Deuteron Production Research Articles

(Anti-)deuteron production and anisotropic flow measured with ALICE at the LHC

The high abundance of (anti-)deuterons in the statistics gathered in Run 1 of the LHC and the excellent performance of the ALICE setup allow for the simultaneous measurement of the elliptic flow and the deuteron production rates with a large transverse momentum (pT) reach. The (anti-) deuterons are identified using the specific energy loss in the time projection chamber and the velocity information in the time-of-flight detector. The elliptic flow of (anti-)deuterons can provide insight into the production mechanisms of particles in heavy-ion collisions. Quark coalescence is one of the approaches to describe the elliptic flow of hadrons, while the production of light nuclei can be also depicted as a coalescence of nucleons. In these proceedings, the measured v2 of deuterons produced in Pb–Pb collisions at sNN=2.76 TeV will be compared to expectations from coalescence and hydrodynamic models.

Anti–nuclei production at the LHC measured with ALICE

The excellent tracking and particle identification capabilities of the ALICE apparatus combined with the high particle production rates reached at the LHC in pp, p–Pb and in particular in Pb–Pb collisions allow for detailed study of the production of nuclei and anti-nuclei. In this paper, recent results on the production of the (anti-)deuteron and (anti-)helium are presented and compared with the expectations from statistical (thermal) particle production and coalescence models.

Production of light nuclei and anti-nuclei inppand Pb-Pb collisions at energies available at the CERN Large Hadron Collider

The production of (anti-)deuteron and (anti-)$^{3}$He nuclei in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV has been studied using the ALICE detector at the LHC. The spectra exhibit a significant hardening with increasing centrality. Combined blast-wave fits of several particles support the interpretation that this behavior is caused by an increase of radial flow. The integrated particle yields are discussed in the context of coalescence and thermal-statistical model expectations. The particle ratios, $^3$He/d and $^3$He/p, in Pb-Pb collisions are found to be in agreement with a common chemical freeze-out temperature of $T_{\rm chem} \approx 156$ MeV. These ratios do not vary with centrality which is in agreement with the thermal-statistical model. In a coalescence approach, it excludes models in which nucleus production is proportional to the particle multiplicity and favors those in which it is proportional to the particle density instead. In addition, the observation of 31 anti-tritons in Pb-Pb collisions is reported. For comparison, the deuteron spectrum in pp collisions at $\sqrt{s} = 7$ TeV is also presented. While the p/$\pi$ ratio is similar in pp and Pb-Pb collisions, the d/p ratio in pp collisions is found to be lower by a factor of 2.2 than in Pb-Pb collisions.

Recent results for the (anti-)(hyper-)nuclei production and searches for exotica by ALICE at the LHC

The excellent tracking and particle identification capabilities of the ALICE apparatus combined with the high particle production rates reached at the LHC in pp, p-Pb and in particular in Pb-Pb collisions allow for detailed study of the production of (anti-)(hyper-)nuclei and searches for exotica, like dibaryons. In this report, we present recent results on the production of the (anti-)deuteron and (anti-)helium. Further, we discuss recent results on the production and the lifetime of the (anti-)hypertriton. In addition, results from the searches for the weakly-decaying exotic nuclear bound states H-dibaryon and An are shown. The results are compared with the expectations from statistical (thermal) particle production and coalescence models.

Light (anti-)nuclei production and flow in relativistic heavy-ion collisions

Using the coalescence model based on the phase-space distributions of protons, neutrons, Lambdas and their antiparticles from a multiphase transport (AMPT) model, we study the production of deuteron, triton, helium 3, hypertriton, hyperhelium 3 and their antinuclei in Pb+Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV. The resulting transverse momentum spectra, elliptic flows and coalescence parameters for these nuclei are presented and compared with available experimental data. We also show the constituent number scaled elliptic flows of these nuclei and discuss their implications.

Observation of light nuclei at ALICE and theX(3872)conundrum

The new data reported by ALICE on the production of light nuclei with ${p}_{\ensuremath{\perp}}\ensuremath{\lesssim}10\text{ }\text{ }\mathrm{GeV}$ in Pb-Pb collisions at $\sqrt{{s}_{\mathrm{NN}}}=2.76\text{ }\text{ }\mathrm{TeV}$ are used to compute an order-of-magnitude estimate of the expected production cross sections of light nuclei in proton-proton collisions at high transverse momenta. We compare the hypertriton, helium-3, and deuteron production cross sections to that of $X(3872)$, measured in prompt $pp$ collisions by CMS. The results we find suggest a different production mechanism for the $X(3872)$, making questionable any loosely bound molecule interpretation.

Experimental search for the singlet metastable deuteron in the radiative n-p capture

We performed an experimental search for the bound state singlet deuteron predicted in some microscopic calculations. The predicted energy of this level is in vicinity of the deuteron disintegration threshold. This state should manifest itself in two-photon $$^3 \tilde S_1 \to ^1 S_0 \to ^3 S_1$$ transition following thermal neutron capture by protons. The experiment consists in the search for the second gamma-ray in the cascade through a high statistics measurement of γ-ray spectra after thermal neutron capture by hydrogen nuclei. The upper limit 15 μb is obtained for the cross section of the singlet deuteron production with the bound energy in the range 25–125 keV.

