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## The WITCH experiment: Acquiring the first recoil ion spectrum

Kozlov, V. Yu.; Beck, M.; Coeck, S.; Delahaye, P.; Friedag, P.; Herbane, M.; Herlert, A.; Kraev, I. S.; Tandecki, M.; Van Gorp, S.; Wauters, F.; Weinheimer, Ch.; Wenander, F.; Zakoucky, D.; Severijns, N.
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.89%
The standard model of the electroweak interaction describes beta-decay in the well-known V-A form. Nevertheless, the most general Hamiltonian of a beta-decay includes also other possible interaction types, e.g. scalar (S) and tensor (T) contributions, which are not fully ruled out yet experimentally. The WITCH experiment aims to study a possible admixture of these exotic interaction types in nuclear beta-decay by a precise measurement of the shape of the recoil ion energy spectrum. The experimental set-up couples a double Penning trap system and a retardation spectrometer. The set-up is installed in ISOLDE/CERN and was recently shown to be fully operational. The current status of the experiment is presented together with the data acquired during the 2006 campaign, showing the first recoil ion energy spectrum obtained. The data taking procedure and corresponding data acquisition system are described in more detail. Several further technical improvements are briefly reviewed.; Comment: 11 pages, 6 figures, conference proceedings EMIS 2007 (http://emis2007.ganil.fr), published also in NIM B: doi:10.1016/j.nimb.2008.05.150

## Highlights from the NA60 experiment

Ferretti, A.; Arnaldi, R.; Averbeck, R.; Banicz, K.; Castor, J.; Chaurand, B.; Cicalò, C.; Colla, A.; Cortese, P.; Damjanovic, S.; David, A.; De Falco, A.; Devaux, A.; Drees, A.; Ducroux, L.; En'yo, H.; Floris, M.; Förster, A.; Force, P.; Guettet, N.; G
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.89%
The NA60 experiment is a fixed-target experiment at the CERN SPS. It has measured the dimuon yield in Indium--Indium collisions with an In beam of 158 AGeV/c and in p-A collisions with a proton beam of 400 and 158 AGeV/c. The results allow to address three important physics topics, namely the study of the rho spectral function in nuclear collisions, the clarification of the origin of the dimuon excess measured by NA50 in the intermediate mass range, and the J/psi suppression pattern in a collision system different from Pb-Pb. An overview of these results will be given in this paper.; Comment: 4 pages, 6 figures, proceeding for the Rencontres de Moriond - QCD and Hadronic interactions - La Thuile (Italy), March 17-24 2007

## First results on double beta decay modes of Cd, Te and Zn isotopes with the COBRA experiment

The COBRA collaboration; Bloxham, T.; Boston, A.; Dawson, J.; Dobos, D.; Fox, S. P.; Freer, M.; Fulton, B. R.; Gößling, C.; Harrison, P. F.; Junker, M.; Kiel, H.; McGrath, J.; Morgan, B.; Münstermann, D.; Nolan, P.; Oehl, S.; Ramachers, Y.; Reeve, C.;
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.89%
Four 1cm^3 CdZnTe semiconductor detectors were operated in the Gran Sasso National Laboratory to explore the feasibility of such devices for double beta decay searches as proposed for the COBRA experiment. The research involved background studies accompanied by measurements of energy resolution performed at the surface. Energy resolutions sufficient to reduce the contribution of two-neutrino double beta decay events to a negligible level for a large scale experiment have already been achieved and further improvements are expected. Using activity measurements of contaminants in all construction materials a background model was developed with the help of Monte Carlo simulations and major background sources were identified. A total exposure of 4.34 kg.days of underground data has been accumulated allowing a search for neutrinoless double beta decay modes of seven isotopes found in CdZnTe. Half-life limits (90% C.L.) are presented for decays to ground and excited states. Four improved lower limits have been obtained, including zero neutrino double electron capture transitions of Zn64 and Te120 to the ground state, which are 1.19*10^{17} years and 2.68*10^{15} years respectively.; Comment: 8 pages, 7 figures

