The HiggsTools handbook: a beginners guide to decoding the Higgs sector
| Autor: | Juan Cruz-Martinez, Shruti Patel, Davide Napoletano, Giampiero Passarino, Nigel Glover, SP Jones, D. Melini, Giulia Gonella, Raquel Gomez-Ambrosio, Frank Krauss, Hjalte Frellesvig, Zahari Kassabov, T. Wolf, Y. Haddad, Matias Rodriguez-Vazquez, Agnieszka Ilnicka, Michele Boggia, T. Megy |
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| Přispěvatelé: | Laboratoire de Physique Théorique d'Orsay [Orsay] (LPT), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Théorique d'Orsay [Orsay] ( LPT ), Université Paris-Sud - Paris 11 ( UP11 ) -Centre National de la Recherche Scientifique ( CNRS ), Boggia, M, Cruz-Martinez, J, 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 |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Nuclear and High Energy Physics
Particle physics Top quark coupling [Higgs particle] Higgs particle: decay Higgs boson Physics beyond the Standard Model momentum spectrum [transverse momentum] 01 natural sciences Standard Model Higgs sector transverse momentum: momentum spectrum effective field theory effective field theories Higgs momentum distributions LHC physics new physics searches search for [new physics] [ PHYS.HEXP ] Physics [physics]/High Energy Physics - Experiment [hep-ex] 0103 physical sciences Effective field theory [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex] ddc:530 effective field theorie 010306 general physics Monte Carlo Physics LHC physic Large Hadron Collider Higgs particle: coupling 010308 nuclear & particles physics new physics: search for Electroweak interaction High Energy Physics::Phenomenology new physics searche decay [Higgs particle] two-photon [final state] Higgs momentum distribution production [Higgs particle] CERN LHC Coll Higgs particle: production [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph] [ PHYS.HPHE ] Physics [physics]/High Energy Physics - Phenomenology [hep-ph] High Energy Physics::Experiment final state: two-photon |
| Zdroj: | J.Phys.G J.Phys.G, 2018, 45 (6), pp.065004. ⟨10.1088/1361-6471/aab812⟩ Journal of physics / G 45(6), 065004 (2018). doi:10.1088/1361-6471/aab812 J.Phys.G, 2018, 45 (6), pp.065004. 〈10.1088/1361-6471/aab812〉 |
| DOI: | 10.1088/1361-6471/aab812⟩ |
| Popis: | 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 κ-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 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. |
| Databáze: | OpenAIRE |
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