Precision measurement of the Lambda_b baryon lifetime

ArXiv 1307.2476 (2013)

Authors:

LHCb collaboration, R Aaij, B Adeva, M Adinolfi, C Adrover, A Affolder, Z Ajaltouni, J Albrecht, F Alessio, M Alexander, S Ali, G Alkhazov, P Alvarez Cartelle, AA Alves Jr, S Amato, S Amerio, Y Amhis, L Anderlini, J Anderson, R Andreassen, JE Andrews, RB Appleby, O Aquines Gutierrez, F Archilli, A Artamonov, M Artuso, E Aslanides, G Auriemma, M Baalouch, S Bachmann, JJ Back, C Baesso, V Balagura, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, Th Bauer, A Bay, J Beddow, F Bedeschi, I Bediaga, S Belogurov, K Belous, I Belyaev, E Ben-Haim, G Bencivenni, S Benson, J Benton, A Berezhnoy, R Bernet, M-O Bettler, M van Beuzekom, A Bien, S Bifani, T Bird, A Bizzeti, PM Bjørnstad, T Blake, F Blanc, J Blouw, S Blusk, V Bocci, A Bondar, N Bondar, W Bonivento, S Borghi, A Borgia, TJV Bowcock, E Bowen, C Bozzi, T Brambach, J van den Brand, J Bressieux, D Brett, M Britsch, T Britton, NH Brook, H Brown, I Burducea, A Bursche, G Busetto, J Buytaert, S Cadeddu, O Callot, M Calvi, M Calvo Gomez, A Camboni, P Campana, D Campora Perez, A Carbone, G Carboni, R Cardinale, A Cardini, H Carranza-Mejia, L Carson, K Carvalho Akiba, G Casse, L Castillo Garcia, M Cattaneo, Ch Cauet, R Cenci, M Charles, Ph Charpentier, P Chen, N Chiapolini, M Chrzaszcz, K Ciba, X Cid Vidal, G Ciezarek, PEL Clarke, M Clemencic, HV Cliff, J Closier, C Coca, V Coco, J Cogan, E Cogneras, P Collins, A Comerma-Montells, A Contu, A Cook, M Coombes, S Coquereau, G Corti, B Couturier, GA Cowan, DC Craik, S Cunliffe, R Currie, C D'Ambrosio, P David, PNY David, A Davis, I De Bonis, K De Bruyn, S De Capua, M De Cian, JM De Miranda, L De Paula, W De Silva, P De Simone, D Decamp, M Deckenhoff, L Del Buono, N Déléage, D Derkach, O Deschamps, F Dettori, A Di Canto, H Dijkstra, M Dogaru, S Donleavy, F Dordei, A Dosil Suárez, D Dossett, A Dovbnya, F Dupertuis, P Durante, R Dzhelyadin, A Dziurda, A Dzyuba, S Easo, U Egede, V Egorychev, S Eidelman, D van Eijk, S Eisenhardt, U Eitschberger, R Ekelhof, L Eklund, I El Rifai, Ch Elsasser, A Falabella, C Färber, G Fardell, C Farinelli, S Farry, D Ferguson, V Fernandez Albor, F Ferreira Rodrigues, M Ferro-Luzzi, S Filippov, M Fiore, C Fitzpatrick, M Fontana, F Fontanelli, R Forty, O Francisco, M Frank, C Frei, M Frosini, S Furcas, E Furfaro, A Gallas Torreira, D Galli, M Gandelman, P Gandini, Y Gao, J Garofoli, P Garosi, J Garra Tico, L Garrido, C Gaspar, R Gauld, E Gersabeck, M Gersabeck, T Gershon, Ph Ghez, V Gibson, L Giubega, VV Gligorov, C Göbel, D