Observation of the narrow state X(3872) → J/ψπ+π- in p̄p collisions at √s = 1.96 TeV

Physical Review Letters 93:7 (2004)

Authors:

D Acosta, T Affolder, MH Ahn, T Akimoto, MG Albrow, D Ambrose, S Amerio, D Amidei, A Anastassov, K Anikeev, A Annovi, J Antos, M Aoki, G Apollinari, JF Arguin, T Arisawa, A Artikov, T Asakawa, W Ashmanskas, A Attal, F Azfar, P Azzi-Bacchetta, N Bacchetta, H Bachacou, W Badgett, S Bailey, A Barbaro-Galtieri, G Barker, VE Barnes, BA Barnett, S Baroiant, M Barone, G Bauer, F Bedeschi, S Behari, S Belforte, WH Bell, G Bellettini, J Bellinger, D Benjamin, A Beretvas, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, A Bocci, A Bodek, G Bolla, A Bolshov, PSL Booth, D Bortoletto, J Boudreau, S Bourov, C Bromberg, E Brubaker, J Budagov, HS Budd, K Burkett, G Busetto, P Bussey, KL Byrum, S Cabrera, P Calafiura, M Campanelli, M Campbell, A Canepa, D Carlsmith, S Carron, R Carosi, M Casarsa, A Castro, P Catastini, D Cauz, A Cerri, C Cerri, L Cerrito, J Chapman, C Chen, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, K Cho, D Chokheli, ML Chu, JY Chung, WH Chung, YS Chung, CI Ciobanu, MA Ciocci, AG Clark, D Clark, MN Coca, A Connolly, ME Convery

Abstract:

The observation of a state consistent with X(3872) decaying into J/ψπ+π- was reported. The X(3872) mass was measured to be 3871.3±0.7(stat)±0.4(syst)MeV/c2 from a sample of 730±90 candidates. The observed width was consistent with the detector resolution. The results were found to be converging well with the measurements by the Belle Collaboration using b± decays.

Performance of Hamamatsu 64-anode photomultipliers for use with wavelength--shifting optical fibres

ArXiv physics/0408055 (2004)

Authors:

N Tagg, A De Santo, A Weber, A Cabrera, PS Miyagawa, MA Barker, K Lang, D Michael, R Saakyan, J Thomas

Search for Bs0 → μ+μ - and Bd0 → μ+μ - decays in pp̄ collisions at √s = 1.96 TeV

Physical Review Letters 93:3 (2004)

Authors:

D Acousta, T Affolder, T Akimoto, MG Albrow, D Ambrose, S Amerio, D Amidei, A Anastassov, K Anikeev, A Annovi, J Antos, M Aoki, G Apollinari, T Arisawa, JF Arguin, A Artikov, W Ashmanskas, A Attal, F Azfar, P Azzi-Bacchetta, N Bacchetta, H Bachacou, W Badgett, A Barbaro-Galtieri, GJ Barker, VE Barnes, BA Barnett, S Baroiant, M Barone, G Bauer, F Bedeschi, S Behari, S Belforte, G Bellettini, J Bellinger, D Benjamin, A Beretvas, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, A Bocci, A Bodek, G Bolla, A Bolshov, PSL Booth, D Bortoletto, J Boudreau, S Bourov, C Bromberg, E Brubaker, J Budagov, HS Budd, K Burkett, G Busetto, P Bussey, KL Byrum, S Cabrera, P Calafiura, M Campanelli, M Campbell, A Canepa, M Casarsa, D Carlsmith, S Carron, R Carosi, A Castro, P Catastini, D Cauz, A Cerri, C Cerri, L Cerrito, J Chapman, C Chen, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, I Cho, K Cho, D Chokheli, ML Chu, S Chuang, JY Chung, WH Chung, YS Chung, CI Ciobanu, MA Ciocci, AG Clark, D Clark, M Coca, A Connolly, M Convery, J Conway, M Cordelli

Abstract:

The decay mechanisms of Bs0 → μ +μ- and Bd0 → μ +μ- in pp̄ collisions were investigated. For discrimination of the decays from background events, four variables were used such as invariant mass of muon pair, B-candidate proper decay length, opening angle between B-hadron flight direction and B-candidate track isolation. A 'blind' analysis technique was also used for determination of optimal selection criteria for four variables. The results show that optimal set of selection criteria uses ∓80 MeV/c2 search window around B s0 mass, and I > 0.65.

