Measurement of the τ lepton mass at the KEDR detector

Anashin, V.V.; Aulchenko, V.; Baldin, E. M.; Barladyan, A.K.; Barnyakov, A.; Barnyakov, M.Yu.; Baru, S.E.; Bedny, I.; Beloborodova, O.; Blinov, A. E.; Blinov, V.; Bobrov, A.; Bobrovnikov, Viktor; Bogomyagkov, A.; Bondar, A.; Bondarev, D.V.; Бузыкаев, А. Р.; Cherepanov, V. P.; Eidelman, S.; Glukhovchenko, Yu.M.; Gulevich, V.V.; Karnaev, S. E.; Karpov, G. V.; Karpov, S. V.; Киселев, В. А.; Kononov, S.A.; Kotov, K.; Kravchenko, E. A.; Kremyanskaya, E. V.; Kulikov, V.; Kurkin, G.Ya.; Купер, Э. А.; Levichev, E.; Maksimov, D.A.; Малышев, В. М.; Maslennikov, A. L.; Medvedko, A. S.; Meshkov, O.; Mishnev, S. E.; Морозов, И. И.; Muchnoi, N. Yu.; Neufeld, V. V.; Никитин, С. А.; Nikolaev, I. B.; Onuchin, A. P.; Oreshkin, S.B.; Орлов, И.; Осипов, А. А.; Peleganchuk, S. V.; Petrosyan, S. S.; Pivovarov, S.G.; Piminov, P.; Petrov, Vladimir; Poluektov, A.; Поспелов, Г. Е.; Prisekin, V.G.; Рубан, А.А.; Sandyrev, V. K.; Savinov, G.A.; Shamov, A.G.; Shatilov, D.; Shubin, E. I.; Shwartz, B.; Sidorov, V.; Симонов, Е. А.; Sinyatkin, S.; Skovpen, Yu. I.; Skrinsky, A.N.; Smaluk, Victor; Soukharev, A. M.; Struchalin, Maksim; Talyshev, A. A.; Tayursky, V.A.; Telnov, V. I.; Tikhonov, Yu. A.; Todyshev, K. Yu; Tumaikin, G.M.; Usov, Y.; Воробйов, А.І.; Yushkov, A. N.; Zhilich, V.; Журавлев, А. Н.

doi:10.1134/s0021364007080012

Cited by 44 publications

(20 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Calculated slopes and intercepts are tabulated in Tables (14,15,16). The estimated masses of the charmonium fit well to the (n, M 2 ) and (J, M 2 ) planes trajectories.…”

Section: Regge Trajectoriesmentioning

confidence: 77%

“…In parallel observation, W. Bacino and others at SLAC discovered and confirmed the ψ(3770) resonance with mass 3770±6 MeV [12] and the parameters were determined by SLAC and LBL collaborations [13]. In 2006 BES Collaboration measured the precise measurements of the mass of ψ(3770) resonance [14] and recently its parameters have been measured using the data collected with the KEDR detector [15]. The Belle collaboration reported the first observation of a new charmonium-like state with mass 3943 ± 6 ± 6 MeV in the spectrum of masses recoiling from the J/ψ in the inclusive process e + e − → J/ψ + anything, and denoted it as X(3940) [16].…”

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

Spectroscopy and decay properties of charmonium

Kher

Kumar

2018

Chinese Phys. C

View full text Add to dashboard Cite

The mass spectra of charmonium are investigated using a Coulomb plus linear (Cornell) potential. Gaussian wave function in position space as well as in momentum space are employed to calculate the expectation value of potential and kinetic energy respectively. Various experimental states (X(4660)(5 3 S1), X(3872)(2 3 P1), X(3900)(2 1 P1), X(3915)(2 3 P0) and X(4274)(3 3 P1) etc.) are assigned as charmonium states. We also study the Regge trajectories, pseudoscalar and vector decay constants, the Electric and Magnetic dipole transition rates and the annihilation decay width for charmonium states.

show abstract

“…Calculated slopes and intercepts are tabulated in Tables (14,15,16). The estimated masses of the charmonium fit well to the (n, M 2 ) and (J, M 2 ) planes trajectories.…”

Section: Regge Trajectoriesmentioning

confidence: 77%

Section: Introductionmentioning

confidence: 98%

Spectroscopy and decay properties of charmonium

Kher

Kumar

2018

Chinese Phys. C

View full text Add to dashboard Cite

show abstract

“…The result, B(ψ(2S) → τ + τ − ) = (3.08 ± 0.21 ± 0.38) × 10 −3 , has better relative preci- sion (14%) than previous measurements [505,506]. Using part of their statistics KEDR measured Γ(ψ(2S) → e + e − ) × B(ψ(2S) → τ + τ − ) to be 9.0 ± 2.6 eV [507], which, using the average from Table 29, implies a value B(ψ(2S) → τ + τ − ) = (3.8 ± 1.1) × 10 −3 , consistent with but considerably less precise than the result from BES.…”

Section: Two-photon Widths Of Charmoniamentioning

confidence: 87%

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

“…VEPP-4M will reach a maximum beam energy of E = 6 GeV and a luminosity of L = 10 31 /cm 2 /s. The main goal of the experiments at this facility are very high precision measurements of the -meson [475,476] and of the [477] and Υ families as well as two-photon physics using a dedicated zero-angle spectrometer for scattered electrons and positrons. The KEDR detector consists of a vertex detector, drift chamber, time of flight system of scintillation counters, a particle identification system based on aerogel Cherenkov counters, a calorimeter (with liquid krypton in the barrel part and CsI crystals in the end caps), and a muon tube system inside and outside of the magnet yoke.…”

Section: Experiments E760/e835 At Fnalmentioning

confidence: 99%

Glueballs, hybrids, multiquarks

2007

View full text Add to dashboard Cite

Glueballs, hybrids and multiquark states are predicted as bound states in models guided by quantum chromo dynamics (QCD), by QCD sum rules or QCD on a lattice. Estimates for the (scalar) glueball ground state are in the mass range from 1000 to 1800 MeV, followed by a tensor and a pseudoscalar glueball at higher mass. Experiments have reported evidence for an abundance of meson resonances with 0 −+ , 0 ++ and 2 ++ quantum numbers. In particular, the sector of scalar mesons is full of surprises starting from the elusive and mesons. The a 0 (980) and f 0 (980), discussed extensively in the literature, are reviewed with emphasis on their Janus-like appearance as KK molecules, tetraquark states or qq mesons. Most exciting is the possibility that the three mesons f 0 (1370), f 0 (1500), and f 0 (1710) might reflect the appearance of a scalar glueball in the world of quarkonia. However, the existence of f 0 (1370) is not beyond doubt and there is evidence that both f 0 (1500) and f 0 (1710) are flavour octet states, possibly in a tetraquark composition. We suggest a scheme in which the scalar glueball is dissolved into the wide background into which all scalar flavour-singlet mesons collapse.There is an abundance of meson resonances with the quantum numbers of the . Three states are reported below 1.5 GeV/c 2 whereas quark models expect only one, perhaps two. One of these states, (1440), was the prime glueball candidate for a long time. We show that (1440) is the first radial excitation of the meson.Hybrids may have exotic quantum numbers which are not accessible by qq mesons. There are several claims for J P C = 1 −+ exotics, some of them with properties as predicted from the flux tube model interpreting the quark-antiquark binding by a gluon string. The evidence for these states depends partly on the assumption that meson-meson interactions are dominated by s-channel resonances. Hybrids with non-exotic quantum numbers should appear as additional states. Light-quark mesons exhibit a spectrum of (squared) masses which are proportional to the sum of orbital angular momentum and radial quantum numbers. Two states do not fall under this classification. They are discussed as hybrid candidates.The concept of multiquark states has received revived interest due to new resonances in the spectrum of states with open and hidden charm. The new states are surprisingly narrow and their masses and their decay modes often do not agree with simple quark-model expectations.Lattice gauge theories have made strong claims that glueballs and hybrids should appear in the meson spectrum. However, the existence of a scalar glueball, at least with a reasonable width, is highly questionable. It is possible that hybrids will turn up in complex multibody final states even though so far, no convincing case has been made for them by experimental data. Lattice gauge theories fail to identify the nonet of scalar mesons. Thus, at the present status of approximations, lattice gauge theories seem not to provide a trustworthy guide into unknown territory ...

show abstract

Measurement of the τ lepton mass at the KEDR detector

Cited by 44 publications

References 10 publications

Spectroscopy and decay properties of charmonium

Spectroscopy and decay properties of charmonium

Heavy quarkonium: progress, puzzles, and opportunities

Glueballs, hybrids, multiquarks

Contact Info

Product

Resources

About