Showing papers by "Victoria Jane Martin published in 2009"

Observation of Electroweak Single Top-Quark Production

Abstract: We report the observation of single top-quark production using 3.2 fb{sup -1} of pp collision data with sq root(s)=1.96 TeV collected by the Collider Detector at Fermilab. The significance of the observed data is 5.0 standard deviations, and the expected sensitivity for standard model production and decay is in excess of 5.9 standard deviations. Assuming m{sub t}=175 GeV/c{sup 2}, we measure a cross section of 2.3{sub -0.5}{sup +0.6}(stat+syst) pb, extract the CKM matrix-element value |V{sub tb}|=0.91+-0.11(stat+syst)+-0.07(theory), and set the limit |V{sub tb}|>0.71 at the 95% C.L.

Search for new particles decaying into dijets in proton-antiproton collisions at s=1.96TeV

Abstract: We present a search for new particles whose decays produce two jets (dijets) using proton-antiproton collision data corresponding to an integrated luminosity of 1.13 fb-1 collected with the CDF II detector. The measured dijet mass spectrum is found to be consistent with next-to-leading-order perturbative QCD predictions, and no significant evidence of new particles is found. We set upper limits at the 95% confidence level on cross sections times the branching fraction for the production of new particles decaying into dijets with both jets having a rapidity magnitude |y| < 1. These limits are used to determine the mass exclusions for the excited quark, axigluon, flavor-universal coloron, E6 diquark, color-octet technirho, W', and Z'.

Direct measurement of the W production charge asymmetry in pp̄ collisions at s=1.96TeV

Abstract: We wish to thank RS Thorne and WJ Stirling for useful discussions on the theoretical predictionsWe thank the Fermilab staff and the technical staffs of the participating institutions for their vital contributions This work was supported by the US Department of Energy and National Science Foundation; the Italian Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Culture, Sports, Science and Technology of Japan; the Natural Sciences and Engineering Research Council of Canada; the National Science Council of the Republic of China; the Swiss National Science Foundation; the AP Sloan Foundation; the Bundesministerium fur Bildung und Forschung, Germany; the Korean Science and Engineering Foundation and the Korean Research Foundation; the Science and Technology Facilities Council and the Royal Society, UK; the Institut National de Physique Nucleaire et Physique des Particules/CNRS; the Russian Foundation for Basic Research; the Comision Interministerial de Ciencia y Tecnologia, Spain; the European Community’s Human Potential Programme; the Slovak RD and the Academy of Finland

Search for high-mass resonances decaying to dimuons at CDF.

Abstract: We present a search for high-mass neutral resonances using dimuon data corresponding to an integrated luminosity of 2.3 fb$^{-1}$ collected in {$p\bar p$} collisions at {$\sqrt{s}$ = 1.96 TeV} by the CDF II detector at the Fermilab Tevatron. No significant excess above the standard model expectation is observed in the dimuon invariant-mass spectrum. We set 95% confidence level upper limits on $\sigma \cdot BR (p \bar{p} \to X \to \mu \bar{\mu})$, where $X$ is a boson with spin 0, 1, or 2. Using these cross section limits, we determine lower mass limits on sneutrinos in R-parity-violating supersymmetric models, $Z'$ bosons, and Kaluza-Klein gravitons in the Randall-Sundrum model.

Global search for new physics with 2.0 fb(-1) at CDF

Abstract: Data collected in run II of the Fermilab Tevatron are searched for indications of new electroweak-scale physics Rather than focusing on particular new physics scenarios, CDF data are analyzed for discrepancies with the standard model prediction A model-independent approach (VISTA) considers gross features of the data, and is sensitive to new large cross-section physics Further sensitivity to new physics is provided by two additional algorithms: a Bump Hunter searches invariant mass distributions for "bumps'' that could indicate resonant production of new particles, and the SLEUTH procedure scans for data excesses at large summed transverse momentum This combined global search for new physics in 20 fb(-1) of p (p) over bar collisions at root s = 196 TeV reveals no indication of physics beyond the standard model

First Measurement of the t(t) over bar Differential Cross Section d sigma/dM(t(t) over bar) in p(p) over bar Collisions at root s=1.96 TeV

Abstract: We present a measurement of the t{bar t} differential cross section with respect to the t{bar t} invariant mass, d{sigma}/dM{sub t{bar t}}, in p{bar p} collisions at {radical}s = 1.96 TeV using an integrated luminosity of 2.7 fb{sup -1} collected by the CDF II experiment. The t{bar t} invariant mass spectrum is sensitive to a variety of exotic particles decaying into t{bar t} pairs. The result is consistent with the standard model expectation, as modeled by PYTHIA with CTEQ5L parton distribution functions.

