Records |
Author |
Boggia, M.; Cruz-Martinez, J.M.; Frellesvig, H.; Glover, N.; Gomez-Ambrosio, R.; Gonella, G.; Haddad, Y.; Ilnicka, A.; Jones, S.; Kassabov, Z.; Krauss, F.; Megy, T.; Melini, D.; Napoletano, D.; Passarino, G.; Patel, S.; Rodriguez-Vazquez, M.; Wolf, T. |
Title |
The HiggsTools handbook: a beginners guide to decoding the Higgs sector |
Type |
Journal Article |
Year |
2018 |
Publication |
Journal of Physics G |
Abbreviated Journal |
J. Phys. G |
Volume |
45 |
Issue |
6 |
Pages |
065004 - 152pp |
Keywords |
LHC physics; Higgs boson; new physics searches; effective field theories; Higgs momentum distributions |
Abstract |
This report summarises some of the activities of the HiggsTools initial training network working group in the period 2015-2017. The main goal of this working group was to produce a document discussing various aspects of state-of-the-art Higgs physics at the large hadron collider (LHC) in a pedagogic manner The first part of the report is devoted to a description of phenomenological searches for new physics (NP) at the LHC. All of the available studies of the couplings of the new resonance discovered in 2012 by the ATLAS and CMS experiments (Aad et al (ATLAS Collaboration) 2012 Phys. Lett. B 716 1-29; Chatrchyan et al (CMS Collaboration) 2012 Phys. Lett. B 716 30-61) conclude that it is compatible with the Higgs boson of the standard model (SM) within present precision. So far the LHC experiments have given no direct evidence for any physical phenomena that cannot be described by the SM. As the experimental measurements become more and more precise, there is a pressing need for a consistent framework in which deviations from the SM predictions can be computed precisely. Such a framework should be applicable to measurements in all sectors of particle physics, not only LHC Higgs measurements but also electroweak precision data, etc. We critically review the use of the k-framework, fiducial and simplified template cross sections, effective field theories, pseudoobservables and phenomenological Lagrangians. Some of the concepts presented here are well known and were used already at the time of the large electron-positron collider (LEP) experiment. However, after years of theoretical and experimental development, these techniques have been refined, and we describe new tools that have been introduced in order to improve the comparison between theory and experimental data. In the second part of the report, we propose Phi(eta)* as a new and complementary observable for studying Higgs boson production at large transverse momentum in the case where the Higgs boson decays to two photons. The Phi(eta)* variable depends on measurements of the angular directions and rapidities of the two Higgs decay products rather than the energies, and exploits the information provided by the calorimeter in the detector. We show that, even without tracking information, the experimental resolution for Phi(eta)* is better than that of the transverse momentum of the photon pair, particularly at low transverse momentum. We make a detailed study of the phenomenology of the Phi(eta)* variable, contrasting the behaviour with the Higgs transverse momentum distribution using a variety of theoretical tools including event generators and fixed order perturbative computations. We consider the theoretical uncertainties associated with both p TH and Phi(eta)* distributions. Unlike the transverse momentum distribution, the Phi(eta)* distribution is well predicted using the Higgs effective field theory in which the top quark is integrated out-even at large values of Phi(eta)*-thereby making this a better observable for extracting the parameters of the Higgs interaction. In contrast, the potential of the Phi(eta)* distribution as a probe of NP is rather limited, since although the overall rate is affected by the presence of additional heavy fields, the shape of the Phi(eta)* distribution is relatively insensitive to heavy particle thresholds. |
Address |
[Boggia, M.; Gonella, G.; Jones, S.; Megy, T.] Albert Ludwigs Univ Freiburg, Phys Inst, D-79104 Freiburg, Germany, Email: raquel.gomez-ambrosio@durham.ac.uk |
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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 |
0954-3899 |
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:000434094000001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3604 |
Permanent link to this record |
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Author |
ATLAS Collaboration (Aaboud, M. et al); Alvarez Piqueras, D.; Barranco Navarro, L.; Cabrera Urban, S.; Castillo Gimenez, V.; Cerda Alberich, L.; Costa, M.J.; Escobar, C.; Estrada Pastor, O.; Fernandez Martinez, P.; Ferrer, A.; Fiorini, L.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gonzalez de la Hoz, S.; Higon-Rodriguez, E.; Jimenez Pena, J.; Lacasta, C.; Madaffari, D.; Mamuzic, J.; Marti-Garcia, S.; Melini, D.; Mitsou, V.A.; Pedraza Lopez, S.; Rodriguez Bosca, S.; Rodriguez Rodriguez, D.; Romero Adam, E.; Salt, J.; Soldevila, U.; Sanchez, J.; Valero, A.; Valls Ferrer, J.A.; Vos, M. |
Title |
Measurement of the Soft-Drop Jet Mass in pp Collisions at root s=13 TeV with the ATLAS Detector |
Type |
Journal Article |
Year |
2018 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
121 |
Issue |
9 |
Pages |
092001 - 21pp |
Keywords |
|
Abstract |
Jet substructure observables have significantly extended the search program for physics beyond the standard model at the Large Hadron Collider. The state-of-the-art tools have been motivated by theoretical calculations, but there has never been a direct comparison between data and calculations of jet substructure observables that are accurate beyond leading-logarithm approximation. Such observables are significant not only for probing the collinear regime of QCD that is largely unexplored at a hadron collider, but also for improving the understanding of jet substructure properties that are used in many studies at the Large Hadron Collider. This Letter documents a measurement of the first jet substructure quantity at a hadron collider to be calculated at next-to-next-to-leading-logarithm accuracy. The normalized, differential cross section is measured as a function of log(10)rho(2), where rho is the ratio of the soft-drop mass to the ungroomed jet transverse momentum. This quantity is measured in dijet events from 32.9 fb(-1) of root s = 13 TeV proton-proton collisions recorded by the ATLAS detector. The data are unfolded to correct for detector effects and compared to precise QCD calculations and leading-logarithm particle-level Monte Carlo simulations. |
Address |
[Duvnjak, D.; Jackson, P.; Petridis, A.; White, M. J.] Univ Adelaide, Dept Phys, Adelaide, SA, Australia |
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 |
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Conference |
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Notes |
WOS:000442889500003 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3712 |
Permanent link to this record |
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Author |
Gonzalez, M.; Hirsch, M.; Kovalenko, S.G. |
Title |
Neutrinoless double beta decay and QCD running at low energy scales |
Type |
Journal Article |
Year |
2018 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
97 |
Issue |
11 |
Pages |
115005 - 6pp |
Keywords |
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Abstract |
There is a common belief that the main uncertainties in the theoretical analysis of neutrinoless double beta (0 nu beta beta) decay originate from the nuclear matrix elements. Here, we uncover another previously overlooked source of potentially large uncertainties stemming from nonperturbative QCD effects. Recently perturbative QCD corrections have been calculated for all dimension 6 and 9 effective operators describing 0 nu beta beta-decay and their importance for a reliable treatment of 0 nu beta beta-decay has been demonstrated. However, these perturbative results are valid at energy scales above similar to 1 GeV, while the typical 0 nu beta beta scale is about similar to 100 MeV. In view of this fact we examine the possibility of extrapolating the perturbative results towards sub-GeV nonperturbative scales on the basis of the QCD coupling constant “freezing” behavior using background perturbation theory. Our analysis suggests that such an infrared extrapolation does modify the perturbative results for both short-range and long-range mechanisms of 0 nu beta beta-decay in general only moderately. We also discuss that the tensor circle times tensor effective operator cannot appear alone in the low energy limit of any renormalizable high-scale model and then demonstrate that all five linearly independent combinations of the scalar and tensor operators, which can appear in renormalizable models, are infrared stable. |
Address |
[Gonzalez, M.; Kovalenko, S. G.] Univ Tecn Federico Santa Maria, Ctr Cient Tecnol Valparaiso, Casilla 110-V, Valparaiso 2390123, Chile, Email: marcela.gonzalezp@usm.cl; |
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 |
2470-0010 |
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:000434211200008 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3603 |
Permanent link to this record |
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Author |
ANTARES Collaboration (Bhandari, S. et al); Barrios-Marti, J.; Coleiro, A.; Hernandez-Rey, J.J.; Illuminati, G.; Tönnis, C.; Zornoza, J.D.; Zuñiga, J. |
Title |
The SUrvey for Pulsars and Extragalactic Radio Bursts – II. New FRB discoveries and their follow-up |
