A search is performed for a Higgs boson produced in association with a Z boson and decaying into two photons, using the L3 data collected at LEP at a centre-of-mass energy of 189 GeV. All decay modes ...of the Z are considered. No signal is observed and limits on the branching fraction of the Higgs boson decay into two photons as a function of the Higgs mass are derived assuming a Standard Model production rate. A lower limit on the mass of a fermiophobic Higgs is set at 94.9 GeV at 95% confidence level.
We investigate Bose-Einstein correlations (BEC) in W-pair production at $\sqrt{s}\simeq 189 \GeV$ using the L3 detector at LEP. We observe BEC between particles from a single W decay in good ...agreement with those from a light-quark Z~decay sample. We investigate their possible existence between particles coming from different W's. No evidence for such \interW\ BEC is found.
The structure functions of real and virtual photons are derivedfrom cross section measurements of the reaction$\rm e^+e^-\rightarrow e^+e^- + \hbox{hadrons}$ at LEP.The reaction is studied at ...$\sqrt{\rm {s}} \simeq 91$ GeV with the L3detector. One of the final state electrons is detected at a large angle relative to the beam direction, leading to $Q^2$ values between40 GeV$^2$ and 500 GeV$^2$.The other final state electron is either undetected or it is detected ata four-momentum transfer squared $P^2$ between 1 GeV$^2$ and 8 GeV$^2$.These measurements are compared with predictions of the Quark PartonModel and other QCD based models.
Data from the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) satellite experiment were used to measure the geomagnetic cutoff for high-energy (>80 MeV) protons ...during the 14 December 2006 geomagnetic storm. The variations of the cutoff latitude as a function of rigidity were studied on relatively short timescales, corresponding to spacecraft orbital periods (94 min). Estimated cutoff values were compared with those obtained by means of a trajectory tracing approach based on a dynamical empirical modeling of the Earth's magnetosphere. We found significant variations in the cutoff latitude, with a maximum suppression of about 7 deg at lowest rigidities during the main phase of the storm. The observed reduction in the geomagnetic shielding and its temporal evolution were related to the changes in the magnetospheric configuration, investigating the role of interplanetary magnetic field, solar wind and geomagnetic parameters. PAMELA's results represent the first direct measurement of geomagnetic cutoffs for protons with kinetic energies in the sub-GeV and GeV region.
Single W boson production in electron-positron collisions is studied with the L3 detector at LEP. The data sample collected at a centre-of-mass energy of $\sqrt{s} = 188.7 \mathrm{\ Ge\kern -0.1em ...V}{}$ corresponds to an integrated luminosity of $176.4\,\mbox{pb$^{-1}$}$. Events with a single energetic lepton or two acoplanar hadronic jets are selected. Within phase-space cuts, the total cross-section is measured to be $0.53 \pm 0.12 \pm 0.03 \ \rm{pb}$, consistent with the Standard Model expectation. Including our single W boson results obtained at lower $\sqrt{s}$, the WW$\gamma$ gauge couplings $\kappa_\gamma$ and $\lambda_\gamma$ are determined to be \mbox{$\kappa_\gamma = 0.93 \pm 0.16 \pm 0.09$} and \mbox{$\lambda_\gamma = -0.31^{+0.68}_{-0.19} \pm 0.13$}.
We present upper limits in the hard X-ray and gamma-ray bands at the time of the LIGO gravitational-wave event GW 151226 derived from the CALorimetric Electron Telescope (CALET) observation. The main ...instrument of CALET, CALorimeter (CAL), observes gamma-rays from ~1 GeV up to 10 TeV with a field of view of ~2 sr. The CALET gamma-ray burst monitor (CGBM) views ~3 sr and ~2pi sr of the sky in the 7 keV - 1 MeV and the 40 keV - 20 MeV bands, respectively, by using two different scintillator-based instruments. The CGBM covered 32.5% and 49.1% of the GW 151226 sky localization probability in the 7 keV - 1 MeV and 40 keV - 20 MeV bands respectively. We place a 90% upper limit of 2 x 10^{-7} erg cm-2 s-1 in the 1 - 100 GeV band where CAL reaches 15% of the integrated LIGO probability (~1.1 sr). The CGBM 7 sigma upper limits are 1.0 x 10^{-6} erg cm-2 s-1 (7-500 keV) and 1.8 x 10^{-6} erg cm-2 s-1 (50-1000 keV) for one second exposure. Those upper limits correspond to the luminosity of 3-5 x 10^{49} erg s-1 which is significantly lower than typical short GRBs.
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Food Involvement reflects the bond between consumer and food, and serves as a means of expression, identity and social recognition. Yet no existing scales are able to assess the complex ...psychological nature of Food Involvement. To fill this gap, this study developed and validated a Psychological Food Involvement Scale (PFIS). Data were collected by an online self-report questionnaire, involving 476 Italians aged 20-72 years (M = 48.13, SD = 13.18). The structure and psychometric properties of PFIS were examined through an exploratory and a confirmatory factor analysis, and construct validity was assessed by correlating it with Food Involvement Scale, Food Variety Seeking Scale and the General Health Interest Scale. As a behavioural indicator of validity, food and drink consumption was assessed using the Dietary Habits and Nutrition Beliefs Questionnaire. Factor analysis indicated that the PFIS comprised 19 items grouped in four stable dimensions: Emotional Balance; Self-Realization; Social Affirmation; Social Bonding. People more psychologically involved in food were more interested in healthy eating and more likely to vary their diet. The PFIS discriminated between dietary patterns. Higher PFIS scores were associated with frequent consumption of meat/fish and wholegrains/legumes. Frequent intake of meat/fish and snacks was associated with Social Bonding and meat/fish with Emotional Balance. The PFIS also explained consumption of vegetable drinks and lactose-free milk indicating the symbolic value ascribed to them related to self-expression, acceptance by others, and emotions. This implies potential for the PFIS for use in research to understand food choice and promote healthy eating.
This work was supported by the Fondazione Cariplo and Regione Lombardia within the CRAFT (Cremona Agri-Food Technologies) project ID 2018/2757.
The measurements of Rb = sigma(e+e- -> bb~)/sigma(e+e- -> qq~) and of the b quark forward-backward charge asymmetry, A^b_fb, at centre-of-mass energies above the Z pole are described. The measurement ...of Rb is performed at \root{s} between 130 and 189 GeV using a b-tagging method that exploits the relatively large decay length of b-hadrons. The measurement of A^b_fb is performed using the large statistics event sample collected at \root{s}=189 GeV with a lepton-tag analysis based on the selection of prompt muons and electrons. The results at \root{s}=189 GeV are: Rb = 0.163 +/- 0.013 (stat.) +/- 0.005 (syst.), A^b_fb = 0.61 +/- 0.18 (stat.) +/- 0.09 (syst.).
A search for a Higgs boson decaying into invisible particles is performed using the datacollected at LEP by the L3 experiment at centre-of-mass energies of$183\gev{}$ and $189\gev{}$. The integrated ...luminosities are respectively 55.3~\pb{} and 176.4~\pb{}.The observed candidates are consistent with the expectations from StandardModel processes.In the hypothesis that the production cross section of this Higgs bosonequals the Standard Model one and the branching ratio into invisibleparticles is $100\%$, a lower masslimit of $89.2\gev{}$ is set at $95\%$ confidence level.
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