Search results for "baryon"
showing 10 items of 759 documents
Exact relativistic beta decay endpoint spectrum
2007
5 pages, 3 figures.-- PACS nrs.: 14.60.Pq; 13.30.-a; 23.40.-s; 23.40.Bw.-- ISI Article Identifier: 000250620900070.-- ArXiv pre-print available at: http://arxiv.org/abs/0706.0897
Future Physics Programme of BESIII
2020
There has recently been a dramatic renewal of interest in the subjects of hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like $XYZ$ states at BESIII and $B$ factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related $X(1835)$ meson state at BESIII, as well as the threshold measurements of charm mesons and charm baryons. We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESIII over the remaining lifetime of BEPCII operation. This survey will help in the optimization of the data-taking pla…
Meson and baryon resonances
2009
6 pages, 1 table.-- PACS nrs.: 13.75.Lb, 14.40.Cs, 12.40.Vv, 12.40.Yx.-- Talk at the 2008 International Conference on Particles And Nuclei (PANIC08, Nov 9-14, 2008, Eilat, Israel).
Flavored CP asymmetries for type II seesaw leptogenesis
2013
A novel contribution to the leptonic CP asymmetries in type II seesaw leptogenesis scenarios is obtained for the cases in which flavor effects are relevant for the dynamics of leptogenesis. In the so-called flavored leptogenesis regime, the interference between the tree-level amplitude of the scalar triplet decaying into two leptons and the one-loop wave function correction with leptons in the loop, leads to a new nonvanishing CP asymmetry contribution. The latter conserves total lepton number but violates lepton flavor. Cases in which this novel contribution may be dominant in the generation of the baryon asymmetry are briefly discussed.
First measurement of the polarization observable E and helicity-dependent cross sections in single π 0 photoproduction from quasi-free nucleons
2017
The double-polarization observable $E$ and the helicity-dependent cross sections $\sigma_{1/2}$ and $\sigma_{3/2}$ have been measured for the first time for single $\pi^{0}$ photoproduction from protons and neutrons bound in the deuteron at the electron accelerator facility MAMI in Mainz, Germany. The experiment used a circularly polarized photon beam and a longitudinally polarized deuterated butanol target. The reaction products, recoil nucleons and decay photons from the $\pi^0$ meson were detected with the Crystal Ball and TAPS electromagnetic calorimeters. Effects from nuclear Fermi motion were removed by a kinematic reconstruction of the $\pi^{0}N$ final state. A comparison to data mea…
Λc+ production in Pb–Pb collisions at √sNN = 5.02 TeV
2019
A measurement of the production of prompt Λc+ baryons in Pb–Pb collisions at √sNN = 5.02 TeV with the ALICE detector at the LHC is reported. The Λc+ and Λ‾c− were reconstructed at midrapidity (|y|<0.5) via the hadronic decay channel Λc+ → pKS0 (and charge conjugate) in the transverse momentum and centrality intervals 6<pT <12 GeV/c and 0–80%. The Λc+/D0 ratio, which is sensitive to the charm quark hadronisation mechanisms in the medium, is measured and found to be larger than the ratio measured in minimum-bias pp collisions at √s = 7 TeV and in p–Pb collisions at √sNN = 5.02 TeV. In particular, the values in p–Pb and Pb–Pb collisions differ by about two standard deviations of the combined s…
New experimental molecular stopping cross section data of Al2O3, for heavy ions
2014
Abstract Molecular stopping cross section data of Al2O3, for heavy ions of 12C, 16O, 28Si, 35Cl, 79Br within the energy range of 0.01–1.0 MeV/nucleon were measured. Both direct transmission and bulk analysis methods were applied. Stopping cross sections were calculated both with the SRIM and MSTAR codes. Evaluation and intercomparison of the new data with the calculated and previously measured ones are reported in this paper.
Measurements of Sigma(+) and Sigma(-) time-like electromagnetic form factors for center-of-mass energies from 2.3864 to 3.0200 GeV
2021
Physics letters / B 814, 136110 (2021). doi:10.1016/j.physletb.2021.136110
Suppression of Λ(1520) resonance production in central Pb-Pb collisions at √sNN = 2.76 TeV
2019
The production yield of the Λ(1520) baryon resonance is measured at midrapidity in Pb-Pb collisions at √sNN = 2.76 TeV with the ALICE detector at the Large Hadron Collider (LHC). The measurement is performed in the Λ(1520)→ pK− (and charge conjugate) hadronic decay channel as a function of the transverse momentum (pT) and collision centrality. The ratio of the pT-integrated production of Λ(1520) baryons relative to Λ baryons in central collisions is suppressed by about a factor of 2 with respect to peripheral collisions. This is the first observation of the suppression of a baryonic resonance at the LHC and the first 3σ evidence of Λ(1520) suppression within a single collision system. The m…
Observation of the baryonic decayB¯0→Λc+p¯K−K+
2015
We report the observation of the baryonic decay B^0 → Λ^+_c pK^−K^+ using a data sample of 471×10^6 BB pairs produced in e^+e^− annihilations at √s = 10.58 GeV. This data sample was recorded with the BABAR detector at the PEP-II storage ring at SLAC. We find B(B^0 → Λ^+_c pK^−K^+)=(2.5±0.4_((stat))±0.2_((syst))± 0.6_(B(Λ^+_c)))×10^(−5), where the uncertainties are statistical, systematic, and due to the uncertainty of the Λ^+_c →p K^−π^+ branching fraction, respectively. The result has a significance corresponding to 5.0 standard deviations, including all uncertainties. For the resonant decay B^0 → Λ^+_c pϕ, we determine the upper limit B(B^0 → Λ^+_c pϕ) <1.2 × 10^(−5) at 90% confidence le…