Measurement of the Lambda b lifetime in the exclusive decay Lambda b --> J/psi Lambda.

Phys Rev Lett 99:14 (2007) 142001

Authors:

VM Abazov, B Abbott, M Abolins, BS Acharya, M Adams, T Adams, E Aguilo, SH Ahn, M Ahsan, GD Alexeev, G Alkhazov, A Alton, G Alverson, GA Alves, M Anastasoaie, LS Ancu, T Andeen, S Anderson, B Andrieu, MS Anzelc, Y Arnoud, M Arov, M Arthaud, A Askew, B Asman, ACS Assis Jesus, O Atramentov, C Autermann, C Avila, C Ay, F Badaud, A Baden, L Bagby, B Baldin, DV Bandurin, P Banerjee, S Banerjee, E Barberis, A-F Barfuss, P Bargassa, P Baringer, J Barreto, JF Bartlett, U Bassler, D Bauer, S Beale, A Bean, M Begalli, M Begel, C Belanger-Champagne, L Bellantoni, A Bellavance, JA Benitez, SB Beri, G Bernardi, R Bernhard, L Berntzon, I Bertram, M Besançon, R Beuselinck, VA Bezzubov, PC Bhat, V Bhatnagar, C Biscarat, G Blazey, F Blekman, S Blessing, D Bloch, K Bloom, A Boehnlein, D Boline, TA Bolton, G Borissov, K Bos, T Bose, A Brandt, R Brock, G Brooijmans, A Bross, D Brown, NJ Buchanan, D Buchholz, M Buehler, V Buescher, S Burdin, S Burke, TH Burnett, CP Buszello, JM Butler, P Calfayan, S Calvet, J Cammin, S Caron, W Carvalho, BCK Casey, NM Cason, H Castilla-Valdez, S Chakrabarti, D Chakraborty, K Chan, KM Chan, A Chandra, F Charles, E Cheu, F Chevallier, DK Cho, S Choi, B Choudhary, L Christofek, T Christoudias, S Cihangir, D Claes, B Clément, C Clément, Y Coadou, M Cooke, WE Cooper, M Corcoran, F Couderc, M-C Cousinou, S Crépé-Renaudin, D Cutts, M Cwiok, H da Motta, A Das, G Davies, K De, P de Jong, SJ de Jong, E De La Cruz-Burelo, C De Oliveira Martins, JD Degenhardt, F Déliot, M Demarteau, R Demina, D Denisov, SP Denisov, S Desai, HT Diehl, M Diesburg, A Dominguez, H Dong, LV Dudko, L Duflot, SR Dugad, D Duggan, A Duperrin, J Dyer, A Dyshkant, M Eads, D Edmunds, J Ellison, VD Elvira, Y Enari, S Eno, P Ermolov, H Evans, A Evdokimov, VN Evdokimov, AV Ferapontov, T Ferbel, F Fiedler, F Filthaut, W Fisher, HE Fisk, M Ford, M Fortner, H Fox, S Fu, S Fuess, T Gadfort, CF Galea, E Gallas, E Galyaev, C Garcia, A Garcia-Bellido, V Gavrilov, P Gay, W Geist, D Gelé, CE Gerber, Y Gershtein, D Gillberg, G Ginther, N Gollub, B Gómez, A Goussiou, PD Grannis, H Greenlee, ZD Greenwood, EM Gregores, G Grenier, Ph Gris, J-F Grivaz, A Grohsjean, S Grünendahl, MW Grünewald, F Guo, J Guo, G Gutierrez, P Gutierrez, A Haas, NJ Hadley, P Haefner, S Hagopian, J Haley, I Hall, RE Hall, L Han, K Hanagaki, P Hansson, K Harder, A Harel, R Harrington, JM Hauptman, R Hauser, J Hays, T Hebbeker, D Hedin, JG Hegeman, JM Heinmiller, AP Heinson, U Heintz, C Hensel, K Herner, G Hesketh, MD Hildreth, R Hirosky, JD Hobbs, B Hoeneisen, H Hoeth, M Hohlfeld, SJ Hong, R Hooper, S Hossain, P Houben, Y Hu, Z Hubacek, V Hynek, I Iashvili, R Illingworth, AS Ito, S Jabeen, M Jaffré, S Jain, K Jakobs, C Jarvis, R Jesik, K Johns, C Johnson, M Johnson, A Jonckheere, P Jonsson, A Juste, D Käfer, S Kahn, E Kajfasz, AM Kalinin, JM Kalk, JR Kalk, S Kappler, D Karmanov, J Kasper, P Kasper, I Katsanos, D Kau, R Kaur, V Kaushik, R Kehoe, S Kermiche, N Khalatyan, A Khanov, A Kharchilava, YM Kharzheev, D Khatidze, H Kim, TJ Kim, MH Kirby, M Kirsch, B Klima, JM Kohli, J-P Konrath, M Kopal, VM Korablev, B Kothari, AV