Observation of the Λ0b → Λφ decay

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics Elsevier 759 (2016) 282-292

Authors:

Shu-Faye Cheung, Tim Evans, Paolo Gandini, Barak R Gruberg Cadzon, Thomas Hadavizadeh, Neville Harnew, Donal Hill, Pawel G Jalocha, Malcolm John, Oliver J Lupton, Sneha S Malde, Anita K Nandi, Stig Topp-Jorgenson, Guy R Wilkinson

Abstract:

The Λ0b → Λφ decay is observed using data corresponding to an integrated luminosity of 3.0 fb^-1 recorded by the LHCb experiment. The decay proceeds at leading order via a b → sss loop transition and is therefore sensitive to the possible presence of particles beyond the Standard Model. A first observation is reported with a significance of 5.9 standard deviations. The value of the branching fraction is measured to be (5.18 ± 1.04 ± 0.35^+0.67-0.62) X 10^-6, where the first uncertainty is statistical, the second is systematic, and the third is related to external inputs. Triple-product asymmetries are measured to be consistent with zero.

Search for violations of Lorentz invariance and CPT symmetry in Bs^0 mixing.

Physical Review Letters American Physical Society 116:24 (2016) 241601

Authors:

Shu-Faye Cheung, Tim Evans, Paolo Gandini, Thomas Hadavizadeh, Neville Harnew, Donal Hill, Pawel G Jalocha, Malcolm John, Oliver J Lupton, Sneha S Malde, Anita K Nandi, Stig Topp-Jorgenson, Guy R Wilkinson

Abstract:

Violations of CPT symmetry and Lorentz invariance are searched for by studying interference effects in B^0 mixing and in Bs^0 mixing. Samples of B^0 → J/ψKS^0 and Bs^0 → J/ψK^+K^- decays are recorded by the LHCb detector in proton-proton collisions at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb^-1. No periodic variations of the particle-antiparticle mass differences are found, consistent with Lorentz invariance and CPT symmetry. Results are expressed in terms of the standard model extension parameter Δaμ with precisions of O(10^-15) and O(10^-14)  GeV for the B^0 and Bs^0 systems, respectively. With no assumption on Lorentz (non)invariance, the CPT-violating parameter z in the Bs^0 system is measured for the first time and found to be Re(z) = -0.022 ± 0.033 ± 0.005 and Im(z) = 0.004 ± 0.011 ± 0.002, where the first uncertainties are statistical and the second systematic.

TORCH - Cherenkov and Time-of-Flight PID Detector for the LHCb Upgrade at CERN

International Workshop on Fast Cherenkov Detectors - Photon detection, DIRC design and DAQ (DIRC15) Institute of Physics (2016)

Authors:

Neville Harnew, Rui Gao, Klaus Föhl, Nick Brook, Lucia Castillo García, Thomas M Conneely, David Cussans, Roger Forty, Christophe Frei, Thierry Gys, James Milnes, Jonas Rademacker, Didier Piedigrossi, Ana Ros Garcia, Maarten van Dijk

Abstract:

TORCH is a large-area precision time-of-flight detector, based on Cherenkov light production and propagation in a quartz radiator plate, which is read out at its edges. TORCH is proposed for the LHCb experiment at CERN to provide positive particle identification for kaons, and is currently in the Research-and-Development phase. A brief overview of the micro-channel plate photon sensor development, the custom-made electronics, and an introduction to the current test beam activities is given. Optical readout solutions are presented for the potential use of BaBar DIRC bar boxes as part of the TORCH configuration in LHCb.

Observation of Λb0 → ψ(2S)pK− and Λb0 → J/ψπ+π−pK− decays and a measurement of the Λb0 baryon mass

Journal of High Energy Physics Springer Nature 2016:5 (2016) 132

Authors:

