Search results for "Elementary Particle"
showing 10 items of 659 documents
C12(γ,p)11B cross section from 80 to 157 MeV
1995
The $^{12}\mathrm{C}$(\ensuremath{\gamma},p${)}^{11}$B differential cross section has been measured over proton angles ranging from 58\ifmmode^\circ\else\textdegree\fi{} to 128\ifmmode^\circ\else\textdegree\fi{}, using tagged photons of energy 80--157 MeV, for low-lying regions of residual excitation energy in $^{11}\mathrm{B}$. The data have been compared with four different types of calculation. It is shown that scaling of the cross section with momentum mismatch occurs for both the ground-state and excited-state data.
Hybridization ofsd- andfp-shell proton orbitals in the systemS36+37Cl
1993
Experimental and theoretical evidence is presented that the proton exchange is strongly enhanced by a mixing of single-particle configurations in $^{37}\mathrm{Cl}$ (in the system $^{36}\mathrm{S}$${+}^{37}$Cl, which is shown to be the clearest example of hybridization in nuclear physics. The experimental data on elastic and inelastic transfer are only reproduced if the complete set of single-particle states (${\mathit{d}}_{3/2}$,${\mathit{s}}_{1/2}$,${\mathit{f}}_{7/2}$,${\mathit{p}}_{3/2}$,${\mathit{f}}_{5/2}$, and ${\mathit{p}}_{1/2}$) is included in a coupled-reaction-channel calculation. The strong enhancement is explained by the hybridization of orbits of different parity. In a two-ce…
Pion interaction with the trinucleon up to the eta production threshold
1993
Pion elastic, charge exchange scattering and induced eta production on the trinucleon systems are investigated in a coupled-channels approach in momentum space with Fadeev wave functions. The channel $\pi N \rightarrow \eta N$ is included using an isobar model with S-, P-, and D-wave resonances. While the coherent reactions like $^3$He($\pi,\pi)^3$He can be reasonably well reproduced up to $T_{\pi}$=500 MeV, large discrepancies appear for the incoherent processes, $^3$He($\pi^-,\pi^0)^3$H and $^3$He($\pi^-,\eta)^3$H at backward angles and energies above $\Delta$-resonance. In the forward direction the $(\pi,\eta)$ calculations underestimate the experimental measurements very close to thresh…
Exploring the 10Li structure by the d(9Li,p)10Li transfer reaction
2015
The 9Li + 2H reaction has been investigated at 11 AMeV incident energy at the ISAC II facility (TRIUMF). In the present paper we focus on the one-neutron transfer channel, which potentially holds spectroscopic information on the unbound nucleus 10Li. The TUDA setup has been used in order to detect and identify the outgoing 9Li at forward angles and the recoil protons at backward angles. This setup allows to study the 10Li emitted in the crucial region at forward angles in the center of mass.
The d(9Li,p)10Li reaction as a tool to explore the 10Li structure
2015
The ground and low-lying states of the unbound nucleus 10Li were populated by the 9Li + 2H → 10Li + 1H reaction at 11 AMeV incident energy at the ISAC II facility (TRIUMF). In the experimental setup, the outgoing 9Li at forward angles and the recoil protons at backward angles were detected and identified. This setup allows to study the 10Li emitted in the crucial region at forward angles in the centre of mass.
Gamow-Teller unit cross sections for (t,He3) and (He3,t) reactions
2011
The proportionality between differential cross sections at vanishing linear momentum transfer and Gamow-Teller transition strength, expressed in terms of the unit cross section (${\mathrm{\ensuremath{\sigma}\ifmmode \hat{}\else \^{}\fi{}}}_{\mathit{GT}}$), was studied as a function of target mass number for ($t$,$^{3}\mathrm{He}$) and ($^{3}\mathrm{He}$,$t$) reactions at $115A$ MeV and $140A$ MeV, respectively. Existing ($^{3}\mathrm{He}$,$t$) and ($t$,$^{3}\mathrm{He}$) data on targets with mass number $12\ensuremath{\leqslant}A\ensuremath{\leqslant}120$ were complemented with new and reevaluated ($t$,$^{3}\mathrm{He}$) data on proton, deuteron, $^{6}\mathrm{Li}$, and $^{12}\mathrm{C}$ tar…
Suppression of away-side jet fragments with respect to the reaction plane in Au + Au collisions atsNN=200GeV
2011
Pair correlations between large transverse momentum neutral pion triggers (p(T) = 4-7 GeV/c) and charged hadron partners (p(T) = 3-7 GeV/c) in central (0%-20%) and midcentral (20%-60%) Au + Au collisions at root s(NN) = 200 GeV are presented as a function of trigger orientation with respect to the reaction plane. The particles are at larger momentum than where jet shape modifications have been observed, and the correlations are sensitive to the energy loss of partons traveling through hot densematter. An out-of-plane trigger particle produces only 26 +/- 20% of the away-side pairs that are observed opposite of an in-plane trigger particle for midcentral (20%-60%) collisions. In contrast, ne…
Pathlength dependence of energy loss within in-medium showers
2010
Studying the pathlength dependence of high P_T hadron suppression in heavy-ion collisions by measuring the dependence of hard hadron production on the angle phi with the reaction plane in non-central collisions has so far been one of the most successful tools in constraining the microscopical picture of leading parton energy loss. With the imminent start of the LHC heavy-ion program and the possibility of full jet reconstruction, the focus has shifted to models which are capable of simulating full in-medium parton showers rather than tracing the leading parton only. Yet, on the level of single inclusive hadron observables, such shower models need to reproduce the findings of leading parton …
Can relativistic pionic stripping explain (p,π+) reactions?
1978
The relativistic pionic stripping formalism is used to study pion production data on $^{12}\mathrm{C}$ and $^{40}\mathrm{Ca}$ in order to determine the appropriate form of the pion-nucleon vertex and to determine whether pionic stripping is the dominant mechanism for pion production.
Inclusive eta photoproduction in nuclei.
1993
A local model for the nuclear medium modifications to the photoproduction of \ensuremath{\eta} mesons through the ${\mathit{N}}^{\mathrm{*}}$(1535) resonance is applied to the study of the inclusive reaction in medium and heavy nuclei. The use of effective Lagrangians and many body quantum theory allows one to incorporate the nuclear decay channels of the ${\mathit{N}}^{\mathrm{*}}$ involving a pair of nucleons and Fermi sea effects. Also the \ensuremath{\eta}N final state interaction is considered, taking into account the nuclear renormalization of the \ensuremath{\eta}N scattering cross section, and assuming a classical propagation between collisions. The results show a depletion and broa…