Constraints on the unitarity triangle angle from Dalitz plot analysis of B0 → DK+π− decays

Physical Review D American Physical Society 93:11 (2016) 112018

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:

The first study is presented of CP violation with an amplitude analysis of the Dalitz plot of B0 → DK+π- decays, with D→K+π-, K+K-, and π+π-. The analysis is based on a data sample corresponding to 3.0 fb-1 of pp collisions collected with the LHCb detector. No significant CP violation effect is seen, and constraints are placed on the angle γ of the unitarity triangle formed from elements of the Cabibbo-Kobayashi-Maskawa quark mixing matrix. Hadronic parameters associated with the B0→DK∗(892)0 decay are determined for the first time. These measurements can be used to improve the sensitivity to γ of existing and future studies of the B0 → DK∗(892)0 decay.

Core subjects

Economist (United Kingdom) 412:8991 (2016)

Authors:

W Anne, M John

Evidence for exotic hadron contributions to $\Lambda_b^0 \to J/\psi p \pi^-$ decays

(2016)

Authors:

LHCb collaboration, R Aaij, C Abellán Beteta, B Adeva, M Adinolfi, 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, J Arnau Romeu, 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, K Belous, I Belyaev, E Ben-Haim, G Bencivenni, S Benson, J Benton, A Berezhnoy, R Bernet, A Bertolin, M-O Bettler, M van Beuzekom, S Bifani, P Billoir, T Bird, A Birnkraut, A Bitadze, A Bizzeti, T Blake, F Blanc, J Blouw, S Blusk, V Bocci, T Boettcher, A Bondar, N Bondar, W Bonivento, S Borghi, M Borisyak, M Borsato, F Bossu, M Boubdir, TJV Bowcock, E Bowen, C Bozzi, S Braun, M Britsch, T Britton, J Brodzicka, 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, V Chobanova, 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, S Coquereau, G Corti, M Corvo, CM Costa Sobral, 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, M Demmer, D Derkach, O Deschamps, F Dettori, B Dey, A Di Canto, H Dijkstra, 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, N Déléage, S Easo, U Egede, V Egorychev, S Eidelman, S Eisenhardt, U Eitschberger, R Ekelhof, L Eklund, Ch Elsasser, S Ely, S Esen, HM Evans, T Evans, A Falabella, N Farley, S Farry, R Fay, 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, C Färber, A Gallas Torreira, D Galli, S Gallorini, S Gambetta, M Gandelman, P Gandini, Y Gao, J García Pardiñas, J Garra Tico, L Garrido, PJ Garsed, 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, K Gizdov, VV Gligorov, D Golubkov, A Golutvin, A Gomes, IV Gorelov, C Gotti, M Grabalosa Gándara, R Graciani Diaz, LA Granado Cardoso, E Graugés, E Graverini, G Graziani, A Grecu, P Griffith, L Grillo, BR Gruberg Cazon, O Grünberg, E Gushchin, Yu Guz, T Gys, C Göbel, 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, A Heister, K Hennessy, P Henrard, L Henry, JA Hernando Morata, E van Herwijnen, M Heß, A Hicheur, D Hill, C Hombach, 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, JM Kariuki, S Karodia, M Kecke, M Kelsey, IR Kenyon, M Kenzie, T Ketel, E Khairullin, B Khanji, C Khurewathanakul, T Kirn, S Klaver, K Klimaszewski, S Koliiev, M Kolpin, I Komarov, RF Koopman, P Koppenburg, A Kozachuk, 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, A Leflat, J Lefrançois, R Lefèvre, F Lemaitre, E Lemos Cid, O Leroy, T Lesiak, B Leverington, Y Li, T Likhomanenko, 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, A Lusiani, X Lyu, F Machefert, F Maciuc, O Maev, K Maguire, S Malde, A Malinin, T Maltsev, G Manca, G Mancinelli, P Manning, 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, 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, M Mulder, M Mussini, D Müller, J Müller, K Müller, V Müller, 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, JM Otalora Goicochea, A Otto, P Owen, A Oyanguren, PR Pais, 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, A Petrov, 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, GJ Pomery, 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, C Remon Alepuz, 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 Romanovskiy, A Romero Vidal, JW Ronayne, M Rotondo, T Ruf, P Ruiz Valls, JJ Saborido Silva, E Sadykhov, 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, D Souza, B Souza De Paula, B Spaan, P Spradlin, S Sridharan, F Stagni, M Stahl, S Stahl, P Stefko, 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, 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, S Tolk, L Tomassetti, D Tonelli, S Topp-Joergensen, F Toriello, E Tournefier, S Tourneur, K Trabelsi, M Traill, MT Tran, M Tresch, A Trisovic, A Tsaregorodtsev, P Tsopelas, A Tully, N Tuning, A Ukleja, A Ustyuzhanin, U Uwer, C Vacca, V Vagnoni, S Valat, G Valenti, A Vallier, R Vazquez Gomez, P Vazquez Regueiro, S Vecchi, M van Veghel, JJ Velthuis, M Veltri, G Veneziano, A Venkateswaran, M Vesterinen, B Viaud, D Vieira, M Vieites Diaz, X Vilasis-Cardona, V Volkov, A Vollhardt, B Voneki, D Voong, A Vorobyev, V Vorobyev, C Voß, JA de Vries, C Vázquez Sierra, R Waldi, C Wallace, R Wallace, J Walsh, J Wang, DR Ward, HM Wark, 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, KA Zarebski, M Zavertyaev, L Zhang, Y Zhang, Y Zhang, A Zhelezov, Y Zheng, A Zhokhov, V Zhukov, S Zucchelli

