First evidence for the decay Bs -> mu+ mu-

R. Aaij; S. Barsuk; O. Callot; J. He; B. Jean-Marie; J. Lefrançois; F. Machefert; A. Martin Sanchez; M. Nicol; P. Robbe; M.-H. Schune; B. Viaud; I. Videau; E. Ben-Haim; M. Benayoun; P. David; L. Del Buono; A. Martens; Z.J. Ajaltouni; O. Deschamps; E. Cogneras; I. El Rifai; P. Henrard; M. Hoballah; M. Jahjah Hussein; R. Lefèvre; L. Li Gioi; S. Monteil; V. Niess; P. Perret; D.A. Roa Romero; K. Sobczak; C. Adrover; E. Aslanides; J. Cogan; R. Legac; O. Leroy; G. Mancinelli; E. Maurice; M. Perrin-Terrin; M. Sapunov; J. Serrano; A. Tsaregorodtsev; I. De Bonis; D. Decamp; Ph. Ghez; P. Hopchev; J.-P. Lees; I.V. Machikhiliyan; M.-N. Minard; B. Pietrzyk; W. Qian; S. T'Jampens; V. Tisserand; E. Tournefier

HAL: in2p3-00751272, version 1

arXiv: 1211.2674

DOI: 10.1103/PhysRevLett.110.021801

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First evidence for the decay Bs -> mu+ mu-
Aaij R., Barsuk S., Callot O., He J., Jean-Marie B. et al
Physical Review Letters 110 (2013) 021801 - http://hal.in2p3.fr/in2p3-00751272

Subject(s):

Physics/High Energy Physics - Experiment

Title:

First evidence for the decay Bs -> mu+ mu-

Author:

R. Aaij, S. Barsuk¹, O. Callot¹, J. He¹, B. Jean-Marie¹, J. Lefrançois¹, F. Machefert¹, A. Martin Sanchez¹, M. Nicol¹, P. Robbe¹, M.-H. Schune¹, B. Viaud¹, I. Videau¹, E. Ben-Haim², M. Benayoun², P. David², L. Del Buono², A. Martens², Z.J. Ajaltouni³, O. Deschamps³, E. Cogneras³, I. El Rifai³, P. Henrard³, M. Hoballah³, M. Jahjah Hussein³, R. Lefèvre³, L. Li Gioi³, S. Monteil³, V. Niess³, P. Perret³, D.A. Roa Romero³, K. Sobczak³, C. Adrover⁴, E. Aslanides⁴, J. Cogan⁴, R. Legac⁴, O. Leroy⁴, G. Mancinelli⁴, E. Maurice⁴, M. Perrin-Terrin⁴, M. Sapunov⁴, J. Serrano⁴, A. Tsaregorodtsev⁴, I. De Bonis⁵, D. Decamp⁵, Ph. Ghez⁵, P. Hopchev⁵, J.-P. Lees⁵, I.V. Machikhiliyan⁵, M.-N. Minard⁵, B. Pietrzyk⁵, W. Qian⁵, S. T'Jampens⁵, V. Tisserand⁵, E. Tournefier⁵

Laboratory:

1:	LAL - Laboratoire de l'Accélérateur Linéaire

http://www.lal.in2p3.fr/

CNRS : UMR8607 – IN2P3 – Université Paris XI - Paris Sud

Centre Scientifique d'Orsay B.P. 34 91898 ORSAY Cedex

France

2:	LPNHE - Laboratoire de Physique Nucléaire et de Hautes Énergies

http://www-lpnhep.in2p3.fr

CNRS : UMR7585 – IN2P3 – Université Pierre et Marie Curie (UPMC) - Paris VI – Université Paris VII - Paris Diderot

Barre 12-22, 1er étage 4 Place Jussieu 75252 Paris Cedex 05

France

3:	LPC-CLERMONT - Laboratoire de Physique Corpusculaire de Clermont-Ferrand

http://clrwww.in2p3.fr/

CNRS : UMR6533 – IN2P3 – Université Blaise Pascal - Clermont-Ferrand II

Campus des Cézeaux 24, avenue des Landais BP 80026 63171 Aubière Cedex

France

4:	CPPM - Centre de Physique des Particules de Marseille

http://marwww.in2p3.fr/

CNRS : UMR7346 – IN2P3 – Université de la Méditerranée - Aix-Marseille II

163, avenue de Luminy - Case 902 - 13288 Marseille cedex 09

France

5:	LAPP - Laboratoire d'Annecy le Vieux de Physique des Particules

http://wwwlapp.in2p3.fr/

CNRS : UMR5814 – IN2P3 – Université de Savoie

9 Chemin de Bellevue - BP 110 - 74941 Annecy-le-Vieux CEDEX - France

France

Abstract:

A search for the rare decays Bs->mu+mu- and B0->mu+mu- is performed using data collected in 2011 and 2012 with the LHCb experiment at the Large Hadron Collider. The data samples comprise 1.1 fb^-1 of proton-proton collisions at sqrt{s} = 8 TeV and 1.0 fb^-1 at sqrt{s}=7 TeV. We observe an excess of Bs -> mu+ mu- candidates with respect to the background expectation. The probability that the background could produce such an excess or larger is 5.3 x 10^-4 corresponding to a signal significance of 3.5 standard deviations. A maximum-likelihood fit gives a branching fraction of BR(Bs -> mu+ mu-) = (3.2^{+1.5}_{-1.2}) x 10^-9, where the statistical uncertainty is 95% of the total uncertainty. This result is in agreement with the Standard Model expectation. The observed number of B0 -> mu+ mu- candidates is consistent with the background expectation, giving an upper limit of BR(B0 -> mu+ mu-) < 9.4 x 10^-10 at 95% confidence level.

Collaboration/Project:

LHCb

Document of the type:

Article in peer-reviewed journal

Publication or writing
date:

2013

Journal:

Physical Review Letters (Phys. Rev. Lett.)
Publisher	American Physical Society
ISSN	0031-9007 (eISSN : 1079-7114)

Volume:

110

Page/Article:

021801

Internal call number:

CERN-PH-EP-2012-335; LHCb-PAPER-2012-043

Comments:

3+6 pages, 2 figures, submitted to Phys. Rev. Lett. - See paper for full list of authors

Fulltext link:

http://fr.arXiv.org/abs/1211.2674


in2p3-00751272, version 1
http://hal.in2p3.fr/in2p3-00751272
oai:hal.in2p3.fr:in2p3-00751272
From: Françoise Marechal <>
Submitted on: Tuesday, 13 November 2012 10:19:42
Updated on: Monday, 14 January 2013 11:30:09