Hydrothermal pressure-temperature control on CO2 emissions and seismicity at Campi Flegrei (Italy)

Fluids supplied by stored magma at depth are causal factors of volcanic unrest, as they can cause pressurization/heating of hydrothermal systems. However, evidence for links between hydrothermal pressurization, CO2 emission and volcano seismicity have remained elusive. Here, we use recent (2010−2020) observations at Campi Flegrei caldera (CFc) to show hydrothermal pressure, gas emission and seismicity at CFc share common source areas and well-matching temporal evolutions. We interpret the recent escalation in seismicity and surface gas emissions as caused by pressure-temperature increase at the top of a vertically elongated (0.3–2 km deep) gas front. Using mass (steam) balance considerations, we show hydrothermal pressurization is causing energy transfer from the fluids to the host rocks, ultimately triggering low magnitude earthquakes within a seismogenetic volume containing the hydrothermal system. This mechanism is probably common to other worldwide calderas in similar hydrothermal activity state

Measurement of the neutron detection efficiency of a 80% absorber - 20% scintillating fibers calorimeter

The neutron detection efficiency of a sampling calorimeter made of 1 mm diameter scintillating fibers embedded in a lead/bismuth structure has been measured at the neutron beam of the The Svedberg Laboratory at Uppsala. A significant enhancement of the detection efficiency with respect to a bulk organic scintillator detector with the same thickness is observed.Comment: 10 pages, 7 figure

Heavy-light decay topologies as a new strategy to discover a heavy gluon

We study the collider phenomenology of the lightest Kaluza-Klein excitation of the gluon, G*, in theories with a warped extra dimension. We do so by means of a two-site effective lagrangian which includes only the lowest-lying spin-1 and spin-1/2 resonances. We point out the importance of the decays of G* to one SM plus one heavy fermion, that were overlooked in the previous literature. It turns out that, when kinematically allowed, such heavy-light decays are powerful channels for discovering the G*. In particular, we present a parton-level Montecarlo analysis of the final state Wtb that follows from the decay of G* to one SM top or bottom quark plus its heavy partner. We find that at \sqrt{s} = 7 TeV and with 10 fb^{-1} of integrated luminosity, the LHC can discover a KK gluon with mass in the range M_{G*} = (1.8 - 2.2) TeV if its coupling to a pair of light quarks is g_{G*qqbar} = (0.2-0.5) g_3. The same process is also competitive for the discovery of the top and bottom partners as well. We find, for example, that the LHC at \sqrt{s} = 7 TeV can discover a 1 TeV KK bottom quark with an integrated luminosity of (5.3 - 0.61) fb^{-1} for g_{G*qqbar} = (0.2-0.5) g_3.Comment: 36 pages, 13 figures. v2: a few typos corrected, comments added, version published in JHE

Measurement of {\eta} meson production in {\gamma}{\gamma} interactions and {\Gamma}({\eta}-->{\gamma}{\gamma}) with the KLOE detector

We present a measurement of {\eta} meson production in photon-photon interactions produced by electron-positron beams colliding with \sqrt{s}=1 GeV. The measurement is done with the KLOE detector at the \phi-factory DA{\Phi}NE with an integrated luminosity of 0.24 fb^{-1}. The e^+e^- --> e^+e^-{\eta} cross section is measured without detecting the outgoing electron and positron, selecting the decays {\eta}-->{\pi}^+{\pi}^-{\pi}^0 and {\eta}-->{\pi}^0{\pi}^0{\pi}^0. The most relevant background is due to e^+e^- --> {\eta}{\gamma} when the monochromatic photon escapes detection. The cross section for this process is measured as {\sigma}(e^+e^- -->{\eta}{\gamma}) = (856 \pm 8_{stat} \pm 16_{syst}) pb. The combined result for the e^+e^- -->e^+e^-{\eta} cross section is {\sigma}(e^+e^- -->e^+e^-{\eta}) = (32.72 \pm 1.27_{stat} \pm 0.70_{syst}) pb. From this we derive the partial width {\Gamma}({\eta}-->{\gamma}{\gamma}) = (520 \pm 20_{stat} \pm 13_{syst}) eV. This is in agreement with the world average and is the most precise measurement to date.Comment: Version accepted by JHE

