Search for the doubly heavy baryons Ω^(0)_(bc) and E^(0)_(bc) decaying to Λ^(+)_(c)π^(-) and E^(+)_(c)π^(-)  

作　　者：R.Aaij C.Abelian Beteta T.Ackernley B.Adeva M.Adinolfi H.Afshamia C.A.Aidala S.Aiola Z.Ajaltouni S.Aka J.Albrecht F.Alessio M.Alexander A.Alfonso Albero Z.Aliouche G.Alkhazov P.Alvarez Cartelie S.Amato Y.Amhis L.An L.Anderlini A.Andreianov M.Andreotti F.Archilli A.Artamonov M.Artuso K.Arzymatov E.Aslanides M.Atzeni B.Audurier S.Bachmann M.Bachmayer J.J.Back P.Baladron Rodriguez V.Balagura W.Baldini J.Baptista Leite R.J.Barlow S.Barsuk W.Barter M.Bartolini F.Baryshnikov J.M.Basels G.Bassi B.Batsukh A.Battig A.Bay M.Becker F.Bedeschi I.Bediaga A.Beiter V.Belavin S.Belin V.Bellee K.Belous I.Belov I.Belyaev G.Bencivenni E.Ben-Haim A.Berezhnoy R.Bernet D.Beminghoff H.C.Bernstein C.Bertella A.Bertolin C.Betancourt F.Betti Ia.Bezshyiko S.Bhasin J.Bhom L.Bian M.S.Bieker S.Bifani P.Billoir M.Birch F.C.R.Bishop A.Bitadze A.Bizzeti M.Bjorn M.P.Blago T.Blake F.Blanc S.Blusk D.Bobulska J.A.Boelhauve O.Boente Garcia T.Boettcher A.Boldyrev A.Bondar N.Bondar S.Borghi M.Borisyak M.Borsato J.T.Borsuk S.A.Bouchiba T.J.V.Bowcock A.Boyer C.Bozzi M J.Bradley S.Braun A.Brea Rodriguez M.Brodski J.Brodzicka A.Brossa Gonzalo D.Brundu A.Buonaura C.Burr A.Bursche A.Butkevich J.S.Butter J.Buytaert W.Byczynski S.Cadeddu H.Cai R.Calabrese L.Calefice L.Calero Diaz S.Cali R.Calladine M.Calvi M.Calvo Gomez P.Camargo Magalhaes A.Camboni P.Campana A.F.Campoverde Quezada S.Capelli L.Capriotti A.Carbone G.Carboni R.Cardinale A.Cardini I.Carli P.Camiti L.Carus K.Carvalho Akiba A.Casais Vidal G.C 

机构地区：[1]Centro Brasileiro de Pesquisas Fisicas(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]Institute of High Energy Physics(IHEP),Beijing,China [5]School of Physics State Key Laboratory of Nuclear Physics and Technology,Peking University,Beijing,China [6]University ofChinese Academy of Sciences,Beijing,China [7]Institute of Particle Physics,Central China Normal University,Wuhan,Hubei,China [8]Univ.Savoie Mont Blanc,CNRS,IN2P3-LAPP,Annecy,France [9]Universite Clermont Auvergne,CNRS/IN2P3,LPC,Clermont-Ferrand,France [10]Aix Marseille Univ,CNRS/IN2P3,CPPM,Marseille,France [11]Universite Paris-Saclay,CNRS/IN2P3,IJCLab,Orsay,France [12]Laboratoire Leprince-Ringuet,CNRS/IN2P3,Ecole Polytechnique,Institut Polytechnique de Paris,Palaiseau,France [13]LPNHE,Sorbonne Universite,Paris Diderot Sorbonne Paris Cite,CNRS/FN2P3,Paris,France [14]I.Physikalisches Institut,RWTH Aachen University,Aachen,Germany [15]Fakultat Physik,Technische Universitat Dortmund,Dortmund,Germany [16]Max-Planck-Institut für Kemphysik(MPIK),Heidelberg,Germany [17]Physikalisches Institut,Ruprecht-Karls-Universitat Heidelberg,Heidelberg,Germany [18]School of Physics,University College Dublin,Dublin,Ireland [19]INFN Sezione di Bari,Bari,Italy [20]INFN Sezione di Bologna,Bologna,Italy [21]INFN Sezione di Ferrara,Ferrara,Italy [22]INFN Sezione di Firenze,Firenze,Italy [23]INFN Laboratori Nazionali di Frascati,Frascati,Italy [24]INFN Sezione di Genova,Genova,Italy [25]INFN Sezione di Milano,Milano,Italy [26]INFN Sezione di Milano-Bicocca,Milano,Italy [27]INFN Sezione di Cagliari,Monserrato,Italy [28]Universita degli Studi di Padova,Universita e INFN,Padova,Padova,Italy [29]INFN Sezione di Pisa,Pisa,Italy [30]INFN Sezione di Roma La Sapienza,Roma,Italy [31]INFN Sezione di Roma Tor Vergata,Roma,Italy [32]Nikhef National Institute for Subatomic Physics,Amsterdam,Netherlands [33]Nikhef National Institute for Subatomic Physics and VU University

