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Dispersive techniques for light meson interactions and spectroscopy

Applicant Ruiz de Elvira Carrascal Jacobo
Number 174228
Funding scheme Ambizione
Research institution Institut für Theoretische Physik Universität Bern
Institution of higher education University of Berne - BE
Main discipline Particle Physics
Start/End 01.11.2017 - 31.10.2021
Approved amount 587'032.00
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All Disciplines (2)

Discipline
Particle Physics
Nuclear Physics

Keywords (2)

Dispersive Techniques for mesons; Spectroscopy of light scalars

Lay Summary (Italian)

Lead
La QCD e' considerata oggigiorno la teoria che meglio descrive l'interazione forte.D'altra parte, lo spettro degli adroni più leggeri è tuttora oggetto discussione, dato che a basse energie la QCD diviene non-perturbativa, impedendo un calcolo teorico dello spettro.Inoltre, lo scattering pione-pione e pione-kaone rivestono un ruolo essenziale in quasi tutti i processi forti studiati dalle collaborazioni sperimentali in tutto il mondo;ciò è dovuto al fatto che pioni e kaoni, i mesoni più leggeri, interagiscono negli stati finali di tali processi, e ciò è vero soprattutto nel caso dei decadimenti dei mesoni Phi, D e B.L'assenza di ampiezze di scattering pione-pione e pione-kaone precise e model-independent è pertanto un ostacolo nel percorso verso conclusioni precise ed affidabili per molti dei processi che, altrimenti, potrebbero essere studiati.
Lay summary
Tuttavia, negli ultimi anni, l'utilizzo di tecniche di dispersione model-independent ha posto fine alla lunga controversia riguardante lo scattering pione-pione ad al suo spettro di massa a basse energie.
Le relazioni di dispersione sono una conseguenza della causalità, la quale matematicamente si traduce in condizioni di analiticità per le ampiezze di scattering.
Nel caso dello scattering e della spettroscopia mesone-mesone, le ampiezze di scattering sono espresse in termini di ampiezze d'onda parziale con momento angolare definito.
S. M. Roy ha dimostrato che, per tali onde parziali, i vincoli di analiticità  per lo scattering elastico pione-pione si traducono in un sistema di equazioni integrali.
Nel caso di scattering elastico pione-kaone esistono delle relazioni simili, dette equazioni di Roy-Steiner.
Le equazioni di Roy e di Roy-Steiner forniscono dei constraints molto forti nel caso di scattering pione-pione e pone-kaone, permettendo di determinare lo spettro adronico in modo univoco.

Sfortunatamente, ad oggi, le tecniche model-independent esistenti sono matematicamente limitate ad energie al di sotto di 1 GeV, rendendo perciò impossibile lo studio di particelle ed ampiezze
ad energie al di sopra di 1 GeV.

Lo scopo di tale proposta è quello di derivare un set di relazioni di dispersione per le ampiezze di onda parziale valide al di sopra di 1 GeV.
L'elaborazione di tale proposta è stata motivata non solo dalla situazione nel campo, ma anche dalla richiesta di altri ricercatori e gruppi sperimentali.

Tale estensione avrà un impatto significativo sugli esperimenti in corso per processi che includono pioni e kaoni, e sulla revisione delle incertezze nelle grandezze inerenti svariate
particelle aventi massa superiore al GeV.
 
Direct link to Lay Summary Last update: 11.09.2017

Responsible applicant and co-applicants

Employees

Publications

Publication
Chiral extrapolation of hadronic vacuum polarization
Colangelo Gilberto, Hoferichter Martin, Kubis Bastian, Niehus Malwin, Ruiz de Elvira Jacobo (2022), Chiral extrapolation of hadronic vacuum polarization, in Physics Letters B, 825, 136852-136852.
The role of strangeness in chiral and $$U(1)_A$$ restoration
Gómez Nicola A., Ruiz de Elvira J., Vioque-Rodríguez A., Álvarez-Herrero D. (2021), The role of strangeness in chiral and $$U(1)_A$$ restoration, in The European Physical Journal C, 81(7), 637-637.
Precision dispersive approaches versus unitarized chiral perturbation theory for the lightest scalar resonances $$\sigma /f_0(500) $$ and $$\kappa /K_0^*(700) $$
Peláez José R., Rodas Arkaitz, Ruiz de Elvira Jacobo (2021), Precision dispersive approaches versus unitarized chiral perturbation theory for the lightest scalar resonances $$\sigma /f_0(500) $$ and $$\kappa /K_0^*(700) $$, in The European Physical Journal Special Topics, 230(6), 1539-1574.
Two-Loop Analysis of the Pion Mass Dependence of the ρ Meson
Niehus Malwin, Hoferichter Martin, Kubis Bastian, Ruiz de Elvira Jacobo (2021), Two-Loop Analysis of the Pion Mass Dependence of the ρ Meson, in Physical Review Letters, 126(10), 102002-102002.
Light- and strange-quark mass dependence of the ρ(770) meson revisited
Molina R., de Elvira J. Ruiz (2020), Light- and strange-quark mass dependence of the ρ(770) meson revisited, in Journal of High Energy Physics, 2020(11), 17-17.
The XVIII International Conference on Strangeness in Quark Matter (SQM 2019)
Gómez Nicola Angel, Ruiz de Elvira Jacobo, Vioque-Rodríguez Andrea (2020), The XVIII International Conference on Strangeness in Quark Matter (SQM 2019), Springer International Publishing, Cham.
Coarse graining hadronic scattering
Ruiz Arriola Enrique, Jacobo Ruiz de Elvira (2020), Coarse graining hadronic scattering, in The 9th International workshop on Chiral Dynamics, Durham, NC, USASISSA, Italy.
Dispersive techniques for low-energy QCD: Pion-pion and pion-kaon scattering
Ruiz de Elvira Jacobo (2020), Dispersive techniques for low-energy QCD: Pion-pion and pion-kaon scattering, in The 9th International workshop on Chiral Dynamics, Durham, NC, USASISSA, Italy.
Roy–Steiner equations for pion–nucleon scattering and the pion–nucleon $σ$-term
Hoferichter Martin, Ruiz de Elvira Jacobo, Kubis Bastian, Meißner Ulf-G. (2020), Roy–Steiner equations for pion–nucleon scattering and the pion–nucleon $σ$-term, in The 9th International workshop on Chiral Dynamics, Durham, NC, USASISSA, Italy.
Light Strange Resonances from Analyticity and Dispersion Relations
Peláez J.R., Rodas A., Ruiz de Elvira J. (2020), Light Strange Resonances from Analyticity and Dispersion Relations, in Acta Physica Polonica B Proceedings Supplement, 13(1), 39-39.
Global parameterization of $$\pi \pi $$ scattering up to 2 $${\mathrm {\,GeV}}$$
Pelaez J. R., Rodas A., Ruiz de Elvira J. (2019), Global parameterization of $$\pi \pi $$ scattering up to 2 $${\mathrm {\,GeV}}$$, in The European Physical Journal C, 79(12), 1008-1008.