Search for exclusive Z-boson production and observation of high-mass pp̄→pγγp̄→pl+l-p̄ events in pp̄ collisions at s=1.96TeV

Abstract: We present a search for exclusive Z boson production in proton-antiproton collisions at {radical}s = 1.96 TeV, using the CDF II detector at Fermilab. We observe no exclusive Z {yields} {ell}{sup +}{ell}{sup -} candidates and place the first upper limit on the exclusive Z cross section in hadron collisions, {sigma}{sub excl}(Z) 40 GeV=c{sup 2} and |{eta}{sub {ell}}| < 4 to be {sigma} = 0.24{sub -0.10}{sup +0.13} pb, which is the first measurement for this mass range and is consistent with the standard model prediction.

Observation of the Omega(-)(b) baryon and measurement of the properties of the Xi(-)(b) and Omega(-)(b) baryons

Abstract: The authors report the observation of the bottom, doubly-strange baryon {Omega}{sub b}{sup -} through the decay chain {Omega}{sub b}{sup -} {yields} J/{psi}{Omega}{sup -}, where J/{psi} {yields} {mu}{sup +} {mu}{sup -}, {Omega}{sup -} {yields} {Lambda}K{sup -}, and {Lambda} {yields} p {pi}{sup -}, using 4.2 fb{sup -1} of data from p{bar p} collisions at {radical}s = 1.96 TeV, and recorded with the Collider Detector at Fermilab. A signal is observed whose probability of arising from a background fluctuation is 4.0 x 10{sup -8}, or 5.5 Gaussian standard deviations. The {Omega}{sub b}{sup -} mass is measured to be 6054.4 {+-} 6.8(stat.) {+-} 0.9(syst.) MeV/c{sup 2}. The lifetime of the {Omega}{sub b}{sup -} baryon is measured to be 1.13{sub -0.40}{sup +0.53}(stat.) {+-} 0.02(syst.) ps. In addition, for the {Xi}{sub b}{sup -} baryon they measure a mass of 5790.9 {+-} 2.6(stat.) {+-} 0.8(syst.) MeV/c{sup 2} and a lifetime of 1.56{sub -0.25}{sup +0.27}(stat.) {+-} 0.02(syst.) ps.

Inclusive Search for Squark and Gluino Production in p(p)over-bar Collisions at root s = TeV

Abstract: We report on a search for inclusive production of squarks and gluinos in p{bar p} collisions at {radical}s = 1.96 TeV, in events with large missing transverse energy and multiple jets of hadrons in the final state. The study uses a CDF Run II data sample corresponding to 2 fb-1 of integrated luminosity. The data are in good agreement with the standard model predictions, giving no evidence for any squark or gluino component. In an R-parity conserving minimal supergravity scenario with A{sub 0} = 0, mu < 0 and tan beta = 5, 95% C.L. upper limits on the production cross sections in the range between 0.1 pb and 1 pb are obtained, depending on the squark and gluino masses considered. For gluino masses below 280 GeV/c2, arbitrarily large squark masses are excluded at the 95%C.L., while for mass degenerate gluinos and squarks, masses below 392 GeV/c2 are excluded at the 95% C.L.

Search for High-Mass e(+) e(-) Resonances in p (p)over-bar Collisions at root s=1.96 TeV

Abstract: We thank the Fermilab staff and the technical staffs of the participating institutions for their vital contributions. This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Culture, Sports, Science and Technology of Japan; the Natural Sciences and Engineering Research Council of Canada; the National Science Council of the Republic of China; the Swiss National Science Foundation; the A.P. Sloan Foundation; the Bundesministerium fur Bildung und Forschung, Germany; the Korean Science and Engineering Foundation and the Korean Research Foundation; the Science and Technology Facilities Council and the Royal Society, UK; the Institut National de Physique Nucleaire et Physique des Particules/CNRS; the Russian Foundation for Basic Research; the Ministerio de Ciencia e Innovacion, and Programa Consolider- Ingenio 2010, Spain; the Slovak RD and the Academy of Finland.

