IFAE

About: IFAE is a other organization based out in Barcelona, Spain. It is known for research contribution in the topics: Large Hadron Collider & Galaxy. The organization has 664 authors who have published 1270 publications receiving 51097 citations. The organization is also known as: Instituto de Fisica de Altas Energias & IFAE.

Search for Higgs and Z boson decays to ϕγ with the ATLAS detector

Abstract: A search for the decays of the Higgs and Z bosons to a ϕ meson and a photon is performed with a pp collision data sample corresponding to an integrated luminosity of 2.7 fb^{-1} collected at sqrt[s]=13 TeV with the ATLAS detector at the LHC. No significant excess of events is observed above the background, and 95% confidence level upper limits on the branching fractions of the Higgs and Z boson decays to ϕγ of 1.4×10^{-3} and 8.3×10^{-6}, respectively, are obtained.

Linear viscoelastic dynamics in holography

Abstract: We study the mechanical response under time dependent sources of a simple class of holographic models that exhibit viscoelastic features. The ratio of viscosity over elastic modulus defines an intrinsic relaxation timescale---the so-called Maxwell relaxation time ${\ensuremath{\tau}}_{M}$, which has been identified traditionally with the relaxation timescale. We compute explicitly the relaxation time in our examples and find that it differs from ${\ensuremath{\tau}}_{M}$. At high temperatures ${\ensuremath{\tau}}_{M}$ overestimates the actual relaxation time, although not by much and moreover it still captures reasonably well the temperature behavior. At sufficiently low temperatures the situation is reversed: ${\ensuremath{\tau}}_{M}$ underestimates the actual relaxation time, in some cases quite drastically. Moreover, when ${\ensuremath{\tau}}_{M}$ underestimates the real-time response exhibits an overshoot phenomenon before relaxation. We comment on the $T=0$ limit, where the relaxation is power law because our models exhibit criticality.

Erratum to: Study of the spin and parity of the Higgs boson in diboson decays with the ATLAS detector

Abstract: Unfortunately in the HTML of the article the authors, M. Ishino, T. Kunigo, T. Sumida and T. Tashiro, are assigned to the wrong affiliation. In the PDF of the article the assignment to the affiliation is correct. The online version of the original article can be found under doi:10.1140/epjc/s10052-015-3685-1. The online version of the original article can be found at http://dx.doi.org/10.1140/epjc/s10052-015-3685-1.

J/psi->VP decays and the quark and gluon content of the eta and eta'

Abstract: The $\eta$-$\eta^\prime$ pseudoscalar mixing angle and the gluonium content of the $\eta^\prime$ meson are deduced from an updated phenomenological analysis of $J/\psi$ decays into a vector and a pseudoscalar meson. In absence of gluonium, the value of the mixing angle in the quark-flavour basis is found to be $\phi_P=(40.7\pm 2.3)^\circ$. In presence of gluonium, the values for the mixing angle and the gluonic content of the $\eta^\prime$ wave function are $\phi_P=(44.6\pm 4.4)^\circ$ and $Z^2_{\eta^\prime}=0.29^{+0.18}_{-0.26}$, respectively. The newly reported values of $B(J/\psi\to\rho\pi)$ by the BABAR and BES Collaborations are crucial to get a consistent description of data.

Search for dijet resonances in events with an isolated charged lepton using √s = 13 TeV proton-proton collision data collected by the ATLAS detector

Abstract: A search for dijet resonances in events with at least one isolated charged lepton is performed using 139 fb(-1) of root s = 13 TeV proton-proton collision data recorded by the ATLAS detector at the LHC. The dijet invariant-mass (m(jj)) distribution constructed from events with at least one isolated electron or muon is searched in the region 0.22 < m(jj) < 6.3 TeV for excesses above a smoothly falling background from Standard Model processes. Triggering based on the presence of a lepton in the event reduces limitations imposed by minimum transverse momentum thresholds for triggering on jets. This approach allows smaller dijet invariant masses to be probed than in inclusive dijet searches, targeting a variety of new-physics models, for example ones in which a new state is produced in association with a leptonically decaying W or Z boson. No statistically significant deviation from the Standard Model background hypothesis is found. Limits on contributions from generic Gaussian signals with widths ranging from that determined by the detector resolution up to 15% of the resonance mass are obtained for dijet invariant masses ranging from 0.25 TeV to 6 TeV. Limits are set also in the context of several scenarios beyond the Standard Model, such as the Sequential Standard Model, a technicolor model, a charged Higgs boson model and a simplified Dark Matter model.