Multiplicity Dependence of (Anti-)Deuteron Production in p-Pb Collisions at = 5.02 TeV Measured with ALICE

The measurement of the (anti-)deuteron production as a function of transverse momentum and event multiplicity in p-Pb collisions at = 5.02 TeV is presented here. (Anti-)deuterons are identified via their energy loss dE/dx in the time projection chamber and via their time-of-flight. Their production will be discussed within the context of thermal and coalescence models.

Evaluated gas production cross-section data for natural titanium irradiated with protons at energies up to 3 GeV

Abstract Evaluated proton, deuteron, triton, 3He and 4He production cross-section data were prepared for natural titanium irradiated with protons at the energy up to 3 GeV. The evaluated data were obtained from the analysis of results of nuclear model calculations, available measured, and systematic data. The calculations of gas production cross-sections were carried out using the intranuclear cascade model (INC), the pre-equilibrium exciton model, geometry dependence hybrid (GDH) model, Weisskopf-Ewing (WE) model, and the Hauser-Feshbach model. CASCADE, TALYS, ALICE/ASH, and ALICE/HMS codes were used for calculations. Available experimental and systematic data, model calculations were used to evaluate gas production cross-section. The evaluation was carried out using statistical methods implemented in the BEKED code package developed at KIT/INR. The evaluated cross-sections were compared with the data from evaluated data libraries.

Comparative analysis of properties of channels of deuteron and tritium production in 16Op collisions at a projectile momentum of 3.25 GeV/c per nucleon

The results of a comparative analysis of channels involving the inclusive production of deuterons and tritons in 16Op collisions at a projectile momentum of 3.25 GeV/c per nucleon are presented. The mechanisms governing proton, deuteron, and triton production in the fragmentation of oxygen nuclei are found to be independent. It is shown that the observed proton-multiplicity correlations are associated predominantly with the character of the primary event of a proton-nucleon collision in 16Op interactions. It is found that, in reactions involving triton production, the contributions of processes leading to an increase in the mean proton multiplicity (n → p + π− and np → pn) and processes leading to its decrease (p → n + π+) compensate each other.

Search for exotic hyper-matter and measurement of nuclei with ALICE at the LHC

The high collision energies reached at the LHC lead to significant production yields of light (anti)-nuclei and hyper-matter in proton-proton and, in particular, Pb-Pb collisions. The excellent particle identification capabilities of the ALICE apparatus, in particular the specific energy loss in the Time Projection Chamber (TPC) and Time-of-Flight (TOF) measurement, allow for the detection of such rarely produced particles. Further, the Inner Tracking System (ITS) gives the possibility to separate primary nuclei from those coming from the weak decay of heavier systems. This offers the unique opportunity to search for exotica like the bound state of a A and a neutron which would decay into deuteron and pion, or the bound states of two As. We show here the performance of the ALICE apparatus in the sector on (anti-)nuclei and in particular the results on deuteron production in Pb-Pb collisions at = 2.76 TeV. These are compared with thermal model predictions. We further present the current state of the searches, by their upper limits on the production yields, and compare the results to thermal and coalescence model expectations.

On some properties of deuteron and antideuteron production in high energy lead–lead collisions at 158A GeV

We would attempt here to understand some properties of the transverse momentum (pT) and rapidity (y) spectra on production of deuteron (d) and antideuteron ([Formula: see text]) in lead–lead ( Pb + Pb ) collisions at 158A GeV recently reported by NA49 Collaboration. Starting from some basic properties of nucleon–nucleon (p + p) reactions for production of secondary proton–antiprotons the cases of production of the composite set of particles, like d and [Formula: see text], would be analyzed. Some ratio-behaviors would also be dealt within the light of the same approaches. It is found that the combination of the models put into use here capture modestly well the trends of the data on some important observables. Some limitations of the approach would also be pointed out in the end.

Measurements of 186Re production cross section induced by deuterons on natW target at ARRONAX facility

IntroductionThe ARRONAX cyclotron, acronym for “Accelerator for Research in Radiochemistry and Oncology at Nantes Atlantique” is a new facility installed in Nantes, France. A dedicated program has been launched on production of innovative radioisotopes for PET imaging and for β− and α targeted radiotherapy using protons or α particles. Since the accelerator is also able to deliver deuteron beams up to 35MeV, we have reconsidered the possibility of using them to produce medical isotopes. Indeed, in some cases, the use of deuterons allows higher production yield than protons. Methods186Re is a β− emitter which has chemical properties close to the widely used 99mTc and has been used in clinical trials for palliation of painful bone metastases resulting from prostate and breast cancer. 186Re production cross section has been measured between 9 and 23MeV using the ARRONAX deuteron beam and the stacked-foil technique.A novelty in our work is the use of a monitor foil behind each natW target foil in order to record efficiently the deuteron incident flux and energies all over the stack relying on the International Atomic Energy Agency (IAEA) recommended cross section of the natTi(d,x)48V reaction. Since a good optimization process is supposed to find the best compromise between production yield and purity of the final product, isotope of interest and contaminants created during irradiation are measured using gamma spectrometry. ResultsOur new sets of data are presented and compared with the existing ones and with results given by the TALYS code calculations. The thick target yield (TTY) has been calculated after the fit of our experimental values and compared with the IAEA recommended ones. ConclusionsPresented values are in good agreement with existing data. The deuteron production route is clearly the best choice with a TTY of 7.8MB/μAh at 30MeV compared to 2.4MBq/μAh for proton as projectile at the same energy. The TALYS code gives satisfactory results for 183,186Re isotopes.

