631 research outputs found
Measurement of the Top Quark Mass Simultaneously in Dilepton and Lepton + Jets Decay Channels
No full textThe authors present the first measurement of the top quark mass using simultaneously data from two decay channels. They use a data sample of {radical}s = 1.96 TeV collisions with integrated luminosity of 1.9 fb{sup -1} collected by the CDF II detector. They select dilepton and lepton + jets channel decays of t{bar t} pairs and reconstruct two observables in each topology. They use non-parametric techniques to derive probability density functions from simulated signal and background samples. The observables are the reconstructed top quark mass and the scalar sum of transverse energy of the event in the dilepton topology and the reconstructed top quark mass and the invariant mass of jets from the W boson decay in lepton + jets channel. They perform a simultaneous fit for the top quark mass and the jet energy scale which is constrained in situ by the hadronic W boson resonance from the lepton + jets channel. Using 144 dilepton candidate events and 332 lepton + jets candidate events they measure: M{sub top} = 171.9 {+-} 1.7 (stat. + JES) {+-} 1.1 (other sys.) GeV/c{sup 2} = 171.9 {+-} 2.0 GeV/c{sup 2}. The measurement features a robust treatment of the systematic uncertainties, correlated between the two channels and develops techniques for a future top quark mass measurement simultaneously in all decay channels. Measurements of the W boson mass and the top quark mass provide a constraint on the mass of the yet unobserved Higgs boson. The Higgs boson mass implied by measurement presented here is higher than Higgs boson mass implied by previously published, most precise CDF measurements of the top quark mass in lepton + jets and dilepton channels separately
UGS wells in depleted fields
No full textTyt. z nagłówka.Bibliogr. s. [417].Dostępny również w formie drukowanej.STRESZCZENIE: Podziemne magazyny gazu (PMG) lokalizowane są głównie na sczerpanych złożach węglowodorów lub w kawernach solnych z wykorzystaniem sprawdzonych technik bazujących na osiągnięciach geologii i geofizyki. W niniejszej pracy opisano czerpane złoża ropy naftowej i gazu ziemnego oraz techniki stosowane w PMG na Słowacji. SŁOWA KLUCZOWE: podziemne magazyny gazu. ABSTRACT: The Underground Gas Storage (UGS) facilities are mainly built in hydrocarbon reservoirs (depleted oil and gas fields), in aquifers and also in salt caverns using proven techniques based on the best use of geology and geophysics. From the international perspective, Slovakia plays an important role in the European gas industry. Transporting one-fifth of the natural gas consumed in western European countries, it is one of the largest natural gas transit countries. Before the end of its path across Slovakia, the transported natural gas reaches the Lab UGS facility in the Slovakia. This paper describes oil and gas depleted reservoirs and techniques that apply in the UGS field. KEYWORDS: underground gas storage (UGS), logging, open hole, closed loop system, sand control
Measurement of the helicity fractions of W bosons from top quark decays using fully reconstructed t(t)over-bar events with CDF II
