Symmetries, angular distributions in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>ψ</mml:mi></mml:mrow><mml:mrow><mml:mo>′</mml:mo></mml:mrow></mml:msup></mml:mrow><mml:mo>→</mml:mo><mml:mi>γ</mml:mi><mml:mi>χ</mml:mi><mml:mo>→</mml:mo><mml:mi>γ</mml:mi><mml:mi>γ</mml:mi><mml:mi>ψ</mml:mi></mml:math>, and the interpretation of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>χ</mml:mi><mml:mn /><mml:mo>(</

Karl, Gabriel; Meshkov, S.; Rosner, Jonathan L.

doi:10.1103/physrevd.13.1203

Cited by 80 publications

(48 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[4], and detailed discussions of various ways to extract the M2/E1 ratio were presented in Ref. [5]. Many of these methods involved the use of distributions in several decay angles.…”

mentioning

confidence: 99%

“…The deviations are of opposite signs for J = 1 and J = 2, and slightly larger for J = 2 as a result of the larger value of x J + x ′ J . We conclude with a discussion of the effect of an M2 admixture on the angle θ γ ′ P between the photon γ ′ in ψ(2S) → γχ c2 and the pseudoscalar meson P + in the decay χ c2 → P + P − , where, for example, P = π or K. This distribution is given in terms of z 1 ≡ cos θ γ ′ P and the helicity amplitudes B by [5] Figure 4: Distribution in cos θ ′ P , where θ γ ′ P is the angle between the photon γ ′ in ψ(2S) → γχ c2 and the pseudoscalar meson P + in the decay χ c2 → P + P − . Solid curve: pure E1; dashed curve: with expected M2 admixture corresponding to x ′ 2 = −0.021.…”

mentioning

confidence: 99%

“…Many observables are most simply expressed in terms of the As and Bs [5] We begin with the distributions with respect to the angles θ ′ and θ defined above. They are:…”

mentioning

confidence: 99%

“…The current state of experimental and theoretical information on M2 admixtures is summarized in Table I. Energies for the transitions ψ(2S) → γ ′ χ cJ and χ cJ → γJ/ψ are summarized in Table II. Helicity amplitudes A J |ν| for χ cJ → γJ/ψ decays and B J |ν| for ψ(2S) → γ ′ χ cJ are related to respective multipole amplitudes a J Jγ and b J J ′ γ [5] as…”

mentioning

confidence: 99%

“…We next discuss the effect of an M2 admixture on the photon-photon correlation angle θ γ ′ γ . Defining z c ≡ cos θ γ ′ γ , the distributions in terms of helicity amplitudes are [5]:…”

mentioning

confidence: 99%

See 4 more Smart Citations

M2 signatures inψ(2S)radiative decays

Rosner

2008

Phys. Rev. D

Self Cite

View full text Add to dashboard Cite

The sensitivity of observables in radiative decays ψ(2S) → γχ c1,2 → γγJ/ψ to quadrupole (M2) admixtures in the dominant electric dipole (E1) transitions is explored. Emphasis is placed on distributions in a single angle, and several examples are given.PACS numbers: 14.40. Gx, 13.20.Gd, 13.40.Hq, 12.39.Jh Radiative decays of charmonium (cc) states are expected to be dominated by electric dipole (E1) transitions, with higher multipoles suppressed by powers of photon energy divided by quark mass [1]. (An early discussion of charmonium radiative transitions may be found in Ref. [2].) The search for contributions of higher multipoles is of interest as a source of information on the charmed quark's magnetic moment, which is difficult to measure directly because of the extremely short lifetime of charmed hadrons. The possibility of anomalous magnetic moments of heavy quarks being larger than those of light ones, as a result of light-quark loops, was raised in Ref. [3].Expectations for the magnitude of magnetic quadrupole (M2) transitions in charmonium were calculated in Ref. [4], and detailed discussions of various ways to extract the M2/E1 ratio were presented in Ref. [5]. Many of these methods involved the use of distributions in several decay angles. The present note is devoted to several sources of information on the M2/E1 ratio based on distributions with respect to a single angle. These distributions can be examined in new data on ψ(2S) decays from the CLEO Detector at the Cornell Electron-Positron Storage Ring (CESR) [6].The distributions which will be examined are with respect to the following angles: (1) the angle θ ′ between the initial positron e + and the photon γ ′ in the ψ(2S) center-of-mass system (c.m.s.), where ψ(2S) → γ ′ χ c ; (2) the angle θ between the photon γ in χ c → γJ/ψ and the final ℓ + direction in J/ψ → ℓ + ℓ − , in the J/ψ c.m.s.; (3) the angle θ γ ′ γ between γ ′ and γ in the cascade ψ(2S) → γ ′ χ c → γ ′ γJ/ψ, evaluated in the χ c c.m.s., and (4) the angle θ γ ′ P in the cascade ψ(2S) → γ ′ χ c → γ ′ P + P − , where P = π or K, between γ ′ and P + , evaluated in the χ c c.m.s. In cases (1) through (3), one obtains information on the M2/E1 admixture from χ c1 and χ c2 , while in case (4) only χ c2 provides information, as χ c1 does not decay to P + P − . The transitions ψ(2S) → γ ′ χ c0 and χ c0 → γJ/ψ are purely electric dipole (E1) and do not provide information on the M2 amplitude.

show abstract

“…[4], and detailed discussions of various ways to extract the M2/E1 ratio were presented in Ref. [5]. Many of these methods involved the use of distributions in several decay angles.…”

mentioning

confidence: 99%

mentioning

confidence: 99%

“…Many observables are most simply expressed in terms of the As and Bs [5] We begin with the distributions with respect to the angles θ ′ and θ defined above. They are:…”

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations