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Author Liem, S.; Bertone, G.; Calore, F.; Ruiz de Austri, R.; Tait, T.M.P.; Trotta, R.; Weniger, C.
Title Effective field theory of dark matter: a global analysis Type Journal Article
Year 2016 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 09 Issue 9 Pages 077 - 22pp
Keywords Beyond Standard Model; Cosmology of Theories beyond the SM; Effective field theories
Abstract We present global fits of an effective field theory description of real, and complex scalar dark matter candidates. We simultaneously take into account all possible dimension 6 operators consisting of dark matter bilinears and gauge invariant combinations of quark and gluon fields. We derive constraints on the free model parameters for both the real (five parameters) and complex (seven) scalar dark matter models obtained by combining Planck data on the cosmic microwave background, direct detection limits from LUX, and indirect detection limits from the Fermi Large Area Telescope. We find that for real scalars indirect dark matter searches disfavour a dark matter particle mass below 100 GeV. For the complex scalar dark matter particle current data have a limited impact due to the presence of operators that lead to p-wave annihilation, and also do not contribute to the spin-independent scattering cross-section. Although current data are not informative enough to strongly constrain the theory parameter space, we demonstrate the power of our formalism to reconstruct the theoretical parameters compatible with an actual dark matter detection, by assuming that the excess of gamma rays observed by the Fermi Large Area Telescope towards the Galactic centre is entirely due to dark matter annihilations. Please note that the excess can very well be due to astrophysical sources such as millisecond pulsars. We find that scalar dark matter interacting via effective field theory operators can in principle explain the Galactic centre excess, but that such interpretation is in strong tension with the non-detection of gamma rays from dwarf galaxies in the real scalar case. In the complex scalar case there is enough freedom to relieve the tension.
Address [Liem, Sebastian; Bertone, Gianfranco; Calore, Francesca; Weniger, Christoph] Univ Amsterdam, GRAPPA, Sci Pk 904, NL-1098 XH Amsterdam, Netherlands, Email: sebastian.liem@uva.nl;
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 (up) Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000383545500003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2864
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Author Brzezinski, K.; Oliver, J.F.; Gillam, J.; Rafecas, M.; Studen, A.; Grkovski, M.; Kagan, H.; Smith, S.; Llosa, G.; Lacasta, C.; Clinthorne, N.H.
Title Experimental evaluation of the resolution improvement provided by a silicon PET probe Type Journal Article
Year 2016 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 11 Issue Pages P09016 - 13pp
Keywords Gamma camera; SPECT; PET PET/CT; coronary CT angiography (CTA); Medical-image reconstruction methods and algorithms; computer-aided software
Abstract A high-resolution PET system, which incorporates a silicon detector probe into a conventional PET scanner, has been proposed to obtain increased image quality in a limited region of interest. Detailed simulation studies have previously shown that the additional probe information improves the spatial resolution of the reconstructed image and increases lesion detectability, with no cost to other image quality measures. The current study expands on the previous work by using a laboratory prototype of the silicon PET-probe system to examine the resolution improvement in an experimental setting. Two different versions of the probe prototype were assessed, both consisting of a back-to-back pair of 1-mm thick silicon pad detectors, one arranged in 32 x 16 arrays of 1.4mm x 1.4mm pixels and the other in 40 x 26 arrays of 1.0mm x 1.0mm pixels. Each detector was read out by a set of VATAGP7 ASICs and a custom-designed data acquisition board which allowed trigger and data interfacing with the PET scanner, itself consisting of BGO block detectors segmented into 8 x 6 arrays of 6mm x 12mm x 30mm crystals. Limited-angle probe data was acquired from a group of Na-22 point-like sources in order to observe the maximum resolution achievable using the probe system. Data from a Derenzo-like resolution phantom was acquired, then scaled to obtain similar statistical quality as that of previous simulation studies. In this case, images were reconstructed using measurements of the PET ring alone and with the inclusion of the probe data. Images of the Na-22 source demonstrated a resolution of 1.5mm FWHM in the probe data, the PET ring resolution being approximately 6 mm. Profiles taken through the image of the Derenzo-like phantom showed a clear increase in spatial resolution. Improvements in peak-to-valley ratios of 50% and 38%, in the 4.8mm and 4.0mm phantom features respectively, were observed, while previously unresolvable 3.2mm features were brought to light by the addition of the probe. These results support the possibility of improving the image resolution of a clinical PET scanner using the silicon PET-probe.
