Related papers: An Update on the Hypothetical X17 Particle

Signature of clustering in quantum many body systems probed by the giant dipole resonance

The present experimental study illustrates how large deformations attained by nuclei due to cluster formation are perceived through the giant dipole resonance (GDR) strength function. The high energy GDR $\gamma$-rays have been measured…

Nuclear Experiment · Physics 2017-04-05 Deepak Pandit , Debasish Mondal , Balaram Dey , Srijit Bhattacharya , S. Mukhopadhyay , Surajit Pal , A. De , S. R. Banerjee

A 17 MeV pseudoscalar and the LSND, MiniBooNE and ATOMKI anomalies

In the absence of any new physics signals at the Large Hadron Collider (LHC), anomalous results at low energy experiments have become the subject of increased attention. We focus on three such results from the LSND, MiniBooNE (MB), and…

High Energy Physics - Phenomenology · Physics 2024-10-29 Waleed Abdallah , Raj Gandhi , Tathagata Ghosh , Najimuddin Khan , Samiran Roy , Subhojit Roy

Measuring Top Quark Electroweak Dipole Moments

We analyze the pair-production of top quarks in polarized $e^+e^-$ scattering in the presence of electroweak dipole moments. For this, we consider two $CP$-odd observables which probe both the real and the imaginary parts of these moments.…

High Energy Physics - Phenomenology · Physics 2009-09-25 Frank Cuypers

Indications of an unexpected signal associated with the GW170817 binary neutron star inspiral

We report experimental evidence at the 2.5$\sigma$ level for an unexpected signal associated with the GW170817 binary neutron star inspiral. This evidence derives from a laboratory experiment simultaneously measuring the $\beta$-decay rates…

High Energy Astrophysical Phenomena · Physics 2018-07-04 E. Fischbach , V. E. Barnes , N. Cinko , J. Heim , H. B. Kaplan , D. E. Krause , J. R. Leeman , S. A. Mathews , M. J. Mueterthies , D. Neff , M. Pattermann

Fifth Force and Hyperfine Splitting in Muonic Atoms

The potential existence of a fifth fundamental force, mediated by the X17 boson, has generated significant interest. This force can manifest itself as either a vector or pseudoscalar particle. In order to gain insight into the effective…

High Energy Physics - Phenomenology · Physics 2023-12-21 Jingxuan Chen , Qian Wu , Xurong Chen , Qian Wang

Quantum Chromodynamics Resolution of the ATOMKI Anomaly in ${\rm {^4He}}$ Nuclear Transitions

Observations of anomalous angular correlations in electron-positron pairs produced from excited states of $^{4}$He, $^{8}$Be and $^{12}$C nuclei have been suggested as due to the creation and subsequent decay of a new light particle of mass…

High Energy Physics - Phenomenology · Physics 2025-03-04 Valery Kubarovsky , Jennifer Rittenhouse West , Stanley J. Brodsky

Massless composite bosons formed by the coupled electron-positron pairs, and two-photon angular correlations in the colliding beam reaction $e^{-}e^{+}\to B\gamma\gamma$ with emission of the massless boson

The approach in which the electron and positron are treated as ordinary, different particles, each being characterized by the complete set of the Dirac plane waves, is examined. This completely symmetric representation that is beyond the…

High Energy Physics - Phenomenology · Physics 2017-10-20 A. I. Agafonov

Using Circular Polarisation to Test the Composition and Dynamics of Astrophysical Particle Accelerators

We investigate the production of circularly polarised X and gamma-ray signals in cosmic accelerators such as supernova remnants and AGN jets. Proton-proton and proton-photon collisions within these sites produce a charge asymmetry in the…

High Energy Astrophysical Phenomena · Physics 2021-01-04 Céline Boehm , Céline Degrande , Jakub Scholtz , Aaron C. Vincent

Ab initio investigations of A=8 nuclei: $\alpha{-}\alpha$ scattering, deformation in $^8$He, radiative capture of protons on $^7$Be and $^7$Li and the X17 boson

We apply the No-Core Shell Model with Continuum (NCSMC) that is capable of describing both bound and unbound states in light nuclei in a unified way with chiral two- and three-nucleon interactions as the only input. The NCSMC can predict…

Nuclear Theory · Physics 2022-12-05 P. Navratil , K. Kravvaris , P. Gysbers , C. Hebborn , G. Hupin , S. Quaglioni

Observation of a Doubly-strange Hyperon $\Xi(1720)$ in $J/\psi\rightarrow{}K^{-}\Sigma^0\bar{\Xi}^{+}+c.c.$

Based on a sample of $(10087 \pm 44) \times 10^6$ $J/\psi$ events collected with the BESIII detector at BEPCII, we report the first observation of the decay $J/\psi \rightarrow K^- \Sigma^0 \bar{\Xi}^++c.c.$. A partial wave analysis is…

High Energy Physics - Experiment · Physics 2026-05-01 BESIII Collaboration , M. Ablikim , M. N. Achasov , P. Adlarson , X. C. Ai , C. S. Akondi , R. Aliberti , A. Amoroso , Q. An , Y. H. An , Y. Bai , O. Bakina , H. -R. Bao , X. L. Bao , M. Barbagiovanni , 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 , D. Cabiati , 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 , W. Chen , X. R. Chen , X. T. Chen , X. Y. Chen , Y. B. Chen , Y. Q. Chen , Z. K. Chen , J. 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 , E. Di Fiore , X. X. Ding , Y. Ding , Y. X. Ding , Yi. Ding , J. Dong , L. Y. Dong , M. Y. Dong , X. Dong , M. C. Du , S. X. Du , Shaoxu Du , X. L. Du , Y. Q. Du , Y. Y. Duan , Z. H. Duan , P. Egorov , G. F. Fan , J. J. Fan , Y. H. Fan , J. Fang , Jin 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. Y. Gao , Yunong 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. Gollub , J. B. Gong , J. D. Gong , L. Gong , W. X. Gong , W. Gradl , S. Gramigna , M. Greco , M. D. Gu , M. H. Gu , C. Y. Guan , A. Q. Guo , H. Guo , J. N. Guo , L. B. Guo , M. J. Guo , R. P. Guo , X. Guo , Y. P. Guo , Z. Guo , A. Guskov , J. Gutierrez , J. Y. Han , T. T. Han , X. Han , F. Hanisch , K. D. Hao , X. Q. Hao , F. A. Harris , C. Z. He , K. K. 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 , Y. X. 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 , Y. Y. Ji , L. K. Jia , X. Q. Jia , D. Jiang , H. B. Jiang , S. J. Jiang , X. S. Jiang , Y. Jiang , J. B. Jiao , J. K. Jiao , Z. Jiao , L. C. L. Jin , S. Jin , Y. Jin , M. Q. Jing , X. M. Jing , T. Johansson , S. Kabana , X. L. Kang , X. S. Kang , B. C. Ke , V. Khachatryan , A. Khoukaz , O. B. Kolcu , B. Kopf , L. Kröger , L. Krümmel , Y. Y. Kuang , 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. H. Li , C. K. Li , Chunkai Li , Cong Li , D. M. Li , F. Li , G. Li , H. B. Li , H. J. Li , H. L. Li , H. N. Li , H. P. Li , Hui Li , J. N. Li , J. S. Li , J. W. Li , K. Li , K. L. Li , L. J. Li , Lei Li , M. H. Li , M. R. Li , M. T. Li , P. L. Li , P. R. Li , Q. M. Li , Q. X. Li , R. Li , S. Li , S. X. Li , S. Y. Li , Shanshan Li , T. Li , T. Y. Li , W. D. Li , W. G. Li , X. Li , X. H. Li , X. K. Li , X. L. Li , X. Y. Li , X. Z. Li , Y. Li , Y. G. Li , Y. P. Li , Z. H. Li , Z. J. Li , Z. L. Li , Z. X. Li , Z. Y. Li , C. Liang , H. Liang , Y. F. Liang , Y. T. Liang , G. R. Liao , L. B. Liao , M. H. Liao , Y. P. Liao , J. Libby , A. Limphirat , C. C. Lin , C. X. Lin , D. X. Lin , T. Lin , B. J. Liu , B. X. Liu , C. Liu , C. X. Liu , F. Liu , F. H. Liu , Feng Liu , G. M. Liu , H. Liu , H. B. Liu , H. M. Liu , Huihui Liu , J. B. Liu , J. J. Liu , K. Liu , K. Y. Liu , Ke Liu , Kun Liu , L. Liu , L. C. Liu , Lu Liu , M. H. Liu , P. L. Liu , Q. Liu , S. B. Liu , T. Liu , W. M. Liu , W. T. Liu , X. Liu , X. K. Liu , X. L. Liu , X. P. Liu , X. Y. Liu , Y. Liu , Y. B. Liu , Yi Liu , Z. A. Liu , Z. D. Liu , Z. L. Liu , Z. Q. Liu , Z. X. Liu , Z. Y. Liu , X. C. Lou , H. J. Lu , J. G. Lu , X. L. Lu , Y. Lu , Y. H. Lu , Y. P. Lu , Z. H. Lu , C. L. Luo , J. R. Luo , J. S. Luo , M. X. Luo , T. Luo , X. L. Luo , Z. Y. Lv , X. R. Lyu , Y. F. Lyu , Y. H. Lyu , F. C. Ma , H. L. Ma , Heng Ma , J. L. Ma , L. L. Ma , L. R. Ma , Q. M. Ma , R. Q. Ma , R. Y. Ma , T. Ma , X. T. Ma , X. Y. Ma , Y. M. Ma , F. E. Maas , I. MacKay , M. Maggiora , S. Maity , S. Malde , Q. A. Malik , H. X. Mao , Y. J. Mao , Z. P. Mao , S. Marcello , A. Marshall , F. M. Melendi , Y. H. Meng , Z. X. Meng , G. Mezzadri , H. Miao , T. J. Min , R. E. Mitchell , X. H. Mo , B. Moses , N. Yu. Muchnoi , J. Muskalla , Y. Nefedov , F. Nerling , H. Neuwirth , Z. Ning , S. Nisar , Q. L. Niu , W. D. Niu , Y. Niu , C. Normand , S. L. Olsen , Q. Ouyang , S. Pacetti , X. Pan , Y. Pan , A. Pathak , Y. P. Pei , M. Pelizaeus , G. L. Peng , H. P. Peng , X. J. Peng , Y. Y. Peng , K. Peters , K. Petridis , J. L. Ping , R. G. Ping , S. Plura , V. Prasad , L. Pöpping , F. Z. Qi , H. R. Qi , M. Qi , S. Qian , W. B. Qian , C. F. Qiao , J. H. Qiao , J. J. Qin , J. L. Qin , L. Q. Qin , L. Y. Qin , P. B. Qin , X. P. Qin , X. S. Qin , Z. H. Qin , J. F. Qiu , Z. H. Qu , J. Rademacker , C. F. Redmer , A. Rivetti , M. Rolo , G. Rong , S. S. Rong , F. Rosini , Ch. Rosner , M. Q. Ruan , N. Salone , A. Sarantsev , Y. Schelhaas , M. Schernau , K. 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 , Ch. Y. Shi , H. Shi , J. L. Shi , J. Y. Shi , M. H. 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 , M. Stolte , 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 , W. Y. Sun , Y. C. Sun , Y. H. Sun , Y. J. Sun , Y. Z. Sun , Z. Q. Sun , Z. T. Sun , H. Tabaharizato , C. J. Tang , G. Y. Tang , J. Tang , J. J. Tang , L. F. Tang , Y. A. Tang , Z. H. Tang , L. Y. Tao , M. Tat , J. X. Teng , J. Y. Tian , W. H. Tian , Y. Tian , Z. F. Tian , I. Uman , E. van der Smagt , B. Wang , Bin Wang , Bo Wang , C. Wang , Chao Wang , Cong Wang , D. Y. Wang , H. J. Wang , H. R. Wang , J. Wang , J. J. Wang , J. P. Wang , K. Wang , L. L. Wang , L. W. Wang , M. Wang , Mi Wang , N. Y. Wang , S. Wang , Shun Wang , T. Wang , T. J. Wang , W. Wang , W. P. Wang , X. F. Wang , X. L. Wang , X. N. Wang , Xin Wang , Y. Wang , Y. D. Wang , Y. F. Wang , Y. H. Wang , Y. J. Wang , Y. L. Wang , Y. N. Wang , Yanning Wang , Yaqian Wang , Yi Wang , Yuan Wang , Z. Wang , Z. L. Wang , Z. Q. Wang , Z. Y. Wang , Zhi Wang , Ziyi Wang , D. Wei , D. H. Wei , D. J. Wei , H. R. Wei , F. Weidner , H. R. Wen , S. P. Wen , U. Wiedner , G. Wilkinson , M. Wolke , J. F. Wu , L. H. Wu , L. J. Wu , Lianjie Wu , S. G. Wu , S. M. Wu , X. W. Wu , Z. Wu , H. L. Xia , L. Xia , B. H. Xiang , D. Xiao , G. Y. Xiao , H. Xiao , Y. L. Xiao , Z. J. Xiao , C. Xie , K. J. Xie , Y. Xie , Y. G. Xie , Y. H. Xie , Z. P. Xie , T. Y. Xing , D. B. Xiong , C. J. Xu , G. F. Xu , H. Y. Xu , Q. J. Xu , Q. N. Xu , T. D. Xu , X. P. Xu , Y. Xu , Y. C. Xu , Z. S. Xu , F. Yan , L. Yan , W. B. Yan , W. C. Yan , W. H. Yan , W. P. Yan , X. Q. Yan , Y. Y. Yan , H. J. Yang , H. L. Yang , H. X. Yang , J. H. Yang , R. J. Yang , X. Y. Yang , Y. Yang , Y. H. Yang , Y. M. Yang , Y. Q. Yang , Y. Z. Yang , Youhua Yang , Z. Y. Yang , Z. P. Yao , M. Ye , M. H. Ye , Z. J. Ye , Junhao Yin , Z. Y. You , B. X. Yu , C. X. Yu , G. Yu , J. S. Yu , L. W. Yu , T. Yu , X. D. Yu , Y. C. Yu , Yongchao Yu , C. Z. Yuan , H. Yuan , J. Yuan , Jie Yuan , L. Yuan , M. K. Yuan , S. H. Yuan , Y. Yuan , C. X. Yue , Ying Yue , A. A. Zafar , F. R. Zeng , S. H. Zeng , X. Zeng , Y. J. Zeng , Yujie Zeng , Y. C. Zhai , Y. H. Zhan , B. L. Zhang , B. X. Zhang , D. H. Zhang , G. Y. Zhang , Gengyuan Zhang , H. Zhang , H. C. Zhang , H. H. Zhang , H. Q. Zhang , H. R. Zhang , H. Y. Zhang , Han Zhang , J. Zhang , J. J. Zhang , J. L. Zhang , J. Q. Zhang , J. S. Zhang , J. W. Zhang , J. X. Zhang , J. Y. Zhang , J. Z. Zhang , Jianyu Zhang , Jin Zhang , Jiyuan Zhang , L. M. Zhang , Lei Zhang , N. Zhang , P. Zhang , Q. Zhang , Q. Y. Zhang , Q. Z. Zhang , R. Y. Zhang , S. H. Zhang , S. N. Zhang , Shulei Zhang , X. M. Zhang , X. Y. Zhang , Y. Zhang , Y. T. Zhang , Y. H. Zhang , Y. P. Zhang , Yu Zhang , Z. Zhang , Z. D. Zhang , Z. H. Zhang , Z. L. Zhang , Z. X. Zhang , Z. Y. Zhang , Zh. Zh. Zhang , Zhilong Zhang , Ziyang Zhang , Ziyu Zhang , G. Zhao , J. -P. Zhao , J. Y. Zhao , J. Z. Zhao , L. Zhao , Lei Zhao , M. G. Zhao , R. P. Zhao , S. J. Zhao , Y. B. Zhao , Y. L. Zhao , Y. P. Zhao , Y. X. Zhao , Z. G. Zhao , A. Zhemchugov , B. Zheng , B. M. Zheng , J. P. Zheng , W. J. Zheng , W. Q. 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. X. Zhu , Lin 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 , M. Zhuge , J. H. Zou , J. Zu

