Data obtained by the associated production of A hypernuclei through the (tr+, K+) reaction are pr... more Data obtained by the associated production of A hypernuclei through the (tr+, K+) reaction are presented for a wide range of mass numbers. The special features which make this reaction useful are pointed out. The reaction is shown to be an excellent probe of A single-particle states, as demonstrated by the excitation of deeply bound states which are interpreted as the weak coupling of a A to neutronhole states of the core. The A binding energies and ground-state production cross sections for ABe, 'AC, 'AO,-'ASi, ACa, 'A'v, and AY are presented.
Using a silicon-microstrip detector array to identify secondary vertices, we have observed b-t JJ... more Using a silicon-microstrip detector array to identify secondary vertices, we have observed b-t JJ$-) p +p decays in 800 GeV/c proton-gold interactions. The doubly-differential cross section for J/$ mesons originating from b-quark decays, assuming linear nuclear dependence, is d'o/dzF dp$ = 107 6 28 f 19 pb/(GeV/c)a/nucleon at ZF = 0.05 and pi = 1 GeV/c. This measurement is compared to next-to-leading-order QCD predictions. The integrated b-quark production cross section, obtained by extrapolation over all IF and pr, is o(pN + b5 + X) = 5.7 * 1.5 5 1.3 nb/nucleon.
The inverse tritium beta decay (ITBD) reaction, νe+ 3 H → e − + 3 He, is a promising experimental... more The inverse tritium beta decay (ITBD) reaction, νe+ 3 H → e − + 3 He, is a promising experimental tool for observing relic neutrinos created in the early Universe. This reaction has been selected by the PTOLEMY experiment for the search of relic neutrinos. Despite its potential, the ITBD reaction induced by any sources of neutrinos has yet to be observed. We show that an intense 51 Cr radioactive neutrino source is suitable for observing the ITBD reaction for the first time. As the Sun is another source of intense electron neutrinos, we also examine the ITBD reaction rate from solar neutrinos. Based on our recent studies on the evolution of the helicity of relic neutrinos, we further present the ITBD rate for capturing relic neutrinos as a function of neutrino mass hierarchy, the Dirac versus Majorana nature of neutrino, and the mass of the lightest neutrino.
Proceedings of the 24th International Spin Symposium (SPIN2021)
Primordial neutrinos provide information on the Universe at a very early stage, roughly one secon... more Primordial neutrinos provide information on the Universe at a very early stage, roughly one second after the big bang. Their detection would have a major impact on our knowledge in cosmology and neutrino physics. The most promising experimental technique for detecting these extremely low energy primordial neutrinos involves their capture on a radioactive tritium target. The capture rate depends on certain yet unknown neutrino properties, including their masses and their Dirac or Majorana nature. We show that the capture rate also depends on the helicity of primordial neutrinos, which evolves as neutrinos propagate through the cosmic gravitational and magnetic fields. We predict the dependence of the capture rate on various properties of primordial neutrinos.
This rcprt WUE prepnrcd M an uccounl of work spmnorcd h: n. agency rlhtt Ilnikd Slates Governmcnl... more This rcprt WUE prepnrcd M an uccounl of work spmnorcd h: n. agency rlhtt Ilnikd Slates Governmcnl. Neilher lhe UniA Slules Govcrnnlenl nor any rngency lhe(u)f, nor tiny of Ihcir c,nployec.t makes any warrnnly, cxprcac or implied, or nnaumm any legal i:~bility or reqmnnihilily for Ihc accuracy, Comidclcncaa, or uscfolnecs of any informnlion, nppraius, proArcI, or proccw diaclrxd, or rcprcacnts (ha[ its ucc would nol inrringe priva[cly ownod igh:s. Rob. cnm herein 10 nny rn~ific cwmmwciul pruducl, prwxsc, or m-vim by mndc narcc, hadcmark, manurac[urcr, or o[herwiw dwn not nccec.wcrily conn[itule or imply itn enrior.umcni, r~mmendntion, or favorins hy Ihe Unilcd SIaIcs Govcrnmcn[ or any agctwy ih=rcof. The viewg and opinions of aulhorn caprcnd hcrcln do nol nwxcsarily stale or reflect !hoac of lhe (Jnilal Slnlcn (Jovcrnmenl or any qency thermf.