The QCD topological charge and its thermal dependence: the role of the η′
Nicola A. Gómez, de Elvira J. Ruiz, Vioque-Rodríguez A. (2019), The QCD topological charge and its thermal dependence: the role of the η′, in Journal of High Energy Physics, 2019(11), 86-86.
Chiral and U(1)_A restoration: Ward Identities and effective theories
Gómez Nicola Ángel, Ruiz de Elvira Jacobo, Vioque-Rodríguez Andrea, Ferreres-Solé Silvia (2019), Chiral and U(1)_A restoration: Ward Identities and effective theories, in XIII Quark Confinement and the Hadron Spectrum, Maynooth University , IrelandProceedings of Science, Trieste, Italy.
Dispersive analysis of the κ / K0* (700) meson and other light strange resonances
Peláez José R., Rodas Arkaitz, Ruiz de Elvira Jacobo (2019), Dispersive analysis of the κ / K0* (700) meson and other light strange resonances, in EPJ Web of Conferences, 212, 03003-03003.
Nucleon Matrix Elements of the Antisymmetric Quark Tensor
Hoferichter Martin, Kubis Bastian, Ruiz de Elvira Jacobo, Stoffer Peter (2019), Nucleon Matrix Elements of the Antisymmetric Quark Tensor, in Physical Review Letters, 122(12), 122001-122001.
Coarse graining ππ scattering
Ruiz de Elvira Jacobo, Ruiz Arriola Enrique (2018), Coarse graining ππ scattering, in The European Physical Journal C, 78(11), 878-878.
Chiral and U(1)_A restoration for the scalar and pseudoscalar meson nonets
Gómez Nicola A., Ruiz de Elvira J. (2018), Chiral and U(1)_A restoration for the scalar and pseudoscalar meson nonets, in Physical Review D, 98(1), 014020-014020.
Patterns and partners for chiral symmetry restoration
Gómez Nicola A., Ruiz de Elvira J. (2018), Patterns and partners for chiral symmetry restoration, in Physical Review D, 97(7), 074016-074016.
Calculation of strange resonances from $K\pi$ scattering
Rodas Arkaitz, Peláez José R., Ruiz de Elvira Jacobo (2018), Calculation of strange resonances from $K\pi$ scattering, in XVII International Conference on Hadron Spectroscopy and Structure, University of Salamanca, Salamanca, SpainProceedings of Science, Trieste, Italy.
Dispersive analysis of pion-nucleon scattering and the pion-nucleon sigma term
Ruiz de Elvira Jacobo, Hoferichter Martin, Kubis Bastian, Mei{\ss}ner Ulf-G.\ (2018), Dispersive analysis of pion-nucleon scattering and the pion-nucleon sigma term, in XVII International Conference on Hadron Spectroscopy and Structure, University of Salamanca, Salamanca, SpainProceedings of Science, Trieste, Italy.
Recent advances on chiral partners and patterns and the thermal f0(500) in chiral restoration
Gómez Nicola Ángel, Ruiz de Elvira Jacobo, Ferreres-Solé Silvia, Vioque-Rodríguez Andrea (2018), Recent advances on chiral partners and patterns and the thermal f0(500) in chiral restoration, in XVII International Conference on Hadron Spectroscopy and Structure, University of Salamanca, Salamanca, SpainProceedings of Science, Trieste, Italy.
Extracting the σ -term from low-energy pion-nucleon scattering
Elvira Jacobo Ruiz de, Hoferichter Martin, Kubis Bastian, Meißner Ulf-G (2018), Extracting the σ -term from low-energy pion-nucleon scattering, in Journal of Physics G: Nuclear and Particle Physics, 45(2), 024001-024001.

