<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">CPT</mml:mi></mml:math>and Lorentz Tests with Muons

Bluhm, Robert; Kostelecký, V. Alan; Lane, Charles D.

doi:10.1103/physrevlett.84.1098

Cited by 249 publications

(223 citation statements)

References 47 publications

Supporting

Mentioning

211

Contrasting

Unclassified

Order By: Relevance

“…Its formulation at the level of the known elementary particles is a key feature enabling quantitative comparison of a wide array of tests of Lorentz and CPT symmetry. In this context, theoretical studies have been performed to investigate the sensitivity of clockcomparison experiments [9], tests of QED in Penning traps [12], experiments with a spin-polarized torsion pendulum [13], hydrogen-antihydrogen spectroscopy [14], studies of photon birefringence in the vacuum [8,15,16], experiments with muons [17], measurements of neutral-meson oscillations [7,18], studies of the baryon asymmetry [19], and cosmic-ray observations [20].…”

Section: Limit On Lorentz and Cpt Violation Of The Neutron Using A Twmentioning

confidence: 99%

Limit on Lorentz andCPTViolation of the Neutron Using a Two-Species Noble-Gas Maser

et al. 2000

Self Cite

View full text Add to dashboard Cite

A search for sidereal variations in the frequency difference between co-located 129 Xe and 3 He Zeeman masers sets the most stringent limit to date on leading-order Lorentz and CPT violation involving the neutron, consistent with no effect at the level of 10 231 GeV. PACS numbers: 06.30.Ft, 11.30.Cp, 11.30.Er, 84.40.Ik Lorentz symmetry is a fundamental feature of modern descriptions of nature, including both the standard model of particle physics and general relativity. However, these realistic theories are believed to be the low-energy limit of a single fundamental theory at the Planck scale. Even if the underlying theory is Lorentz invariant, spontaneous symmetry breaking might result in small apparent violations of Lorentz invariance at an observable level. Experimental investigations of the validity of Lorentz symmetry therefore provide valuable tests of the framework of modern theoretical physics.Clock-comparison experiments [1-6] serve as sensitive probes of rotation invariance and hence of Lorentz symmetry, essentially by bounding the frequency variation of a clock as its orientation changes. In practice, the most precise limits are obtained by comparing the frequencies of two different co-located clocks as they rotate with the Earth. Typically, the clocks are electromagnetic signals emitted or absorbed on hyperfine or Zeeman transitions.Here, we report on a search for sidereal variations in the frequency of co-located 129 Xe and 3 He masers, both operating on nuclear spin-1͞2 Zeeman transitions. In the context of a general standard-model extension allowing for the possibility of Lorentz and CPT violation [7,8], the 129 Xe͞ 3 He-maser experiment sets the most stringent limit to date on leading-order Lorentz and CPT violation of the neutron: about 10 231 GeV, or more than 6 times better than the best previous measurements [9].The standard-model extension used to interpret this experiment emerges from any underlying theory that reduces at low energy to the standard model and contains spontaneous Lorentz violation [10]. For example, this might occur in string theory [11]. The standard-model extension maintains theoretically desirable properties of the usual standard model [8] [22,23]. A reanalysis by Adelberger, Gundlach, Heckel, and co-workers of existing data from a spin-polarized torsion-pendulum experiment [24,25] sets the most stringent bound to date on Lorentz and CPT violation of the electron, at about 10 228 GeV [26]. A recent Lorentzsymmetry test using hydrogen masers searched for hydrogen Zeeman-frequency sidereal variations, placing a bound on Lorentz violation at the level of 10 227 GeV [27]. Together with the results of Ref. [26], this implies an improved clean limit of 10 227 GeV on Lorentz-violating couplings involving the proton. Also, the KTeV experiment at Fermilab and the OPAL and DELPHI collaborations at CERN have constrained possible Lorentz-and CPT-violating effects in the K and B d systems [28,29].The design and operation of the two-species 129 Xe͞ 3 He maser has been discussed in r...

show abstract

Section: Limit On Lorentz and Cpt Violation Of The Neutron Using A Twmentioning

confidence: 99%

Limit on Lorentz andCPTViolation of the Neutron Using a Two-Species Noble-Gas Maser

et al. 2000

Self Cite

View full text Add to dashboard Cite

show abstract

“…The Lorentz-violating (LV) terms, generated as vacuum expectation values of tensors defined in a high energy scale, are coupled to the physical fields yielding coordinate invariance and violation of Lorentz symmetry in the particle frames [11]. This theoretical framework has inspired a large number of investigations in the last several years, encompassing fermion systems [12][13][14][15][16][17][18][19][20], CPT-probing experiments [21][22][23][24][25][26][27], the electromagnetic CPT-and Lorentzodd term [28]- [41], the CPT-even and Lorentz-odd gauge sector and its interactions with fermions [42][43][44][45][46][47][48][49][50][51], [52][53][54][55][56][57]. Recent investigations involving higher dimensional operators [58][59][60], its possible connections with LV theories [61][62][63][64][65][66], and nonminimal couplings …”

