@article{e737ed99b9374f4490077e36f2ca6cd4,

title = "Measurement of the branching ratio Γ(Λb 0→ψ(2S)Λ0)/Γ(Λb 0→J/ψΛ0) with the ATLAS detector",

abstract = "An observation of the Λb 0→ψ(2S)Λ0 decay and a comparison of its branching fraction with that of the Λb 0→J/ψΛ0 decay has been made with the ATLAS detector in proton–proton collisions at s=8 TeV at the LHC using an integrated luminosity of 20.6 fb−1. The J/ψ and ψ(2S) mesons are reconstructed in their decays to a muon pair, while the Λ0→pπ− decay is exploited for the Λ0 baryon reconstruction. The Λb 0 baryons are reconstructed with transverse momentum pT>10 GeV and pseudorapidity |η|<2.1. The measured branching ratio of the Λb 0→ψ(2S)Λ0 and Λb 0→J/ψΛ0 decays is Γ(Λb 0→ψ(2S)Λ0)/Γ(Λb 0→J/ψΛ0)=0.501±0.033(stat)±0.019(syst), lower than the expectation from the covariant quark model.",

author = "{ATLAS Collaboration} and G. Aad and B. Abbott and J. Abdallah and O. Abdinov and R. Aben and M. Abolins and AbouZeid, {O. S.} and H. Abramowicz and H. Abreu and R. Abreu and Y. Abulaiti and Acharya, {B. S.} and L. Adamczyk and Adams, {D. L.} and J. Adelman and S. Adomeit and T. Adye and Affolder, {A. A.} and T. Agatonovic-Jovin and J. Agricola and Aguilar-Saavedra, {J. A.} and Ahlen, {S. P.} and F. Ahmadov and G. Aielli and H. Akerstedt and {\AA}kesson, {T. P.A.} and Akimov, {A. V.} and Alberghi, {G. L.} and J. Albert and S. Albrand and {Alconada Verzini}, {M. J.} and M. Aleksa and Aleksandrov, {I. N.} and C. Alexa and G. Alexander and T. Alexopoulos and M. Alhroob and G. Alimonti and L. Alio and J. Alison and Alkire, {S. P.} and Allbrooke, {B. M.M.} and Allport, {P. P.} and A. Aloisio and A. Alonso and F. Alonso and C. Alpigiani and A. Altheimer and {Alvarez Gonzalez}, B. and {{\'A}lvarez Piqueras}, D. and Alviggi, {M. G.} and Amadio, {B. T.} and K. Amako and {Amaral Coutinho}, Y. and C. Amelung and D. Amidei and {Amor Dos Santos}, {S. P.} and A. Amorim and S. Amoroso and N. Amram and G. Amundsen and C. Anastopoulos and Ancu, {L. S.} and N. Andari and T. Andeen and Anders, {C. F.} and G. Anders and Anders, {J. K.} and Anderson, {K. J.} and A. Andreazza and V. Andrei and S. Angelidakis and I. Angelozzi and P. Anger and A. Angerami and F. Anghinolfi and Anisenkov, {A. V.} and N. Anjos and A. Annovi and M. Antonelli and A. Antonov and J. Antos and F. Anulli and M. Aoki and {Aperio Bella}, L. and G. Arabidze and Y. Arai and Araque, {J. P.} and Arce, {A. T.H.} and Arduh, {F. A.} and Arguin, {J. F.} and S. Argyropoulos and M. Arik and Armbruster, {A. J.} and O. Arnaez and V. Arnal and H. Arnold and M. Arratia and O. Arslan and A. Artamonov and G. Artoni and S. Asai and N. Asbah and A. Ashkenazi and B. {\AA}sman and L. Asquith and K. Assamagan and R. Astalos and M. Atkinson and Atlay, {N. B.} and K. Augsten and M. Aurousseau and G. Avolio and B. Axen and Ayoub, {M. K.} and G. Azuelos and Baak, {M. A.} and Baas, {A. E.} and Baca, {M. J.} and C. Bacci and H. Bachacou and K. Bachas and M. Backes and M. Backhaus and P. Bagiacchi and P. Bagnaia and Y. Bai and T. Bain and Baines, {J. T.} and Baker, {O. K.} and Baldin, {E. M.} and P. Balek and T. Balestri and F. Balli and E. Banas and Sw Banerjee and Bannoura, {A. A.E.} and Bansil, {H. S.} and L. Barak and Barberio, {E. L.} and D. Barberis and M. Barbero and T. Barillari and M. Barisonzi and T. Barklow and N. Barlow and Barnes, {S. L.} and Barnett, {B. M.} and Barnett, {R. M.} and Z. Barnovska and A. Baroncelli and G. Barone and Barr, {A. J.} and F. Barreiro and {Barreiro Guimar{\~a}es da Costa}, J. and R. Bartoldus and Barton, {A. E.} and P. Bartos and A. Basalaev and A. Bassalat and A. Basye and Bates, {R. L.} and Batista, {S. J.} and Batley, {J. R.} and M. Battaglia and M. Bauce and F. Bauer and Bawa, {H. S.} and Beacham, {J. B.} and Beattie, {M. D.} and T. Beau and Beauchemin, {P. H.} and R. Beccherle and P. Bechtle and Beck, {H. P.} and K. Becker and M. Becker and S. Becker and M. Beckingham and C. Becot and Beddall, {A. J.} and A. Beddall and Bednyakov, {V. A.} and Bee, {C. P.} and Beemster, {L. J.} and Beermann, {T. A.} and M. Begel and Behr, {J. K.} and C. Belanger-Champagne and Bell, {W. H.} and G. Bella and L. Bellagamba and A. Bellerive and M. Bellomo and K. Belotskiy and O. Beltramello and O. Benary and D. Benchekroun and M. Bender and X. Zhao",

note = "Publisher Copyright: {\textcopyright} 2015 CERN for the benefit of the ATLAS Collaboration",

year = "2015",

month = dec,

day = "17",

doi = "10.1016/j.physletb.2015.10.009",

language = "English",

volume = "751",

pages = "63--80",

journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",

issn = "0370-2693",

}