Instability statistics and mixing rates

Artuso, Roberto; Manchein, Cesar

doi:10.1103/physreve.80.036210

Cited by 46 publications

(94 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The solid circles represent data from CLEO [450], which show consistency with predictions (dashed vertical lines), unlike some earlier measurements. The nonrelativistic theoretical expectations are calculated with an anomalous magnetic moment of the charm quark of zero and an assumed 1.5 GeV charm quark mass.…”

Section: Observation Of ψ(3770) → γχCj (1p )mentioning

confidence: 58%

“…The nonrelativistic theoretical expectations are calculated with an anomalous magnetic moment of the charm quark of zero and an assumed 1.5 GeV charm quark mass. Adapted from [450] with kind permission, copyright (2009) The American Physical Society monium state with a small admixture of 2 3 S 1 . However, because it predominantly decays to DD, its behavior as a state of charmonium has gone relatively unexplored in comparison to its lighter partners.…”

Section: Observation Of ψ(3770) → γχCj (1p )mentioning

confidence: 99%

“…Previous measurements of the relative sizes of the M2 amplitudes have disagreed with theoretical expectations. CLEO [450] has recently revisited this issue with a high-statistics analysis of the decay chains ψ(2S) → γχ cJ ; χ cJ → γJ/ψ; J/ψ → l + l − (l = e, µ) for J = 1, 2. Starting with 24 × 10 6 ψ(2S) decays, CLEO observes approximately 40 000 events for J = 1 and approximately 20 000 events for J = 2, significantly larger event samples than previous measurements.…”

Section: Higher-order Multipole Amplitudesmentioning

confidence: 99%

See 2 more Smart Citations

Heavy quarkonium: progress, puzzles, and opportunities

Brambilla¹,

Eidelman²,

Heltsley³

et al. 2011

Advances in the Physics of Particles and Nuclei

103

View full text Add to dashboard Cite

A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the B-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations at BESIII, the LHC, RHIC, FAIR, the Super Flavor and/or Tau-Charm factories, JLab, the ILC, and beyond. The list of newly-found conventional states expanded to include hc(1P ), χc2(2P ), B + c , and η b (1S). In addition, the unexpected and still-fascinating X(3872) has been joined by * Editors † Section coordinators ‡ Corresponding author: bkh2@cornell.edu more than a dozen other charmonium-and bottomonium-like "XY Z" states that appear to lie outside the quark model. Many of these still need experimental confirmation. The plethora of new states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of cc, bb, and bc bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. Lattice QCD has grown from a tool with computational possibilities to an industrialstrength effort now dependent more on insight and innovation than pure computational power. New effective field theories for the description of quarkonium in different regimes have been developed and brought to a high degree of sophistication, thus enabling precise and solid theoretical predictions. Many expected decays and transitions have either been measured with precision or for the first time, but the confusing patterns of decays, both above and below open-flavor thresholds, endure and have deepened. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hotand cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.

show abstract

Section: Observation Of ψ(3770) → γχCj (1p )mentioning

confidence: 58%

Section: Observation Of ψ(3770) → γχCj (1p )mentioning

confidence: 99%

Section: Higher-order Multipole Amplitudesmentioning

confidence: 99%

See 1 more Smart Citation

Heavy quarkonium: progress, puzzles, and opportunities

Brambilla¹,

Eidelman²,

Heltsley³

et al. 2011

Advances in the Physics of Particles and Nuclei

103

View full text Add to dashboard Cite

show abstract

“…The ratio of the M2 contributions of ψð3686Þ → γ 1 χ c1 to ψð3686Þ → γ 1 χ c2 (χ c1 → γ 2 J=ψ to χ c2 → γ 2 J=ψ) is independent of the m c and κ of the charm quark to first order in E γ =m c and predicted to be b [5], where the dominant uncertainties come from ignoring contributions of higher order in ðE γ =m c Þ 2 . Higher-order multipole amplitudes can be obtained by investigating the angular distributions of the final-state particles [1,6,7].…”

