Periodic Reporting for period 1 - FSI in hadron decays (Final state interactions in heavy flavour decays)
Reporting period: 2019-03-18 to 2021-03-17
The precision study of complex multibody decays of bottom and charm hadrons has a unique sensitivity to new fundamental particles and interactions that could give rise to the matter-antimatter asymmetry of the universe, or dark matter.
New, vast datasets allow for these studies to be performed with unprecedented experimental precision. However, theoretical uncertainties limit the sensitivity of this approach.
The work carried out by this fellowship allowed us to overcome this limitation by developing novel theoretical tools to describe multibody hadron decays and applied them to the latest datasets in a unique collaboration between theory and experiment.
Society is being beneficent from the fundamental questions I am addressing such as the new mechanisms that explain the asymmetry between matter and anti-matter.
The main objectives of the fellowship were to investigate the importance of final state interactions (FSI) in B three-body decays. In B->hhh (where h are pions or kaons) FSI introduces new strong phases and can act as an important new source of CP violation that can help us explain the matter-antimatter asymmetry observed in hadronic B-hadron decays. It can also reveal new physics.
The second objective focuses on understanding the discrepancies with the Standard Model (SM) by calculating the complete set of FSI effects. We started with B->Kµµ transitions, which very recently measured with all data available in LHCb since 2011 this discrepancy to be three standard deviations from the SM prediction. Our studies include the quantification of hadronic FSI towards a charm intermediated states which are theoretically very challenging to calculates. The information that can be gained about physics beyond the SM is extremely rich, once hadronic effects are understood.
New, vast datasets allow for these studies to be performed with unprecedented experimental precision. However, theoretical uncertainties limit the sensitivity of this approach.
The work carried out by this fellowship allowed us to overcome this limitation by developing novel theoretical tools to describe multibody hadron decays and applied them to the latest datasets in a unique collaboration between theory and experiment.
Society is being beneficent from the fundamental questions I am addressing such as the new mechanisms that explain the asymmetry between matter and anti-matter.
The main objectives of the fellowship were to investigate the importance of final state interactions (FSI) in B three-body decays. In B->hhh (where h are pions or kaons) FSI introduces new strong phases and can act as an important new source of CP violation that can help us explain the matter-antimatter asymmetry observed in hadronic B-hadron decays. It can also reveal new physics.
The second objective focuses on understanding the discrepancies with the Standard Model (SM) by calculating the complete set of FSI effects. We started with B->Kµµ transitions, which very recently measured with all data available in LHCb since 2011 this discrepancy to be three standard deviations from the SM prediction. Our studies include the quantification of hadronic FSI towards a charm intermediated states which are theoretically very challenging to calculates. The information that can be gained about physics beyond the SM is extremely rich, once hadronic effects are understood.
The research can be divided into two main Work package (WP) related to the processes: B->πππ and B->Kµµ, between theory and experiment.
Is important to point that one of the two years of this fellowship was under the Covid-19 pandemic. And this had a huge impact on my research. On one side I lost the opportunity to interact closely with my direct collaborators, and even the online interaction suffers from the lack of time on their side due to online teaching and family duties. On the other side, all conferences and workshops were lifted and after a long period, some were replaced by online-only presentations. This impacts the exchange of knowledge and the dissemination of the products of my work. The dissemination to the general public also was affected, I had 2 talks (pint of science and Soapbox) postponed and they will happen this year online.
Even though, in total, I am the main and corresponding authors of 5 scientific papers (2 phenomenological and 3 experimental) and 3 outreach ones.
1st period
During the 1st semester of the fellowship, I worked directly with LHCb data to perform a study of the quantum mechanical amplitude structure of B->πππ transitions. In this analysis, I included the rescattering contribution from ππ -> KK that was shown to be a source of Charge Parity (CP) violation beyond those predicted in the SM. sWP1 and sWP2 for B->πππ were delivered and the milestone E1 was achieved with the submission of two papers. I also work directly on an outreach paper, published at CERN-Curie Magazine.
Final amends to the experimental paper in the processes D_>KKK, which I work directly on writing and developing the analysis.
2nd period
I focus on delivering the phenomenological studies on FSI calculations, both applying the charm rescattering model with DD->ππ to B->πππ and developing a SU(3) meson-meson interactions model to be used in different B and D three-body LHCb amplitude analysis. And by the end of this period, I had delivered WP1.2 and made considerable progress in the direction of WP1.1. I finished the novel approach on charm rescattering contribution to B->πππ via DD->ππ rescattering in a triangle loop. The results we organized in a paper with my collaborators which were one of the Milestones in T1.
In October, I started cosupervising a Master Science student. The idea is that the student implements my ππ scattering model as a 4th option. At the moment he is writing the theses.
I also taught a lecture course.
3rd period
This period coincides with the start of the Covid-19 pandemic. During this period I finalize the work on SU(3) meson -meson interaction and wrote the paper which was a milestone T1/T2.
This period I focus on WP.2 developing a charm rescattering model to B->Kµµ, starting with a phenomenological model to DD->µµ. This work has been developed in collaboration with Konstatinos Petridis (Bristol Uni) and Roman Zwicky (University of Edinburgh) and by the end of this period, WP2.1 was delivered.
4th period
In the last period, I work mainly on the contribution of the charm rescattering to B->Kµµ.
Unfortunately, the phenomenological work is not finished yet but we have great progress and WP2.1 and WP2.2 were finished. I am just writing the paper at the moment.
From scientific communication, also an important part of the dissemination project, I had presented the work carryout by this fellowship in 9 conferences and workshops, in which 6 were before the corona pandemic including a plenary talk in Hadrons 2019, one of the main conference in the field. And 3 were online presentations. I also was invited to present 6 long seminars in particle physics groups from different universities in the UK and abroad, and only one was online.
