Quantum-correlated measurements of $D\to K^{0}_{\rm S}\pi^{+}\pi^{-}\pi^{0}$ decays and consequences for the determination of the CKM angle $\gamma$

(2017)

Authors:

Resmi P K, Jim Libby, Sneha Malde, Guy Wilkinson

Measurement of the $B^{\pm}$ production cross-section in pp collisions at $\sqrt{s} =$ 7 and 13 TeV

(2017)

Authors:

LHCb collaboration, R Aaij, B Adeva, M Adinolfi, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, A Alfonso Albero, 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, F Archilli, P d'Argent, J Arnau Romeu, A Artamonov, M Artuso, E Aslanides, M Atzeni, G Auriemma, M Baalouch, I Babuschkin, S Bachmann, JJ Back, A Badalov, C Baesso, S Baker, V Balagura, W Baldini, A Baranov, RJ Barlow, C Barschel, S Barsuk, W Barter, F Baryshnikov, V Batozskaya, V Battista, A Bay, L Beaucourt, J Beddow, F Bedeschi, I Bediaga, A Beiter, LJ Bel, N Beliy, V Bellee, N Belloli, K Belous, I Belyaev, E Ben-Haim, G Bencivenni, S Benson, S Beranek, A Berezhnoy, R Bernet, D Berninghoff, E Bertholet, A Bertolin, C Betancourt, F Betti, M-O Bettler, M van Beuzekom, Ia Bezshyiko, S Bifani, P Billoir, A Birnkraut, A Bizzeti, M Bjørn, T Blake, F Blanc, S Blusk, V Bocci, T Boettcher, A Bondar, N Bondar, I Bordyuzhin, S Borghi, M Borisyak, M Borsato, F Bossu, M Boubdir, TJV Bowcock, E Bowen, C Bozzi, S Braun, T Britton, J Brodzicka, D Brundu, E Buchanan, C Burr, A Bursche, J Buytaert, W Byczynski, S Cadeddu, H Cai, R Calabrese, R Calladine, M Calvi, M Calvo Gomez, A Camboni, P Campana, DH Campora Perez, L Capriotti, A Carbone, G Carboni, R Cardinale, A Cardini, P Carniti, L Carson, K Carvalho Akiba, G Casse, L Cassina, M Cattaneo, G Cavallero, R Cenci, D Chamont, MG Chapman, M Charles, Ph Charpentier, G Chatzikonstantinidis, M Chefdeville, S Chen, SF Cheung, S-G Chitic, V Chobanova, M Chrzaszcz, A Chubykin, P Ciambrone, X Cid Vidal, G Ciezarek, PEL Clarke, M Clemencic, HV Cliff, J Closier, J Cogan, E Cogneras, V Cogoni, L Cojocariu, P Collins, T Colombo, A Comerma-Montells, A Contu, A Cook, G Coombs, S Coquereau, G Corti, M Corvo, CM Costa Sobral, B Couturier, GA Cowan, DC Craik, A Crocombe, M Cruz Torres, R Currie, C D'Ambrosio, F Da Cunha Marinho, E Dall'Occo, J Dalseno, A Davis, O De Aguiar Francisco, S De Capua, M De Cian, JM De Miranda, L De Paula, M De Serio, P De Simone, CT Dean, D Decamp, L Del Buono, H-P Dembinski, M Demmer, A Dendek, D Derkach, O Deschamps, F Dettori, B Dey, A Di Canto, P Di Nezza, H Dijkstra, F Dordei, M Dorigo, A Dosil Suárez, L Douglas, A Dovbnya, K Dreimanis, L Dufour, G Dujany, P Durante, R Dzhelyadin, M Dziewiecki, A Dziurda, A Dzyuba, S Easo, M Ebert, U Egede, V Egorychev, S Eidelman, S Eisenhardt, U Eitschberger, R Ekelhof, L Eklund, S Ely, S Esen, HM Evans, T Evans, A Falabella, N Farley, S Farry, D Fazzini, L Federici, D Ferguson, G Fernandez, P Fernandez Declara, A Fernandez Prieto, F Ferrari, F Ferreira Rodrigues, M