Open Questions Related to Bose-Einstein Correlations in e+ e- --> Hadrons

Questions concerning the Bose-Einstein (BEC) and Fermi-Dirac (FDC) correlations of hadrons produced in $e^+e^-$ collisions are discussed. Among them the emitter dimension $r$ as a function of $\sqrt{s_{ee}}$ and the hadron mass, the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Gideon Alexander

Directional `superradiant' collisions: bosonic amplification of atom pairs emitted from an elongated Bose-Einstein condensate

We study spontaneous directionality in the bosonic amplification of atom pairs emitted from an elongated Bose-Einstein condensate (BEC), an effect analogous to `superradiant' emission of atom-photon pairs. Using a simplified model, we make…

Condensed Matter · Physics 2009-11-07 A. Vardi , M. G. Moore

The 18Ne(a,p)21Na breakout reaction in x-ray bursts: experimental determination of spin-parities for alpha resonances in 22Mg via resonant elastic scattering of 21Na+p

The $^{18}$Ne($\alpha$,$p$)$^{21}$Na reaction provides a pathway for breakout from the hot CNO cycles to the $rp$-process in type I x-ray bursts. To better determine this astrophysical reaction rate, the resonance parameters of the compound…

Solar and Stellar Astrophysics · Physics 2015-06-12 J. J. He , L. Y. Zhang , A. Parikh , S. W. Xu , H. Yamaguchi , D. Kahl , S. Kubono , J. Hu , P. Ma , S. Z. Chen , Y. Wakabayashi , B. H. Sun , H. W. Wang , W. D. Tian , R. F. Chen , B. Guo , T. Hashimoto , Y. Togano , S. Hayakawa , T. Teranishi , N. Iwasa , T. Yamada , T. Komatsubara

First Energy and Angle differential Measurements of e^+e^- -pairs emitted by Internal Pair Conversion of excited Heavy Nuclei

We present the first energy and angle resolved measurements of e+e- pairs emitted from heavy nuclei (Z>=40) at rest by internal pair conversion (IPC) of transitions with energies of less than 2MeV as well as recent theoretical results using…

Nuclear Experiment · Physics 2009-10-30 U. Leinberger , E. Berdermann , F. Heine , S. Heinz , O. Joeres , P. Kienle , I. Koenig , W. Koenig , C. Kozhuharov , A. Schroeter , H. Tsertos , C. Hofmann , G. Soff

Higgs Bosons: Intermediate Mass Range at e+e- Colliders

We elaborate on the production of the Standard Model Higgs particle at high-energy $e^+e^-$ colliders through the reaction $e^+e^- \rightarrow ZH$. Particular emphasis is put on the intermediate mass range. In addition to the signal we…

High Energy Physics - Phenomenology · Physics 2009-09-15 V. Barger , K. Cheung , A. Djouadi , B. A. Kniehl , P. M. Zerwas

Production of Neutral and Doubly Charged Partners of D_{s0}^+(2317) Revisited

Rates for productions of neutral and doubly charged partners of D_{s0}^+(2317) in B meson decays are studied by using a hard D meson approximation in the infinite momentum frame, and the results are of the same order of magnitude as that of…

High Energy Physics - Phenomenology · Physics 2016-04-22 Kunihiko Terasaki

A Hard X-ray View of Accreting X-ray Binary Pulsars

The study of the hard (E>10 keV) energy spectra of X-ray binary pulsars can give a wealth of information on the physical processes that occur close to the neutron star surface. Extreme matter regimes are probed, and precious information on…

Astrophysics · Physics 2007-05-23 Mauro Orlandini

The Bose-Einstein Condensate of G-wave Molecules and Its Intrinsic Angular Momentum

The recent report on the realization of a Bose-Einstein condensate of G-wave molecule made up of bound pairs of Cesium bosons is a surprise. These molecules are created at the G-wave resonance at 19.87G, where the severe three-body loss…

Quantum Gases · Physics 2021-01-15 Tin-Lun Ho

Search for a light exotic particle in J/psi radiative decays

Using a data sample containing 1.06x10^8 psi' events collected with the BESIII detector at the BEPCII electron-positron collider, we search for a light exotic particle X in the process psi' -> pi^+ pi^- J/psi, J/psi -> gamma X, X -> mu^+…

High Energy Physics - Experiment · Physics 2013-07-22 BESIII Collaboration

Some properties of the newly observed X(1835) state at BES

Recently the BES collaboration has announced observation of a resonant state in the $\pi^+\pi^- \eta'$ spectrum in $J/\psi \to \gamma \pi^+\pi^-\eta'$ decay. Fitting the data with a $0^{-+}$ state, the mass is determined to be 1833.7 MeV…

High Energy Physics - Phenomenology · Physics 2008-11-26 Xiao-Gang He , Xue-Qian Li , Xiang Liu , J. P. Ma