A new limit on the CP violating decay KS -> 3pi0 with the KLOE experiment

We have carried out a new direct search for the CP violating decay KS -> 3pi0 with 1.7 fb^-1 of e+e- collisions collected by the KLOE detector at the phi-factory DAFNE. We have searched for this decay in a sample of about 5.9 x 10^8 KS KL events tagging the KS by means of the KL interaction in the calorimeter and requiring six prompt photons. With respect to our previous search, the analysis has been improved by increasing of a factor four the tagged sample and by a more effective background rejection of fake KS tags and spurious clusters. We find no candidates in data and simulated background samples, while we expect 0.12 standard model events. Normalizing to the number of KS -> 2pi0 events in the same sample, we set the upper limit on BR(KS -> 3pi0 < 2.6 x 10^-8 at 90% C.L., five times lower than the previous limit. We also set the upper limit on the eta_000 parameter, |eta_000 | < 0.0088 at 90% C.L., improving by a factor two the latest direct measurement.Comment: Accepted for publication in Physics Letters B (15 pages, 13 figures

Measurement of \Gamma(\eta -> \pi^+\pi^-\gamma)/\Gamma(\eta -> \pi^+\pi^-\pi^0) with the KLOE Detector

The ratio R_{\eta}=\Gamma(\eta -> \pi^+\pi^-\gamma)/\Gamma(\eta -> \pi^+\pi^-\pi^0) has been measured by analyzing 22 million \phi \to \eta \gamma decays collected by the KLOE experiment at DA\PhiNE, corresponding to an integrated luminosity of 558 pb^{-1}. The \eta \to \pi^+\pi^-\gamma proceeds both via the \rho resonant contribution, and possibly a non-resonant direct term, connected to the box anomaly. Our result, R_{\eta}= 0.1856\pm 0.0005_{stat} \pm 0.0028_{syst}, points out a sizable contribution of the direct term to the total width. The di-pion invariant mass for the \eta -> \pi^+\pi^-\gamma decay could be described in a model-independent approach in terms of a single free parameter, \alpha. The determined value of the parameter \alpha is \alpha = (1.32 \pm 0.08_{stat} +0.10/-0.09_{syst}\pm 0.02_{theo}) GeV^{-2}Comment: Paper in press, accepted by PL

KLOE results in kaon physics and prospects for KLOE-2

The phi-factory DAPHNE offers a possibility to select pure kaon beams, charged and neutral ones. In particular, neutral kaons from phi->KS KL are produced in pairs and the detection of a KS (KL) tags the presence of a KL (KS). This allows to perform precise measurements of kaon properties by means of KLOE detector. Another advantage of a phi-factory consists in fact that the neutral kaon pairs are produced in a pure quantum state (J^(PC) = 1^(--)), which allowsto investigate CP and CPT symmetries via quantum interference effects, as well as the basic principles of quantum mechanics.A review of the most recent results of the KLOE experiment at DAPHNE using pure kaon beams or via quantum interferometry is presented together with prospects for kaon physics at KLOE-2.Comment: 5 pages, 4 figures, From Phi To Psi 2011 conference, to be published in Nuclear Physics B (Proceedings Supplements

