Project

Back to overview

What's behind Flavour Anomalies?

English title What's behind Flavour Anomalies?
Applicant Serra Nicola
Number 173104
Funding scheme SNSF Professorships
Research institution Physik-Institut Universität Zürich
Institution of higher education University of Zurich - ZH
Main discipline Particle Physics
Start/End 01.07.2017 - 30.06.2019
Approved amount 637'428.00
Show all

Keywords (7)

Flavour anomalies; New Physics; Charmless B-hadron decays; Flavour Physics; Rare B-meson decays; Lepton Universality; LHCb

Lay Summary (Italian)

Lead
Esistono evidenze macroscopiche (cosmologiche ed astrofisiche) che la nostra comprensione delle interazioni tra particelle elementari, descritta dal così detto Modello Standard, non sia completa. Tra queste si annovera l'esistenza della materia oscura e la grande asimmetria tra materia ed antimateria nell'Universo osservabile. Recentemente, alcune anomalie in decadimenti di particelle sono state misurate dall'esperimento LHCb. Che siano queste le prime evidenze microscopiche dell'esistenza di nuove particelle elementari?
Lay summary

La scoperta di nuove particelle elementari è uno dei principali obbiettivi della ricerca in fisica fondamentale. Si pensa infatti che questa ci guiderebbe alla comprensione dell'Universo primordiale e di quello attuale. Ci aiuterebbe nel comprendere in cosa consista la materia oscura e come la materia ordinaria abbia prevalso sull'antimateria nell'evoluzione dell'Universo. 

L'osservazione di anomalie in alcuni decadimenti di particelle contenenti il quark beauty, da parte dell'esperimento LHCb potrebbero essere la prima evidenza dell'esistenza di queste nuove particelle. 
Questa ricerca si propone di dare una risposta definitiva al fatto che le anomalie siano dovute a errori strumentali o incertezze statistiche o se nuove particelle siano effettivamente responsabili degli effetti osservati. Per ottenere questo risultato verranno studiati molti decadimenti di particelle contenenti il quark beauty.  Un'analisi globale delle proprietà di questi decadimenti sarà in grado di dare una risposta finale sulla natura di queste anomalie. 
Direct link to Lay Summary Last update: 04.05.2018