The LHCb collaboration, R Aaij, C Abellán Beteta, B Adeva, M Adinolfi, A Affolder, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, S Ali, G Alkhazov, P Alvarez Cartelle, AA Alves, S Amato, S Amerio, Y Amhis, L An, L Anderlini, G Andreassi, M Andreotti, JE Andrews, RB Appleby, O Aquines Gutierrez, F Archilli, P d’Argent, A Artamonov, M Artuso, E Aslanides, G Auriemma, M Baalouch, S Bachmann, JJ Back, A Badalov, C Baesso, W Baldini, RJ Barlow, C Barschel, S Barsuk, W Barter, V Batozskaya, V Battista, A Bay, L Beaucourt, J Beddow, F Bedeschi, I Bediaga, LJ Bel, V Bellee, N Belloli, I Belyaev, E Ben-Haim, G Bencivenni, S Benson, J Benton, A Berezhnoy, R Bernet, A Bertolin, F Betti, M-O Bettler, M van Beuzekom, S Bifani, P Billoir, T Bird, A Birnkraut, A Bizzeti, T Blake, F Blanc, J Blouw, S Blusk, V Bocci, A Bondar, N Bondar, W Bonivento, A Borgheresi, S Borghi, M Borisyak, M Borsato, TJV Bowcock, E Bowen, C Bozzi, S Braun, M Britsch, T Britton, J Brodzicka, NH Brook, E Buchanan, C Burr, A Bursche, J Buytaert, S Cadeddu, R Calabrese, M Calvi, M Calvo Gomez, P Campana, D Campora Perez, L Capriotti, A Carbone, G Carboni, R Cardinale, A Cardini, P Carniti, L Carson, K Carvalho Akiba, G Casse, L Cassina, L Castillo Garcia, M Cattaneo, Ch Cauet, G Cavallero, R Cenci, M Charles, Ph Charpentier, G Chatzikonstantinidis, M Chefdeville, S Chen, S-F Cheung, N Chiapolini, M Chrzaszcz, X Cid Vidal, G Ciezarek, PEL Clarke, M Clemencic, HV Cliff, J Closier, V Coco, J Cogan, E Cogneras, V Cogoni, L Cojocariu, G Collazuol, P Collins, A Comerma-Montells, A Contu, A Cook, M Coombes, S Coquereau, G Corti, M Corvo, B Couturier, GA Cowan, DC Craik, A Crocombe, M Cruz Torres, S Cunliffe, R Currie, C D’Ambrosio, E Dall’Occo, J Dalseno, PNY David, A Davis, O De Aguiar Francisco, K De Bruyn, S De Capua, M De Cian, JM De Miranda, L De Paula, P De Simone, C-T Dean, D Decamp, M Deckenhoff, L Del Buono, N Déléage, M Demmer, D Derkach, O Deschamps, F Dettori, B Dey, A Di Canto, F Di Ruscio, H Dijkstra, S Donleavy, F Dordei, M Dorigo, A Dosil Suárez, A Dovbnya, K Dreimanis, L Dufour, G Dujany, K Dungs, P Durante, R Dzhelyadin, A Dziurda, A Dzyuba, S Easo, U Egede, V Egorychev, S Eidelman, S Eisenhardt, U Eitschberger, R Ekelhof, L Eklund, I El Rifai, Ch Elsasser, S Ely, S Esen, HM Evans, T Evans, A Falabella, C Färber, N Farley, S Farry, R Fay, D Fazzini, D Ferguson, V Fernandez Albor, F Ferrari, F Ferreira Rodrigues, M Ferro-Luzzi, S Filippov, M Fiore, M Fiorini, M Firlej, C Fitzpatrick, T Fiutowski, F Fleuret, K Fohl, M Fontana, F Fontanelli, DC Forshaw, R Forty, M Frank, C Frei, M Frosini, J Fu, E Furfaro, A Gallas Torreira, D Galli, S Gallorini, S Gambetta, M Gandelman, P Gandini, Y Gao, J García Pardiñas, J Garra Tico, L Garrido, D Gascon, C Gaspar, L Gavardi, G Gazzoni, D Gerick, E Gersabeck, M Gersabeck, T Gershon, Ph Ghez, S Gianì, V Gibson, OG Girard, L Giubega, VV Gligorov, C Göbel, D Golubkov, A Golutvin, A Gomes, C Gotti, M Grabalosa Gándara, R Graciani Diaz, LA Granado Cardoso, E Graugés, E Graverini, G Graziani, A Grecu, P Griffith, L Grillo, O Grünberg, B Gui, E Gushchin, Yu Guz, T Gys, T Hadavizadeh, C Hadjivasiliou, G Haefeli, C Haen, SC Haines, S Hall, B Hamilton, X Han, S Hansmann-Menzemer, N Harnew, ST Harnew, J Harrison, J He, T Head, V Heijne, A Heister, K Hennessy, P Henrard, L Henry, JA Hernando Morata, E van Herwijnen, M Heß, A Hicheur, D Hill, M Hoballah, C Hombach, L Hongming, W Hulsbergen, T Humair, M Hushchyn, N Hussain, D Hutchcroft, M Idzik, P Ilten, R Jacobsson, A Jaeger, J Jalocha, E Jans, A Jawahery, M John, D Johnson, CR Jones, C Joram, B Jost, N Jurik, S Kandybei, W Kanso, M Karacson, TM Karbach, S Karodia, M Kecke, M Kelsey, IR Kenyon, M Kenzie, T Ketel, E Khairullin, B Khanji, C Khurewathanakul, T Kirn, S Klaver, K Klimaszewski, O Kochebina, M Kolpin, I Komarov, RF Koopman, P Koppenburg, M Kozeiha, L Kravchuk, K Kreplin, M Kreps, P Krokovny, F Kruse, W Krzemien, W Kucewicz, M Kucharczyk, V Kudryavtsev, AK Kuonen, K Kurek, T Kvaratskheliya, D Lacarrere, G Lafferty, A Lai, D Lambert, G Lanfranchi, C Langenbruch, B Langhans, T Latham, C Lazzeroni, R Le Gac, J van Leerdam, J-P Lees, R Lefèvre, A Leflat, J Lefrançois, E Lemos Cid, O Leroy, T Lesiak, B Leverington, Y Li, T Likhomanenko, M Liles, R Lindner, C