No full textWe present a measurement of the fractions F-0 and F+ of longitudinally polarized and right-handed W bosons in top-quark decays using data collected with the CDF II detector. The data set used in the analysis corresponds to an integrated luminosity of approximately 318 pb(-1). We select t (t) over bar candidate events with one lepton, at least four jets, and missing transverse energy. Our helicity measurement uses the decay angle theta(*), which is defined as the angle between the momentum of the charged lepton in the W boson rest frame and the W momentum in the top-quark rest frame. The cos theta(*) distribution in the data is determined by full kinematic reconstruction of the t (t) over bar candidates. We find F-0=0.85(-0.22)(+0.15)(stat)+/- 0.06(syst) and F+=0.05(-0.05)(+0.11)(stat)+/- 0.03(syst), which is consistent with the standard model prediction. We set an upper limit on the fraction of right-handed W bosons of F+\u3c 0.26 at the 95% confidence level
Cross section measurements of high-p(T) dilepton final-state processes using a global fitting method
No full textWe present a new method for studying high-p(T) dilepton events (e(+/-)e(-/+), mu(+/-)mu(-/+), e(+/-)mu(-/+)) and simultaneously extracting the production cross sections of p (p) over bar -\u3e t (t) over bar, p (p) over bar -\u3e W+W-, and p (p) over bar -\u3e Z(0) -\u3e tau(+)tau(-) at a center-of-mass energy of root s = 1.96 TeV. We perform a likelihood fit to the dilepton data in a parameter space defined by the missing transverse energy and the number of jets in the event. Our results, which use 360 pb(-1) of data recorded with the CDF II detector at the Fermilab Tevatron Collider, are sigma(t (t) over bar) = 8.5(-2.2)(+2.7) pb, sigma(W+W-) = 16.3(-4.4)(+5.2) pb, and sigma(Z(0) -\u3e tau(+)tau(-)) = 291(-46)(+50) pb
Search for top quark decays t → qH with H → γγ using the ATLAS detector
No full textA search is performed for flavour-changing neutral currents in the decay of a top quark to an up-type (c, u) quark and a Higgs boson, where the Higgs boson decays to two photons. The proton-proton collision data set used corresponds to 4.7 fb-1 at √ = 7TeV and 20.3fb-1 at √ = 8TeV collected by the ATLAS experiment at the LHC. Top quark pair events are searched for in which one top quark decays to qH and the other decays to bW. Both the hadronic and the leptonic decay modes of the W boson are used. No significant signal is observed and an upper limit is set on the t → qH branching ratio of 0.79 at the 95% confidence level. The corresponding limit on the tqH coupling combination λtcH 2 + λtuH 2 is 0.17
Direct measurement of the W boson width in p(p)over-bar collisions at root s=1.96 TeV
No full textA direct measurement of the total decay width of the W boson Gamma(W) is presented using 350 pb(-1) of data from p (p) over bar collisions at root s = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. The width is determined by normalizing predicted signal and background distributions to 230 185 W candidates decaying to e nu and mu nu in the transverse-mass region 50 < M-T < 90 GeV and then fitting the predicted shape to 6055 events in the high-M-T region, 90 < M-T < 200 GeV. The result is Gamma(W) = 2032 +/- 45(stat) +/- 57(syst) MeV, consistent with the standard model expectation
Search for the neutral current top quark decay t→Zc using the ratio of Z-boson+4jets to W-boson+4jets production
