CP-violation in partially reconstructed B± → D*h± decays at LHCb

Abstract:

This thesis presents a measurement of CP-violation in partially reconstructed B±→D*K± and B±→D*π± decays, where the neutral pion and photon from the D*→Dπ0 and D*→Dγ decays are not reconstructed. The D meson is subsequently reconstructed in the D→KS0π+π− or D→KS0K+K− final state. The measurement of CP-violation is performed by analysing the distribution of the signal yields over the D-decay phase space, without relying on a D-decay amplitude model. Instead, inputs for strong phase-related parameters measured at CLEO and BESIII are used. The measurement is performed using proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7, 8, and 13 TeV, with a total integrated luminosity of approximately 9 fb−1. The work in this thesis measures CP-violating observables using partially reconstructed B±→D*K± and B±→D*π± decays at LHCb. These observables are interpreted in terms of physical parameters, including the Cabibbo-Kobayashi-Maskawa angle, γ, a fundamental Standard Model parameter. This is found to be γ = (92 +21 -17)◦, where the total uncertainty includes the statistical and all systematic uncertainties.

Measurement of CP observables in B-->DK*+ decays using two and four body D final states

Journal of High Energy Physics Institute of Physics Publishing

Authors:

Sneha Malde, G wilkinson, Neville Harnew, M John, M Vesterinen

Model-independent measurement of the CKM angle $γ$ using $B^0 \to D K^{\ast 0}$ decays with $D \to K_{S}^{0} π^{+} π^{-}$ and $K_{S}^{0} K^{+} K^{-}$

JHEP 06 131-131

Authors:

R Aaij, CA Beteta, B Adeva, M Adinolfi, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, S Ali, G Alkhazov, PA Cartelle, AAA Jr, S Amato, S Amerio, Y Amhis, L An, L Anderlini, G Andreassi, M Andreotti, JE Andrews, RB Appleby, OA Gutierrez, F Archilli, P d'Argent, A Artamonov, M Artuso, E Aslanides, G Auriemma, M Baalouch, S Bachmann, JJ Back, A Badalov, C Baesso, S Baker, 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, MV 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, 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, MC Gomez, P Campana, DC Perez, L Capriotti, A Carbone, G Carboni, R Cardinale, A Cardini, P Carniti, L Carson, KC Akiba, G Casse, L Cassina, LC Garcia, M Cattaneo, C Cauet, G Cavallero, R Cenci, M Charles, P Charpentier, G Chatzikonstantinidis, M Chefdeville, S Chen, S-F Cheung, V Chobanova, M Chrzaszcz, XC 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, B Couturier, GA Cowan, DC Craik, A Crocombe, MC Torres, S Cunliffe, R Currie, C D'Ambrosio, E Dall'Occo, J Dalseno, PNY David, A Davis, ODA Francisco, KD Bruyn, SD Capua, MD Cian, JMD Miranda, LD Paula, PD Simone, C-T Dean, D Decamp, M Deckenhoff, LD Buono, N Déléage, M Demmer, D Derkach, O Deschamps, F Dettori, B Dey, AD Canto, H Dijkstra, F Dordei, M Dorigo, AD 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, IE Rifai, C Elsasser, S Ely, S Esen, HM Evans, T Evans, A Falabella, C Färber, N Farley, S Farry, R Fay, D Fazzini, D Ferguson, VF Albor, F Ferrari, FF 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, AG Torreira, D Galli, S Gallorini, S Gambetta, M Gandelman, P Gandini, Y Gao, JG Pardiñas, JG Tico, L Garrido, PJ Garsed, D Gascon, C Gaspar, L Gavardi, G Gazzoni, D Gerick, E Gersabeck, M Gersabeck, T Gershon, P Ghez, S Gianì, V Gibson, OG Girard, L Giubega, VV Gligorov, C Göbel, D Golubkov, A Golutvin, A Gomes, C Gotti, MG Gándara, RG Diaz, LAG Cardoso, E Graugés, E Graverini, G Graziani, A Grecu, P Griffith, L Grillo, O Grünberg, E Gushchin, Y 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, A Heister, K Hennessy, P Henrard, L Henry, JAH Morata, EV 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, 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, RL Gac, JV Leerdam, J-P Lees, R Lefèvre, A Leflat, J Lefrançois, EL 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, ML Martinez, H Luo, A Lupato, E Luppi, O Lupton, N Lusardi, A Lusiani, X Lyu, 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, CM Benito, P Marino, J Marks, G Martellotti, M Martin, M Martinelli, DM Santos, FM Vidal, DM 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, JM 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, BO Rodrigues, JMO 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, MP Altarelli, S Perazzini, P Perret, L Pescatore, K Petridis, A Petrolini, M Petruzzo, EP Olloqui, B Pietrzyk, M Pikies, D Pinci, A Pistone, A Piucci, S Playfer, MP 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, AP Navarro, G Punzi, W Qian, R Quagliani, B Rachwal, JH Rademacker, M Rama, MR Pernas, MS Rangel, I Raniuk, G Raven, F Redi, S Reichert, ACD Reis, V Renaudin, S Ricciardi, S Richards, M Rihl, K Rinnert, VR Molina, P Robbe, AB Rodrigues, E Rodrigues, JAR Lopez, PR Perez, A Rogozhnikov, S Roiser, V Romanovsky, AR Vidal, JW Ronayne, M Rotondo, T Ruf, PR Valls, JJS Silva, N Sagidova, B Saitta, VS Guimaraes, CS Mayordomo, BS Sedes, R Santacesaria, CS 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, RS Coutinho, LSD 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, BSD 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, JV Tilburg, V Tisserand, M Tobin, 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, S Valat, G Valenti, A Vallier, RV Gomez, PV Regueiro, CV Sierra, S Vecchi, MV Veghel, JJ Velthuis, M Veltri, G Veneziano, M Vesterinen, B Viaud, D Vieira, MV Diaz, X Vilasis-Cardona, V Volkov, A Vollhardt, D Voong, A Vorobyev, V Vorobyev, C Voß, JAD 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

