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arXiv · 1306.2577

Measurement of the differential branching fraction of the decay $Λ_b^0\rightarrowΛμ^+μ^-$

LHCb collaboration·R. Aaij·B. Adeva·M. Adinolfi·C. Adrover·A. Affolder·Z. Ajaltouni·J. Albrecht·F. Alessio·M. Alexander·S. Ali·G. Alkhazov·P. Alvarez Cartelle·A. A. Alves Jr·S. Amato·S. Amerio·Y. Amhis·L. Anderlini·J. Anderson·R. Andreassen·J. E. Andrews·R. B. Appleby·O. Aquines Gutierrez·F. Archilli·A. Artamonov·M. Artuso·E. Aslanides·G. Auriemma·M. Baalouch·S. Bachmann·J. J. Back·C. Baesso·V. Balagura·W. Baldini·R. J. Barlow·C. Barschel·S. Barsuk·W. Barter·Th. Bauer·A. Bay·J. Beddow·F. Bedeschi·I. Bediaga·S. Belogurov·K. Belous·I. Belyaev·E. Ben-Haim·G. Bencivenni·S. Benson·J. Benton·A. Berezhnoy·R. Bernet·M. -O. Bettler·M. van Beuzekom·A. Bien·S. Bifani·T. Bird·A. Bizzeti·P. M. Bjørnstad·T. Blake·F. Blanc·J. Blouw·S. Blusk·V. Bocci·A. Bondar·N. Bondar·W. Bonivento·S. Borghi·A. Borgia·T. J. V. Bowcock·E. Bowen·C. Bozzi·T. Brambach·J. van den Brand·J. Bressieux·D. Brett·M. Britsch·T. Britton·N. H. Brook·H. Brown·I. Burducea·A. Bursche·G. Busetto·J. Buytaert·S. Cadeddu·O. Callot·M. Calvi·M. Calvo Gomez·A. Camboni·P. Campana·D. Campora Perez·A. Carbone·G. Carboni·R. Cardinale·A. Cardini·H. Carranza-Mejia·L. Carson·K. Carvalho Akiba·G. Casse·L. Castillo Garcia
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Abstract

The differential branching fraction of the decay $Λ_b^0\rightarrowΛμ^+μ^-$ is measured as a function of the square of the dimuon invariant mass, $q^2$. A yield of $78\pm12$ $Λ_b^0\rightarrowΛμ^+μ^-$ decays is observed using data, corresponding to an integrated luminosity of 1.0\,fb$^{-1}$, collected by the LHCb experiment at a centre-of-mass energy of 7\,TeV. A significant signal is found in the $q^2$ region above the square of the $J/ψ$ mass, while at lower-$q^2$ values upper limits are set on the differential branching fraction. Integrating the differential branching fraction over $q^2$, while excluding the $J/ψ$ and $ψ(2S)$ regions, gives a branching fraction of $\BF($Λ_b^0\rightarrowΛμ^+μ^-$)=(0.96\pm 0.16\stat\pm 0.13\syst\pm 0.21 (\mathrm{norm}))\times 10^{-6}$, where the uncertainties are statistical, systematic and due to the normalisation mode, $$Λ_b^0\rightarrow J/psiΛ$, respectively.

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LHCb collaboration, R. Aaij, B. Adeva, M. Adinolfi, C. Adrover, A. Affolder, Z. Ajaltouni, J. Albrecht, F. Alessio, M. Alexander, S. Ali, G. Alkhazov, P. Alvarez Cartelle, A. A. Alves Jr, S. Amato, S. Amerio, Y. Amhis, L. Anderlini, J. Anderson, R. Andreassen, J. E. Andrews, R. B. Appleby, O. Aquines Gutierrez, F. Archilli, A. Artamonov, M. Artuso, E. Aslanides, G. Auriemma, M. Baalouch, S. Bachmann, J. J. Back, C. Baesso, V. Balagura, W. Baldini, R. J. Barlow, C. Barschel, S. Barsuk, W. Barter, Th. Bauer, A. Bay, J. Beddow, F. Bedeschi, I. Bediaga, S. Belogurov, K. Belous, I. Belyaev, E. Ben-Haim, G. Bencivenni, S. Benson, J. Benton, A. Berezhnoy, R. Bernet, M. -O. Bettler, M. van Beuzekom, A. Bien, S. Bifani, T. Bird, A. Bizzeti, P. M. Bjørnstad, T. Blake, F. Blanc, J. Blouw, S. Blusk, V. Bocci, A. Bondar, N. Bondar, W. Bonivento, S. Borghi, A. Borgia, T. J. V. Bowcock, E. Bowen, C. Bozzi, T. Brambach, J. van den Brand, J. Bressieux, D. Brett, M. Britsch, T. Britton, N. H. Brook, H. Brown, I. Burducea, A. Bursche, G. Busetto, J. Buytaert, S. Cadeddu, O. Callot, M. Calvi, M. Calvo Gomez, A. Camboni, P. Campana, D. Campora Perez, A. Carbone, G. Carboni, R. Cardinale, A. Cardini, H. Carranza-Mejia, L. Carson, K. Carvalho Akiba, G. Casse, L. Castillo Garcia. 2013-06-11. Measurement of the differential branching fraction of the decay $Λ_b^0\rightarrowΛμ^+μ^-$. https://doi.org/10.1016/j.physletb.2013.06.060

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