Golubkov, A Golutvin, A Gomes, P Gorbounov, H Gordon, M Grabalosa Gándara, R Graciani Diaz, LA Granado Cardoso, E Graugés, G Graziani, A Grecu, E Greening, S Gregson, P Griffith, O Grünberg, B Gui, E Gushchin, Yu Guz, T Gys, C Hadjivasiliou, G Haefeli, C Haen, SC Haines, S Hall, B Hamilton, T Hampson, S Hansmann-Menzemer, N Harnew, ST Harnew, J Harrison, T Hartmann, J He, T Head, V Heijne, K Hennessy, P Henrard, JA Hernando Morata, E van Herwijnen, A Hicheur, E Hicks, D Hill, M Hoballah, C Hombach, P Hopchev, W Hulsbergen, P Hunt, T Huse, N Hussain, D Hutchcroft, D Hynds, V Iakovenko, M Idzik, P Ilten, R Jacobsson, A Jaeger, E Jans, P Jaton, A Jawahery, F Jing, M John, D Johnson, CR Jones, C Joram, B Jost, M Kaballo, S Kandybei, W Kanso, M Karacson, TM Karbach, IR Kenyon, T Ketel, A Keune, B Khanji, O Kochebina, I Komarov, RF Koopman, P Koppenburg, M Korolev, A Kozlinskiy, L Kravchuk, K Kreplin, M Kreps, G Krocker, P Krokovny, F Kruse, M Kucharczyk, V Kudryavtsev, T Kvaratskheliya, VN La Thi, D Lacarrere, G Lafferty, A Lai, D Lambert, RW Lambert, E Lanciotti, G Lanfranchi, C Langenbruch, T Latham, C Lazzeroni, R Le Gac, J van Leerdam, J-P Lees, R Lefèvre, A Leflat, J Lefrançois, S Leo, O Leroy, T Lesiak, B Leverington, Y Li, L Li Gioi, M Liles, R Lindner, C Linn, B Liu, G Liu, S Lohn, I Longstaff, JH Lopes, N Lopez-March, H Lu, D Lucchesi, J Luisier, H Luo, F Machefert, IV Machikhiliyan, F Maciuc, O Maev, S Malde, G Manca, G Mancinelli, J Maratas, U Marconi, P Marino, R Märki, J Marks, G Martellotti, A Martens, A Martín Sánchez, M Martinelli, D Martinez Santos, D Martins Tostes, A Massafferri, R Matev, Z Mathe, C Matteuzzi, E Maurice, A Mazurov, B Mc Skelly, J McCarthy, A McNab, R McNulty, B Meadows, F Meier, M Meissner, M Merk, DA Milanes, M-N Minard, J Molina Rodriguez, S Monteil, D Moran, P Morawski, A Mordà, MJ Morello, R Mountain, I Mous, F Muheim, K Müller, R Muresan, B Muryn, B Muster, P Naik, T Nakada, R Nandakumar, I Nasteva, M Needham, S Neubert, N Neufeld, AD Nguyen, TD Nguyen, C Nguyen-Mau, M Nicol, V Niess, R Niet, N Nikitin, T Nikodem, A Nomerotski, A Novoselov, A Oblakowska-Mucha, V Obraztsov, S Oggero, S Ogilvy, O Okhrimenko, R Oldeman, M Orlandea, JM Otalora Goicochea, P Owen, A Oyanguren, BK Pal, A Palano, T Palczewski, M Palutan, J Panman, A Papanestis, M Pappagallo, C Parkes, CJ Parkinson, G Passaleva, GD Patel, M Patel, GN Patrick, C Patrignani, C Pavel-Nicorescu, A Pazos Alvarez, A Pellegrino, G Penso, M Pepe Altarelli, S Perazzini, E Perez Trigo, A Pérez-Calero Yzquierdo, P Perret, M Perrin-Terrin, L