Measurement of the relative $B^{-} \!\rightarrow D^{0} / D^{*0} / D^{**0} μ^{-} \overlineν_μ$ branching fractions using $B^{-}$ mesons from $\overline{B}{}_{s2}^{*0}$ decays
LHCb collaboration R. Aaij B. Adeva M. Adinolfi C. A. Aidala Z. Ajaltouni S. Akar P. Albicocco J. Albrecht F. Alessio M. Alexander A. Alfonso Albero S. Ali G. Alkhazov P. Alvarez Cartelle A. A. Alves Jr S. Amato S. Amerio Y. Amhis L. An L. Anderlini G. Andreassi M. Andreotti J. E. Andrews R. B. Appleby F. Archilli P. d'Argent J. Arnau Romeu A. Artamonov M. Artuso K. Arzymatov E. Aslanides M. Atzeni B. Audurier S. Bachmann J. J. Back S. Baker V. Balagura W. Baldini A. Baranov R. J. Barlow S. Barsuk W. Barter F. Baryshnikov V. Batozskaya B. Batsukh V. Battista A. Bay J. Beddow F. Bedeschi I. Bediaga A. Beiter L. J. Bel S. Belin 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. Bhasin J. Bhom S. Bifani P. Billoir A. Birnkraut A. Bizzeti M. Bjørn M. P. Blago T. Blake F. Blanc S. Blusk D. Bobulska V. Bocci O. Boente Garcia T. Boettcher A. Bondar N. Bondar S. Borghi M. Borisyak M. Borsato F. Bossu M. Boubdir T. J. V. Bowcock C. Bozzi S. Braun M. Brodski J. Brodzicka A. Brossa Gonzalo D. Brundu E. Buchanan A. Buonaura 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 D. H. 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 M. G. Chapman M. Charles Ph. Charpentier G. Chatzikonstantinidis M. Chefdeville V. Chekalina C. Chen S. Chen S. -G. Chitic V. Chobanova M. Chrzaszcz A. Chubykin P. Ciambrone X. Cid Vidal G. Ciezarek P. E. L. Clarke M. Clemencic H. V. Cliff J. Closier V. Coco J. A. B. Coelho J. Cogan E. Cogneras L. Cojocariu P. Collins T. Colombo A. Comerma-Montells A. Contu G. Coombs S. Coquereau G. Corti M. Corvo C. M. Costa Sobral B. Couturier G. A. Cowan D. C. Craik A. Crocombe M. Cruz Torres R. Currie C. D'Ambrosio F. Da Cunha Marinho C. L. Da Silva E. Dall'Occo J. Dalseno A. Danilina A. Davis O. De Aguiar Francisco K. De Bruyn S. De Capua M. De Cian J. M. De Miranda L. De Paula M. De Serio P. De Simone C. T. Dean D. Decamp L. Del Buono B. Delaney H. -P. Dembinski M. Demmer A. Dendek D. Derkach O. Deschamps F. Desse F. Dettori B. Dey A. Di Canto P. Di Nezza S. Didenko H. Dijkstra F. Dordei M. Dorigo A. Dosil Suárez L. Douglas A. Dovbnya K. Dreimanis L. Dufour G. Dujany P. Durante J. M. Durham D. Dutta R. Dzhelyadin M. Dziewiecki A. Dziurda A. Dzyuba S. Easo U. Egede V. Egorychev S. Eidelman S. Eisenhardt U. Eitschberger R. Ekelhof L. Eklund S. Ely A. Ene S. Escher S. Esen T. Evans A. Falabella N. Farley S. Farry D. Fazzini L. Federici P. Fernandez Declara A. Fernandez Prieto F. Ferrari L. Ferreira Lopes F. Ferreira Rodrigues M. Ferro-Luzzi S. Filippov R. A. Fini M. Fiorini M. Firlej C. Fitzpatrick T. Fiutowski F. Fleuret M. Fontana F. Fontanelli R. Forty V. Franco Lima M. Frank C. Frei J. Fu W. Funk C. Färber M. Féo Pereira Rivello Carvalho E. Gabriel A. Gallas Torreira D. Galli S. Gallorini S. Gambetta Y. Gan M. Gandelman P. Gandini Y. Gao L. M. Garcia Martin B. Garcia Plana J. García Pardiñas J. Garra Tico L. Garrido D. Gascon C. Gaspar L. Gavardi G. Gazzoni D. Gerick E. Gersabeck M. Gersabeck T. Gershon D. Gerstel Ph. Ghez S. Gianì V. Gibson O. G. Girard L. Giubega K. Gizdov V. V. Gligorov D. Golubkov A. Golutvin A. Gomes I. V. Gorelov C. Gotti E. Govorkova J. P. Grabowski R. Graciani Diaz L. A. Granado Cardoso E. Graugés E. Graverini G. Graziani A. Grecu R. Greim P. Griffith L. Grillo L. Gruber B. R. Gruberg Cazon O. Grünberg C. Gu E. Gushchin Yu. Guz T. Gys C. Göbel T. Hadavizadeh C. Hadjivasiliou G. Haefeli C. Haen S. C. Haines B. Hamilton X. Han T. H. Hancock S. Hansmann-Menzemer N. Harnew S. T. Harnew T. Harrison C. Hasse M. Hatch J. He M. Hecker K. Heinicke A. Heister K. Hennessy L. Henry E. van Herwijnen M. Heß A. Hicheur R. Hidalgo Charman D. Hill M. Hilton P. H. Hopchev W. Hu W. Huang Z. C. Huard W. Hulsbergen T. Humair M. Hushchyn D. Hutchcroft D. Hynds P. Ibis M. Idzik P. Ilten K. Ivshin R. Jacobsson J. Jalocha E. Jans A. Jawahery F. Jiang M. John D. Johnson C. R. Jones C. Joram B. Jost N. Jurik S. Kandybei M. Karacson J. M. Kariuki S. Karodia N. Kazeev M. Kecke F. Keizer M. Kelsey M. Kenzie T. Ketel E. Khairullin B. Khanji C. Khurewathanakul K. E. Kim T. Kirn S. Klaver K. Klimaszewski T. Klimkovich S. Koliiev M. Kolpin R. Kopecna P. Koppenburg I. Kostiuk S. Kotriakhova M. Kozeiha L. Kravchuk M. Kreps F. Kress P. Krokovny W. Krupa W. Krzemien W. Kucewicz M. Kucharczyk V. Kudryavtsev A. K. Kuonen T. Kvaratskheliya D. Lacarrere G. Lafferty A. Lai D. Lancierini G. Lanfranchi C. Langenbruch T. Latham C. Lazzeroni R. Le Gac A. Leflat J. Lefrançois R. Lefèvre F. Lemaitre O. Leroy T. Lesiak B. Leverington P. -R. Li T. Li Z. Li X. Liang T. Likhomanenko R. Lindner F. Lionetto V. Lisovskyi X. Liu D. Loh A. Loi I. Longstaff J. H. Lopes G. H. Lovell D. Lucchesi M. Lucio Martinez 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 M. W. Majewski S. Malde B. Malecki A. Malinin T. Maltsev G. Manca G. Mancinelli D. Marangotto J. Maratas J. F. Marchand U. Marconi C. Marin Benito M. Marinangeli P. Marino J. Marks P. J. Marshall G. Martellotti M. Martin M. Martinelli D. Martinez Santos F. Martinez Vidal A. Massafferri M. Materok R. Matev A. Mathad Z. Mathe C. Matteuzzi A. Mauri E. Maurice B. Maurin A. Mazurov M. McCann A. McNab R. McNulty J. V. Mead B. Meadows C. Meaux F. Meier N. Meinert D. Melnychuk M. Merk A. Merli E. Michielin D. A. Milanes E. Millard M. -N. Minard L. Minzoni D. S. Mitzel A. Mogini J. Molina Rodriguez T. Mombächer I. A. Monroy S. Monteil M. Morandin G. Morello M. J. Morello O. Morgunova J. Moron A. B. Morris R. Mountain F. Muheim M. Mulder C. H. Murphy D. Murray A. Mödden D. Müller J. Müller K. Müller V. Müller P. Naik T. Nakada R. Nandakumar A. Nandi T. Nanut I. Nasteva M. Needham N. Neri S. Neubert N. Neufeld M. Neuner T. D. Nguyen C. Nguyen-Mau S. Nieswand R. Niet N. Nikitin A. Nogay N. S. Nolte D. P. O'Hanlon A. Oblakowska-Mucha V. Obraztsov S. Ogilvy R. Oldeman C. J. G. Onderwater A. Ossowska J. M. Otalora Goicochea P. Owen A. Oyanguren P. R. Pais T. Pajero A. Palano M. Palutan G. Panshin A. Papanestis M. Pappagallo L. L. Pappalardo W. Parker C. Parkes G. Passaleva A. Pastore M. Patel C. Patrignani A. Pearce A. Pellegrino G. Penso M. Pepe Altarelli S. Perazzini D. Pereima P. Perret L. Pescatore K. Petridis A. Petrolini A. Petrov S. Petrucci M. Petruzzo B. Pietrzyk G. Pietrzyk M. Pikies M. Pili D. Pinci J. Pinzino F. Pisani A. Piucci V. Placinta S. Playfer J. Plews M. Plo Casasus F. Polci M. Poli Lener A. Poluektov N. Polukhina I. Polyakov E. Polycarpo G. J. 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 J. Qin R. Quagliani B. Quintana B. Rachwal J. H. Rademacker M. Rama M. Ramos Pernas M. S. Rangel F. Ratnikov G. Raven M. Ravonel Salzgeber M. Reboud F. Redi S. Reichert A. C. dos Reis F. Reiss C. Remon Alepuz Z. Ren V. Renaudin S. Ricciardi S. Richards K. Rinnert P. Robbe A. Robert A. B. Rodrigues E. Rodrigues J. A. Rodriguez Lopez M. Roehrken A. Rogozhnikov S. Roiser A. Rollings V. Romanovskiy A. Romero Vidal M. Rotondo M. S. Rudolph T. Ruf J. Ruiz Vidal J. J. Saborido Silva N. Sagidova B. Saitta V. Salustino Guimaraes C. Sanchez Gras C. Sanchez Mayordomo B. Sanmartin Sedes R. Santacesaria C. Santamarina Rios M. Santimaria E. Santovetti G. Sarpis A. Sarti C. Satriano A. Satta M. Saur D. Savrina S. Schael M. Schellenberg M. Schiller H. Schindler M. Schmelling T. Schmelzer B. Schmidt O. Schneider A. Schopper H. F. Schreiner M. Schubiger M. H. Schune R. Schwemmer B. Sciascia A. Sciubba A. Semennikov E. S. Sepulveda A. Sergi N. Serra J. Serrano L. Sestini A. Seuthe P. Seyfert M. Shapkin Y. Shcheglov T. Shears L. Shekhtman V. Shevchenko E. Shmanin B. G. Siddi R. Silva Coutinho L. Silva de Oliveira G. Simi S. Simone N. Skidmore T. Skwarnicki J. G. Smeaton E. Smith I. T. Smith M. Smith M. Soares l. Soares Lavra M. D. Sokoloff F. J. P. Soler B. Souza De Paula B. Spaan P. Spradlin F. Stagni M. Stahl S. Stahl P. Stefko S. Stefkova O. Steinkamp S. Stemmle O. Stenyakin M. Stepanova H. Stevens A. Stocchi S. Stone B. Storaci S. Stracka M. E. Stramaglia M. Straticiuc U. Straumann S. Strokov J. Sun L. Sun K. Swientek V. Syropoulos T. Szumlak M. Szymanski S. T'Jampens Z. Tang A. Tayduganov T. Tekampe G. Tellarini F. Teubert E. Thomas J. van Tilburg M. J. Tilley V. Tisserand M. Tobin S. Tolk L. Tomassetti D. Tonelli D. Y. Tou R. Tourinho Jadallah Aoude E. Tournefier M. Traill M. T. Tran A. Trisovic A. Tsaregorodtsev G. Tuci A. Tully N. Tuning A. Ukleja A. Usachov A. Ustyuzhanin U. Uwer A. Vagner V. Vagnoni A. Valassi S. Valat G. Valenti R. Vazquez Gomez P. Vazquez Regueiro S. Vecchi M. van Veghel J. J. Velthuis M. Veltri G. Veneziano A. Venkateswaran T. A. Verlage M. Vernet M. Veronesi N. V. Veronika M. Vesterinen J. V. Viana Barbosa D. Vieira M. Vieites Diaz H. Viemann X. Vilasis-Cardona A. Vitkovskiy M. Vitti V. Volkov A. Vollhardt B. Voneki A. Vorobyev V. Vorobyev J. A. de Vries C. Vázquez Sierra R. Waldi J. Walsh J. Wang M. Wang Y. Wang Z. Wang D. R. Ward H. M. Wark N. K. Watson D. Websdale A. Weiden C. Weisser M. Whitehead J. Wicht G. Wilkinson M. Wilkinson I. Williams M. R. J. Williams M. Williams T. Williams F. F. Wilson J. Wimberley M. Winn J. Wishahi W. Wislicki M. Witek G. Wormser S. A. Wotton K. Wyllie D. Xiao Y. Xie A. Xu M. Xu Q. Xu Z. Xu Z. Xu Z. Yang Z. Yang Y. Yao L. E. Yeomans H. Yin J. Yu X. Yuan O. Yushchenko K. A. Zarebski M. Zavertyaev D. Zhang L. Zhang W. C. Zhang Y. Zhang A. Zhelezov Y. Zheng X. Zhu V. Zhukov J. B. Zonneveld S. Zucchelli
























roman




EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH (CERN)



pdflatex

        

        


         CERN-EP-2018-190 
  
         LHCb-PAPER-2018-024 
  
         3 June, 2019 
 











  











[Authors are listed at the end of this paper.]








  The decay of the narrow resonance  can be used to determine the momentum in partially reconstructed decays without any assumptions on the decay products of the meson.
   This technique is employed for the first time to distinguish contributions from , , and higher-mass charmed states () in semileptonic decays by using the missing-mass distribution. The measurement is performed using a data sample corresponding to an integrated luminosity of 3.0 collected with the LHCb detector in pp collisions at center-of-mass energies of 7 and 8.  The resulting branching fractions relative to the inclusive X  are
  
    f_ = ( → )/( → X  )    = 0.25 ± 0.06, 
    
        f_  = ( →(→ X) )/( → X  )    = 0.21 ± 0.07,

  with f_ = 1 - f_ - f_ making up the remainder.













  Published in Phys. Rev. D99 (2019) 092009








 . .

































































plain 

arabic










§ INTRODUCTION




The composition of the inclusive bottom-to-charm semileptonic rate is not fully understood.  Measurements of the exclusive branching fractions for Dℓν and ℓν and corresponding decays with up to two additional charged pions <cit.> do not saturate the total bc semileptonic rate as determined from analysis of the charged lepton's kinematic moments <cit.>.
One way to resolve this inclusive–exclusive gap is to make measurements of relative rates between different final states. 

Semileptonic decays with excited charm states act as important backgrounds both to the exclusive decay channels BDℓν and Bℓν and for the study of semileptonic bu transitions. 
For example, understanding these backgrounds is essential for experimental tests of lepton flavor universality studied by comparing the rates of tauonic and muonic b-hadron decays, e.g. R(D^(*)) ≡(D^(*))/(D^(*)) <cit.>.[The inclusion of charge-conjugate processes is implied throughout.]

The largest contributions of excited charm states besides the D^*(2007)^0 or D^*(2010)^+ mesons come from the orbitally excited L=1 states D_0^*(2400), D_1(2420), D_1(2430), and D_2^*(2460), which have been individually measured <cit.>. We use the collective term D^** to refer to these as well as other resonances such as radially excited D mesons, and to nonresonant contributions with additional pions.


The contribution of excited states to the total semileptonic rate can be studied using B decays in which the B momentum is known. This allows one to calculate the mass of the undetected or “missing” part of the decay, and thus separate different excited D states.
In this paper we employ for the first time the technique described in Ref. <cit.> to accomplish this reconstruction in X decays, where X refers to any number of additional particles, without assumptions about the decay products of the meson. There are three narrow peaks in the  mass distribution just above the mass threshold from decays of the orbitally excited L=1 _s^** mesons <cit.>. We focus on the decay , which forms a narrow peak approximately 67 above the threshold,[Natural units with c = 1 are used throughout.] and has the largest yield of any observed excited state. By tagging mesons produced from the decay of these excited mesons, the energy can be determined up to a quadratic ambiguity using the and decay vertices and by imposing mass constraints for the and mesons. Since only approximately 1% of mesons originate from a decay, this method requires a large data set.

We determine the relative branching fractions of to , , and , referred to as f_, f_, and f_ respectively, in the X channel by fitting the distribution of the missing mass for  candidates.
A similar set of fractions (along with their counterparts), where the charge of the final state D meson is not specified, has been measured previously at the BaBar experiment <cit.>.
From the derivations in Ref. <cit.>, we expect based on previous branching fraction measurements

    f_   = ( → )/( → X  )           = 0.235 ± 0.011 ^+0.018_ -0.012 , 
    
    f_   = ( → )/( → X  )       = 0.564 ± 0.017 ^+0.042_ -0.028 , 
     
    f_   = ( →(→ X) )/( → X  )       = 0.201 ± 0.020 ^+0.039_ -0.060 ,

where the first uncertainty is experimental and the second gives an envelope of different extrapolation hypotheses to explain the inclusive–exclusive gap. Precise measurements of the relative branching fractions can distinguish between the hypotheses.
Higher values in the envelope (20% or more) would point towards a scenario in which there is a large contribution of unmeasured excited charm states. Lower fractions, closer to 14%, would suggest that the currently measured exclusive decays correctly describe the makeup of the total rate, and the inclusive–exclusive gap is due to other systematic effects.


A description of the data samples and selections used in this paper may be found in <ref>. Afterwards we discuss the missing mass reconstruction and related variables in <ref>.
Along with the signal decays, a large fraction of background decays are also selected. Yields and missing mass shapes must be determined for each of the background categories as described in <ref>. The most important background source is semileptonic decays of and mesons with the same final state as the signal that do not originate from decays. After accounting for other sources of background in <ref>, we estimate the yield and shape of this source in <ref>.
The relative branching fractions are determined using a template fit to the missing mass distribution as described in <ref>. The systematic uncertainties included in the fit are then described in <ref>. The final result is presented in <ref>.





§ DATA SAMPLE AND SELECTION



The detector <cit.> is a single-arm forward
spectrometer covering the  range 2<η <5,
designed for the study of particles containing or quarks. The detector includes a high-precision tracking system
consisting of a silicon-strip vertex detector surrounding the pp
interaction region <cit.>, a large-area silicon-strip detector located
upstream of a dipole magnet with a bending power of about
4 Tm, and three stations of silicon-strip detectors and straw
drift tubes <cit.> placed downstream of the magnet.
The tracking system provides a measurement of momentum, , of charged particles with
a relative uncertainty that varies from 0.5% at low momentum to 1.0% at 200.
The minimum distance of a track to a primary vertex (PV), the impact parameter (IP), 
is measured with a resolution of (15+29/),
where is the component of the momentum transverse to the beam, in .
Different types of charged hadrons are distinguished using information
from two ring-imaging Cherenkov detectors <cit.>. 
Photons, electrons and hadrons are identified by a calorimeter system consisting of
scintillating-pad and preshower detectors, an electromagnetic
calorimeter and a hadronic calorimeter. Muons are identified by a
system composed of alternating layers of iron and multiwire
proportional chambers <cit.>.
The online event selection is performed by a trigger <cit.>, 
which consists of a hardware stage, based on information from the calorimeter and muon
systems, followed by a software stage, which applies a full event
reconstruction.

We use data samples collected in 2011 and 2012, at center-of-mass energies of 7 and 8 respectively, corresponding to an integrated luminosity of 3.0.  All candidates are selected from  combinations, with .  The final-state particles are formed from high-quality tracks required to be inconsistent with being produced at any primary collision vertex in the event. Loose particle-identification requirements are also applied to these tracks. The  and  candidates must form a high-quality vertex, and their combined mass must lie in the range 18401890. The muon from the  candidate is required to pass the hardware trigger, which requires a transverse momentum of > 1.48 in the 7 data or > 1.76 in the 8 data. The software trigger requires a two-, three- or four-track secondary vertex with a significant displacement from
any primary pp interaction vertex, consistent with coming from a b hadron.  The  vertex must be of high quality, and well separated from the primary vertex.


After selecting candidates, we add candidate kaons consistent with originating from the primary vertex, referred to as prompt, to form the candidates.  To reduce background from misidentified pions from the primary interaction, we impose strong particle-identification requirements.  The selection requirements for the prompt kaons are optimized using the fully reconstructed decay . Signal decays produce a  pair; in addition to this opposite-sign kaon () data sample, we also use  same-sign kaon () combinations to help estimate backgrounds from data.

Samples of simulated events are used to model the  , , and  signal components. For the component, the simulation includes contributions from the four L=1 D mesons as well as a small contributions of nonresonant D^(*)π decays.
In the simulation, pp collisions are generated using
 <cit.> 
 with a specific configuration <cit.>.  Decays of hadronic particles
are described by  <cit.>, in which final-state
radiation is generated using  <cit.>. The
interaction of the generated particles with the detector, and its response,
are implemented using the toolkit <cit.> as described in
Ref. <cit.>.




§ RECONSTRUCTION OF THE  MESON MOMENTUM




We find the energy of the meson by using its flight direction from the primary vertex to the secondary  vertex; a diagram of the decay topology is shown in <ref>.  Applying mass constraints for the meson mass, m_B, and the hypothesized parent particle mass, m_BK, leaves a quadratic equation for the meson energy, E_B, derived in <ref>. 



 In carrying out the analysis we use two different quantities related to this calculation.
The first is the minimum mass of the  pair. For a particular vertex and kaon track, there is a minimum m_BK mass hypothesis for which the energy solutions are real. At this value, the discriminant of the quadratic equation is zero. This minimum mass value is given by

    = √( m_B^2 + m_K^2 + 2m_B√( p_K^2sin^2θ + m_K^2)),
 
where p_K is the kaon momentum in the laboratory frame, m_K is the kaon mass, and θ is the angle between the kaon direction and the direction from the primary to the secondary vertex.  The distribution of the difference between and the m_B + m_K threshold, =  - m_B - m_K,  shown in <ref> for both the and data samples, has excesses corresponding to the and states even for decays that are not fully reconstructed.  We use these distributions in a control region of 0 <  < 220 to constrain the total amount of decays and non-background contributions in our selection, as described in more detail in <ref>.




Decays of mesons and background candidates where a secondary kaon is misidentified as coming from the primary interaction have small values of ; the latter produces the increase near zero seen in <ref>. To remove these, we define our signal region for the missing mass fit as 30 <  < 67.


The second quantity is the missing mass, assuming the particles result from the decay of a meson (imposing m_BK = m_). The energy of the meson, E_B, is calculated as follows:

    E_B    = Δ^2/2E_K1/1 - (p_K/E_K)^2 cos^2θ[ 1 ±√(d) ], 
    whereΔ^2    = m_^2 - m_B^2 - m_K^2, 
    and
      d    = p_K^2/E_K^2cos^2θ - 4m_B^2p_K^2cos^2θ/Δ^4(1 - p_K^2/E_K^2cos^2θ ).

Once E_B has been determined, we calculate the missing mass squared

    = ( p_B - p_vis )^2,

where p_B is the four momentum calculated from E_B and the direction, and p_vis is the four momentum of the  combination. We require real solutions for <ref>. This keeps only candidates with less than the mass; candidates with > m_  - m_B - m_K, which is approximately 67, produce imaginary solutions. The variable is then used to perform the final fit to determine the relative branching fractions.

We keep only the physical solutions for E_B which are greater than the sum of the energies of the reconstructed decay products.
Based on simulation, approximately 75% of signal candidates have a physical solution.  For candidates with two physical solutions, the one with lower energy is correct 90% of the time. Only the lower energy solution is used for these candidates.
The difference Δ between the reconstructed missing-mass squared and the corresponding true values for different classes of solutions are shown in <ref>. When E_B is correctly reconstructed, the full-width at half maximum of the Δ distribution is approximately 0.4 and is consistent among the signal channels.
The resulting distributions for the signal decays to be used in the fit are shown in <ref>.










§ BACKGROUND ESTIMATION



The backgrounds to the signal candidates come from a number of different sources. For each of these sources, we estimate the overall yield as well as the missing-mass shapes. The most important sources are semileptonic decays of and mesons not originating from a or decay, which represent 83% of the total number of selected candidates.

The overall estimated background in the distribution is shown in <ref>. We make this estimation by first considering a number of smaller contributions not from semileptonic decays of and mesons:
  
  
  * misreconstructed backgrounds consisting of
  
  
  * non-backgrounds,
  
  *  combinations not from the same b-hadron decay,
  
  * backgrounds with a hadron misidentified as the muon;
  
  
  * and semileptonic decays to final states including a meson.

Together, these backgrounds total 8% of all selected candidates. We estimate their yield and shape in both the and the variables as described in <ref>. These can then be accounted for in both the distributions of the and data samples.
We then estimate the semileptonic and backgrounds as described in <ref>. The expectation for the contribution is subtracted from the remaining sample, producing an estimate for the shape of the contribution in that sample. These two distributions are then extrapolated to the sample to produce the background estimation. The difference between this estimation and the full yield is composed of signal decays.






 §.§ Backgrounds not from semileptonic decays of  and  mesons



Misreconstructed backgrounds are estimated using data-driven techniques. The yields and and shapes of backgrounds without a meson are estimated using sidebands around the mass peak. The sideband ranges chosen are from 17901830 and from 19001940. The difference of the shape between the left and right sidebands is negligible. Approximately 3% of the selected candidates come from this background.

Combinations of  not coming from a single b-hadron decay are estimated using a wrong-sign () control sample, assuming that the doubly Cabbibo-suppressed contribution from  is negligible.  Along with this estimation, the contributions from misidentified muons to both the signal and wrong-sign samples are estimated using a control sample with particle-identification requirements that remove true muons.  We then weight this sample using-particle identification efficiencies derived from calibration samples <cit.> to estimate the misidentified muon contamination. Together these two sources make up less than 1% of selected candidates.

We use a combination of data and simulation to estimate backgrounds from K^+ X , K^0 X , and  p X  decays.  In data, additional candidates identified as kaons or protons, which are inconsistent with being produced at any primary collision vertex, are combined with the  candidates.  This is done for both right- ( or p) and wrong-sign ( or ) combinations.  The wrong-sign combinations are used to model the combinatorial background in this selection.  Using a-two dimensional fit to the K or p mass and the track impact parameter with respect to the  vertex, we determine the and yields.

For the case, the resulting yield is corrected for efficiency, and for modes with neutral kaons, using simulation. We take the shape of the contribution in from simulation. There is an important contribution at low where the kaon from the decay points back to the primary vertex and is selected as the prompt kaon.  This contribution is not present in the data control sample because of the requirement for the additional kaon to be inconsistent with any primary vertex.  The final cut on does, however, remove this component from the signal region. The simulated samples well reproduce the shape of the distribution measured using the X selection.

Since the simulation does not reproduce well the shape in for the X control sample, the shape of the contribution to the main fit is instead derived from the control sample. We obtain it by taking the difference in the right- and wrong-sign kaon distributions, scaling the wrong-sign yield to match the combinatorial contribution found by the two dimensional fit described above. The contribution to the final selection is 3%, with a relative normalization uncertainty of 10%. For the case, the contribution is less than 1%. The shapes in both and are taken from the control sample, and scaled based on the efficiency in simulation.  The relative uncertainty on the normalization of this contribution is 20%.
The distribution for the sum of these backgrounds is shown in <ref>. 







 §.§ Backgrounds from semileptonic decays of  and  mesons



We first estimate the number of candidates in the signal region that do not come from decays.  This is done with a fit to the distribution in the control region after subtracting the backgrounds described in <ref>. The fit is done for three bins of prompt kaon to account for the different spectra of the and samples: 0.5 <  < 1.25, 1.25 <  < 2, and > 2.
The shapes for  signals as well as and ^*-, with ^*-γ, backgrounds are taken from simulation.  We model the background contribution using a fifth-order polynomial; the high order allows the fit to account for additional backgrounds peaking near = 0.

In an alternative approach, the sample is scaled to model the background in the sample. The scaling is based on a linear fit to the ratio between and samples in the region > 100, where the signal contribution is negligible. The distributions, showing the results of these two methods of background estimation, are shown in <ref>. We use the difference of the two methods to estimate the systematic uncertainty on the background yield.  




The two methods constrain the yield of non-decays as a function of , however the missing-mass shape in the channel must still be determined. For each type of background decay, the missing-mass distribution is the same in the and samples for a particular value of . This equivalence is tested using fully reconstructed  decays. However, since the missing mass also depends on the decay products, the distributions are different for and decays. The fraction of this background coming from decays is also different in the and samples.

We use the shape to model the background contribution in the sample, considering and decays separately. This is done by estimating first the contribution of decays to both the and channels. The remainder of the channel is used to model the shape of the contribution. The normalization of the background in the channel is then derived from the overall non-contribution with that from mesons removed.

To estimate the fractional contribution from decays in sample, we use the expected fraction resulting in the final state X based on measured branching fractions <cit.>.  The overlap with this measurement is removed by considering separately the ratio of contributions to the final state from and decays for the D^*(*) channels, r_D^*(*), with D^*(*)X.
These ratios are combined with the measured fractions f_ and f_. We assume equal production of and mesons.  The fraction of decays in the sample, f_, is thus given by

    1/f_   = (  X) + (  X)/(  X) 
       = 1 + [ ( )( X) + ( D^**+)( D^**+ X )  /(  X)  ]^-1
       = 1 + [ r_ f_D^*0 + r_D^**f_D^**0 ]^-1
       =  1 + [ (0.591± 0.024) f_D^*0 + (1.00 ± 0.23)f_D^**0 ]^-1.

The uncertainty on r_ comes chiefly from experimental uncertainty, while the dominant uncertainty on r_D^** comes from extrapolation to the unmeasured parts of the semileptonic width. The uncertainty is taken as one standard deviation of the full extrapolation envelope assuming a uniform distribution.  Using the central values of the expectations for f_ and f_ given in <ref>, the central value for f_ is 35%; variations within the uncertainties change it by approximately 2%. We then combine this value of f_ with an efficiency correction from simulation which depends on the lifetime difference between and mesons.

The contribution from mesons is studied similarly to the and backgrounds, by attaching an additional candidate identified as a pion to the  candidates.  We fit the π^± mass distributions, including peaking contributions from , D_1, and D_2^* mesons on top of a smooth distribution.  The normalizations of the peaks from the decay  ( D_2^*+) and the partially reconstructed decays  (  D_1^+    ) and  (  D_2^*+    ) show that there are more  candidates in the sample than there are in the sample. This is verified using fully reconstructed (892)^0 decays. Combining the ratios in the two channels, we find there is a 10% larger contribution of decays in the sample.

While the decays in the resonance peaks are dominated by either a or initial state, the other contributions to the π^± distributions are more difficult to disentangle. The combinatorial background is expected to be symmetric in  and , while decays produce  which also contribute equally to both distributions.  We therefore derive the missing-mass shape by subtracting the  shape from the  shape. Each shape is corrected for the efficiency to reconstruct the additional pion based on simulation. The resulting distribution is validated using a simulated mixture of decays.

We determine the total background shape from and decays in the sample by first removing the expected contribution from the initial sample's distribution. This is then scaled up by 10% to estimate the contribution to the sample.  The remainder of the sample, composed of decays, is scaled up so that when it is added to the estimate, the total number of background candidates in the sample is equal to the result of the fit.  We accomplish this procedure using an event-by-event weighting that accounts for the background yield as a function of .

Contributions not from semileptonic decays of and mesons that are subtracted from the sample (and contributions, combinatorial, and misidentified muons) are also weighted in the same manner before being subtracted to produce the final background template.




 §.§ Backgrounds from  and  decays


The final class of backgrounds are decays that produce a meson with a X final state that is not a semileptonic channel of interest. The shapes for semitauonic  X () decays and decays involving two charm mesons are estimated from simulation, and are included in the final fit. Contributions from or B^*-, where B^*-γ, are negligible after the requirement on the variable.





§ FIT DESCRIPTION



The fractions of interest, f_ and f_, are determined from a binned-template, maximum-likelihood fit to the missing-mass distribution of the sample. The signal fraction f_ is given by the remainder, 1 - f_ - f_. To control statistical fluctuations in the templates for the missing-mass tails, which are important for determining the content, a variable bin size is used for the template fit. The sum of the templates is allowed to vary bin-by-bin based on the combined statistical uncertainty of all templates.
This variation is included using a single nuisance parameter for each bin that is constrained by the statistical uncertainty.
It is dominated by the uncertainty of the sample used to create the combined and background template. The effect of these uncertainty parameters is determined analytically using the Barlow–Beeston method <cit.>.
Unless otherwise specified, we account for systematic uncertainties using nuisance parameters that are free to vary in the fit; these parameters are allowed to vary around their central values with a Gaussian constraint based on their uncertainty.

In total, the fit contains three signal and eight background templates: background from semileptonic and decays not from a decay, non-backgrounds,  combinations not from the same b-hadron decay, backgrounds with a hadron misidentified as the muon, , , decays with a semitauonic decay, and decays with a decay to two charm mesons. There are 18 free parameters in the fit, not including the nuisance parameters for the template statistical uncertainties.

The three templates describing the signal are obtained from simulation—exclusive , exclusive , and the sum of all modes; these are shown in <ref>. We also correct for the relative reconstruction and selection efficiencies between these samples, which are taken from simulation. Relative to the mode, the efficiency of the mode is 92% and that of the mode is 68%. In addition to the two signal fractions of interest, three more free parameters govern the shape changes from the variations of the form factors, and one parameter gives the overall signal yield.

The template describing the and backgrounds not coming from a meson is extrapolated from the sample as described in <ref>. Four free parameters describe the systematic variations of the normalization as a function of .
In the fit, the parameters r_ and r_D^** and the fractions f_ and f_ are used to calculate f_ for the current evaluation of the fit function. This variation is constrained by the uncertainties of r_ and r_D^**.  The current value of f_ is combined with a set of templates that vary f_ by ±1% to extrapolate from the nominal value and produce the estimated background shape for this evaluation. An additional uncertainty in this template comes from the shape of the component, which is controlled by one parameter.

The normalizations of the contributions from decays, decays, and decays involving misidentified muons are also allowed to vary. The data-driven background shapes for fake and combinatorial muons, and for and decays are described in <ref>.

The templates for the contribution of semitauonic decays of mesons from are obtained from simulation.  We determine the normalization relative to the semimuonic modes by deriving an effective ratio of semitauonic to semimuonic decays, R( X), using the Standard Model values <cit.> and the expected fractions of , , and ,

    R(  X) = R(D)f_ + R(D^*)f_ + R(D^**)f_,

where R(D) is the ratio (D)/(D), and R(D^*) and R(D^**) are the corresponding ratios in the other decay channels. This is combined with the τ→μ X branching fraction <cit.> and the relative efficiency to reconstruct τ decays taken from simulation.  The expected contribution is ( 1.5 ± 0.3 )% of the selected decays. The uncertainty is dominated by the difference of the Standard Model expectations and the world-average measured values of R(D) and R(D^*) <cit.>, which we take as a systematic uncertainty.

The other backgrounds coming from  decays are mesons decaying to double-charm states of various types. A simulated sample composed of many different decays producing  final states is used to determine the shape of this component.  The normalization of the resulting missing-mass template is expected to be about 1% of decays based on branching fractions, but is left unconstrained in the fit.




§ SYSTEMATIC UNCERTAINTIES





Each of the signal components has  systematic uncertainties associated to its shape.  The systematic uncertainty on the and components is estimated based on uncertainties in the form-factor parameters. We reweight our simulated samples using the Caprini–Lellouch–Neubert (CLN) expansion formalism <cit.>, with the uncertainties on the parameters taken from HFLAV <cit.>. This produces negligible changes in the missing mass template shapes compared to the other uncertainties in this analysis.

The uncertainty on the relative signal efficiencies is approximately 2%. We obtain the associated systematic uncertainty by repeating the fit with different efficiency values obtained by varying the efficiencies by their uncertainties.

For the template, in addition to a large variation in the form-factor distribution based on results from Ref. <cit.>, we create an alternative template with different branching fractions for the various resonant and nonresonant decay modes. The most important difference is the inclusion of a larger fraction of higher mass, nonresonant D^(*)π and D^(*)ππ decays, where the pions may be of any allowed charge combination. This shape is fixed in the template fit; a second fit with the alternative template is used to estimate the systematic uncertainty from this shape. During this second fit, the signal efficiency of the component is also adjusted along with the template. This uncertainty leads to the bands shown in <ref>.

For background contributions not from or semileptonic decays, we include individual uncertainties on their normalizations. Systematic variations in the shapes are dominated by the statistical bin-by-bin statistical uncertainty.

We consider a number of systematic uncertainties on the and contributions. The uncertainty due to the overall normalization comes from two sources. The statistical uncertainties in the polynomial background function of the fit are used to modify the template.  This corresponds to an uncertainty of less than 1% on the yield in each prompt kaon bin. We also use the alternative extrapolation using the ratio to provide an alternative normalization, giving an uncertainty of approximately 2%. Both of these uncertainties produce only small changes in the templates.
The uncertainties in r_ and r_D^** give the uncertainty on the fraction. The uncertainty in the shape is estimated from the uncertainty in the efficiency from simulation to reconstruct the pion in the π^± combination.


An estimated breakdown of the total statistical and systematic uncertainty is given in <ref>. The largest source of uncertainty is the statistical uncertainty from the extrapolated data sample. The uncertainty in the shape is also important because of its effect on the high tail.
Most systematic uncertainties are included in the fit with constrained nuisance parameters.  The only source for which the fit result has a significantly smaller uncertainty than the initial constraint is the normalization of the non-background from the extrapolation. 
For the final result, the total uncertainty is taken from the best fit, with the fixed systematic uncertainties for the relative signal efficiencies and the branching fractions from added in quadrature.




  




§ RESULTS AND CONCLUSIONS



The result of the template fit is shown in <ref>.
We find the parameters of interest

    f_   = 0.25 ± 0.06, 
    
      f_   = 0.21 ± 0.07,

where the uncertainty is the total due to statistical and systematic uncertainties.  Contours for the 68.3% and 95.5% confidence intervals for the nominal fit are shown in <ref>. From the conditional covariance of the two parameters of interest combined with the fit result using alternate branching fractions, the correlation coefficient of the two parameters is ρ = -0.38, which is dominated by the change in the alternate branching-fraction fit. The fraction f_ is equal to 1 - f_ - f_ = 0.54± 0.07, but this cannot be taken as an independent determination.






The results are compatible with expectations based on previous exclusive measurements <cit.>. Because of the uncertainty on the component, the results do not yet favor a particular explanation for the exclusive–inclusive gap.

We have demonstrated that the reconstruction of the momentum of decays with missing particles using decays is a viable method at the LHCb experiment. This technique requires much larger data sets than measurements with inclusive selections, but measuring the missing mass provides important discriminating power between different decay modes, and between signal and backgrounds. This is a promising method to employ with the additional data that the LHCb experiment has collected in Run 2 and will collect in the future.




§ ACKNOWLEDGEMENTS




We express our gratitude to our colleagues in the CERN
accelerator departments for the excellent performance of the LHC. We
thank the technical and administrative staff at the LHCb
institutes.
We acknowledge support from CERN and from the national agencies:
CAPES, CNPq, FAPERJ and FINEP (Brazil); 
MOST and NSFC (China); 
CNRS/IN2P3 (France); 
BMBF, DFG and MPG (Germany); 
INFN (Italy); 
NWO (Netherlands); 
MNiSW and NCN (Poland); 
MEN/IFA (Romania); 
MinES and FASO (Russia); 
MinECo (Spain); 
SNSF and SER (Switzerland); 
NASU (Ukraine); 
STFC (United Kingdom); 
NSF (USA).
We acknowledge the computing resources that are provided by CERN, IN2P3
(France), KIT and DESY (Germany), INFN (Italy), SURF (Netherlands),
PIC (Spain), GridPP (United Kingdom), RRCKI and Yandex
LLC (Russia), CSCS (Switzerland), IFIN-HH (Romania), CBPF (Brazil),
PL-GRID (Poland) and OSC (USA).
We are indebted to the communities behind the multiple open-source
software packages on which we depend.
Individual groups or members have received support from
AvH Foundation (Germany);
EPLANET, Marie Skłodowska-Curie Actions and ERC (European Union);
ANR, Labex P2IO and OCEVU, and Région Auvergne-Rhône-Alpes (France);
Key Research Program of Frontier Sciences of CAS, CAS PIFI, and the Thousand Talents Program (China);
RFBR, RSF and Yandex LLC (Russia);
GVA, XuntaGal and GENCAT (Spain);
the Royal Society
and the Leverhulme Trust (United Kingdom);
Laboratory Directed Research and Development program of LANL (USA).





§ APPENDIX







§ DERIVATION OF THE  MESON ENERGY




Consider a known momentum direction with unknown energy and a kaon of momentum p_K at an angle θ in the laboratory frame with respect to it.  Taking the direction as the z-axis, the squared mass of the  system is

    m_BK^2    = | ( E_B 
     0 
     0 
    √(E_B^2 - m_B^2)) + ( √(p_K^2 + m_K^2)
     p_Ksinθ
     0 
     p_Kcosθ) |^2. 
    For a particular m_BK hypothesis, <ref> can be written
       m_BK^2    = (E_B + √(p_K^2 + m_K^2))^2 - p_K^2sin^2θ
       = - ( √(E_B^2 - m_B^2) + p_Kcosθ)^2 
       = E_B^2 + 2E_BE_K +  m_K^2 + (p_K^2 - p_K^2sin^2θ) 
       =- E_B^2 + m_B^2 - 2p_Kcosθ√(E_B^2 - m_B^2) - p_K^2cos^2θ. 
    Rearranging terms, squaring to remove the root, and using Δ^2 = m_BK^2 - m_B^2 - m_K^2 gives
       0    = E_B^2( 4(E_K^2 - p_K^2cos^2θ)) + E_B(-4E_KΔ^2) 
       = + ( 4m_B^2p_K^2cos^2θ + Δ^4). The solution to the quadratic equation for E_B is
      E_B    = Δ^2/2E_K1/1 - (p_K/E_K)^2 cos^2θ[ 1 ±√(d) ],
    where
        d    = p_K^2/E_K^2cos^2θ - 4m_B^2p_K^2cos^2θ/Δ^4(1 - p_K^2/E_K^2cos^2θ ).





inbibliographytrue
LHCb








 
LHCb collaboration


R. Aaij^27,
B. Adeva^41,
M. Adinolfi^48,
C.A. Aidala^73,
Z. Ajaltouni^5,
S. Akar^59,
P. Albicocco^18,
J. Albrecht^10,
F. Alessio^42,
M. Alexander^53,
A. Alfonso Albero^40,
S. Ali^27,
G. Alkhazov^33,
P. Alvarez Cartelle^55,
A.A. Alves Jr^41,
S. Amato^2,
S. Amerio^23,
Y. Amhis^7,
L. An^3,
L. Anderlini^17,
G. Andreassi^43,
M. Andreotti^16,g,
J.E. Andrews^60,
R.B. Appleby^56,
F. Archilli^27,
P. d'Argent^12,
J. Arnau Romeu^6,
A. Artamonov^39,
M. Artuso^61,
K. Arzymatov^37,
E. Aslanides^6,
M. Atzeni^44,
B. Audurier^22,
S. Bachmann^12,
J.J. Back^50,
S. Baker^55,
V. Balagura^7,b,
W. Baldini^16,
A. Baranov^37,
R.J. Barlow^56,
S. Barsuk^7,
W. Barter^56,
F. Baryshnikov^70,
V. Batozskaya^31,
B. Batsukh^61,
V. Battista^43,
A. Bay^43,
J. Beddow^53,
F. Bedeschi^24,
I. Bediaga^1,
A. Beiter^61,
L.J. Bel^27,
S. Belin^22,
N. Beliy^63,
V. Bellee^43,
N. Belloli^20,i,
K. Belous^39,
I. Belyaev^34,42,
E. Ben-Haim^8,
G. Bencivenni^18,
S. Benson^27,
S. Beranek^9,
A. Berezhnoy^35,
R. Bernet^44,
D. Berninghoff^12,
E. Bertholet^8,
A. Bertolin^23,
C. Betancourt^44,
F. Betti^15,42,
M.O. Bettler^49,
M. van Beuzekom^27,
Ia. Bezshyiko^44,
S. Bhasin^48,
J. Bhom^29,
S. Bifani^47,
P. Billoir^8,
A. Birnkraut^10,
A. Bizzeti^17,u,
M. Bjørn^57,
M.P. Blago^42,
T. Blake^50,
F. Blanc^43,
S. Blusk^61,
D. Bobulska^53,
V. Bocci^26,
O. Boente Garcia^41,
T. Boettcher^58,
A. Bondar^38,w,
N. Bondar^33,
S. Borghi^56,42,
M. Borisyak^37,
M. Borsato^41,
F. Bossu^7,
M. Boubdir^9,
T.J.V. Bowcock^54,
C. Bozzi^16,42,
S. Braun^12,
M. Brodski^42,
J. Brodzicka^29,
A. Brossa Gonzalo^50,
D. Brundu^22,
E. Buchanan^48,
A. Buonaura^44,
C. Burr^56,
A. Bursche^22,
J. Buytaert^42,
W. Byczynski^42,
S. Cadeddu^22,
H. Cai^64,
R. Calabrese^16,g,
R. Calladine^47,
M. Calvi^20,i,
M. Calvo Gomez^40,m,
A. Camboni^40,m,
P. Campana^18,
D.H. Campora Perez^42,
L. Capriotti^56,
A. Carbone^15,e,
G. Carboni^25,
R. Cardinale^19,h,
A. Cardini^22,
P. Carniti^20,i,
L. Carson^52,
K. Carvalho Akiba^2,
G. Casse^54,
L. Cassina^20,
M. Cattaneo^42,
G. Cavallero^19,h,
R. Cenci^24,p,
D. Chamont^7,
M.G. Chapman^48,
M. Charles^8,
Ph. Charpentier^42,
G. Chatzikonstantinidis^47,
M. Chefdeville^4,
V. Chekalina^37,
C. Chen^3,
S. Chen^22,
S.-G. Chitic^42,
V. Chobanova^41,
M. Chrzaszcz^42,
A. Chubykin^33,
P. Ciambrone^18,
X. Cid Vidal^41,
G. Ciezarek^42,
P.E.L. Clarke^52,
M. Clemencic^42,
H.V. Cliff^49,
J. Closier^42,
V. Coco^42,
J.A.B. Coelho^7,
J. Cogan^6,
E. Cogneras^5,
L. Cojocariu^32,
P. Collins^42,
T. Colombo^42,
A. Comerma-Montells^12,
A. Contu^22,
G. Coombs^42,
S. Coquereau^40,
G. Corti^42,
M. Corvo^16,g,
C.M. Costa Sobral^50,
B. Couturier^42,
G.A. Cowan^52,
D.C. Craik^58,
A. Crocombe^50,
M. Cruz Torres^1,
R. Currie^52,
C. D'Ambrosio^42,
F. Da Cunha Marinho^2,
C.L. Da Silva^74,
E. Dall'Occo^27,
J. Dalseno^48,
A. Danilina^34,
A. Davis^3,
O. De Aguiar Francisco^42,
K. De Bruyn^42,
S. De Capua^56,
M. De Cian^43,
J.M. De Miranda^1,
L. De Paula^2,
M. De Serio^14,d,
P. De Simone^18,
C.T. Dean^53,
D. Decamp^4,
L. Del Buono^8,
B. Delaney^49,
H.-P. Dembinski^11,
M. Demmer^10,
A. Dendek^30,
D. Derkach^37,
O. Deschamps^5,
F. Desse^7,
F. Dettori^54,
B. Dey^65,
A. Di Canto^42,
P. Di Nezza^18,
S. Didenko^70,
H. Dijkstra^42,
F. Dordei^42,
M. Dorigo^42,y,
A. Dosil Suárez^41,
L. Douglas^53,
A. Dovbnya^45,
K. Dreimanis^54,
L. Dufour^27,
G. Dujany^8,
P. Durante^42,
J.M. Durham^74,
D. Dutta^56,
R. Dzhelyadin^39,
M. Dziewiecki^12,
A. Dziurda^29,
A. Dzyuba^33,
S. Easo^51,
U. Egede^55,
V. Egorychev^34,
S. Eidelman^38,w,
S. Eisenhardt^52,
U. Eitschberger^10,
R. Ekelhof^10,
L. Eklund^53,
S. Ely^61,
A. Ene^32,
S. Escher^9,
S. Esen^27,
T. Evans^59,
A. Falabella^15,
N. Farley^47,
S. Farry^54,
D. Fazzini^20,42,i,
L. Federici^25,
P. Fernandez Declara^42,
A. Fernandez Prieto^41,
F. Ferrari^15,
L. Ferreira Lopes^43,
F. Ferreira Rodrigues^2,
M. Ferro-Luzzi^42,
S. Filippov^36,
R.A. Fini^14,
M. Fiorini^16,g,
M. Firlej^30,
C. Fitzpatrick^43,
T. Fiutowski^30,
F. Fleuret^7,b,
M. Fontana^22,42,
F. Fontanelli^19,h,
R. Forty^42,
V. Franco Lima^54,
M. Frank^42,
C. Frei^42,
J. Fu^21,q,
W. Funk^42,
C. Färber^42,
M. Féo Pereira Rivello Carvalho^27,
E. Gabriel^52,
A. Gallas Torreira^41,
D. Galli^15,e,
S. Gallorini^23,
S. Gambetta^52,
Y. Gan^3,
M. Gandelman^2,
P. Gandini^21,
Y. Gao^3,
L.M. Garcia Martin^72,
B. Garcia Plana^41,
J. García Pardiñas^44,
J. Garra Tico^49,
L. Garrido^40,
D. Gascon^40,
C. Gaspar^42,
L. Gavardi^10,
G. Gazzoni^5,
D. Gerick^12,
E. Gersabeck^56,
M. Gersabeck^56,
T. Gershon^50,
D. Gerstel^6,
Ph. Ghez^4,
S. Gianì^43,
V. Gibson^49,
O.G. Girard^43,
L. Giubega^32,
K. Gizdov^52,
V.V. Gligorov^8,
D. Golubkov^34,
A. Golutvin^55,70,
A. Gomes^1,a,
I.V. Gorelov^35,
C. Gotti^20,i,
E. Govorkova^27,
J.P. Grabowski^12,
R. Graciani Diaz^40,
L.A. Granado Cardoso^42,
E. Graugés^40,
E. Graverini^44,
G. Graziani^17,
A. Grecu^32,
R. Greim^27,
P. Griffith^22,
L. Grillo^56,
L. Gruber^42,
B.R. Gruberg Cazon^57,
O. Grünberg^67,
C. Gu^3,
E. Gushchin^36,
Yu. Guz^39,42,
T. Gys^42,
C. Göbel^62,
T. Hadavizadeh^57,
C. Hadjivasiliou^5,
G. Haefeli^43,
C. Haen^42,
S.C. Haines^49,
B. Hamilton^60,
X. Han^12,
T.H. Hancock^57,
S. Hansmann-Menzemer^12,
N. Harnew^57,
S.T. Harnew^48,
T. Harrison^54,
C. Hasse^42,
M. Hatch^42,
J. He^63,
M. Hecker^55,
K. Heinicke^10,
A. Heister^10,
K. Hennessy^54,
L. Henry^72,
E. van Herwijnen^42,
M. Heß^67,
A. Hicheur^2,
R. Hidalgo Charman^56,
D. Hill^57,
M. Hilton^56,
P.H. Hopchev^43,
W. Hu^65,
W. Huang^63,
Z.C. Huard^59,
W. Hulsbergen^27,
T. Humair^55,
M. Hushchyn^37,
D. Hutchcroft^54,
D. Hynds^27,
P. Ibis^10,
M. Idzik^30,
P. Ilten^47,
K. Ivshin^33,
R. Jacobsson^42,
J. Jalocha^57,
E. Jans^27,
A. Jawahery^60,
F. Jiang^3,
M. John^57,
D. Johnson^42,
C.R. Jones^49,
C. Joram^42,
B. Jost^42,
N. Jurik^57,
S. Kandybei^45,
M. Karacson^42,
J.M. Kariuki^48,
S. Karodia^53,
N. Kazeev^37,
M. Kecke^12,
F. Keizer^49,
M. Kelsey^61,
M. Kenzie^49,
T. Ketel^28,
E. Khairullin^37,
B. Khanji^12,
C. Khurewathanakul^43,
K.E. Kim^61,
T. Kirn^9,
S. Klaver^18,
K. Klimaszewski^31,
T. Klimkovich^11,
S. Koliiev^46,
M. Kolpin^12,
R. Kopecna^12,
P. Koppenburg^27,
I. Kostiuk^27,
S. Kotriakhova^33,
M. Kozeiha^5,
L. Kravchuk^36,
M. Kreps^50,
F. Kress^55,
P. Krokovny^38,w,
W. Krupa^30,
W. Krzemien^31,
W. Kucewicz^29,l,
M. Kucharczyk^29,
V. Kudryavtsev^38,w,
A.K. Kuonen^43,
T. Kvaratskheliya^34,42,
D. Lacarrere^42,
G. Lafferty^56,
A. Lai^22,
D. Lancierini^44,
G. Lanfranchi^18,
C. Langenbruch^9,
T. Latham^50,
C. Lazzeroni^47,
R. Le Gac^6,
A. Leflat^35,
J. Lefrançois^7,
R. Lefèvre^5,
F. Lemaitre^42,
O. Leroy^6,
T. Lesiak^29,
B. Leverington^12,
P.-R. Li^63,
T. Li^3,
Z. Li^61,
X. Liang^61,
T. Likhomanenko^69,
R. Lindner^42,
F. Lionetto^44,
V. Lisovskyi^7,
X. Liu^3,
D. Loh^50,
A. Loi^22,
I. Longstaff^53,
J.H. Lopes^2,
G.H. Lovell^49,
D. Lucchesi^23,o,
M. Lucio Martinez^41,
A. Lupato^23,
E. Luppi^16,g,
O. Lupton^42,
A. Lusiani^24,
X. Lyu^63,
F. Machefert^7,
F. Maciuc^32,
V. Macko^43,
P. Mackowiak^10,
S. Maddrell-Mander^48,
O. Maev^33,42,
K. Maguire^56,
D. Maisuzenko^33,
M.W. Majewski^30,
S. Malde^57,
B. Malecki^29,
A. Malinin^69,
T. Maltsev^38,w,
G. Manca^22,f,
G. Mancinelli^6,
D. Marangotto^21,q,
J. Maratas^5,v,
J.F. Marchand^4,
U. Marconi^15,
C. Marin Benito^7,
M. Marinangeli^43,
P. Marino^43,
J. Marks^12,
P.J. Marshall^54,
G. Martellotti^26,
M. Martin^6,
M. Martinelli^42,
D. Martinez Santos^41,
F. Martinez Vidal^72,
A. Massafferri^1,
M. Materok^9,
R. Matev^42,
A. Mathad^50,
Z. Mathe^42,
C. Matteuzzi^20,
A. Mauri^44,
E. Maurice^7,b,
B. Maurin^43,
A. Mazurov^47,
M. McCann^55,42,
A. McNab^56,
R. McNulty^13,
J.V. Mead^54,
B. Meadows^59,
C. Meaux^6,
F. Meier^10,
N. Meinert^67,
D. Melnychuk^31,
M. Merk^27,
A. Merli^21,q,
E. Michielin^23,
D.A. Milanes^66,
E. Millard^50,
M.-N. Minard^4,
L. Minzoni^16,g,
D.S. Mitzel^12,
A. Mogini^8,
J. Molina Rodriguez^1,z,
T. Mombächer^10,
I.A. Monroy^66,
S. Monteil^5,
M. Morandin^23,
G. Morello^18,
M.J. Morello^24,t,
O. Morgunova^69,
J. Moron^30,
A.B. Morris^6,
R. Mountain^61,
F. Muheim^52,
M. Mulder^27,
C.H. Murphy^57,
D. Murray^56,
A. Mödden ^10,
D. Müller^42,
J. Müller^10,
K. Müller^44,
V. Müller^10,
P. Naik^48,
T. Nakada^43,
R. Nandakumar^51,
A. Nandi^57,
T. Nanut^43,
I. Nasteva^2,
M. Needham^52,
N. Neri^21,
S. Neubert^12,
N. Neufeld^42,
M. Neuner^12,
T.D. Nguyen^43,
C. Nguyen-Mau^43,n,
S. Nieswand^9,
R. Niet^10,
N. Nikitin^35,
A. Nogay^69,
N.S. Nolte^42,
D.P. O'Hanlon^15,
A. Oblakowska-Mucha^30,
V. Obraztsov^39,
S. Ogilvy^18,
R. Oldeman^22,f,
C.J.G. Onderwater^68,
A. Ossowska^29,
J.M. Otalora Goicochea^2,
P. Owen^44,
A. Oyanguren^72,
P.R. Pais^43,
T. Pajero^24,t,
A. Palano^14,
M. Palutan^18,42,
G. Panshin^71,
A. Papanestis^51,
M. Pappagallo^52,
L.L. Pappalardo^16,g,
W. Parker^60,
C. Parkes^56,
G. Passaleva^17,42,
A. Pastore^14,
M. Patel^55,
C. Patrignani^15,e,
A. Pearce^42,
A. Pellegrino^27,
G. Penso^26,
M. Pepe Altarelli^42,
S. Perazzini^42,
D. Pereima^34,
P. Perret^5,
L. Pescatore^43,
K. Petridis^48,
A. Petrolini^19,h,
A. Petrov^69,
S. Petrucci^52,
M. Petruzzo^21,q,
B. Pietrzyk^4,
G. Pietrzyk^43,
M. Pikies^29,
M. Pili^57,
D. Pinci^26,
J. Pinzino^42,
F. Pisani^42,
A. Piucci^12,
V. Placinta^32,
S. Playfer^52,
J. Plews^47,
M. Plo Casasus^41,
F. Polci^8,
M. Poli Lener^18,
A. Poluektov^50,
N. Polukhina^70,c,
I. Polyakov^61,
E. Polycarpo^2,
G.J. Pomery^48,
S. Ponce^42,
A. Popov^39,
D. Popov^47,11,
S. Poslavskii^39,
C. Potterat^2,
E. Price^48,
J. Prisciandaro^41,
C. Prouve^48,
V. Pugatch^46,
A. Puig Navarro^44,
H. Pullen^57,
G. Punzi^24,p,
W. Qian^63,
J. Qin^63,
R. Quagliani^8,
B. Quintana^5,
B. Rachwal^30,
J.H. Rademacker^48,
M. Rama^24,
M. Ramos Pernas^41,
M.S. Rangel^2,
F. Ratnikov^37,x,
G. Raven^28,
M. Ravonel Salzgeber^42,
M. Reboud^4,
F. Redi^43,
S. Reichert^10,
A.C. dos Reis^1,
F. Reiss^8,
C. Remon Alepuz^72,
Z. Ren^3,
V. Renaudin^7,
S. Ricciardi^51,
S. Richards^48,
K. Rinnert^54,
P. Robbe^7,
A. Robert^8,
A.B. Rodrigues^43,
E. Rodrigues^59,
J.A. Rodriguez Lopez^66,
M. Roehrken^42,
A. Rogozhnikov^37,
S. Roiser^42,
A. Rollings^57,
V. Romanovskiy^39,
A. Romero Vidal^41,
M. Rotondo^18,
M.S. Rudolph^61,
T. Ruf^42,
J. Ruiz Vidal^72,
J.J. Saborido Silva^41,
N. Sagidova^33,
B. Saitta^22,f,
V. Salustino Guimaraes^62,
C. Sanchez Gras^27,
C. Sanchez Mayordomo^72,
B. Sanmartin Sedes^41,
R. Santacesaria^26,
C. Santamarina Rios^41,
M. Santimaria^18,
E. Santovetti^25,j,
G. Sarpis^56,
A. Sarti^18,k,
C. Satriano^26,s,
A. Satta^25,
M. Saur^63,
D. Savrina^34,35,
S. Schael^9,
M. Schellenberg^10,
M. Schiller^53,
H. Schindler^42,
M. Schmelling^11,
T. Schmelzer^10,
B. Schmidt^42,
O. Schneider^43,
A. Schopper^42,
H.F. Schreiner^59,
M. Schubiger^43,
M.H. Schune^7,
R. Schwemmer^42,
B. Sciascia^18,
A. Sciubba^26,k,
A. Semennikov^34,
E.S. Sepulveda^8,
A. Sergi^47,42,
N. Serra^44,
J. Serrano^6,
L. Sestini^23,
A. Seuthe^10,
P. Seyfert^42,
M. Shapkin^39,
Y. Shcheglov^33,†,
T. Shears^54,
L. Shekhtman^38,w,
V. Shevchenko^69,
E. Shmanin^70,
B.G. Siddi^16,
R. Silva Coutinho^44,
L. Silva de Oliveira^2,
G. Simi^23,o,
S. Simone^14,d,
N. Skidmore^12,
T. Skwarnicki^61,
J.G. Smeaton^49,
E. Smith^9,
I.T. Smith^52,
M. Smith^55,
M. Soares^15,
l. Soares Lavra^1,
M.D. Sokoloff^59,
F.J.P. Soler^53,
B. Souza De Paula^2,
B. Spaan^10,
P. Spradlin^53,
F. Stagni^42,
M. Stahl^12,
S. Stahl^42,
P. Stefko^43,
S. Stefkova^55,
O. Steinkamp^44,
S. Stemmle^12,
O. Stenyakin^39,
M. Stepanova^33,
H. Stevens^10,
A. Stocchi^7,
S. Stone^61,
B. Storaci^44,
S. Stracka^24,p,
M.E. Stramaglia^43,
M. Straticiuc^32,
U. Straumann^44,
S. Strokov^71,
J. Sun^3,
L. Sun^64,
K. Swientek^30,
V. Syropoulos^28,
T. Szumlak^30,
M. Szymanski^63,
S. T'Jampens^4,
Z. Tang^3,
A. Tayduganov^6,
T. Tekampe^10,
G. Tellarini^16,
F. Teubert^42,
E. Thomas^42,
J. van Tilburg^27,
M.J. Tilley^55,
V. Tisserand^5,
M. Tobin^30,
S. Tolk^42,
L. Tomassetti^16,g,
D. Tonelli^24,
D.Y. Tou^8,
R. Tourinho Jadallah Aoude^1,
E. Tournefier^4,
M. Traill^53,
M.T. Tran^43,
A. Trisovic^49,
A. Tsaregorodtsev^6,
G. Tuci^24,
A. Tully^49,
N. Tuning^27,42,
A. Ukleja^31,
A. Usachov^7,
A. Ustyuzhanin^37,
U. Uwer^12,
A. Vagner^71,
V. Vagnoni^15,
A. Valassi^42,
S. Valat^42,
G. Valenti^15,
R. Vazquez Gomez^42,
P. Vazquez Regueiro^41,
S. Vecchi^16,
M. van Veghel^27,
J.J. Velthuis^48,
M. Veltri^17,r,
G. Veneziano^57,
A. Venkateswaran^61,
T.A. Verlage^9,
M. Vernet^5,
M. Veronesi^27,
N.V. Veronika^13,
M. Vesterinen^57,
J.V. Viana Barbosa^42,
D.  Vieira^63,
M. Vieites Diaz^41,
H. Viemann^67,
X. Vilasis-Cardona^40,m,
A. Vitkovskiy^27,
M. Vitti^49,
V. Volkov^35,
A. Vollhardt^44,
B. Voneki^42,
A. Vorobyev^33,
V. Vorobyev^38,w,
J.A. de Vries^27,
C. Vázquez Sierra^27,
R. Waldi^67,
J. Walsh^24,
J. Wang^61,
M. Wang^3,
Y. Wang^65,
Z. Wang^44,
D.R. Ward^49,
H.M. Wark^54,
N.K. Watson^47,
D. Websdale^55,
A. Weiden^44,
C. Weisser^58,
M. Whitehead^9,
J. Wicht^50,
G. Wilkinson^57,
M. Wilkinson^61,
I. Williams^49,
M.R.J. Williams^56,
M. Williams^58,
T. Williams^47,
F.F. Wilson^51,42,
J. Wimberley^60,
M. Winn^7,
J. Wishahi^10,
W. Wislicki^31,
M. Witek^29,
G. Wormser^7,
S.A. Wotton^49,
K. Wyllie^42,
D. Xiao^65,
Y. Xie^65,
A. Xu^3,
M. Xu^65,
Q. Xu^63,
Z. Xu^3,
Z. Xu^4,
Z. Yang^3,
Z. Yang^60,
Y. Yao^61,
L.E. Yeomans^54,
H. Yin^65,
J. Yu^65,ab,
X. Yuan^61,
O. Yushchenko^39,
K.A. Zarebski^47,
M. Zavertyaev^11,c,
D. Zhang^65,
L. Zhang^3,
W.C. Zhang^3,aa,
Y. Zhang^7,
A. Zhelezov^12,
Y. Zheng^63,
X. Zhu^3,
V. Zhukov^9,35,
J.B. Zonneveld^52,
S. Zucchelli^15.