Section: Introductionmentioning

confidence: 99%

“…Using the same method as reported in Refs. [5,11,12], the joint angular distributions W χ cJ can be expressed in terms of a …”

mentioning

confidence: 99%

Measurement of higher-order multipole amplitudes in ψ(3686)→γχc1,2 with
Ablikim¹,
Ачасов²,
Ai³
et al. 2017
Phys. Rev. D

View full text Add to dashboard Cite

Measurement of higher-order multipole amplitudes in ψð3686Þ → γχ c1;2 with χ c1;2 → γJ=ψ and search for the transition η c ð2SÞ → γJ=ψ Using 106 ×10 6 ψð3686Þ events collected with the BESIII detector, we measure multipole amplitudes for the decay ψð3686Þ → γχ c1;2 → γγJ=ψ beyond the dominant electric-dipole amplitudes. The normalized magnetic-quadrupole (M2) amplitude for ψð3686Þ → γχ c1;2 → γγJ=ψ and the normalized electricoctupole amplitudes for ψð3686Þ → γχ c2 , χ c2 → γJ=ψ are determined. The M2 amplitudes for ψð3686Þ → γχ c1 and χ c1;2 → γJ=ψ are found to differ significantly from zero and are consistent with theoretical predictions. We also obtain the ratios of M2 contributions of ψð3686Þ and J=ψ decays to χ c1;2 , b By considering the multipole contributions of χ c1;2 , we measure the product branching fractions for the cascade decays ψð3686Þ → γχ c0;1;2 → γγJ=ψ and search for the process η c ð2SÞ → γJ=ψ through ψð3686Þ → γη c ð2SÞ. The product branching fraction for ψð3686Þ → γχ c0 → γγJ=ψ is 3σ larger than published measurements, while those of ψð3686Þ → γχ c1;2 → γγJ=ψ are consistent. No significant signal for the decay ψð3686Þ → γη c ð2SÞ → γγJ=ψ is observed, and the upper limit of the product branching fraction at the 90% confidence level is determined. I. INTRODUCTIONThe processes ψð3686Þ → γ 1 χ c1;2 and χ c1;2 → γ 2 J=ψ are dominated by electric-dipole (E1) amplitudes but allow for higher multipole amplitudes as well, such as the magneticquadrupole (M2) and electric-octupole (E3) transitions. The contributions of these higher multipole amplitudes give information on the anomalous magnetic moment κ of the charm quark [1,2] and on the admixture of S-and D-wave states [3]. The normalized M2 contributions for ψð3686Þ → γ 1 χ c1;2 and χ c1;2 → γ 2 J=ψ, which are referred to as b 2 , corrected to first order in E γ 1;2 =m c , where E γ 1;2 is the energy of γ 1;2 in the rest frame of the mother charmonium state, are predicted [4] to berespectively. The ratio of the M2 contributions of ψð3686Þ → γ 1 χ c1 to ψð3686Þ → γ 1 χ c2 (χ c1 → γ 2 J=ψ to χ c2 → γ 2 J=ψ) is independent of the m c and κ of the charm quark to first order in E γ =m c and predicted to be b In this paper, we report on a measurement of the higherorder multipole amplitudes in the processes of ψð3686Þ → γ 1 χ c1;2 ; χ c1;2 → γ 2 J=ψ, where the J=ψ is reconstructed in its decay modes J=ψ →l þ l − ðl¼e=μÞ. The measurements make use of the joint distributions of the five helicity angles in the final state. Using the invariant mass of γ 2 J=ψ, we obtain the product branching fractions of ψð3686Þ → γ 1 χ c0;1;2 → γ 1 γ 2 J=ψ and search for η c ð2SÞ → γ 2 J=ψ produced through ψð3686Þ → γ 1 η c ð2SÞ. In the measurement of the product branching fractions of ψð3686Þ → γ 1 χ c0;1;2 → γ 1 γ 2 J=ψ, the multipole contributions of χ c1;2 are considered for the first time. The results presented in this manuscript supersede the ones in Ref. [18]. The analyses are based on a sample of 156 pb −1 taken at a center-of-mass energy 3.686 GeV, corresponding to ...

show abstract