First Observation of the Doubly Charmed Baryon Decay $\Xi_{cc}^{++}\rightarrow \Xi_{c}^{+}\pi^{+}$

EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH (CERN)

CERN-EP-2018-172 LHCb-PAPER-2018-026 October 18, 2018

First observation of the doubly

charmed baryon decay

Ξ

_cc

++

→ Ξ

_c

+

π

+

LHCb collaboration†

Abstract The doubly charmed baryon decay Ξ++

cc → Ξc+π+ is observed for the first time,

with a statistical significance of 5.9σ, confirming a recent observation of the baryon in the Λ+

cK−π+π+ final state. The data sample used corresponds to an integrated

luminosity of 1.7 fb−1, collected by the LHCb experiment in pp collisions at a center-of-mass energy of 13 TeV. The Ξ++

cc mass is measured to be

3620.6± 1.5 (stat) ± 0.4 (syst) ± 0.3 (Ξ+

c ) MeV/c2,

and is consistent with the previous result. The ratio of branching fractions between the decay modes is measured to be

B(Ξ++

cc → Ξc+π+)× B(Ξc+→ pK−π+)

B(Ξ++

cc → Λ+cK−π+π+)× B(Λ+c → pK−π+)

= 0.035_{± 0.009 (stat) ± 0.003 (syst).}

Published in Phys. Rev. Lett. 121, 162002 (2018)

c

2018 CERN for the benefit of the LHCb collaboration. CC-BY-4.0 licence. †_{Authors are listed at the end of this paper.}

The recent observation by the LHCb collaboration [1] of a new state that is con-sistent with the doubly charmed baryon Ξ++

cc , opens a new field of research studying

the properties of baryons containing two heavy quarks, providing a unique environ-ment for testing models of quantum chromodynamics (QCD). In studies of a sample of Ξ++

cc decays to the final state Λ+cK

−_π+_π+_{, with Λ}+

c → pK

−_π+_{, its mass was found to be}

3621.40 _{± 0.72 (stat) ± 0.27 (syst) ± 0.14 (Λ}+_c) MeV/c2 [1], and its lifetime was measured to be 0.256+0.024_−0.022(stat)_{± 0.014 (syst) ps [2].}1 _{The measured lifetime firmly establishes}

its weakly decaying nature. Searching for new decay modes is the next critical step towards understanding the dynamics of weak decays of doubly heavy baryons, which may differ significantly from those of singly heavy hadrons due to interference between decay amplitudes of the two heavy quarks. The process Ξ++

cc → Ξc+π+ has been predicted to

have a sizable branching fraction [3, 4], making it a promising final state in which to seek confirmation of the previous observation.

This Letter reports the first observation of the decay Ξ++

cc → Ξc+π+, which proceeds

predominantly via the tree-level amplitude represented by the Feynman diagram shown in Fig. 1. The Ξ_c+ baryon is reconstructed in its Cabibbo-suppressed decay to pK−π+. The data sample used consists of pp collisions at a center-of-mass energy of 13 TeV collected by the LHCb experiment in 2016, corresponding to an integrated luminosity of 1.7 fb−1. A measurement of the Ξ_cc++ mass with this sample is presented, and the ratio of the total branching fractions, _{R(B), between the decays Ξ}++

cc → Ξc+(→ pK −_π+_{) π}+ _and Ξ++ cc → Λ+c(→ pK−π+) K−π+π+ is determined.

u

c

s

u

¯

d

u

c

c

W

Ξ

Ξ

π

Figure 1: Dominant Feynman diagram contributing to the decay Ξ++

cc → Ξc+π+.

The LHCb detector [5, 6] is a single-arm forward spectrometer covering the pseudora-pidity range 2 < η < 5, designed for the study of particles containing b or c quarks. The detector includes a high-precision tracking system consisting of a silicon-strip vertex detec-tor [7] surrounding the pp interaction region that allows c and b hadrons to be identified from their typical long flight distance; a tracking system [8] that provides a measurement of momentum, p, of charged particles; two ring-imaging Cherenkov detectors [9] that discriminate between different species of charged hadrons; a calorimeter system consisting of scintillating-pad and preshower detectors, an electromagnetic calorimeter and a hadronic calorimeter, to identify photons, electrons and hadrons; a muon system composed of alternating layers of iron and multiwire proportional chambers [10] to identify muons. The online event selection is performed by a trigger [11], which consists of a hardware stage, based on information from the calorimeter and muon systems [12], followed by a

software stage, which applies a full event reconstruction incorporating real-time alignment and calibration of the detector [13]. The same alignment and calibration information is propagated to the offline reconstruction, ensuring consistent and high-quality particle identification (PID) information between the trigger and offline software. The identical performance of the online and offline reconstruction offers the opportunity to perform physics analyses directly using candidates reconstructed in the trigger which is done in the present analysis.

Simulation is required to model the effects of the detector acceptance and the imposed selection requirements. In the simulation, pp collisions are generated using Pythia [14] with a specific LHCb configuration [15]. A dedicated generator, GenXicc2.0 [16], is used to simulate Ξ++

cc baryon production. Decays of hadrons are described by EvtGen [17],

in which final-state radiation is generated using Photos [18]. The interaction of the generated particles with the detector, and its response, are modelled using the Geant4 toolkit [19] as described in Ref. [20].

The selection of Ξ_cc++_{→ Ξc}+(_{→ pK}−π+) π+ decays is designed to be as similar as possible to those of Ξ_cc++ _{→ Λ}+_c(_{→ pK}−π+) K−π+π+, described in Ref. [1]. Three charged particles identified as p, K− and π+ _{that form a good-quality vertex are combined}

to reconstruct a Ξ_c+_{→ pK}−π+ candidate. The three particles are required to have transverse momenta in excess of 500 MeV/c and be inconsistent with originating from any primary vertex (PV). The Ξ+

c vertex is required to be displaced from any PV by a

distance corresponding to a Ξ+

c decay time greater than 0.15 ps, which corresponds to

approximately twice the decay time resolution. The invariant-mass of each Ξ_c+ candidate is required to be in the range 2450–2488 MeV/c2_{, corresponding to approximately six}

times the Ξ+

c mass resolution. An additional positively charged particle, which must

be identified as a pion and have pT greater than 200 MeV/c, is then combined with the

Ξ+

c candidate to form a Ξcc++ candidate. The Ξc+π+ pair is required to form a vertex

that is of good quality and is upstream of the Ξ+

c vertex. The Ξcc++ candidate must

have pT > 2000 MeV/c and be consistent with originating from a PV. The candidate is

associated with the PV with respect to which it has the smallest impact parameter χ2

(χ2

IP). The χ2IP is defined as the difference in χ2 of the PV fit with and without the particle

in question. To avoid contributions due to duplicate tracks, candidates are rejected if the angle between any pair of their final-state particles with the same charge is smaller than 0.5 mrad. Specific hardware trigger requirements are also applied, to increase the signal yield and simplify the study of the trigger efficiency. Candidates are retained only if the event contains large transverse energy deposits in the calorimeter arising from the decay products of the Ξ++

cc candidate, or if the event contains activity either in the calorimeter

or in the muon system from particles other than these decay products. Simulation shows that the efficiency for these additional requirements is above 90% for both two-body or four-body Ξ++

cc decay modes.