## Electromagnetic emission from hot medium measured by the PHENIX experiment at RHIC

Sakaguchi, Takao; Collaboration, for the PHENIX
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.89%
Electromagnetic radiation has been of interest in heavy ion collisions because they shed light on early stages of the collisions where hadronic probes do not provide direct information since hadronization and hadronic interactions occur later. The latest results on photon measurement from the PHENIX experiment at RHIC reflect thermodynamic properties of the matter produced in the heavy ion collisions. An unexpectedly large positive elliptic flow measured for direct photons can not be explained by any of the current models.; Comment: Talk contributed to Rutherford Centennial Conference, Aug 8-12, 2011, held in Manchester, UK

## Determination of neutrino incoming direction in the CHOOZ experiment and Supernova explosion location by scintillator detectors

Apollonio, M.; Baldini, A.; Bemporad, C.; Caffau, E.; Cei, F.; Declais, Y.; de Kerret, H.; Dieterle, B.; Etenko, A.; Foresti, L.; George, J.; Giannini, G.; Grassi, M.; Kozlov, Y.; Kropp, W.; Kryn, D.; Laiman, M.; Lane, C. E.; Lefievre, B.; Machulin, I.; M
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.89%
The CHOOZ experiment measured the antineutrino flux at a distance of about 1 Km from two nuclear reactors in order to detect possible neutrino oscillations with squared mass differences as low as 10**-3 eV**2 for full mixing. We show that the data analysis of the electron antineutrino events, collected by our liquid scintillation detector, locates the antineutrino source within a cone of half-aperture of about 18 degrees at the 68% C.L.. We discuss the implications of this experimental result for tracking down a supernova explosion.; Comment: Submitted to Physical Review D

## Double Spin Asymmetries of Inclusive Hadron Electroproductions from a Transversely Polarized $^3\rm{He}$ Target

The Jefferson Lab Hall A Collaboration; Zhao, Y. X.; Allada, K.; Aniol, K.; Annand, J. R. M.; Averett, T.; Benmokhtar, F.; Bertozzi, W.; Bradshaw, P. C.; Bosted, P.; Camsonne, A.; Canan, M.; Cates, G. D.; Chen, C.; Chen, J. -P.; Chen, W.; Chirapatpimol, K
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.89%
We report the measurement of beam-target double-spin asymmetries ($A_\text{LT}$) in the inclusive production of identified hadrons, $\vec{e}~$+$~^3\text{He}^{\uparrow}\rightarrow h+X$, using a longitudinally polarized 5.9 GeV electron beam and a transversely polarized $^3\rm{He}$ target. Hadrons ($\pi^{\pm}$, $K^{\pm}$ and proton) were detected at 16$^{\circ}$ with an average momentum $<$$P_h$$>$=2.35 GeV/c and a transverse momentum ($p_{T}$) coverage from 0.60 to 0.68 GeV/c. Asymmetries from the $^3\text{He}$ target were observed to be non-zero for $\pi^{\pm}$ production when the target was polarized transversely in the horizontal plane. The $\pi^{+}$ and $\pi^{-}$ asymmetries have opposite signs, analogous to the behavior of $A_\text{LT}$ in semi-inclusive deep-inelastic scattering.; Comment: Published in PRC (92.015207), nuclear experiment, high-energy experiment

## Experimental Parameters for a Reactor Antineutrino Experiment at Very Short Baselines

Heeger, K. M.; Littlejohn, B. R.; Mumm, H. P.; Tobin, M. N.
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.89%
Reactor antineutrinos are used to study neutrino oscillation, search for signatures of non-standard neutrino interactions, and to monitor reactor operation for safeguard applications. The flux and energy spectrum of reactor antineutrinos can be predicted from the decays of the nuclear fission products. A comparison of recent reactor calculations with past measurements at baselines of 10-100m suggests a 5.7% deficit. Precision measurements of reactor antineutrinos at very short baselines O(1-10 m) can be used to probe this anomaly and search for possible oscillations into sterile neutrino species. This paper studies the experimental requirements for a new reactor antineutrino measurement at very short baselines and calculates the sensitivity of various scenarios. We conclude that an experiment at a typical research reactor provides 5{\sigma} discovery potential for the favored oscillation parameter space with 3 years of data collection.; Comment: 22 pages, 18 figures, 4 tables

## The Qweak Experiment -- A search for new physics at the TeV Scale by measurement of the proton's weak charge

Ramsay, W. D.; Collaboration, for the Qweak
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.89%
From a distance, the proton's weak charge is seen through the distorting effects of clouds of virtual particles. The effective weak charge can be calculated by starting with the measured weak coupling at the Z-pole and "running" the coupling to lower energy or, equivalently, longer distances. Because the "electroweak radiative corrections" or "loop diagrams" which give rise to the running depend not only on known particles, but on particles which have not yet been discovered, a difference between the calculated and measured weak charges may signal new physics. A measurement of Qweak to 4% will be sensitive to new physics at the few TeV scale. The Qweak experiment is based on the fact that the parity-violating longitudinal analyzing power, Az, in electron-proton scattering at low momentum transfer and small scattering angle, is proportional to the proton's weak charge. The experiment plans to measure the predicted Az of -0.3 ppm with a combined statistical and systematic uncertainty of 2.2%, corresponding to a total uncertainty of 4% of Qweak. This requires a statistical precision of 5 x 10^-9, which can be achieved in 2200 hours with an 85% polarized, 180 microamp electron beam incident on a 0.35 m liquid hydrogen target. A synchronous data acquisition system will integrate the detector current signals over each spin state and extract the helicity correlated...

## Recent results on event-by-event fluctuations from the RHIC Beam Energy Scan program in the STAR experiment

Sahoo, Nihar Ranjan
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.89%
Event-by-event fluctuations of global observables in relativistic heavy-ion collisions are studied as probes for the QCD phase transition and as tools to search for critical phenomena near the phase boundary. Dynamical fluctuations in mean transverse momentum, identified particle ratios and conserved quantities (such as net-charge, net-baryon) are expected to provide signatures of a de-confined state of matter. Non-monotonic behavior in the higher-moments of conserved quantities as a function of beam energy and collision centrality are proposed as signatures of the QCD critical point. To study the QCD phase transition and locate the critical point, the STAR experiment at RHIC has collected a large amount of data for Au+Au collisions from $\sqrt{s_{NN}} = 7.7-200$~GeV in the RHIC Beam Energy Scan (BES) program. We present the recent beam energy scan results on dynamical fluctuations of particle ratios and two-particle transverse momentum correlations at mid-rapidity. Higher-moments of the net-charge and net-proton multiplicity distributions as a function of beam energy will be presented. We give a summary of what has been learnt so far and future prospectives for the BES-II program.; Comment: 9 figures, 8 pages; Invited talk presented at the 30th Winter Workshop on Nuclear Dynamics (WWND 2014)...

## Improved Search for $\bar \nu_\mu \rightarrow \bar \nu_e$ Oscillations in the MiniBooNE Experiment

The MiniBooNE Collaboration; Aguilar-Arevalo, A. A.; Brown, B. C.; Bugel, L.; Cheng, G.; Church, E. D.; Conrad, J. M.; Dharmapalan, R.; Djurcic, Z.; Finley, D. A.; Ford, R.; Garcia, F. G.; Garvey, G. T.; Grange, J.; Huelsnitz, W.; Ignarra, C.; Imlay, R.;
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.89%

## Probing the braneworld hypothesis with a neutron-shining-through-a-wall experiment

Sarrazin, Michael; Pignol, Guillaume; Lamblin, Jacob; Petit, Fabrice; Terwagne, Guy; Nesvizhevsky, Valery V.
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.89%
The possibility for our visible world to be a 3-brane embedded in a multidimensional bulk is at the heart of many theoretical edifices in high-energy physics. Probing the braneworld hypothesis is thus a major experimental challenge. Following recent theoretical works showing that matter swapping between braneworlds can occur, we propose a neutron-shining-through-a-wall experiment. We first show that an intense neutron source such as a nuclear reactor core can induce a hidden neutron flux in an adjacent hidden braneworld. We then describe how a low-background detector can detect neutrons arising from the hidden world and quantify the expected sensitivity to the swapping probability. As a proof of concept, a constraint is derived from previous experiments.; Comment: 12 pages, 4 figures, final version published in Physical Review D

## The CLEAR Experiment

Scholberg, K.; Wongjirad, T.; Hungerford, E.; Empl, A.; Markoff, D.; Mueller, P.; Efremenko, Y.; McKinsey, D.; Nikkel, J.