No full textAaltonen, T., Adelman, J., Akimoto, T., Alvarez González, B., Amerio, S., Amidei, D., Anastassov, A., Annovi, A., Antos, J., Apollinari, G., Apresyan, A., Arisawa, T., Artikov, A., Ashmanskas, W., Attal, A., Aurisano, A., Azfar, F., Azzurri, P., Badgett, W., Barbaro-Galtieri, A., Barnes, V.E., Barnett, B.A., Bartsch, V., Bauer, G., Beauchemin, P.-H., Bedeschi, F., Beecher, D., Behari, S., Bellettini, G., Bellinger, J., Benjamin, D., Beretvas, A., Beringer, J., Bhatti, A., Binkley, M., Bisello, D., Bizjak, I., Blair, R.E., Blocker, C., Blumenfeld, B., Bocci, A., Bodek, A., Boisvert, V., Bolla, G., Bortoletto, D., Boudreau, J., Boveia, A., Brau, B., Bridgeman, A., Brigliadori, L., Bromberg, C., Brubaker, E., Budagov, J., Budd, H.S., Budd, S., Burke, S., Burkett, K., Busetto, G., Bussey, P., Buzatu, A., Byrum, K.L., Cabrera, S., Calancha, C., Campanelli, M., Campbell, M., Canelli, F., Canepa, A., Carls, B., Carlsmith, D., Carosi, R., Carrillo, S., Carron, S., Casal, B., Casarsa, M., Castro, A., Catastini, P., Cauz, D., Cavaliere, V., Cavalli-Sforza, M., Cerri, A., Cerrito, L., Chang, S.H., Chen, Y.C., Chertok, M., Chiarelli, G., Chlachidze, G., Chlebana, F., Cho, K., Chokheli, D., Chou, J.P., Choudalakis, G., Chuang, S.H., Chung, K., Chung, W.H., Chung, Y.S., Chwalek, T., Ciobanu, C.I., Ciocci, M.A., Clark, A., Clark, D., Compostella, G., Convery, M.E., Conway, J., Cordelli, M., Cortiana, G., Cox, C.A., Cox, D.J., Crescioli, F., Cuenca Almenar, C., Cuevas, J., Culbertson, R., Cully, J.C., Dagenhart, D., Datta, M., Davies, T., De Barbaro, P., De Cecco, S., Deisher, A., De Lorenzo, G., Dell'Orso, M., Deluca, C., Demortier, L., Deng, J., Deninno, M., Derwent, P.F., Di Giovanni, G.P., Dionisi, C., Di Ruzza, B., Dittmann, J.R., D'Onofrio, M., Donati, S., Dong, P., Donini, J., Dorigo, T., Dube, S., Efron, J., Elagin, A., Erbacher, R., Errede, D., Errede, S., Eusebi, R., Fang, H.C., Farrington, S., Fedorko, W.T., Feild, R.G., Feindt, M., Fernandez, J.P., Ferrazza, C., Field, R., Flanagan, G., Forrest, R., Frank, M.J., Franklin, M., Freeman, J.C., Frisch, H.J., Furic, I., Gallinaro, M., Galyardt, J., Garberson, F., Garcia, J.E., Garfinkel, A.F., Genser, K., Gerberich, H., Gerdes, D., Gessler, A., Giagu, S., Giakoumopoulou, V., Giannetti, P., Gibson, K., Gimmell, J.L., Ginsburg, C.M., Giokaris, N., Giordani, M., Giromini, P., Giunta, M., Giurgiu, G., Glagolev, V., Glenzinski, D., Gold, M., Goldschmidt, N., Golossanov, A., Gomez, G., Gomez-Ceballos, G., Goncharov, M., González, O., Gorelov, I., Goshaw, A.T., Goulianos, K., Gresele, A., Grinstein, S., Grosso-Pilcher, C., Group, R.C., Grundler, U., Guimaraes Da Costa, J., Gunay-Unalan, Z., Haber, C., Hahn, K., Hahn, S.R., Halkiadakis, E., Han, B.-Y., Han, J.Y., Happacher, F., Hara, K., Hare, D., Hare, M., Harper, S., Harr, R.F., Harris, R.M., Hartz, M., Hatakeyama, K., Hays, C., Heck, M., Heijboer, A., Heinemann, B., Heinrich, J., Henderson, C., Herndon, M., Heuser, J., Hewamanage, S., Hidas, D., Hill, C.S., Hirschbuehl, D., Hocker, A., Hou, S., Houlden, M., Hsu, S.