For Public engagement, I had participated on several University activities, but the main ones were on EU corner of scientists and “talk with a scientist” totem at the FUTURES event in 2019. In 2020, it was online and at this time I made storytelling about the origin of the anti-matter. Finally, due to the Pandemic situation, I engage in an outreach project called “Covid-19 Interdisciplinary Action" (acaocovid19.org)” which result in 2 outreach papers.
Is important to point that one of the two years of this fellowship was under the Covid-19 pandemic. And this had a huge impact on my research. On one side I lost the opportunity to interact closely with my direct collaborators, and even the online interaction suffers from the lack of time on their side due to online teaching and family duties. On the other side, all conferences and workshops were lifted and after a long period, some were replaced by online-only presentations. This impacts the exchange of knowledge and the dissemination of the products of my work. The dissemination to the general public also was affected, I had 2 talks (pint of science and Soapbox) postponed and they will happen this year online.
Even though, in total, I am the main and corresponding authors of 5 scientific papers (2 phenomenological and 3 experimental) and 3 outreach ones.
1st period
During the 1st semester of the fellowship, I worked directly with LHCb data to perform a study of the quantum mechanical amplitude structure of B->πππ transitions. In this analysis, I included the rescattering contribution from ππ -> KK that was shown to be a source of Charge Parity (CP) violation beyond those predicted in the SM. sWP1 and sWP2 for B->πππ were delivered and the milestone E1 was achieved with the submission of two papers. I also work directly on an outreach paper, published at CERN-Curie Magazine.
Final amends to the experimental paper in the processes D_>KKK, which I work directly on writing and developing the analysis.
2nd period
I focus on delivering the phenomenological studies on FSI calculations, both applying the charm rescattering model with DD->ππ to B->πππ and developing a SU(3) meson-meson interactions model to be used in different B and D three-body LHCb amplitude analysis. And by the end of this period, I had delivered WP1.2 and made considerable progress in the direction of WP1.1. I finished the novel approach on charm rescattering contribution to B->πππ via DD->ππ rescattering in a triangle loop. The results we organized in a paper with my collaborators which were one of the Milestones in T1.
In October, I started cosupervising a Master Science student. The idea is that the student implements my ππ scattering model as a 4th option. At the moment he is writing the theses.
I also taught a lecture course.
3rd period
This period coincides with the start of the Covid-19 pandemic. During this period I finalize the work on SU(3) meson -meson interaction and wrote the paper which was a milestone T1/T2.
This period I focus on WP.2 developing a charm rescattering model to B->Kµµ, starting with a phenomenological model to DD->µµ. This work has been developed in collaboration with Konstatinos Petridis (Bristol Uni) and Roman Zwicky (University of Edinburgh) and by the end of this period, WP2.1 was delivered.
4th period
In the last period, I work mainly on the contribution of the charm rescattering to B->Kµµ.
Unfortunately, the phenomenological work is not finished yet but we have great progress and WP2.1 and WP2.2 were finished. I am just writing the paper at the moment.
From scientific communication, also an important part of the dissemination project, I had presented the work carryout by this fellowship in 9 conferences and workshops, in which 6 were before the corona pandemic including a plenary talk in Hadrons 2019, one of the main conference in the field. And 3 were online presentations. I also was invited to present 6 long seminars in particle physics groups from different universities in the UK and abroad, and only one was online.
For Public engagement, I had participated on several University activities, but the main ones were on EU corner of scientists and “talk with a scientist” totem at the FUTURES event in 2019. In 2020, it was online and at this time I made storytelling about the origin of the anti-matter. Finally, due to the Pandemic situation, I engage in an outreach project called “Covid-19 Interdisciplinary Action" (acaocovid19.org)” which result in 2 outreach papers.
The two phenomenological papers published during this fellowship bring some striking results that will have a huge impact on the community's understanding of data.
The first one was the confirmation of the charm rescattering as a source of Charge-Parity violation. In our studies on B->πππ, we show that the interference with the charm loop contribution with the tree (and dominate) amplitude with the weak phase is enough to produce the same signature we saw in data. Revealing a new mechanism and also a new investigation branch in amplitude analysis. This effect is shown in the Figure called "CPV_high.pdf" uplouded. This result was published in March 2020 in Physics Letters B.
In the tool kit that can be applied to any B or D decaying to any three-body light mesons combination, with good two-body interaction ingredient for low energy, modeled with ChPT and with n number of resonances with freedon to fit the data. The diagramatic representation of this too kit is presented in the Figure called "Tool_kit.pdf". The "Multibody decay analyses -- a new phenomenological model for meson-meson subamplitude” was published in July at Physical Review D. This is a very important and striking contribution for the community.
The first one was the confirmation of the charm rescattering as a source of Charge-Parity violation. In our studies on B->πππ, we show that the interference with the charm loop contribution with the tree (and dominate) amplitude with the weak phase is enough to produce the same signature we saw in data. Revealing a new mechanism and also a new investigation branch in amplitude analysis. This effect is shown in the Figure called "CPV_high.pdf" uplouded. This result was published in March 2020 in Physics Letters B.
In the tool kit that can be applied to any B or D decaying to any three-body light mesons combination, with good two-body interaction ingredient for low energy, modeled with ChPT and with n number of resonances with freedon to fit the data. The diagramatic representation of this too kit is presented in the Figure called "Tool_kit.pdf". The "Multibody decay analyses -- a new phenomenological model for meson-meson subamplitude” was published in July at Physical Review D. This is a very important and striking contribution for the community.