Records |
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Sborlini, G.F.R.; de Florian, D.; Rodrigo, G. |
Title |
Double collinear splitting amplitudes at next-to-leading order |
Type |
Journal Article |
Year |
2014 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
Volume |
01 |
Issue |
1 |
Pages |
018 - 55pp |
Keywords |
NLO Computations; Hadronic Colliders |
Abstract |
We compute the next-to-leading order (NLO) QCD corrections to the 1 -> 2 splitting amplitudes in different dimensional regularization (DREG) schemes. Besides recovering previously known results, we explore new DREG schemes and analyze their consistency by comparing the divergent structure with the expected behavior predicted by Catani's formula. Through the introduction of scalar-gluons, we show the relation among splittings matrices computed using different schemes. Also, we extended this analysis to cover the double collinear limit of scattering amplitudes in the context of QCD+QED. |
Address |
[Sborlini, German F. R.; de Florian, Daniel] Univ Buenos Aires, FCEyN, Dept Fis, RA-1428 Buenos Aires, Argentina, Email: gfsborlini@df.uba.ar; |
Corporate Author |
|
Thesis |
|
Publisher |
Springer |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1029-8479 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000329617800009 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1698 |
Permanent link to this record |
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Sborlini, G.F.R.; de Florian, D.; Rodrigo, G. |
Title |
Triple collinear splitting functions at NLO for scattering processes with photons |
Type |
Journal Article |
Year |
2014 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
Volume |
10 |
Issue |
10 |
Pages |
161 - 29pp |
Keywords |
NLO Computations |
Abstract |
We present splitting functions in the triple collinear limit at next-to-leading order. The computation was performed in the context of massless QCD+QED, considering only processes which include at least one photon. Through the comparison of the IR divergent structure of splitting amplitudes with the expected known behavior, we were able to check our results. Besides that we implemented some consistency checks based on symmetry arguments and cross-checked the results among them. Studying photon-started processes, we obtained very compact results. |
Address |
[Sborlini, German F. R.; de Florian, Daniel] Univ Buenos Aires, FCEyN, Dept Fis, RA-1428 Buenos Aires, DF, Argentina, Email: gfsborlini@df.uba.ar; |
Corporate Author |
|
Thesis |
|
Publisher |
Springer |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1029-8479 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000347905900001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2082 |
Permanent link to this record |
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Scandale, W et al; Lari, L. |
Title |
Deflection of high energy protons by multiple volume reflections in a modified multi-strip silicon deflector |
Type |
Journal Article |
Year |
2014 |
Publication |
Nuclear Instruments & Methods in Physics Research B |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. B |
Volume |
338 |
Issue |
|
Pages |
108-111 |
Keywords |
Accelerator; Beam collimation; Crystal; Channeling; Volume reflection |
Abstract |
The effect of multiple volume reflections in one crystal was observed in each of several bent silicon strips for 400 GeV/c protons. This considerably increased the particle deflections. Some particles were also deflected due to channeling in one of the subsequent strips. As a result, the incident beam was strongly spread because of opposite directions of the deflections. A modified multi-strip deflector produced by periodic grooves on the surface of a thick silicon plate was used for these measurements. This technique provides perfect mutual alignment between crystal strips. Such multi-strip deflector may be effective for collider beam halo collimation and a study is planned at the CERN SPS circulating beam. |
Address |
[Scandale, W.; Arduini, G.; Butcher, M.; Cerutti, F.; Gilardoni, S.; Lari, L.; Lechner, A.; Losito, R.; Masi, A.; Mereghetti, A.; Metral, E.; Mirarchi, D.; Montesano, S.; Redaelli, S.; Schoofs, P.; Smirnov, G.] CERN, European Org Nucl Res, CH-1211 Geneva 23, Switzerland |
Corporate Author |
|
Thesis |
|
Publisher |
Elsevier Science Bv |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0168-583x |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000343390400016 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1974 |
Permanent link to this record |
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Simpson, G.S. et al; Montaner-Piza, A. |
Title |
Yrast 6(+) Seniority Isomers of Sn-136,Sn-138 |
Type |
Journal Article |
Year |