Dimuon production has been studied in a series of fixed-target experiments at Fermilab during the... more Dimuon production has been studied in a series of fixed-target experiments at Fermilab during the last two decades. Highlights from these experiments, together with recent results from the Fermilab E866 experiment, are presented. Future prospects for studying the parton distributions in the nucleons and nuclei using dimuon production are also discussed.
Abstract The energy dependence of nucleus-nucleus total cross sections (σNNT) has been investigat... more Abstract The energy dependence of nucleus-nucleus total cross sections (σNNT) has been investigated for p, d, 3He, α, and 12C on 12C. The σT data exhibit an even more pronounced drop at medium energies than seen in the nucleus-nucleus σR data. Microscopic calculations based on the optical limit of the Glauber theory provide a good description of the available σT data.
... R. Childers, CW Darden, D. Snod University of South Caroline, Colum F ass, JR Wilson aa, Sout... more ... R. Childers, CW Darden, D. Snod University of South Caroline, Colum F ass, JR Wilson aa, South Carolina YC Chen'sl, GC Kian 1 PK Teng' 'Institute of Ph sits, Academia uuca, Taipei, Taiwan Kr $1 zlnstitute of Physics, ational Cheng Kung Univ., Toinon, Taiwan Abstract ...
Annual Review of Nuclear and Particle Science, 1999
▪   We review the production of high-mass lepton pairs in fixed-target experiments, including bot... more ▪   We review the production of high-mass lepton pairs in fixed-target experiments, including both Drell-Yan (DY) and heavy quarkonium production [J/ψ, ψ′, ϒ(1S), ϒ(2S), and ϒ(3S)]. In recent years, DY data have become standard input to the determination of parton density distributions. DY data have recently yielded the first measurement of the x dependence of the [Formula: see text], asymmetry of the proton. Similar to the observations in deeply inelastic scattering, precision measurements of the nuclear dependence of the proton-induced DY process exhibit shadowing at small target momentum fraction, x2. There is, however, no evidence of enhanced DY production from nuclear targets. Mean transverse momenta of DY pairs are observed to increase with target mass. These data, analyzed within a new theoretical framework, provide an estimation of the energy loss of fast quarks in nuclear matter. In contrast to the DY process, there are large nuclear effects in the production of all quarkon...
Recent analysis of proton and deuteron deep-inelastic scattering data have suggested that the ext... more Recent analysis of proton and deuteron deep-inelastic scattering data have suggested that the extracted d/u quark distribution ratio at large x may be significantly larger than previously believed, if the data are corrected for nuclear binding effects in the deuteron. We examine the sensitivity to the large-x d/u ratio of lepton asymmetries from W-boson production in pp and pp collisions at large rapidity, which do not suffer from nuclear contamination.
We present a new analysis to extract pion's parton distribution functions (PDFs) in the framework... more We present a new analysis to extract pion's parton distribution functions (PDFs) in the framework of the statistical model. Starting from the statistical model framework first developed for the spin-1/2 nucleon, we apply appropriate modifications taking into account the spin-0 nature of pion and the isospin and charge-conjugation symmetry properties. This results in a significant reduction of the number of parameters compared to a recent work to extract pion's PDFs. Using π −-induced Drell-Yan data to determine the parameters of this statistical model approach, we show that a good description of these experimental data with Next-to-Leading order QCD calculations can be obtained. Good agreement between the calculations and the π + /π − Drell-Yan cross section ratio data, not included in the global fit, has confirmed the predictive power of these new pion PDFs.
