@article{10902/2153, year = {2011}, month = {11}, url = {http://hdl.handle.net/10902/2153}, abstract = {We report the first observation of the baryonic flavor-changing neutral current decay Λb0→Λμ+μ- with 24 signal events and a statistical significance of 5.8 Gaussian standard deviations. This measurement uses a pp̅ collisions data sample corresponding to 6.8  fb-1 at √s=1.96  TeV collected by the CDF II detector at the Tevatron collider. The total and differential branching ratios for Λb0→Λμ+μ- are measured. We find B(Λb0→Λμ+μ-)=[1.73±0.42(stat)±(syst)]×10-6. We also report the first measurement of the differential branching ratio of Bs0→ϕμ+μ-, using 49 signal events. In addition, we report branching ratios for B+→K+μ+μ-, B0→K0μ+μ-, and B→K*(892)μ+μ- decays.}, organization = {We thank the Fermilab staff and the technical staffs of the participating institutions for their vital contributions. This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Culture, Sports, Science and Technology of Japan; the Natural Sciences and Engineering Research Council of Canada; the National Science Council of the Republic of China; the Swiss National Science Foundation; the A.P. Sloan Foundation; the Bundesministerium für Bildung und Forschung, Germany; the World Class University Program, the National Research Foundation of Korea; the Science and Technology Facilities Council and the Royal Society, UK; the Institut National de Physique Nucleaire et Physique des Particules/CNRS; the Russian Foundation for Basic Research; the Ministerio de Ciencia e Innovación, and Programa ConsoliderIngenio 2010, Spain; the Slovak R&D Agency; and the Academy of Finland.}, publisher = {American Physical Society}, publisher = {Physical Review Letters, 2011, 107(20), 201802}, title = {Observation of the baryonic flavor-changing neutral current decay Λb0→Λμ+μ-}, author = {Aaltonen, Timo Antero and Álvarez González, Bárbara and Casal Laraña, Bruno and Cuevas Maestro, Francisco Javier and Gómez Gramuglio, Gervasio and Palencia Cortezón, José Enrique and Rodrigo Anoro, Teresa and Ruiz Jimeno, Alberto and Scodellaro, Luca and Vila Álvarez, Iván and Vilar Cortabitarte, Rocío}, }