Production Of Antideuterons Research Articles

Search for the production of deuterons and antideuterons in e+e− annihilation at center-of-mass energies between 4.13 and 4.70 GeV

Using a data sample of e+e− collision data corresponding to an integrated luminosity of 19 fb−1 collected with the BESIII detector at the BEPCII collider, we search for the production of deuterons and antideuterons via e+e−→ppπ−d¯+c.c. for the first time at center-of-mass energies between 4.13 and 4.70 GeV. No significant signal is observed and the upper limit of the e+e−→ppπ−d¯+c.c. cross section is determined to be from 9.0 to 145 fb depending on the center-of-mass energy at the 90% confidence level. Published by the American Physical Society 2024

Multiplicity dependence of (anti-)deuteron production in pp collisions at [formula omitted

In this letter, the production of deuterons and anti-deuterons in pp collisions at s=7 TeV is studied as a function of the charged-particle multiplicity density at mid-rapidity with the ALICE detector at the LHC. Production yields are measured at mid-rapidity in five multiplicity classes and as a function of the deuteron transverse momentum (pT). The measurements are discussed in the context of hadron–coalescence models. The coalescence parameter B2, extracted from the measured spectra of (anti-)deuterons and primary (anti-)protons, exhibits no significant pT-dependence for pT<3GeV/c, in agreement with the expectations of a simple coalescence picture. At fixed transverse momentum per nucleon, the B2 parameter is found to decrease smoothly from low multiplicity pp to Pb–Pb collisions, in qualitative agreement with more elaborate coalescence models. The measured mean transverse momentum of (anti-)deuterons in pp is not reproduced by the Blast-Wave model calculations that simultaneously describe pion, kaon and proton spectra, in contrast to central Pb–Pb collisions. The ratio between the pT-integrated yield of deuterons to protons, d/p, is found to increase with the charged-particle multiplicity, as observed in inelastic pp collisions at different centre-of-mass energies. The d/p ratios are reported in a wide range, from the lowest to the highest multiplicity values measured in pp collisions at the LHC.

Constraining production models with light (anti-)nuclei measurements in small systems with ALICE at the LHC

The production of deuterons and anti-deuterons in pp collisions at s=7and13TeV has been studied as a function of charged-particle multiplicity using the ALICE detector at the LHC. The preliminary results are shown here, together with those obtained in heavy-ion collisions. They are presented by focusing the discussion on the comparison with expectations from hadron-coalescence models.

Antideuteron limits on decaying dark matter with a tuned formation model

We investigate the production of antideuterons from decaying dark matter, using gravitinos in supersymmetric models with trilinear R-parity violating (RPV) operators as an example. The model used for antideuteron formation is shown to induce large uncertainties in the predicted flux, comparable to uncertainties from cosmic-ray propagation models. We improve on the formation model by tuning hadronization and coalesence parameters in Monte Carlo simulations to better reproduce the hadron spectra relevant for antideuteron production. In light of current bounds on fluxes and future prospects from the AMS-II and GAPS experiments we set limits on RPV couplings as a function of the gravitino mass.

Antideuteron and deuteron production in midcentral Pb+Pb collisions at 158AGeV

Production of deuterons and antideuterons was studied by the NA49 experiment in the 23.5% most central Pb+Pb collisions at the top SPS energy of $\sqrt{s_{NN}}$=17.3 GeV. Invariant yields for $\bar{d}$ and $d$ were measured as a function of centrality in the center-of-mass rapidity range $-1.2<y<-0.6$. Results for $\bar{d}(d)$ together with previously published $\bar{p}(p)$ measurements are discussed in the context of the coalescence model. The coalescence parameters $B_2$ were deduced as a function of transverse momentum $p_t$ and collision centrality.

Source dynamics from deuteron and anti-deuteron measurements in Au+Au collisions at GeV in PHENIX

The production of deuterons and anti-deuterons in the transverse momentum range 1.1 <pT< 5.0 GeV/c at mid-rapidity in Au+Au collisions at GeV has been studied by PHENIX for six different centralities. The coalescence of neutrons and protons into deuterons as a function of pT and Npart has been studied. The large RCP of deuterons at intermediate pT is consistent with neutron production having similar centrality dependence to that of protons.

Deuteron and anti-deuteron production in e+e− collisions at the Z resonance

Deuteron and anti-deuteron production in Z decays has been observed in the ALEPH experiment at LEP. The production rate of anti-deuterons is measured to be 5.9+-1.8+-0.5 10^-6 per hadronic Z decay in the anti-deuteron momentum range 0.62 to 1.03 GeV/c. The coalescence parameter B_2, which characterizes the likelihood of anti-deuteron production, is measured to be 0.0033+-0.0013 GeV^2 in Z dedays. These measurements indicate that the production of anti-deuterons is suppressed in e+e- collisions compared to pp and photoproduction collisions.