出　　处：《Chinese Physics C》2021年第9期10-21,共12页中国物理C（英文版）

基　　金：CAPES,CNPq,FAPERJ and FINEP(Brazil);MOST and NSFC(China);CNRS/IN2P3(France);BMBF,DFG,MPG(Germany);INFN(Italy);NWO(Netherlands);MNiSW,NCN(Poland);MEN/IFA(Romania);MSHE(Russia);MICINN(Spain);SNSF,SER(Switzerland);NASU(Ukraine);STFC(United Kingdom);DOE NP,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 NERSC(USA);AvH Foundation(Germany);EPLANET,Marie Sklodowska-Curie Actions and ERC(European Union);A*MIDEX,ANR,Labex P2IO and OCEVU,Region Auvergne-Rhdne-Alpes(France);Key Research Program of Frontier Sciences of CAS,CAS PIFI,CAS CCEPP,Fundamental Research Funds for the Central Universities,and Sci.Tech.Program of Guangzhou(China);RFBR,RSF and Yandex LLC(Russia);GVA,XuntaGal,GENCAT(Spain);the Leverhulme Trust,the Royal Society and UKRI(United Kingdom)。

摘　　要：The first search for the doubly heavyΩ^(0)_(bc)baryon and a search for the E^(0)_(bc)baryon are performed using pp collision data collected via the LHCb experiment from 2016 to 2018 at a centre-of-mass energy of 13 TeV,corresponding to an integrated luminosity of 5.2 fb^(-1).The baryons are reconstructed via their decays to Λ^(+)_(c)π^(-)and E^(+)_(c)π^(-).No significant excess is fbund for invariant masses between 6700 and 7300 MeV/c^(2),in a rapidity range from 2.0 to 4.5 and a transverse momentum range from 2 to 20 MeV/c.Upper limits are set on the ratio of the Ω^(0)_(bc)and E^(0)_(bc)production cross-section times the branching fraction to Λ^(+)_(c)π^(-)(E^(+)_(c)π^(-))relative to that of the Λ^(0)_(b)(E^(0)_(b))baryon,for different lifetime hypotheses,at 95%confidence level.The upper limits range from 0.5 x 10^(-4)to 2.5 x 10^(-4)for theΩ^(0)_(bc)→Λ^(+)_(c)π^(-)(E^(0)_(bc)→Λ^(+)_(c)π^(-))decay,and from 1.4x 10^(-3)to 6.9 x 10^(-3)for theΩ^(0)_(bc)→E^(+)_(c)π^(-)(E^(0)_(bc)→E^(+)_(c)π^(-))decay,depending on the considered mass and lifetime of theΩ^(0)_(bc)(E^(0)_(bc))baryon.

关 键 词：B physics QUARKONIUM SPECTROSCOPY heavy quark production 

分 类 号：O572.3[理学—粒子物理与原子核物理]