2014 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
113 |
Issue |
13 |
Pages |
132502 - 6pp |
Keywords |
|
Abstract |
Delayed gamma-ray cascades, originating from the decay of (6(+)) isomeric states, in the very neutron-rich, semimagic isotopes Sn-136,Sn-138 have been observed following the projectile fission of a U-238 beam at RIBF, RIKEN. The wave functions of these isomeric states are proposed to be predominantly a fully aligned pair of f(7/2) neutrons. Shell-model calculations, performed using a realistic effective interaction, reproduce well the energies of the excited states of these nuclei and the measured transition rates, with the exception of the B(E2; 6(+) -> 4(+)) rate of Sn-136, which deviates from a simple seniority scheme. Empirically reducing the nu f(7/2)(2) orbit matrix elements produces a 4(1)(+) state with almost equal seniority 2 and 4 components, correctly reproducing the experimental B(E2; 6(+) -> 4(+)) rate of Sn-136. These data provide a key benchmark for shell-model interactions far from stability. |
Address |
[Simpson, G. S.] Univ West Scotland, Sch Engn, Paisley PA1 2BE, Renfrew, Scotland |
Corporate Author |
|
Thesis |
|
Publisher |
Amer Physical Soc |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0031-9007 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000342666500001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1957 |
Permanent link to this record |
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Sorel, M. |
Title |
Expected performance of an ideal liquid argon neutrino detector with enhanced sensitivity to scintillation light |
Type |
Journal Article |
Year |
2014 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
Volume |
9 |
Issue |
|
Pages |
P10002 - 25pp |
Keywords |
Noble liquid detectors (scintillation, ionization, double-phase); Neutrino detectors; Calorimeters; Time projection chambers |
Abstract |
Scintillation light is used in liquid argon (LAr) neutrino detectors to provide a trigger signal, veto information against cosmic rays, and absolute event timing. In this work, we discuss additional opportunities offered by detectors with enhanced sensitivity to scintillation light, that is with light collection efficiencies of about 10(-3). We focus on two key detector performance indicators for neutrino oscillation physics: calorimetric neutrino energy reconstruction and neutrino/antineutrino separation in a non-magnetized detector. Our results are based on detailed simulations, with neutrino interactions modelled according to the GENIE event generator, while the charge and light responses of a large LAr ideal detector are described by the Geant4 and NEST simulation tools. A neutrino energy resolution as good as 3.3% RMS for 4 GeV electron neutrino charged-current interactions can in principle be obtained in a large detector of this type, by using both charge and light information. By exploiting muon capture in argon and scintillation light information to veto muon decay electrons, we also obtain muon neutrino identification efficiencies of about 50%, and muon antineutrino misidentification rates at the few percent level, for few-GeV neutrino interactions that are fully contained. We argue that the construction of large LAr detectors with sufficiently high light collection efficiencies is in principle possible. |
Address |
[Sorel, M.] CSIC, Inst Fis Corpuscular IFIC, Valencia 46980, Spain, Email: sorel@ific.uv.es |
Corporate Author |
|
Thesis |
|
Publisher |
Iop Publishing Ltd |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1748-0221 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000345858500045 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
2056 |
Permanent link to this record |
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Strege, C.; Bertone, G.; Besjes, G.J.; Caron, S.; Ruiz de Austri, R.; Strubig, A.; Trotta, R. |
Title |
Profile likelihood maps of a 15-dimensional MSSM |
Type |
Journal Article |
Year |
2014 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
Volume |
09 |
Issue |
9 |
Pages |
081 - 59pp |
Keywords |
Supersymmetry Phenomenology |
Abstract |