Fusion reactions of the neighboring nuclei systems, i.e., ' C on "C, "N, ' 0, "0, and "F were ana... more Fusion reactions of the neighboring nuclei systems, i.e., ' C on "C, "N, ' 0, "0, and "F were analyzed. In. the low energy regions, it is pointed out that a commonly used parametrized form has various insufficiencies. Use of the four kinds of potentials, Woods-Saxon, single-folding, double-folding, and proximity potentials were examined, and all show a unique trend of gradually increasing radii among these systems. In the high energy regioris, decreasing cross sections towards higher incident energies cannot be explained in general by the staightforward yrast cut oA' treatments, although they are close in these light nuclei systems. If the partial waves are limited for those having the minima of their potential pockets inside the half density distance predicted by the proximity potential, the experimental data can be fitted. NUCLEAR REACTIONS Analyses of fusion reactions:~C +~C ,~C + 4N,~C +~Q,~C+~0,~C+ 9F; potential model using%oods-Saxon, single-folding, double-folding potentials: yrast cutoff, critical distance in the proximity potential.
We discuss the physics interest and the experimental feasibility for detecting high-mass dimuon p... more We discuss the physics interest and the experimental feasibility for detecting high-mass dimuon pairs using the planned 50-GeV Proton Synchrotron (PS) at the KEK/JHF and JAERI/NSP joint accelerator project. The Drell-Yan measurement of $p+d$ versus $p+p$ at 50 GeV will provide unique information on the flavor asymmetry of proton's up and down sea-quark distributions in the large-$x$ region. A study of the nuclear dependences of Drell-Yan cross sections can reveal the modification of antiquark distributions in nuclei. Furthermore, the effect of energy loss for fast partons traversing nuclear medium could also be sensitively measured. If polarized proton beam becomes available at the 50-GeV PS, unique information on the sea-quark polarization could be obtained. Study of heavy quarkonium production at the 50-GeV PS can set important constraints on the mechanism of vector meson productions. Using a prototype dimuon spectrometer, we have simulated the sensitivities for a variety of m...
Data obtained by the associated production of A hypernuclei through the (tr+, K+) reaction are pr... more Data obtained by the associated production of A hypernuclei through the (tr+, K+) reaction are presented for a wide range of mass numbers. The special features which make this reaction useful are pointed out. The reaction is shown to be an excellent probe of A single-particle states, as demonstrated by the excitation of deeply bound states which are interpreted as the weak coupling of a A to neutronhole states of the core. The A binding energies and ground-state production cross sections for ABe, 'AC, 'AO,-'ASi, ACa, 'A'v, and AY are presented.
Using a silicon-microstrip detector array to identify secondary vertices, we have observed b-t JJ... more Using a silicon-microstrip detector array to identify secondary vertices, we have observed b-t JJ$-) p +p decays in 800 GeV/c proton-gold interactions. The doubly-differential cross section for J/$ mesons originating from b-quark decays, assuming linear nuclear dependence, is d'o/dzF dp$ = 107 6 28 f 19 pb/(GeV/c)a/nucleon at ZF = 0.05 and pi = 1 GeV/c. This measurement is compared to next-to-leading-order QCD predictions. The integrated b-quark production cross section, obtained by extrapolation over all IF and pr, is o(pN + b5 + X) = 5.7 * 1.5 5 1.3 nb/nucleon.
The inverse tritium beta decay (ITBD) reaction, νe+ 3 H → e − + 3 He, is a promising experimental... more The inverse tritium beta decay (ITBD) reaction, νe+ 3 H → e − + 3 He, is a promising experimental tool for observing relic neutrinos created in the early Universe. This reaction has been selected by the PTOLEMY experiment for the search of relic neutrinos. Despite its potential, the ITBD reaction induced by any sources of neutrinos has yet to be observed. We show that an intense 51 Cr radioactive neutrino source is suitable for observing the ITBD reaction for the first time. As the Sun is another source of intense electron neutrinos, we also examine the ITBD reaction rate from solar neutrinos. Based on our recent studies on the evolution of the helicity of relic neutrinos, we further present the ITBD rate for capturing relic neutrinos as a function of neutrino mass hierarchy, the Dirac versus Majorana nature of neutrino, and the mass of the lightest neutrino.
