Conveners
Tests of symmetries and conservation laws
- DMITRY BUDKER (Helmholtz Institute Mainz JGU Mainz and UC Berkeley)
- Michael Doser (CERN)
- Antonio Pich (IFIC)
Tests of symmetries and conservation laws
- Michael Doser (CERN)
- DMITRY BUDKER (Helmholtz Institute Mainz JGU Mainz and UC Berkeley)
- Antonio Pich (IFIC)
Description
Information for speakers about talk's duration:
25 min slot= 20 to speak + 5 for questions
20 min slot = 17 to speak + 3 for questions
The Mu2e experiment aims to measure the charged-lepton flavour violating (CLFV) neutrino-less conversion of a negative muon into an electron in the field of an aluminum nucleus. The conversion process results in a monochromatic electron with an energy slightly below the muon rest mass (104.97 MeV). The Mu2e goal is to improve the world’s best limit by SINDRUM II of four orders of magnitude and...
The Belle II experiment is a substantial upgrade of the Belle detector and will operate
at the SuperKEKB energy-asymmetric e+e− collider. The design luminosity of the machine
is 8 × 1035 cm−2s−1 and the Belle II experiment aims to record 50 ab−1 of data, a factor
of 50 more than its predecessor. From February to July 2018, the machine has completed a
commissioning run and main operation of...
Within the Standard Model Effective Field Theory framework, with operators up to dimension 6, we perform a model-independent analysis of the lepton-flavour-violating processes involving tau leptons. Namely, we study hadronic tau decays and $\ell$-$\tau$ conversion in nuclei, with $\ell = e,\mu$. Based on available experimental limits, we establish constraints on the Wilson coefficients of the...
The measurement of a permanent electric dipole moment of the neutron (nEDM), as a CP-violating observable, is one of the main priorities at the low energy frontier of particle physics. A discovery or a highly improved constraint could contribute to our understanding of the baryon asymmetry of the universe. Our international collaboration obtained a new limit on the nEDM with an apparatus...
New physics models with additional CP violation sources are currently being constrained by searches for electric dipole moments (EDMs). Using the stringent limits on their chromo-EDMs, new bounds on the EDM of charm and bottom quarks will be derived. The new limits improve the previous ones by about three orders of magnitude. The implications for different Standard Model extensions will be discussed.
The neutron Electric Dipole Moment (EDM) has always attracted interest as a promising channel for finding new physics. The existence of a neutron EDM would violate CP symmetry given the CPT conservation. This new source of CP violation could explain the baryon asymmetry of the universe. The BeamEDM experiment aims to measure the neutron EDM using a novel technique which overcomes the previous...
Searches for permanent electric dipole moments (EDMs) provide important results to constrain model parameters and promising experiments to potentially reveal beyond Standard Model (SM) physics. A non-zero EDM is a direct manifestation of time-reversal (T) violation, and, equivalently, violation of the combined operation of charge-conjugation (C) and parity inversion (P). Identifying new...
Molecular spectroscopy represents a unique tool in the search for physics beyond the Standard Model and exploration of the fundamental forces of nature. Compared to atoms, molecules can offer more than five orders of magnitude enhanced sensitivity to violations of fundamental symmetries, testing energy scales beyond hundreds of TeV. These effects are further enhanced in radioactive molecules,...
We have made recent progress in studying the short-distance properties of the hadronic light-by-light contribution to the muon $g-2$. The intermediate and short-distance part is a major contributor to the error of the hteoretical prediction, see the white paper [arxiv:2006.04822, Physics Reports 887 (2020) 1-166]. We have recently shown that the massless quark-loop is the first term in a...
The LUXE experiment (LASER Und XFEL Experiment) is a new experiment in planning at DESY Hamburg using the electron beam of the European XFEL. LUXE is intended to study collisions between a high-intensity optical LASER and 16.5 GeV electrons from the XFEL electron beam, as well as collisions between the optical LASER and high-energy secondary photons. The physics objective of LUXE are processes...
The Cosmic Axion Spin Precession Experiments (CASPEr) search for ultralight axion-like dark matter. CASPEr-e is sensitive to the time-varying nuclear electric dipole moment, induced by the electric-dipole moment (EDM) coupling $g_d$. The detection scheme is based on a precision measurement of
$^{207}$Pb solid-state nuclear magnetic resonance in a polarized ferroelectric crystal. We calibrated...
