The 38th International Conference on High Energy Physics (ICHEP 2016) is taking place in Chicago, USA, where the CMS Collaboration will present more than 70 new results approved since the last major conference (LHCP, June 2016). Many of these results use the new data collected by CMS in 2016, corresponding to an integrated luminosity of 13 fb−1. With five times more statistics than what was previously collected at a centre-of-mass energy of 13 TeV, CMS is significantly increasing its physics reach with respect to Run 1, especially in studies of the Higgs sector and in searches for new physics. Analyses and results from Run 2 are taking reign at CMS.
One of the highlights from CMS for ICHEP is the full re-discovery programme around the Higgs boson with a mass of 125 GeV, providing independent observations in the H→γγ and H→ZZ*→4l channels well above 5 standard deviations. Clear signals are observed in the mass spectrum, as shown in Figure 1. The analyses are completed with dedicated measurements of the cross-section in the fiducial volume, mass and spin-parity studies, and searches for additional Higgs bosons at higher masses. All results were found to be consistent with Standard Model expectations and with previous CMS results from Run 1.
Another Higgs channel of special interest is the production of a Higgs in association with top-quark pairs (ttH), given the mild excess of ~2σ (relative to the SM prediction) observed by CMS in Run 1. The ttH production channel is the only possibility to study the top-Higgs coupling, since the Higgs mass is too low for a Higgs to decay into a top quark pair. The analysis from Run 2 uses multilepton final states to target Higgs decays into WW, ZZ, and ττ. The resulting measurement of the signal strength of μ=2.0 +0.8/−0.7 is consistent with the Standard Model expectation of μ=1 at the 1.4σ level. Higgs studies at 13 TeV presented at ICHEP are completed with searches for new scalars at high mass decaying into b-quark pairs, charged Higgs production, associated single-top production and search for di-Higgs boson production in bbττ and bbWW final states.
The analysis of the initial data collected at 13 TeV in 2015 and data from Run 1 showed evidence for an excess in the high-mass di-photon search near 750 GeV (arXiv:1606.04093). More data were necessary to confirm or reject an excess. Therefore the analysis of the di-photon spectrum near 750 GeV with the new 2016 data became one of the priorities in CMS. The new results show no significant excess in the relevant region (Figure 2) and do not confirm the previously observed evidence of an excess. Using only 2016 data, an upper limit on the cross-section of 1.5 fb at 95% CL is obtained. Additional searches in related channels like X→Zγ have not shown any significant excess around 750 GeV mass either.
SUSY searches are also taking full advantage of the increased statistics. While no significant excesses were observed in the new data, mass limits increased by a few hundreds of GeV on almost all fronts. That is the case of gluino and top-squark (or stop) searches in high-multiplicity states associated to missing transverse energy. Updated analyses in photonic or leptonic final states (lepton pairs of same or opposite sign, multileptonic final states) also led to improved limits. Finally, a new generation of SUSY analyses is targeting complicated scenarios like compressed spectra or particles exclusively produced via electroweak interactions. On this front, improvements as large as 300 GeV in mass reach were obtained, depending on model assumptions.
In the Exotica sector the analysis of the new data excluded the presence of new massive Z bosons up to 4 TeV and of new string resonances decaying into pairs of jets up to 7.4 TeV. CMS keeps an intensive, comprehensive dark-matter search programme in the so-called “mono-X” final states, where high-mass mediators decay into invisible particles (dark matter) and recoil against high-pT X visible objects. The most sensitive “mono-jet” analysis is now excluding mediator masses up to 2 TeV in several standard scenarios for low masses of the dark-matter candidate.