Ferro-Luzzi, S Filippov, RA Fini, M Fiorini, M Firlej, C Fitzpatrick, T Fiutowski, F Fleuret, K Fohl, M Fontana, F Fontanelli, DC Forshaw, R Forty, V Franco Lima, M Frank, C Frei, J Fu, W Funk, E Furfaro, C Färber, E Gabriel, A Gallas Torreira, D Galli, S Gallorini, S Gambetta, M Gandelman, P Gandini, Y Gao, LM Garcia Martin, 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, E Govorkova, JP Grabowski, R Graciani Diaz, LA Granado Cardoso, E Graugés, E Graverini, G Graziani, A Grecu, R Greim, P Griffith, L Grillo, L Gruber, BR Gruberg Cazon, O Grünberg, E Gushchin, Yu Guz, T Gys, C Göbel, T Hadavizadeh, C Hadjivasiliou, G Haefeli, C Haen, SC Haines, B Hamilton, X Han, TH Hancock, S Hansmann-Menzemer, N Harnew, ST Harnew, C Hasse, M Hatch, J He, M Hecker, K Heinicke, A Heister, K Hennessy, P Henrard, L Henry, E van Herwijnen, M Heß, A Hicheur, D Hill, C Hombach, PH Hopchev, W Hu, ZC Huard, W Hulsbergen, T Humair, M Hushchyn, D Hutchcroft, P Ibis, M Idzik, P Ilten, R Jacobsson, J Jalocha, E Jans, A Jawahery, F Jiang, M John, D Johnson, CR Jones, C Joram, B Jost, N Jurik, S Kandybei, M Karacson, JM Kariuki, S Karodia, N Kazeev, M Kecke, F Keizer, M Kelsey, M Kenzie, T Ketel, E Khairullin, B Khanji, C Khurewathanakul, T Kirn, S Klaver, K Klimaszewski, T Klimkovich, S Koliiev, M Kolpin, R Kopecna, P Koppenburg, A Kosmyntseva, S Kotriakhova, M Kozeiha, L Kravchuk, M Kreps, F Kress, P Krokovny, F Kruse, W Krzemien, W Kucewicz, M Kucharczyk, V Kudryavtsev, AK Kuonen, T Kvaratskheliya, D Lacarrere, G Lafferty, A Lai, G Lanfranchi, C Langenbruch, T Latham, C Lazzeroni, R Le Gac, A Leflat, J Lefrançois, R Lefèvre, F Lemaitre, E Lemos Cid, O Leroy, T Lesiak, B Leverington, P-R Li, T Li, Y Li, Z Li, T Likhomanenko, R Lindner, F Lionetto, V Lisovskyi, X Liu, D Loh, A Loi, 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, V Macko, P Mackowiak, S Maddrell-Mander, O Maev, K Maguire, D Maisuzenko, MW Majewski, S Malde, B Malecki, A Malinin, T Maltsev, G Manca, G Mancinelli, D Marangotto, J Maratas, JF Marchand, U Marconi, C Marin Benito, M Marinangeli, P Marino, J Marks, G Martellotti, M Martin, M Martinelli, D Martinez Santos, F Martinez Vidal, LM Massacrier, A Massafferri, R Matev, A Mathad, Z Mathe, C Matteuzzi, A Mauri, E Maurice, B Maurin, A Mazurov, M McCann, A McNab, R McNulty, JV Mead, B Meadows, C Meaux, F Meier, N Meinert, D Melnychuk, M Merk, A Merli, E Michielin, DA Milanes, E Millard, M-N Minard, L Minzoni, DS Mitzel, A Mogini, J Molina Rodriguez, T Mombächer, IA Monroy, S Monteil, M Morandin, MJ Morello, O Morgunova, J Moron, AB Morris, R Mountain, F Muheim, M Mulder, 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, TD Nguyen, C Nguyen-Mau, S Nieswand, R Niet, N Nikitin, T Nikodem, A Nogay, DP O'Hanlon, A Oblakowska-Mucha, V Obraztsov, S Ogilvy, R Oldeman, CJG Onderwater, A Ossowska, JM Otalora Goicochea, P Owen, A Oyanguren, PR Pais, A Palano, M Palutan, A