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

Abstract: We present new limits on resonant tb production in ppbar collisions at sqrt(s) = 1.96 TeV, using 1.9 fb{sup -1} of data recorded with the CDF II detector at the Fermilab Tevatron. We reconstruct a putative tb mass in events with a lepton, neutrino candidate, and two or three jets, and search for anomalous tb production as modeled by W{prime} {yields} tb. We set a new limit on a right-handed W{prime} with standard model-like coupling, excluding any mass below 800 GeV at 95% C.L. For any narrow W{prime}-like state with mass above 800 GeV, the cross-section is found to be less than 0.28 pb at 95% C.L. We also present an exclusion of the W{prime} coupling strength versus W{prime} mass.

Measurement of Resonance Parameters of Orbitally Excited Narrow B^0 Mesons

Abstract: We report a measurement of resonance parameters of the orbitally excited (L=1) narrow B0 mesons in decays to B;{(*)+}pi;{-} using 1.7 fb;{-1} of data collected by the CDF II detector at the Fermilab Tevatron. The mass and width of the B_{2};{*0} state are measured to be m(B_{2};{*0})=5740.2_{-1.8};{+1.7}(stat)-0.8+0.9(syst) MeV/c;{2} and Gamma(B_{2};{*0})=22.7_{-3.2};{+3.8}(stat)-10.2+3.2(syst) MeV/c;{2}. The mass difference between the B_{2};{*0} and B10 states is measured to be 14.9_{-2.5};{+2.2}(stat)-1.4+1.2(syst) MeV/c;{2}, resulting in a B10 mass of 5725.3_{-2.2};{+1.6}(stat)-1.5+1.4(syst) MeV/c;{2}. This is currently the most precise measurement of the masses of these states and the first measurement of the B_{2};{*0} width.

Observation of new charmless decays of bottom hadrons

Abstract: We search for new charmless decays of neutral b-hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 1 fb-1 of integrated luminosity, we report the first observation of the B0s->K-pi+ decay, with a significance of 8.2 sigma, and measure BR(B0s->K-pi+)= (5.0+-0.7(stat)+-0.8(syst))*10^{-6}. We also report the first observation of charmless b-baryon decays in the channels Lambda_b -> p pi and Lambda_b -> pK with significances of 6.0 sigma and 11.5 sigma respectively, and we measure BR(Lambda_b->p pi-) = (3.5+-0.6(stat)+-0.9(syst))*10^{-6} and BR(Lambda_b->p K-) = (5.6+-0.8(stat)+-1.5(syst))*10^{-6}. No evidence is found for the decays B0->K+K- and B0s -> pi+pi-, and we set an improved upper limit BR(B0s -> pi+pi-) K+pi-)$ as a reference.

Search for the Decays B(s)0→e+μ- and B(s)0→e+e- in CDF Run II

Abstract: We report results from a search for the lepton flavor violating decays $B^0_{(s)}\to e^+\mu^-$, and the flavor-changing neutral-current decays $B^0_{(s)} \to e^+ e^-$. The analysis uses data corresponding to ${\rm 2 fb^{-1}}$ of integrated luminosity of $p \bar{p}$ collisions at $\sqrt{s}=1.96 {\rm TeV}$ collected with the upgraded Collider Detector (CDF II) at the Fermilab Tevatron. The observed number of $B^0_{(s)}$ candidates is consistent with background expectations. The resulting Bayesian upper limits on the branching ratios at 90% credibility level are $\mathcal{B}(B^0_s \to e^{+}\mu^{-}) 47.8 {\rm TeV/c^2}$, and ${M_{LQ}}(B^0\to e^+ \mu^-) > 59.3 {\rm TeV/c^2}$, at 90% credibility level.

