Limits on the Higgs boson lifetime and width from its decay to four charged leptons

<p>Constraints on the lifetime and width of the Higgs boson are obtained from H → ZZ → 4l events using data recorded by the CMS experiment during the LHC run 1 with an integrated luminosity of 5.1 and 19.7 fb−1 at a center-of-mass energy of 7 and 8 TeV, respectively. The measurement of the Higgs boson lifetime is derived from its flight distance in the CMS detector with an upper bound of τH < 1.9 × 10−13 s at the 95% confidence level (C.L.), corresponding to a lower bound on the width of ΓH > 3.5 × 10−9 MeV. The measurement of the width is obtained from an off-shell production technique, generalized to include anomalous couplings of the Higgs boson to two electroweak bosons. From this measurement, a joint constraint is set on the Higgs boson width and a parameter fΛQ that expresses an anomalous coupling contribution as an on-shell cross-section fraction. The limit on the Higgs boson width is ΓH < 46 MeV with fΛQ unconstrained and ΓH < 26 MeV for fΛQ ¼ 0 at the 95% C.L. The constraint fΛQ < 3.8 × 10−3 at the 95% C.L. is obtained for the expected standard model Higgs boson width.</p

Study of the Mass and Spin-Parity of the Higgs Boson Candidate via Its Decays to Z Boson Pairs

<p>A study is presented of the mass and spin-parity of the new boson recently observed at the LHC at a mass near 125 GeV. An integrated luminosity of 17.3  fb−1, collected by the CMS experiment in proton-proton collisions at center-of-mass energies of 7 and 8 TeV, is used. The measured mass in the ZZ channel, where both Z bosons decay to e or μ pairs, is 126.2±0.6(stat)±0.2(syst)  GeV. The angular distributions of the lepton pairs in this channel are sensitive to the spin-parity of the boson. Under the assumption of spin 0, the present data are consistent with the pure scalar hypothesis, while disfavoring the pure pseudoscalar hypothesis.</p

Determination of the top-quark pole mass and strong coupling constant from the tt production cross section in pp collisions at √s = 7 TeV

<p>The inclusive cross section for top-quark pair production measured by the CMS experiment in proton–proton collisions at a center-of-mass energy of 7 TeV is compared to the QCD prediction at next-to-next-to-leading order with various parton distribution functions to determine the top-quark pole mass, <a></a>, or the strong coupling constant,α_S. With the parton distribution function set NNPDF2.3, a pole mass of <a></a> is obtained when constraining α_S at the scale of the Z boson mass, m_Z, to the current world average. Alternatively, by constraining <a></a> to the latest average from direct mass measurements, a value of <a></a> is extracted. This is the first determination of α_S using events from top-quark production.</p

Measurement of the elliptic anisotropy of charged particles produced in PbPb collisions at√sNN=2.76 TeV

<p>The anisotropy of the azimuthal distributions of charged particles produced in √sNN = 2.76 TeV PbPb collisions is studied with the CMS experiment at the LHC. The elliptic anisotropy parameter, v2, defined as the second coefficient in a Fourier expansion of the particle invariant yields, is extracted using the event-plane method, two- and four-particle cumulants, and Lee-Yang zeros. The anisotropy is presented as a function of transverse momentum (pT), pseudorapidity (η) over a broad kinematic range, 0.3 < pT < 20 GeV/c, |η| < 2.4, and in 12 classes of collision centrality from 0 to 80%. The results are compared to those obtained at lower center-of-mass energies, and various scaling behaviors are examined. When scaled by the geometric eccentricity of the collision zone, the elliptic anisotropy is found to obey a universal scaling with the transverse particle density for different collision systems and center-of-mass energies.</p

Search for supersymmetry with photons in pp collisions at s√=8 TeV

<p>Two searches for physics beyond the standard model in events containing photons are presented. The data sample used corresponds to an integrated luminosity of 19.7  fb−1 of proton-proton collisions at s√=8  TeV, collected with the CMS experiment at the CERN LHC. The analyses pursue different inclusive search strategies. One analysis requires at least one photon, at least two jets, and a large amount of transverse momentum imbalance, while the other selects events with at least two photons and at least one jet, and uses the razor variables to search for signal events. The background expected from standard model processes is evaluated mainly from data. The results are interpreted in the context of general gauge-mediated supersymmetry, with the next-to-lightest supersymmetric particle either a bino- or wino-like neutralino, and within simplified model scenarios. Upper limits at the 95% confidence level are obtained for cross sections as functions of the masses of the intermediate supersymmetric particles.</p

