Experimental Mass Limit for a Fourth-Generation Sequential Lepton from<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow><mml:mrow><mml:msup><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mo>−</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:math>Annihilations at<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msqrt><mml:

Kim, Gn; Kim, Eun Jin; Son, D. C.; Bacala, A.; Imlay, R.; Kirk, P.; McNeil, R. R.; Metcalf, W.; Cheng, C. P.; Mao, Z. P.; Yan, Yupeng; Xu, Y. T.; Zhu, Y. C.; Abashian, A.; Gotow, K.; Kajino, F.; Low, E. H.; Naito, F.; Piilonen, L. E.; Childers, R.; Darden, C. W.; Lusin, S.; Rosenfeld, C.; Wilson, Stephen; Frautschi, M.; Kagan, H.; Kass, R.; Trahern, C. G.; Ko, W.; Lander, R.; Maeshima, K.; Malchow, R.; Smith, Trevor A.; Sparks, K.; Williams, M. S. C.; Abe, Kazuo; Chakrabarti, S.; Fujii, Y.; Higashi, Y.; Kurihara, Y.; Maki, A.; Nozaki, T.; Omori, T.; Pérez, P.; Sagawa, H.; Sakai, Y.; Sugimoto, Yasuhiro; Takaiwa, Y.; Terada, S.; Tsuchiya, K.; Poling, R.; Green, J; Park, Ih; Sakamoto, S.; Sannes, F.; Schnetzer, S.; Stone, R.; Trentalange, S.; Zimmerman, D.; Miyano, K.; Miyata, H.; Ogawa, Maki; Yamashita, Y.; Blanis, D.; Bodek, A.; Budd, H. S.; Coombes, R.; Eno, S. C.; Fry, C. A.; Harada, Hiroyuki; Ho, Y.; Yk, Kim; Kumita, T.; Mori, T.; Olsen, S. L.; Shaw, N. M.; Sill, A.; Thorndike, E. H.; Ueno, K.; Zheng, H. W.; Asakura, H.; Eguchi, K.; Itoh, H.; Kobayashi, S.; Murakami, Akira; Toyoshima, Kouichi; Kang, J. S.; Kim, Hyung Jun; Sk, Kim; Lee, Moo Hyun; Myung, S. S.; Kozuka, H.; Matsumoto, S.; Sasaki, Takashi; Takeda, Takahito; Tanaka, R.; Chiba, R.; Hanaoka, Ken’ichi; Igarashi, S.; Murata, H.; Yokota, H.; Ishi, Y.; Ishizuka, T.; Ohta, Kouji

doi:10.1103/physrevlett.61.911

Cited by 10 publications

(3 citation statements)

References 17 publications

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“…We consider the decay via mixing of a sequential neutrino 1/ 4 -• IW' as described in Section 2.4. In that section, the proportionality relation Tfa-«-)ocm-s |0i4r a (73) was shown. Although the unitarity of the mixing matrix and e -n, (t -r weak universality restrict the allowed mixings [62], there is a large region where the mixing is of a value such that the decay length of the 1/ 4 is experimentally observable, as in the MC event exhibited To search for this topology, one possibility is to look for events with two back-to-back vertices that are separated from the interaction point and with i'.o tracks coming from the interaction point.…”

Section: Expected Signature and Backgroundmentioning

confidence: 94%

“…Previous searches have set an experimental limit of mi > 30 GeV/c 2 at 95% CL from e + e~ collisions [73], and a less direct limit of mi > 41 GeV/c 2 at 90% CL from pp collision [74] assuming that \>L is mossiest. These limits degrade as vi increases in mass, and [72] contains a comprehensive review of limits with m" L jt 0.…”

Section: Present L~ Mass Limitsmentioning

confidence: 99%

“…Subsequent improved limits by ALEPH [125] are shown as dashed lines. [73], and (3) UA1 [74]. Subsequent improved limits by ALEPH [125] and OPAL (direct search) [138] are shown as dashed lines.…”

Section: Fourth Generation Charged Lepton L~mentioning

confidence: 99%

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Searches for new quarks and leptons in Z boson decays