Model-independent measurement of the CKM angle γ using B0 → DK∗0 decays with D → K 0 S π + π − and K 0 S K+K−

Journal of High Energy Physics Springer 2016:6 (2016) 131

Authors:

LHCb Collaboration, R Aaij, C Abellán Beteta, B Adeva, Sneha Malde, Shu-Faye Cheung, Tim Evans, Paolo Gandini, Thomas Hadavizadeh, Neville Harnew, Malcolm John, Oliver J Lupton, Anita K Nandi, Wenbin Qian, Stigg Topp-Joergensen, Guy Wilkinson

Abstract:

A binned Dalitz plot analysis of the decays B 0 → DK ∗0, with D → K 0 S π + π − and D → K 0 S K + K −, is performed to measure the observables x ± and y ±, which are related to the CKM angle γ and the hadronic parameters of the decays. The D decay strong phase variation over the Dalitz plot is taken from measurements performed at the CLEO-c experiment, making the analysis independent of the D decay model. With a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb−1, collected by the LHCb experiment, the values of the CP violation parameters are found to be x + = 0.05 ± 0.35 ± 0.02, x − = −0.31 ± 0.20 ± 0.04, y + = −0.81 ± 0.28 ± 0.06 and y − = 0.31 ± 0.21 ± 0.05, where the first uncertainties are statistical and the second systematic. These observables correspond to values γ = (71 ± 20)°, and . The parameters and are the magnitude ratio and strong phase difference between the suppressed and favoured B 0 decay amplitudes, and have been measured in a region of ±50 MeV/c 2 around the K ∗(892)0 mass and with the magnitude of the cosine of the K ∗(892)0 helicity angle larger than 0.4.

Test-beam and laboratory characterisation of the TORCH prototype detector

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Elsevier 845 (2016) 452-458

Authors:

Ana Ros, Nick H Brook, Lucia Castillo-Garcia, Tom Conneely, David Cussans, Klaus Foehl, Roger Forty, Christophe Frei, Rui Gao, Thierry Gys, Neville Harnew, James Milnes, Didier Piedigrossi, Jonas Rademacker, Maarten Van Dijk

Abstract:

The TORCH time-of-flight (TOF) detector is being developed to provide particle identification up to a momentum of 10 GeV/c over a flight distance of 10 m. It has a DIRC-like construction with thick synthetic amorphous fused-silica plates as a Cherenkov radiator. Photons propagate by total internal reflection to the plate periphery where they are focused onto an array of customised position-sensitive micro-channel plate (MCP) detectors. The goal is to achieve a 15 ps time-of-flight resolution per incident particle by combining arrival times from multiple photons. The MCPs have pixels of effective size 0.4 mm×6.6 mm2 in the vertical and horizontal directions, respectively, by incorporating a novel charge-sharing technique to improve the spatial resolution to better than the pitch of the readout anodes. Prototype photon detectors and readout electronics have been tested and calibrated in the laboratory. Preliminary results from testbeam measurements of a prototype TORCH detector are also presented.