Linn, F Lionetto, B Liu, X Liu, D Loh, I Longstaff, JH Lopes, D Lucchesi, M Lucio Martinez, H Luo, A Lupato, E Luppi, O Lupton, N Lusardi, A Lusiani, F Machefert, F Maciuc, O Maev, K Maguire, S Malde, A Malinin, G Manca, G Mancinelli, P Manning, A Mapelli, J Maratas, JF Marchand, U Marconi, C Marin Benito, P Marino, J Marks, G Martellotti, M Martin, M Martinelli, D Martinez Santos, F Martinez Vidal, D Martins Tostes, LM Massacrier, A Massafferri, R Matev, A Mathad, Z Mathe, C Matteuzzi, A Mauri, B Maurin, A Mazurov, M McCann, J McCarthy, A McNab, R McNulty, B Meadows, F Meier, M Meissner, D Melnychuk, M Merk, A Merli, E Michielin, DA Milanes, M-N Minard, DS Mitzel, J Molina Rodriguez, IA Monroy, S Monteil, M Morandin, P Morawski, A Mordà, MJ Morello, J Moron, AB Morris, R Mountain, F Muheim, D Müller, J Müller, K Müller, V Müller, M Mussini, B Muster, P Naik, T Nakada, R Nandakumar, A Nandi, I Nasteva, M Needham, N Neri, S Neubert, N Neufeld, M Neuner, AD Nguyen, C Nguyen-Mau, V Niess, S Nieswand, R Niet, N Nikitin, T Nikodem, A Novoselov, DP O’Hanlon, A Oblakowska-Mucha, V Obraztsov, S Ogilvy, O Okhrimenko, R Oldeman, CJG Onderwater, B Osorio Rodrigues, JM Otalora Goicochea, A Otto, P Owen, A Oyanguren, A Palano, F Palombo, M Palutan, J Panman, A Papanestis, M Pappagallo, LL Pappalardo, C Pappenheimer, W Parker, C Parkes, G Passaleva, GD Patel, M Patel, C Patrignani, A Pearce, A Pellegrino, G Penso, M Pepe Altarelli, S Perazzini, P Perret, L Pescatore, K Petridis, A Petrolini, M Petruzzo, E Picatoste Olloqui, B Pietrzyk, M Pikies, D Pinci, A Pistone, A Piucci, S Playfer, M Plo Casasus, T Poikela, F Polci, A Poluektov, I Polyakov, E Polycarpo, A Popov, D Popov, B Popovici, C Potterat, E Price, JD Price, J Prisciandaro, A Pritchard, C Prouve, V Pugatch, A Puig Navarro, G Punzi, W Qian, R Quagliani, B Rachwal, JH Rademacker, M Rama, M Ramos Pernas, MS Rangel, I Raniuk, G Raven, F Redi, S Reichert, AC dos Reis, V Renaudin, S Ricciardi, S Richards, M Rihl, K Rinnert, V Rives Molina, P Robbe, AB Rodrigues, E Rodrigues, JA Rodriguez Lopez, P Rodriguez Perez, A Rogozhnikov, S Roiser, V Romanovsky, A Romero Vidal, JW Ronayne, M Rotondo, T Ruf, P Ruiz Valls, JJ Saborido Silva, N Sagidova, B Saitta, V Salustino Guimaraes, C Sanchez Mayordomo, B Sanmartin Sedes, R Santacesaria, C Santamarina Rios, M Santimaria, E Santovetti, A Sarti, C Satriano, A Satta, DM Saunders, D Savrina, S Schael, M Schiller, H Schindler, M Schlupp, M Schmelling, T Schmelzer, B Schmidt, O Schneider, A Schopper, M Schubiger, M-H Schune, R Schwemmer, B Sciascia, A Sciubba, A Semennikov, A Sergi, N Serra, J Serrano, L Sestini, P Seyfert, M Shapkin, I Shapoval, Y Shcheglov, T Shears, L Shekhtman, V Shevchenko, A Shires, BG Siddi, R Silva Coutinho, L Silva de Oliveira, G Simi, M Sirendi, N Skidmore, T Skwarnicki, E Smith, IT Smith, J Smith, M Smith, H Snoek, MD Sokoloff, FJP Soler, F Soomro, D Souza, B Souza De Paula, B Spaan, P Spradlin, S Sridharan, F Stagni, M Stahl, S Stahl, S Stefkova, O Steinkamp, O Stenyakin, S Stevenson, S Stoica, S Stone, B Storaci, S Stracka, M Straticiuc, U Straumann, L Sun, W Sutcliffe, K Swientek, S Swientek, V Syropoulos, M Szczekowski, T Szumlak, S T’Jampens, A Tayduganov, T Tekampe, G Tellarini, F Teubert, C Thomas, E Thomas, J van Tilburg, V Tisserand, M Tobin, J Todd, S Tolk, L Tomassetti, D Tonelli, S Topp-Joergensen, E Tournefier, S Tourneur, K Trabelsi, M Traill, MT Tran, M Tresch, A Trisovic, A Tsaregorodtsev, P Tsopelas, N Tuning, A Ukleja, A Ustyuzhanin, U Uwer, C Vacca, V Vagnoni, G Valenti, A Vallier, R Vazquez Gomez, P Vazquez Regueiro, C Vázquez Sierra, S Vecchi, M van Veghel, JJ Velthuis, M Veltri, G Veneziano, M Vesterinen, B Viaud, D Vieira, M Vieites Diaz, X Vilasis-Cardona, V Volkov, A Vollhardt, D Voong, A Vorobyev, V Vorobyev, C Voß, JA de Vries, R Waldi, C Wallace, R Wallace, J Walsh, J Wang, DR Ward, NK Watson, D Websdale, A Weiden, M Whitehead, J Wicht, G Wilkinson, M Wilkinson, M Williams, MP Williams, M Williams, T Williams, FF Wilson, J Wimberley, J Wishahi, W Wislicki, M Witek, G Wormser, SA Wotton, K Wraight, S Wright, K Wyllie, Y Xie, Z Xu, Z Yang, H Yin, J Yu, X Yuan, O Yushchenko, M Zangoli, M Zavertyaev, L Zhang, Y Zhang, A Zhelezov, Y Zheng, A Zhokhov, L Zhong, V Zhukov, S Zucchelli