Kooten¹,

J²

1990

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Price: Printed Copy A08, Microfiche AOl. fAsia * Ph.D. theiif g : "---'-'-r,ow ry r T(1iS ooeu^r ,V.UM P* Abstract Searches for the decay of Z bosons into pairs of new quarks and leptons in a data sample including 455 hadronic Z decays are presented. The Z bosons were produced in electon-positron annihilations at the SLA.C Linear Collider (SLC) operating in the centerof-mass energy range from 89.2 to 93.0 GeV, and the data collected using the Mark II detector. The Standard Model provides no prediction for fermion masses and does not exclude new generations of fennions. The existence and masses of these new particles may provide valuable information to help understand the pattern of fermion masses, the presence of generations, and physics beyond the Standard Model. Specific searches for top quarks and sequential fourth generation charge -1/3 (!/) quarks are made considering a variety of possible standard and non-standard decay modes. In ad dition, searches for sequential fourth generation massive neutrinos v,i (Dirac and Majorana)and their charged lepton partners L~ are pursued. The i/ 4 may be stable or decay through mixing to the lighter generations. The data sample Is examined for new particle topolo gies of events with high-momentum isolated tracks, high-energy isolated photons, spherical event shapes, and detached vertices. Measurements of the Z boson resonance parameters that provide crucial indicators of new particle production are also considered.No evidence is observed for the production of new quarks and leptons. 95% confidence lower mass limits of 40.7 GeV/c 2 for the top quark and 42.0 GeV/c 2 for the t'-quark mass are obtained regardless of the branching fractions to the considered decay modes. A significant range of mixing matrix elements of v.\ to other generation neutrinos for a v A mass from 1 GeV/c 2 to 43 GeV/c 2 is excluded at 95% confidence level. Measurements of the upper limit of the invisible width of the Z exclude additional values of the u 4 mass and mixing matrix elements, and also permit the exclusion of a region in the L~ mass versus v.\ mass plane.ii These results substantially extend previous limits, and exclude a large fraction of the *.mass range available for Z decays into top quarks and fourth generation quarks and leptons. #"This thesis analysis benefited greatly from illuminating and helpful discussions with several people. The enthusiasm and energy of Tim Barklow, the knowledge of Sachio Komamiya, and the wisdom of a close friend, Chang-Kee Jung have been a source of inspiration for me.I would like to thank the Mark II collaborators for their contributions during the some times frustrating operation of the Mark II detector at the SLC. I am just as grateful for the camaraderie and friendship of my colleagues. My office mates Carrie Fordham and graduate student (now post-doc) extraordinaire, Jordan Nash, provided many interesting conversations and company. , and others too numerous to name have all made for a great experience. I extend my thanks to Anna Pacheco for the countless...

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Section: Expected Signature and Backgroundmentioning

confidence: 94%

Section: Present L~ Mass Limitsmentioning

confidence: 99%

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Searches for new quarks and leptons in Z boson decays

Kooten¹,

J²

1990

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New Results from High Energy e + e - Experiments

Kamae

1989

XXIV International Conference on High Energy Physics

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Factors Influencing Farmers’ Willingness to Participate in the Conversion of Cultivated Land to Wetland Program in Sanjiang National Nature Reserve, China

Zhang

Robinson

Jing

et al. 2010

Environmental Management

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Sanjiang National Nature Reserve (NNR) is a state-owned natural wetland in China that has suffered severe degradation due to cultivation and wetland reclamation by farmers. As a consequence, the conversion of cultivated land to wetlands (CCW) was proposed by the government of Heilongjiang province and the United Nations Development Programme/Global Environment Facility (UNDP/GEF) project team in 2007. We suggest that voluntary participation in the CCW could be an important tool for accomplishing the integrated objectives of wetland conservation and local development. The purpose of this study was to examine the main factors that influence farmers' willingness to participate in the CCW through a field investigation and a questionnaire. Based on the data from our questionnaire, which provided an effective sample of 310 households in 11 villages, the influencing factors of farmers' willingness to participate were analyzed through binary logistic regression analyses. It was concluded that age, education, the amount of cultivated land, geographical location, and the perceived benefits and risks were important factors for participation. Furthermore, suggestions for improving the wetland compensation system and providing alternative livelihoods are proposed to strengthen participation.

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Experimental Mass Limit for a Fourth-Generation Sequential Lepton frome+e−Annihilations at

Cited by 10 publications

References 17 publications

Searches for new quarks and leptons in Z boson decays

Searches for new quarks and leptons in Z boson decays

New Results from High Energy e + e - Experiments

Factors Influencing Farmers’ Willingness to Participate in the Conversion of Cultivated Land to Wetland Program in Sanjiang National Nature Reserve, China

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