Papanestis, M Pappagallo, LL Pappalardo, W Parker, C Parkes, G Passaleva, A Pastore, 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, F Pisani, A Pistone, A Piucci, V Placinta, S Playfer, M Plo Casasus, F Polci, M Poli Lener, A Poluektov, I Polyakov, E Polycarpo, GJ Pomery, S Ponce, A Popov, D Popov, S Poslavskii, C Potterat, E Price, J Prisciandaro, C Prouve, V Pugatch, A Puig Navarro, H Pullen, G Punzi, W Qian, R Quagliani, B Quintana, B Rachwal, JH Rademacker, M Rama, M Ramos Pernas, MS Rangel, I Raniuk, F Ratnikov, G Raven, M Ravonel Salzgeber, M Reboud, 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, A Robert, AB Rodrigues, E Rodrigues, JA Rodriguez Lopez, A Rogozhnikov, S Roiser, A Rollings, V Romanovskiy, A Romero Vidal, JW Ronayne, M Rotondo, MS Rudolph, T Ruf, P Ruiz Valls, J Ruiz Vidal, 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, G Sarpis, A Sarti, C Satriano, A Satta, DM Saunders, D Savrina, S Schael, M Schellenberg, M Schiller, H Schindler, M Schmelling, T Schmelzer, B Schmidt, O Schneider, A Schopper, HF Schreiner, M Schubiger, M-H Schune, R Schwemmer, B Sciascia, A Sciubba, A Semennikov, ES Sepulveda, A Sergi, N Serra, J Serrano, L Sestini, P Seyfert, M Shapkin, I Shapoval, Y Shcheglov, T Shears, L Shekhtman, V Shevchenko, BG Siddi, R Silva Coutinho, L Silva de Oliveira, G Simi, S Simone, M Sirendi, N Skidmore, T Skwarnicki, E Smith, IT Smith, J Smith, M Smith, L Soares Lavra, MD Sokoloff, FJP Soler, B Souza De Paula, B Spaan, P Spradlin, S Sridharan, F Stagni, M Stahl, S Stahl, P Stefko, S Stefkova, O Steinkamp, S Stemmle, O Stenyakin, M Stepanova, H Stevens, S Stone, B Storaci, S Stracka, ME Stramaglia, M Straticiuc, U Straumann, J Sun, L Sun, W Sutcliffe, K Swientek, V Syropoulos, T Szumlak, M Szymanski, S T'Jampens, A Tayduganov, T Tekampe, G Tellarini, F Teubert, E Thomas, J van Tilburg, MJ Tilley, V Tisserand, M Tobin, S Tolk, L Tomassetti, D Tonelli, F Toriello, R Tourinho Jadallah Aoude, E Tournefier, M Traill, MT Tran, M Tresch, A Trisovic, A Tsaregorodtsev, P Tsopelas, A Tully, N Tuning, A Ukleja, A Usachov, A Ustyuzhanin, U Uwer, C Vacca, A Vagner, V Vagnoni, A Valassi, S Valat, G Valenti, R Vazquez Gomez, P Vazquez Regueiro, S Vecchi, M van Veghel, JJ Velthuis, M Veltri, G Veneziano, A Venkateswaran, TA Verlage, M Vernet, M Vesterinen, JV Viana Barbosa, B Viaud, D Vieira, M Vieites Diaz, H Viemann, X Vilasis-Cardona, M Vitti, V Volkov, A Vollhardt, B Voneki, 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, C Weisser, M Whitehead, J Wicht, G Wilkinson, M Wilkinson, M Williams, MP Williams, M Williams, T Williams, FF Wilson, J Wimberley, M Winn, J Wishahi, W Wislicki, M Witek, G Wormser, SA Wotton, K Wraight, K Wyllie, Y Xie, M Xu, Z Xu, Z Yang, Z Yang, Y Yao, H Yin, J Yu, X Yuan, O Yushchenko, KA Zarebski, M Zavertyaev, L Zhang, Y Zhang, A Zhelezov, Y Zheng, X Zhu, V Zhukov, JB Zonneveld, S Zucchelli

