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Author Bordes, J.; Dominguez, C.A.; Moodley, P.; Peñarrocha, J.; Schilcher, K.
Title (up) Chiral corrections to the SU(2) x SU(2) Gell-Mann-Oakes-Renner relation Type Journal Article
Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 05 Issue 5 Pages 064 - 16pp
Keywords QCD Phenomenology
Abstract The next to leading order chiral corrections to the SU(2) x SU(2) Gell-Mann-Oakes- Renner (GMOR) relation are obtained using the pseudoscalar correlator to five-loop order in perturbative QCD, together with new finite energy sum rules (FESR) incorporating polynomial, Legendre type, integration kernels. The purpose of these kernels is to suppress hadronic contributions in the region where they are least known. This reduces considerably the systematic uncertainties arising from the lack of direct experimental information on the hadronic resonance spectral function. Three different methods are used to compute the FESR contour integral in the complex energy (squared) s-plane, i.e. Fixed Order Perturbation Theory, Contour Improved Perturbation Theory, and a fixed renormalization scale scheme. We obtain for the corrections to the GMOR relation, delta(pi), the value delta(pi) = (6.2 +/- 1.6)%. This result is substantially more accurate than previous determinations based on QCD sum rules; it is also more reliable as it is basically free of systematic uncertainties. It implies a light quark condensate < 0 vertical bar(u) over baru vertical bar 0 > similar or equal to < 0 vertical bar(d) over bard vertical bar 0 > < 0 vertical bar(q) over barq vertical bar 0 >vertical bar(2GeV) = (-267 +/- 5MeV)(3). As a byproduct, the chiral perturbation theory (unphysical) low energy constant H-2(r) is predicted to be H-2(r)(nu(X) = M-p) = -(5.1 +/- 1.8) x10(-3), or H-2(r) (nu(X) = M-eta) = -(5.7 +/- 2.0) x10(-3).
Address [Bordes, J.; Penarrocha, J.] Univ Valencia, Dept Fis Teor, CSICE, E-46100 Burjassot, Spain, Email: bordes@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 Edition
ISSN 1126-6708 ISBN Medium
Area Expedition Conference
Notes ISI:000278250000044 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 434
Permanent link to this record
 
 
Author Hiller Blin, A.N.; Ledwig, T.; Vicente Vacas, M.J.
Title (up) Chiral dynamics in the (gamma)over-right-arrowp -> p pi(0) reaction Type Journal Article
Year 2015 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 747 Issue Pages 217-222
Keywords
Abstract We investigate the neutral pion photoproduction on the proton near threshold in covariant chiral perturbation theory with the explicit inclusion of A degrees of freedom. This channel is specially sensitive to chiral dynamics and the advent of very precise data from the Mainz microtron has shown the limits of the convergence of the chiral series for both the heavy baryon and the covariant approaches. We show that the inclusion of the Delta resonance substantially improves the convergence leading to a good agreement with data for a wider range of energies.
Address [Vicente Vacas, M. J.] Univ Valencia, Ctr Mixto, CSIC, Dept Fis Teor,Inst Invest Paterna, E-46071 Valencia, Spain, Email: manuel.j.vicente@uv.es
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 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000358624800038 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 2330
Permanent link to this record
 
 
Author Bernard, V.; Passemar, E.
Title (up) Chiral extrapolation of the strangeness changing scalar K pi form factor Type Journal Article
Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 04 Issue 4 Pages 001 - 18pp
Keywords Lattice QCD; Chiral Lagrangians
Abstract We perform a chiral extrapolation of lattice data on the scalar K pi form factor and the ratio of the kaon and pion decay constants within Chiral Perturbation Theory to two loops. We determine the value of the scalar form factor at zero momentum transfer, at the Callan-Treiman point and at its soft kaon analog as well as its slope. Results are in good agreement with their determination from experiment using the standard couplings of quarks to the W boson. The slope is however rather large. A study of the convergence of the chiral expansion is also performed.
Address [Bernard, Veronique] Univ Paris 11, Grp Phys Theor, IPN, CNRS, F-91406 Orsay, France, Email: bernard@ipno.in2p3.fr
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 1126-6708 ISBN Medium
Area Expedition Conference
Notes ISI:000277473100070 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 456
Permanent link to this record
 
 
Author Oset, E.; Ramos, A.
Title (up) Chiral unitary approach to eta ' N scattering at low energies Type Journal Article
Year 2011 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 704 Issue 4 Pages 334-342
Keywords
Abstract We study the eta'N interaction within a chiral unitary approach which includes pi N, eta N and related pseudoscalar meson-baryon coupled channels. Since the SU(3) singlet does not contribute to the standard interaction and the eta' is mostly a singlet, the resulting scattering amplitude is very small and inconsistent with the experimental scattering length. The additional consideration of vector meson-baryon states into the coupled channel scheme, via normal and anomalous couplings of pseudoscalar to vector mesons, enhances substantially the eta'N amplitude. We also exploit the freedom of adding to the Lagrangian a new term, allowed by the symmetries of QCD, which couples baryons to the singlet meson of SU(3). Adjusting the unknown strength to the eta'N scattering length, we obtain predictions for the elastic eta'N -> eta'N and inelastic eta'N -> eta N, pi N, K Lambda, K Sigma cross sections at low eta' energies, and discuss their significance.
Address [Ramos, A] Univ Barcelona, Dept Estruct & Constituents Mat, E-08028 Barcelona, Spain, Email: ramos@ecm.ub.es
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 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000296175500015 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ elepoucu @ Serial 783
Permanent link to this record
 
 
Author Fonseca, R.M.; Grimus, W.
Title (up) Classification of lepton mixing matrices from finite residual symmetries Type Journal Article
Year 2014 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 09 Issue 9 Pages 033 - 54pp
Keywords Global Symmetries; Beyond Standard Model; Neutrino Physics
Abstract Assuming that neutrinos are Majorana particles, we perform a complete classification of all possible mixing matrices which are fully determined by residual symmetries in the charged-lepton and neutrino mass matrices. The classification is based on the assumption that the residual symmetries originate from a finite flavour symmetry group. The mathematical tools which allow us to accomplish this classification are theorems on sums of roots of unity. We find 17 sporadic cases plus one infinite series of mixing matrices associated with three-flavour mixing, all of which have already been discussed in the literature. Only the infinite series contains mixing matrices which are compatible with the data at the 3 sigma level.
Address [Fonseca, Renato M.] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, E-46071 Valencia, Spain, Email: renato.fonseca@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 Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000347898400002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2084
Permanent link to this record
 
 
Author Capozzi, F.; Ferreira, R.Z.; Lopez-Honorez, L.; Mena, O.
Title (up) CMB and Lyman-alpha constraints on dark matter decays to photons Type Journal Article
Year 2023 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 06 Issue 6 Pages 060 - 23pp
Keywords reionization; axions; cosmological parameters from CMBR; dark matter theory
Abstract Dark matter energy injection in the early universe modifies both the ionization history and the temperature of the intergalactic medium. In this work, we improve the CMB bounds on sub-keV dark matter and extend previous bounds from Lyman-& alpha; observations to the same mass range, resulting in new and competitive constraints on axion-like particles (ALPs) decaying into two photons. The limits depend on the underlying reionization history, here accounted self-consistently by our modified version of the publicly available DarkHistory and CLASS codes. Future measurements such as the ones from the CMB-S4 experiment may play a crucial, leading role in the search for this type of light dark matter candidates.
Address [Capozzi, Francesco] Univ Aquila, Dipartimento Sci Fis & Chim, I-67100 Laquila, Italy, Email: francesco.capozzi@univaq.it;
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 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:001025410500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5584
Permanent link to this record
 
 
Author Babeluk, M. et al; Marinas, C.
Title (up) CMOS MAPS upgrade for the Belle II Vertex Detector Type Journal Article
Year 2023 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 1048 Issue Pages 168015 - 5pp
Keywords Belle II; VXD; SVD; PXD; VTX; Upgrade; CMOS; DMAPS
Abstract The success of the Belle II experiment in Japan relies on the very high instantaneous luminosity, close to 6x1035 cm-2 s-1, expected from the SuperKEKB collider. The corresponding beam conditions at such luminosity levels generate large rates of background particles and creates stringent constraints on the vertex detector, adding to the physics requirements. Current prospects for the occupancy rates in the present vertex detector (VXD) at full luminosity fall close to the acceptable limits and bear large uncertainties. In this context, the Belle II collaboration is considering the possibility to install an upgraded VXD system around 2027 to provide a sufficient safety margin with respect to the expected background rate and possibly enhance tracking and vertexing performance. The VTX collaboration has started the design of a fully pixelated VXD, called VTX, based on fast and highly granular Depleted Monolithic Active Pixel Sensors (DMAPS) integrated on light support structures. The two main technical features of the VTX proposal are the usage of a single sensor type over all the layers of the system and the overall material budget below 2% of radiation length, compared to the current VXD which has two different sensor technologies and about 3% of radiation length. A dedicated sensor (OBELIX), taylored to the specific needs of Belle II, is under development, evolving from the existing TJ-Monopix2 sensor. The time-stamping precision below 100 ns will allow all VTX layers to take part in the track finding strategy contrary to the current situation. The first two detection layers are designed according to a self-supported all-silicon ladder concept, where 4 contiguous sensors are diced out of a wafer, thinned and interconnected with post-processed redistribution layers. The outermost detection layers follow a more conventional approach with a cold plate and carbon fibre support structure, and light flex cables interconnecting the sensors. This document will review the context, technical details and development status of the proposed Belle II VTX.
Address [Babeluk, M.; Bergauer, T.; Irmler, C.; Schwanda, C.] Austrian Acad Sci, Inst High Energy Phys, A-1050 Vienna, Austria, Email: christian.wessel@desy.de
Corporate Author Thesis
Publisher Elsevier 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:000990246200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5538
Permanent link to this record
 