CMS continues to perform precise measurements of Standard Model processes, with a special focus on high-mass final states, where Run 2 is particularly advantageous. Some examples are the search for anomalous triple-gauge couplings in Zγ final states, the measurement of the ttW and ttZ cross-sections, or a sensitive limit of 10 times the Standard Model expectations on anomalous production of four top quarks in the final state. CMS is also presenting new heavy-ion results from the most recent pp, pPb and PbPb runs taken at 5 TeV centre-of-mass per nucleon. Last but not least, data from Run 1 keep providing extremely interesting physics results, like a first high-statistics study of Z+charm production at the LHC. An investigation of the B0sπ spectrum did not show any evidence for resonant structures around 5568 MeV, leading to a conservative limit of about half the rate claimed by the D0 experiment at the 95% CL.
The extraordinary performance of the LHC has allowed this successful first exploration of a new energy domain. It also makes us confident about the future of the rich programme of research of CMS, both pursuing discovery of new phenomena and improving our knowledge of nature.
More information at http://cern.ch/cms-results/public-results/preliminary-results/ICHEP-2016...
List of Recent Results from CMS for the ICHEP 2016 Conference
BTV-15-002: Identification of double-b quark jets in Boosted Topologies.
BTV-16-001: Identification of c-quark jets at the CMS experiment.
JME-16-004: Performance of Missing Energy Reconstruction in 13 TeV pp data.
BPH-15-002: Measurement of the Lambda_b polarization and the angular parameters of the decay Lambda_b to J/psi Lambda.
BPH-16-002: Investigation of Bs Pi spectrum.
B2G-16-006: Search for singly-produced Vector-like Quarks decaying to Wb, semi-leptonic channel.
B2G-16-008: Search for HH resonances in the 4b final state.
B2G-16-009: Search for Wprime->tb in the all-hadronic final state at sqrt(s)=13 TeV.
B2G-16-010: Search for ZV Resonances in Semi-leptonic Final States at 13 TeV.
B2G-16-017: Search for Wprime->tb semi-leptonic.
B2G-16-020: Search for VW diboson resonances in semi-leptonic final state.
EXO-16-005: Search for dark matter in association with a top quark pair.
EXO-16-009: Search for excited leptons in llgamma final state.
EXO-16-010: Search for dark matter, extra dimensions, and unparticles in Z(ll) MET final state.
EXO-16-011: Search for dark matter in H(gammagamma)+MET channel.
EXO-16-012: Search for dark matter in H(bb)+MET channel.
EXO-16-015: Search for excited quarks in photon+jet final state.
EXO-16-022: Search for displaced leptons in the e-mu channel.
EXO-16-023: Search for right-handed W and third-generation leptoquarks in tau_had tau_l 2jets final state.
EXO-16-025: Search for high-mass resonances in Z(qq)gamma final state at 8 TeV.
EXO-16-026: Search for heavy composite Majorana neutrinos in 2l 2jets final state.
EXO-16-027: Search for high-mass resonances in diphoton final state using 2016 data.
EXO-16-030: Search for low-mass resonances decaying to boosted jets.
EXO-16-031: Search for high-mass resonances in dilepton final state with 2016 data.
EXO-16-032: Search for high-mass resonances in dijet final state with 2016 data.
EXO-16-034: Search for high-mass resonances in Z(ll)gamma final states with 2016 data.
EXO-16-035: Search for high-mass resonances in Z(qq)gamma final state with 2016 data.
EXO-16-036: Search for heavy stable charged particles with 2016 data.
EXO-16-037: Search for dark matter in jets+MET final state with 2016 data.
EXO-16-038: Search for dark matter in Z(ll) MET final state using the 2016 dataset.
EXO-16-039: Search for dark matter in photon+MET final state with 2016 data.
EXO-16-040: Search for dark matter in top+MET final state with 2016 data.
EXO-16-043: Search for pair production of first generation leptoquarks.
HIG-16-015: Searches for light pseudoscalar boson in the decay of h(125) with 8 TeV data.
HIG-16-016: Combination of searches for invisible Higgs boson decays using Run1+Run2 data samples.
HIG-16-019: Search for Higgs production in association with a single top quark and decaying to bb.
