutritional traditions? (1998) Cancer, 83, pp. 1278-1281. , 10.1002/(SICI)1097-0142(19981001)83:73.0.CO;2-F, 9762926Katiyar, S.K., Mohan, R.R., Agarwal, R., Mukhtar, H., Protection against induction of mouse skin papillomas with low and high risk of conversion to malignancy by green tea polyphenols (1997) Carcinogenesis, 18, pp. 497-502. , 10.1093/carcin/18.3.497, 9067548Indart, A., Viana, M., Grootveld, M.C., Silwood, C.J., Sanchez-Vera, I., Bonet, B., Teratogenic actions of thermally-stressed culinary oils in rats (2002) Free Radic Res Commun Commun, 36, pp. 1051-1058Al-Shabanah, O.A., Inhibition of adriamycin-induced micronuclei by desferrioxamine in Swiss albino mice (1993) Mutat Res, 301, pp. 107-111. , 10.1016/0165-7992(93)90032-Q, 7678167Bean, C.L., Armstrong, M.J., Galloway, S.M., Effect of sampling time on chromosome aberration yield for 7 chemicals in Chinese hamster ovary cells (1992) Mutat Res, 265, pp. 31-44. , 10.1016/0027-5107(92)90037-3, 1370241Delvaeye, M., Verovski, V., De Neve, W., Storme, G., DNA breakage, cytotoxicity, drug accumulation and retention in two human ovarian tumor cell lines AZ224 and AZ364 treated with adriamycin, modulated by verapamil (1993) Anticancer Res, 13, pp. 1533-1538Dhawan, A., Kayani, M.A., Parry, J.M., Parry, E., Anderson, D., Aneugenic and clastogenic effects of doxorubicin in human lymphocytes (2003) Mutagenesis, 18, pp. 487-490. , 10.1093/mutage/geg024, 14614182Jagetia, G.C., Nayak, V., Effect of doxorubicin on cell survival and micronuclei formation in HeLa cells exposed to different doses of gamma-radiation (2000) Strahlenther Onkol, 176, pp. 422-428. , 10.1007/PL00002351, 11050916Vidhya, N., Devraj, S.N., Antioxidant effect of eugenol in rat intestine (1999) Ind J Exp Biol, 37, pp. 1192-119

Cutting Down the Energy Consumed by Domestic Robots: Insights from Robotic Vacuum Cleaners

The market of domestic service robots, and especially vacuum cleaners, has kept growing during the past decade. According to the International Federation of Robotics, more than 1 million units were sold worldwide in 2010. Currently, there is no in-depth analysis of the energetic impact of the introduction of this technology on the mass market. This topic is of prime importance in our energy-dependant society. This study aims at identifying key technologies leading to the reduction of the energy consumption of a domestic mobile robot, by exploring the design space using technologies issued from the robotic research field, such as the various localization and navigation strategies. This approach is validated through an in-depth analysis of seven vacuum cleaning robots. These results are used to build a global assessment of the influential parameters. The major outcome is the assessment of the positive impact of both the ceiling-based visual localization and the laser-based localization approaches

Measurements of long-range near-side angular correlations in sNN=5\sqrt{s_{\text{NN}}}=5TeV proton-lead collisions in the forward region

Two-particle angular correlations are studied in proton-lead collisions at a nucleon-nucleon centre-of-mass energy of $\sqrt{s_{\text{NN}}}=5$TeV, collected with the LHCb detector at the LHC. The analysis is based on data recorded in two beam configurations, in which either the direction of the proton or that of the lead ion is analysed. The correlations are measured in the laboratory system as a function of relative pseudorapidity, $\Delta\eta$, and relative azimuthal angle, $\Delta\phi$, for events in different classes of event activity and for different bins of particle transverse momentum. In high-activity events a long-range correlation on the near side, $\Delta\phi \approx 0$, is observed in the pseudorapidity range $2.0<\eta<4.9$. This measurement of long-range correlations on the near side in proton-lead collisions extends previous observations into the forward region up to $\eta=4.9$. The correlation increases with growing event activity and is found to be more pronounced in the direction of the lead beam. However, the correlation in the direction of the lead and proton beams are found to be compatible when comparing events with similar absolute activity in the direction analysed.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-040.htm

Study of the production of Λb0\Lambda_b^0 and B‾0\overline{B}^0 hadrons in pppp collisions and first measurement of the Λb0→J/ψpK−\Lambda_b^0\rightarrow J/\psi pK^- branching fraction