A multivariate selector based on the multilayer perceptron algorithm [21] is used to further suppress combinatorial backgrounds. To train the selector, simulated Ξ++

cc → Ξc+(→ pK−π+) π+ decays are used as a signal sample, and 0.3 million

candi-dates from the upper sideband with invariant-masses in the range 3800–4000 MeV/c2 are used as a background sample. To reduce the effect of the Ξ+

c mass resolution on

the invariant-mass of the Ξ++

cc candidates, an alternative evaluation of the

invariant-mass is used, m(Ξ_c+π+)_{≡ M(Ξc}+π+)_{− M([pK}−π+]_Ξ+

c) + MPDG(Ξ

+

c ), where M (Ξc+π+)

and M ([pK−π+_]

Ξc+) are the reconstructed masses of the Ξ

++

MPDG(Ξc+) is the known value of the Ξc+ mass [22].

The input variables used in the multivariate selector are chosen based on their discrimi-nation power between signal and background candidates. Three different types of variables are considered in the training. The first type of variables are the kinematic information of particles, including the pT of each of the four final-state particles and of the Ξc+ and Ξcc++

candidates; the angle between the Ξ_cc++ momentum vector and the displacement vector from the PV to the Ξ++

cc decay vertex. The second type of variables are the vertex fitting

qualities, including the χ2 _{per degree of freedom of the Ξ}+

c and Ξcc++ vertex fits; the χ2

per degree of freedom of a kinematic refit [23] of the Ξ_cc++ _{→ Ξc}+(_{→ pK}−π+) π+ decay chain that requires the Ξ_cc++ to originate from its PV. The third type of variables are related to the lifetime, including the χ2

IP of each of the four final-state particles and of

the Ξ_c+ and Ξ_cc++ candidates with respect to their associated PV; the sum of the χ2_IP of the four final-state particles; and the flight distance χ2 of the Ξ_c+ and Ξ_cc++ candidates. The flight distance χ2 _{is defined as the χ}2 _{of the hypothesis that the decay vertex of the}

candidate coincides with its associated PV.

Candidates are retained only if the multivariate-selector output exceeds a certain threshold. This threshold is chosen to maximize the expected value of the figure of merit ε/(5₂ +√NB) [24]. Here, ε is the estimated signal efficiency and NB is the expected

number of background candidates under the signal peak in the Ξ_cc++ mass distribution, after the selection. The quantity NB is determined, assuming an exponential shape for the

background, from the number of Ξ+

c π+candidates in the mass region of 3800–4000 MeV/c2,

scaled to a signal region centered at a mass of 3620 MeV/c2 and with a width of 30 MeV/c2. This corresponds to approximately five times the expected Ξ++

cc mass resolution. To

test for potential biases in the multivariate selection or other misreconstruction effects, the same selection criteria are applied to control samples of data consisting of Ξ_c+π+ candidates in the Ξ+

c sideband regions and of wrong-sign combination Ξc+π

−_{. No peaking}

structure is visible in either samples.

Figure 2 (left) shows the distribution of invariant-masses of Ξ_cc++candidates, m(Ξ_c+π+), after applying the complete selection. The contribution from events containing multiple signal candidates is found to be less than 1%; all these candidates are included in the fit. A signal is visible at a mass of approximately 3620 MeV/c2, in the vicinity of the previous LHCb Ξ++

cc baryon observation [1]. The mass distribution is fitted with an unbinned

extended maximum-likelihood method to measure the properties of this structure. The peak is described by an empirical model, consisting of a Gaussian function and a modified Gaussian function with power-law tails on both sides [25] and with the same mean value. All tail parameters are fixed to values obtained from a fit to simulated signal events, while the parameters corresponding to the mass and the mass resolution are varied in the fit. The background shape is described by an exponential function. The resulting signal yield is 91_{±20 and the mass value is 3620.7 ± 1.5 MeV/c}2_{, where the uncertainties are statistical}

only. The mass is fully consistent with the value measured in the Ξ_cc++_{→ Λ}+_cK−π+π+ decay channel [1], and the resolution determined by the fit is consistent with expectations based on known detector performance. The local statistical significance of the signal, evaluated by taking the likelihood ratio corresponding to fits that include and exclude the signal component, is found to be 5.9σ, thus confirming the observation reported in Ref [1].

The invariant-mass distribution for the reference mode, Ξ++

cc → Λ+cK−π+π+, is shown

in Fig. 2 (right). The selection used to obtain this sample is identical to that of the previous analysis [1], except for the additional requirements on the hardware trigger. An

3500 3550 3600 3650 3700 0 20 40 60 80 100 Candidates /( 5 Me V /c 2) m(Ξ+ cπ+)  MeV/c2 LHCb _Data Total Signal Background 3500 3550 3600 3650 3700 0 20 40 60 80 100 120 140 160 Candidates /( 5 Me V /c 2) m(Λ+ cK−π+π+)  MeV/c2 LHCb Data Total Signal Background

Figure 2: Invariant-mass distribution of the Ξ++

cc → Ξc+π+(left) and Ξcc++→ Λ+cK−π+π+(right)

candidates with result of the fit overlaid. The black points represent the data, the dotted (red) line represents the signal contribution, and the dashed (green) line represents the combinational background.

extended unbinned maximum-likelihood fit to the invariant-mass distribution returns a signal yield of 289_{± 35 for the reference mode.}

The branching fraction ratio, _{R(B), between the decays Ξ}++

cc → Ξc+(→ pK −_π+_{) π}+ and Ξ++ cc → Λ+c(→ pK −_π+_{) K}−_π+_π+ _{is defined as} R(B) ≡ B (Ξ ++ cc → Ξc+π+)× B (Ξc+ → pK−π+) B (Ξ++ cc → Λ+cK−π+π+)× B (Λ+c → pK−π+) = rN rε , (1)

where rN is the ratio of Ξcc++ yields between the signal and reference decay modes,

and rε is the ratio of total efficiencies between the two modes. In each case, the total

efficiency includes the effects of the geometrical acceptance, trigger, reconstruction, and selection. Each contribution to the efficiency ratio is evaluated with simulation, calibrated with data when possible, as described in the following. The combined efficiency of the reconstruction and the selection, excluding the hardware-trigger requirement, is determined from fully simulated signal samples in which the tracking [26] and particle-identification efficiencies are corrected using control samples. The correction to the efficiency ratio of the Ξ++

cc → Λ+cK

−_π+_π+ _{and Ξ}++

cc → Ξc+π+ channels is determined to be 0.983± 0.007

for the tracking efficiency, and 1.050_{± 0.020 for the particle-identification efficiency. The} hardware-trigger efficiency ratio is estimated from fully simulated signal events, with a pT-dependent correction derived from data using Λ0b → Λ+c(→ pK