Responsible applicant and co-applicants

Employees

Publications

Publication
Study of the B0 → ρ(770)°K*(892)0 decay with an amplitude analysis of B0 → (π+π−)(K+π−) decays
Aaij R., Abellán Beteta C., Adeva B., Adinolfi M., Aidala C. A., Ajaltouni Z., Akar S., Albicocco P., Albrecht J., Alessio F., Alexander M., Alfonso Albero A., Alkhazov G., Alvarez Cartelle P., Alves A. A., Amato S., Amerio S., Amhis Y., An L., Anderlini L., Andreassi G., Andreotti M., Andrews J. E., Archilli F., et al. (2019), Study of the B0 → ρ(770)°K*(892)0 decay with an amplitude analysis of B0 → (π+π−)(K+π−) decays, in Journal of High Energy Physics, 2019(5), 26-26.
Towards establishing lepton flavor universality violation in B¯→K¯*ℓ+ℓ− decays
Mauri Andrea, Serra Nicola, Silva Coutinho Rafael (2019), Towards establishing lepton flavor universality violation in B¯→K¯*ℓ+ℓ− decays, in Physical Review D, 99(1), 013007-013007.
Testing lepton flavour universality in semileptonic Λb → Λc* decays
Böer Philipp, Bordone Marzia, Graverini Elena, Owen Patrick, Rotondo Marcello, van Dyk Danny (2018), Testing lepton flavour universality in semileptonic Λb → Λc* decays, in Journal of High Energy Physics, 2018(6), 155-155.
Amplitude Analysis of the Decay B¯0→KS0π+π− and First Observation of the CP Asymmetry in B¯0→K*(892)−π+
Aaij R., Adeva B., Adinolfi M., Ajaltouni Z., Akar S., Albrecht J., Alessio F., Alexander M., Alfonso Albero A., Ali S., Alkhazov G., Alvarez Cartelle P., Alves A. A., Amato S., Amerio S., Amhis Y., An L., Anderlini L., Andreassi G., Andreotti M., Andrews J. E., Appleby R. B., Archilli F., d’Argent P., et al. (2018), Amplitude Analysis of the Decay B¯0→KS0π+π− and First Observation of the CP Asymmetry in B¯0→K*(892)−π+, in Physical Review Letters, 120(26), 261801-261801.
An empirical model to determine the hadronic resonance contributions to $$\overline{B}{} ^0 \!\rightarrow \overline{K}{} ^{*0} \mu ^+ \mu ^- $$B¯0→K¯∗0μ+μ- transitions
Blake T., Egede U., Owen P., Petridis K. A., Pomery G. (2018), An empirical model to determine the hadronic resonance contributions to $$\overline{B}{} ^0 \!\rightarrow \overline{K}{} ^{*0} \mu ^+ \mu ^- $$B¯0→K¯∗0μ+μ- transitions, in The European Physical Journal C, 78(6), 453-453.
A global fit of the MSSM with GAMBIT
Athron Peter, Balázs Csaba, Bringmann Torsten, Buckley Andy, Chrząszcz Marcin, Conrad Jan, Cornell Jonathan M., Dal Lars A., Edsjö Joakim, Farmer Ben, Jackson Paul, Krislock Abram, Kvellestad Anders, Mahmoudi Farvah, Martinez Gregory D., Putze Antje, Raklev Are, Rogan Christopher, Saavedra Aldo, Savage Christopher, Scott Pat, Serra Nicola, Weniger Christoph, White Martin (2017), A global fit of the MSSM with GAMBIT, in The European Physical Journal C, 77(12), 879-879.
Global fits of GUT-scale SUSY models with GAMBIT
Athron Peter, Balázs Csaba, Bringmann Torsten, Buckley Andy, Chrząszcz Marcin, Conrad Jan, Cornell Jonathan M., Dal Lars A., Edsjö Joakim, Farmer Ben, Jackson Paul, Krislock Abram, Kvellestad Anders, Mahmoudi Farvah, Martinez Gregory D., Putze Antje, Raklev Are, Rogan Christopher, de Austri Roberto Ruiz, Saavedra Aldo, Savage Christopher, Scott Pat, Serra Nicola, Weniger Christoph, et al. (2017), Global fits of GUT-scale SUSY models with GAMBIT, in The European Physical Journal C, 77(12), 824-824.
FlavBit: a GAMBIT module for computing flavour observables and likelihoods
Bernlochner Florian U., Chrząszcz Marcin, Dal Lars A., Farmer Ben, Jackson Paul, Kvellestad Anders, Mahmoudi Farvah, Putze Antje, Rogan Christopher, Scott Pat, Serra Nicola, Weniger Christoph, White Martin (2017), FlavBit: a GAMBIT module for computing flavour observables and likelihoods, in The European Physical Journal C, 77(11), 786-786.
GAMBIT: the global and modular beyond-the-standard-model inference tool
Athron Peter, Balazs Csaba, Bringmann Torsten, Buckley Andy, Chrząszcz Marcin, Conrad Jan, Cornell Jonathan M., Dal Lars A., Dickinson Hugh, Edsjö Joakim, Farmer Ben, Gonzalo Tomás E., Jackson Paul, Krislock Abram, Kvellestad Anders, Lundberg Johan, McKay James, Mahmoudi Farvah, Martinez Gregory D., Putze Antje, Raklev Are, Ripken Joachim, Rogan Christopher, Saavedra Aldo, et al. (2017), GAMBIT: the global and modular beyond-the-standard-model inference tool, in The European Physical Journal C, 77(11), 784-784.
Updated branching fraction measurements of B(s)0 → KS0h+h′ − decays
Aaij R., Adeva B., Adinolfi M., Ajaltouni Z., Akar S., Albrecht J., Alessio F., Alexander M., Ali S., Alkhazov G., Alvarez Cartelle P., Alves A. A., Amato S., Amerio S., Amhis Y., An L., Anderlini L., Andreassi G., Andreotti M., Andrews J. E., Appleby R. B., Archilli F., d’Argent P., Arnau Romeu J., et al. (2017), Updated branching fraction measurements of B(s)0 → KS0h+h′ − decays, in Journal of High Energy Physics, 2017(11), 27-27.
Updated branching fraction measurements of B(s)0 → KS0h+h′ − decays
Aaij R., Adeva B., Adinolfi M., Ajaltouni Z., Akar S., Albrecht J., Alessio F., Alexander M., Ali S., Alkhazov G., Alvarez Cartelle P., Alves A. A., Amato S., Amerio S., Amhis Y., An L., Anderlini L., Andreassi G., Andreotti M., Andrews J. E., Appleby R. B., Archilli F., d’Argent P., Arnau Romeu J., et al. (2017), Updated branching fraction measurements of B(s)0 → KS0h+h′ − decays, in Journal of High Energy Physics, 2017(11), 27-27.
Status of the scalar singlet dark matter model
Athron Peter, Balázs Csaba, Bringmann Torsten, Buckley Andy, Chrząszcz Marcin, Conrad Jan, Cornell Jonathan M., Dal Lars A., Edsjö Joakim, Farmer Ben, Jackson Paul, Kahlhoefer Felix, Krislock Abram, Kvellestad Anders, McKay James, Mahmoudi Farvah, Martinez Gregory D., Putze Antje, Raklev Are, Rogan Christopher, Saavedra Aldo, Savage Christopher, Scott Pat, Serra Nicola, et al. (2017), Status of the scalar singlet dark matter model, in The European Physical Journal C, 77(8), 568-568.
Measurement of the phase difference between short- and long-distance amplitudes in the $${{B} ^+} \!\rightarrow {{{K}} ^+} {\mu ^+\mu ^-} $$ B + → K + μ + μ - decay
Aaij R., Adeva B., Adinolfi M., Ajaltouni Z., Akar S., Albrecht J., Alessio F., Alexander M., Ali S., Alkhazov G., Alvarez Cartelle P., Alves A. A., Amato S., Amerio S., Amhis Y., An L., Anderlini L., Andreassi G., Andreotti M., Andrews J. E., Appleby R. B., Archilli F., d’Argent P., Arnau Romeu J., et al. (2017), Measurement of the phase difference between short- and long-distance amplitudes in the $${{B} ^+} \!\rightarrow {{{K}} ^+} {\mu ^+\mu ^-} $$ B + → K + μ + μ - decay, in The European Physical Journal C, 77(3), 161-161.
Search for the rare decay $B^{+} \rightarrow {\mu}^{+}{\mu}^{-}{\mu}^{+}{\nu}_{{\mu}}$
Aiij Roel, Owen Patrick et al., Search for the rare decay $B^{+} \rightarrow {\mu}^{+}{\mu}^{-}{\mu}^{+}{\nu}_{{\mu}}$, in Eur. Phys. J., xxx.
Summary of the 2018 CKM working group on semileptonic and leptonic $b$-hadron decays
BouchardChristopher, CaoLu, OwenPatrick, Summary of the 2018 CKM working group on semileptonic and leptonic $b$-hadron decays, in 10th International Workshop on the CKM Unitarity Triangle (CKM 2018) Heidelb, International Workshop on the CKM Unitarity Triangle, arXiv:1902.09412.