Proceedings of the 24th International Spin Symposium (SPIN2021)
Primordial neutrinos provide information on the Universe at a very early stage, roughly one secon... more Primordial neutrinos provide information on the Universe at a very early stage, roughly one second after the big bang. Their detection would have a major impact on our knowledge in cosmology and neutrino physics. The most promising experimental technique for detecting these extremely low energy primordial neutrinos involves their capture on a radioactive tritium target. The capture rate depends on certain yet unknown neutrino properties, including their masses and their Dirac or Majorana nature. We show that the capture rate also depends on the helicity of primordial neutrinos, which evolves as neutrinos propagate through the cosmic gravitational and magnetic fields. We predict the dependence of the capture rate on various properties of primordial neutrinos.
This rcprt WUE prepnrcd M an uccounl of work spmnorcd h: n. agency rlhtt Ilnikd Slates Governmcnl... more This rcprt WUE prepnrcd M an uccounl of work spmnorcd h: n. agency rlhtt Ilnikd Slates Governmcnl. Neilher lhe UniA Slules Govcrnnlenl nor any rngency lhe(u)f, nor tiny of Ihcir c,nployec.t makes any warrnnly, cxprcac or implied, or nnaumm any legal i:~bility or reqmnnihilily for Ihc accuracy, Comidclcncaa, or uscfolnecs of any informnlion, nppraius, proArcI, or proccw diaclrxd, or rcprcacnts (ha[ its ucc would nol inrringe priva[cly ownod igh:s. Rob. cnm herein 10 nny rn~ific cwmmwciul pruducl, prwxsc, or m-vim by mndc narcc, hadcmark, manurac[urcr, or o[herwiw dwn not nccec.wcrily conn[itule or imply itn enrior.umcni, r~mmendntion, or favorins hy Ihe Unilcd SIaIcs Govcrnmcn[ or any agctwy ih=rcof. The viewg and opinions of aulhorn caprcnd hcrcln do nol nwxcsarily stale or reflect !hoac of lhe (Jnilal Slnlcn (Jovcrnmenl or any qency thermf.
Dimuon production has been studied in a series of fixed-target experiments at Fermilab during the... more Dimuon production has been studied in a series of fixed-target experiments at Fermilab during the last two decades. Highlights from these experiments, together with recent results from the Fermilab E866 experiment, are presented. Future prospects for studying the parton distributions in the nucleons and nuclei using dimuon production are also discussed.
Abstract The energy dependence of nucleus-nucleus total cross sections (σNNT) has been investigat... more Abstract The energy dependence of nucleus-nucleus total cross sections (σNNT) has been investigated for p, d, 3He, α, and 12C on 12C. The σT data exhibit an even more pronounced drop at medium energies than seen in the nucleus-nucleus σR data. Microscopic calculations based on the optical limit of the Glauber theory provide a good description of the available σT data.
... R. Childers, CW Darden, D. Snod University of South Caroline, Colum F ass, JR Wilson aa, Sout... more ... R. Childers, CW Darden, D. Snod University of South Caroline, Colum F ass, JR Wilson aa, South Carolina YC Chen'sl, GC Kian 1 PK Teng' 'Institute of Ph sits, Academia uuca, Taipei, Taiwan Kr $1 zlnstitute of Physics, ational Cheng Kung Univ., Toinon, Taiwan Abstract ...