Pescatore, E Pesen, G Pessina, K Petridis, A Petrolini, A Phan, E Picatoste Olloqui, B Pietrzyk, T Pilař, D Pinci, S Playfer, M Plo Casasus, F Polci, G Polok, A Poluektov, E Polycarpo, A Popov, D Popov, B Popovici, C Potterat, A Powell, J Prisciandaro, A Pritchard, C Prouve, V Pugatch, A Puig Navarro, G Punzi, W Qian, JH Rademacker, B Rakotomiaramanana, MS Rangel, I Raniuk, N Rauschmayr, G Raven, S Redford, MM Reid, AC dos Reis, S Ricciardi, A Richards, K Rinnert, V Rives Molina, DA Roa Romero, P Robbe, DA Roberts, E Rodrigues, P Rodriguez Perez, S Roiser, V Romanovsky, A Romero Vidal, J Rouvinet, T Ruf, F Ruffini, H Ruiz, P Ruiz Valls, G Sabatino, JJ Saborido Silva, N Sagidova, P Sail, B Saitta, V Salustino Guimaraes, B Sanmartin Sedes, M Sannino, R Santacesaria, C Santamarina Rios, E Santovetti, M Sapunov, A Sarti, C Satriano, A Satta, M Savrie, D Savrina, P Schaack, M Schiller, H Schindler, M Schlupp, M Schmelling, B Schmidt, O Schneider, A Schopper, M-H Schune, R Schwemmer, B Sciascia, A Sciubba, M Seco, A Semennikov, K Senderowska, I Sepp, N Serra, J Serrano, P Seyfert, M Shapkin, I Shapoval, P Shatalov, Y Shcheglov, T Shears, L Shekhtman, O Shevchenko, V Shevchenko, A Shires, R Silva Coutinho, M Sirendi, T Skwarnicki, NA Smith, E Smith, J Smith, M Smith, MD Sokoloff, FJP Soler, F Soomro, D Souza, B Souza De Paula, B Spaan, A Sparkes, P Spradlin, F Stagni, S Stahl, O Steinkamp, S Stevenson, S Stoica, S Stone, B Storaci, M Straticiuc, U Straumann, VK Subbiah, L Sun, S Swientek, V Syropoulos, M Szczekowski, P Szczypka, T Szumlak, S T'Jampens, M Teklishyn, E Teodorescu, F Teubert, C Thomas, E Thomas, J van Tilburg, V Tisserand, M Tobin, S Tolk, D Tonelli, S Topp-Joergensen, N Torr, E Tournefier, S Tourneur, MT Tran, M Tresch, A Tsaregorodtsev, P Tsopelas, N Tuning, M Ubeda Garcia, A Ukleja, D Urner, A Ustyuzhanin, U Uwer, V Vagnoni, G Valenti, A Vallier, M Van Dijk, R Vazquez Gomez, P Vazquez Regueiro, C Vázquez Sierra, S Vecchi, JJ Velthuis, M Veltri, G Veneziano, M Vesterinen, B Viaud, D Vieira, X Vilasis-Cardona, A Vollhardt, D Volyanskyy, D Voong, A Vorobyev, V Vorobyev, C Voß, H Voss, R Waldi, C Wallace, R Wallace, S Wandernoth, J Wang, DR Ward, NK Watson, AD Webber, D Websdale, M Whitehead, J Wicht, J Wiechczynski, D Wiedner, L Wiggers, G Wilkinson, MP Williams, M Williams, FF Wilson, J Wimberley, J Wishahi, W Wislicki, M Witek, SA Wotton, S Wright, S Wu, K Wyllie, Y Xie, Z Xing, Z Yang, R Young, X Yuan, O Yushchenko, M Zangoli, M Zavertyaev, F Zhang, L Zhang, WC Zhang, Y Zhang, A Zhelezov, A Zhokhov, L Zhong, A Zvyagin