−_π+_)π−_π+_π− _and

Λ0

b → Λ+c(→ pK

−_π+_)π− _{decays, which are required to pass the same trigger selection}

as the Ξ_cc++ candidates. These two decay channels have similar final states and decay topologies as the signal. The total relative efficiency is determined to be rε = 0.110±0.002,

where the uncertainty comes from the limited size of the simulation sample and is accounted as a systematic uncertainty. To validate this procedure, the ratio of branching fractions of the decays Λ0

b → Λ+c(→ pK

−_π+_)π− _{and Λ}0

b → Λ+c(→ pK

−_π+_)π−_π+_π− _{is measured using}

the same data sample, resulting in a value 0.83_{±0.05 (statistical uncertainty only) which} agrees with the previous LHCb result of 0.70_{±0.10 [27].}

Ξ++

cc mass are summarized in Table 1. Samples of J/ψ → µ+µ

− _{and B}+ _{→ J/ψ K}+

decays [28, 29] are used to calibrate the reconstructed momentum of charged particles, which affect the reconstructed mass of signal. The maximum difference between the correction factors determined with above-mentioned decays is found to be 0.03%, which corresponds to a systematic uncertainty of 0.38 MeV/c2 _{on the measured Ξ}++

cc mass. The

signal selection efficiency increases with the Ξ_cc++ decay time; combined with a correlation between the reconstructed mass and the reconstructed decay time, this induces a positive bias on the masses of both Ξ++

cc and Ξc+ candidates. The effect is studied with simulation

and the bias on the measured Ξ_cc++ mass is found to be +0.10_{± 0.10 MeV/c}2, where the uncertainty is due to the limited size of the simulated samples. A correction to the Ξ++

cc mass of −0.10 MeV/c2 is therefore applied, and a systematic uncertainty of

0.10 MeV/c2 assigned. The dependence of this bias on the Ξ_cc++ lifetime is studied by weighting simulated events to different lifetime hypotheses; the change is found to be negligible for the measured Ξ++

cc lifetime [2]. The description of the final-state radiation

in simulation [18] can also cause a bias in the measured mass, which is estimated with pseudoexperiments. The correction is determined to be +0.03 MeV/c2, with a negligible uncertainty. The impact of the model used to fit the invariant-mass distribution on the measured mass is estimated by varying the shape parameters that are fixed according to simulation, using alternative signal and background models, and performing the fits over different mass ranges. The largest variation in the fitted Ξ++

cc masses, 0.05 MeV/c2,

is taken as a systematic uncertainty. The current known value for the Ξ+

c mass [22] is

used to compute the invariant-mass m(Ξ_c+π+) of the Ξ_cc++ candidate. Its uncertainty, 0.30 MeV/c2_{, is assigned as a systematic uncertainty on the Ξ}++

cc mass.

The systematic uncertainties on the ratio _{R(B) are listed in Table 1 and are described} as follows. The alternative fit models mentioned above result in different values of the ratio rN. The largest relative deviation measured, 5.2%, is assigned as a systematic

uncertainty on _{R(B). The relative efficiency of the tracking, particle identification and} trigger are estimated using control samples, whose statistical uncertainties are taken as a systematic uncertainty on _{R(B). An additional uncertainty of 4.1% is assigned on} the track-reconstruction efficiency due to uncertainties on the material budget of the detector and the modelling of hadronic interaction with the detector material. The particle-identification efficiency is determined in bins of particle momentum and pseudorapidity using control samples. The size of the bins is increased or decreased by a factor of two and the largest deviation on _{R(B) is assigned as systematic uncertainty related to the} binning. An additional uncertainty of 4.2% on the hardware trigger efficiency is determined from the Λ0

b control samples described above, including a statistical uncertainty from the

limited sample size, and an uncertainty that is determined by testing the procedure in simulation and taking the deviation as a systematic uncertainty. Combining the systematic uncertainties on the efficiency mentioned above, a systematic uncertainty of 6.5% on R(B) is assigned. Uncertainties from the Ξ++

cc mass, lifetime and production spectra are

investigated, and 1.2% is assigned as a systematic uncertainty. Different requirements on the Ξ++

cc pT are applied to select the Ξcc++→ Ξc+π+ and Ξcc++ → Λ+cK−π+π+ decays,

and this may cause a bias if the pT distribution of simulated Ξcc++ differs from that in

data. To assess the size of this effect, the measurement is repeated applying the same pT requirement to both modes. The difference in R(B) is found to be 0.7%. A separate

measurement carried out with a cut-based selection gives a consistent result.

Table 1: Systematic uncertainties on the measurement of the Ξ++

cc mass and of the ratio of

branching fractions_{R(B) between the Ξ}++

cc → Ξc+π+and the Ξcc++→ Λ+cK−π+π+decay modes.

Source Mass [ MeV/c2_{] R(B) [%]}

Momentum calibration 0.38 —

Selection bias correction 0.10 —

Fit model 0.05 5.2 Relative efficiency — 6.5 Simulation modelling — 1.2 Selection — 0.7 Sum in quadrature 0.40 8.5 Ξ++

cc mass is measured to be 3620.6 ± 1.5 (stat) ± 0.4 (syst) ± 0.3 (Ξc+) MeV/c2,

which is consistent with the mass measured in the final state Λ+ cK

−_π+_π+_,

3621.40 _{± 0.72 (stat) ± 0.27 (syst) ± 0.14 (Λ}+_c) MeV/c2 [1]. Averaging over the two mea-surements, the Ξ++

cc mass is determined to be 3621.24± 0.65 (stat) ± 0.31 (syst) MeV/c2

(see the Appendix 1 for the comparisons between the measured Ξ++

cc masses and combined

result). The combination is performed using the Best Linear Unbiased Estimate (BLUE) method [30, 31]. In the combination, the systematic uncertainties are assumed to be uncorrelated except for the momentum scale calibration.

In summary, a new decay mode of the doubly charmed baryon Ξ_cc++_{→ Ξc}+π+ is observed with a statistical significance of 5.9σ in a data sample of pp collisions collected by the LHCb experiment at a center-of-mass energy of √s = 13 TeV. The Ξ++

cc mass is

consistent with the previous LHCb result [1] and with most theoretical calculations of the Ξ++

cc mass (see e.g. Ref. [32]). The ratio of the total branching fractions between

this decay (Ξ++

cc → Ξc+π+) and the reference mode (Ξcc++ → Λ+cK

−_π+_π+_{) is consistent}

with the prediction of Ref. [4], which, however, has large uncertainties. Therefore, this measurement provides important information towards an improved understanding of the decays of doubly charmed baryons.