Deuteron and Antideuteron Production inAu+AuCollisions atsNN=200 GeV

The production of deuterons and antideuterons in the transverse momentum range 1.1<p(T)<4.3 GeV/c at midrapidity in Au+Au collisions at square root of s(NN)=200 GeV has been studied by the PHENIX experiment at RHIC. A coalescence analysis, comparing the deuteron and antideuteron spectra with that of proton and antiproton, has been performed. The coalescence probability is equal for both deuterons and antideuterons and it increases as a function of p(T), which is consistent with an expanding collision zone. Comparing (anti)proton yields, p /p=0.73+/-0.01, with (anti)deuteron yields, d /d=0.47+/-0.03, we estimate that n /n=0.64+/-0.04. The nucleon phase space density is estimated from the coalescence measurement.

Production of neutral pions and antideuterons, and observation of proton-antiproton asymmetry in the photon hemisphere at HERA

Electron or positron beams at HERA provide a source of quasi-real photons which, after collision with a proton, convert into hadron-rich photon “remnants”. Here, preliminary results are presented on production of neutral pions and antideuterons in the photon hemisphere and on the asymmetry observed in the production of protons and antiprotons.

Antiproton production and antideuteron limits from experiment E864

In this paper we review preliminary data from experiment 864 for antiprotons and antideuterons produced in Au + Pb collisions at 11.6 A GeV c−1, as reported at strangeness and quark matter conference in 1997. We have measured the invariant multiplicity of antiprotons above midrapidity and at low transverse momentum. Comparisons with previously published antiproton yields from experiment E878 show a significant discrepancy. One possible explanation of this could be the contributions from strange antibaryons whose decay product antiprotons are accepted in our experiment. We also present upper limits on the production of antideuterons.

Search for New Metastable Particles Produced in Au + Au Collisions at10.8AGeV/c

We have investigated particle production using a zero degree two-segment focusing beam-line spectrometer, examining 2 x 10¹² Au+Au interactions at a beam momentum of 10.8AGeV/c. We have measured invariant cross sections for protons, various light nuclei (through {ital A}=6), antiprotons, and have set upper limits on the production of heavier nuclei, antideuterons, and strangelets. There is no evidence, within the sensitivity of our measurements, for the formation of new particles having lifetimes >100 ns. copyright 1995 The American Physical Society.

ARGUS results on antideuteron production

Using the ARGUS detector at the DORIS II storage ring we have studied the production of antideuterons in e +e − annihilation at centre-of-mass energies around 10 GeV. From 21 events containing d candidates we determined the inclusive cross section 1 σ dir had · dσ/ dp and the production rate in direct hadronic ϒ(1S), ϒ(2S) decays, which was measured to be (6.0 ± 2.0 ± 0.6)·10 −5 d per event while in the continuun e + e − → q q only an upper limit of 1.7. · 10 −5 d per event (90% CL) could be obtained. Comparisons with a simple model and other ARGUS measurements hint at the underlaying production mechanism of antideuterons.

Study of antideuteron production in e + e − annihilation at 10 GeV centre-of-mass energy

We report a measurement of the production of antideuterons d in e +e − annihilation at centre-of-mass energies around 10 GeV using the ARGUS detector at the DORIS II storage ring. We observe an enhancement of d production in direct hadronic ϒ(1S) and ϒ(2S) resonance decays. From 21 events width a d candidate the inclusive cross section 1 σ dir had · dσ dp and the production rate of antideuterons are determined. A production rate of (6.0±2.0±0.6) × 10 -5 d per direct hadronic ϒ decay and a 90% CL upper limit of 1.7 × 10 −5 d per e +e −→q q continuum event are obtained. These results are related to antiproton production through a simple model.

Observation of antideuteron production in electron-positron annihilation at 10 GeV center of mass energy

The production of antideuterons has been observed in electron-positron annihilations at center-of-mass energies around 10 GeV. Antideuterons have been identified unambiguously by their energy loss in the drift chamber, their time-of-flight and the pattern of their energy deposition in the shower counters of the ARGUS detector. The production rate in the momentum range (0.6−1.8) GeV/ c is (1.6 −0.7 +1.0) × 10 −5 per hadronic event.

Large angle production of stable particles heavier than the proton and a search for quarks at the CERN intersecting storage rings

Measurements have been performed on production of particles with mass 1.5 GeV/ c 2 and charge ⩾ 2 3 for θ lab = 62.5° and s = 53 GeV . At p T = 0.7 GeV/ c the relative rate of production of antideuterons to π − is (5 ± 1) × 10 −5. The deuteron to antideuteron ratio is 3.7 ± 1.2. No new stable particle has been amongst 0.7 × 10 8 charged particles entering our detector.

Production of antideuterons by 43 GeV, 52 GeV and 70 GeV protons

The production of antideuterons on aluminium nuclei by 43 GeV, 52 GeV and 70 GeV protons has been measured.

Negative particle production at the 70 GeV IHEP accelerator

Data are presented on the yields of π −, K −, and p produced at small angles by 70 GeV proton-aluminium interactions. The momenta of the secondaries studied were greater than 40 GeV/ c. Upper limits have been obtained on the production of antideuterons and possible new particles up to a mass of 2.2 GeV in this new energy region.