2019 Winter institute on Axions in Astrophysics and Cosmology

21 Jan 2019, 10:00 → 31 Jan 2019, 18:00 Europe/Rome

INFN-LNF, Aula Seminari

Enrico Nardi (LNF)

Aim of the meeting:

This informal meeting is intended for extensive discussions on 

astrophysical and cosmological implications of Axions.

A certain number of more formal seminars will be open to the 

general audience: 

 

 

Seminars:

 

 

Monday 21/01 2:30pm        Enrico Nardi (INFN-LNF) 

"Astrophobic Axions"

 

Monday 21/01 3:00pm        Fred Bjorkeroth  (INFN-LNF) 

"Peccei-Quinn Symmetry as a Flavor Symmetry"

 

Tuesday 22/01   2.30pm:         Luca Visinelli (Uppsala University)
"Future Challenges for Axion Physics" 

Wednesday 23/01 2:30pm:      Maurizio Giannotti (Barry University)
"Bounds and Hints on Axions from Stars" 

 

Thursday 24/01, 2:30pm 
Meeting: "The KLASH scientific case"

(For the KLASH Conceptual Design report)

                              

Monday, 21 January

1 Astrophobic Axions

Reliable estimates of the allowed range for axion couplings to photons, nucleons and electrons are of major importance for determining the viable axion mass window as well as to focus experimental axion searches.
We show that in a class of generalized DFSZ axion models with generation dependent Peccei-Quinn charges the axion
couplings to nucleons and electrons can be simultaneously suppressed, thus relaxing the limits on the axion mass from the SN1987A burst duration and from white dwarf cooling.

Speaker: Enrico Nardi

Electrophobia.pdf

Nardi-WinterInstitute2019-1.key

Nardi-WinterInstitute2019-1.pdf

2 Peccei-Quinn Symmetry as a Flavor Symmetry

There has been recent interest in possible connections between a Peccei-Quinn (PQ)
symmetry and quark flavour structures. I describe how a generic
generation-dependent U(1) symmetry acting on the quark Yukawa operators can reduce
the number of free parameters in the quark sector. The maximal reduction
compatible with CP violation yields nine real parameters and one phase, which
matches the number of physical observables, implying that such models have no free
parameters. This has several interesting consequences: (i) there are only two
inequivalent textures, each one giving rise to six different models depending on
quark flavour assignments, (ii) the U(1) symmetries that generate these textures
all have a QCD anomaly, and hence are PQ symmetries, (iii) the resultant axion has
flavour-violating couplings to quarks, which can be probed in meson decays, (iv)
in some cases the contributions to the QCD anomaly of two generations cancels out,
opening up the possibility that the axion coupling to nucleons is strongly
suppressed.

Speaker: Fredrik Bjorkeroth (INFN-LNF)

Tuesday, 22 January

3 Future challenges for Axion Physics

In this talk, I want to provide with some topics that I consider interesting to be explored in the near future. In particular, I will discuss a few ideas for small and big projects that could be developed in relation with axion physics, with a particular attention to the role of substructures.

Speaker: Luca Visinelli

Visinelli_Informal_2019.pdf

Wednesday, 23 January

4 Bounds and Hints on Axions from Stars

Stars are powerful laboratories to study light, weakly interactive particles. In particular, considerations about stars and stellar evolution have led to strong bounds on axion like particles (ALPs), hidden photons, anomalous electromagnetic properties of neutrinos, etc. More recently, observations of excessive stellar energy losses have led to the appealing idea that new-physics (most likely, ALPs) may be playing a role in stellar cooling. I will review the stellar bounds and hints on ALPs and discuss the current experimental potential to probe the hinted parameter space.

Speaker: Maurizio Giannotti

Giannotti_Frascati_2019.pdf

Thursday, 24 January

Meeting: "The KLASH scientific case"

Meeting to outline the KLASH scientific case, for the KLASH Conceptual Design Report