 
Author Baxter, D.; Collar, J.I.; Coloma, P.; Dahl, C.E.; Esteban, I.; Ferrario, P.; Gomez-Cadenas, J.J.; Gonzalez-Garcia, M.C.; Kavner, A.R.L.; Lewis, C.M.; Monrabal, F.; Vidal, J.M.; Privitera, P.; Ramanathan, K.; Renner, J.
Title (up) Coherent elastic neutrino-nucleus scattering at the European Spallation Source Type Journal Article
Year 2020 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 02 Issue 2 Pages 123 - 38pp
Keywords Neutrino Detectors and Telescopes (experiments); Beyond Standard Model; Electroweak interaction
Abstract The European Spallation Source (ESS), presently well on its way to completion, will soon provide the most intense neutron beams for multi-disciplinary science. Fortuitously, it will also generate the largest pulsed neutrino flux suitable for the detection of Coherent Elastic Neutrino-Nucleus Scattering (CE nu NS), a process recently measured for the first time at ORNL's Spallation Neutron Source. We describe innovative detector technologies maximally able to profit from the order-of-magnitude increase in neutrino flux provided by the ESS, along with their sensitivity to a rich particle physics phenomenology accessible through high-statistics, precision CE nu NS measurements.
Address [Baxter, D.; Collar, J. I.; Kavner, A. R. L.; Lewis, C. M.; Privitera, P.; Ramanathan, K.] Univ Chicago, Enrico Fermi Inst, Kavli Inst Cosmol Phys, 5640 S Ellis Ave, Chicago, IL 60637 USA, Email: collar@uchicago.edu;
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:000515509000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4300
Permanent link to this record
 
 
Author Diamanti, R.; Ando, S.; Gariazzo, S.; Mena, O.; Weniger, C.
Title (up) Cold dark matter plus not-so-clumpy dark relics Type Journal Article
Year 2017 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 06 Issue 6 Pages 008 - 17pp
Keywords cosmological parameters from CMBR; dark matter theory; dwarfs galaxies; particle physics – cosmology connection
Abstract Various particle physics models suggest that, besides the (nearly) cold dark matter that accounts for current observations, additional but sub-dominant dark relics might exist. These could be warm, hot, or even contribute as dark radiation. We present here a comprehensive study of two-component dark matter scenarios, where the first component is assumed to be cold, and the second is a non-cold thermal relic. Considering the cases where the non-cold dark matter species could be either a fermion or a boson, we derive consistent upper limits on the non-cold dark relic energy density for a very large range of velocity dispersions, covering the entire range from dark radiation to cold dark matter. To this end, we employ the latest Planck Cosmic Microwave Background data, the recent BOSS DR11 and other Baryon Acoustic Oscillation measurements, and also constraints on the number of Milky Way satellites, the latter of which provides a measure of the suppression of the matter power spectrum at the smallest scales due to the free-streaming of the non-cold dark matter component. We present the results on the fraction f(ncdm) of non-cold dark matter with respect to the total dark matter for different ranges of the non-cold dark matter masses. We find that the 2 sigma limits for non-cold dark matter particles with masses in the range 1-10 keV are f(ncdm) <= 0.29 (0.23) for fermions (bosons), and for masses in the 10-100 keV range they are f(ncdm) <= 0.43 (0.45), respectively.
Address [Diamanti, Roberta; Ando, Shin'ichiro; Weniger, Christoph] Univ Amsterdam, Inst Phys, GRAPPA, Sci Pk 904, NL-1098 XH Amsterdam, Netherlands, Email: r.diamanti@uva.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 Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000403482400010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3174
Permanent link to this record
 
 
Author Barenboim, G.; Chun, E.J.; Lee, H.M.
Title (up) Coleman-Weinberg inflation in light of Planck Type Journal Article
Year 2014 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 730 Issue Pages 81-88
Keywords
Abstract We revisit a single field inflationary model based on Coleman-Weinberg potentials. We show that in small field Coleman-Weinberg inflation, the observed amplitude of perturbations needs an extremely small quartic coupling of the inflaton, which might be a signature of radiative origin. However, the spectral index obtained in a standard cosmological scenario turns out to be outside the 2 sigma region of the Planck data. When a non-standard cosmological framework is invoked, such as brane-world cosmology in the Randall-Sundrum model, the spectral index can be made consistent with Planck data within la, courtesy of the modification in the evolution of the Hubble parameter in such a scheme. We also show that the required inflaton quartic coupling as well as a phenomenologically viable B – L symmetry breaking together with a natural electroweak symmetry breaking can arise dynamically in a generalized B – L extension of the Standard Model where the full potential is assumed to vanish at a high scale.
Address [Barenboim, Gabriela] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain
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 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000333506400016 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1741
Permanent link to this record