We present statistically convergent profile likelihood maps obtained via global fits of a phenomenological Minimal Supersymmetric Standard Model with 15 free parameters (the MSSM-15), based on over 250M points. We derive constraints on the model parameters from direct detection limits on dark matter, the Planck relic density measurement and data from accelerator searches. We provide a detailed analysis of the rich phenomenology of this model, and determine the SUSY mass spectrum and dark matter properties that are preferred by current experimental constraints. We evaluate the impact of the measurement of the anomalous magnetic moment of the muon (g – 2) on our results, and provide an analysis of scenarios in which the lightest neutralino is a subdominant component of the dark matter. The MSSM-15 parameters are relatively weakly constrained by current data sets, with the exception of the parameters related to dark matter phenomenology (M-1, M-2, mu), which are restricted to the sub-TeV regime, mainly due to the relic density constraint. The mass of the lightest neutralino is found to be < 1.5TeV at 99% C.L., but can extend up to 3 TeV when excluding the g – 2 constraint from the analysis. Low-mass bino-like neutralinos are strongly favoured, with spin-independent scattering cross-sections extending to very small values, similar to 10(-20) pb. ATLAS SUSY null searches strongly impact on this mass range, and thus rule out a region of parameter space that is outside the reach of any current or future direct detection experiment. The best-fit point obtained after inclusion of all data corresponds to a squark mass of 2.3 TeV, a gluino mass of 2.1 TeV and a 130 GeV neutralino with a spin-independent cross-section of 2.4 x 10(-10) pb, which is within the reach of future multi-ton scale direct detection experiments and of the upcoming LHC run at increased centre-of-mass energy. |
Address |
[Strege, C.; Trotta, R.] Univ London Imperial Coll Sci Technol & Med, Imperial Ctr Inference & Cosmol, Blackett Lab, Astrophys Grp, London SW7 2AZ, England, Email: charlotte.strege09@imperial.ac.uk; |
Corporate Author |
|
Thesis |
|
Publisher |
Springer |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1029-8479 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000342069700001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1934 |
Permanent link to this record |
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Stuhl, L.; Krasznahorkay, A.; Csatlos, M.; Algora, A.; Gulyas, J.; Kalinka, G.; Timar, J.; Kalantar-Nayestanaki, N.; Rigollet, C.; Bagchi, S.; Najafi, M.A. |
Title |
A neutron spectrometer for studying giant resonances with (p,n) reactions in inverse kinematics |
Type |
Journal Article |
Year |
2014 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
Volume |
736 |
Issue |
|
Pages |
1-9 |
Keywords |
Low-energy neutron spectrometer; Neutron time-of-flight measurements; ELENS; VM2000 wrapping |
Abstract |
A neutron spectrometer, the European Low-Energy Neutron Spectrometer (ELENS), has been constructed to study exotic nuclei in inverse-kinematics experiments. The spectrometer, which consists of plastic scintillator bars, can be operated in the neutron energy range of 100 keV-10 MeV. The neutron energy is determined using the time-of-flight technique, while the position of the neutron detection is deduced from the time-difference information from photomultipliers attached to both ends of each bar. A novel wrapping method has been developed for the plastic scintillators. The array has a larger than 25% detection efficiency for neutrons of approximately 500 keV in kinetic energy and an angular resolution of less than 1 degrees. Details of the design, construction and experimental tests of the spectrometer will be presented. |
Address |
[Stuhl, L.; Krasznahorkay, A.; Csatlos, M.; Algora, A.; Gulyas, J.; Kalinka, G.; Timar, J.] Hungarian Acad Sci, Inst Nucl Res, ATOMKI, Debrecen, Hungary, Email: stuhl@atomki.hu |
Corporate Author |
|
Thesis |
|
Publisher |
Elsevier Science Bv |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0168-9002 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000329404000002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1695 |
Permanent link to this record |
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
T2K Collaboration (Abe, K. et al); Cervera-Villanueva, A.; Escudero, L.; Gomez-Cadenas, J.J.; Izmaylov, A.; Monfregola, L.; Sorel, M.; Stamoulis, P. |
Title |
Observation of Electron Neutrino Appearance in a Muon Neutrino Beam |
Type |
Journal Article |
Year |
2014 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
112 |
Issue |
6 |
Pages |
061802 - 8pp |
Keywords |
|
Abstract |
The T2K experiment has observed electron neutrino appearance in a muon neutrino beam produced 295 km from the Super-Kamiokande detector with a peak energy of 0.6 GeV. A total of 28 electron neutrino events were detected with an energy distribution consistent with an appearance signal, corresponding to a significance of 7.3 sigma when compared to 4.92 +/- 0.55 expected background events. In the Pontecorvo-Maki-Nakagawa-Sakata mixing model, the electron neutrino appearance signal depends on several parameters including three mixing angles theta(12), theta(23), theta(13), a mass difference vertical bar Delta m(32)(2)vertical bar and a CP violating phase delta(CP). In this neutrino oscillation scenario, assuming vertical bar Delta m(32)(2)vertical bar = 2.4 x 10(-3) eV(2), sin theta(2)(23) = 0.5, and vertical bar Delta m(32)(2)vertical bar > 0 (vertical bar Delta m(32)(2)vertical bar < 0), a best- fit value of sin2 theta(2)(13) = 0.140(- 0.032)(+0.038) (0.170(-0.037)(+0.045)) is obtained at delta(CP) = 0. When combining the result with the current best knowledge of oscillation parameters including the world average value of theta(13) from reactor experiments, some values of delta(CP) are disfavored at the 90% C. L. |