Acknowledgements

We thank Chao-Hsi Chang, Cai-Dian L¨u, Wei Wang, Xing-Gang Wu, and Fu-Sheng Yu for frequent and interesting discussions on the production and decays of double-heavy-flavor baryons. 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 Sk lodowska-Curie Actions and ERC (European Union); ANR, Labex P2IO and OCEVU, and R´egion Auvergne-Rhˆone-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); Herchel Smith Fund, the Royal Society, the English-Speaking Union and the Leverhulme Trust (United Kingdom); Laboratory Directed Research and Development program of LANL (USA).

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LHCb collaboration

R. Aaij27_{, B. Adeva}41_{, M. Adinolfi}48_{, C.A. Aidala}73_{, Z. Ajaltouni}5_{, S. Akar}59_{, P. Albicocco}18_,

J. Albrecht10_{, F. Alessio}42_{, M. Alexander}53_{, A. Alfonso Albero}40_{, S. Ali}27_{, G. Alkhazov}33_,

P. Alvarez Cartelle55_{, A.A. Alves Jr}41_{, S. Amato}2_{, S. Amerio}23_{, Y. Amhis}7_{, L. An}3_,

L. Anderlini17_{, G. Andreassi}43_{, M. Andreotti}16,g_{, J.E. Andrews}60_{, R.B. Appleby}56_{, F. Archilli}27_,

P. d’Argent12_{, J. Arnau Romeu}6_{, A. Artamonov}39_{, M. Artuso}61_{, K. Arzymatov}37_{, E. Aslanides}6_,

M. Atzeni44_{, B. Audurier}22_{, S. Bachmann}12_{, J.J. Back}50_{, S. Baker}55_{, V. Balagura}7,b_,

W. Baldini16_{, A. Baranov}37_{, R.J. Barlow}56_{, S. Barsuk}7_{, W. Barter}56_{, F. Baryshnikov}70_,

V. Batozskaya31_{, B. Batsukh}61_{, V. Battista}43_{, A. Bay}43_{, J. Beddow}53_{, F. Bedeschi}24_{, I. Bediaga}1_,

A. Beiter61_{, L.J. Bel}27_{, S. Belin}22_{, N. Beliy}63_{, V. Bellee}43_{, N. Belloli}20,i_{, K. Belous}39_,

I. Belyaev34,42_{, E. Ben-Haim}8_{, G. Bencivenni}18_{, S. Benson}27_{, S. Beranek}9_{, A. Berezhnoy}35_,

R. Bernet44_{, D. Berninghoff}12_{, E. Bertholet}8_{, A. Bertolin}23_{, C. Betancourt}44_{, F. Betti}15,42_,

M.O. Bettler49_{, M. van Beuzekom}27_{, Ia. Bezshyiko}44_{, S. Bhasin}48_{, J. Bhom}29_{, S. Bifani}47_,

P. Billoir8_{, A. Birnkraut}10_{, A. Bizzeti}17,u_{, M. Bjørn}57_{, M.P. Blago}42_{, T. Blake}50_{, F. Blanc}43_,

S. Blusk61_{, D. Bobulska}53_{, V. Bocci}26_{, O. Boente Garcia}41_{, T. Boettcher}58_{, A. Bondar}38,w_,

N. Bondar33_{, S. Borghi}56,42_{, M. Borisyak}37_{, M. Borsato}41_{, F. Bossu}7_{, M. Boubdir}9_,

T.J.V. Bowcock54_{, C. Bozzi}16,42_{, S. Braun}12_{, M. Brodski}42_{, J. Brodzicka}29_{, A. Brossa Gonzalo}50_,

D. Brundu22_{, E. Buchanan}48_{, A. Buonaura}44_{, C. Burr}56_{, A. Bursche}22_{, J. Buytaert}42_,

W. Byczynski42_{, S. Cadeddu}22_{, H. Cai}64_{, R. Calabrese}16,g_{, R. Calladine}47_{, M. Calvi}20,i_,

M. Calvo Gomez40,m_{, A. Camboni}40,m_{, P. Campana}18_{, D.H. Campora Perez}42_{, L. Capriotti}56_,

A. Carbone15,e_{, G. Carboni}25_{, R. Cardinale}19,h_{, A. Cardini}22_{, P. Carniti}20,i_{, L. Carson}52_,

K. Carvalho Akiba2_{, G. Casse}54_{, L. Cassina}20_{, M. Cattaneo}42_{, G. Cavallero}19,h_{, R. Cenci}24,p_,

D. Chamont7_{, M.G. Chapman}48_{, M. Charles}8_{, Ph. Charpentier}42_{, G. Chatzikonstantinidis}47_,

M. Chefdeville4_{, V. Chekalina}37_{, C. Chen}3_{, S. Chen}22_{, S.-G. Chitic}42_{, V. Chobanova}41_,

M. Chrzaszcz42_{, A. Chubykin}33_{, P. Ciambrone}18_{, X. Cid Vidal}41_{, G. Ciezarek}42_{, P.E.L. Clarke}52_,

M. Clemencic42_{, H.V. Cliff}49_{, J. Closier}42_{, V. Coco}42_{, J.A.B. Coelho}7_{, J. Cogan}6_{, E. Cogneras}5_,

L. Cojocariu32_{, P. Collins}42_{, T. Colombo}42_{, A. Comerma-Montells}12_{, A. Contu}22_{, G. Coombs}42_,

S. Coquereau40_{, G. Corti}42_{, M. Corvo}16,g_{, C.M. Costa Sobral}50_{, B. Couturier}42_{, G.A. Cowan}52_,

D.C. Craik58_{, A. Crocombe}50_{, M. Cruz Torres}1_{, R. Currie}52_{, C. D’Ambrosio}42_,