^1Centro Brasileiro de Pesquisas Físicas (CBPF), Rio de Janeiro, Brazil

^2Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil

^3Center for High Energy Physics, Tsinghua University, Beijing, China

^4Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IN2P3-LAPP, Annecy, France

^5Clermont Université, Université Blaise Pascal, CNRS/IN2P3, LPC, Clermont-Ferrand, France

^6Aix Marseille Univ, CNRS/IN2P3, CPPM, Marseille, France

^7LAL, Univ. Paris-Sud, CNRS/IN2P3, Université Paris-Saclay, Orsay, France

^8LPNHE, Sorbonne Université, Paris Diderot Sorbonne Paris Cité, CNRS/IN2P3, Paris, France

^9I. Physikalisches Institut, RWTH Aachen University, Aachen, Germany

^10Fakultät Physik, Technische Universität Dortmund, Dortmund, Germany

^11Max-Planck-Institut für Kernphysik (MPIK), Heidelberg, Germany

^12Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany

^13School of Physics, University College Dublin, Dublin, Ireland

^14INFN Sezione di Bari, Bari, Italy

^15INFN Sezione di Bologna, Bologna, Italy

^16INFN Sezione di Ferrara, Ferrara, Italy

^17INFN Sezione di Firenze, Firenze, Italy

^18INFN Laboratori Nazionali di Frascati, Frascati, Italy

^19INFN Sezione di Genova, Genova, Italy

^20INFN Sezione di Milano-Bicocca, Milano, Italy

^21INFN Sezione di Milano, Milano, Italy

^22INFN Sezione di Cagliari, Monserrato, Italy

^23INFN Sezione di Padova, Padova, Italy

^24INFN Sezione di Pisa, Pisa, Italy

^25INFN Sezione di Roma Tor Vergata, Roma, Italy

^26INFN Sezione di Roma La Sapienza, Roma, Italy

^27Nikhef National Institute for Subatomic Physics, Amsterdam, Netherlands

^28Nikhef National Institute for Subatomic Physics and VU University Amsterdam, Amsterdam, Netherlands

^29Henryk Niewodniczanski Institute of Nuclear Physics  Polish Academy of Sciences, Kraków, Poland

^30AGH - University of Science and Technology, Faculty of Physics and Applied Computer Science, Kraków, Poland

^31National Center for Nuclear Research (NCBJ), Warsaw, Poland

^32Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest-Magurele, Romania

^33Petersburg Nuclear Physics Institute (PNPI), Gatchina, Russia

^34Institute of Theoretical and Experimental Physics (ITEP), Moscow, Russia

^35Institute of Nuclear Physics, Moscow State University (SINP MSU), Moscow, Russia

^36Institute for Nuclear Research of the Russian Academy of Sciences (INR RAS), Moscow, Russia

^37Yandex School of Data Analysis, Moscow, Russia

^38Budker Institute of Nuclear Physics (SB RAS), Novosibirsk, Russia

^39Institute for High Energy Physics (IHEP), Protvino, Russia

^40ICCUB, Universitat de Barcelona, Barcelona, Spain

^41Instituto Galego de Física de Altas Enerxías (IGFAE), Universidade de Santiago de Compostela, Santiago de Compostela, Spain

^42European Organization for Nuclear Research (CERN), Geneva, Switzerland

^43Institute of Physics, Ecole Polytechnique  Fédérale de Lausanne (EPFL), Lausanne, Switzerland

^44Physik-Institut, Universität Zürich, Zürich, Switzerland

^45NSC Kharkiv Institute of Physics and Technology (NSC KIPT), Kharkiv, Ukraine

^46Institute for Nuclear Research of the National Academy of Sciences (KINR), Kyiv, Ukraine

^47University of Birmingham, Birmingham, United Kingdom

^48H.H. Wills Physics Laboratory, University of Bristol, Bristol, United Kingdom

^49Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom

^50Department of Physics, University of Warwick, Coventry, United Kingdom

^51STFC Rutherford Appleton Laboratory, Didcot, United Kingdom

^52School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom

^53School of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom

^54Oliver Lodge Laboratory, University of Liverpool, Liverpool, United Kingdom

^55Imperial College London, London, United Kingdom

^56School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom

^57Department of Physics, University of Oxford, Oxford, United Kingdom

^58Massachusetts Institute of Technology, Cambridge, MA, United States

^59University of Cincinnati, Cincinnati, OH, United States

^60University of Maryland, College Park, MD, United States

^61Syracuse University, Syracuse, NY, United States

^62Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio), Rio de Janeiro, Brazil, associated to ^2

^63University of Chinese Academy of Sciences, Beijing, China, associated to ^3

^64School of Physics and Technology, Wuhan University, Wuhan, China, associated to ^3

^65Institute of Particle Physics, Central China Normal University, Wuhan, Hubei, China, associated to ^3

^66Departamento de Fisica , Universidad Nacional de Colombia, Bogota, Colombia, associated to ^8

^67Institut für Physik, Universität Rostock, Rostock, Germany, associated to ^12

^68Van Swinderen Institute, University of Groningen, Groningen, Netherlands, associated to ^27

^69National Research Centre Kurchatov Institute, Moscow, Russia, associated to ^34

^70National University of Science and Technology "MISIS", Moscow, Russia, associated to ^34

^71National Research Tomsk Polytechnic University, Tomsk, Russia, associated to ^34

^72Instituto de Fisica Corpuscular, Centro Mixto Universidad de Valencia - CSIC, Valencia, Spain, associated to ^40

^73University of Michigan, Ann Arbor, United States, associated to ^61

^74Los Alamos National Laboratory (LANL), Los Alamos, United States, associated to ^61

^aUniversidade Federal do Triângulo Mineiro (UFTM), Uberaba-MG, Brazil

^bLaboratoire Leprince-Ringuet, Palaiseau, France

^cP.N. Lebedev Physical Institute, Russian Academy of Science (LPI RAS), Moscow, Russia

^dUniversità di Bari, Bari, Italy

^eUniversità di Bologna, Bologna, Italy

^fUniversità di Cagliari, Cagliari, Italy

^gUniversità di Ferrara, Ferrara, Italy

^hUniversità di Genova, Genova, Italy

^iUniversità di Milano Bicocca, Milano, Italy

^jUniversità di Roma Tor Vergata, Roma, Italy

^kUniversità di Roma La Sapienza, Roma, Italy

^lAGH - University of Science and Technology, Faculty of Computer Science, Electronics and Telecommunications, Kraków, Poland

^mLIFAELS, La Salle, Universitat Ramon Llull, Barcelona, Spain

^nHanoi University of Science, Hanoi, Vietnam

^oUniversità di Padova, Padova, Italy

^pUniversità di Pisa, Pisa, Italy

^qUniversità degli Studi di Milano, Milano, Italy

^rUniversità di Urbino, Urbino, Italy

^sUniversità della Basilicata, Potenza, Italy

^tScuola Normale Superiore, Pisa, Italy

^uUniversità di Modena e Reggio Emilia, Modena, Italy

^vMSU - Iligan Institute of Technology (MSU-IIT), Iligan, Philippines

^wNovosibirsk State University, Novosibirsk, Russia

^xNational Research University Higher School of Economics, Moscow, Russia

^ySezione INFN di Trieste, Trieste, Italy

^zEscuela Agrícola Panamericana, San Antonio de Oriente, Honduras

^aaSchool of Physics and Information Technology, Shaanxi Normal University (SNNU), Xi'an, China

^abPhysics and Micro Electronic College, Hunan University, Changsha City, China

^†Deceased


