Address |
[Kitching, P.] Univ Alberta, Dept Phys, Ctr Particle Phys, Edmonton, AB, Canada |
Corporate Author |
|
Thesis |
|
Publisher |
Amer Physical Soc |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0031-9007 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000331951000003 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1701 |
Permanent link to this record |
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
T2K Collaboration (Abe, K. et al); Cervera-Villanueva, A.; Escudero, L.; Gomez-Cadenas, J.J.; Izmaylov, A.; Monfregola, L.; Sorel, M.; Stamoulis, P. |
Title |
Measurement of the intrinsic electron neutrino component in the T2K neutrino beam with the ND280 detector |
Type |
Journal Article |
Year |
2014 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
89 |
Issue |
9 |
Pages |
092003 - 18pp |
Keywords |
|
Abstract |
The T2K experiment has reported the first observation of the appearance of electron neutrinos in a muon neutrino beam. The main and irreducible background to the appearance signal comes from the presence in the neutrino beam of a small intrinsic component of electron neutrinos originating from muon and kaon decays. In T2K, this component is expected to represent 1.2% of the total neutrino flux. A measurement of this component using the near detector (ND280), located 280 m from the target, is presented. The charged current interactions of electron neutrinos are selected by combining the particle identification capabilities of both the time projection chambers and electromagnetic calorimeters of ND280. The measured ratio between the observed electron neutrino beam component and the prediction is 1.01 +/- 0.10 providing a direct confirmation of the neutrino fluxes and neutrino cross section modeling used for T2K neutrino oscillation analyses. Electron neutrinos coming from muons and kaons decay are also separately measured, resulting in a ratio with respect to the prediction of 0.68 +/- 0.30 and 1.10 +/- 0.14, respectively. |
Address |
[Kitching, P.] Univ Alberta, Dept Phys, Ctr Particle Phys, Edmonton, AB, Canada |
Corporate Author |
|
Thesis |
|
Publisher |
Amer Physical Soc |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1550-7998 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000336102000002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1796 |
Permanent link to this record |
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
T2K Collaboration (Abe, K. et al); Cervera-Villanueva, A.; Escudero, L.; Gomez-Cadenas, J.J.; Izmaylov, A.; Monfregola, L.; Sorel, M.; Stamoulis, P. |
Title |
Measurement of the neutrino-oxygen neutral-current interaction cross section by observing nuclear deexcitation gamma rays |
Type |
Journal Article |
Year |
2014 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
90 |
Issue |
7 |
Pages |
072012 - 11pp |
Keywords |
|
Abstract |
We report the first measurement of the neutrino-oxygen neutral-current quasielastic (NCQE) cross section gamma It is obtained by observing nuclear deexcitation. rays which follow neutrino-oxygen interactions at the Super-Kamiokande water Cherenkov detector. We use T2K data corresponding to 3.01 x 10(20) protons on target. By selecting only events during the T2K beam window and with well-reconstructed vertices in the fiducial volume, the large background rate from natural radioactivity is dramatically reduced. We observe 43 events in the 4-30 MeV reconstructed energy window, compared with an expectation of 51.0, which includes an estimated 16.2 background events. The background is primarily nonquasielastic neutral-current interactions and has only 1.2 events from natural radioactivity. The flux-averaged NCQE cross section we measure is 1.55 x 10(-38) cm(2) with a 68% confidence interval of (1.22, 2.20) x 10(-38) cm(2) at a median neutrino energy of 630 MeV, compared with the theoretical prediction of 2.01 x 10(-38) cm(2). |
Address |
[Kitching, P.] Univ Alberta, Dept Phys, Ctr Particle Phys, Edmonton, AB, Canada |
Corporate Author |
|
Thesis |
|
Publisher |
Amer Physical Soc |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1550-7998 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000344033100001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1993 |
Permanent link to this record |