Kozelov, D Krop, A Kryemadhi, T Kuhl, A Kumar, S Kunori, A Kupco, T Kurca, J Kvita, D Lam, S Lammers, G Landsberg, J Lazoflores, P Lebrun, WM Lee, A Leflat, F Lehner, J Lellouch, V Lesne, J Leveque, P Lewis, J Li, L Li, QZ Li, SM Lietti, JGR Lima, D Lincoln, J Linnemann, VV Lipaev, R Lipton, Y Liu, Z Liu, L Lobo, A Lobodenko, M Lokajicek, A Lounis, P Love, HJ Lubatti, AL Lyon, AKA Maciel, D Mackin, RJ Madaras, P Mättig, C Magass, A Magerkurth, N Makovec, PK Mal, HB Malbouisson, S Malik, VL Malyshev, HS Mao, Y Maravin, B Martin, R McCarthy, A Melnitchouk, A Mendes, L Mendoza, PG Mercadante, M Merkin, KW Merritt, A Meyer, J Meyer, M Michaut, T Millet, J Mitrevski, J Molina, RK Mommsen, NK Mondal, RW Moore, T Moulik, GS Muanza, M Mulders, M Mulhearn, O Mundal, L Mundim, E Nagy, M Naimuddin, M Narain, NA Naumann, HA Neal, JP Negret, P Neustroev, H Nilsen, C Noeding, A Nomerotski, SF Novaes, T Nunnemann, V O'dell, DC O'neil, G Obrant, C Ochando, D Onoprienko, N Oshima, J Osta, R Otec, GJ Otero Y Garzón, M Owen, P Padley, M Pangilinan, N Panikashvili, N Parashar, S-J Park, SK Park, J Parsons, R Partridge, N Parua, A Patwa, G Pawloski, PM Perea, K Peters, Y Peters, P Pétroff, M Petteni, R Piegaia, J Piper, M-A Pleier, PLM Podesta-Lerma, VM Podstavkov, Y Pogorelov, M-E Pol, A Pompos, BG Pope, AV Popov, C Potter, WL Prado da Silva, HB Prosper, S Protopopescu, J Qian, A Quadt, B Quinn, A Rakitine, MS Rangel, KJ Rani, K Ranjan, PN Ratoff, P Renkel, S Reucroft, P Rich, M Rijssenbeek, I Ripp-Baudot, F Rizatdinova, S Robinson, RF Rodrigues, C Royon, P Rubinov, R Ruchti, G Safronov, G Sajot, A Sánchez-Hernández, MP Sanders, A Santoro, G Savage, L Sawyer, T Scanlon, D Schaile, RD Schamberger, Y Scheglov, H Schellman, P Schieferdecker, T Schliephake, C Schmitt, C Schwanenberger, A Schwartzman, R Schwienhorst, J Sekaric, S Sengupta, H Severini, E Shabalina, M Shamim, V Shary, AA Shchukin, RK Shivpuri, D Shpakov, V Siccardi, V Simak, V Sirotenko, P Skubic, P Slattery, D Smirnov, RP Smith, GR Snow, J Snow, S Snyder, S Söldner-Rembold, L Sonnenschein, A Sopczak, M Sosebee, K Soustruznik, M Souza, B Spurlock, J Stark, J Steele, V Stolin, A Stone, DA Stoyanova, J Strandberg, S Strandberg, MA Strang, M Strauss, R Ströhmer, D Strom, M Strovink, L Stutte, S Sumowidagdo, P Svoisky, A Sznajder, M Talby, P Tamburello, A Tanasijczuk, W Taylor, P Telford, J Temple, B Tiller, F Tissandier, M Titov, VV Tokmenin, M Tomoto, T Toole, I Torchiani, T Trefzger, D Tsybychev, B Tuchming, C Tully, PM Tuts, R Unalan, L Uvarov, S Uvarov, S Uzunyan, B Vachon, PJ van den Berg, B van Eijk, R Van Kooten, WM van Leeuwen, N Varelas, EW Varnes, A Vartapetian, IA Vasilyev, M Vaupel, P Verdier, LS Vertogradov, M Verzocchi, F Villeneuve-Seguier, P Vint, E Von Toerne, M Voutilainen, M Vreeswijk, R Wagner, HD Wahl, L Wang, MHLS Wang, J Warchol, G Watts, M Wayne, G Weber, M Weber, H Weerts, A Wenger, N Wermes, M Wetstein, A White, D Wicke, GW Wilson, SJ Wimpenny, M Wobisch, DR Wood, TR Wyatt, Y Xie, S Yacoob, R Yamada, M Yan, T Yasuda, YA Yatsunenko, K Yip, HD Yoo, SW Youn, C Yu, J Yu, A Yurkewicz, A Zatserklyaniy, C Zeitnitz, D Zhang, T Zhao, B Zhou, J Zhu, M Zielinski, D Zieminska, A Zieminski, L Zivkovic, V Zutshi, EG Zverev, D0 Collaboration

