English
Related papers

Related papers: Comment on Neutron-Proton Spin-Correlation Paramet…

200 papers

In his recent publication of a NN phase shift analysis below 160 MeV, Henneck reports relatively large values for the mixing parameter $\epsilon_1$. Based on these results, Henneck suggests that the strength of the $\rho$-meson tensor…

Nuclear Theory · Physics 2009-09-25 G. E. Brown , R. Machleidt

At the Cooler Synchrotron COSY/J\"ulich spin correlation parameters in elastic proton-proton (pp) scattering have been measured with a 2.11 GeV polarized proton beam and a polarized hydrogen atomic beam target. We report results for…

Motivated by the recent measurement of proton-proton spin-correlation parameters up to 2.5 GeV laboratory energy, we investigate models for nucleon-nucleon (NN) scattering above 1 GeV. Signatures for a gradual failure of the traditional…

Nuclear Theory · Physics 2009-11-10 K. O. Eyser , R. Machleidt , W. Scobel , the EDDA Collaboration

We study the possibility of measuring parity-violating pion-nucleon coupling h_{\pi NN}^{(1)} from \pi^+ electroproton production in the threshold region. We calculate the electron-helicity asymmetry in terms of h_{\pi NN}^{(1)} and the…

Nuclear Theory · Physics 2009-11-06 Jiunn-Wei Chen , Xiangdong Ji

Background: The recent disagreement between the proton charge radius extracted from Lamb shift measurements of muonic and electronic hydrogen invites speculation that new physics may be to blame. Several proposals have been made for new…

High Energy Physics - Phenomenology · Physics 2013-05-30 Carl E. Carlson , Benjamin C. Rislow

Small-angle, two-particle correlation functions have been measured for 36Ar+ 112,124Sn collisions at E/A = 61 MeV. Total momentum gated neutron-proton (np) and proton-proton (pp) correlations are stronger for the 124Sn-target. Some of the…

Primordial Big-Bang Nucleosynthesis (BBN) tightly constrains the existence of any additional relativistic degrees of freedom at that epoch. However a large asymmetry in electron neutrino number shifts the chemical equilibrium between the…

High Energy Physics - Phenomenology · Physics 2009-10-31 J. March-Russell , H. Murayama , A. Riotto

In this updated and expanded version of our delayed Comment we show that the np backward cross section, as presented by the Uppsala group, is seriously flawed (more than 25 sd.). The main reason is the incorrect normalization of the data.…

Nuclear Theory · Physics 2009-10-31 M. C. M. Rentmeester , R. A. M. Klomp , J. J. de Swart

The neutron-neutron and proton-proton pairing correlations have long been recognised to be the dominant many-body correlation beyond the nuclear mean field since the introduction of pairing mechanism by Bohr, Mottelson and Pines nearly 60…

Nuclear Theory · Physics 2016-03-28 Chong Qi , R. Wyss

Based upon the Bonn meson-exchange model for the nucleon-nucleon ($NN$) interaction, we study systematically the charge-symmetry-breaking (CSB) of the $NN$ interaction due to nucleon mass splitting. Particular attention is payed to CSB…

Nuclear Theory · Physics 2008-11-26 G. Q. Li , R. Machleidt

We compute isospin-violating meson-nucleon coupling constants and their consequent charge-symmetry-breaking nucleon-nucleon potentials. The couplings result from evaluating matrix elements of quark currents between nucleon states in a…

Nuclear Theory · Physics 2008-11-26 S. Gardner , C. J. Horowitz , J. Piekarewicz

Excitation functions of the spin correlation coefficients A_{NN}(p_{lab},theta_{c.m.}), A_{SS}(p_{lab},theta_{c.m.}), and A_{SL}(p_{lab},theta_{c.m.}) have been measured with the polarized proton beam of the Cooler Synchrotron COSY and an…

Nuclear Experiment · Physics 2009-11-10 F. Bauer

We have measured the neutron spin asymmetry $A_1^n$ with high precision at three kinematics in the deep inelastic region at $x=0.33$, 0.47 and 0.60, and $Q^2=2.7$, 3.5 and 4.8 (GeV/c)$^2$, respectively. Our results unambiguously show, for…

Nuclear Experiment · Physics 2008-11-26 X. Zheng

The $pp\to pp\gamma$ bremsstrahlung cross section is calculated within the method of coordinate space representation. It is shown that in the beam energy range of 350--450~MeV a deep attractive NN-potential with forbidden states (Moscow…

Nuclear Theory · Physics 2009-10-30 N. A. Khokhlov , V. A. Knyr , V. G. Neudatchin , Andrey M. Shirokov

We present detailed arguments and calculations in support of our recent proposal to identify the axion arising in the solution of the strong CP problem with the Majoron, the (pseudo-)Goldstone boson of spontaneously broken lepton number…

High Energy Physics - Phenomenology · Physics 2015-06-04 Adam Latosinski , Krzysztof A. Meissner , Hermann Nicolai

In this article, we study the implications of the coupling between Axion-Like-Particles (ALPs) and Leptons to cosmology, in particular, the Big Bang Nucleosynthesis (BBN). We show that the BBN, through the constraint on the effective number…

High Energy Physics - Phenomenology · Physics 2020-11-11 Diptimoy Ghosh , Divya Sachdeva

We study the phenomenological consequences of maximal and near-maximal mixing of the electron neutrino with other ($x$=tau and/or muon) neutrinos. We describe the deviations from maximal mixing in terms of a parameter…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. C. Gonzalez-Garcia , C. Peña-Garay , Y. Nir , A. Yu. Smirnov

The proton-proton bremsstrahlung is investigated within a coupled-channel model with the $\Delta$ degree of freedom. The model is consistent with the $NN$ scattering up to 1 GeV and the $\gamma N\Delta$ vertex determined in the study of…

Nuclear Theory · Physics 2009-09-25 F. de Jong , K. Nakayama , T. -S. H. Lee

(Abridged) Neutrino interactions beyond the standard model may affect the cosmological evolution and can be constrained through observations. We consider the possibility that neutrinos possess secret scalar or pseudoscalar interactions…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-15 Francesco Forastieri , Massimiliano Lattanzi , Paolo Natoli

A review is made of constraints on the nuclear symmetry energy parameters arising from nuclear binding energy measurements, theoretical chiral effective field predictions of neutron matter properties, the unitary gas conjecture, and…

Nuclear Theory · Physics 2023-01-11 James M. Lattimer
‹ Prev 1 2 3 10 Next ›