Violations of CPT invariance can induce neutrino-to-antineutrino transitions. We study this effect for solar neutrinos and use the upper bound on the solar neutrino-to-antineutrino transition probability from the KamLAND experiment to constrain CPT-symmetry-violating coefficients of the general Standard-Model Extension. The long propagation distance from the Sun to the Earth allows us to improve existing limits by factors ranging from about a thousand to $10^{11}$.
Minimal CPT violation has been constrained using observations of neutral-meson oscillations. Violation of CPT symmetry arising from nonminimal operators in the Lagrange density can also occur. A general approach using scalar effective field theory is presented and used to infer the effects of nonminimal CPT violation on neutral-meson oscillations.
It is shown that there is a possibility of violation of CPT symmetry in the Standard Model which does not contradict to the famous CPT theorem. To check this possibility experimentally it is necessary to increase the precision of measurements of the proton and antiproton mass difference by an order of magnitude
This talk at the CPT'19 meeting outlines a few recent developments in Lorentz and CPT violation, with particular attention to results obtained by researchers at the Indiana University Center for Spacetime Symmetries.
A general technique is presented for treating CPT violation in neutral-meson oscillations. The effective field theory for a complex scalar with CPT-violating operators of arbitrary mass dimension is incorporated in the formalism for the propagation and mixing of neutral mesons. Observable effects are discussed, and first measurements of CPT-violating operators of dimension five are extracted from existing experimental results.
This presentation discusses some of the signals for Lorentz violation potentially observable in atomic spectroscopy and clock-comparison experiments. The emphasis of the discussion is on how the angular-momentum quantum numbers of the states involved in the transition determine the properties of the possible sidereal variation of the transition frequency.
An overview of recent progress on testing Lorentz and CPT symmetry using Penning traps is presented. The theory of quantum electrodynamics with Lorentz-violating operators of mass dimensions up to six is summarized. Dominant shifts in the cyclotron and anomaly frequencies of the confined particles and antiparticles due to Lorentz and CPT violation are derived. Existing results of the comparisons of charge-to-mass ratios and magnetic moments involving protons, antiprotons, electrons, and positrons are used to constrain various coefficients for Lorentz violation.
Disentangling violations of CPT from other new-physics effects
我们分析了利用中性介子P0-P0巴系统观测CPT破坏的前景。在声称测量CPT破坏之前，必须能够排除其结果是由于更简单的新物理效应的可能性。特别是，我们必须能够将CPT破坏量与破坏半轻子衰变的Δ P = ΔQ规则的参数分开，并与新物理学对中性介子产生机制的贡献分开。人们可以用单个标记中性介子的半轻子衰变来分离CPT破坏;不幸的是，这种情况在4S剧变中无法实现。对于在相关宇称奇态中产生的P0-P0 bar对，我们证明，通过将双轻子衰变与单轻子衰变相结合，原则上可以明确地提取一个CPT破坏参数。最后，我们开发的形式主义必要的生产机制中描述新的物理效应，这包括级联衰变和违反规则的相关生产。
CPT invariance is one of the most fundamental symmetries in nature and it plays a major role in the formulation of Quantum Field Theory. Although no definitive signal of CPT violation has been observed so far, there are many reasons to carefully investigate various low-energy phenomena that can provide better probes to test CPT symmetry. In this context, neutrino experiments are expected to provide more stringent bounds on CPT invariance violation when compared to the existing bounds from the Kaon system. In this work, we investigate the sensitivity of the upcoming long-baseline experiments: H…
Lorentz- and CPT-violating effects initiating two-body electromagnetic flavor-changing decays of charged leptons are studied in the framework of Lorentz-violating effective field theory. An analysis of data from experiments at the Paul Scherrer Institute and at the Stanford Linear Accelerator measuring the branching ratios of these decays provides 576 constraints on independent flavor-changing effects in the charged-lepton sector, consistent with no Lorentz and CPT violation at the level of parts in $10^{-13}$ GeV$^{-1}$ to $10^{-9}$ GeV$^{-1}$.
When a neutral meson $(P^0 \text{ or } \bar P^0)$ decays to two vector particles, a large number of observables can be constructed from differential decay rate based on the polarization of final state. But, theoretically, all of them are not independent to each other and hence, some relations among observables emerge. These relations have been well studied in the scenario with no $T$ and $CPT$ violation in neutral meson mixing and no direct $CP$ violation as well. In this paper, we have studied the relations among observables in the presence of $T$, $CP$ and $CPT$ violating effects in mixing o…
An overview of recent progress on searches for Lorentz- and CPT-violating signals with confined particles and antiparticles in Penning traps is presented. In the context of the Standard-Model Extension (SME), leading-order shifts in the cyclotron and anomaly frequencies of a confined particle and antiparticle due to Lorentz and CPT violation are provided. The two frequencies are then related to comparisons of charge-to-mass ratios and magnetic moments between particles and antiparticles. Applying reported results from Penning-trap experiments leads to new limits on various coefficients for Lor…
In this conference proceedings, some comments on the present status and recent growth of efforts to find Lorentz and CPT violation are given by extracting metrics from the annually updated "Data Tables for Lorentz and CPT Violation." They reveal that tests span all the sectors of particle and gravitational physics, and have shown remarkable and consistent growth. Through numerous innovations and refinements in experiments, a large body of data has been amassed with ever-increasing precisions. The Tables are available through the Cornell preprint archive at arXiv:0801.0287.
A large number of observables can be constructed from differential decay rate based on the polarization of final state while considering decay of a neutral meson $(P^0 \text{ or } \bar P^0)$ to two vector particles. But all of these observables are not independent to each other since there are only a few independent theoretical parameters controlling the whole dynamics and therefore various relations among observables emerge. In this paper, we have studied the behaviour of observables for neutral meson decaying to two vectors in presence of T and CPT violations in mixing accompanied by both di…