Abstract:

We have measured the Lambda b lifetime using the exclusive decay Lambda b --> J/psi Lambda, based on 1.2 fb(-1) of data collected with the D0 detector during 2002-2006. From 171 reconstructed Lambda b decays, where the J/psi and Lambda are identified via the decays J/psi --> mu+ mu- and Lambda --> ppi, we measured the Lambda b lifetime to be tau(Lambda b)=1.218 (+0.130)/(-0.115) (stat) +/- 0.042(syst) ps. We also measured the B0 lifetime in the decay B0 --> J/psi(mu+ mu-)K(0)/(S)(pi+ pi-) to be tau(B0)=1.501 (+0.078)/(-0.074) (stat) +/- 0.050(syst) ps, yielding a lifetime ratio of tau(Lambda b)/tau(B0)=0.811 (+0.096)/(-0.087) (stat) +/- 0.034(syst).

Measurement of the Λb lifetime in the exclusive decay Λb→J/ψΛ

Physical Review Letters 99:14 (2007)

Authors:

VM Abazov, B Abbott, M Abolins, BS Acharya, M Adams, T Adams, E Aguilo, SH Ahn, M Ahsan, GD Alexeev, G Alkhazov, A Alton, G Alverson, GA Alves, M Anastasoaie, LS Ancu, T Andeen, S Anderson, B Andrieu, MS Anzelc, Y Arnoud, M Arov, M Arthaud, A Askew, B Åsman, ACSA Jesus, O Atramentov, C Autermann, C Avila, C Ay, F Badaud, A Baden, L Bagby, B Baldin, DV Bandurin, P Banerjee, S Banerjee, E Barberis, AF Barfuss, P Bargassa, P Baringer, J Barreto, JF Bartlett, U Bassler, D Bauer, S Beale, A Bean, M Begalli, M Begel, C Belanger-Champagne, L Bellantoni, A Bellavance, JA Benitez, SB Beri, G Bernardi, R Bernhard, L Berntzon, I Bertram, M Besançon, R Beuselinck, VA Bezzubov, PC Bhat, V Bhatnagar, C Biscarat, G Blazey, F Blekman, S Blessing, D Bloch, K Bloom, A Boehnlein, D Boline, TA Bolton, G Borissov, K Bos, T Bose, A Brandt, R Brock, G Brooijmans, A Bross, D Brown, NJ Buchanan, D Buchholz, M Buehler, V Buescher, S Burdin, S Burke, TH Burnett, CP Buszello, JM Butler, P Calfayan, S Calvet, J Cammin, S Caron, W Carvalho, BCK Casey, NM Cason, H Castilla-Valdez, S Chakrabarti, D Chakraborty, K Chan

Abstract:

We have measured the Λb lifetime using the exclusive decay Λb→J/ψΛ, based on 1.2fb-1 of data collected with the D0 detector during 2002-2006. From 171 reconstructed Λb decays, where the J/ψ and Λ are identified via the decays J/ψ→μ+μ- and Λ→pπ, we measured the Λb lifetime to be τ(Λb)=1.218-0.115+0.130(stat)±0.042(syst)ps. We also measured the B0 lifetime in the decay B0→J/ψ(μ+μ-)KS0(π+π-) to be τ(B0)=1.501-0.074+0.078(stat)±0.050(syst)ps, yielding a lifetime ratio of τ(Λb)/τ(B0)=0.811-0.087+0.096(stat)±0.034(syst). © 2007 The American Physical Society.

