Mon·Aug 15, 2011Monday·August 15, 2011

1. 01*

   Study of \gamma-charge correlation in heavy ion collisions, various approaches

   Prithwish Tribedy🇮🇳 · Subhasis Chattopadhyay🇮🇳 · Aihong Tang🇺🇸

   Event-by-event \gamma-charge correlation is used in studying systems going through QCD chiral phase transition. In this paper various methods for measuring \gamma-charge correlation in heavy ion collisions have been discussed. Dynamical fluctuation due to formation of domains of DCC that can affect \gamma-charge correlation has been discussed. We study known detector and statistical effects involved in these measurements and suggest suitable robust observables \Delta\nu_{dyn} and r_{m,1} sensitive to small \gamma-charge correlation signal. These variables are constructed based on moments of multiplicity distributions of photon and charged particles. Estimations of expected measurable signals of \gamma-charge correlation from various available models such as for ideal Boltzmann gas of pions, monte-carlo models based on transport and mini-jets have been discussed. Collision centrality dependence of the observables have been estimated from Central Limit Theorem and found to be consistent with the model predictions. We find that observables show high sensitivity to fraction of DCC events and have nonlinear dependence on fraction of pions carrying DCC signals. Variation of r_{m,1} with orders of its higher moments m is an observable to extract the nature and strength of \gamma-charge correlation.

   nucl-exhep-phPRC(2012)·8 citations
2. 02*

   Real-time spectroscopy of solar pp neutrinos using Nd-150

   K. Zuber🇩🇪

   The potential real-time spectroscopy of solar pp neutrinos using Nd-150 as target is investigated. The threshold of 196 keV would be the lowest of all solar neutrino experiments running so far. Experimental rates and parameters are discussed, about 580 SNU can be expected from pp-neutrinos and another 367 SNU from Be-7. Furthermore, it is investigated whether charged current reactions might cause a new background component for future double beta decay experiments based on a large amount of Nd-150.

   nucl-exastro-ph.SRhep-exhep-phPLB(2012)·8 citations
3. 03*

   Nuclear beta-decay measurements and |Vud|

   Dan Melconian🇺🇸

   Some recent work in nuclear beta decay related to the value of |Vud| is described along with some near-term goals for future measurements.

   nucl-ex1 citation
4. 04*

   Angular Dependence in Proton-Proton Correlation Functions in Central ${}^{40}Ca{+}^{40}Ca$ and ${}^{48}Ca{+}^{48}Ca$ Reactions

   V. Henzl🇺🇸 · M. A. Kilburn🇺🇸 · Z. Chajecki🇺🇸 · D. Henzlova🇺🇸 · W. G. Lynch🇺🇸 · D. Brown🇺🇸 · A. Chbihi🇫🇷 · D. Coupland🇺🇸 · P. Danielewicz🇺🇸 · R. deSouza🇺🇸 · M. Famiano🇺🇸 · C. Herlitzius🇺🇸 and 12 other authors

   The angular dependence of proton-proton correlation functions is studied in central ${}^{40}Ca{+}^{40}Ca$ and ${}^{48}Ca{+}^{48}Ca$ nuclear reactions at E=80 MeV/A. Measurements were performed with the HiRA detector complemented by the 4$\pi$ Array at NSCL. A striking angular dependence in the laboratory frame is found within p-p correlation functions for both systems that greatly exceeds the measured and expected isospin dependent difference between the neutron-rich and neutron-deficient systems. Sources measured at backward angles reflect the participant zone of the reaction, while much larger sources observed at forward angles reflect the expanding, fragmenting and evaporating projectile remnants. The decrease of the size of the source with increasing momentum is observed at backward angles while a weaker trend in the opposite direction is observed at forward angles. The results are compared to the theoretical calculations using the BUU transport model.

   nucl-exPRC(2012)·16 citations
5. 05*

   Vud from Nuclear Decays

   I.S. Towner🇺🇸 · J.C. Hardy🇺🇸

   The current value of Vud is determined from superallowed beta-decay experiments. Other methods, briefly summarised here, have to overcome specific experimental hurdles before they are competitive. However, the nuclear results do depend on a nuclear-structure calculation of isospin-symmetry breaking, which is often a cause of some concern. We show here, by adopting the Conserved Vector Current (CVC) hypothesis, that these theoretical corrections can be tested for consistency. In this test, calculations based on the shell model with Saxon-Woods radial functions perform the best.

   ↳ nucl-thhep-phnucl-ex1 citation
6. 06*

   Adiabatic versus Faddeev for (d,p) and (p,d) reactions

   F.M. Nunes🇺🇸 · A. Deltuva🇵🇹

   The finite range adiabatic wave approximation provides a practical method to analyze (d,p) or (p,d) reactions, however until now the level of accuracy obtained in the description of the reaction dynamics has not been determined. In this work, we perform a systematic comparison between the finite range adiabatic wave approximation and the exact Faddeev method. We include studies of ${}^{11}$Be(p,d)${}^{10}$Be(g.s.) at $E_p=$5, 10 and 35 MeV; ${}^{12}$C(d,p)${}^{13}$C(g.s.) at $E_d=$7, 12 and 56 MeV and ${}^{48}$Ca(d,p)${}^{49}$Ca(g.s.) at $E_d=$19, 56 and 100 MeV. Results show that the two methods agree within $\approx 5$ for a range of beam energies ($E_d\approx 20-40$ MeV) but differences increase significantly for very low energies and for the highest energies. Our tests show that ADWA agrees best with Faddeev when the angular momentum transfer is small $\Delta l=0$ and when the neutron-nucleus system is loosely bound.

   ↳ nucl-thnucl-exPRC(2011)·58 citations
7. 07*

   Transfer reactions and the dispersive optical-model

   N.B.Nguyen🇺🇸 · S.J.Waldecker🇺🇸 · F.M.Nunes🇺🇸 · R.J.Charity🇺🇸 · W.H.Dickhoff🇺🇸

   The dispersive optical-model is applied to transfer reactions. A systematic study of $(d,p)$ reactions on closed-shell nuclei using the finite-range adiabatic reaction model is performed at several beam energies and results are compared to data as well as to predictions using a standard global optical-potential. Overall, we find that the dispersive optical-model is able to describe the angular distributions as well as or better than the global parameterization. In addition, it also constrains the overlap function. Spectroscopic factors extracted using the dispersive optical-model are generally lower than those using standard parameters, exhibit a reduced dependence on beam energy, and are more in line with results obtained from $(e,e^{\prime }p)$ measurements.

   ↳ nucl-thnucl-exPRC(2011)·23 citations
8. 08*

   DN interaction from the Juelich meson-exchange model

   L. Tolos🇪🇸 · J. Haidenbauer🇩🇪 · G. Krein🇧🇷

   The $DN$ interaction is studied in close analogy to the meson-exchange $\bar{K}N$ potential of the Juelich group using SU(4) symmetry constraints. The model generates the ${\Lambda }_c$(2595) resonance dynamically as a $DN$ quasi-bound state. Results for $DN$ scattering lengths and cross sections are presented and compared with predictions based on the Weinberg-Tomozawa term. Some features of the ${\Lambda }_c$(2595) resonance are also discussed emphasizing the role of the near-by $\pi {\Sigma }_c$ threshold.

   ↳ hep-phnucl-exnucl-thAIP Conf.Proc.(2012)·0 citations
9. 09*

   High density cluster jet target for storage ring experiments

   Alexander Täschner🇩🇪 · Esperanza Köhler🇩🇪 · Hans-Werner Ortjohann🇩🇪 · Alfons Khoukaz🇩🇪

   The design and performance of a newly developed cluster jet target installation for hadron physics experiments are presented which, for the first time, is able to generate a hydrogen cluster jet beam with a target thickness of above $10^{15}{atoms/cm}^2$ at a distance of two metres behind the cluster jet nozzle. The properties of the cluster beam and of individual clusters themselves are studied at this installation. Special emphasis is placed on measurements of the target beam density as a function of the relevant parameters as well as on the cluster beam profiles. By means of a time-of-flight setup, measurements of the velocity of single clusters and velocity distributions were possible. The complete installation, which meets the requirements of future internal fixed target experiments at storage rings, and the results of the systematic studies on hydrogen cluster jets are presented and discussed.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2011)·26 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.