-C., Huffman, B.T., Hughes, R.E., Husemann, U., Hussein, M., Huston, J., Incandela, J., Introzzi, G., Iori, M., Ivanov, A., James, E., Jang, D., Jayatilaka, B., Jeon, E.J., Jha, M.K., Jindariani, S., Johnson, W., Jones, M., Joo, K.K., Jun, S.Y., Jung, J.E., Junk, T.R., Kamon, T., Kar, D., Karchin, P.E., Kato, Y., Kephart, R., Keung, J., Khotilovich, V., Kilminster, B., Kim, D.H., Kim, H.S., Kim, H.W., Kim, J.E., Kim, M.J., Kim, S.B., Kim, S.H., Kim, Y.K., Kimura, N., Kirsch, L., Klimenko, S., Knuteson, B., Ko, B.R., Kondo, K., Kong, D.J., Konigsberg, J., Korytov, A., Kotwal, A.V., Kreps, M., Kroll, J., Krop, D., Krumnack, N., Kruse, M., Krutelyov, V., Kubo, T., Kuhr, T., Kulkarni, N.P., Kurata, M., Kwang, S., Laasanen, A.T., Lami, S., Lammel, S., Lancaster, M., Lander, R.L., Lannon, K., Lath, A., Latino, G., Lazzizzera, I., Lecompte, T., Lee, E., Lee, H.S., Lee, S.W., Leone, S., Lewis, J.D., Lin, C.-S., Linacre, J., Lindgren, M., Lipeles, E., Lister, A., Litvintsev, D.O., Liu, C., Liu, T., Lockyer, N.S., Loginov, A., Loreti, M., Lovas, L., Lucchesi, D., Luci, C., Lueck, J., Lujan, P., Lukens, P., Lungu, G., Lyons, L., Lys, J., Lysak, R., MacQueen, D., Madrak, R., Maeshima, K., Makhoul, K., Maki, T., Maksimovic, P., Malde, S., Malik, S., Manca, G., Manousakis-Katsikakis, A., Margaroli, F., Marino, C., Marino, C.P., Martin, A., Martin, V., Martínez, M., Martínez-Ballarín, R., Maruyama, T., Mastrandrea, P., Masubuchi, T., Mathis, M., Mattson, M.E., Mazzanti, P., McFarland, K.S., McIntyre, P., McNulty, R., Mehta, A., Mehtala, P., Menzione, A., Merkel, P., Mesropian, C., Miao, T., Miladinovic, N., Miller, R., Mills, C., Milnik, M., Mitra, A., Mitselmakher, G., Miyake, H., Moggi, N., Moon, C.S., Moore, R., Morello, M.J., Morlock, J., Movilla Fernandez, P., Mülmenstädt, J., Mukherjee, A., Muller, Th., Mumford, R., Murat, P., Mussini, M., Nachtman, J., Nagai, Y., Nagano, A., Naganoma, J., Nakamura, K., Nakano, I., Napier, A., Necula, V., Nett, J., Neu, C., Neubauer, M.S., Neubauer, S., Nielsen, J., Nodulman, L., Norman, M., Norniella, O., Nurse, E., Oakes, L., Oh, S.H., Oh, Y.D., Oksuzian, I., Okusawa, T., Orava, R., Osterberg, K., Pagan Griso, S., Palencia, E., Papadimitriou, V., Papaikonomou, A., Paramonov, A.A., Parks, B., Pashapour, S., Patrick, J., Pauletta, G., Paulini, M., Paus, C., Peiffer, T., Pellett, D.E., Penzo, A., Phillips, T.J., Piacentino, G., Pianori, E., Pinera, L., Pitts, K., Plager, C., Pondrom, L., Poukhov, O., Pounder, N., Prakoshyn, F., Pronko, A., Proudfoot, J., Ptohos, F., Pueschel, E., Punzi, G., Pursley, J., Rademacker, J., Rahaman, A., Ramakrishnan, V., Ranjan, N., Redondo, I., Renton, P., Renz, M., Rescigno, M., Richter, S., Rimondi, F., Ristori, L., Robson, A., Rodrigo, T., Rodriguez, T., Rogers, E., Rolli, S., Roser, R., Rossi, M., Rossin, R., Roy, P., Ruiz, A., Russ, J., Rusu, V., Rutherford, B., Saarikko, H., Safonov, A., Sakumoto, W.K., 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S., Tollefson, K., Tomura, T., Tonelli, D., Torre, S., Torretta, D., Totaro, P., Tourneur, S., Trovato, M., Tsai, S.-Y., Tu, Y., Turini, N., Ukegawa, F., Vallecorsa, S., Van Remortel, N., Varganov, A., Vataga, E., Vázquez, F., Velev, G., Vellidis, C., Vidal, M., Vidal, R., Vila, I., Vilar, R., Vine, T., Vogel, M., Volobouev, I., Volpi, G., Wagner, P., Wagner, R.G., Wagner, R.L., Wagner, W., Wagner-Kuhr, J., Wakisaka, T., Wallny, R., Wang, S.M., Warburton, A., Waters, D., Weinberger, M., Weinelt, J., Wester III, W.C., Whitehouse, B., Whiteson, D., Wicklund, A.B., Wicklund, E., Wilbur, S., Williams, G., Williams, H.H., Wilson, P., Winer, B.L., Wittich, P., Wolbers, S., Wolfe, C., Wright, T., Wu, X., Würthwein, F., Xie, S., Yagil, A., Yamamoto, K., Yamaoka, J., Yang, U.K., Yang, Y.C., Yao, W.M., Yeh, G.P., Yoh, J., Yorita, K., Yoshida, T., Yu, G.B., Yu, I., Yu, S.S., Yun, J.C., Zanello, L., Zanetti, A., Zhang, X., Zheng, Y., Zucchelli, S