Improved limit on the branching fraction of the rare decay $${{K} ^0_{\mathrm { \scriptscriptstyle S}}} \rightarrow \mu ^+\mu ^-$$

European Physical Journal C Springer 77:10 (2017) 678

Authors:

R Aaij, B Adeva, M Adinolfi, Tim Evans, Paolo Gandini, Barak R Gruberg Cazon, Thomas Hadavizadeh, Neville Harnew, Donal Hill, Pawel G Jalocha, Malcolm JJ John, Nathan P Jurik, Sneha Malde, Anita K Nandi, Alexandra Rollings, Stig Topp-Joergensen, Giovanni Veneziano, Guy Wilkinson

Abstract:

A search for the decay $K^0_{\scriptscriptstyle S}\to\mu^+\mu^-$ is performed, based on a data sample of proton-proton collisions corresponding to an integrated luminosity of 3 fb$^{-1}$, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The observed yield is consistent with the background-only hypothesis, yielding a limit on the branching fraction of ${\cal B}(K^0_{\scriptscriptstyle S}\to\mu^+\mu^-) < 0.8~(1.0) \times 10^{-9}$ at $90\%~(95\%)$ confidence level. This result improves the previous upper limit on the branching fraction by an order of magnitude.

Latest results from the TORCH R&D; Project

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Elsevier (2017)

Authors:

T Gys, N Brook, L Castillo García, D Cussans, K Föhl, R Forty, C Frei, Rui Gao, Neville Harnew, D Piedigrossi, J Rademacker, A Ros García, Maarten WU van Dijk

Abstract:

TORCH (Timing Of internally Reflected CHerenkov photons) is a precision time-of-flight detector for particle identification at low momentum. It uses Cherenkov photons produced by charged particles passing through a quartz radiator plate. Some of these photons propagate by total internal reflection, they emerge at the edges and are subsequently focused onto photon detectors. The recorded positions and arrival times of the photons are used to precisely reconstruct their trajectory and propagation time in the quartz. This allows to determine the crossing time of the particles through the plate. The TORCH design requires the development of fast photon detectors with fine and asymmetric anode segmentation. The overall per-photon time precision must be better than 70 ps after signal processing and photon path reconstruction in the quartz. In addition, the photon detectors must survive several years of high illumination levels. The on-going R&D; programme aims at demonstrating the TORCH basic concept through the realization of a detector module equipped with custom photon detectors featuring the required granularity and lifetime, with dedicated fast front-end electronics and with high-quality quartz radiator and focussing optics. This paper will report on the latest TORCH results achieved in the laboratory and in charged particle beam tests. It will also introduce the developments towards a full-scale module prototype.

Observation of D0 meson decays to π+π−μ+μ− and K+K−μ+μ− final states

Physical Review Letters American Physical Society 119:18 (2017) 181805

Authors:

R Aaij, B Adeva, M Adinolfi, Mikkel Bjørn, Thomas Evans, Paolo Gandini, Barak R Gruberg Cazon, Thomas Hadavizadeh, Thomas H Hancock, Neville Harnew, Donal Hill, Pawel G Jalocha, Malcolm JJ John, Nathan P Jurik, Sneha Malde, Anita K Nandi, Hannah L Pullen, Alexandra Rollings, Mika Vesterinen, Guy R Wilkinson

Abstract:

The first observation of the D0→π+π−μ+μ− and D0→K+K−μ+μ− decays is reported using a sample of proton-proton collisions collected by LHCb at a center-of-mass energy of 8 TeV, and corresponding to 2  fb^−1 of integrated luminosity. The corresponding branching fractions are measured using as normalization the decay D0→K−π+[μ+μ−]ρ0/ω, where the two muons are consistent with coming from the decay of a ρ0 or ω meson. The results are B(D0→π+π−μ+μ−)=(9.64±0.48±0.51±0.97)×10^−7 and B(D0→K+K−μ+μ−)=(1.54±0.27±0.09±0.16)×10^−7, where the uncertainties are statistical, systematic, and due to the limited knowledge of the normalization branching fraction. The dependence of the branching fraction on the dimuon mass is also investigated.