Conveners
Hadrons and physics beyond the standard model: Session 1
- Frank Maas (Helmholtz-Institut Mainz)
Hadrons and physics beyond the standard model: Session 2
- Mattia Bruno (Universita' di Milano-Bicocca)
Hadrons and physics beyond the standard model: Session 3
- Mikhail Gorshteyn (Mainz University)
Hadrons and physics beyond the standard model: Session 4
- Lorenzo Pagnanini (Gran Sasso Science Institute & INFN - LNGS)
Hadrons and physics beyond the standard model: Session 5
- Claudia Tomei (Istituto Nazionale di Fisica Nucleare)
- Pablo Roig (Cinvestav, Mexico City, Mexico)
Hadrons and physics beyond the standard model: Session 7
- Javier Virto (U. Barcelona, ICCUB)
Hadrons and physics beyond the standard model: Session 8
- Elisabetta Spadaro Norella (Istituto Nazionale di Fisica Nucleare)
Abstract: Over the last decade lattice QCD methodology has matured significantly
and precise first-principles calculations of the hadronic contributions to the muon g-2
are now possible. I will summarize the status of the hadronic light-by-light and the
hadronic vacuum polarization contributions and I will give an outlook on expected future
progress.
In this talk, we review the recent progress on the numerical determination of the Hadronic Light-by-Light contribution to the anomalous magnetic moment of the muon discussing the role of experimental data on the accuracy of its determination.
The hadronic contributions to the Standard Model prediction of the muon g-2 have been determined using data-driven approaches. This talk will give an overview of the hadronic cross section measurements relevant for the hadronic vacuum polarization contribution and the transition form factor measurements relevant for the hadronic light-by-light contribution.
Radiative corrections to one-meson tau decays have become relevant to test CKM unitarity, lepton universality, and non-standard interactions. In this work, we compute the radiative corrections to the $\tau^-\to (P_1,P_2)^-\nu_\tau$ ($P_{1,2}=\pi, K$) decays for the first time using Resonance Chiral Theory (R$\chi$T).
The R value, defined as the ratio of inclusive hadronic cross section over dimu cross-section from electron-positron annihilation, is an important quantity that contributes to the SM prediction of the muon anomalous magnetic moment, and in the determination of the QED running coupling constant evaluated at the Z pole. At BESIII, the R value is measured with a total of 14 data points with the...
Indirect searches for new physics beyond the standard model employ precision measurements of low energy observables like for example the weak mixing angle expressed as $\sin^2 \theta_W$. There are several possibilities to measure this quantity, one is the measurement of a parity-violating asymmetry in elastic electron-proton scattering.
The P2 experiment at the upcoming Mainz energy...
The future MOLLER experiment will measure the parity-violating asymmetry forMøller scattering improving on the previous measurement E158 at SLAC by a factor of five. This measurement will yield the most precise measurement of the weak mixing angle at energies well below the scale of electroweak symmetry breaking. This new result would be sensitive to the interference of the electromagnetic...
Coherent elastic neutrino-nucleus scattering (CEνNS) is a process in which MeV energy scale neutrinos scatter on a nucleus, which behaves as a single particle. Within the Standard Model (SM), CEνNS is described by the neutral current interaction of neutrinos and quarks, and, due to the nature of couplings, its cross-section is proportional to the neutron number squared. In 2017, the COHERENT...
Neutron EDM (nEDM) is one of the most promising ways to probe CP-violating quark and gluon interactions and constrain potential extensions of the Standard Model. While nucleon models and low-energy theories provide some ballpark estimates for the nEDM sensitivity to these interactions, they may vary by an order of magnitude or more. Such theoretic uncertainties can only be eliminated by ab...
The NA62 experiment at CERN collected the world’s largest dataset of charged
kaon decays in 2016-2018, leading to the first measurement of the branching
ratio of the ultra-rare K+ → π+ν ̄ν decay, based on 20 candidates, and presented
in 2021. In this talk the NA62 experiment reports new results from analyses
of K+ → π+μ+μ− and K+ → π+γγ decays, using a data sample recorded in
2017–2018....