Section: Introductionmentioning

confidence: 99%

Einstein-Hilbert graviton modes modified by the Lorentz-violating bumblebee field

et al. 2014

View full text Add to dashboard Cite

In this work, we investigate the consequences of the spontaneous breaking of Lorentz symmetry, triggered by the bumblebee vector field, on the usual Einstein-Hilbert theory. Specifically, we consider the Einstein-Hilbert action modified by the bumblebee dynamic field, and evaluate the graviton propagator using an extended basis of Barnes-Rivers tensor projectors, involving the Lorentz-violating vector. Once the propagator is carried out, we proceed with discussing the consistency of the model, writing the dispersion relations, and analyzing causality and unitarity.We verify that this model possesses two dispersion relations: one provides causal and unitary propagating modes, while the second yields a causal but nonunitary mode which spoils the physical consistency of the model.

show abstract

“…The SME is a dynamical model constructed to contain all Lorentz-and CPT-violating lagrangian terms consistent with coordinate independence, which is a fundamental requirement to be discussed below. To date, numerous Lorentz-and CPT-violation tests involving hadrons [8][9][10][11][12][13][14][15][16][17][18][19][20][21], protons and neutrons [22][23][24][25][26][27][28][29][30][31], electrons [31][32][33][34][35][36][37][38][39][40][41], photons [42][43][44][45][46][47], muons [48][49][50], and neutrinos [2,[51][52][53][54] have been analysed or identified within th...…”

Section: Motivationmentioning

confidence: 99%

The Lorentz-Violating Extension of the Standard Model

Lehnert

2004

Beyond the Desert 2003

View full text Add to dashboard Cite

Abstract. Quantum-gravity effects are expected to be suppressed by the Planck mass. For experimental progress it is therefore important to identify potential signatures from Planck-scale physics that are amenable to ultrahigh-precision tests. It is argued that minuscule violations of Lorentz and CPT symmetry are candidate signals. In addition, theoretical and experimental aspects of the Standard-Model Extension, which describes the emergent low-energy effects, are discussed. MotivationAn important open question in our understanding of nature at its fundamental level concerns a unified quantum description of all fundamental interactions including gravity. Such a theory is likely to become dominant only as the Planck scale is approached, so that quantum-gravity effects are expected to be minuscule at presently attainable energies. Moreover, the absence of a fully realistic and viable candidate underlying theory provides a major obstacle for the identification of concrete quantum-gravity signatures that can be searched for in present-day or near-future experiments.A possible approach to overcome this phenomenological issue is to determine exact relations in the currently accepted laws of physics that may be violated in prospective fundamental theories and that can be tested with ultrahighprecision. Symmetries typically satisfy these criteria. For example, Lorentz and CPT invariance are cornerstones of our present understanding of nature at the fundamental level, and a variety of Lorentz and CPT tests belong to the most sensitive null experiments available. Lorentz and CPT violation is also a key feature of certain approaches to underlying physics.For example, couplings varying on cosmological scales are one possible source of Lorentz and CPT violation [1]. This fact does not come as a surprise: parameters dependent on spacetime break translational invariance, and translations, rotations, and boosts are linked in the Poincaré group. Thus, violations of translation symmetry can also affect Lorentz invariance. This can be understood intuitively as follows. The equations of motion typically contain the gradient of the coupling, which selects a preferred direction in spacetime leading to apparent Lorentz violation.In this talk, we discuss some theoretical and experimental aspects of the Standard-Model Extension (SME) [2][3][4][5][6][7], which is the low-energy framework for Lorentz-breaking effects. The SME is a dynamical model constructed to contain all Lorentz-and CPT-violating lagrangian terms consistent with coordinate

show abstract

CPTand Lorentz Tests with Muons

Cited by 249 publications

References 47 publications

Limit on Lorentz andCPTViolation of the Neutron Using a Two-Species Noble-Gas Maser

Limit on Lorentz andCPTViolation of the Neutron Using a Two-Species Noble-Gas Maser

Einstein-Hilbert graviton modes modified by the Lorentz-violating bumblebee field

The Lorentz-Violating Extension of the Standard Model

Contact Info

Product

Resources

About