Measurement of particle production and inclusive differential cross sections in p(p)over-bar collisions at root s=1.96 TeV

Abstract: We report a set of measurements of particle production in inelastic p (p) over bar collisions collected with a minimum-bias trigger at the Tevatron Collider with the CDF II experiment. The inclusive charged particle transverse momentum differential cross section is measured, with improved precision, over a range about ten times wider than in previous measurements. The former modeling of the spectrum appears to be incompatible with the high particle momenta observed. The dependence of the charged particle transverse momentum on the event particle multiplicity is analyzed to study the various components of hadron interactions. This is one of the observable variables most poorly reproduced by the available Monte Carlo generators. A first measurement of the event transverse energy sum differential cross section is also reported. A comparison with a PYTHIA prediction at the hadron level is performed. The inclusive charged-particle differential production cross section is fairly well reproduced only in the transverse momentum range available from previous measurements. At higher momentum the agreement is poor. The transverse energy sum is poorly reproduced over the whole spectrum. The dependence of the charged particle transverse momentum on the particle multiplicity needs the introduction of more sophisticated particle production mechanisms, such as multiple parton interactions, in order to be better explained.

Measurement of cross sections for b jet production in events with a Z boson in p(p)over-bar collisions at root s=1.96 TeV

Abstract: Aaltonen, T., Adelman, J., Akimoto, T., Gonzalez, B.A.L., 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., Almenar, C.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., 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., Gonzalez, O., Gorelov, I., Goshaw, A.T., Goulianos, K., Gresele, A., Grinstein, S., Grosso-Pilcher, C., Group, R.C., Grundler, U., Da Costa, J.G., 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., Husemann, U., Huston, J., Incandela, J., Introzzi, G., Iori, M., Ivanov, A., James, E., 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., Martinez, M., Martinez-Ballarin, 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., Morlok, J., Fernandez, P.M., Mulmenstadt, J., Mukherjee, A., Muller, T., 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., Griso, S.P., 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., Safonov, A., Sakumoto, W.K., Salto, O., Santi, L., Sarkar, S., Sartori, L., Sato, K., Savoy-Navarro, A., Schlabach, P., Schmidt, A., Schmidt, E.E., Schmidt, M.A., Schmidt, M.P., Schmitt, M., Schwarz, T., Scodellaro, L., Scribano, A., Scuri, F., Sedov, A., Seidel, S., Seiya, Y., Semenov, A., Sexton-Kennedy, L., Sforza, F., Sfyrla, A., Shalhout, S.Z., Shears, T., Shepard, P.F., Shimojima, M., Shiraishi, S., Shochet, M., Shon, Y., Shreyber, I., Sidoti, A., Sinervo, P., Sisakyan, A., Slaughter, A.J., Slaunwhite, J., Sliwa, K., Smith, J.R., Snider, F.D., Snihur, R., Soha, A., Somalwar, S., Sorin, V., Spalding, J., Spreitzer, T., Squillacioti, P., Stanitzki, M., St. Denis, R., Stelzer, B., Stelzer-Chilton, O., Stentz, D., Strologas, J., Strycker, G.L., Stuart, D., Suh, J.S., Sukhanov, A., Suslov, I., Suzuki, T., Taffard, A., Takashima, R., Takeuchi, Y., Tanaka, R., Tecchio, M., Teng, P.K., Terashi, K., Thom, J., Thompson, A.S., Thompson, G.A., Thomson, E., Tipton, P., Ttito-Guzman, P., Tkaczyk, S., Toback, D., Tokar, 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., Vazquez, F., Velev, G., Vellidis, C., Veszpremi, V., 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, 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., Wurthwein, F., Wynne, S.M., 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.

Production of ψ(2S) mesons in pp̄ collisions at 1.96 TeV

Abstract: We have measured the differential cross section for the inclusive production of $\ensuremath{\psi}(2\mathrm{S})$ mesons decaying to ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ that were produced in prompt or $B$-decay processes from $p\overline{p}$ collisions at 1.96 TeV. These measurements have been made using a data set from an integrated luminosity of $1.1\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected by the CDF II detector at Fermilab. For events with transverse momentum ${p}_{T}(\ensuremath{\psi}(2\mathrm{S}))g2\text{ }\text{ }\mathrm{GeV}/c$ and rapidity $|y(\ensuremath{\psi}(2\mathrm{S}))|l0.6$ we measure the integrated inclusive cross section $\ensuremath{\sigma}(p\overline{p}\ensuremath{\rightarrow}\ensuremath{\psi}(2\mathrm{S})X)\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{Br}(\ensuremath{\psi}(2\mathrm{S})\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})$ to be $3.29\ifmmode\pm\else\textpm\fi{}0.04(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.32(\mathrm{syst})\text{ }\text{ }\mathrm{nb}$.

The LCFIVertex package: Vertexing, flavour tagging and vertex charge reconstruction with an ILC vertex detector

Abstract: The precision measurements envisaged at the International Linear Collider (ILC) depend on excellent instrumentation and reconstruction software. The correct identification of heavy flavour jets, placing unprecedented requirements on the quality of the vertex detector, will be central for the ILC programme. This paper describes the LCFIVertex software, which provides tools for vertex finding and for identification of the flavour and charge of the leading hadron in heavy flavour jets. These tools are essential for the ongoing optimisation of the vertex detector design for linear colliders such as the ILC. The paper describes the algorithms implemented in the LCFIVertex package as well as the scope of the code and its performance for a typical vertex detector design.

Measurement of the b-hadron production cross section using decays to μ-D0X final states in pp̄ collisions at s=1.96TeV

Abstract: We report a measurement of the production cross section for b hadrons in p{bar p} collisions at {radical}s = 1.96 TeV. Using a data sample derived from an integrated luminosity 83 pb{sup -1} collected with the upgraded Collider Detector (CDF II) at the Fermilab Tevatron, we analyze b hadrons, H{sub b}, partially reconstructed in the semileptonic decay mode H{sub b} {yields} {mu}{sup -} D{sup 0} X. Our measurement of the inclusive production cross section for b hadrons with transverse momentum p{sub T} > 9 GeV/c and rapidity |y| < 0.6 is {sigma} = 1.30 {micro}b {+-} 0.05 {micro}b(stat) {+-} 0.14 {micro}b(syst) {+-} 0.07 {micro}b({Beta}), where the uncertainties are statistical, systematic, and from branching fractions respectively. The differential cross sections d{sigma}/d{sub T}T are found to be in good agreement with recent measurements of the H{sub b} cross section and well described by fixed-order next-to-leading logarithm predictions.

Top quark mass measurement in the lepton plus jets channel using a modified matrix element method

Abstract: We report a measurement of the top quark mass, m{sub t}, obtained from p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector. We analyze a sample corresponding to an integrated luminosity of 1.9 fb{sup -1}. We select events with an electron or muon, large missing transverse energy, and exactly four high-energy jets in the central region of the detector, at least one of which is tagged as coming from a b quark. We calculate a signal likelihood using a matrix element integration method, where the matrix element is modified by using effective propagators to take into account assumptions on event kinematics. Our event likelihood is a function of m{sub t} and a parameter JES (jet energy scale) that determines in situ the calibration of the jet energies. We use a neural network discriminant to distinguish signal from background events. We also apply a cut on the peak value of each event likelihood curve to reduce the contribution of background and badly reconstructed events. Using the 318 events that pass all selection criteria, we find m{sub t} = 172.7 {+-} 1.8(stat + JES) {+-} 1.2(syst) GeV/c{sup 2}.

First measurement of the ratio of branching fractions B(Λb 0→Λc+μ-ν̄μ)/B(Λb 0→Λc+π-)