Inclusive production of protons, anti-protons, neutrons, deuterons and tritons in p+C collisions at 158 GeV/c beam momentum

The production of protons, anti-protons, neutrons, deuterons and tritons in minimum bias p+C interactions is studied using a sample of 385 734 inelastic events obtained with the NA49 detector at the CERN SPS at 158 GeV/c beam momentum. The data cover a phase space area ranging from 0 to 1.9 GeV/c in transverse momentum and in Feynman x from −0.8 to 0.95 for protons, from −0.2 to 0.3 for anti-protons and from 0.1 to 0.95 for neutrons. Existing data in the far backward hemisphere are used to extend the coverage for protons and light nuclear fragments into the region of intra-nuclear cascading. The use of corresponding data sets obtained in hadron–proton collisions with the same detector allows for the detailed analysis and model-independent separation of the three principle components of hadronization in p+C interactions, namely projectile fragmentation, target fragmentation of participant nucleons and intra-nuclear cascading.

Proton-hydrogen reaction in an effectively two-body model

A model of total interaction between a proton incident to a hydrogen atom and the proton that is the nucleus of this atom is proposed. This interaction is assumed to be the sum of the short-range nuclear Reid potential and the long-range Thomas-Fermi potential induced by the Coulomb interaction of the electron with the nucleus of the hydrogen atom. The explicit low-energy asymptotic behavior of the cross section for the proton-hydrogen reaction leading to deuteron production is found. It is shown that this cross section increases in inverse proportion to the collision energy for the proton and hydrogen atom in its zero limit.

New results from the NA49 experiment on hadron production in p+p and p+C interactions and survey of backward hadrons in p+C collisions

Recent results on proton, anti-proton, neutron and charged kaon production in proton-proton and proton, anti-proton, neutron, deuteron and triton production in proton-carbon collisions at 158 GeV/c beam momentum are presented. Data samples of 4.8 million and 385 734 inelastic events in p+p and p+C, respectively, are obtained with the NA49 detector at the CERN SPS accelerator. The charged particles are identified by energy loss measurement in a system of four TPC chambers, while the neutrons are detected in a forward hadronic calorimeter. The data cover a major fraction of the phase space, ranging from 0 to 1.9 GeV in pT and in Feynman x variable from -0.8 to 0.95 for protons, from -0.2 to 0.3 for anti-protons, from 0.1 to 0.95 for neutrons and from 0 to 0.5 for kaons. The comparison of the results on proton and neutron production in p+p interactions and deep inelastic e+p collisions at HERA reveals an independence of target fragmentation on the projectile type. Using the charged kaon data in p+p collisions as a reference, a new evaluation of the energy dependence of kaon production, including neutral kaons, is conducted over a range from 3 GeV to p+p− collider energies. A survey of backward production of protons and pions in p+C collisions in the range of lab angles from 10 to 180 degrees, from 0.2 to 1.2 GeV/c in lab momentum and from 1 to 400 GeV/c in projectile momentum has been performed.

Antideuterons from dark matter annihilations and hadronization model dependence

We calculate the antideuteron yield in dark matter annihilations on an event-by-event basis using the HERWIG++ Monte Carlo generator. We present the resulting antideuteron fluxes for quark and gauge boson final states. As deuteron production in the coalescence model depends on momentum differences between nucleons that are small compared to \Lambda_{QCD}, it is potentially very sensitive to the hadronization model employed. We therefore compare our antideuteron yields to earlier results based on PYTHIA, thereby estimating their uncertainties. We also briefly discuss the importance of n>2 final states for annihilations of heavy DM particles.

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.

Cross-sections of large-angle hadron production in proton– and pion–nucleus interactions VIII: aluminium nuclei and beam momenta from ±3 GeV/c to ±15 GeV/c

We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% λ int thick stationary aluminium target, of proton and pion beams with momentum from ±3 GeV/c to ±15 GeV/c. Results are given for secondary particles with production angles 20∘<θ<125∘. Cross-sections on aluminium nuclei are compared with cross-sections on beryllium, carbon, copper, tin, tantalum and lead nuclei.

Special features of deuteron production in 16Op collisions at a momentum of 3.25 GeV/c per nucleon

New experimental data on the dependences of the mean multiplicities and kinematical characteristics of deuterons produced in 16Op collisions at a momentum of 3.25 GeV/c per nucleon on the degree of excitation of the fragmenting nucleus are presented. These experimental data are compared with the predictions of the cascade-fragmentation-evaporation model.