Formation of the ηc in two-photon collisions at LEP

Acciarri, M.; Achard, P.; Adriani, O.; Aguilar-Benı́tez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M. G.; Ambrosi, G.; Anderhub, H.; Andreev, V.; Angelescu, T.; Anselmo, F.; Arefiev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Baksay, L.; Balandras, A.; Ball, R. C.; Banerjee, S.; Barczyk, A.; Barillère, R.; Barone, L.; Bartalini, P.; Basile, M.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B. L.; Bhattacharya, S.; Biasini, M.; Biland, A.; Blaising, J. J.; Blyth, S.; Bobbink, G. J.; Böhm, A.; Boldizsár, L.; Borgia, B.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J. G.; Brigljević, V.; Brochu, F. M.; Buffini, A.; Buijs, A.; Burger, J. D.; Burger, W. J.; Busenitz, J.; Button, A.; Cai, X. D.; Campanelli, M.; Capell, M.; Romeo, G. Cara; Carlino, G.; Cartacci, A. M.; Casaus, J.; Castellini, G.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Cesaroni, F.; Chamizo, M.; Chang, Y. H.; Chaturvedi, U. K.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G. M.; Chen, H. F.; Chen, H. S.; Chéreau, X.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Civinini, C.; Clare, I.; Clare, R.; Coignet, G.; Colijn, A. P.; Colino, N.; Costantini, S.; Cotorobai, F.; Cozzoni, B.; Cruz, B. De La; Csilling, Á.; Cucciarelli, S.; Dai, T.; Dalen, J. A. van; D’Alessandro, R.; Asmundis, R. de; Déglon, P.; Degré, A.; Deiters, K.; Volpe, D. della; Denes, P.; DeNotaristefani, F.; Salvo, A. De; Diemoz, M.; Dierendonck, D. van; Lodovico, F. Di; Dionisi, C.; Dittmar, M.; Dominguez, A.; Doria, A.; Dova, M. T.; Duchesneau, D.; Dufournand, D.; Duinker, P.; Durán, I.; Mamouni, H. El; Engler, A.; Eppling, F. J.; Erné, F.C.; Extermann, P.; Fabre, Michel; Faccini, R.; Falagán, M. A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O. L.; Felcini, M.; Ferguson, T.; Ferroni, F.; Fesefeldt, H.; Fiandrini, E.; Field, J. H.; Filthaut, F.; Fisher, P. H.; Fisk, I.; Forconì, G.; Fredj, L.; Freudenreich, K.; Furetta, C.; Galaktionov, Yu.; Ganguli, S. N.; Garcı́a-Abia, P.; Gataullin, M.; Gau, S. S.; Gentile, S.; Gheordanescu, N.; Giagu, S.; Gong, Z. F.; Grenier, G.; Grimm, O.; Gruenewald, M. W.; Gulik, R. van; Gupta, Virendra K.; Gurtu, A.; Gutay, L.; Haas, D.; Hasan, A.; Hatzifotiadou, D.; Hebbeker, T.; Hervé, A.; Hidas, P.; Hirschfelder, J.; Hofer, H.; Holzner, G.; Hoorani, H. R.; Hou, S.; Iashvili, I.; Jin, B. N.; Jones, L. W.; Jong, P. de; Josa-Mutuberrı́a, I.; Khan, R. A.; Kamrad, D.; Kaur, M.; Kienzle‐Focacci, M. N.; Kim, D.; Kim, D. H.; Kim, J. K.; Kim, S. C.; Kirkby, J.; Kiss, D.; Kittel, W.; Klimentov, A.; König, A. C.; Kopp, A. K.; Korolko, I.; Koutsenko, V.; Kräber, M.; Kraemer, R. W.; Krenz, W.; Kunin, A.; Lacenter, P.; Guevara, P. Ladrón de; Laktineh, Imad Baptiste; Landi, G.; Lassila-Perini, K.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Coultre, P. Le; Lee, H. J.; Goff, J. M. Le; Leiste, R.; Leonardi, Emanuele; Levtchenko, P.; Li, C.; Lin, C. H.; Lin, W.; Linde, F.; Lista, L.; Liu, Z. A.; Lohmann, W.; Longo, E.; Lu, Y. S.; Lübelsmeyer, K.; Luci, C.; Luckey, D.; Lugnier, L.; Luminari, L.; Lustermann, W.; G., W.; Maity, M.; Malgeri, L.; Малинин, А.; Mañá, C.; Mangeol, D.; Marchesini, P.; Marian, G.; Martin, J. P.; Marzano, F.; Massaro, G.; Mazumdar, K.; McNeil, R. R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W. J.; Mey, M. von der; Mirabelli, G.; Mnich, J.; Mohanty, G. B.; Molnár, Péter; Monteleoni, B.; Moulik, T.; Muanza, G. S.; Muheim, F.; Muijs, A. J.M.; Napolitano, M.; Nessi‐Tedaldi, F.; Newman, H. B.; Nießen, T.; Nisati, A.; Nowak, H.; Oh, Y. D.; Organtini, G.; Ostonen, R.; Palomares, C.; Pandoulas, D.; Paoletti, S.; Paolucci, P.; Park, H. K.; Park, I. H.; Pascale, Gennaro De; Passaleva, G.; Patricelli, S.; Paul, T.; Pauluzzi, M.; Paus, C.; Pauß, F.; Peach, D.; Pedace, M.; Pei, Y. J.; Pensotti, S.; Perret-Gallix, D.; Petersen, B. A.; Piccolo, D.; Pieri, M.; Piroué, P.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Postema, H.; Pothier, J.; Produit, N.; Prokofiev, D.; Quartieri, J.; Rahal-Callot, G.; Rahaman, M. A.; Raja, N.; Ramelli, R.; Rancoita, P.G.; Raven, G.; Razis, P. A.; Ren, D.; Rescigno, M.; Reucroft, S.; Rhee, T. van; Riemann, S.; Riles, K.; Robohm, A.; Rodin, J.; Roe, B. P.; Romero, L.; Rosca, A.; Rosier‐Lees, S.; Rubio, J. A.; Ruschmeier, D.; Rykaczewski, H.; Sarkar, S.; Salicio, J.; Sánchez, E.; Sanders, M. P.; Sarakinos, M. E.; Schäfer, C.; Schegelsky, V. A.; Schmidt-Kaerst, S.; Schmitz, D.; Schopper, H.; Schotanus, D. J.; Schwenke, J.; Schwering, G.; Sciacca, C.; Sciarrino, D.; Seganti, A.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Siedenburg, T.; Son, D.; Smith, Bryan; Спиллантини, П.; Steuer, M.; Stickland, D.; Stone, A.; Stone, Howard A.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L. Z.; Suter, H.; Swain, J. D.; Szillási, Z.; Tang, X. W.; Tauscher, L.; Taylor, L.; Timmermans, C.; Ting, Samuel C.C.; Ting, S. M.; Tonwar, S. C.; Töth, J.; Tully, C.; Tung, K. L.; Uchida, Y.; Ulbricht, J.; Valente, E.; Vesztergombi, G.; Vetlitsky, I.; Vicinanza, D.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobiev, I.; Vorobyov, A. A.; Vorvolakos, A.; Wadhwa, M.; Wallraff, W.; Wang, M.; Wang, X. L.; Wang, Z. M.; Weber, A.; Weber, M.; Wienemann, P.; Wilkens, H. G.; Wu, S. X.; Wynhoff, S.; Xia, L.; Xu, Z. Z.; Yang, B. Z.; Yang, C. G.; Yang, H. J.; Yang, Min; Ye, J. B.; Yeh, S. C.; You, J. M.; Zalite, A.; Zalite, Y.; Zhang, Z. P.; Zhu, G. Y.; Zhu, R. Y.; Zichichi, A.; Ziegler, F.; Zilizi, G.; Zöller, Margot

doi:10.1016/s0370-2693(99)00784-4

Cited by 24 publications

(3 citation statements)

References 15 publications

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“…Surrounding the 10 cm diameter beam pipe, a high-precision silicon microstrip detector and a small drift chamber operating in the time expansion mode acted as charged particle vertex detectors, providing momentum resolution (p t )/p t = 0.021 · p t (p t in GeV/c). Results on meson spectroscopy can be found in [707][708][709][710][711][712][713][714][715][716][717][718][719].…”

Section: The L3 Experimentsmentioning

confidence: 99%

Glueballs, hybrids, multiquarks

2007

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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 ...

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Section: The L3 Experimentsmentioning

confidence: 99%

Glueballs, hybrids, multiquarks

2007

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“…γγ → η c , χ c0 , χ c2 . Charmomium production was studied by CLEO [340,341] and L3 [342]. The γγ and total widths of these states were measured.…”

Section: Experiments At E + E − -Collidersmentioning

confidence: 99%

Coherent γγ and γA interactions in very peripheral collisions at relativistic ion colliders

et al. 2002

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Due to coherence, there are strong electromagnetic fields of short duration in very peripheral collisions. They give rise to photon-photon and photon-nucleus collisions with a high flux up to an invariant mass region hitherto unexplored experimentally. After a general survey of the field equivalent photon numbers and photon-photon luminosities, especially for relativistic heavy ion collisions, are discussed. Special care needs to be taken to include the effects of the strong interaction and nuclear size in this case. Photon-photon and photon-hadron physics at various invariant mass scales are then discussed. The maximum equivalent photon energy in the lab-system (collider frame) are typically of the order of 3 GeV for RHIC and 100 GeV for LHC. Diffractive processes are an important background process. Lepton-pair, especially electron-positron pair production is copious. Due to the strong fields there will be new phenomena, like multiple e + e − pair production. The experimental techniques to select γγ-processes are finally discussed together with important background processes.

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“…The measurements on this form factor have been done by both L3 [8] and BaBar [9] Collaborations based on the process of e + e − → e + e − γ * γ * → e + e − η c in the range of Q 2 from 2 to 50 GeV 2 . Since η c is composed of two massive charm quarks, it is important to know the behavior of the η c → γ * γ transition form factor at a high Q 2 momentum transfer to examine the validity of the pQCD calculations in this heavy meson as well as compare with those of the light pseudoscalars.…”

Section: Introductionmentioning

confidence: 99%

Form factors of η c in light-front quark model

Geng

Lih

2013

Eur. Phys. J. C

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We study the form factors of the η c meson in the light-front quark model. We explicitly show that the transition form factor of η c → γ * γ as a function of the momentum transfer is consistent with the experimental data by the BaBar collaboration, while the decay constant of η c is found to be f ηc = 230.5 +52.2 −61.0 and 303.6 +115.2 −116.4 MeV for η c ∼ cc by using two η c → γγ decay widths of 5.3 ± 0.5 and 7.2 ± 2.1 keV, given by Particle Data Group and Lattice QCD calculation, respectively.

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Formation of the ηc in two-photon collisions at LEP

Cited by 24 publications

References 15 publications

Glueballs, hybrids, multiquarks

Glueballs, hybrids, multiquarks

Coherent γγ and γA interactions in very peripheral collisions at relativistic ion colliders

Form factors of η c in light-front quark model

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