Solar probe

Nature Physics Springer Nature 3:10 (2007) 682-684

Measurement of the tt̄ production cross section in pp̄ collisions using dilepton events

Physical Review D - Particles, Fields, Gravitation and Cosmology 76:5 (2007)

Authors:

VM Abazov, B Abbott, M Abolins, BS Acharya, M Adams, T Adams, E Aguilo, SH Ahn, M Ahsan, GD Alexeev, G Alkhazov, A Alton, G Alverson, GA Alves, M Anastasoaie, LS Ancu, T Andeen, S Anderson, B Andrieu, MS Anzelc, Y Arnoud, M Arov, M Arthaud, A Askew, B Åsman, ACSA Jesus, O Atramentov, C Autermann, C Avila, C Ay, F Badaud, A Baden, L Bagby, B Baldin, DV Bandurin, S Banerjee, P Banerjee, E Barberis, AF Barfuss, P Bargassa, P Baringer, J Barreto, JF Bartlett, U Bassler, D Bauer, S Beale, A Bean, M Begalli, M Begel, C Belanger-Champagne, L Bellantoni, A Bellavance, JA Benitez, SB Beri, G Bernardi, R Bernhard, L Berntzon, I Bertram, M Besançon, R Beuselinck, VA Bezzubov, PC Bhat, V Bhatnagar, C Biscarat, G Blazey, F Blekman, S Blessing, D Bloch, K Bloom, A Boehnlein, D Boline, TA Bolton, G Borissov, K Bos, T Bose, A Brandt, R Brock, G Brooijmans, A Bross, D Brown, NJ Buchanan, D Buchholz, M Buehler, V Buescher, S Burdin, S Burke, TH Burnett, CP Buszello, JM Butler, P Calfayan, S Calvet, J Cammin, S Caron, W Carvalho, BCK Casey, NM Cason, H Castilla-Valdez, S Chakrabarti, D Chakraborty, KM Chan

Abstract:

We present a measurement of the tt̄ pair production cross section in pp̄ collisions at s=1.96TeV utilizing approximately 425pb-1 of data collected with the D0 detector. We consider decay channels containing two high pT charged leptons (either e or μ) from leptonic decays of both top-daughter W bosons. These were gathered using four sets of selection criteria, three of which required that a pair of fully identified leptons (i.e., eμ, ee, or μμ) be found. The fourth approach imposed less restrictive criteria on one of the lepton candidates and required that at least one hadronic jet in each event be tagged as containing a b quark. For a top quark mass of 175 GeV, the measured cross section is 7.4±1.4(stat)±1.0(syst)pb and for the current Tevatron average top quark mass of 170.9 GeV, the resulting value of the cross section is 7.8±1.8(stat+syst)pb. © 2007 The American Physical Society.

Search for stopped gluinos from pp collisions at square root s = 1.96 TeV.

Phys Rev Lett 99:13 (2007) 131801

Authors:

VM Abazov, B Abbott, M Abolins, BS Acharya, M Adams, T Adams, E Aguilo, SH Ahn, M Ahsan, GD Alexeev, G Alkhazov, A Alton, G Alverson, GA Alves, M Anastasoaie, LS Ancu, T Andeen, S Anderson, B Andrieu, MS Anzelc, Y Arnoud, M Arov, M Arthaud, A Askew, B Asman, ACS Assis Jesus, O Atramentov, C Autermann, C Avila, C Ay, F Badaud, A Baden, L Bagby, B Baldin, DV Bandurin, P Banerjee, S Banerjee, E Barberis, A-F Barfuss, P Bargassa, P Baringer, J Barreto, JF Bartlett, U Bassler, D Bauer, S Beale, A Bean, M Begalli, M Begel, C Belanger-Champagne, L Bellantoni, A Bellavance, JA Benitez, SB Beri, G Bernardi, R Bernhard, L Berntzon, I Bertram, M Besançon, R Beuselinck, VA Bezzubov, PC Bhat, V Bhatnagar, C Biscarat, G Blazey, F Blekman, S Blessing, D Bloch, K Bloom, A Boehnlein, D Boline, TA Bolton, G Borissov, K Bos, T Bose, A Brandt, R Brock, G Brooijmans, A Bross, D Brown, NJ Buchanan, D Buchholz, M Buehler, V Buescher, S Burdin, S Burke, TH Burnett, CP Buszello, JM Butler, P Calfayan, S Calvet, J Cammin, S Caron, W Carvalho, BCK Casey, NM Cason, H Castilla-Valdez, S Chakrabarti, D Chakraborty, K Chan, KM Chan, A Chandra, F Charles, E Cheu, F Chevallier, DK Cho, S Choi, B Choudhary, L Christofek, T Christoudias, S Cihangir, D Claes, B Clément, C Clément, Y Coadou, M Cooke, WE Cooper, M Corcoran, F Couderc, M-C Cousinou, S Crépé-Renaudin, D Cutts, M Cwiok, H da Motta, A Das, G Davies, K De, P de Jong, SJ de Jong, E De La Cruz-Burelo, C De Oliveira Martins, JD Degenhardt, F Déliot, M Demarteau, R Demina, D Denisov, SP Denisov, S Desai, HT Diehl, M Diesburg, A Dominguez, H Dong, LV Dudko, L Duflot, SR Dugad, D Duggan, A Duperrin, J Dyer, A Dyshkant, M Eads, D Edmunds, J Ellison, VD Elvira, Y Enari, S Eno, P Ermolov, H Evans, A Evdokimov, VN Evdokimov, AV Ferapontov, T Ferbel, F Fiedler, F Filthaut, W Fisher, HE Fisk, M Ford, M Fortner, H Fox, S Fu, S Fuess, T Gadfort, CF Galea, E Gallas, E Galyaev, C Garcia, A Garcia-Bellido, V Gavrilov, P Gay, W Geist, D Gelé, CE Gerber, Y Gershtein, D Gillberg, G Ginther, N Gollub, B Gómez, A Goussiou, PD Grannis, H Greenlee, ZD Greenwood, EM Gregores, G Grenier, Ph Gris, J-F Grivaz, A Grohsjean, S Grünendahl, MW Grünewald, F Guo, J Guo, G Gutierrez, P Gutierrez, A Haas, NJ Hadley, P Haefner, S Hagopian, J Haley, I Hall, RE Hall, L Han, K Hanagaki, P Hansson, K Harder, A Harel, R Harrington, JM Hauptman, R Hauser, J Hays, T Hebbeker, D Hedin, JG Hegeman, JM Heinmiller, AP Heinson, U Heintz, C Hensel, K Herner, G Hesketh, MD Hildreth, R Hirosky, JD Hobbs, B Hoeneisen, H Hoeth, M Hohlfeld, SJ Hong, R Hooper, S Hossain, P Houben, Y Hu, Z Hubacek, V Hynek, I Iashvili, R Illingworth, AS Ito, S Jabeen, M Jaffré, S Jain, K Jakobs, C Jarvis, R Jesik, K Johns, C Johnson, M Johnson, A Jonckheere, P Jonsson, A Juste, D Käfer, S Kahn, E Kajfasz, AM Kalinin, JM Kalk, JR Kalk, S Kappler, D Karmanov, J Kasper, P Kasper, I Katsanos, D Kau, R Kaur, V Kaushik, R Kehoe, S Kermiche, N Khalatyan, A Khanov, A Kharchilava, YM Kharzheev, D Khatidze, H Kim, TJ Kim, MH Kirby, M Kirsch, B Klima, JM Kohli, J-P Konrath, M Kopal, VM Korablev, B Kothari, AV Kozelov, D Krop, A Kryemadhi, T Kuhl, A Kumar, S Kunori, A Kupco, T Kurca, J Kvita, D Lam, S Lammers, G Landsberg, J Lazoflores, P Lebrun, WM Lee, A Leflat, F Lehner, J Lellouch, V Lesne, J Leveque, P Lewis, J Li, L Li, QZ Li, SM Lietti, JGR Lima, D Lincoln, J Linnemann, VV Lipaev, R Lipton, Y Liu, Z Liu, L Lobo, A Lobodenko, M Lokajicek, A Lounis, P Love, HJ Lubatti, AL Lyon, AKA Maciel, D Mackin, RJ Madaras, P Mättig, C Magass, A Magerkurth, N Makovec, PK Mal, HB Malbouisson, S Malik, VL Malyshev, HS Mao, Y Maravin, B Martin, R