Electromagnetic Form Factor of Doubly-Strange Hyperon

The standard model of particle physics is a well-tested theoretical framework, but there are still some issues that deserve experimental and theoretical investigation. The Ξ resonances with strangeness S=−2, the so-called doubly-strange hyperon, can provide important information to further test the standard model by studying their electromagnetic form factors, such as probing the limitation of the quark models and spotting unrevealed aspects of the QCD description of the structure of hadron resonances. In this work, we review some recent studies of the electromagnetic form factors on doubly-strange hyperons in pair production from positron–electron annihilation experiment.

A road towards a beyond the Standard Model model

In this talk we describe examples of renormalizable strongly interacting field theories where chiral symmetry, broken at the UV cutoff by the presence of some irrelevant d > 4 operators in the fundamental Lagrangian, is recovered at low energy owing to the tuning of certain Lagrangian parameters. The interference of UV effects with IR features coming from the spontaneous breaking of the recovered chiral symmetry yields non perturbatively generated elementary fermion masses parametrically expressed by formulae of the kind mq ~ Cq(α)ΛRGI with α the gauge coupling constant and ΛRGI the RGI scale of the theory. Upon introducing EW interactions, this mechanism can be extended to give mass to EW bosons and leptons and can thus be used as an alternative to the Higgs scenario. In order to give the top quark and the weak gauge bosons a mass of the phenomenologically correct order of magnitude, the model must necessarily include (yet unobserved) super-strongly interacting massive fermions endowed, besides ordinary Standard Model interactions, with super-strong interactions with a RGI scale, ΛT ΛQCD in the few TeV range. Though limited in its scope (here we ignore hypercharge and leptons and discuss only the case of one family neglecting weak isospin splitting), the model opens the way to a solution of the naturalness problem and an understanding of the fermion mass hierarchy.

Direct CP violation and the ΔI = 1/2 rule in K → ππ decay in the Standard Model

We discuss the RBC & UKQCD collaborations’ recent [1] lattice calculation of ϵ′, the measure of direct CP-violation in kaon decays. This result significantly improves on our previous 2015 calculation, with nearly 4× the statistics and more reliable systematic error estimates. We discuss how our results demonstrate the Standard Model origin of the ΔI = 1/2 rule, and present our plans for future calculations.

Long-lived heavy neutral leptons at the LHC: four-fermion single-NR operators

Interest in searches for heavy neutral leptons (HNLs) at the LHC has increased considerably in the past few years. In the minimal scenario, HNLs are produced and decay via their mixing with active neutrinos in the Standard Model (SM) spectrum. However, many SM extensions with HNLs have been discussed in the literature, which sometimes change expectations for LHC sensitivities drastically. In the NRSMEFT, one extends the SM effective field theory with operators including SM singlet fermions, which allows to study HNL phenomenology in a “model independent” way. In this paper, we study the sensitivity of ATLAS to HNLs in the NRSMEFT for four-fermion operators with a single HNL. These operators might dominate both production and decay of HNLs, and we find that new physics scales in excess of 20 TeV could be probed at the high-luminosity LHC.

Effect of Systematic Uncertainty Estimation on the Muon g - 2 Anomaly

The statistical significance that characterizes a discrepancy between a measurement and theoretical prediction is usually calculated assuming that the statistical and systematic uncertainties are known. Many types of systematic uncertainties are, however, estimated on the basis of approximate procedures and thus the values of the assigned errors are themselves uncertain. Here the impact of the uncertainty on the assigned uncertainty is investigated in the context of the muon g - 2 anomaly. The significance of the observed discrepancy between the Standard Model prediction of the muon’s anomalous magnetic moment and measured values are shown to decrease substantially if the relative uncertainty in the uncertainty assigned to the Standard Model prediction exceeds around 30%. The reduction in sensitivity increases for higher significance, so that establishing a 5σ effect will require not only small uncertainties but the uncertainties themselves must be estimated accurately to correspond to one standard deviation.

Data-driven approaches to the evaluation of hadronic contributions to the (g − 2)μ

In this talk I reviewed the data-driven theoretical calculation of the hadronic contributions to the anomalous magnetic moment of the muon in the Standard Model mainly as it has been presented in the White Paper, but also including the most recent developments. All this is presented in the light of the new measurement of (g − 2)μ recently released by the Fermilab experiment, which led to an increase of the discrepancy with the Standard Model from 3.7 to 4.2σ.

B-anomalies from flavorful U(1)$$'$$ extensions, safely

Abstract$$U(1)^\prime $$ U ( 1 ) ′ extensions of the standard model with generation-dependent couplings to quarks and leptons are investigated as an explanation of anomalies in rare B-decays, with an emphasis on stability and predictivity up to the Planck scale. To these ends, we introduce three generations of vector-like standard model singlet fermions, an enlarged, flavorful scalar sector, and, possibly, right-handed neutrinos, all suitably charged under the $$U(1)^\prime $$ U ( 1 ) ′ gauge interaction. We identify several gauge-anomaly free benchmarks consistent with $$B_s$$ B s -mixing constraints, with hints for electron-muon universality violation, and the global $$b \rightarrow s$$ b → s fit. We further investigate the complete two-loop running of gauge, Yukawa and quartic couplings up to the Planck scale to constrain low-energy parameters and enhance the predictive power. A characteristic of models is that the $$Z^\prime $$ Z ′ with TeV-ish mass predominantly decays to invisibles, i.e. new fermions or neutrinos. $$Z^\prime $$ Z ′ -production can be studied at a future muon collider. While benchmarks feature predominantly left-handed couplings $$C_9^{\mu }$$ C 9 μ and $$C_{10}^{\mu }$$ C 10 μ , right-handed ones can be accommodated as well.

Desire

Through the argument that the concept of phase transition also applies to the unfolding of the information processing system that is creation, the author arrives at the phase stage described in the Standard Model of particle physics, where this system and the information flowing through it also form a part that gets coupled to matter and spacetime. The author then concludes that this stage, together with those that came before it, form one complex cybernetic processing system which allows for information to flow back and forth through various feedback and feedforward loops. Further arguments are that the sources for the information flowing through this system are coming from Desire in the broadest sense of the word, as the main, driving feedforward loop; with emotion—as a further explication of motion—as the regulating feedback loop; and that combined they account for the fluctuation called life.