相关论文: Charge Symmetry Breaking in the n p --> d pi^0 rea…
The basic facts of charge symmetry breaking (CSB) phenomena are reviewed. The relevance of CSB to parity-violating electron-proton scattering experiments that seek to extract strange elastic form factors is discussed. Experimentalists have…
The photon asymmetry in the reaction p(\vec{\gamma},\pi^{0})p close to threshold has been measured for the first time with the photon spectrometer TAPS using linearly polarized photons from the tagged-photon facility at the Mainz Microtron…
We compute nonanalytical pion-loop corrections to baryon masses in a combined expansion in chiral symmetry breaking and 1/N_c, where N_c is the number of colors. Specifically, we compute flavor-27 baryon mass splittings at leading order in…
A surprisingly large charge symmetry violation of the sea quarks in the nucleon has been proposed in a recent article by Boros et al. as an explanation of the discrepancy between neutrino (CCFR) and muon (NMC) nucleon structure function…
Heavy baryon chiral perturbation theory ($\chi$PT), where the $\Delta$ resonance is included, is used in order to examine the axial charged-current component of the weak interaction process at low neutrino energies. At leading chiral order…
We reexamine the dynamical generation of mass for fermions charged under various Lie groups with equal charge and mass at a high Grand Unification scale, extending the Renormalization Group Equations in the perturbative regime to two-loops…
The latest measurements of the asymmetry in the angular distributions of the $t\bar{t}$ events are reviewed. The measurements of the forward-backward asymmetry $A_{FB}$ in the $p\bar{p}$ 1.98 TeV collision at the Tevatron show some tension…
This series of three lectures covers (a) a basic introduction to symmetry breaking in general and chiral symmetry breaking in QCD, (b) an overview of the present status of lattice data and the knowlegde that we have at finite temperature…
We study the reaction $\pi^\pm p \to \pi^\pm \pi^+ n$ and $\pi^- p \to \pi^0 \pi^0 n$ in heavy-baryon chiral perturbation theory of chiral order three from threshold up to pion laboratory kinetic energies of 400 MeV. We find that the…
Some recent experimental and theoretical work on 1) charge symmetry-breaking, 2) parity non-conservation, and 3) searches for breaking of time reversal invariance are reviewed. The examples illustrate the uses of symmetry to learn about…
The recently measured charge asymmetry of like-sign dimuon events by the D0 collaboration at Tevatron shows the 3.9 \sigma\ deviation from the standard model prediction. In order to solve this mismatch, we investigate the right-handed…
Charge symmetry breaking (CSB) is particularly strong in the A=4 mirror hypernuclei $_{\Lambda}^4$H--$_{\Lambda}^4$He. Recent four-body no-core shell model calculations that confront this CSB by introducing $\Lambda$-$\Sigma^0$ mixing to…
The D0 collaboration has announced the observation of the like-sign dimuon charge asymmetry since 2010, which has more than 3\sigma deviation from the Standard Model prediction. One of the promising explanation is considering the existence…
The impact of chiral symmetry on nuclear physics is discussed in the context of recent advances in the few-nucleon systems and of dimensional power counting. The tractability of few-nucleon calculations, illustrated by very recent solutions…
The study of charge symmetry violation in nuclear physics is a potentially enormous subject. Through a few topical examples we aim to show that it is not a subject of peripheral interest but rather goes to the heart of our understanding of…
The charge asymmetry has been measured using $19,039~W$ decays recorded by the CDF detector during the 1992-93 run of the Tevatron Collider. The asymmetry is sensitive to the ratio of $d$ and $u$ quark distributions to $x<0.01$ at $Q^2…
We present the anomalous cross section for baryon number violation in the standard model from the perturbation of large-order behavior of forward scattering amplitudes to the order $\left(\epsilon /n\right)^{8/3} \ln\left(\epsilon…
A review on the requirements of chiral symmetry on effective quark models is presented. The connection between the pion Salpeter amplitude and the mass gap equation is discussed. Hadronic scattering, notably, $\pi\pi$ scattering is…
Measured values of the differential cross sections for pion-nucleon charge exchange, pi- p --> pi0 n, are presented for pi- momenta of 103, 112, 120, 130, 139, 152, and 178 MeV/c. Complete angular distributions were obtained by using the…
We study Lambda_c/Lambda}_c-bar production asymmetries in pp and pi- p collisions using a recently proposed two component model. The model includes heavy baryon production by the usual mechanism of parton fusion and fragmentation plus…