Records |
Author |
BABAR Collaboration (del Amo Sanchez, P. et al); Lopez-March, N.; Martinez-Vidal, F.; Oyanguren, A. |
Title |
Search for Production of Invisible Final States in Single-Photon Decays of Gamma(1S) |
Type |
Journal Article |
Year |
2011 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
107 |
Issue |
2 |
Pages |
021804 - 7pp |
Keywords |
|
Abstract |
We search for single-photon decays of the Gamma(1S) resonance, Gamma -> gamma + invisible, where the invisible state is either a particle of definite mass, such as a light Higgs boson A(0), or a pair of dark matter particles, chi(chi) over bar. Both A(0) and chi are assumed to have zero spin. We tag Gamma(1S) decays with a dipion transition Gamma(1S) -> pi(+)pi(-)Y(1S) and look for events with a single energetic photon and significant missing energy. We find no evidence for such processes in the mass range m(A0) <= 9.2 GeV and m(chi) <= 4.5 GeV in the sample of 98 x 10(6) Gamma(2S) decays collected with the BABAR detector and set stringent limits on new physics models that contain light dark matter states. |
Address |
[Sanchez, PD; Lees, JP; Poireau, V; Prencipe, E; Tisserand, V] Univ Savoie, CNRS, Lab Annecy Le Vieux Phys Particules LAPP, IN2P3, F-74941 Annecy Le Vieux, France |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0031-9007 |
ISBN |
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Medium |
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Area |
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Expedition |
|
Conference |
|
Notes |
WOS:000292516600008 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
691 |
Permanent link to this record |
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Author |
BABAR Collaboration (del Amo Sanchez, P. et al); Lopez-March, N.; Martinez-Vidal, F.; Milanes, D.A.; Oyanguren, A. |
Title |
Observation of eta(c) (1S) and eta(c) (2S) decays to K(+)K(-) pi(+) pi(-) pi(0) in two-photon interactions |
Type |
Journal Article |
Year |
2011 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
84 |
Issue |
1 |
Pages |
012004 - 9pp |
Keywords |
|
Abstract |
We study the processes gamma gamma -> K(S)(0) K(-+) pi(-+) and gamma gamma -> K(+)K(-) pi(+)pi(-)pi(0) using a data sample of 519: 2fb(-1) recorded by the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider at center-of-mass energies near the Y(nS) (n = 2, 3, 4) resonances. We observe the eta(c) (1S), chi(c0) (1P) and eta(c) (2S) resonances produced in two-photon interactions and decaying to K(+)K(-) pi(+)pi(-)pi(0), with significances of 18.1, 5.4 and 5.3 standard deviations (including systematic errors), respectively, and report 4.0 sigma evidence of the X(c2)(1P) decay to this final state. We measure the eta(c)(2S) mass and width in K(S)(0) K(+-) pi(+-) decays, and obtain the values m(eta(c)(2S)) = 3638: 5 +/- 1.5 +/- 0.8 MeV/c(2) and Gamma(eta(c)(2S)) = 13.4 +/- 4: 6 +/- 3.2 MeV, where the first uncertainty is statistical and the second is systematic. We measure the two-photon width times branching fraction for the reported resonance signals, and search for the X(c2) (2P) resonance, but no significant signal is observed. |
Address |
[Sanchez, PD; Lees, JP; Poireau, V; Prencipe, E; Tisserand, V] Univ Savoie, Lab Annecy Le Vieux Phys Particules, CNRS, IN2P3, F-74941 Annecy Le Vieux, France |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1550-7998 |
ISBN |
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Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000292768900001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
688 |
Permanent link to this record |
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Author |
BABAR Collaboration (del Amo Sanchez, P. et al); Lopez-March, N.; Martinez-Vidal, F.; Oyanguren, A. |
Title |
Measurement of the gamma gamma* -> eta and gamma gamma* -> eta ' transition form factors |
Type |
Journal Article |
Year |
2011 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
84 |
Issue |
5 |
Pages |
052001 - 19pp |
Keywords |
|
Abstract |
We study the reactions e(+)e(-) --> e(+)e(-) eta((')) in the single-tag mode and measure the gamma gamma* --> eta((')) transition form factors in the momentum-transfer range from 4 to 40 GeV(2). The analysis is based on 469 fb(-1) of integrated luminosity collected at PEP-II with the BABAR detector at e(+)e(-) center-of-mass energies near 10.6 GeV. |