HIG-16-020: Higgs to gammagamma measurements at 13 TeV using 2016 data.
HIG-16-022: Search for the ttH process with multilepton decays using the 2016 data.
HIG-16-023: Search for high mass Higgs to WW with fully leptonic decays using 2015 data.
HIG-16-024: Search for the nonresonant HH process with WWbb decays using 2015 data.
HIG-16-025: Search for a heavy Higgs boson decaying to bottom quark pairs in the 13 TeV data sample.
HIG-16-027: Search for charged Higgs bosons in WZ decays at 13 TeV.
HIG-16-028: Search for H(bb)H(tautau) decays from non-resonant production.
HIG-16-029: Search for H(bb)H(tautau) decays from resonant production.
HIG-16-030: Search for charged Higgs production and decay into cb quark pairs with 8 TeV data.
HIG-16-033: Measurements of properties of the Higgs boson and search for an additional resonance in the four-lepton final state at sqrt(s) = 13 TeV.
HIN-16-003: Dijet pseudorapidity distributions in pp and pPb collisions at 5 TeV with the CMS detector.
HIN-16-005: Transverse momentum balance of b-jet pairs in PbPb collisions at 5 TeV.
HIN-16-006: Splitting function in pp and PbPb collisions at 5 TeV.
HIN-16-009: Chiral Magnetic effect in pPb and PbPb collisions.
BPH-15-002: Measurement of Lambda_b polarization and angular dist. in Lambda_b to J/psi Lambda0.
BPH-16-002: Investigation of Bs Pi spectrum.
SMP-15-009: Z+c cross section at 8 TeV.
SMP-16-004: Z(nunu)gamma cross section at 13 TeV.
SMP-16-005: W+jets at 13 TeV.
SMP-16-009: Drell-Yan mass differential cross section measurement at 13 TeV.
SUS-16-012: Search for SUSY in Events with a Higgs Decaying to Two Photons Using the Razor Variables.
SUS-16-013: Search for RPV SUSY in 0l and 1l final states.
SUS-16-014: Search for supersymmetry in the multijet and missing transverse momentum channel in pp collisions at 13 TeV.
SUS-15-015: Search for new physics in the all-hadronic final state with the MT2 variable.
SUS-16-016: Search for new physics in final states with jets and missing transverse momentum in sqrt(s) = 13 TeV pp collisions with the alpha_T variable.
SUS-16-019: Search for supersymmetry in events with one lepton.
SUS-16-020: Search for SUSY in same-sign dilepton events at 13 TeV.
SUS-16-021: Search for SUSY in final states with opposite-sign dileptons at 13 TeV.
SUS-16-022: Search for SUSY with multileptons in 13 TeV data.
SUS-16-023: Search for SUSY in photon + MET final states at 13 TeV.
SUS-16-024: Search for electroweak SUSY production in multi-lepton final state at 13 TeV.
SUS-16-025: Search for SUSY in the soft opposite-sign dilepton final state at 13 TeV.
SUS-16-026: Search for electroweak SUSY in the WH final state at 13 TeV.
SUS-16-028: Search for direct stop pair production in the single lepton final state at 13 TeV.
SUS-16-029: Search for direct stop pair production in the fully hadronic final state at 13 TeV.
SUS-16-030: Search for SUSY with a customized top tagger at 13 TeV.
TOP-14-013: 2D-differential tt cross sections at 8 TeV.
TOP-15-008: Top mass in dileptons with MT2 and MAOS methods at 8 TeV.
TOP-16-006: Inclusive ttbar cross section in the l+jets channel at 13 TeV.
TOP-16-007: Top quark pair differential cross sections at particle level in the dilepton channel at 13 TeV.
TOP-16-010: Measurement of ttbb production at 13 TeV.
TOP-16-016: Search for standard model four-top-quark production at 13 TeV.
TOP-16-017: Measurement of the top pair-production in association with a W or Z boson (13 TeV).