Annual Review of Nuclear and Particle Science, 1999
▪   We review the production of high-mass lepton pairs in fixed-target experiments, including bot... more ▪   We review the production of high-mass lepton pairs in fixed-target experiments, including both Drell-Yan (DY) and heavy quarkonium production [J/ψ, ψ′, ϒ(1S), ϒ(2S), and ϒ(3S)]. In recent years, DY data have become standard input to the determination of parton density distributions. DY data have recently yielded the first measurement of the x dependence of the [Formula: see text], asymmetry of the proton. Similar to the observations in deeply inelastic scattering, precision measurements of the nuclear dependence of the proton-induced DY process exhibit shadowing at small target momentum fraction, x2. There is, however, no evidence of enhanced DY production from nuclear targets. Mean transverse momenta of DY pairs are observed to increase with target mass. These data, analyzed within a new theoretical framework, provide an estimation of the energy loss of fast quarks in nuclear matter. In contrast to the DY process, there are large nuclear effects in the production of all quarkon...
Recent analysis of proton and deuteron deep-inelastic scattering data have suggested that the ext... more Recent analysis of proton and deuteron deep-inelastic scattering data have suggested that the extracted d/u quark distribution ratio at large x may be significantly larger than previously believed, if the data are corrected for nuclear binding effects in the deuteron. We examine the sensitivity to the large-x d/u ratio of lepton asymmetries from W-boson production in pp and pp collisions at large rapidity, which do not suffer from nuclear contamination.
We present a new analysis to extract pion's parton distribution functions (PDFs) in the framework... more We present a new analysis to extract pion's parton distribution functions (PDFs) in the framework of the statistical model. Starting from the statistical model framework first developed for the spin-1/2 nucleon, we apply appropriate modifications taking into account the spin-0 nature of pion and the isospin and charge-conjugation symmetry properties. This results in a significant reduction of the number of parameters compared to a recent work to extract pion's PDFs. Using π −-induced Drell-Yan data to determine the parameters of this statistical model approach, we show that a good description of these experimental data with Next-to-Leading order QCD calculations can be obtained. Good agreement between the calculations and the π + /π − Drell-Yan cross section ratio data, not included in the global fit, has confirmed the predictive power of these new pion PDFs.
Fusion reactions of the neighboring nuclei systems, i.e., ' C on "C, "N, ' 0, "0, and "F were ana... more Fusion reactions of the neighboring nuclei systems, i.e., ' C on "C, "N, ' 0, "0, and "F were analyzed. In. the low energy regions, it is pointed out that a commonly used parametrized form has various insufficiencies. Use of the four kinds of potentials, Woods-Saxon, single-folding, double-folding, and proximity potentials were examined, and all show a unique trend of gradually increasing radii among these systems. In the high energy regioris, decreasing cross sections towards higher incident energies cannot be explained in general by the staightforward yrast cut oA' treatments, although they are close in these light nuclei systems. If the partial waves are limited for those having the minima of their potential pockets inside the half density distance predicted by the proximity potential, the experimental data can be fitted. NUCLEAR REACTIONS Analyses of fusion reactions:~C +~C ,~C + 4N,~C +~Q,~C+~0,~C+ 9F; potential model using%oods-Saxon, single-folding, double-folding potentials: yrast cutoff, critical distance in the proximity potential.
We discuss the physics interest and the experimental feasibility for detecting high-mass dimuon p... more We discuss the physics interest and the experimental feasibility for detecting high-mass dimuon pairs using the planned 50-GeV Proton Synchrotron (PS) at the KEK/JHF and JAERI/NSP joint accelerator project. The Drell-Yan measurement of $p+d$ versus $p+p$ at 50 GeV will provide unique information on the flavor asymmetry of proton's up and down sea-quark distributions in the large-$x$ region. A study of the nuclear dependences of Drell-Yan cross sections can reveal the modification of antiquark distributions in nuclei. Furthermore, the effect of energy loss for fast partons traversing nuclear medium could also be sensitively measured. If polarized proton beam becomes available at the 50-GeV PS, unique information on the sea-quark polarization could be obtained. Study of heavy quarkonium production at the 50-GeV PS can set important constraints on the mechanism of vector meson productions. Using a prototype dimuon spectrometer, we have simulated the sensitivities for a variety of m...
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Papers by Jen-Chieh Peng