F. Da Cunha Marinho2_{, C.L. Da Silva}74_{, E. Dall’Occo}27_{, J. Dalseno}48_{, A. Danilina}34_{, A. Davis}3_,

O. De Aguiar Francisco42_{, K. De Bruyn}42_{, S. De Capua}56_{, M. De Cian}43_{, J.M. De Miranda}1_,

L. De Paula2_{, M. De Serio}14,d_{, P. De Simone}18_{, C.T. Dean}53_{, D. Decamp}4_{, L. Del Buono}8_,

B. Delaney49_{, H.-P. Dembinski}11_{, M. Demmer}10_{, A. Dendek}30_{, D. Derkach}37_{, O. Deschamps}5_,

F. Desse7_{, F. Dettori}54_{, B. Dey}65_{, A. Di Canto}42_{, P. Di Nezza}18_{, S. Didenko}70_{, H. Dijkstra}42_,

F. Dordei42_{, M. Dorigo}42,y_{, A. Dosil Su´arez}41_{, L. Douglas}53_{, A. Dovbnya}45_{, K. Dreimanis}54_,

L. Dufour27_{, G. Dujany}8_{, P. Durante}42_{, J.M. Durham}74_{, D. Dutta}56_{, R. Dzhelyadin}39_,

M. Dziewiecki12_{, A. Dziurda}29_{, A. Dzyuba}33_{, S. Easo}51_{, U. Egede}55_{, V. Egorychev}34_,

S. Eidelman38,w_{, S. Eisenhardt}52_{, U. Eitschberger}10_{, R. Ekelhof}10_{, L. Eklund}53_{, S. Ely}61_,

A. Ene32_{, S. Escher}9_{, S. Esen}27_{, T. Evans}59_{, A. Falabella}15_{, N. Farley}47_{, S. Farry}54_,

D. Fazzini20,42,i_{, L. Federici}25_{, P. Fernandez Declara}42_{, A. Fernandez Prieto}41_{, F. Ferrari}15_,

L. Ferreira Lopes43_{, F. Ferreira Rodrigues}2_{, M. Ferro-Luzzi}42_{, S. Filippov}36_{, R.A. Fini}14_,

M. Fiorini16,g_{, M. Firlej}30_{, C. Fitzpatrick}43_{, T. Fiutowski}30_{, F. Fleuret}7,b_{, M. Fontana}22,42_,

F. Fontanelli19,h_{, R. Forty}42_{, V. Franco Lima}54_{, M. Frank}42_{, C. Frei}42_{, J. Fu}21,q_{, W. Funk}42_,

C. F¨arber42_{, M. F´eo Pereira Rivello Carvalho}27_{, E. Gabriel}52_{, A. Gallas Torreira}41_{, D. Galli}15,e_,

S. Gallorini23_{, S. Gambetta}52_{, Y. Gan}3_{, M. Gandelman}2_{, P. Gandini}21_{, Y. Gao}3_,

L.M. Garcia Martin72_{, B. Garcia Plana}41_{, J. Garc´ıa Pardi˜nas}44_{, J. Garra Tico}49_{, L. Garrido}40_,

D. Gascon40_{, C. Gaspar}42_{, L. Gavardi}10_{, G. Gazzoni}5_{, D. Gerick}12_{, E. Gersabeck}56_,

M. Gersabeck56_{, T. Gershon}50_{, D. Gerstel}6_{, Ph. Ghez}4_{, S. Gian`ı}43_{, V. Gibson}49_{, O.G. Girard}43_,

I.V. Gorelov35_{, C. Gotti}20,i_{, E. Govorkova}27_{, J.P. Grabowski}12_{, R. Graciani Diaz}40_,

L.A. Granado Cardoso42_{, E. Graug´es}40_{, E. Graverini}44_{, G. Graziani}17_{, A. Grecu}32_{, R. Greim}27_,

P. Griffith22_{, L. Grillo}56_{, L. Gruber}42_{, B.R. Gruberg Cazon}57_{, O. Gr¨unberg}67_{, C. Gu}3_,

E. Gushchin36_{, Yu. Guz}39,42_{, T. Gys}42_{, C. G¨obel}62_{, T. Hadavizadeh}57_{, C. Hadjivasiliou}5_,

G. Haefeli43_{, C. Haen}42_{, S.C. Haines}49_{, B. Hamilton}60_{, X. Han}12_{, T.H. Hancock}57_,

S. Hansmann-Menzemer12_{, N. Harnew}57_{, S.T. Harnew}48_{, T. Harrison}54_{, C. Hasse}42_{, M. Hatch}42_,

J. He63_{, M. Hecker}55_{, K. Heinicke}10_{, A. Heister}10_{, K. Hennessy}54_{, L. Henry}72_,

E. van Herwijnen42_{, M. Heß}67_{, A. Hicheur}2_{, R. Hidalgo Charman}56_{, D. Hill}57_{, M. Hilton}56_,

P.H. Hopchev43_{, W. Hu}65_{, W. Huang}63_{, Z.C. Huard}59_{, W. Hulsbergen}27_{, T. Humair}55_,

M. Hushchyn37_{, D. Hutchcroft}54_{, D. Hynds}27_{, P. Ibis}10_{, M. Idzik}30_{, P. Ilten}47_{, K. Ivshin}33_,

R. Jacobsson42_{, J. Jalocha}57_{, E. Jans}27_{, A. Jawahery}60_{, F. Jiang}3_{, M. John}57_{, D. Johnson}42_,

C.R. Jones49_{, C. Joram}42_{, B. Jost}42_{, N. Jurik}57_{, S. Kandybei}45_{, M. Karacson}42_{, J.M. Kariuki}48_,

S. Karodia53_{, N. Kazeev}37_{, M. Kecke}12_{, F. Keizer}49_{, M. Kelsey}61_{, M. Kenzie}49_{, T. Ketel}28_,

E. Khairullin37_{, B. Khanji}12_{, C. Khurewathanakul}43_{, K.E. Kim}61_{, T. Kirn}9_{, S. Klaver}18_,

K. Klimaszewski31_{, T. Klimkovich}11_{, S. Koliiev}46_{, M. Kolpin}12_{, R. Kopecna}12_{, P. Koppenburg}27_,

I. Kostiuk27_{, S. Kotriakhova}33_{, M. Kozeiha}5_{, L. Kravchuk}36_{, M. Kreps}50_{, F. Kress}55_,

P. Krokovny38,w_{, W. Krupa}30_{, W. Krzemien}31_{, W. Kucewicz}29,l_{, M. Kucharczyk}29_,

V. Kudryavtsev38,w_{, A.K. Kuonen}43_{, T. Kvaratskheliya}34,42_{, D. Lacarrere}42_{, G. Lafferty}56_,

A. Lai22_{, D. Lancierini}44_{, G. Lanfranchi}18_{, C. Langenbruch}9_{, T. Latham}50_{, C. Lazzeroni}47_,

R. Le Gac6_{, A. Leflat}35_{, J. Lefran¸cois}7_{, R. Lef`evre}5_{, F. Lemaitre}42_{, O. Leroy}6_{, T. Lesiak}29_,

B. Leverington12_{, P.-R. Li}63_{, T. Li}3_{, Z. Li}61_{, X. Liang}61_{, T. Likhomanenko}69_{, R. Lindner}42_,

F. Lionetto44_{, V. Lisovskyi}7_{, X. Liu}3_{, D. Loh}50_{, A. Loi}22_{, I. Longstaff}53_{, J.H. Lopes}2_,

G.H. Lovell49_{, D. Lucchesi}23,o_{, M. Lucio Martinez}41_{, A. Lupato}23_{, E. Luppi}16,g_{, O. Lupton}42_,

A. Lusiani24_{, X. Lyu}63_{, F. Machefert}7_{, F. Maciuc}32_{, V. Macko}43_{, P. Mackowiak}10_,

S. Maddrell-Mander48_{, O. Maev}33,42_{, K. Maguire}56_{, D. Maisuzenko}33_{, M.W. Majewski}30_,

S. Malde57_{, B. Malecki}29_{, A. Malinin}69_{, T. Maltsev}38,w_{, G. Manca}22,f_{, G. Mancinelli}6_,

D. Marangotto21,q_{, J. Maratas}5,v_{, J.F. Marchand}4_{, U. Marconi}15_{, C. Marin Benito}7_,

M. Marinangeli43_{, P. Marino}43_{, J. Marks}12_{, P.J. Marshall}54_{, G. Martellotti}26_{, M. Martin}6_,

M. Martinelli42_{, D. Martinez Santos}41_{, F. Martinez Vidal}72_{, A. Massafferri}1_{, M. Materok}9_,

R. Matev42_{, A. Mathad}50_{, Z. Mathe}42_{, C. Matteuzzi}20_{, A. Mauri}44_{, E. Maurice}7,b_{, B. Maurin}43_,

A. Mazurov47_{, M. McCann}55,42_{, A. McNab}56_{, R. McNulty}13_{, J.V. Mead}54_{, B. Meadows}59_,

C. Meaux6_{, F. Meier}10_{, N. Meinert}67_{, D. Melnychuk}31_{, M. Merk}27_{, A. Merli}21,q_{, E. Michielin}23_,

D.A. Milanes66_{, E. Millard}50_{, M.-N. Minard}4_{, L. Minzoni}16,g_{, D.S. Mitzel}12_{, A. Mogini}8_,

J. Molina Rodriguez1,z_{, T. Momb¨acher}10_{, I.A. Monroy}66_{, S. Monteil}5_{, M. Morandin}23_,

G. Morello18_{, M.J. Morello}24,t_{, O. Morgunova}69_{, J. Moron}30_{, A.B. Morris}6_{, R. Mountain}61_,

F. Muheim52_{, M. Mulder}27_{, C.H. Murphy}57_{, D. Murray}56_{, A. M¨odden}10_{, D. M¨uller}42_,

J. M¨uller10_{, K. M¨uller}44_{, V. M¨uller}10_{, P. Naik}48_{, T. Nakada}43_{, R. Nandakumar}51_{, A. Nandi}57_,

T. Nanut43_{, I. Nasteva}2_{, M. Needham}52_{, N. Neri}21_{, S. Neubert}12_{, N. Neufeld}42_{, M. Neuner}12_,

T.D. Nguyen43_{, C. Nguyen-Mau}43,n_{, S. Nieswand}9_{, R. Niet}10_{, N. Nikitin}35_{, A. Nogay}69_,

N.S. Nolte42_{, D.P. O’Hanlon}15_{, A. Oblakowska-Mucha}30_{, V. Obraztsov}39_{, S. Ogilvy}18_,

R. Oldeman22,f_{, C.J.G. Onderwater}68_{, A. Ossowska}29_{, J.M. Otalora Goicochea}2_{, P. Owen}44_,

A. Oyanguren72_{, P.R. Pais}43_{, T. Pajero}24,t_{, A. Palano}14_{, M. Palutan}18,42_{, G. Panshin}71_,

A. Papanestis51_{, M. Pappagallo}52_{, L.L. Pappalardo}16,g_{, W. Parker}60_{, C. Parkes}56_,

G. Passaleva17,42_{, A. Pastore}14_{, M. Patel}55_{, C. Patrignani}15,e_{, A. Pearce}42_{, A. Pellegrino}27_,

G. Penso26_{, M. Pepe Altarelli}42_{, S. Perazzini}42_{, D. Pereima}34_{, P. Perret}5_{, L. Pescatore}43_,

K. Petridis48_{, A. Petrolini}19,h_{, A. Petrov}69_{, S. Petrucci}52_{, M. Petruzzo}21,q_{, B. Pietrzyk}4_,

G. Pietrzyk43_{, M. Pikies}29_{, M. Pili}57_{, D. Pinci}26_{, J. Pinzino}42_{, F. Pisani}42_{, A. Piucci}12_,

V. Placinta32_{, S. Playfer}52_{, J. Plews}47_{, M. Plo Casasus}41_{, F. Polci}8_{, M. Poli Lener}18_,

A. Poluektov50_{, N. Polukhina}70,c_{, I. Polyakov}61_{, E. Polycarpo}2_{, G.J. Pomery}48_{, S. Ponce}42_,

C. Prouve48_{, V. Pugatch}46_{, A. Puig Navarro}44_{, H. Pullen}57_{, G. Punzi}24,p_{, W. Qian}63_{, J. Qin}63_,

R. Quagliani8_{, B. Quintana}5_{, B. Rachwal}30_{, J.H. Rademacker}48_{, M. Rama}24_,

M. Ramos Pernas41_{, M.S. Rangel}2_{, F. Ratnikov}37,x_{, G. Raven}28_{, M. Ravonel Salzgeber}42_,

M. Reboud4_{, F. Redi}43_{, S. Reichert}10_{, A.C. dos Reis}1_{, F. Reiss}8_{, C. Remon Alepuz}72_{, Z. Ren}3_,

V. Renaudin7_{, S. Ricciardi}51_{, S. Richards}48_{, K. Rinnert}54_{, P. Robbe}7_{, A. Robert}8_,

A.B. Rodrigues43_{, E. Rodrigues}59_{, J.A. Rodriguez Lopez}66_{, M. Roehrken}42_{, A. Rogozhnikov}37_,

S. Roiser42_{, A. Rollings}57_{, V. Romanovskiy}39_{, A. Romero Vidal}41_{, M. Rotondo}18_,

M.S. Rudolph61_{, T. Ruf}42_{, J. Ruiz Vidal}72_{, J.J. Saborido Silva}41_{, N. Sagidova}33_{, B. Saitta}22,f_,

V. Salustino Guimaraes62_{, C. Sanchez Gras}27_{, C. Sanchez Mayordomo}72_{, B. Sanmartin Sedes}41_,

R. Santacesaria26_{, C. Santamarina Rios}41_{, M. Santimaria}18_{, E. Santovetti}25,j_{, G. Sarpis}56_,

A. Sarti18,k_{, C. Satriano}26,s_{, A. Satta}25_{, M. Saur}63_{, D. Savrina}34,35_{, S. Schael}9_,

M. Schellenberg10_{, M. Schiller}53_{, H. Schindler}42_{, M. Schmelling}11_{, T. Schmelzer}10_{, B. Schmidt}42_,

O. Schneider43_{, A. Schopper}42_{, H.F. Schreiner}59_{, M. Schubiger}43_{, M.H. Schune}7_,

R. Schwemmer42_{, B. Sciascia}18_{, A. Sciubba}26,k_{, A. Semennikov}34_{, E.S. Sepulveda}8_{, A. Sergi}47,42_,

N. Serra44_{, J. Serrano}6_{, L. Sestini}23_{, A. Seuthe}10_{, P. Seyfert}42_{, M. Shapkin}39_{, Y. Shcheglov}33,†_,

T. Shears54_{, L. Shekhtman}38,w_{, V. Shevchenko}69_{, E. Shmanin}70_{, B.G. Siddi}16_,

R. Silva Coutinho44_{, L. Silva de Oliveira}2_{, G. Simi}23,o_{, S. Simone}14,d_{, N. Skidmore}12_,

T. Skwarnicki61_{, J.G. Smeaton}49_{, E. Smith}9_{, I.T. Smith}52_{, M. Smith}55_{, M. Soares}15_,

l. Soares Lavra1_{, M.D. Sokoloff}59_{, F.J.P. Soler}53_{, B. Souza De Paula}2_{, B. Spaan}10_{, P. Spradlin}53_,

F. Stagni42_{, M. Stahl}12_{, S. Stahl}42_{, P. Stefko}43_{, S. Stefkova}55_{, O. Steinkamp}44_{, S. Stemmle}12_,

O. Stenyakin39_{, M. Stepanova}33_{, H. Stevens}10_{, A. Stocchi}7_{, S. Stone}61_{, B. Storaci}44_,

S. Stracka24,p_{, M.E. Stramaglia}43_{, M. Straticiuc}32_{, U. Straumann}44_{, S. Strokov}71_{, J. Sun}3_,

L. Sun64_{, K. Swientek}30_{, V. Syropoulos}28_{, T. Szumlak}30_{, M. Szymanski}63_{, S. T’Jampens}4_,

Z. Tang3_{, A. Tayduganov}6_{, T. Tekampe}10_{, G. Tellarini}16_{, F. Teubert}42_{, E. Thomas}42_,

J. van Tilburg27_{, M.J. Tilley}55_{, V. Tisserand}5_{, M. Tobin}30_{, S. Tolk}42_{, L. Tomassetti}16,g_,

D. Tonelli24_{, D.Y. Tou}8_{, R. Tourinho Jadallah Aoude}1_{, E. Tournefier}4_{, M. Traill}53_{, M.T. Tran}43_,

A. Trisovic49_{, A. Tsaregorodtsev}6_{, G. Tuci}24_{, A. Tully}49_{, N. Tuning}27,42_{, A. Ukleja}31_,

A. Usachov7_{, A. Ustyuzhanin}37_{, U. Uwer}12_{, A. Vagner}71_{, V. Vagnoni}15_{, A. Valassi}42_{, S. Valat}42_,

G. Valenti15_{, R. Vazquez Gomez}42_{, P. Vazquez Regueiro}41_{, S. Vecchi}16_{, M. van Veghel}27_,

J.J. Velthuis48_{, M. Veltri}17,r_{, G. Veneziano}57_{, A. Venkateswaran}61_{, T.A. Verlage}9_{, M. Vernet}5_,

M. Veronesi27_{, N.V. Veronika}13_{, M. Vesterinen}57_{, J.V. Viana Barbosa}42_{, D. Vieira}63_,

M. Vieites Diaz41_{, H. Viemann}67_{, X. Vilasis-Cardona}40,m_{, A. Vitkovskiy}27_{, M. Vitti}49_,

V. Volkov35_{, A. Vollhardt}44_{, B. Voneki}42_{, A. Vorobyev}33_{, V. Vorobyev}38,w_{, J.A. de Vries}27_,

C. V´azquez Sierra27_{, R. Waldi}67_{, J. Walsh}24_{, J. Wang}61_{, M. Wang}3_{, Y. Wang}65_{, Z. Wang}44_,

D.R. Ward49_{, H.M. Wark}54_{, N.K. Watson}47_{, D. Websdale}55_{, A. Weiden}44_{, C. Weisser}58_,

M. Whitehead9_{, J. Wicht}50_{, G. Wilkinson}57_{, M. Wilkinson}61_{, I. Williams}49_{, M.R.J. Williams}56_,

M. Williams58_{, T. Williams}47_{, F.F. Wilson}51,42_{, J. Wimberley}60_{, M. Winn}7_{, J. Wishahi}10_,

W. Wislicki31_{, M. Witek}29_{, G. Wormser}7_{, S.A. Wotton}49_{, K. Wyllie}42_{, D. Xiao}65_{, Y. Xie}65_,

A. Xu3_{, 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. Yin65_{, J. Yu}65,ab_{, X. Yuan}61_{, O. Yushchenko}39_{, K.A. Zarebski}47_{, M. Zavertyaev}11,c_,

D. Zhang65_{, L. Zhang}3_{, W.C. Zhang}3,aa_{, Y. Zhang}7_{, A. Zhelezov}12_{, Y. Zheng}63_{, X. Zhu}3_,

V. Zhukov9,35_{, J.B. Zonneveld}52_{, S. Zucchelli}15_.

1_{Centro Brasileiro de Pesquisas F´ısicas (CBPF), Rio de Janeiro, Brazil} 2_{Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil} 3_{Center for High Energy Physics, Tsinghua University, Beijing, China}

4_{Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IN2P3-LAPP, Annecy, France} 5_{Clermont Universit´e, Universit´e Blaise Pascal, CNRS/IN2P3, LPC, Clermont-Ferrand, France} 6_{Aix Marseille Univ, CNRS/IN2P3, CPPM, Marseille, France}

7_{LAL, Univ. Paris-Sud, CNRS/IN2P3, Universit´e Paris-Saclay, Orsay, France}

9_{I. Physikalisches Institut, RWTH Aachen University, Aachen, Germany} 10_{Fakult¨at Physik, Technische Universit¨at Dortmund, Dortmund, Germany} 11_{Max-Planck-Institut f¨ur Kernphysik (MPIK), Heidelberg, Germany}

12_{Physikalisches Institut, Ruprecht-Karls-Universit¨at Heidelberg, Heidelberg, Germany} 13_{School of Physics, University College Dublin, Dublin, Ireland}

14_{INFN Sezione di Bari, Bari, Italy} 15_{INFN Sezione di Bologna, Bologna, Italy} 16_{INFN Sezione di Ferrara, Ferrara, Italy} 17_{INFN Sezione di Firenze, Firenze, Italy}

18_{INFN Laboratori Nazionali di Frascati, Frascati, Italy} 19_{INFN Sezione di Genova, Genova, Italy}

20_{INFN Sezione di Milano-Bicocca, Milano, Italy} 21_{INFN Sezione di Milano, Milano, Italy}

22_{INFN Sezione di Cagliari, Monserrato, Italy} 23_{INFN Sezione di Padova, Padova, Italy} 24_{INFN Sezione di Pisa, Pisa, Italy}

25_{INFN Sezione di Roma Tor Vergata, Roma, Italy} 26_{INFN Sezione di Roma La Sapienza, Roma, Italy}

27_{Nikhef National Institute for Subatomic Physics, Amsterdam, Netherlands}

28_{Nikhef National Institute for Subatomic Physics and VU University Amsterdam, Amsterdam,} Netherlands

29_{Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences, Krak´ow, Poland} 30_{AGH - University of Science and Technology, Faculty of Physics and Applied Computer Science,} Krak´ow, Poland

31_{National Center for Nuclear Research (NCBJ), Warsaw, Poland}

32_{Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest-Magurele, Romania} 33_{Petersburg Nuclear Physics Institute (PNPI), Gatchina, Russia}

34_{Institute of Theoretical and Experimental Physics (ITEP), Moscow, Russia}

35_{Institute of Nuclear Physics, Moscow State University (SINP MSU), Moscow, Russia}

36_{Institute for Nuclear Research of the Russian Academy of Sciences (INR RAS), Moscow, Russia} 37_{Yandex School of Data Analysis, Moscow, Russia}

38_{Budker Institute of Nuclear Physics (SB RAS), Novosibirsk, Russia} 39_{Institute for High Energy Physics (IHEP), Protvino, Russia}

40_{ICCUB, Universitat de Barcelona, Barcelona, Spain}

41_{Instituto Galego de F´ısica de Altas Enerx´ıas (IGFAE), Universidade de Santiago de Compostela,} Santiago de Compostela, Spain

42_{European Organization for Nuclear Research (CERN), Geneva, Switzerland}

43_{Institute of Physics, Ecole Polytechnique F´ed´erale de Lausanne (EPFL), Lausanne, Switzerland} 44_{Physik-Institut, Universit¨at Z¨urich, Z¨urich, Switzerland}

45_{NSC Kharkiv Institute of Physics and Technology (NSC KIPT), Kharkiv, Ukraine}

46_{Institute for Nuclear Research of the National Academy of Sciences (KINR), Kyiv, Ukraine} 47_{University of Birmingham, Birmingham, United Kingdom}

48_{H.H. Wills Physics Laboratory, University of Bristol, Bristol, United Kingdom} 49_{Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom} 50_{Department of Physics, University of Warwick, Coventry, United Kingdom} 51_{STFC Rutherford Appleton Laboratory, Didcot, United Kingdom}

52_{School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom} 53_{School of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom} 54_{Oliver Lodge Laboratory, University of Liverpool, Liverpool, United Kingdom} 55_{Imperial College London, London, United Kingdom}

56_{School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom} 57_{Department of Physics, University of Oxford, Oxford, United Kingdom}

58_{Massachusetts Institute of Technology, Cambridge, MA, United States} 59_{University of Cincinnati, Cincinnati, OH, United States}

60_{University of Maryland, College Park, MD, United States} 61_{Syracuse University, Syracuse, NY, United States}

62_{Pontif´ıcia Universidade Cat´olica do Rio de Janeiro (PUC-Rio), Rio de Janeiro, Brazil, associated to} 2 63_{University of Chinese Academy of Sciences, Beijing, China, associated to}3

64_{School of Physics and Technology, Wuhan University, Wuhan, China, associated to}3

65_{Institute of Particle Physics, Central China Normal University, Wuhan, Hubei, China, associated to}3 66_{Departamento de Fisica , Universidad Nacional de Colombia, Bogota, Colombia, associated to}8 67_{Institut f¨ur Physik, Universit¨at Rostock, Rostock, Germany, associated to} 12

68_{Van Swinderen Institute, University of Groningen, Groningen, Netherlands, associated to}27 69_{National Research Centre Kurchatov Institute, Moscow, Russia, associated to}34

70_{National University of Science and Technology ”MISIS”, Moscow, Russia, associated to} 34 71_{National Research Tomsk Polytechnic University, Tomsk, Russia, associated to} 34

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

73_{University of Michigan, Ann Arbor, United States, associated to} 61

74_{Los Alamos National Laboratory (LANL), Los Alamos, United States, associated to} 61

a_{Universidade Federal do Triˆangulo Mineiro (UFTM), Uberaba-MG, Brazil} b_{Laboratoire Leprince-Ringuet, Palaiseau, France}

c_{P.N. Lebedev Physical Institute, Russian Academy of Science (LPI RAS), Moscow, Russia} d_{Universit`a di Bari, Bari, Italy}

e_{Universit`a di Bologna, Bologna, Italy</sub> f<sub>Universit`a di Cagliari, Cagliari, Italy} g_{Universit`a di Ferrara, Ferrara, Italy</sub> h<sub>Universit`a di Genova, Genova, Italy} i_{Universit`a di Milano Bicocca, Milano, Italy</sub> j<sub>Universit`a di Roma Tor Vergata, Roma, Italy} k_{Universit`a di Roma La Sapienza, Roma, Italy}

l_{AGH - University of Science and Technology, Faculty of Computer Science, Electronics and} Telecommunications, Krak´ow, Poland

m_{LIFAELS, La Salle, Universitat Ramon Llull, Barcelona, Spain} n_{Hanoi University of Science, Hanoi, Vietnam}

o_{Universit`a di Padova, Padova, Italy</sub> p<sub>Universit`a di Pisa, Pisa, Italy}

q_{Universit`a degli Studi di Milano, Milano, Italy</sub> r<sub>Universit`a di Urbino, Urbino, Italy}

s_{Universit`a della Basilicata, Potenza, Italy} t_{Scuola Normale Superiore, Pisa, Italy}

u_{Universit`a di Modena e Reggio Emilia, Modena, Italy}

v_{MSU - Iligan Institute of Technology (MSU-IIT), Iligan, Philippines} w_{Novosibirsk State University, Novosibirsk, Russia}

x_{National Research University Higher School of Economics, Moscow, Russia} y_{Sezione INFN di Trieste, Trieste, Italy}

z_{Escuela Agr´ıcola Panamericana, San Antonio de Oriente, Honduras}

aa_{School of Physics and Information Technology, Shaanxi Normal University (SNNU), Xi’an, China} ab_{Physics and Micro Electronic College, Hunan University, Changsha City, China}

1

Supplementary material for

LHCb-PAPER-2018-026

Figure 3 shows the comparison between Ξ_cc++ mass measured from Ξ_cc++_{→ Λ}+_cK−π+π+ and Ξ++

cc → Ξc+π+ channel, and the combined mass value using these two results.

3618 3620 3622 3624 3618 3620 3622 3624

M(Ξ

)



MeV/c



LHCb

Ξ

→ Λ

K

π

π

Ξ

→ Ξ

π

Combined

cc masses obtained with the decay modes Ξcc++ → Λ+cK−π+π+ and

Ξ++

cc → Ξc+π+, and the combined result. The darker green band represents the statistical

uncertainty on the combination, and the lighter green band represents the total uncertainty on the combination.