With the large datasets on 𝑒+𝑒−-annihilation at the 𝐽/𝜓 and 𝜓(3686) resonances collected at the BESIII experiment, multi-dimensional analyses making use of polarization and entanglement can shed new light on the production and decay properties hyperon-antihyperon pairs. In a series of recent studies performed at BESIII, significant transverse polarization of the (anti)hyperons has been...
The axion is a hypothetical new particle that could explain the absence of CP violation in QCD and has a very rich cosmological phenomenology. In particular a population of thermally produced axions is expected to exist, in addition to a cold dark matter population. I discuss a new conservative bound on the axion mass, from production in the early universe through scattering with pions below...
BDX-MINI is a beam dump experiment performed at Jefferson Lab, aimed at searching for Light Dark Matter in the MeV-GeV mass range. Dark Matter is expected to be produced by the interaction of CEBAF high-intensity 2.176 GeV beam with the Hall A beam dump at Jefferson Lab.
The detector, installed in a well located 22 m downstream of the Hall-A beam dump, consists of a PbWO4 electromagnetic...
Dark Matter (DM) is one of the biggest unanswered questions in modern physics. Despite the astrophysical and cosmological observations suggesting its existence, to date no particle physics experiment detected an unequivocal DM signal, shedding light on its fundamental properties. Among the different hypothetical DM models, vector-mediated Light Dark Matter (LDM) is a compelling paradigm,...
Neutrinoless double-beta decay ($0\nu\beta\beta$) is a hypothetical nuclear decay that is only possible if the neutrino is a Majorana fermion. This decay can be mediated either by a light Majorana neutrino propagating between two electroweak current insertions or by higher-dimension short-distance operators that appear in some beyond the Standard Model theories. Experimental searches for...
Since the discovery of neutrino oscillations, the search for neutrinoless double beta decay stands among the highest priorities for understanding the nature of neutrinos and the origin of their mass. The experimental observation of this lepton-number-violating process, only hypothesised so far, would demonstrate that neutrinos are Majorana fermions, equal to their own antiparticles. This in...
The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double-beta (0$\nu\beta\beta$) decay that has been able to reach the one-tonne mass scale. The detector, located at the LNGS in Italy, consists of an array of 988 TeO$_2$ crystals arranged in a compact cylindrical structure of 19 towers. CUORE began its first physics data...
Hadronic and radiative decays of light mesons decays offer a privileged environment to test QCD and search for physics beyond the Standard Model.
A new generation of precision experiments in hadron physics will soon offer new data that will have an impact on determinations of fundamental QCD parameters, such as the ratio of light quark masses or the $\eta$-$\eta^{\prime}$ mixing parameters,...
Precision tests of the Standard Model with beta decays and unitarity of the Cabibbo-Kobayashi-Maskawa quark mixing matrix offer a way to search for BSM signals, which is competitive and complementary to the collider searches. Currently, the CKM top-row unitarity constraint shows a deficit $\Delta_u=|V_{ud}|^2+|V_{us}|^2+|V_{ub}|^2-1=-0.0015(7)$ which may point to possible New Physics...
The system of light pseudoscalar mesons π0, η and ηꞌ provide a unique laboratory to probe fundamental QCD symmetries at the confinement scale. While π0 and η are Goldstone bosons due to spontaneous chiral symmetry breaking, ηꞌ is not due to an axial U(1) anomaly coupling to the gluon field. The chiral anomaly coupling to the electromagnetic field drives the two-photon decays of these mesons....
The sensitivity of the rare decays $\eta^{(\prime)}\to\pi^{0}\gamma\gamma$ and $\eta^{\prime}\to\eta\gamma\gamma$ to signatures of a leptophobic $B$ boson in the MeV-GeV mass range is analyzed in this work.
By adding an explicit $B$-boson resonance exchange, $\eta\to B\gamma\to\pi^{0}\gamma\gamma$, to the Standard Model contributions from vector and scalar meson exchanges,and employing...
Precision measurements of forbidden β-decays are a crucial benchmark for Nuclear Physics calculations, which in turn play a pivotal role in Astroparticle Physics. In particular, these processes could clarify the long-standing issue of the axial coupling constant (gA) quenching in nuclear medium, which enters the theory when the hadronic current is renormalized at the nucleon level and...