Abstract:

The ratio of the \Lambda b baryon lifetime to that of the B0 meson is measured using 1.0/fb of integrated luminosity in 7 TeV center-of-mass energy pp collisions at the LHC. The \Lambda b baryon is observed for the first time in the decay mode \Lambda b -> J/\psi pK-, while the B0 meson decay used is the well known B0 -> J/\psi pi+K- mode, where the pi+ K- mass is consistent with that of the K*0(892) meson. The ratio of lifetimes is measured to be 0.976 +/- 0.012 +/- 0.006, in agreement with theoretical expectations based on the heavy quark expansion. Using previous determinations of the B0 meson lifetime, the \Lambda b lifetime is found to be 1.482 +/- 0.018 +/- 0.012 ps. In both cases the first uncertainty is statistical and the second systematic.

Water as a contrast medium: a re-evaluation using the multidetector-row computed tomography.

Am Surg 79:7 (2013) 728-733

Authors:

Tafadzwa P Makarawo, Edsa Negussie, Sachit Malde, Jacqueline Tilak, Jennifer Gayagoy, Jenna Watson, Faiz Francis, Denis Lincoln, Michael J Jacobs

Abstract:

Water as an intraluminal negative contrast medium produces improved image quality with reduced artefact. However, rapid absorption of oral water in the bowel relative to speed and timing of image capturing has limited its clinical application. These findings predate advances in multidetector-row computed tomography (CT). To re-evaluate differences in image quality, we studied image clarity and luminal distention between the same group of patients who received both a pancreas protocol CT (PPCT) that uses oral water and a conventional positive oral contrast scan. We reviewed 66 patients who had previously undergone both a PPCT and an oral contrast abdominal CT. CT images were independently reviewed by two board-certified radiologists who scored degree of hollow viscus distention and visualization of mural detail using a Likert 5-point scale. Results were evaluated by using the Wilcoxon-signed rank test. Student's t test was applied to evaluate the differences in radiation dosage and Spearman's correlational test was used to evaluate interrater correlation between the radiologists. In comparing the mean radiation dosage, there was no statistical difference between the two protocols, and there was good interrater association with ratios of 0.595 and 0.51 achieved for the PPCT and conventional oral scan, respectively. The Wilcoxon signed-rank test showed statistical differences in the stomach (P < 0.001) for both clarity (P < 0.001) and distention (P < 0.001), the duodenum for both clarity (P < 0.001) and distention (P = 0.02), and the ileum for distention (P = 0.02) with the PPCT having a better median score for organ clarity in the stomach and duodenum and better luminal distention in the stomach, equal distention in the duodenum, and slightly worse distention in the ileum. For the remainder of the bowel and organs evaluated, there was no statistically significant difference in the ratings between the two protocols. Using present CT scan technology, water can be an effective contrast medium causing better or equal distention in the bowel and better or equal clarity than routine barium contrast. This calls for a need to reconsider the use of water as a contrast medium in clinical practice.

First observation of the decay $B_{c}^{+}\to J/\psi K^+$

(2013)

Authors:

LHCb collaboration, R Aaij, C Abellan Beteta, B Adeva, M Adinolfi, C Adrover, A Affolder, Z Ajaltouni, J Albrecht, F Alessio, M Alexander, S Ali, G Alkhazov, P Alvarez Cartelle, AA Alves, S Amato, S Amerio, Y Amhis, L Anderlini, J Anderson, R Andreassen, RB Appleby, O Aquines Gutierrez, F Archilli, A Artamonov, M Artuso, E Aslanides, G Auriemma, S Bachmann, JJ Back, C Baesso, V Balagura, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, Th Bauer, A Bay, J Beddow, F Bedeschi, I Bediaga, S Belogurov, K Belous, I Belyaev, E Ben-Haim, G Bencivenni, S Benson, J Benton, A Berezhnoy, R Bernet, M-O Bettler, M van Beuzekom, A Bien, S Bifani, T Bird, A Bizzeti, PM Bjørnstad, T Blake, F Blanc, J Blouw, S Blusk, V Bocci, A Bondar, N Bondar, W Bonivento, S Borghi, A Borgia, TJV Bowcock, E Bowen, C Bozzi, T Brambach, J van den Brand, J Bressieux, D Brett, M Britsch, T Britton, NH Brook, H Brown, I Burducea, A Bursche, G Busetto, J Buytaert, S Cadeddu, O Callot, M Calvi, M Calvo Gomez, A Camboni, P Campana, D Campora Perez, A Carbone, G Carboni, R Cardinale, A Cardini, H Carranza-Mejia, L Carson, K Carvalho Akiba, G Casse, L Castillo Garcia, M Cattaneo, Ch Cauet, M Charles, Ph Charpentier, P Chen, N Chiapolini, M Chrzaszcz, K Ciba, X Cid Vidal, G Ciezarek, PEL Clarke, M Clemencic, HV Cliff, J Closier, C Coca, V Coco, J Cogan, E Cogneras, P Collins, A Comerma-Montells, A Contu, A Cook, M Coombes, S Coquereau, G Corti, B Couturier, GA Cowan, DC Craik, S Cunliffe, R Currie, C D'Ambrosio, P David, PNY David, A Davis, I De Bonis, K De Bruyn, S De Capua, M De Cian, JM De Miranda, L De Paula, W De Silva, P De Simone, D Decamp, M Deckenhoff, L Del Buono, N Déléage, D Derkach, O Deschamps, F Dettori, A Di Canto, H Dijkstra, M Dogaru, S Donleavy, F Dordei, A Dosil Suárez, D Dossett, A Dovbnya, F Dupertuis, R Dzhelyadin, A Dziurda, A Dzyuba, S Easo, U Egede, V Egorychev, S Eidelman, D van Eijk, S Eisenhardt, U Eitschberger, R Ekelhof, L Eklund, I El Rifai, Ch Elsasser, D Elsby, A Falabella, C Färber, G Fardell, C Farinelli, S Farry, V Fave, D Ferguson, V Fernandez Albor, F Ferreira Rodrigues, M Ferro-Luzzi, S Filippov, M Fiore, C Fitzpatrick, M Fontana, F Fontanelli, R Forty, O Francisco, M Frank, C Frei, M Frosini, S Furcas, E Furfaro, A Gallas Torreira, D Galli, M Gandelman, P Gandini, Y Gao, J Garofoli, P Garosi, J Garra Tico, L Garrido, C Gaspar, R Gauld, E Gersabeck, M Gersabeck, T Gershon, Ph Ghez, V Gibson, VV Gligorov, C Göbel, D Golubkov, A Golutvin, A Gomes, H Gordon, M Grabalosa Gándara, R Graciani Diaz, LA Granado Cardoso, E Graugés, G Graziani, A Grecu, E Greening, S Gregson, P Griffith, O Grünberg, B Gui, E Gushchin, Yu Guz, T Gys, C Hadjivasiliou, G Haefeli, C Haen, SC Haines, S Hall, T Hampson, S Hansmann-Menzemer, N Harnew, ST Harnew, J Harrison, T Hartmann, J He, V Heijne, K Hennessy, P Henrard, JA Hernando Morata, E van Herwijnen, A Hicheur, E Hicks, D Hill, M Hoballah, C Hombach, P Hopchev, W Hulsbergen, P Hunt, T Huse, N Hussain, D Hutchcroft, D Hynds, V Iakovenko, M Idzik, P Ilten, R Jacobsson, A Jaeger, E Jans, P Jaton, A Jawahery, F Jing, M John, D Johnson, CR Jones, C Joram, B Jost, M Kaballo, S Kandybei, M Karacson, TM Karbach, IR Kenyon, U Kerzel, T Ketel, A Keune, B Khanji, O Kochebina, I Komarov, RF Koopman, P Koppenburg, M Korolev, A Kozlinskiy, L Kravchuk, K Kreplin, M Kreps, G Krocker, P Krokovny, F Kruse, M Kucharczyk, V Kudryavtsev, T Kvaratskheliya, VN La Thi, D Lacarrere, G Lafferty, A Lai, D Lambert, RW Lambert, E Lanciotti, G Lanfranchi, C Langenbruch, T Latham, C Lazzeroni, R Le Gac, J van Leerdam, J-P Lees, R Lefèvre, A Leflat, J Lefrançois, S Leo, O Leroy, T Lesiak, B Leverington, Y Li, L Li Gioi, M Liles, R