Search for pair produced fourth-generation up-type quarks in pp collisions at √s = 7 TeV with a lepton in the final state

<p>The results of a search for the pair production of a fourth-generation up-type quark (t ) in proton–proton collisions at √s = 7 TeV are presented, using data corresponding to an integrated luminosity of about 5.0 fb−1 collected by the Compact Muon Solenoid experiment at the LHC. The t quark is assumed to decay exclusively to a W boson and a b quark. Events with a single isolated electron or muon, missing transverse momentum, and at least four hadronic jets, of which at least one must be identified as a b jet, are selected. No significant excess of events over standard model expectations is observed. Upper limits for the t t¯ production cross section at 95% confidence level are set as a function of t mass, and t -quark production for masses below 570 GeV is excluded. The search is equally sensitive to nonchiral heavy quarks decaying to Wb. In this case, the results can be interpreted as upper limits on the production cross section times the branching fraction to Wb.</p

RUBCN/rubicon and EGFR regulate lysosomal degradative processes in the retinal pigment epithelium (RPE) of the eye

<p>Macroautophagy/autophagy is an intracellular stress survival and recycling system whereas phagocytosis internalizes material from the extracellular milieu; yet, both pathways utilize lysosomes for cargo degradation. Whereas autophagy occurs in all cells, phagocytosis is performed by cell types such as macrophages and the retinal pigment epithelial (RPE) cells of the eye where it is supported by the noncanonical autophagy process termed LC3-associated phagocytosis (LAP). Autophagy and LAP are distinct pathways that use many of the same mediators and must compete for cellular resources, suggesting that cells may regulate both processes under homeostatic and stress conditions. Our data reveal that RPE cells promote LAP through the expression of RUBCN/Rubicon (RUN domain and cysteine-rich domain containing Beclin 1-interacting protein) and suppress autophagy through the activation of EGFR (epidermal growth factor receptor). In the morning when photoreceptor outer segments (POS) phagocytosis and LAP are highest, RUBCN expression is increased. At the same time, outer segment phagocytosis activates the EGFR resulting in MTOR (mechanistic target of rapamycin [serine/threonine kinase]) stimulation, the accumulation of SQSTM1/p62, and the phosphorylation of BECN1 (Beclin 1, autophagy related) on an inhibitory residue thereby suppressing autophagy. Silencing <i>Rubcn</i>, preventing EGFR activity or directly inducing autophagy in RPE cells by starvation inhibits phagocytic degradation of POS. Thus, RPE cells regulate lysosomal pathways during the critical period of POS phagocytosis to support retinal homeostasis.</p

Measurements of the branching fractions and helicity amplitudes in B⃗D*ρ decays

Using 9.1fb-1 of e+e- data collected at the Υ(4S) with the CLEO detector using the Cornell Electron Storage Ring, measurements are reported for both the branching fractions and the helicity amplitudes for the decays B-→D*0ρ- and B0→D*+ρ-. The fraction of longitudinal polarization in B0→D*+ρ- is found to be consistent with that in B0→D*+l-ν̅ at q2=Mρ2, indicating that the factorization approximation works well. The longitudinal polarization in the B- mode is similar. The measurements also show evidence of nontrivial final-state interaction phases for the helicity amplitudes.</p

Measurement of the η′-Meson Mass using J/ψ→γη′

We measure the mass of the η′ meson using ψ(2S)→π+π-J/ψ, J/ψ→γη′ events acquired with the CLEO-c detector operating at the CESR e+e- collider. Using three decay modes, η′→ρ0γ, η′→π+π-η with η→γγ, and η′→π+π-η with η→π+π-π0, we find Mη′=957.793±0.054±0.036   MeV, in which the uncertainties are statistical and systematic, respectively. This result is consistent with but substantially more precise than the current world average.</p

Observation of J/ψ→3γ

We report the first observation of the decay J/ψ→3γ. The signal has a statistical significance of 6σ and corresponds to a branching fraction of B(J/ψ→3γ)=(1.2±0.3±0.2)×10-5, in which the errors are statistical and systematic, respectively. The measurement uses ψ(2S)→π+π-J/ψ events acquired with the CLEO-c detector operating at the CESR e+e- collider.</p