The ASACUSA collaboration at CERN’s Antiproton Decelerator, and the PiHe collaboration at PSI’s 590 MeV ring cyclotron facility have carried out laser spectroscopy of metastable antiprotonic and pionic helium atoms. The latter is a three-body exotic atom composed of a helium nucleus, electron, and negative pion occupying a highly-excited state with principal and orbital angular momentum...
The Standard Model is the most successful theory in physics. However, it does leave several questions open, such as for example the striking matter-antimatter imbalance in the visible Universe, or the origin of dark matter. These questions can be probed by ultra-high precision comparisons of the fundamental properties of protons and antiprotons, like the charge-to-mass ratio or the magnetic...
An observation of neutron-antineutron oscillations, which violate both baryon and baryon-lepton conservation, would constitute a scientific discovery of fundamental importance to physics and cosmology. A stringent upper bound on its transition rate would make an important contribution to our understanding of the baryon asymmetry of the Universe by eliminating the postsphaleron baryogenesis...
Antiprotonic atoms have been fundamental in experiments which made the most precise data on the strong interaction between protons and antiprotons and of the neutron skin of many nuclei thanks to the clean annihilation signal. In most of these experiments, the capture process of low energy antiprotons was done in a dense target leading to a significant suppression of specific transitions...
The ASACUSA experiment aims at a precise measurement of the ground state hyperfine (GSHFS) splitting of antihydrogen with an initial relative precision of $\leq 10^{-6}$ to test the combined CPT symmetry. The Rabi-type measurement will be carried out in a polarized beam of antihydrogen atoms that is synthesized via three-body-recombination (3BR) of positrons and antiprotons at CERN's...
Search for possible violation of combined charge, parity, and time-reversal symmetries is yet another approach for a test of New Physics, therefore a bound state of electron and positron (positronium) as the lightest matter-antimatter system and at the same time aneigenstate of the C and P operators is an unique probe in such endeavour. The test is performed by measurement of angular...
A hydrogen-like atom in which a positive muon ($\mu^+$) and an electron are
bound is called muonium (Mu). The MuSEUM collaboration aims to determine
the muonium’s hyperfine structure (MuHFS) with a precision of 1 ppb, a tenfold
improvement in precision compared to previous experimental results [1]. Since
muonium is a leptonic two-body system, high-precision comparison of
experimental and...
The NA62 experiment at CERN reports new results from the study of the radiative kaon decay K+ -> pi0 e+ nu g (Ke3g), using a data sample recorded in 2017--2018. The sample comprises O(100k) Ke3g candidates with sub-percent background contamination. Preliminary results with the most precise measurement of the Ke3g branching ratio, and a T-asymmetry measurement in the Ke3g decay, are presented.
The BESIII experiment at the electron positron collider BEPCII in Beijing is successfully operating since 2008 and has collected large data samples in the tau-mass region, including the world's largest data samples at the J/Psi and Psi(2S) resonances. The recent observations of hyperon polarisations at BESIII opens a new window for testing CP violation, as it allows for simultaneous production...
The VIP-2 experiment at the Underground Gran Sasso Laboratory (LNGS) aims to
perform high sensitivity tests of the Pauli Exclusion Principle (PEP) for
electrons, and search for a possible small violation. The PEP violation would be a clear indication of physics beyond the Standard Model.
The VIP-2 collaboration performs tests of PEP violation in various configurations.
A first...
Proton decays are sought as manifestation of baryon number violation predicted by Grand Unification. Their amplitudes depend on nonperturbative QCD, and we calculate them on a lattice with chirally symmetric quarks at the physical point for the first time. Our results largely agree with previous determinations done with heavy quark masses. Therefore, our findings solidify evidence against...
The NA62 experiment at CERN collected a large sample of charged kaon decays into final states
with multiple charged particles in 2016-2018. This sample provides sensitivities to rare decays with branching ratios as low as 10-11.
Searches for the lepton number violating K+→π−μ+e+ decay and the lepton flavour violating K+→π+μ−e+ and π0→μ−e+ decays are reported. No evidence for these decays is...