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
WIN2019. The 27th International Workshop on Weak Interactions and Neutrinos Talk given at a conference B-flavour anomalies in b->sll and b->clnu transitions at LHCb 05.06.2019 Bari, Italy García Pardiñas Julián;
(Re)interpreting the results of new physics searches at the LHC Talk given at a conference Challenges and benefits of auxiliary material LHCb can provide 02.06.2019 London, Great Britain and Northern Ireland Owen Patrick;
Phenomenology Symposium 2019 Talk given at a conference Flavour anomalies and other highlights from B-physics 06.05.2019 Pittsburgh, United States of America Serra Nicola;
La Thuile 2019 - Les Rencontres de Physique de la Vallée d'Aoste Talk given at a conference CINCO: Searches for NP with tare, semileptonic, and radiative decays of heavy-flavour hadrons at the LHC 13.04.2019 La Thuile, Italy García Pardiñas Julián;
HL/HE-LHC Physics Workshop Talk given at a conference Experimental prospects in flavour 01.03.2019 CERN, Geneva, Switzerland Owen Patrick;
26th International Conference on Supersymmetry and Unification of Fundamental Interactions Talk given at a conference CP violation in B decays at LHCb”, on behalf of LHCb 23.07.2018 Barcelona, Spain García Pardiñas Julián;
Particle Physics Seminar Individual talk Flavour anomalies and the quest for New Physics at LHCb 31.05.2018 Basel, Switzerland Serra Nicola;
Beauty 2018 Talk given at a conference R(D*) and friends 06.05.2018 Elba Island, Italy Owen Patrick;
Towards the Ultimate Precision in Flavour Physics workshop Talk given at a conference Experimental approaches to constrain charm loops 16.04.2018 Warwick, Great Britain and Northern Ireland Owen Patrick;
Challenges in semileptonic B decays Talk given at a conference Lambda_b semileptonic decays @ LHCb 09.04.2018 Mainz, Germany Owen Patrick;
b→sℓℓ 2018: 6th Workshop on Rare Semileptonic B Decays Talk given at a conference Direct measurements of Wilson coefficients and LFU test in B → K*ll decay 20.02.2018 Munich, Germany Mauri Andrea;
b→sℓℓ 2018: 6th Workshop on Rare Semileptonic B Decays Talk given at a conference Prospects for data-driven determination of hadronic matrix element in B → K*µµ decay 20.02.2018 Munich, Germany Mauri Andrea;
Implications of LHCb measurements and future prospects Talk given at a conference Prospects for model-independent data-driven analyses of the decay B→K∗μμ 08.11.2017 CERN - Geneva, Switzerland Mauri Andrea;
Physics Colloquium - NUST MISis Individual talk Flavour anomalies and the quest for New Physics 09.10.2017 Moscow, Russia Serra Nicola;


