Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · nucl-ex/0409005

The Quasielastic 3He(e,e'p)d Reaction at Q^2 = 1.5 GeV^2 for Recoil Momenta up to 1 GeV/c

M. M. Rvachev
View original source ↗Read source document ↗Export metadata ↓

Abstract

We have studied the quasielastic 3He(e,e'p)d reaction in perpendicular coplanar kinematics, with the energy and momentum transferred by the electron fixed at 840 MeV and 1502 MeV/c, respectively. The 3He(e,e'p)d cross section was measured for missing momenta up to 1000 MeV/c, while the A_TL asymmetry was extracted for missing momenta up to 660 MeV/c. For missing momenta up to 150 MeV/c, the measured cross section is described well by calculations that use a variational ground-state wave function of the 3He nucleus derived from a potential that includes three-body forces. For missing momenta from 150 to 750 MeV/c, strong final-state interaction effects are observed. Near 1000 MeV/c, the experimental cross section is more than an order of magnitude larger than predicted by available theories. The A_TL asymmetry displays characteristic features of broken factorization, and is described reasonably well by available models.

Explore related subjects

nucl-ex

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M. M. Rvachev. 2005-01-20. The Quasielastic 3He(e,e'p)d Reaction at Q^2 = 1.5 GeV^2 for Recoil Momenta up to 1 GeV/c. https://doi.org/10.1103/physrevlett.94.192302

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Centrality dependence of charged-particle pseudorapidity density at midrapidity in Pb-Pb collisions at $\mathbf{\sqrt{\textit{s}_{\rm NN}} = 5.36}$ TeV

The ALICE Collaboration reports its first LHC Run 3 measurements of charged-particle pseudorapidity density at midrapidity in Pb-Pb collisions at a centre-of-mass energy per nucleon pair of $\sqrt{s_{\mathrm{NN}}}=5.36$ TeV. Particle multiplicity in high-energy collisions characterises the system geometry, constrains particle-production mechanisms, and is used to estimate initial energy density. Multiplicity also acts as a reference for subsequent measurements as a function of centrality. In this letter, for the first time, charged particles are reconstructed using the upgraded ALICE Inner Tracking System and Time Projection Chamber, while the collision centrality is determined by measuring charged-particle multiplicities with the Fast Interaction Trigger system. Pseudorapidity density, ${\rm d}N_{\rm ch}/{\rm d}η$, is presented, averaged over events, for various centrality classes. Results are shown as a function of pseudorapidity and the average number of participating nucleons ($\langle N_{\mathrm{part}}\rangle$) in the collision. The average charged-particle pseudorapidity density ($\langle {\rm d}N_{\rm ch}/{\rm d}η\rangle$) at midrapidity ($|η|<0.5$) is 2010 $\pm$ 53 for the 5% most central collisions. The value of $\langle {\rm d}N_{\rm ch}/{\rm d}η\rangle$ normalised to $\langle N_{\mathrm{part}}\rangle/2$ as a function of $\sqrt{s_{\mathrm{NN}}}$ follows the trend established in previous measurements in heavy-ion collisions. Theoretical models based on mechanisms for particle production in nuclear collisions that involve the formation of quark-gluon plasma medium and models based on individual nucleon-nucleon interactions are compared to the data.

nucl-ex↗
arXiv2026

Exploring the origin of D$^0$ meson elliptic flow in PbPb collisions at $\sqrt{s_\mathrm{NN}}$ = 5.02 TeV using event shape engineering

The influence of the initial-state geometry on the elliptic flow of prompt D$^0$ mesons in high-energy heavy ion collisions is explored. A lead-lead (PbPb) data sample at a center-of-mass energy per nucleon pair of 5.02 TeV and with an integrated luminosity of 0.607 nb$^{-1}$ was collected in 2018 with the CMS detector at the CERN LHC. Based on these data, an event-shape engineering technique is used to isolate collisions with similar geometrical properties. An asymmetry parameter, $q_2$, is first determined from the distribution of transverse energy in the forward region of the detector. This parameter is shown to be linearly correlated with the elliptic anisotropy of inclusive charged particles measured near mid-rapidity, as characterized by the second-order Fourier coefficients, $v_2$. Taking the charged particle $v_2$ coefficients as proxies for the initial-state eccentricity, the correlation of D$^0$ meson $v_2$ values near mid-rapidity with those of inclusive charged particles is then studied. For D$^0$ mesons with transverse momenta in the range of 2$-$30 GeV and for different degrees of collision overlap, the $v_2$ values are found strongly correlated with those for charged particles when selected based on similar $q_2$ intervals. This correlation suggests that the initial-state geometry substantially impacts the development of charm-hadron flow in heavy ion collisions. A model calculation that explores the thermalization and collective motion of D$^0$ mesons and charged particles is compared to the experimental results.

nucl-ex↗
arXiv2026

Evidence for sequential $Υ$(nS) suppression in light ion collisions

Bound states of heavy quark-antiquark pairs, known as quarkonia, have long been regarded as particularly sensitive probes of the quark-gluon plasma (QGP). Comparing quarkonium yields in collisions of heavy nuclei, such as gold or lead, with a proton-proton (pp) reference reveals a characteristic pattern of sequential suppression, in which weakly-bound excited states are more strongly suppressed than the ground states. We report the first measurements of the three lowest mass $\mathrm{S}$-wave vector bottomonium resonances, the ground state $Υ$(1S) and the excited states $Υ$(2S) and $Υ$(3S), in oxygen-oxygen collisions at a center-of-mass energy per nucleon pair of $\sqrt{s_\mathrm{NN}}$ = 5.36 TeV. Measurements of the yields of the $Υ$(1S) and $Υ$(2S) resonances in neon-neon collisions, at the same $\sqrt{s_\mathrm{NN}}$, are also presented. The $Υ$(2S)/$Υ$(1S) ratio is found to be significantly below the measured pp reference value, and the $Υ$(3S)/$Υ$(1S) ratio shows an even larger reduction. The significance of the relative $Υ$(3S) to $Υ$(2S) suppression exceeds three standard deviations. These results provide evidence for the sequential suppression of $Υ$(nS) states in light ion collisions, similar to observations made in lead-lead and gold-gold collisions, generally attributed to the presence of a QGP medium.

nucl-ex↗