Address |
[Sanchez, PD; Lees, JP; Poireau, V; Prencipe, E; Tisserand, V] USAUniv Savoie, LAPP, CNRS, IN2P3, F-74941 Annecy Le Vieux, France |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1550-7998 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
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Conference |
|
Notes |
WOS:000294567400003 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
727 |
Permanent link to this record |
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Author |
n_TOF Collaboration (Sarmento, R. et al); Domingo-Pardo, C.; Tain, J.L. |
Title |
Measurement of the (236)U(n, f) cross section from 170 meV to 2 MeV at the CERN n_TOF facility |
Type |
Journal Article |
Year |
2011 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
84 |
Issue |
4 |
Pages |
044618 - 10pp |
Keywords |
|
Abstract |
The neutron-induced fission cross section of (236)U was measured at the neutron Time-of-Flight (nTOF) facility at CERN relative to the standard (235)U(n, f) cross section for neutron energies ranging from above thermal to several MeV. The measurement, covering the full range simultaneously, was performed with a fast ionization chamber, taking advantage of the high resolution of the nTOF spectrometer. The n_TOF results confirm that the first resonance at 5.45 eV is largely overestimated in some nuclear data libraries. The resonance triplet around 1.2 keV was measured with high resolution and resonance parameters were determined with good accuracy. Resonances at high energy have also been observed and characterized and different values for the cross section are provided for the region between 10 keV and the fission threshold. The present work indicates various shortcomings of the current nuclear data libraries in the subthreshold region and provides the basis for an accurate re-evaluation of the (236)U(n, f) cross section, which is of great relevance for the development of emerging or innovative nuclear reactor technologies. |
Address |
[Sarmento, R; Goncalves, IF; Vaz, P; Carrapico, C; de Albornoz, AC; Marques, L; Salgado, J; Tavora, L] ITN, Sacavem, Portugal |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0556-2813 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000296521000006 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
818 |
Permanent link to this record |
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Author |
Schwetz, T.; Tortola, M.; Valle, J.W.F. |
Title |
Global neutrino data and recent reactor fluxes: the status of three-flavour oscillation parameters |
Type |
Journal Article |
Year |
2011 |
Publication |
New Journal of Physics |
Abbreviated Journal |
New J. Phys. |
Volume |
13 |
Issue |
|
Pages |
063004 - 15pp |
Keywords |
|
Abstract |
We present the results of a global neutrino oscillation data analysis within the three-flavour framework. We include the latest results from the MINOS long-baseline experiment (including electron neutrino appearance and anti-neutrino data), updating all relevant solar (Super-Kamiokande (SK) II + III), atmospheric (SK I + II + III) and reactor (KamLAND) data. Furthermore, we include a recent re-calculation of the anti-neutrino fluxes emitted from nuclear reactors. These results have important consequences for the analysis of reactor experiments and in particular for the status of the mixing angle theta(13). In our recommended default analysis, we find from the global fit that the hint for nonzero theta(13) remains weak, at 1.8 sigma for both neutrino mass hierarchy schemes. However, we discuss in detail the dependence of these results on assumptions regarding the reactor neutrino analysis. |
Address |
[Schwetz, Thomas] Max Planck Inst Kernphys, D-69029 Heidelberg, Germany, Email: schwetz@mpi-hd.mpg.de |
Corporate Author |
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Thesis |
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Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1367-2630 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000292137500004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
666 |
Permanent link to this record |