Abstract: This article presents the first measurement of the ratio of branching fractions B(Lambda(0)(b) -> Lambda(+)(c) mu(-) (nu) over bar (mu))/B(Lambda(0)(b) -> Lambda(+)(c) pi(-)). Measurements in two control samples using the same technique B((B) over bar (0) -> D+ mu(-) (nu) over bar (mu))/B((B) over bar (0) -> D+ pi(-)) and B((B) over bar (0) -> D*(2010)(+) mu(-) (nu) over bar (mu))/B((B) over bar (0) -> D*(2010)(+) pi(-)) are also reported. The analysis uses data from an integrated luminosity of approximately 172 pb(-1) of p (p) over bar collisions at root s = 1: 96 TeV, collected with the CDF II detector at the Fermilab Tevatron. The relative branching fractions are measured to be B(Lambda(0)(b) -> Lambda(+)(c) mu(-) (nu) over bar (mu))/B(Lambda(0)(b) -> Lambda(+)(c) pi(-)) = 16.6 +/- 3.0(stat) +/- 1.0(syst) (+2.6)(-3.4) (PDG) +/- 0.3(EBR), B((B) over bar (0) -> D+ mu(-) (nu) over bar (mu))/B((B) over bar (0) -> D+ pi(-)) = 9.9 +/- 1.0(stat) +/- 0.6(syst) +/- 0.4(PDG) +/- 0.5(EBR), and B((B) over bar (0)-> D*(2010)(+) mu(-) (nu) over bar (mu))/B((B) over bar (0) -> D*(2010)(+) pi(-)) = 16.5 +/- 2.3(stat) +/- 0.6(syst) +/- 0.5(PDG) +/- 0.8(EBR). The uncertainties are from statistics (stat), internal systematics (syst), world averages of measurements published by the Particle Data Group or subsidiary measurements in this analysis (PDG), and unmeasured branching fractions estimated from theory (EBR), respectively. This article also presents measurements of the branching fractions of four new Lambda(0)(b) semileptonic decays: Lambda(0)(b) -> Lambda(c)(2595)(+) mu(-) (nu) over bar (mu), Lambda(0)(b) -> Lambda(c)(2625)(+) mu(-) (nu) over bar (mu), Lambda(0)(b) -> Sigma(c)(2425)(0) pi(+) mu(-) (nu) over bar (mu) , and Lambda(0)(b) -> Sigma(c)(2455)(++) pi(-) mu(-) (nu) over bar (mu), relative to the branching fraction of the Lambda(0)(b) -> Lambda(+)(c) mu(-) (nu) over bar (mu) decay. Finally, the transverse-momentum distribution of Lambda(0)(b) baryons produced in p (p) over bar collisions is measured and found to be significantly different from that of (B) over bar (0) mesons, which results in a modification in the production crosssection ratio sigma(Lambda b0)/sigma((B) over bar0) with respect to the CDF I measurement.

Measurement of the fraction of t(t)over-bar production via gluon-gluon fusion in p(p)over-bar collisions at root s=1.96 Tev

Abstract: We present a measurement of the ratio of the tt production cross section via gluon-gluon fusion to the total tt production cross section in pp collisions at √s=1.96 TeV at the Tevatron. Using a data sample with an integrated luminosity of 955 pb-1 recorded by the CDF II detector at Fermilab, we select events based on the tt decay to lepton+jets. Using an artificial neural network technique we discriminate between tt events produced via qq annihilation and gg fusion, and find Gf=σ(gg→tt )/σ(pp →tt )<0.33 at the 68% confidence level. This result is combined with a previous measurement to obtain the most stringent measurement of this quantity by CDF to date, Gf=0.07-0.07+0.15.

Search for the rare decays B+→μ+μ-K+, B0→μ+μ- K*(892)0, and Bs0→μ+μ- at CDF

Abstract: We search for b{yields}s{mu}{sup +}{mu}{sup -} transitions in B meson (B{sup +}, B{sup 0}, or B{sub s}{sup 0}) decays with 924 pb{sup -1} of pp collisions at {radical}(s)=1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. We find excesses with significances of 4.5, 2.9, and 2.4 standard deviations in the B{sup +}{yields}{mu}{sup +}{mu}{sup -}K{sup +}, B{sup 0}{yields}{mu}{sup +}{mu}{sup -}K*(892){sup 0}, and B{sub s}{sup 0}{yields}{mu}{sup +}{mu}{sup -}{phi} decay modes, respectively. Using B{yields}J/{psi}h (h=K{sup +}, K*(892){sup 0}, {phi}) decays as normalization channels, we report branching fractions for the previously observed B{sup +} and B{sup 0} decays, B(B{sup +}{yields}{mu}{sup +}{mu}{sup -}K{sup +})=(0.59{+-}0.15{+-}0.04)x10{sup -6}, and B(B{sup 0}{yields}{mu}{sup +}{mu}{sup -}K*(892){sup 0})=(0.81{+-}0.30{+-}0.10)x10{sup -6}, where the first uncertainty is statistical, and the second is systematic. We set an upper limit on the relative branching fraction B(B{sub s}{sup 0}{yields}{mu}{sup +}{mu}{sup -}{phi})/B(B{sub s}{sup 0}{yields}J/{psi}{phi})<2.6(2.3)x10{sup -3} at the 95(90)% confidence level, which is the most stringent to date.

First observation of vector boson pairs in a hadronic final state at the tevatron collider.

Abstract: We present the first observation in hadronic collisions of the electroweak production of vector boson pairs (VV, V = W,Z) where one boson decays to a dijet final state. The data correspond to 3.5 fb{sup -1} of integrated luminosity of p{bar p} collisions at {radical}s = 1.96 TeV collected by the CDF II detector at the Fermilab Tevatron. We observe 1516 {+-} 239(stat) {+-} 144(syst) diboson candidate events and measure a cross section {sigma}(p{bar p} {yields} VV + X) of 18.0 {+-} 2.8(stat) {+-} 2.4(syst) {+-} 1.1(lumi) pb, in agreement with the expectations of the standard model.

Search for a Higgs Boson Decaying to Two W Bosons at CDF

Abstract: We present a search for a Higgs boson decaying to two W bosons in p{bar p} collisions at {radical}s = 1.96 TeV center-of-mass energy. The data sample corresponds to an integrated luminosity of 3.0 fb{sup -1} collected with the CDF II detector. We find no evidence for production of a Higgs boson with mass between 110 and 200 GeV/c{sup 2}, and determine upper limits on the production cross section. For the mass of 160 GeV/c{sup 2}, where the analysis is most sensitive, the observed (expected) limit is 0.7 pb (0.9 pb) at 95% Bayesian credibility level which is 1.7 (2.2) times the standard model cross section.

Search for a standard model Higgs boson in WH→ℓ vbb̄ in pp̄ collisions at s=1.96TeV

Abstract: We present a search for a standard model Higgs boson produced in association with a W boson using 2.7 fb(-1) of integrated luminosity of pp collision data taken at square root s = 1.96 TeV. Limits on the Higgs boson production rate are obtained for masses between 100 and 150 GeV/c(2). Through the use of multivariate techniques, the analysis achieves an observed (expected) 95% confidence level upper limit of 5.6 (4.8) times the theoretically expected production cross section for a standard model Higgs boson with a mass of 115 GeV/c(2).

First simultaneous measurement of the top quark mass in the lepton + jets and dilepton channels at CDF

Abstract: We present a measurement of the mass of the top quark using data corresponding to an integrated luminosity of 1.9 fb{sup -1} of pp collisions collected at {radical}(s)=1.96 TeV with the CDF II detector at Fermilab's Tevatron. This is the first measurement of the top quark mass using top-antitop pair candidate events in the lepton+jets and dilepton decay channels simultaneously. We reconstruct two observables in each channel and use a nonparametric kernel density estimation technique to derive two-dimensional probability density functions from simulated signal and background samples. The observables are the top quark mass and the invariant mass of two jets from the W decay in the lepton+jets channel, and the top quark mass and the scalar sum of transverse energy of the event in the dilepton channel. We perform a simultaneous fit for the top quark mass and the jet energy scale, which is constrained in situ by the hadronic W boson mass. Using 332 lepton+jets candidate events and 144 dilepton candidate events, we measure the top quark mass to be M{sub top}=171.9{+-}1.7(stat+JES){+-}1.1(other syst) GeV/c{sup 2}=171.9{+-}2.0 GeV/c{sup 2}.

Measurement of the inclusive isolated prompt photon cross section in pp̄ collisions at s=1.96TeV using the CDF detector

Abstract: A measurement of the cross section for the inclusive production of isolated photons by the CDF experiment at the Fermilab Tevatron collider is presented. The measurement covers the pseudorapidity region $|{\ensuremath{\eta}}^{\ensuremath{\gamma}}|l1.0$ and the transverse energy range ${E}_{T}^{\ensuremath{\gamma}}g30\text{ }\text{ }\mathrm{GeV}$ and is based on $2.5\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of integrated luminosity. The sample is almost a factor of 7 larger than those used for recent published results and extends the ${E}_{T}^{\ensuremath{\gamma}}$ coverage by 100 GeV. The result agrees with next-to-leading order perturbative QCD calculations within uncertainties over the range $50l{E}_{T}^{\ensuremath{\gamma}}l400\text{ }\text{ }\mathrm{GeV}$, though the energy spectrum in the data shows a steeper slope at lower ${E}_{T}^{\ensuremath{\gamma}}$.