Neutrinoless double beta decay is a crucial probe for physics beyond the Standard Model. While it is usually interpreted as being mediated by the exchange of light Majorana neutrinos, non-standard contributions to neutrinoless double beta decay arise in many well-motivated scenarios of New Physics that aim to explain the lightness of neutrinos, such as sterile neutrinos, Left-Right Symmetry...
This talk is based on the main results of the published article JHEP 04 (2022) 152. Model independent bounds on new physics are obtained using semi-leptonic tau decays as observables. To do this, We determine the dependence of several inclusive and exclusive τ observables on the Wilson coefficients of the low-energy effective theory describing charged-current interactions between light...
In the context of the anomalous magnetic moment of the muon, the hadronic contribution plays a crucial role, especially concerning the error budget estimation. Currently, lattice QCD simulations confront the dispersive calculations based on e+e- hadronic cross sections. The new MUonE experimental proposal pretends to shed light on that situation. Still, a powerful method to extract the desired...
Evidence for electroweak-scale Dark Matter (DM) particles arising from direct searches has proven to be extremely elusive so far. However, the existence of light (sub-GeV) particles could also be investigated searching for rare events at accelerators. A simple possibility for light DM is that its constituents belong to some Hidden Sector, uncharged under the Standard Model (SM) forces and...
The anomaly observed in the opening angle and invariant mass distributions of e$^+$e$^−$ pairs produced in the decays of excited $^8$Be, $^4$He and $^{12}$C nuclei [1-3] can be interpreted with the creation and subsequent decay of a particle of mass approximately 17 MeV which has been named X17.
Along the years, several light particles have been postulated by theoretical extensions of the...
I will tell the story (or part of it) of rare B decays of the last ~10 years.
In the SM, the electroweak bosons couple to the three lepton families with the same strength, the only difference in their behaviour being due to the difference in mass. In recent years, some deviations have been found in measurements of the ratios of branching fractions for $b$-hadrons decaying into final states with different lepton flavours. This talk presents recent results of lepton...
We benefit from the lattice QCD determination of the Standard Model (SM) form factors for the $\bar B_s\to D_s^{*}$ and $\bar B_s\to D_s$ semileptonic decays carried out by the HPQCD collaboration in Refs. Phys. Rev. D 105, 094506 (2022) and Phys. Rev. D 101, 074513 (2020), and the heavy quark effective theory (HQET) relations for the analogous $B\to D^{(*)}$ decays obtained by F.U....
The BESIII experiment has collected 2.6B psi(2S) events and 10B J/psi events. The huge data sample provide an excellent chance to search for rare processes in charmonium decays. In this talk, we report the recent search for J/psi->D^-e+nu_e, psi(2S)->Lambda_c anti-Sigma^-. The big charmonium sample also produce millions of hyperons, which is used to study the weak decay of \Sigma^-...
Neutrinoless double-beta decay (0nbb) is a beyond standard model atomic decay which involves atomic, nuclear and particle physics. Since these different fronts naturally involve separated energy scales, effective field theory (EFT) provides a natural framework to study this process.
In this talk I will present some EFT ideas to study 0nbb. In particular, I will focus on EFTs for the...
The search for neutrinoless double beta (0$\nu\beta\beta$) decay is considered as the most promising way to prove the Majorana nature of neutrinos as well as to give an indication on the mass hierarchy and on the absolute mass scale. The discovery of 0$\nu\beta\beta$ decay would moreover open the way for theories predicting the observed matter anti-matter asymmetry of the Universe being a...
The presentation aims at describing an overview of the activities related with the NUMEN project at INFN – LNS. NUMEN is an international collaboration which proposes an innovative technique to give information on the nuclear matrix elements entering the expression of the decay rate of double beta decay by cross section measurements of heavy-ion induced Double Charge Exchange (HI-DCE)...
The NA62 experiment at CERN took data in 2016–2018 with the main goal of measuring the $K^+ \rightarrow \pi^+ \nu \bar\nu$ decay. The NA62 dataset is also exploited to search for light feebly interacting particles produced in kaon decays. Searches for $K^+\rightarrow e^+ N$, $K^+ \rightarrow \mu^+ N$ and $K^+ \rightarrow \mu^+ \nu X$ decays, where N and X are massive invisible particles, are...