Lindner, C Linn, B Liu, G Liu, S Lohn, I Longstaff, JH Lopes, E Lopez Asamar, N Lopez-March, H Lu, D Lucchesi, J Luisier, H Luo, F Machefert, IV Machikhiliyan, F Maciuc, O Maev, S Malde, G Manca, G Mancinelli, U Marconi, R Märki, J Marks, G Martellotti, A Martens, A Martín Sánchez, M Martinelli, D Martinez Santos, D Martins Tostes, A Massafferri, R Matev, Z Mathe, C Matteuzzi, E Maurice, A Mazurov, B Mc Skelly, J McCarthy, A McNab, R McNulty, B Meadows, F Meier, M Meissner, M Merk, DA Milanes, M-N Minard, J Molina Rodriguez, S Monteil, D Moran, P Morawski, MJ Morello, R Mountain, I Mous, F Muheim, K Müller, R Muresan, B Muryn, B Muster, P Naik, T Nakada, R Nandakumar, I Nasteva, M Needham, N Neufeld, AD Nguyen, TD Nguyen, C Nguyen-Mau, M Nicol, V Niess, R Niet, N Nikitin, T Nikodem, A Nomerotski, A Novoselov, A Oblakowska-Mucha, V Obraztsov, S Oggero, S Ogilvy, O Okhrimenko, R Oldeman, M Orlandea, JM Otalora Goicochea, P Owen, A Oyanguren, BK Pal, A Palano, M Palutan, J Panman, A Papanestis, M Pappagallo, C Parkes, CJ Parkinson, G Passaleva, GD Patel, M Patel, GN Patrick, C Patrignani, C Pavel-Nicorescu, A Pazos Alvarez, A Pellegrino, G Penso, M Pepe Altarelli, S Perazzini, DL Perego, E Perez Trigo, A Pérez-Calero Yzquierdo, P Perret, M Perrin-Terrin, G Pessina, K Petridis, A Petrolini, A Phan, E Picatoste Olloqui, B Pietrzyk, T Pilař, D Pinci, S Playfer, M Plo Casasus, F Polci, G Polok, A Poluektov, E Polycarpo, A Popov, D Popov, B Popovici, C Potterat, A Powell, J Prisciandaro, A Pritchard, C Prouve, V Pugatch, A Puig Navarro, G Punzi, W Qian, JH Rademacker, B Rakotomiaramanana, MS Rangel, I Raniuk, N Rauschmayr, G Raven, S Redford, MM Reid, AC dos Reis, S Ricciardi, A Richards, K Rinnert, V Rives Molina, DA Roa Romero, P Robbe, E Rodrigues, P Rodriguez Perez, S Roiser, V Romanovsky, A Romero Vidal, J Rouvinet, T Ruf, F Ruffini, H Ruiz, P Ruiz Valls, G Sabatino, JJ Saborido Silva, N Sagidova, P Sail, B Saitta, V Salustino Guimaraes, C Salzmann, B Sanmartin Sedes, M Sannino, R Santacesaria, C Santamarina Rios, E Santovetti, M Sapunov, A Sarti, C Satriano, A Satta, M Savrie, D Savrina, P Schaack, M Schiller, H Schindler, M Schlupp, M Schmelling, B Schmidt, O Schneider, A Schopper, M-H Schune, R Schwemmer, B Sciascia, A Sciubba, M Seco, A Semennikov, K Senderowska, I Sepp, N Serra, J Serrano, P Seyfert, M Shapkin, I Shapoval, P Shatalov, Y Shcheglov, T Shears, L Shekhtman, O Shevchenko, V Shevchenko, A Shires, R Silva Coutinho, T Skwarnicki, NA Smith, E Smith, M Smith, MD Sokoloff, FJP Soler, F Soomro, D Souza, B Souza De Paula, B Spaan, A Sparkes, P Spradlin, F Stagni, S Stahl, O Steinkamp, S Stoica, S Stone, B Storaci, M Straticiuc, U Straumann, VK Subbiah, L Sun, S Swientek, V Syropoulos, M Szczekowski, P Szczypka, T Szumlak, S T'Jampens, M Teklishyn, E Teodorescu, F Teubert, C Thomas, E Thomas, J van Tilburg, V Tisserand, M Tobin, S Tolk, D Tonelli, S Topp-Joergensen, N Torr, E Tournefier, S Tourneur, MT Tran, M Tresch, A Tsaregorodtsev, P Tsopelas, N Tuning, M Ubeda Garcia, A Ukleja, D Urner, U Uwer, V Vagnoni, G Valenti, R Vazquez Gomez, P Vazquez Regueiro, S Vecchi, JJ Velthuis, M Veltri, G Veneziano, M Vesterinen, B Viaud, D Vieira, X Vilasis-Cardona, A Vollhardt, D Volyanskyy, D Voong, A Vorobyev, V Vorobyev, C Voß, H Voss, R Waldi, R Wallace, S Wandernoth, J Wang, DR Ward, NK Watson, AD Webber, D Websdale, M Whitehead, J Wicht, J Wiechczynski, D Wiedner, L Wiggers, G Wilkinson, MP Williams, M Williams, FF Wilson, J Wishahi, M Witek, SA Wotton, S Wright, S Wu, K Wyllie, Y Xie, Z Xing, Z Yang, R Young, X Yuan, O Yushchenko, M Zangoli, M Zavertyaev, F Zhang, L Zhang, WC Zhang, Y Zhang, A Zhelezov, A Zhokhov, L Zhong, A Zvyagin