Observation of B_{s}^{0}→D[over ¯]^{0}K_{S}^{0} and Evidence for B_{s}^{0}→D[over ¯]^{*}^{0}K_{S}^{0} Decays.

Physical Review Letters American Physical Society 116:16 (2016) 161802

Authors:

S-F Cheung, T Evans, P Gandini, R Gauld, E Greening, T Hadavizadeh, N Harnew, D Hill, N Hussain, J Jalocha, M John, O Lupton, S Malde, A Nandi, E Smith, S Stevenson, C Thomas, S Topp-Joergensen, N Torr, G Wilkinson

Abstract:

The first observation of the B_{s}^{0}→D[over ¯]^{0}K_{S}^{0} decay mode and evidence for the B_{s}^{0}→D[over ¯]^{*0}K_{S}^{0} decay mode are reported. The data sample corresponds to an integrated luminosity of 3.0  fb^{-1} collected in pp collisions by LHCb at center-of-mass energies of 7 and 8 TeV. The branching fractions are measured to be B(B_{s}^{0}→D[over ¯]^{0}K[over ¯]^{0})=[4.3±0.5(stat)±0.3(syst)±0.3(frag)±0.6(norm)]×10^{-4},B(B_{s}^{0}→D[over ¯]^{*0}K[over ¯]^{0})=[2.8±1.0(stat)±0.3(syst)±0.2(frag)±0.4(norm)]×10^{-4},where the uncertainties are due to contributions coming from statistical precision, systematic effects, and the precision of two external inputs, the ratio f_{s}/f_{d} and the branching fraction of B^{0}→D[over ¯]^{0}K_{S}^{0}, which is used as a calibration channel.