Communication with the public

Communication Title Media Place Year
Media relations: print media, online media Beauty quarks test lepton universality CERN Courier International 2018
Talks/events/exhibitions The LHCb experiment and the quest for New Physics International 2018

Associated projects

Number Title Start Funding scheme
185050 High Precision Flavour Physics at LHCb 01.04.2019 Project funding (Div. I-III)
144674 Rare decays of B-mesons and the physics of the early Universe 01.07.2013 SNSF Professorships
182622 Flavour: a portal to discover new physics 01.04.2019 Project funding (Div. I-III)

Abstract

Despite its great success in describing microscopic phenomena, it is widely accepted that the Standard Model of particle physics is not a complete theory. In the past decades a large number of extensions of the Standard Model have been proposed. All of them predict the existence of new particles that might have played a crucial role in the high energy phase of the early Universe.At present we do not have a clear indication of the masses of these new particles and the energy scale of physics beyond the Standard Model. While the results of direct searches at the LHC direct-detection experiments have mainly confirmed the spectacular success of the Standard Model, there are intriguing discrepancies in the flavour sector which seem to form a coherent pattern. These anomalies consist of the observable P5' in B->K*mumu and the lepton universality breaking ratios R(K) and R(D(*)).The first measurement of P5' was part of my original SNF Professorship proposal and the analysis was completely developed and carried out at the University of Zurich (UZH). In addition, we had a leading role in confirming the P5' anomaly with the full dataset collected in RUN1 by LHCb. We are presently having a key role in measuring other observables that could confirm the R(K) deviation.This proposal is the Follow-up request of my SNF Professorship for two additional years. The main goal of the proposal is the conclusive understanding of the P5' and R(K) anomalies. This will require a set of new measurements, such as angular observables in the decay B0->K*ee. We will also develop a technique that will allow to Wilson coefficients and charm-loop contribution in B->K*ll directly from data. These measurements will conclusively test if these anomalies are due to new physics. Furthermore, searches for new sources of CP asymmetries in addition to that predicted by the Standard Model are among the main goals of current particle physics. In particular, studies involving decays of beauty baryons to purely hadronic final states became experimentally accessible only recently with the start of LHCb. First asymmetry measurements in multi-body charmless decays have been carried out by our group. These results motivated further studies in the area, which culminated with the first evidence of asymmetry between baryonic matter and antimatter in charmless decays, recently reported by LHCb (submitted to Nature Physics journal).This has an extraordinary impact to the field and further measurements with other multi-body beauty baryon decays are compulsory to confirm such observation. In this research proposal I will describe a set of measurements and phenomenological papers that will allow to make conclusive progress in understanding the Flavour Anomalies and will allow to confirm the first hint of CP violation in B-baryons observed by LHCb.
-