Related papers: Prospects for detecting an $\eta_c'$ in two photon…

Line shape and the experimental determination of the $J/\psi \to \gamma\eta_c$ branching fraction

We study the photon spectrum line-shape of the $J/\psi \to \gamma\eta_c\to \gamma X$ decay process in a nonrelativistic effective field theory (EFT) framework of quantum chromodynamics (QCD). We take into account the finite width of the…

High Energy Physics - Phenomenology · Physics 2021-11-19 Jorge Segovia , Jaume Tarrús Castellà

Photoproduction of eta meson within a coupled-channels K-matrix approach

We investigate photoproduction of eta mesons off protons and neutrons within a coupled-channels effective-Lagrangian method which is based on the K-matrix approach. The two-body final channels included are pi-N, eta-N, phi-N, rho-N,…

Nuclear Theory · Physics 2009-09-09 R. Shyam , O. Scholten

Measurements of e+e- -> K+K-eta, K+K-pi0 and KsK+pi- Cross Sections Using Initial State Radiation Events

This paper reports measurements of processes: e+e- -> gamma KsK+pi-, e+e- -> gamma K+K-pi0, e+e- -> gamma phi eta, and e+e- -> gamma phi pi0. The initial state radiated photon allows to cover the hadronic final state in the energy range…

High Energy Physics - Experiment · Physics 2010-04-12 BaBar Collaboration , B. Aubert

Rare Decays of the $\eta^{'}$

We have searched for the rare decays of the eta prime meson to e+ e- eta, e+ e- pizero, e+ e- gamma, and e mu in hadronic events at the CLEO II detector. The search is conducted on 4.80 fb^-1 of e+ e- collisions at the Cornell Electron…

High Energy Physics - Experiment · Physics 2019-08-18 R. A. Briere

Creation and decay of eta-mesic nuclei

First experimental results on photoproduction of eta-mesic nuclei are analyzed. In an experiment performed at the 1 GeV electron synchrotron of the Lebedev Physical Institute, correlated pi+n pairs arising from the reaction gamma + 12C -> N…

Nuclear Experiment · Physics 2009-10-31 G. A. Sokol , T. A. Aibergenov , A. V. Koltsov , A. V. Kravtsov , Yu. I. Krutov , A. I. L'vov , L. N. Pavlyuchenko , V. P. Pavlyuchenko , S. S. Sidorin

eta-prime photoproduction on the proton for photon energies from 1.527 to 2.227 GeV

Differential cross sections for the reaction gamma p -> eta-prime p have been measured with the CLAS spectrometer and a tagged photon beam with energies from 1.527 to 2.227 GeV. The results reported here possess much greater accuracy than…

Nuclear Experiment · Physics 2010-04-06 M. Dugger , J. P. Ball , P. Collins , E. Pasyuk , B. G. Ritchie

Observing true tauonium via two-photon fusion at $e^+e^-$ and hadron colliders

The feasibility of observing true tauonium, the bound state of two tau leptons, $\mathcal{T}_0\equiv(\tau^+\tau^-)_0$, via photon-photon collisions at $e^+e^-$ colliders and at the LHC, is studied. The production cross sections of the…

High Energy Physics - Phenomenology · Physics 2022-05-25 David d'Enterria , Hua-Sheng Shao

E835 at FNAL: Charmonium Spectroscopy in $\bar p p$ Annihilations

I present preliminary results on the search for $h_c$ in its $\eta_c\gamma$ and $J/\psi\pi^0$ decay modes. We observe an excess of \eta_c\gamma$ events near 3526 MeV that has a probability ${\cal P} \sim 0.001$ to arise from background…

High Energy Physics - Experiment · Physics 2009-11-10 Claudia Patrignani

Measurements of the branching fractions of $\eta_c\to K^+K^-\pi^0$, $K^0_S K^{\pm}\pi^{\mp}$,$2(\pi^+\pi^-\pi^0)$, and $p \bar{p}$

Using data samples collected with the BESIII detector at center-of-mass energies $\sqrt{s} = 4.23, 4.26, 4.36,$ and $4.42$~\rm{GeV}, we measure the branching fractions of $\eta_c\to K^+K^-\pi^0$, $K^0_S K^{\pm}\pi^{\mp}$,…

High Energy Physics - Experiment · Physics 2019-08-07 M. Ablikim , M. N. Achasov , S. Ahmed , M. Albrecht , M. Alekseev , A. Amoroso , F. F. An , Q. An , Y. Bai , O. Bakina , R. Baldini Ferroli , Y. Ban , K. Begzsuren , D. W. Bennett , J. V. Bennett , N. Berger , M. Bertani , D. Bettoni , F. Bianchi , J. Bloms , I. Boyko , R. A. Briere , H. Cai , X. Cai , A. Calcaterra , G. F. Cao , S. A. Cetin , J. Chai , J. F. Chang , W. L. Chang , G. Chelkov , G. Chen , H. S. Chen , J. C. Chen , M. L. Chen , S. J. Chen , Y. B. Chen , W. Cheng , G. Cibinetto , F. Cossio , H. L. Dai , J. P. Dai , A. Dbeyssi , D. Dedovich , Z. Y. Deng , A. Denig , I. Denysenko , M. Destefanis , F. De Mori , Y. Ding , C. Dong , J. Dong , L. Y. Dong , M. Y. Dong , Z. L. Dou , S. X. Du , J. Z. Fan , J. Fang , S. S. Fang , Y. Fang , R. Farinelli , L. Fava , F. Feldbauer , G. Felici , C. Q. Feng , M. Fritsch , C. D. Fu , Y. Fu , Q. Gao , X. L. Gao , Y. Gao , Y. G. Gao , Z. Gao , B. Garillon , I. Garzia , A. Gilman , K. Goetzen , L. Gong , W. X. Gong , W. Gradl , M. Greco , L. M. Gu , M. H. Gu , Y. T. Gu , A. Q. Guo , L. B. Guo , R. P. Guo , Y. P. Guo , A. Guskov , S. Han , X. Q. Hao , F. A. Harris , K. L. He , F. H. Heinsius , T. Held , Y. K. Heng , Z. L. Hou , H. M. Hu , J. F. Hu , T. Hu , Y. Hu , G. S. Huang , J. S. Huang , X. T. Huang , X. Z. Huang , Z. L. Huang , T. Hussain , N. Hüsken , W. Ikegami Andersson , W. Imoehl , M. Irshad , Q. Ji , Q. P. Ji , X. B. Ji , X. L. Ji , H. L. Jiang , X. S. Jiang , X. Y. Jiang , J. B. Jiao , Z. Jiao , D. P. Jin , S. Jin , Y. Jin , T. Johansson , N. Kalantar-Nayestanaki , X. S. Kang , M. Kavatsyuk , B. C. Ke , I. K. Keshk , A. Khoukaz , P. Kiese , R. Kiuchi , R. Kliemt , L. Koch , O. B. Kolcu , B. Kopf , M. Kuemmel , M. Kuessner , A. Kupsc , M. Kurth , W. Kühn , J. S. Lange , P. Larin , L. Lavezzi , H. Leithoff , C. Li , Cheng Li , D. M. Li , F. Li , F. Y. Li , G. Li , H. B. Li , H. J. Li , J. C. Li , J. W. Li , Ke Li , L. K. Li , Lei Li , P. L. Li , P. R. Li , Q. Y. Li , W. D. Li , W. G. Li , X. L. Li , X. N. Li , X. Q. Li , X. H. Li , Z. B. Li , H. Liang , Y. F. Liang , Y. T. Liang , G. R. Liao , L. Z. Liao , J. Libby , C. X. Lin , D. X. Lin , B. Liu , B. J. Liu , C. X. Liu , D. Liu , D. Y. Liu , F. H. Liu , Fang Liu , Feng Liu , H. B. Liu , H. L Liu , H. M. Liu , Huanhuan Liu , Huihui Liu , J. B. Liu , J. Y. Liu , K. Y. Liu , Ke Liu , Q. Liu , S. B. Liu , X. Liu , Y. B. Liu , Z. A. Liu , Zhiqing Liu , Y. F. Long , X. C. Lou , H. J. Lu , J. D. Lu , J. G. Lu , Y. Lu , Y. P. Lu , C. L. Luo , M. X. Luo , P. W. Luo , T. Luo , X. L. Luo , S. Lusso , X. R. Lyu , F. C. Ma , H. L. Ma , L. L. Ma , M. M. Ma , Q. M. Ma , X. N. Ma , X. X. Ma , X. Y. Ma , Y. M. Ma , F. E. Maas , M. Maggiora , S. Maldaner , Q. A. Malik , A. Mangoni , Y. J. Mao , Z. P. Mao , S. Marcello , Z. X. Meng , J. G. Messchendorp , G. Mezzadri , J. Min , T. J. Min , R. E. Mitchell , X. H. Mo , Y. J. Mo , C. Morales Morales , N. Yu. Muchnoi , H. Muramatsu , A. Mustafa , S. Nakhoul , Y. Nefedov , F. Nerling , I. B. Nikolaev , Z. Ning , S. Nisar , S. L. Niu , S. L. Olsen , Q. Ouyang , S. Pacetti , Y. Pan , M. Papenbrock , P. Patteri , M. Pelizaeus , H. P. Peng , K. Peters , J. Pettersson , J. L. Ping , R. G. Ping , A. Pitka , R. Poling , V. Prasad , M. Qi , T. Y. Qi , S. Qian , C. F. Qiao , N. Qin , X. S. Qin , Z. H. Qin , J. F. Qiu , S. Q. Qu , K. H. Rashid , C. F. Redmer , M. Richter , M. Ripka , A. Rivetti , M. Rolo , G. Rong , Ch. Rosner , M. Rump , A. Sarantsev , M. Savrié , K. Schoenning , W. Shan , X. Y. Shan , M. Shao , C. P. Shen , P. X. Shen , X. Y. Shen , H. Y. Sheng , X. Shi , X. D Shi , J. J. Song , Q. Q. Song , X. Y. Song , S. Sosio , C. Sowa , S. Spataro , F. F. Sui , G. X. Sun , J. F. Sun , L. Sun , S. S. Sun , X. H. Sun , Y. J. Sun , Y. K Sun , Y. Z. Sun , Z. J. Sun , Z. T. Sun , Y. T Tan , C. J. Tang , G. Y. Tang , X. Tang , B. Tsednee , I. Uman , B. Wang , B. L. Wang , C. W. Wang , D. Y. Wang , H. H. Wang , K. Wang , L. L. Wang , L. S. Wang , M. Wang , Meng Wang , P. Wang , P. L. Wang , R. M. Wang , W. P. Wang , X. Wang , X. F. Wang , Y. Wang , Y. F. Wang , Z. Wang , Z. G. Wang , Z. Y. Wang , Zongyuan Wang , T. Weber , D. H. Wei , P. Weidenkaff , S. P. Wen , U. Wiedner , M. Wolke , L. H. Wu , L. J. Wu , Z. Wu , L. Xia , Y. Xia , Y. J. Xiao , Z. J. Xiao , Y. G. Xie , Y. H. Xie , X. A. Xiong , Q. L. Xiu , G. F. Xu , L. Xu , Q. J. Xu , W. Xu , X. P. Xu , F. Yan , L. Yan , W. B. Yan , W. C. Yan , Y. H. Yan , H. J. Yang , H. X. Yang , L. Yang , R. X. Yang , S. L. Yang , Y. H. Yang , Y. X. Yang , Yifan Yang , Z. Q. Yang , M. Ye , M. H. Ye , J. H. Yin , Z. Y. You , B. X. Yu , C. X. Yu , J. S. Yu , C. Z. Yuan , Y. Yuan , A. Yuncu , A. A. Zafar , Y. Zeng , B. X. Zhang , B. Y. Zhang , C. C. Zhang , D. H. Zhang , H. H. Zhang , H. Y. Zhang , J. Zhang , J. L. Zhang , J. Q. Zhang , J. W. Zhang , J. Y. Zhang , J. Z. Zhang , K. Zhang , L. Zhang , S. F. Zhang , T. J. Zhang , X. Y. Zhang , Y. Zhang , Y. H. Zhang , Y. T. Zhang , Yang Zhang , Yao Zhang , Yu Zhang , Z. H. Zhang , Z. P. Zhang , Z. Y. Zhang , G. Zhao , J. W. Zhao , J. Y. Zhao , J. Z. Zhao , Lei Zhao , Ling Zhao , M. G. Zhao , Q. Zhao , S. J. Zhao , T. C. Zhao , Y. B. Zhao , Z. G. Zhao , A. Zhemchugov , B. Zheng , J. P. Zheng , Y. Zheng , Y. H. Zheng , B. Zhong , L. Zhou , Q. Zhou , X. Zhou , X. K. Zhou , X. R. Zhou , Xiaoyu Zhou , Xu Zhou , A. N. Zhu , J. Zhu , J. Zhu , K. Zhu , K. J. Zhu , S. H. Zhu , X. L. Zhu , Y. C. Zhu , Y. S. Zhu , Z. A. Zhu , J. Zhuang , B. S. Zou , J. H. Zou

A Search for Excited Fermions at HERA

A search for excited fermions f^* of the first generation in e^+p scattering at the collider HERA is presented using H1 data with an integrated luminosity of 37 pb^(-1). All electroweak decays of excited fermions, f^* -> f gamma, f W, f Z…

High Energy Physics - Experiment · Physics 2008-11-26 H1 Collaboration , C. Adloff

Measurement of the inclusive ttgamma cross section at sqrt(s) = 7 TeV with the ATLAS detector

A first measurement of the ttgamma cross section in pp collisions at the LHC using 1.04 fb^-1 of data taken with the ATLAS detector is presented. A total of 122 candidate events were identified in the single electron and single muon…

High Energy Physics - Experiment · Physics 2012-06-26 Johannes Erdmann

eta-photoproduction in the resonance energy region

The $\eta$ production in the nucleon resonance energy region is studied within the unitary coupled-channels effective Lagrangian approach of the Giessen model. We demonstrate that the second peak recently observed in the cross section of…

Nuclear Theory · Physics 2008-11-26 V. Shklyar , H. Lenske , U. Mosel

The $e^+ e^-\to 2(\pi^+\pi^-)\pi^0$, 2(\pi^+\pi^-)\eta$, $K^+ K^-\pi^+\pi^-\pi^0$ and $K^+ K^-\pi^+\pi^-\eta$ Cross Sections Measured with Initial-State Radiation

We study the processes $e^+ e^-\to 2(\pi^+\pi^-)\pi^0\gamma$, $2(\pi^+\pi^-)\eta\gamma$, $K^+ K^-\pi^+\pi^-\pi^0\gamma$ and $K^+ K^-\pi^+\pi^-\eta\gamma$ with the hard photon radiated from the initial state. About 20000, 4300, 5500 and 375…

High Energy Physics - Experiment · Physics 2014-11-18 The BABAR Collaboration , B. Aubert

Transparency ratio in \gamma A -> \eta' A' and the in-medium \eta' width

The photoproduction of \eta'-mesons off different nuclei has been measured with the CBELSA/TAPS detector system for incident photon energies between 1500 - 2200 MeV. The transparency ratio has been deduced and compared to theoretical…

Nuclear Experiment · Physics 2015-06-04 M. Nanova , V. Metag , A. Ramos , E. Oset , I. Jaegle , K. Makonyi , K. Brinkmann , O. Bartholomy , D. Bayadilov , Y. A. Beloglazov , V. Crede , H. Dutz , A. Ehmanns , D. Elsner , K. Essig , R. Ewald , I. Fabry , M. Fuchs , Ch. Funke , R. Gregor , A. B. Gridnev , E. Gutz , S. Höffgen , P. Hoffmeister , I. Horn , J. Junkersfeld , H. Kalinowsky , Frank Klein , Friedrich Klein , E. Klempt , M. Konrad , B. Kopf , B. Krusche , J. Langheinrich , H. Löhner , I. V. Lopatin , J. Lotz , S. Lugert , D. Menze , T. Mertens , J. G. Messchendorp , C. Morales , R. Novotny , M. Ostrick , L. M. Pant , H. van Pee , M. Pfeiffer , A. Roy , A. Radkov , S. Schadmand , Ch. Schmidt , H. Schmieden , B. Schoch , A. Süle , V. V. Sumachev , T. Szczepanek , U. Thoma , D. Trnka , R. Varma , D. Walther , Ch. Wendel

Photon-photon scattering in the resonance region at midrapidity at the LHC

A study is presented to extend the measurements of photon-photon scattering in ultra-peripheral Pb-Pb collisions at the LHC into the mass region of the pseudoscalar resonances $\eta$ and $\eta'$. The elementary photon-photon scattering…

High Energy Physics - Phenomenology · Physics 2018-12-14 R. Schicker , Mariola Klusek-Gawenda , A. Szczurek

On the two-photon contributions to $e^+e^-\to\eta\gamma$ and $e^+e^-\to\eta^\prime\gamma$

Motivated by recent BABAR measurements of the $\gamma^*\to\gamma \eta$ and $\gamma^*\to\gamma \eta^\prime $ transition form factors, we estimate two-photon exchange contributions to the corresponding cross sections. By using a…

High Energy Physics - Phenomenology · Physics 2008-11-26 Z. K. Silagadze

Gamma-rays and positrons from Colliding Wind Binaries

The $\eta$ Carinae binary system is the first $\gamma$-ray binary ever observed which does not contain a compact object. The dense wind of the primary star shocks against the fast light wind coming from the companion star, creating the…

High Energy Astrophysical Phenomena · Physics 2019-09-04 Matteo Balbo , Roland Walter

Photoproduction of eta mesons from the neutron: cross sections and double polarization observable E

Photoproduction of $\eta$ mesons from neutrons} \abstract{Results from measurements of the photoproduction of $\eta$ mesons from quasifree protons and neutrons are summarized. The experiments were performed with the CBELSA/TAPS detector at…

Nuclear Experiment · Physics 2017-04-12 L. Witthauer , M. Dieterle , F. Afzal , A. V. Anisovich , B. Bantes , D. Bayadilov , R. Beck , M. Bichow , K. -T. Brinkmann , S. Böse , Th. Challand , V. Crede , H. Dutz , H. Eberhardt , D. Elsner , R. Ewald , K. Fornet-Ponse , St. Friedrich , F. Frommberger , Ch. Funke , St. Goertz , M. Gottschall , A. Gridnev , M. Grüner , E. Gutzınst , D. Hammann , Ch. Hammann , J. Hannappel , J. Hartmann , W. Hillert , Ph. Hoffmeister , Ch. Honisch , T. Jude , D. Kaiser , H. Kalinowsky , F. Kalischewski , S. Kammer , A. Käser , I. Keshelashvili , P. Klassen , V. Kleber , F. Klein , K. Koop , B. Krusche , M. Lang , I. Lopatin , Ph. Mahlberg , K. Makonyi , V. Metag , W. Meyer , J. Müller , J. Müllers , M. Nanova , V. Nikonov , D. Piontek , G. Reicherz , T. Rostomyan , A. Sarantsev , Ch. Schmidt , H. Schmieden , T. Seifen , V. Sokhoyan , K. Spieker , A. Thiel , U. Thoma , M. Urban , H. van Pee , N. K. Walford , D. Walther , Ch. Wendel , D. Werthmüller , A. Wilson , A. Winnebeck

Evidence for the eta_b(2S) and observation of h_b(1P) -> eta_b(1S) gamma and h_b(2P) -> eta_b(1S) gamma

We report the first evidence for the eta_b(2S) using the h_b(2P)->eta_b(2S)gamma transition and the first observation of the h_b(1P)->eta_b(1S)gamma and h_b(2P)->eta_b(1S)gamma transitions. The mass and width of the eta_b(1S) and eta_b(2S)…

High Energy Physics - Experiment · Physics 2015-06-05 Belle Collaboration , R. Mizuk , D. M. Asner , A. Bondar , T. K. Pedlar , I. Adachi , H. Aihara , K. Arinstein , V. Aulchenko , T. Aushev , T. Aziz , A. M. Bakich , A. Bay , K. Belous , V. Bhardwaj , B. Bhuyan , M. Bischofberger , G. Bonvicini , A. Bozek , M. Bračko , T. E. Browder , V. Chekelian , A. Chen , P. Chen , B. G. Cheon , K. Chilikin , R. Chistov , I. -S. Cho , K. Cho , S. -K. Choi , Y. Choi , J. Dalseno , M. Danilov , Z. Doležal , Z. Drásal , A. Drutskoy , S. Eidelman , D. Epifanov , J. E. Fast , V. Gaur , N. Gabyshev , A. Garmash , B. Golob , J. Haba , T. Hara , K. Hayasaka , H. Hayashii , Y. Horii , Y. Hoshi , W. -S. Hou , Y. B. Hsiung , H. J. Hyun , T. Iijima , A. Ishikawa , R. Itoh , M. Iwabuchi , Y. Iwasaki , T. Iwashita , I. Jaegle , T. Julius , J. H. Kang , P. Kapusta , T. Kawasaki , H. J. Kim , H. O. Kim , J. H. Kim , K. T. Kim , M. J. Kim , Y. J. Kim , K. Kinoshita , B. R. Ko , S. Koblitz , P. Kodyš , S. Korpar , R. T. Kouzes , P. Križan , P. Krokovny , T. Kuhr , T. Kumita , A. Kuzmin , Y. -J. Kwon , J. S. Lange , S. -H. Lee , J. Li , J. Libby , C. Liu , Y. Liu , Z. Q. Liu , D. Liventsev , R. Louvot , D. Matvienko , S. McOnie , K. Miyabayashi , H. Miyata , G. B. Mohanty , D. Mohapatra , A. Moll , N. Muramatsu , R. Mussa , M. Nakao , Z. Natkaniec , C. Ng , S. Nishida , K. Nishimura , O. Nitoh , T. Nozaki , T. Ohshima , S. Okuno , S. L. Olsen , Y. Onuki , P. Pakhlov , G. Pakhlova , C. W. Park , H. Park , R. Pestotnik , M. Petrič , L. E. Piilonen , A. Poluektov , M. Röhrken , Y. Sakai , S. Sandilya , D. Santel , T. Sanuki , Y. Sato , O. Schneider , C. Schwanda , K. Senyo , O. Seon , M. E. Sevior , M. Shapkin , C. P. Shen , T. -A. Shibata , J. -G. Shiu , B. Shwartz , A. Sibidanov , F. Simon , P. Smerkol , Y. -S. Sohn , A. Sokolov , E. Solovieva , S. Stanič , M. Starič , M. Sumihama , T. Sumiyoshi , K. Tanida , G. Tatishvili , Y. Teramoto , I. Tikhomirov , K. Trabelsi , T. Tsuboyama , M. Uchida , S. Uehara , T. Uglov , Y. Unno , S. Uno , P. Vanhoefer , G. Varner , K. E. Varvell , A. Vinokurova , V. Vorobyev , C. H. Wang , M. -Z. Wang , P. Wang , X. L. Wang , M. Watanabe , Y. Watanabe , K. M. Williams , E. Won , B. D. Yabsley , J. Yamaoka , Y. Yamashita , C. Z. Yuan , Z. P. Zhang , V. Zhilich

Could an axion-like particle be hidden in $\eta_c\to\gamma\gamma$?

We discuss the possibility of an axion-like particle being merged in the recent observation of $\eta_c \to \gamma\gamma$ at BESIII and find that it cannot be excluded in the current experimental data. The mass, width, and coupling strengths…

High Energy Physics - Phenomenology · Physics 2025-06-05 Zhi-Jun Li , Zheng-Yun You , Xiao-Rui Lyu