Observation of Bc+→J/ψDs+ and Bc+→J/ψDs*+ decays

Physical Review D - Particles, Fields, Gravitation and Cosmology 87:11 (2013)

Authors:

R Aaij, C Abellan Beteta, B Adeva, M Adinolfi, C Adrover, A Affolder, Z Ajaltouni, J Albrecht, F Alessio, M Alexander, S Ali, G Alkhazov, P Alvarez Cartelle, AA Alves, S Amato, S Amerio, Y Amhis, L Anderlini, J Anderson, R Andreassen, RB Appleby, O Aquines Gutierrez, F Archilli, A Artamonov, M Artuso, E Aslanides, G Auriemma, S Bachmann, JJ Back, C Baesso, V Balagura, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, T Bauer, A Bay, J Beddow, F Bedeschi, I Bediaga, S Belogurov, K Belous, I Belyaev, E Ben-Haim, M Benayoun, G Bencivenni, S Benson, J Benton, A Berezhnoy, R Bernet, MO Bettler, M Van Beuzekom, A Bien, S Bifani, T Bird, A Bizzeti, PM Bjørnstad, T Blake, F Blanc, J Blouw, S Blusk, V Bocci, A Bondar, N Bondar, W Bonivento, S Borghi, A Borgia, TJV Bowcock, E Bowen, C Bozzi, T Brambach, J Van Den Brand, J Bressieux, D Brett, M Britsch, T Britton, NH Brook, H Brown, I Burducea, A Bursche, G Busetto, J Buytaert, S Cadeddu, O Callot, M Calvi, M Calvo Gomez, A Camboni, P Campana, D Campora Perez, A Carbone, G Carboni, R Cardinale, A Cardini, H Carranza-Mejia, L Carson, K Carvalho Akiba, G Casse, M Cattaneo, C Cauet

Abstract:

The decays Bc+→J/ψDs+ and Bc+→J/ψDs*+ are observed for the first time using a dataset, corresponding to an integrated luminosity of 3 fb-1, collected by the LHCb experiment in proton-proton collisions at center-of-mass energies of √s=7 and 8 TeV. The statistical significance for both signals is in excess of 9 standard deviations. The following ratios of branching fractions are measured to be B(Bc+→J/ ψDs+)B(Bc+→J/ψπ+)=2.90±0.57±0.24, B(Bc+→J/ψDs*+)B(Bc+→J/ψDs+)=2.37±0.56±0. 10, where the first uncertainties are statistical and the second systematic. The mass of the Bc+ meson is measured to be mBc+=6276.28±1. 44(stat)±0.36(syst) MeV/c2, using the Bc+→J/ψDs+ decay mode. © 2013 CERN.

Improved Measurement of Absolute Hadronic Branching Fractions of the Ds+ Meson

ArXiv 1306.5363 (2013)

Authors:

CLEO Collaboration, PUE Onyisi, G Bonvicini, D Cinabro, MJ Smith, P Zhou, P Naik, J Rademacker, KW Edwards, RA Briere, H Vogel, JL Rosner, JP Alexander, DG Cassel, S Das, R Ehrlich, L Gibbons, SW Gray, DL Hartill, BK Heltsley, DL Kreinick, VE Kuznetsov, JR Patterson, D Peterson, D Riley, A Ryd, AJ Sadoff, X Shi, WM Sun, J Yelton, P Rubin, N Lowrey, S Mehrabyan, M Selen, J Wiss, J Libby, M Kornicer, RE Mitchell, D Besson, TK Pedlar, D Cronin-Hennessy, J Hietala, S Dobbs, Z Metreveli, KK Seth, A Tomaradze, T Xiao, A Powell, C Thomas, G Wilkinson, DM Asner, G Tatishvili, JY Ge, DH Miller, IPJ Shipsey, B Xin, GS Adams, J Napolitano, KM Ecklund, J Insler, H Muramatsu, LJ Pearson, EH Thorndike, M Artuso, S Blusk, R Mountain, T Skwarnicki, S Stone, JC Wang, LM Zhang

Abstract:

The branching fractions of Ds meson decays serve to normalize many measurements of processes involving charm quarks. Using 586 pb^-1 of e+ e- collisions recorded at a center of mass energy of 4.17 GeV, we determine absolute branching fractions for 13 Ds decays in 16 reconstructed final states with a double tag technique. In particular we make a precise measurement of the branching fraction B(Ds -> K- K+ pi+) = (5.55 +- 0.14 +- 0.13)%, where the uncertainties are statistical and systematic respectively. We find a significantly reduced value of B(Ds -> pi+ pi0 eta') compared to the world average, and our results bring the inclusively and exclusively measured values of B(Ds -> eta' X)$ into agreement. We also search for CP-violating asymmetries in Ds decays and measure the cross-section of e+ e- -> Ds* Ds at Ecm = 4.17 GeV.