Type |
Journal Article |
Year |
2018 |
Publication |
Monthly Notices of the Royal Astronomical Society |
Abbreviated Journal |
Mon. Not. Roy. Astron. Soc. |
Volume |
475 |
Issue |
2 |
Pages |
1427-1446 |
Keywords |
radiation mechanisms: general; methods: data analysis; methods: observational; surveys; intergalactic medium; radio continuum: general |
Abstract |
We report the discovery of four Fast Radio Bursts (FRBs) in the ongoing SUrvey for Pulsars and Extragalactic Radio Bursts at the Parkes Radio Telescope: FRBs 150610, 151206, 151230 and 160102. Our real-time discoveries have enabled us to conduct extensive, rapid multimessenger follow-up at 12 major facilities sensitive to radio, optical, X-ray, gamma-ray photons and neutrinos on time-scales ranging from an hour to a few months post-burst. No counterparts to the FRBs were found and we provide upper limits on afterglow luminosities. None of the FRBs were seen to repeat. Formal fits to all FRBs show hints of scattering while their intrinsic widths are unresolved in time. FRB 151206 is at low Galactic latitude, FRB 151230 shows a sharp spectral cut-off, and FRB 160102 has the highest dispersion measure (DM = 2596.1 +/- 0.3 pc cm(-3)) detected to date. Three of the FRBs have high dispersion measures (DM > 1500 pc cm(-3)), favouring a scenario where the DMis dominated by contributions from the intergalactic medium. The slope of the Parkes FRB source counts distribution with fluences > 2 Jy ms is alpha = – 2.2(-1.2)(+0.6) and still consistent with a Euclidean distribution (alpha = -3/2). We also find that the all-sky rate is 1.7(-0.9)(+1.5) x 10(3)FRBs/(4 pi sr)/day above similar to 2 Jy ms and there is currently no strong evidence for a latitude- dependent FRB sky rate. |
Address |
[Bhandari, S.; Keane, E. F.; Barr, E. D.; Jameson, A.; Petroff, E.; Bailes, M.; Flynn, C.; Jankowski, F.; Krishnan, V. Venkatraman; Morello, V.; van Straten, W.; Andreoni, I.; Cooke, J.; Pritchard, T.] Swinburne Univ Technol, Ctr Astrophys & Supercomp, Mail H30,POB 218, Hawthorn, Vic 3122, Australia, Email: shivanibhandari58@gmail.com |
Corporate Author |
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Thesis |
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Publisher |
Oxford Univ Press |
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 |
0035-8711 |
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:000427345900001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3518 |
Permanent link to this record |
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Author |
ANTARES Collaboration (Albert, A. et al); Barrios-Marti, J.; Coleiro, A.; Hernandez-Rey, J.J.; Illuminati, G.; Lotze, M.; Tönnis, C.; Zornoza, J.D.; Zuñiga, J. |
Title |
All-flavor Search for a Diffuse Flux of Cosmic Neutrinos with Nine Years of ANTARES Data |
Type |
Journal Article |
Year |
2018 |
Publication |
Astrophysical Journal Letters |
Abbreviated Journal |
Astrophys. J. Lett. |
Volume |
853 |
Issue |
1 |
Pages |
L7 - 5pp |
Keywords |
astroparticle physics; neutrinos |
Abstract |
The ANTARES detector is at present the most sensitive neutrino telescope in the northern hemisphere. The highly significant cosmic neutrino excess observed by the Antarctic IceCube detector can be studied with ANTARES, exploiting its complementing field of view, exposure, and lower energy threshold. Searches for an all-flavor diffuse neutrino signal, covering nine years of ANTARES data taking, are presented in this Letter. Upward-going events are used to reduce the atmospheric muon background. This work includes for the first time in ANTARES both track-like (mainly nu mu) and shower-like (mainly nu(e)) events in this kind of analysis. Track-like events allow for an increase of the effective volume of the detector thanks to the long path traveled by muons in rock and/ or sea water. Shower-like events are well reconstructed only when the neutrino interaction vertex is close to, or inside, the instrumented volume. A mild excess of high-energy events over the expected background is observed in nine years of ANTARES data in both samples. The best fit for a single power-law cosmic neutrino spectrum, in terms of perflavor flux at 100 TeV, is Phi(1f)(0) (100 TeV) = (1.7 +/- 1.0) x 10(-18) GeV-1 cm(-2) s(-1) sr(-1) with spectral index Gamma = 2.4(-0.4)(+0.5) .The null cosmic flux assumption is rejected with a significance of 1.6 sigma . |
Address |
[Albert, A.; Drouhin, D.; Racca, C.] Inst Univ Technol Colmar, Univ Haute Alsace, GRPHE, 34 Rue Grillenbreit BP, F-505686800 Colmar, France, Email: lfusco@bo.infn.it; |
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 |
2041-8205 |
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:000423182700004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3456 |
Permanent link to this record |