The product of the $\Lambda_b^0$ ($\overline{B}^0$) differential production cross-section and the branching fraction of the decay $\Lambda_b^0\rightarrow J/\psi pK^-$ ($\overline{B}^0\rightarrow J/\psi\overline{K}^*(892)^0$) is measured as a function of the beauty hadron transverse momentum, $p_{\rm T}$, and rapidity, $y$. The kinematic region of the measurements is $p_{\rm T}<20~{\rm GeV}/c$ and $2.0<y<4.5$. The measurements use a data sample corresponding to an integrated luminosity of $3~{\rm fb}^{-1}$ collected by the LHCb detector in $pp$ collisions at centre-of-mass energies $\sqrt{s}=7~{\rm TeV}$ in 2011 and $\sqrt{s}=8~{\rm TeV}$ in 2012. Based on previous LHCb results of the fragmentation fraction ratio, $f_{\Lambda_B^0}/f_d$, the branching fraction of the decay $\Lambda_b^0\rightarrow J/\psi pK^-$ is measured to be \begin{equation*} \mathcal{B}(\Lambda_b^0\rightarrow J/\psi pK^-)= (3.17\pm0.04\pm0.07\pm0.34^{+0.45}_{-0.28})\times10^{-4}, \end{equation*} where the first uncertainty is statistical, the second is systematic, the third is due to the uncertainty on the branching fraction of the decay $\overline{B}^0\rightarrow J/\psi\overline{K}^*(892)^0$, and the fourth is due to the knowledge of $f_{\Lambda_b^0}/f_d$. The sum of the asymmetries in the production and decay between $\Lambda_b^0$ and $\overline{\Lambda}_b^0$ is also measured as a function of $p_{\rm T}$ and $y$. The previously published branching fraction of $\Lambda_b^0\rightarrow J/\psi p\pi^-$, relative to that of $\Lambda_b^0\rightarrow J/\psi pK^-$, is updated. The branching fractions of $\Lambda_b^0\rightarrow P_c^+(\rightarrow J/\psi p)K^-$ are determined.Comment: 29 pages, 19figures. All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-032.htm

Evidence for the strangeness-changing weak decay Ξb−→Λb0π−\Xi_b^-\to\Lambda_b^0\pi^-

Using a $pp$ collision data sample corresponding to an integrated luminosity of 3.0~fb$^{-1}$, collected by the LHCb detector, we present the first search for the strangeness-changing weak decay $\Xi_b^-\to\Lambda_b^0\pi^-$. No $b$ hadron decay of this type has been seen before. A signal for this decay, corresponding to a significance of 3.2 standard deviations, is reported. The relative rate is measured to be ${{f_{\Xi_b^-}}\over{f_{\Lambda_b^0}}}{\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-) = (5.7\pm1.8^{+0.8}_{-0.9})\times10^{-4}$, where $f_{\Xi_b^-}$ and $f_{\Lambda_b^0}$ are the $b\to\Xi_b^-$ and $b\to\Lambda_b^0$ fragmentation fractions, and ${\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-)$ is the branching fraction. Assuming $f_{\Xi_b^-}/f_{\Lambda_b^0}$ is bounded between 0.1 and 0.3, the branching fraction ${\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-)$ would lie in the range from $(0.57\pm0.21)\%$ to $(0.19\pm0.07)\%$.Comment: 7 pages, 2 figures, All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-047.htm

BB flavour tagging using charm decays at the LHCb experiment

An algorithm is described for tagging the flavour content at production of neutral $B$ mesons in the LHCb experiment. The algorithm exploits the correlation of the flavour of a $B$ meson with the charge of a reconstructed secondary charm hadron from the decay of the other $b$ hadron produced in the proton-proton collision. Charm hadron candidates are identified in a number of fully or partially reconstructed Cabibbo-favoured decay modes. The algorithm is calibrated on the self-tagged decay modes $B^+ \to J/\psi \, K^+$ and $B^0 \to J/\psi \, K^{*0}$ using $3.0\mathrm{\,fb}^{-1}$ of data collected by the LHCb experiment at $pp$ centre-of-mass energies of $7\mathrm{\,TeV}$ and $8\mathrm{\,TeV}$. Its tagging power on these samples of $B \to J/\psi \, X$ decays is $(0.30 \pm 0.01 \pm 0.01) \%$.Comment: All figures and tables, along with any supplementary material and additional information, are available at http://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-027.htm

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters