Related papers: The X17 boson and the d(p,e+ e-)3He and d(n,e+ e-)…

Production of eta and 3pi mesons in the pd->3HeX reaction at 1360 and 1450 MeV

The cross sections of the pd -> 3He eta, pd -> 3He pi0 pi0 pi0 and pd -> 3He pi+ pi- pi0 reactions have been measured at beam kinetic energies T_p= 1360 MeV and T_p= 1450 MeV using the CELSIUS/WASA detector setup. At both energies, the…

Nuclear Experiment · Physics 2014-11-20 K. Schoenning , Chr. Bargholtz , M. Bashkanov , M. Berlowski , D. Bogoslawsky , H. Calen , H. Clement , L. Demiroers , C. Ekstroem , K. Fransson , L. Geren , L. Gustafsson , B. Hoeistad , G. Ivanov , M. Jacewicz , E. Jiganov , T. Johansson , S. Keleta , O. Khakimova , F. Kren , S. Kullander , A. Kupsc , A. Kuzmin , K. Lindberg , P. Marciniewski , B. Morosov , W. Oelert , C. Pauly , H. Petren , Y. Petukhov , A. Povtorejko , W. Scobel , R. Shafigullin , B. Shwartz , T. Skorodko , V. Sopov , J. Stepaniak , P. -E. tegner , P. Thoerngren Engblom , V. Tikhomirov , A. Turowiecki , G. J. Wagner , M. Wolke , J. Zabierowski , I. Zartova , J. Zlomanczuk

X(16.7) Production in Electron-Position Collision

The anomaly found in the excited $^8\text{Be}$ nuclear transition to its ground state is attributed to a spin-1 gauge boson $X(16.7)$. To hunt for this boson, we propose two traps: $e^+e^-\to X\gamma$ and $J/\psi\to X\gamma$, both following…

High Energy Physics - Phenomenology · Physics 2018-06-05 Jun Jiang , Long-Bin Chen , Yi Liang , Cong-Feng Qiao

Production of $e^{+} e^{-}$ in proton-lead collision: photon-photon fusion

We analyze the photon-initiated processes for production of $ e ^ + e ^- $ pairs in proton-nucleus collisions at LHC energy, taking into account both elastic processes and proton dissociations in the low-mass region (LMR) and…

High Energy Physics - Phenomenology · Physics 2022-12-07 Barbara Linek , Marta Łuszczak , Wolfgang Schäfer , Antoni Szczurek

Proton-$\rm ^3He$ elastic scattering at intermediate energies

We present a precise measurement of the cross section, proton and $\rm ^3He$ analyzing powers, and spin correlation coefficient $C_{y,y}$ for $p$-$\rm ^3He$ elastic scattering near 65 MeV, and a comparison with rigorous four-nucleon…

Nuclear Experiment · Physics 2021-04-21 A. Watanabe , S. Nakai , Y. Wada , K. Sekiguchi , A. Deltuva , T. Akieda , D. Etoh , M. Inoue , Y. Inoue , K. Kawahara , H. Kon , K. Miki , T. Mukai , D. Sakai , S. Shibuya , Y. Shiokawa , T. Taguchi , H. Umetsu , Y. Utsuki , M. Watanabe , S. Goto , K. Hatanaka , Y. Hirai , T. Ino , D. Inomoto , A. Inoue , S. Ishikawa , M. Itoh , H. Kanda , H. Kasahara , N. Kobayashi , Y. Maeda , S. Mitsumoto , S. Nakamura , K. Nonaka , H. J. Ong , H. Oshiro , Y. Otake , H. Sakai , A. Taketani , A. Tamii , D. T. Tran , T. Wakasa , Y. Wakabayashi , T. Wakui

Search for a hypothetical gauge boson and dark photons in charmonium transitions

We report a direct search for a new gauge boson, $X$, with a mass of $17~\text{MeV}/c^2$, which could explain the anomalous excess of $e^+e^-$ pairs observed in the $^8\text{Be}$ nuclear transitions. The search is conducted in the…

High Energy Physics - Experiment · Physics 2026-02-18 BESIII Collaboration , M. Ablikim , M. N. Achasov , P. Adlarson , X. C. Ai , R. Aliberti , A. Amoroso , Q. An , Y. Bai , O. Bakina , Y. Ban , H. -R. Bao , V. Batozskaya , K. Begzsuren , N. Berger , M. Berlowski , M. B. Bertani , D. Bettoni , F. Bianchi , E. Bianco , A. Bortone , I. Boyko , R. A. Briere , A. Brueggemann , H. Cai , M. H. Cai , X. Cai , A. Calcaterra , G. F. Cao , N. Cao , S. A. Cetin , X. Y. Chai , J. F. Chang , T. T. Chang , G. R. Che , Y. Z. Che , C. H. Chen , Chao Chen , G. Chen , H. S. Chen , H. Y. Chen , M. L. Chen , S. J. Chen , S. M. Chen , T. Chen , X. R. Chen , X. T. Chen , X. Y. Chen , Y. B. Chen , Y. Q. Chen , Z. K. Chen , J. C. Cheng , L. N. Cheng , S. K. Choi , X. Chu , G. Cibinetto , F. Cossio , J. Cottee-Meldrum , H. L. Dai , J. P. Dai , X. C. Dai , A. Dbeyssi , R. E. de Boer , D. Dedovich , C. Q. Deng , Z. Y. Deng , A. Denig , I. Denisenko , M. Destefanis , F. De Mori , X. X. Ding , Y. Ding , Y. X. Ding , J. Dong , L. Y. Dong , M. Y. Dong , X. Dong , M. C. Du , S. X. Du , S. X. Du , X. L. Du , Y. Y. Duan , Z. H. Duan , P. Egorov , G. F. Fan , J. J. Fan , Y. H. Fan , J. Fang , J. Fang , S. S. Fang , W. X. Fang , Y. Q. Fang , L. Fava , F. Feldbauer , G. Felici , C. Q. Feng , J. H. Feng , L. Feng , Q. X. Feng , Y. T. Feng , M. Fritsch , C. D. Fu , J. L. Fu , Y. W. Fu , H. Gao , Y. Gao , Y. N. Gao , Y. N. Gao , Y. Y. Gao , Z. Gao , S. Garbolino , I. Garzia , L. Ge , P. T. Ge , Z. W. Ge , C. Geng , E. M. Gersabeck , A. Gilman , K. Goetzen , J. D. Gong , L. Gong , W. X. Gong , W. Gradl , S. Gramigna , M. Greco , M. H. Gu , C. Y. Guan , A. Q. Guo , J. N. Guo , L. B. Guo , M. J. Guo , R. P. Guo , X. Guo , Y. P. Guo , A. Guskov , J. Gutierrez , T. T. Han , F. Hanisch , K. D. Hao , X. Q. Hao , F. A. Harris , C. Z. He , K. L. He , F. H. Heinsius , C. H. Heinz , Y. K. Heng , C. Herold , P. C. Hong , G. Y. Hou , X. T. Hou , Y. R. Hou , Z. L. Hou , H. M. Hu , J. F. Hu , Q. P. Hu , S. L. Hu , T. Hu , Y. Hu , Z. M. Hu , G. S. Huang , K. X. Huang , L. Q. Huang , P. Huang , X. T. Huang , Y. P. Huang , Y. S. Huang , T. Hussain , N. Hüsken , N. in der Wiesche , J. Jackson , Q. Ji , Q. P. Ji , W. Ji , X. B. Ji , X. L. Ji , X. Q. Jia , Z. K. Jia , D. Jiang , H. B. Jiang , P. C. Jiang , S. J. Jiang , X. S. Jiang , Y. Jiang , J. B. Jiao , J. K. Jiao , Z. Jiao , S. Jin , Y. Jin , M. Q. Jing , X. M. Jing , T. Johansson , S. Kabana , N. Kalantar-Nayestanaki , X. L. Kang , X. S. Kang , M. Kavatsyuk , B. C. Ke , V. Khachatryan , A. Khoukaz , O. B. Kolcu , B. Kopf , M. Kuessner , X. Kui , N. Kumar , A. Kupsc , W. Kühn , Q. Lan , W. N. Lan , T. T. Lei , M. Lellmann , T. Lenz , C. Li , C. Li , C. H. Li , C. K. Li , D. M. Li , F. Li , G. Li , H. B. Li , H. J. Li , H. L. Li , H. N. Li , Hui Li , J. R. Li , J. S. Li , J. W. Li , K. Li , K. L. Li , L. J. Li , Lei Li , M. H. Li , M. R. Li , P. L. Li , P. R. Li , Q. M. Li , Q. X. Li , R. Li , S. X. Li , Shanshan Li , T. Li , T. Y. Li , W. 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Schoenning , M. Scodeggio , W. Shan , X. Y. Shan , Z. J. Shang , J. F. Shangguan , L. G. Shao , M. Shao , C. P. Shen , H. F. Shen , W. H. Shen , X. Y. Shen , B. A. Shi , H. Shi , J. L. Shi , J. Y. Shi , S. Y. Shi , X. Shi , H. L. Song , J. J. Song , M. H. Song , T. Z. Song , W. M. Song , Y. X. Song , Zirong Song , S. Sosio , S. Spataro , S Stansilaus , F. Stieler , S. S Su , G. B. Sun , G. X. Sun , H. Sun , H. K. Sun , J. F. Sun , K. Sun , L. Sun , R. Sun , S. S. Sun , T. Sun , Y. C. Sun , Y. H. Sun , Y. J. Sun , Y. Z. Sun , Z. Q. Sun , Z. T. Sun , C. J. Tang , G. Y. Tang , J. Tang , J. J. Tang , L. F. Tang , Y. A. Tang , L. Y. Tao , M. Tat , J. X. Teng , J. Y. Tian , W. H. Tian , Y. Tian , Z. F. Tian , I. Uman , B. Wang , B. Wang , Bo Wang , C. Wang , C. Wang , Cong Wang , D. Y. Wang , H. J. Wang , J. Wang , J. J. Wang , J. P. Wang , K. Wang , L. L. Wang , L. W. Wang , M. Wang , M. Wang , N. Y. Wang , S. Wang , S. Wang , T. Wang , T. J. Wang , W. Wang , W. P. Wang , X. Wang , X. F. 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Zhao , L. Zhao , M. G. Zhao , S. J. Zhao , Y. B. Zhao , Y. L. Zhao , Y. X. Zhao , Z. G. Zhao , A. Zhemchugov , B. Zheng , B. M. Zheng , J. P. Zheng , W. J. Zheng , X. R. Zheng , Y. H. Zheng , B. Zhong , C. Zhong , H. Zhou , J. Q. Zhou , S. Zhou , X. Zhou , X. K. Zhou , X. R. Zhou , X. Y. Zhou , Y. X. Zhou , Y. Z. Zhou , A. N. Zhu , J. Zhu , K. Zhu , K. J. Zhu , K. S. Zhu , L. Zhu , L. X. Zhu , S. H. Zhu , T. J. Zhu , W. D. Zhu , W. J. Zhu , W. Z. Zhu , Y. C. Zhu , Z. A. Zhu , X. Y. Zhuang , J. H. Zou , J. Zu

Production of $e^+e^-$ pairs to all orders in $Z\alpha$ for collisions of high-energy muons with heavy nuclei

The $e^+e^-$ pair production in collisions of muon with atoms is considered to all orders in the parameter $Z\alpha$. We obtain energy distribution of $e^+$ and $e^-$ as well as energy loss of muon passing through matter with heavy atoms.…

High Energy Physics - Phenomenology · Physics 2009-10-31 D. Ivanov , E. A. Kuraev , A. Schiller , V. G. Serbo

A new anomaly observed in $^4$He supports the existence of the hypothetical X17 particle

Energy-sum and angular correlation spectra of $e^+e^-$ pairs produced in the $^{3}$H(p,$\gamma$)$^{4}$He nuclear reaction have been studied at $E_p$=510, 610 and 900 keV proton energies. The main features of the spectra can be understood by…

Nuclear Experiment · Physics 2021-10-27 A. J. Krasznahorkay , M. Csatlós , L. Csige , J. Gulyás , A. Krasznahorkay , B. M. Nyakó , I. Rajta , J. Timár , I. Vajda , N. J. Sas

Associated production of H^{\pm} and W^{\mp} in high-energy e+e- collisions in the Minimal Supersymmetric Standard Model

We study the associated production of the charged Higgs boson and W^{\pm} gauge boson in high energy e+e- collisions in the Minimal Supersymmetric Standard Model (MSSM). This associated production, which first arises at the one loop level,…

High Energy Physics - Phenomenology · Physics 2009-11-07 Heather E. Logan , Shufang Su

New results on the pd --> 3He eta production near threshold

Measurements on the eta meson production in proton-deuteron collisions have been performed using the COSY-11 facility at COSY Juelich. Here we present preliminary results on total and differential cross sections for the pd --> 3He eta…

High Energy Physics - Experiment · Physics 2009-03-20 H. -H. Adam , A. Khoukaz , N. Lang , T. Lister , R. Santo , S. Steltenkamp , R. Czyzykiewicz , M. Janusz , L. Jarczyk , B. Kamys , P. Moskal , C. Piskor-Ignatowicz , J. Przerwa , J. Smyrski , D. Grzonka , K. Kilian , W. Oelert , T. Sefzick , P. Winter , M. Wolke , P. Wuestner , A. Budzanowski , T. Rozek , M. Siemaszko , W. Zipper

Exclusive production of heavy charged Higgs boson pairs in the $p p \to p p H^+ H^-$ reaction at the LHC and a future circular collider

We calculate differential cross sections for exclusive production of heavy charged scalar, weakly interacting particles (charged Higgs bosons, charged technipions, etc.) via photon-photon exchanges in the $p p \to p p H^+ H^-$ reaction with…

High Energy Physics - Phenomenology · Physics 2015-05-13 Piotr Lebiedowicz , Antoni Szczurek

A Covariant OBE Model for $\eta$ Production in NN Collisions

A relativistic covariant one boson exchange model, previously applied to describe elastic nucleon-nucleon scattering, is extended to study $\eta$ production in NN collisions. The transition amplitude for the elementary BN->$\eta$N process…

High Energy Physics - Phenomenology · Physics 2009-10-30 E. Gedalin , A. Moalem , L. Razdolskaja

Fifth Force and Hyperfine Splitting in Bound Systems

Two recent experimental observations at the ATOMKI Institute of the Hungarian Academy of Sciences (regarding the angular emission pattern of electron-positron pairs from nuclear transitions from excited states in 8Be and 4He) indicate the…

High Energy Physics - Phenomenology · Physics 2020-07-01 Ulrich D. Jentschura

Can a protophobic vector boson explain the ATOMKI anomaly?

In 2016, the ATOMKI collaboration announced [PRL {\bf 116}, 042501 (2016)] observing an unexpected enhancement of the $e^+-e^-$ pair production signal in one of the $^8$Be nuclear transitions induced by an incident proton beam on a $^7$Li…

High Energy Physics - Phenomenology · Physics 2021-01-28 Xilin Zhang , Gerald A. Miller

Search for New Physics in e-e- Scattering

Considering the physics potential of an e-e- collider in the TeV energy range, we indicate a few interesting examples for exotic processes and discuss the standard model backgrounds. Focussing on pair production of weak gauge bosons, we…

High Energy Physics - Phenomenology · Physics 2009-10-28 F. Cuypers , K. Kolodziej , R. Rueckl

Hunting the elusive $X17$ in CE$\nu$NS at the ESS

The so-called $X17$ particle has been proposed in order to explain a very significant resonant behaviour (in both the angular separation and invariant mass) of $e^+e^-$ pairs produced during a nuclear transition of excited $^8$Be, $^4$He…

High Energy Physics - Phenomenology · Physics 2025-09-19 Joakim Cederkäll , Yaşar Hiçyılmaz , Else Lytken , Stefano Moretti , Johan Rathsman

Single Intermediate Vector Boson production in e+e- collisions at sqrt(s) = 183 - 209 GeV

The production of single charged and neutral intermediate vector bosons in e+e- collisions has been studied in the data collected by the DELPHI experiment at LEP at centre-of-mass energies between 183 and 209 GeV, corresponding to an…

High Energy Physics - Experiment · Physics 2008-11-26 The DELPHI Collaboration , J. Abdallah

D' Production in Heavy Ion Collisions

The production of d' dibaryons in heavy ion collisions due to the elementary process NN -> d' + pion is considered. The cross section NN -> d' + pion is estimated using the vacuum d' width = 0.5 MeV extracted from data on the double charge…

Nuclear Theory · Physics 2009-10-31 S. M. Kiselev , M. I. Krivoruchenko , B. V. Martemyanov , Amand Faessler , C. Fuchs

Further search for a neutral boson with a mass around 9 MeV/c2

Two dedicated experiments on internal pair conversion (IPC) of isoscalar M1 transitions were carried out in order to test a 9 MeV/c2 X-boson scenario. In the 7Li(p,e+e-)8Be reaction at 1.1 MeV proton energy to the predominantly T=0 level at…

High Energy Physics - Phenomenology · Physics 2009-11-07 F. W. N. de Boer , K. Bethge , H. Bokemeyer , R. van Dantzig , J. van Klinken , V. Mironov , K. A. Mueller , K. E. Stiebing

Study of Z Boson Pair Production in e+e- Collisions at LEP at \sqrt{s}=189 GeV

The pair production of Z bosons is studied using the data collected by the L3 detector at LEP in 1998 in e+e- collisions at a centre-of-mass energy of 189 GeV. All the visible final states are considered and the cross section of this…

High Energy Physics - Experiment · Physics 2012-08-27 L3 Collaboration

An Electron Fixed Target Experiment to Search for a New Vector Boson A' Decaying to e+e-

We describe an experiment to search for a new vector boson A' with weak coupling alpha' > 6 x 10^{-8} alpha to electrons (alpha=e^2/4pi) in the mass range 65 MeV < m_A' < 550 MeV. New vector bosons with such small couplings arise naturally…

High Energy Physics - Phenomenology · Physics 2015-05-18 Rouven Essig , Philip Schuster , Natalia Toro , Bogdan Wojtsekhowski