Collaboration

Group / person Country
Types of collaboration
Effective Field Theory group led by Gilberto Colangelo, ITP, Bern University Switzerland (Europe)
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Fourth workshop on perceiving the emergence of hadron mass through Amber@CERN Talk given at a conference ChPT relation to the Emergence of Hadron Masses 04.12.2020 Geneva, Switzerland Ruiz de Elvira Carrascal Jacobo;
Accessing and Understanding the QCD Spectra Talk given at a conference Dispersion relations and the QCD Spectra 02.09.2020 Seattle, United States of America Ruiz de Elvira Carrascal Jacobo;
Seminar at the theoretical physics department at Siegen University Individual talk Dispersive determination of nucleon matrix elements 11.05.2020 Siegen, Germany Ruiz de Elvira Carrascal Jacobo;
2nd Workshop on Hadronic Contributions to New Physics Searches Talk given at a conference Dispersive theory for baryon structure 28.09.2019 Puerto de la Cruz, Tenerife, Spain Ruiz de Elvira Carrascal Jacobo;
GSI/FAIR Symposium on QCD and Hadron Physics Individual talk Strong interactions and the precision frontier of Hadron Physics 23.08.2019 Darmstadt, Germany Ruiz de Elvira Carrascal Jacobo;
18th International Conference on Hadron Spectroscopy and Structure (HADRON2019) Poster Convener of the Hadron decays, production and interactions session 16.08.2019 Guilin, China Ruiz de Elvira Carrascal Jacobo;
Physics Colloquium, Physics Department, College of William and Mary Individual talk Strong interactions and the precision frontier of Hadron Physics 22.02.2019 Williamsburg, Virginia, United States of America Ruiz de Elvira Carrascal Jacobo;
INTERFACE OF EFFECTIVE FIELD THEORIES AND LATTICE GAUGE THEORY Talk given at a conference Chiral transition in EFT approach 30.10.2018 Munich, Germany Ruiz de Elvira Carrascal Jacobo;
The Ninth International Workshop on Chiral Dynamics (CD18) Talk given at a conference Dispersive techniques for low-energy QCD: Pion-pion and pion-kaon scattering 17.09.2018 Durham, North Carolina, United States of America Ruiz de Elvira Carrascal Jacobo;
TRR110 Workshop - Amplitudes for Three-Body Final States Talk given at a conference Dispersive analysis for πK 11.07.2018 Munich, Germany Ruiz de Elvira Carrascal Jacobo;
New Ideas in Constraining Nuclear Forces Talk given at a conference Determination of the pion-nucleon low-energy constants 04.06.2018 Trento, Italy Ruiz de Elvira Carrascal Jacobo;
Pion-Kaon Interactions Workshop Talk given at a conference Dispersive determination of the pion-kaon scattering lengths 14.02.2018 Newport News, United States of America Ruiz de Elvira Carrascal Jacobo;
Multi-Hadron Systems from Lattice QCD (INT 18-70W) Talk given at a conference Dispersive techniques for lattice analysis 05.02.2018 Seattle, United States of America Ruiz de Elvira Carrascal Jacobo;
Theoretical physics department, Complutense university of Madrid Individual talk Dispersive analysis of pion nucleon scattering and the sigma term 20.12.2017 Madrid, Spain Ruiz de Elvira Carrascal Jacobo;
Particle physics department, University of Vienna Individual talk Dispersive analysis of pion nucleon scattering and the sigma term 28.11.2017 Vienna, Austria Ruiz de Elvira Carrascal Jacobo;
2nd Workshop on Future Directions in Spectroscopy Analysis (FDSA2017) Talk given at a conference Roy-Steiner-equation analysis of pion-nucleon scattering 07.11.2017 Mexico City, Mexico Ruiz de Elvira Carrascal Jacobo;


Abstract

Light scalar mesons are a longstanding puzzle in our understanding of strong interactions. They are very relevant both for Nuclear and Particle Physics. For the former because they are largely responsible for nucleon-nucleon attraction, and for the latter due to their role in spontaneous Chiral Symmetry Breaking and the identification of glueballs - two fundamental features of QCD. Moreover, there is an ongoing worldwide experimental program on strong interactions (CERN, China, Germany, Japan & USA), looking for New Physics, where many results depend on final state interactions of pions and kaons and scalar meson production. Nevertheless, despite this relevance, their existence, properties and nature have been controversial for many decades, mostly due to the use of model dependent approaches and conflicting data sets.However, recently, and according to the Particle Data Group (PDG), there has been a radical and very substantial revision of pion-pion interactions and of the two lightest resonances below 1.1 GeV, the f0(500) or sigma meson and the f0(980), driven by model independent and precise dispersive techniques. In particular, my previous work has played a leading role in this progress, providing a set of model independent parameterizations describing pion-pion scattering below 1.1 GeV, which are being used by many theoretical and experimental groups.Encouraged by the requests of many colleagues, including experimentalists in active collaborations or PDG members, I plan to extend this remarkable success of dispersion theory to obtain a precise description of pion-pion scattering beyond 1 GeV up to the next resonant region, as well as to pion-kaon scattering, which should lead to another substantial revision of the lightest strange scalar resonance. This program will be extremely useful for a broad spectrum of application, ranging from the description of nucleon-nucleon scattering, the proton radius puzzle or the study of heavy-meson decay properties where pion appear in the final state interactions. For this purpose I will have to develop new methods to extend the existing dispersive formalism beyond 1 GeV and apply them, through intensive numerical calculations, to the analysis of data. Then I will provide model independent and ready to use parameterizations to the community, and precise determinations of resonance parameters.
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