Data acquisition and monitoring for the KLOE detector

none77siThe Data Acquisition system for the KLOE experiment, presently running at the Laboratori Nazionali di Frascati DAPhiNE collider, has been designed to sustain an acquisition throughput of 50 Mbyte/s for an event rate of 10 kHz. its two major components are the front end data readout, based on custom buses, and a complex network of computers and storage devices hosting a set of distributed processes. The end result is a seamless data transport from the readout system to the storage library, accompanied by concurrent on line calibrations and data quality control.openA. ALOISIO; F. AMBROSINO; S. CAVALIERE; F. CEVENINI; C. DI DONATO; A. DORIA; D. FIORE; L. MEROLA; G. PIROZZI; G. SARACINO; M. ANTONELLI; F. BOSSI; P. CIAMBRONE; P. DE SIMONE; S. DELL'AGNELLO; M.L. FERRER; G. FINOCCHIARO; C. FORTI; C. GATTI; S. GIOVANNELLA; W. GRANDEGGER; G. LANFRANCHI; B. MARTINI; W. MEI; S. MISCETTI; M. MOULSON; F. MURTAS; M. PALUTAN; L. PASSALACQUA; F. PELUCCHI; P. SANTANGELO; B. SCIASCIA; I. SFILIGOI; J. SHAN; T. SPADARO; P. VALENTE; Y ZHOU; C. BINI; V. BOCCI; G. CABIBBO; R. CALOI; A. CARDINI; E. DE LUCIA; A. DI DOMENICO; P. GAUZZI; E. PASQUALUCCI; M. PASSASEO; D. PICCA; L. PONTECORVO; E. VALENTE; S. VENEZIANO; P. BRANCHINI; E. GRAZIANI; A. PASSERI; A. FERRARI; E. SPIRITI; C. STANESCU; L. TORTORA; M. CASARSA; G. CATALDI; E. GORINI; M. PRIMAVERA; A. VENTURA; G. DE ROBERTIS; P. GUARNACCIA; A. DENIG; CHEN-CHENG KUO; S. MULLER; B. VALERIANI; S. DI FALCO; M. INCAGLI; G. VENANZONI; R. MESSI; L. PACCIANI; E. SANTOVETTI; J. LEE-FRANZINI; M. MARTEMIANOVA., Aloisio; F., Ambrosino; S., Cavaliere; F., Cevenini; C., DI DONATO; A., Doria; D., Fiore; L., Merola; G., Pirozzi; G., Saracino; M., Antonelli; F., Bossi; P., Ciambrone; P., DE SIMONE; S., Dell'Agnello; M. L., Ferrer; G., Finocchiaro; C., Forti; C., Gatti; S., Giovannella; W., Grandegger; G., Lanfranchi; B., Martini; W., Mei; S., Miscetti; M., Moulson; F., Murtas; M., Palutan; L., Passalacqua; F., Pelucchi; P., Santangelo; B., Sciascia; I., Sfiligoi; J., Shan; T., Spadaro; P., Valente; Y., Zhou; C., Bini; V., Bocci; G., Cabibbo; R., Caloi; A., Cardini; E., DE LUCIA; A., DI DOMENICO; P., Gauzzi; E., Pasqualucci; M., Passaseo; D., Picca; L., Pontecorvo; E., Valente; S., Veneziano; P., Branchini; E., Graziani; A., Passeri; A., Ferrari; E., Spiriti; C., Stanescu; L., Tortora; M., Casarsa; G., Cataldi; Gorini, Edoardo; Primavera, Margherita; Ventura, Andrea; G., DE ROBERTIS; P., Guarnaccia; A., Denig; CHEN CHENG, Kuo; S., Muller; B., Valeriani; S., DI FALCO; M., Incagli; G., Venanzoni; R., Messi; L., Pacciani; E., Santovetti; J., LEE FRANZINI; M., Martemiano

Determination of σ(e+e−→π+π−)\sigma(e^+e^-\to \pi^+ \pi^-) from radiative processes at DAΦ\PhiNE

We have measured the cross section $\sigma(e^+e^-\to\pi^+\pi^-\gamma)$ with the KLOE detector at DA$\Phi$NE, at an energy $W=M_\phi=1.02$ GeV. From the dependence of the cross section on $m(\pi^+\pi^-)=\sqrt{W^2-2WE_\gamma}$, where $E_\gamma$ is the energy of the photon radiated from the initial state, we extract $\sigma(e^+e^-\to\pi^+\pi^-)$ for the mass range $0.35<m^2(\pi^+\pi^-)<0.95$ GeV$^2$. From our result we extract the pion form factor and the hadronic contribution to the muon anomaly, $a_\mu$.Comment: Contributed paper to EPS 2003 and LP 200