McCarthy, A Melnitchouk, A Mendes, L Mendoza, PG Mercadante, M Merkin, KW Merritt, A Meyer, J Meyer, M Michaut, T Millet, J Mitrevski, J Molina, RK Mommsen, NK Mondal, RW Moore, T Moulik, GS Muanza, M Mulders, M Mulhearn, O Mundal, L Mundim, E Nagy, M Naimuddin, M Narain, NA Naumann, HA Neal, JP Negret, P Neustroev, H Nilsen, C Noeding, A Nomerotski, SF Novaes, T Nunnemann, V O'dell, DC O'neil, G Obrant, C Ochando, D Onoprienko, N Oshima, J Osta, R Otec, GJ Otero Y Garzón, M Owen, P Padley, M Pangilinan, N Parashar, S-J Park, SK Park, J Parsons, R Partridge, N Parua, A Patwa, G Pawloski, PM Perea, K Peters, Y Peters, P Pétroff, M Petteni, R Piegaia, J Piper, M-A Pleier, PLM Podesta-Lerma, VM Podstavkov, Y Pogorelov, M-E Pol, A Pompos, BG Pope, AV Popov, C Potter, WL Prado da Silva, HB Prosper, S Protopopescu, J Qian, A Quadt, B Quinn, A Rakitine, MS Rangel, KJ Rani, K Ranjan, PN Ratoff, P Renkel, S Reucroft, P Rich, M Rijssenbeek, I Ripp-Baudot, F Rizatdinova, S Robinson, RF Rodrigues, C Royon, P Rubinov, R Ruchti, G Safronov, G Sajot, A Sánchez-Hernández, MP Sanders, A Santoro, G Savage, L Sawyer, T Scanlon, D Schaile, RD Schamberger, Y Scheglov, H Schellman, P Schieferdecker, T Schliephake, C Schmitt, C Schwanenberger, A Schwartzman, R Schwienhorst, J Sekaric, S Sengupta, H Severini, E Shabalina, M Shamim, V Shary, AA Shchukin, RK Shivpuri, D Shpakov, V Siccardi, V Simak, V Sirotenko, P Skubic, P Slattery, D Smirnov, RP Smith, GR Snow, J Snow, S Snyder, S Söldner-Rembold, L Sonnenschein, A Sopczak, M Sosebee, K Soustruznik, M Souza, B Spurlock, J Stark, J Steele, V Stolin, A Stone, DA Stoyanova, J Strandberg, S Strandberg, MA Strang, M Strauss, R Ströhmer, D Strom, M Strovink, L Stutte, S Sumowidagdo, P Svoisky, A Sznajder, M Talby, P Tamburello, A Tanasijczuk, W Taylor, P Telford, J Temple, B Tiller, F Tissandier, M Titov, VV Tokmenin, M Tomoto, T Toole, I Torchiani, T Trefzger, D Tsybychev, B Tuchming, C Tully, PM Tuts, R Unalan, L Uvarov, S Uvarov, S Uzunyan, B Vachon, PJ van den Berg, B van Eijk, R Van Kooten, WM van Leeuwen, N Varelas, EW Varnes, A Vartapetian, IA Vasilyev, M Vaupel, P Verdier, LS Vertogradov, M Verzocchi, F Villeneuve-Seguier, P Vint, E Von Toerne, M Voutilainen, M Vreeswijk, R Wagner, HD Wahl, L Wang, MHLS Wang, J Warchol, G Watts, M Wayne, G Weber, M Weber, H Weerts, A Wenger, N Wermes, M Wetstein, A White, D Wicke, GW Wilson, SJ Wimpenny, M Wobisch, DR Wood, TR Wyatt, Y Xie, S Yacoob, R Yamada, M Yan, T Yasuda, YA Yatsunenko, K Yip, HD Yoo, SW Youn, C Yu, J Yu, A Yurkewicz, A Zatserklyaniy, C Zeitnitz, D Zhang, T Zhao, B Zhou, J Zhu, M Zielinski, D Zieminska, A Zieminski, L Zivkovic, V Zutshi, EG Zverev, D0 Collaboration

Abstract:

Long-lived, heavy particles are predicted in a number of models beyond the standard model of particle physics. We present the first direct search for such particles' decays, occurring up to 100 h after their production and not synchronized with an accelerator bunch crossing. We apply the analysis to the gluino (g), predicted in split supersymmetry, which after hadronization can become charged and lose enough momentum through ionization to come to rest in dense particle detectors. Approximately 410 pb(-1) of pp collisions at square root(s) = 1.96 TeV collected with the D0 detector during Run II of the Fermilab Tevatron collider are analyzed in search of such "stopped gluinos" decaying into a gluon and a neutralino (chi(1)(0)). Limits are placed on the (gluino cross section) x (probability to stop) x [BR(g --> g chi(1)(0))] as a function of the gluino and chi(1)(0) masses, for gluino lifetimes from 30 micros-100 h.