Search for a standard model-like Higgs boson in the μ+ μ- and e+ e- decay channels at the LHC

A search is presented for a standard model-like Higgs boson decaying to the μ+μ− or e+e− final
states based on proton–proton collisions recorded by the CMS experiment at the CERN LHC. The data
correspond to integrated luminosities of 5.0 fb−1 at a centre-of-mass energy of 7 TeV and 19.7 fb−1 at
8 TeV for the μ+μ− search, and of 19.7 fb−1 at 8 TeV for the e+e− search. Upper limits on the production
cross section times branching fraction at the 95% confidence level are reported for Higgs boson masses
in the range from 120 to 150 GeV. For a Higgs boson with a mass of 125 GeV decaying to μ+μ−, the
observed (expected) upper limit on the production rate is found to be 7.4 (6.5+2.8
−1.9) times the standard
model value. This corresponds to an upper limit on the branching fraction of 0.0016. Similarly, for e+e−,
an upper limit of 0.0019 is placed on the branching fraction, which is ≈3.7 × 105 times the standard
model value. These results, together with recent evidence of the 125 GeV boson coupling to τ -leptons
with a larger branching fraction consistent with the standard model, confirm that the leptonic couplings
of the new boson are not flavour-universalWe congratulate our colleagues in the CERN accelerator departments
for the excellent performance of the LHC and thank the
technical and administrative staffs at CERN and at other CMS institutes
for their contributions to the success of the CMS effort.
In addition, we gratefully acknowledge the computing centres and
personnel of the Worldwide LHC Computing Grid for delivering so
effectively the computing infrastructure essential to our analyses.
Finally, we acknowledge the enduring support for the construction
and operation of the LHC and the CMS detector provided by
the following funding agencies: BMWFW and FWF (Austria); FNRS
and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil);
MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS
(Colombia); MSES and CSF (Croatia); RPF (Cyprus); MoER, ERC IUT
and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland);
CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany);
GSRT (Greece); OTKA and NIH (Hungary); DAE and DST (India);
IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Republic
of Korea); LAS (Lithuania); MOE and UM (Malaysia); CINVESTAV,
CONACYT, SEP, and UASLP-FAI (Mexico); MBIE (New Zealand); PAEC
(Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna);
MON, RosAtom, RAS and RFBR (Russia); MESTD (Serbia); SEIDI and
CPAN (Spain); Swiss Funding Agencies (Switzerland); MST (Taipei);
ThEPCenter, IPST, STAR and NSTDA (Thailand); TUBITAK and TAEK
(Turkey); NASU and SFFR (Ukraine); STFC (United Kingdom); DOE
and NSF (USA).
Individuals have received support from the Marie-Curie programme
and the European Research Council and EPLANET (European
Union); the Leventis Foundation; the A.P. Sloan Foundation;
the Alexander von Humboldt Foundation; the Belgian Federal
Science Policy Office; the Fonds pour la Formation à la
Recherche dans l’Industrie et dans l’Agriculture (FRIA-Belgium); the
Agentschap voor Innovatie door Wetenschap en Technologie (IWTBelgium);
the Ministry of Education, Youth and Sports (MEYS) of
the Czech Republic; the Council of Science and Industrial Research,
India; the HOMING PLUS programme of Foundation for Polish
Science, cofinanced from European Union, Regional Development
Fund; the Compagnia di San Paolo (Torino); the Consorzio per la
Fisica (Trieste); MIUR project 20108T4XTM (Italy); the Thalis and
Aristeia programmes cofinanced by EU-ESF and the Greek NSRF;
and the National Priorities Research Program by Qatar National Research
Fund; and the Russian Scientific Fund, grant N 14-12-0011