Search for the Production of Narrow t(b)over-bar Resonances in 1:9 fb(-1) of p(p)over-bar Collisions at root s=1.96 TeV
No full textWe present new limits on resonant t (b) over bar production in p (p) over bar collisions at root s = 1.96 TeV, using 1.9 fb(-1) of data recorded with the CDF II detector at the Fermilab Tevatron. We reconstruct a candidate t (b) over bar mass in events with a lepton, neutrino candidate, and two or three jets, and search for anomalous t (b) over bar production as modeled by W' -> t (b) over bar. We set a new limit on a right-handed W' with standard model-like coupling, excluding any mass below 800 GeV/c(2) at 95% C.L. The cross section for any narrow, resonant t (b) over bar production between 750 and 950 GeV/c(2) is found to be less than 0.28 pb at 95% C. L. We also present an exclusion of the W' coupling strength versus W' mass over the range 300-950 GeV/c(2)
Measurement of the cross section for W-boson production in association with jets in p(p)over-bar collisions at root s=1.96 TeV
No full textWe present a measurement of the cross section for W-boson production in association with jets in p (p) over bar collisions at root s =1.96 TeV. The analysis uses a data sample corresponding to an integrated luminosity of 320 pb(-1) collected with the CDF II detector. W bosons are identified in their electron decay channel and jets are reconstructed using a cone algorithm. For each W+\u3e= n-jet sample (n=1-4) we measure the differential cross section d sigma(p (p) over bar -\u3e W+\u3e= n-jet)/dE(T)(nth-jet)xB(W -\u3e e nu) with respect to the transverse energy E-T of the nth-highest E-T jet above 20 GeV, and the total cross section sigma(p (p) over bar -\u3e W+\u3e= n-jet;E-T(nth-jet)\u3e 25 GeV)xB(W -\u3e e nu), for a restricted W -\u3e e nu decay phase space. The cross sections, corrected for all detector effects, can be directly compared to particle level W+jet(s) predictions. We present here comparisons to leading order and next-to-leading order predictions
Measurement of the t(t)over-bar production cross section in p(p)over-bar collisions at root s=1.96 TeV using missing E-T + jets events with secondary vertex b tagging
No full textWe present a measurement of the t (t) over bar production cross section in p (p) over bar collisions at root s = 1.96 TeV which uses events with an inclusive signature of significant missing transverse energy and jets. This is the first measurement which makes no explicit lepton identification requirements, so that sensitivity to W ->tau nu decays is maintained. Heavy flavor jets from top quark decay are identified with a secondary vertex tagging algorithm. From 311 pb(-1) of data collected by the Collider Detector at Fermilab, we measure a production cross section of 5.8 +/- 1.2(stat)(-0.7)(+0.9)(syst) pb for a top quark mass of 178 GeV/c(2), in agreement with previous determinations and standard model predictions
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