Abstract:

A binned Dalitz plot analysis of the decays $B^0 \to D K^{\ast 0}$, with $D \to K_{S}^{0} \pi^{+} \pi^{-}$ and $K_{S}^{0} K^{+} K^{-}$, is performed to measure the observables $x_\pm$ and $y_\pm$, which are related to the CKM angle $\gamma$ 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 $3.0\,\rm{fb}^{-1}$, collected by the LHCb experiment, the values of the $CP$ violation parameters are found to be $x_+ = 0.05 \pm 0.35 \pm 0.02$, $x_-=-0.31\pm 0.20 \pm 0.04$, $y_+=-0.81\pm 0.28\pm 0.06$ and $y_-=0.31\pm 0.21 \pm 0.05$, where the first uncertainties are statistical and the second systematic. These observables correspond to values $\gamma$ = $(71 \pm 20)^\circ$, $r_{B^0} = 0.56\pm 0.17$ and $\delta_{B^0} = (204\,^{+21}_{-20})^\circ$. The parameters $r_{B^0}$ and $\delta_{B^0}$ 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 $\pm 50$ MeV/$c^2$ around the $K^{\ast}(892)^{0}$ mass and with the magnitude of the cosine of the $K^{\ast}(892)^{0}$ helicity angle larger than 0.4.

Observation of an exotic narrow doubly charmed tetraquark

Particle Identification at LHCb

Proceedings of Science

Abstract:

Particle identification (PID) is a fundamental requirement for LHCb and is provided by CALO, Muon and RICH sub-detectors. The Calorimeters provide identification of electrons, photons and hadrons in addition to the measurement of their energies and positions. As well as being part of the LHCb trigger, the Muon system provides identification of muons to a very high level of purity, essential for many CP-sensitive measurements that have J=y’s in their final states. Hadron identification, in particular the ability to distinguish kaons and pions, is crucial to many LHCb analyses, particularly where the final states of interest are purely hadronic. The LHCb RICH system provides this, covering a momentum range between approximately 1 and 100 GeV/c. To maintain the integrity of the LHCb physics performance, it is essential to measure and monitor the particle identification efficiency and misidentification fraction over time. This can be done by using specific decays, such as of the K0S , phi, Lambda and J/psi, for which pure samples can be isolated using only kinematic quantities, due to their unique decay topologies. This allows for clean samples of known particle types to be selected, which can then be used to calibrate and monitor the PID performance from data. The procedures for performing this will be presented, together with preliminary results from the 2010 LHC run.