Search for narrow tt̄ Resonances in pp̄ collisions at √s = 1.8 Te V

Physical Review Letters 92:22 (2004)

Authors:

VM Abazov, B Abbott, A Abdesselam, M Abolins, V Abramov, BS Acharya, DL Adams, M Adams, SN Ahmed, GD Alexeev, A Alton, GA Alves, EW Anderson, Y Arnoud, C Avila, VV Babintsev, L Babukhadia, TC Bacon, A Baden, S Baffioni, B Baldin, PW Balm, S Banerjee, E Barberis, P Baringer, J Barreto, JF Bartlett, U Bassler, D Bauer, A Bean, F Beaudette, M Begel, A Belyaev, SB Beri, G Bernardi, I Bertram, A Besson, R Beuselinck, VA Bezzubov, PC Bhat, V Bhatnagar, M Bhattacharjee, G Blazey, F Blekman, S Blessing, A Boehnlein, NI Bojko, TA Bolton, F Borcherding, K Bos, T Bose, A Brandt, G Briskin, R Brock, G Brooijmans, A Bross, D Buchholz, M Buehler, V Buescher, VS Burtovoi, JM Butler, F Canelli, W Carvalho, D Casey, H Castilla-Valdez, D Chakraborty, KM Chan, SV Chekulaev, DK Cho, S Choi, S Chopra, D Claes, AR Clark, B Connolly, WE Cooper, D Coppage, S Crépé-Renaudin, MAC Cummings, D Cutts, H da Motta, GA Davis, K De, SJ de Jong, M Demarteau, R Demina, P Demine, D Denisov, SP Denisov, S Desai, HT Diehl, M Diesburg, S Doulas, LV Dudko, S Duensing, L Duflot, SR Dugad, A Duperrin, A Dyshkant, D Edmunds, J Ellison

Abstract:

A search for narrow resonances decaying to tt̄ pairs was carried out. No significant deviation was observed from the standard-model predictions at a top-quark mass of 175 GeV/c2. Upper limits were established at the 95% confidence level on the product of the production cross section and branching fraction to tt̄ for narrow resonances as a function of the resonance mass Mx. The existence of a leptophobic top-color particle with mass Mx<560 GeV/c2 was excluded for a width T x = 0.012Mx.

Search for pair production of light scalar top quarks in pp collisions at √s = 1.8 TeV

Physical Review Letters 93:1 (2004)

Authors:

VM Abazov, B Abbott, A Abdesselam, M Abolins, V Abramov, BS Acharya, DL Adams, M Adams, SN Ahmed, GD Alexeev, A Alton, GA Alves, Y Arnoud, C Avila, VV Babintsev, L Babukhadia, TC Bacon, A Baden, S Baffioni, B Baldin, PW Balm, S Banerjee, E Barberis, P Baringer, J Barreto, JF Bartlett, U Bassler, D Bauer, A Bean, F Beaudette, M Begel, A Belyaev, SB Beri, G Bernardi, I Bertram, A Besson, R Beuselinck, VA Bezzubov, PC Bhat, V Bhatnagar, M Bhattacharjee, G Blazey, F Blekman, S Blessing, A Boehnlein, NI Bojko, TA Bolton, F Borcherding, K Bos, T Bose, A Brandt, G Briskin, R Brock, G Brooijmans, A Bross, D Buchholz, M Buehler, V Buescher, VS Burtovoi, JM Butler, F Canelli, W Carvalho, D Casey, H Castilla-Valdez, D Chakraborty, KM Chan, SV Chekulaev, DK Cho, S Choi, S Chopra, D Claes, AR Clark, B Connolly, WE Cooper, D Coppage, S Crépé-Renaudin, MAC Cummings, D Cutts, H da Motta, GA Davis, K De, SJ de Jong, M Demarteau, R Demina, P Demine, D Denisov, SP Denisov, S Desai, HT Diehl, M Diesburg, S Doulas, LV Dudko, L Duflot, SR Dugad, A Duperrin, A Dyshkant, D Edmunds, J Ellison, JT Eltzroth, VD Elvira

Abstract:

The results of a search for direct pair production of scalar top quarks (t̃), the supersymmetric partners of the top quark were presented. Events containing two or more jets and missing transverse energy, the signature of light scalar top quark decays to charm quarks and neutralinos were investigated. 27 events were observed after the selection, while expecting 31.1±6.4 events from known standard model processes. The results were compared to next-to-leading-order production cross sections, and a significant region of t̃ and neutralino phase space was excluded.