Two-photon helicity selection rules and widths for positronium and quarkonium states with arbitrary angular momenta

Ackleh, E.S.; Barnes, T.; Close, F.E.

doi:10.1103/physrevd.46.2257

Cited by 11 publications

(13 citation statements)

References 21 publications

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“…Relations similar to equation (48) exist for the higher multiplets, and enable, for example, separation of the 2 ++ radial excitation of the 3 P2(1270), expected at ~1800 MeV, from the 3 F2 state expected to lie in the same mass region [155]. The The general conclusion from this particular example is that the γγ process provides powerful information on both the flavour and the spin/angular-momentum internal structure ofhadrons.…”

mentioning

confidence: 70%

A full-acceptance detector at the LHC (FELIX)

Ageev¹,

Akhobadze²,

Alvero³

et al. 2002

J. Phys. G: Nucl. Part. Phys.

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The FELIX collaboration had proposed the construction of a full-acceptance detector for the LHC. The primary mission of FELIX was the study of QCD: to provide comprehensive and definitive observations of a very broad range of strong-interaction processes. This document contains an extensive discussion of this physics menu. In a further paper the FELIX detector will be reviewed. Contents HISTORYWith the advent of the large hadron collider (LHC), we are on the threshold of a new era in high-energy physics. With instrumentation in the form of dedicated experiments of unprecedented precision and complexity, the LHC will move significantly beyond the current high-energy frontier, and dramatically improve our understanding of particle physics at the highest energies and shortest distances accessible to man.As currently planned, however, the LHC experimental programme is incomplete. Moreover, these deficiencies continue and extend what has been a gap in the experimental programme of all hadron colliders. The problem lies in the design of the detectors instrumenting hadron colliders: they are all optimized for rare, high-pt events. These 'general purpose' detectors are anything but that. Rather, they are designed to explore extreme shortdistance phenomena. Without intending to demean the efforts of the collaborations which have built or are building these detectors, it is nevertheless these events in which the theorists are most confident that they understand the physics, and are in many ways experimentally most accessible.While there is no doubt that such physics and such detectors should be the centrepiece of any programme of hadron collider physics, it seems much less clear that they should be the only item on the agenda. Indeed, it can be argued that a full-acceptance detector, capable of detecting and measuring each particle in an event well, may have the greatest discovery potential. Alas, the absence of any experimental effort in this direction in the collider era has meant that both theoretical investigations and experimental design of such detectors has languished, to the point that many in the community have come to think of high-pt physics as the last frontier in particle physics.The FELIX collaboration sought to rectify this situation. With support from the CERN administration, some 160 physicists collaborated in preparing the FELIX LoI. Many of these could not officially join the collaboration, and so their help could only be acknowledged. While the FELIX proposal was never officially killed, it was nevertheless effectively killed without the collaboration making a formal presentation to the LHC committee.All of this, of course, is history, and not very pleasant history at that. The motivation for a full-acceptance detector remains, however, and interest on the part of the broader community, despite the implications of this history, remains high. Because of this, the FELIX collaboration, together with those who helped but were not members, believes that it is important to document the physics of a ...

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mentioning

confidence: 70%

A full-acceptance detector at the LHC (FELIX)

Ageev¹,

Akhobadze²,

Alvero³

et al. 2002

J. Phys. G: Nucl. Part. Phys.

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“…For example, the vector mesons are produced in e + e − collisions through their couplings to e + e − . Annihilation decay rates have been studied extensively using perturbative QCD (pQCD) methods [40,[46][47][48][49][50][51][52][53][54][55][56][57][58]. The relevant formulas for S-and P -wave states including first-order QCD corrections (when they are known) are summarized in Ref.…”

Section: Bottomonium Mass Spectrummentioning

confidence: 99%

“…[55,56] and Refs. [54,57] respectively. The expression for 3 D 1 → e + e − including the QCD correction comes from Ref.…”

Section: Bottomonium Mass Spectrummentioning

confidence: 99%

Bottomonium mesons and strategies for their observation

2015

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The B-factories and Large Hadron Collider experiments have demonstrated the ability to observe and measure the properties of bottomonium mesons. In order to discover missing states it is useful to know their properties to develop a successful search strategy. To this end we calculate the masses and decay properties of excited bottomonium states. We use the relativized quark model to calculate the masses and wavefunctions and the 3 P0 quark-pair creation model to calculate decay widths to open bottom. We also summarize results for radiative transitions, annihilation decays, hadronic transitions and production cross sections which are used to develop strategies to find these states. We find that the bb system has a rich spectroscopy that we expect to be substantially extended by the LHC and e + e − experiments in the near future. Some of the most promising possibilities at the LHC are observing the χ b(1,2) (3P ), χ b(1,2) (4P ) and η b (3S

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“…This is a difficult condition to satisfy in the case of QCD where α → α s ∼ 1. Nevertheless, this approach has been adopted to inclusive strong decays of mesons [17,18,19] and has been extensively applied to two-photon decays of quarkonia [20].…”

Section: A Formalism and Motivationmentioning

confidence: 99%

Dynamic properties of charmonium

2006

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Nonrelativistic quark models of charmonia are tested by comparison of theoretical charmonium decay constants, form factors, and γγ widths with experiment and lattice gauge computations. The importance of relativistic effects, a running coupling, and the correct implementation of bound state effects are demonstrated. We describe how an improved model and computational techniques resolve several outstanding issues in previous nonrelativistic quark models such as the use of 'correction' factors in quark model form factors, artificial energy prescriptions in decay constant calculations, and ad hoc phase space modifications. We comment on the small experimental value of f ψ ′′ and the D-wave component of the J/ψ. Decay constants and γγ widths for bottomonium are also presented.

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Two-photon helicity selection rules and widths for positronium and quarkonium states with arbitrary angular momenta

Cited by 11 publications

References 21 publications

A full-acceptance detector at the LHC (FELIX)

A full-acceptance detector at the LHC (FELIX)

Bottomonium mesons and strategies for their observation

Dynamic properties of charmonium

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