Address [Brzezinski, K.; Oliver, J. F.; Gillam, J.; Rafecas, M.; Llosa, G.; Lacasta, C.] Univ Valencia, CSIC, Inst Fis Corpuscular, C Catedrat Jose Beltran 2, Valencia, Spain, Email: k.w.brzezinski@rug.nl
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 (up) Edition
ISSN 1748-0221 ISBN Medium
Area Expedition Conference
Notes WOS:000387862300016 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2865
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Author Gomez-Cadenas, J.J.; Benlloch-Rodriguez, J.M.; Ferrario, P.; Monrabal, F.; Rodriguez, J.; Toledo, J.F.
Title Investigation of the coincidence resolving time performance of a PET scanner based on liquid xenon: a Monte Carlo study Type Journal Article
Year 2016 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 11 Issue Pages P09011 - 18pp
Keywords Gamma camera; SPECT; PET PET/CT; coronary CT angiography (CTA); Instrumentation and methods for time-of-flight (TOF) spectroscopy; Noble liquid detectors (scintillation ionization, double-phase); Scintillators; scintillation and light emission processes (solid, gas and liquid scintillators)
Abstract The measurement of the time of flight of the two 511 keV gammas recorded in coincidence in a PET scanner provides an effective way of reducing the random background and therefore increases the scanner sensitivity, provided that the coincidence resolving time (CRT) of the gammas is sufficiently good. The best commercial PET-TOF system today (based in LYSO crystals and digital SiPMs), is the VEREOS of Philips, boasting a CRT of 316 ps (FWHM). In this paper we present a Monte Carlo investigation of the CRT performance of a PET scanner exploiting the scintillating properties of liquid xenon. We find that an excellent CRT of 70 ps (depending on the PDE of the sensor) can be obtained if the scanner is instrumented with silicon photomultipliers (SiPMs) sensitive to the ultraviolet light emitted by xenon. Alternatively, a CRT of 160 ps can be obtained instrumenting the scanner with (much cheaper) blue-sensitive SiPMs coated with a suitable wavelength shifter. These results show the excellent time of flight capabilities of a PET device based in liquid xenon.
Address [Gomez-Cadenas, J. J.; Benlloch-Rodriguez, J. M.; Ferrario, P.; Rodriguez, J.] CSIC, Inst Fis Corpuscular IFIC, Calle Catedrat Jose Beltran 2, Valencia 46980, Spain, Email: paola.ferrario@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 (up) Edition
ISSN 1748-0221 ISBN Medium
Area Expedition Conference
Notes WOS:000387862300011 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2866
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Author Ayala, C.; Gonzalez, P.; Vento, V.
Title Heavy quark potential from QCD-related effective coupling Type Journal Article
Year 2016 Publication Journal of Physics G Abbreviated Journal J. Phys. G
Volume 43 Issue 12 Pages 125002 - 12pp
Keywords general properties of QCD; potential models; other non-perturbative calculations; heavy quarkonia
Abstract We implement our past investigations of quark-antiquark interaction through a non-perturbative running coupling defined in terms of a gluon mass function, similar to that used in some Schwinger-Dyson approaches. This coupling leads to a quark-antiquark potential, which satisfies not only asymptotic freedom but also describes linear confinement correctly. From this potential, we calculate the bottomonium and charmonium spectra below the first open flavor meson-meson thresholds and show that for a small range of values of the free parameter determining the gluon mass function an excellent agreement with data is attained.
Address [Gonzalez, Pedro] Univ Valencia, Dept Theoret Phys, E-46100 Valencia, Spain, Email: Pedro.Gonzalez@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 (up) Edition
ISSN 0954-3899 ISBN Medium
Area Expedition Conference
Notes WOS:000388219700001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 2870
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Author Poley, L. et al; Lacasta, C.; Soldevila, U.
Title Characterisation of strip silicon detectors for the ATLAS Phase-II Upgrade with a micro-focused X-ray beam Type Journal Article
Year 2016 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 11 Issue Pages P07023 - 12pp
Keywords Inspection with x-rays; Si microstrip and pad detectors; Hybrid detectors; Instrumentation for particle accelerators and storage rings – high energy (linear accelerators, synchrotrons)
Abstract The planned HL-LHC (High Luminosity LHC) in 2025 is being designed to maximise the physics potential through a sizable increase in the luminosity up to 6.10(34) cm(-2) s(-1). A consequence of this increased luminosity is the expected radiation damage at 3000 fb(-1) after ten years of operation, requiring the tracking detectors to withstand fluences to over 1.10(16) 1 MeV n(eq)/cm(2) . In order to cope with the consequent increased readout rates, a complete re-design of the current ATLAS Inner Detector (ID) is being developed as the Inner Tracker (ITk). Two proposed detectors for the ATLAS strip tracker region of the ITk were characterized at the Diamond Light Source with a 3 μm FWHM 15 keV micro focused X-ray beam. The devices under test were a 320 μm thick silicon stereo (Barrel) ATLAS12 strip mini sensor wire bonded to a 130 nm CMOS binary readout chip (ABC130) and a 320 μm thick full size radial (end-cap) strip sensor – utilizing bi-metal readout layers – wire bonded to 250 nm CMOS binary readout chips (ABCN-25). A resolution better than the inter strip pitch of the 74.5 μm strips was achieved for both detectors. The effect of the p-stop diffusion layers between strips was investigated in detail for the wire bond pad regions. Inter strip charge collection measurements indicate that the effective width of the strip on the silicon sensors is determined by p-stop regions between the strips rather than the strip pitch.
Address [Poley, L.; Bloch, I.; Diez, S.; Gregor, I. -M.; Lohwasser, K.] DESY, Notkestr, Hamburg, Germany, Email: Anne-Luise.Poley@desy.de
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 (up) Edition
ISSN 1748-0221 ISBN Medium
Area Expedition Conference
Notes WOS:000387763000014 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2872
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Author Lopez-Honorez, L.; Mena, O.; Moline, A.; Palomares-Ruiz, S.; Vincent, A.C.
Title The 21 cm signal and the interplay between dark matter annihilations and astrophysical processes Type Journal Article
Year 2016 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 08 Issue 8 Pages 004 - 40pp
Keywords dark matter theory; intergalactic media; reionization
Abstract Future dedicated radio interferometers, including HERA and SKA, are very promising tools that aim to study the epoch of reionization and beyond via measurements of the 21 cm signal from neutral hydrogen. Dark matter (DM) annihilations into charged particles change the thermal history of the Universe and, as a consequence, affect the 21 cm signal. Accurately predicting the effect of DM strongly relies on the modeling of annihilations inside halos. In this work, we use up-to-date computations of the energy deposition rates by the products from DM annihilations, a proper treatment of the contribution from DM annihilations in halos, as well as values of the annihilation cross section allowed by the most recent cosmological measurements from the Planck satellite. Given current uncertainties on the description of the astrophysical processes driving the epochs of reionization, X-ray heating and Lyman-alpha pumping, we find that disentangling DM signatures from purely astrophysical effects, related to early-time star formation processes or late-time galaxy X-ray emissions, will be a challenging task. We conclude that only annihilations of DM particles with masses of similar to 100 MeV, could leave an unambiguous imprint on the 21 cm signal and, in particular, on the 21cm power spectrum. This is in contrast to previous, more optimistic results in the literature, which have claimed that strong signatures might also be present even for much higher DM masses. Additional measurements of the 21cm signal at different cosmic epochs will be crucial in order to break the strong parameter degeneracies between DM annihilations and astrophysical effects and undoubtedly single out a DM imprint for masses different from similar to 100 MeV.
Address [Lopez-Honorez, Laura] Vrije Univ Brussel, Theoret Natuurkunde, Pl Laan 2, B-1050 Brussels, Belgium, Email: llopezho@vub.ac.be;
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 (up) Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000389859100050 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2899
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Author Moline, A.; Schewtschenko, J.A.; Palomares-Ruiz, S.; Boehm, C.; Baugh, C.M.
Title Isotropic extragalactic flux from dark matter annihilations: lessons from interacting dark matter scenarios Type Journal Article
Year 2016 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 08 Issue 8 Pages 069 - 23pp
Keywords dark matter simulations; dark matter theory; gamma ray theory
Abstract The extragalactic gamma-ray and neutrino emission may have a contribution from dark matter (DM) annihilations. In the case of discrepancies between observations and standard predictions, one could infer the DM pair annihilation cross section into cosmic rays by studying the shape of the energy spectrum. So far all analyses of the extragalactic DM signal have assumed the standard cosmological model (ACDM) as the underlying theory. However, there are alternative DM scenarios where the number of low-mass objects is significantly suppressed. Therefore the characteristics of the gamma-ray and neutrino emission in these models may differ from ACDM as a result. Here we show that the extragalactic isotropic signal in these alternative models has a similar energy dependence to that in ACDM, but the overall normalisation is reduced. The similarities between the energy spectra combined with the flux suppression could lead one to misinterpret possible evidence for models beyond ACDM as being due to CDM particles annihilating with a much weaker cross section than expected.
Address [Moline, Angeles] Univ Tecn Lisboa, Inst Super Tecn, CFTP, Av Rovisco Pais 1, P-1049001 Lisbon, Portugal, Email: maria.moline@ist.utl.pt;
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 (up) Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000389859100053 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2900
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Author Fuentes-Martin, J.; Portoles, J.; Ruiz-Femenia, P.
Title Integrating out heavy particles with functional methods: a simplified framework Type Journal Article
Year 2016 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 09 Issue 9 Pages 156 - 26pp
Keywords Effective field theories; Beyond Standard Model
Abstract We present a systematic procedure to obtain the one-loop low-energy effective Lagrangian resulting from integrating out the heavy fields of a given ultraviolet theory. We show that the matching coefficients are determined entirely by the hard region of the functional determinant involving the heavy fields. This represents an important simplification with respect the conventional matching approach, where the full and effective theory contributions have to be computed separately and a cancellation of the infrared divergent parts has to take place. We illustrate the method with a descriptive toy model and with an extension of the Standard Model with a heavy real scalar triplet. A comparison with other schemes that have been put forward recently is also provided.
Address [Fuentes-Martin, Javier; Portoles, Jorge] Univ Politecn Valencia, CSIC, Inst Fis Corpuscular, Apt Correus 22085, E-46071 Valencia, Spain, Email: Javier.Fuentes@ific.uv.es;
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 (up) Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000391735900003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2926
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Author Athenodorou, A.; Binosi, D.; Boucaud, P.; De Soto, F.; Papavassiliou, J.; Rodriguez-Quintero, J.; Zafeiropoulos, S.
Title On the zero crossing of the three-gluon vertex Type Journal Article
Year 2016 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 761 Issue Pages 444-449
Keywords Lattice simulations; Three-gluon vertex; Zero crossing; Schwinger-Dyson equations
Abstract We report on new results on the infrared behavior of the three-gluon vertex in quenched Quantum Chromodynamics, obtained from large-volume lattice simulations. The main focus of our study is the appearance of the characteristic infrared feature known as 'zero crossing', the origin of which is intimately connected with the nonperturbative masslessness of the Faddeev-Popov ghost. The appearance of this effect is clearly visible in one of the two kinematic configurations analyzed, and its theoretical origin is discussed in the framework of Schwinger-Dyson equations. The effective coupling in the momentum subtraction scheme that corresponds to the three-gluon vertex is constructed, revealing the vanishing of the effective interaction at the exact location of the zero crossing.
Address [Athenodorou, A.] Univ Cyprus, Dept Phys, POB 20537, CY-1678 Nicosia, Cyprus, Email: binosi@ectstar.eu
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 (up) Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000384469900063 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2939
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Author Bertone, G.; Calore, F.; Caron, S.; Ruiz de Austri, R.; Kim, J.S.; Trotta, R.; Weniger, C.
Title Global analysis of the pMSSM in light of the Fermi GeV excess: prospects for the LHC Run-II and astroparticle experiments Type Journal Article
Year 2016 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 04 Issue 4 Pages 037 - 20pp
Keywords dark matter detectors; dark matter theory; gamma ray experiments; supersymmetry and cosmology
Abstract We present a new global fit of the 19-dimensional phenomenological Minimal Supersymmetric Standard Model (pMSSM-19) that complies with all the latest experimental results from dark matter indirect, direct and accelerator dark matter searches. We show that the model provides a satisfactory explanation of the excess of gamma rays from the Galactic centre observed by the Fermi Large Area Telescope, assuming that it is produced by the annihilation of neutralinos in the Milky Way halo. We identify two regions that pass all the constraints: the first corresponds to neutralinos with a mass similar to 80 – 100 GeV annihilating into WW with a branching ratio of 95%; the second to heavier neutralinos, with mass similar to 180 – 200 GeV annihilating into (l) over barl with a branching ratio of 87%. We show that neutralinos compatible with the Galactic centre GeV excess will soon be within the reach of LHC run-II – notably through searches for charginos and neutralinos, squarks and light smuons – and of Xenon1T, thanks to its unprecedented sensitivity to spin-dependent cross-section off neutrons.
Address [Bertone, Gianfranco; Calore, Francesca; Weniger, Christoph] Univ Amsterdam, GRAPPA, Sci Pk 904, NL-1090 GL Amsterdam, Netherlands, Email: gf.bertone@gmail.com;
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 (up) Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000393286400010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2951
Permanent link to this record