Search results for "angular correlation"
showing 10 items of 345 documents
Evidence of oblate-prolate shape coexistence in the strongly-deformed nucleus 119Cs
2021
International audience; Prolate-oblate shape coexistence close to the ground state in the strongly-deformed proton-rich A≈120 nuclei is reported for the first time. One of the four reported bands in 119Cs, built on a 11/2− state at 670 keV, consists of nearly degenerate signature partners, and has properties which unequivocally indicate the strongly-coupled πh11/2[505]11/2− configuration associated with oblate shape. Together with the decoupled πh11/2[541]3/2− band built on the 11/2− prolate state at 110 keV, for which a half-life of T1/2=55(5)μs has been measured, the new bands bring evidence of shape coexistence at low spin in the proton-rich strongly deformed A≈120 nuclei, a phenomenon p…
Search for new physics inlepton+photon+Xevents with929 pb−1ofpp¯collisions ats=1.96 TeV
2007
The authors present results of a search for anomalous production of events containing a charged lepton ({ell}, either e or {mu}) and a photon ({gamma}), both with high transverse momentum, accompanied by additional signatures, X, including missing transverse energy (E{sub T}) and additional leptons and photons. We use the same kinematic selection criteria as in a previous CDF search, but with a substantially larger data set, 305 pb{sup -1}, a p{bar p} collision energy of 1.96 TeV, and the upgraded CDF II detector. We find 42 {ell}{gamma}E{sub T} events versus a standard model expectation of 37.3 {+-} 5.4 events. The level of excess observed in Run I, 16 events with an expectation of 7.6 {+-…
The Proton Spectrum in Neutron Beta Decay: Latest Results with the aSPECT Spectrometer
2009
Abstract The purpose of the neutron decay spectrometer aSPECT is to determine the antineutrino electron angular correlation coefficient a with high precision. Latest measurements with aSPECT were performed during April/May 2008 at the Institut Laue-Langevin in Grenoble, France. In this paper we give a report on the experiment and the status of the ongoing data analysis.
Searches for transverse momentum dependent flow vector fluctuations in Pb-Pb and p-Pb collisions at the LHC
2017
The measurement of azimuthal correlations of charged particles is presented for Pb-Pb collisions at $\sqrt{s_{\rm NN}}=$ 2.76 TeV and p-Pb collisions at $\sqrt{s_{\rm NN}}=$ 5.02 TeV with the ALICE detector at the CERN Large Hadron Collider. These correlations are measured for the second, third and fourth order flow vector in the pseudorapidity region $|��|<0.8$ as a function of centrality and transverse momentum $p_{\rm T}$ using two observables, to search for evidence of $p_{\rm T}$-dependent flow vector fluctuations. For Pb-Pb collisions at 2.76 TeV, the measurements indicate that $p_{\rm T}$-dependent fluctuations are only present for the second order flow vector. Similar results hav…
Insight into particle production mechanisms via angular correlations of identified particles in pp collisions at √s = 7 TeV
2017
Two-particle angular correlations were measured in pp collisions at s√=7 TeV for pions, kaons, protons, and lambdas, for all particle/anti-particle combinations in the pair. Data for mesons exhibit an expected peak dominated by effects associated with mini-jets and are well reproduced by general purpose Monte Carlo generators. However, for baryon–baryon and anti-baryon–anti-baryon pairs, where both particles have the same baryon number, a near-side anti-correlation structure is observed instead of a peak. This effect is interpreted in the context of baryon production mechanisms in the fragmentation process. It currently presents a challenge to Monte Carlo models and its origin remains an op…
Decays of110Rhand112Rhto the near neutron midshell isotopes110Pdand112Pd
1999
The decays ${}^{110}\mathrm{Rh}$ and ${}^{112}\mathrm{Rh}$ have been investigated using on-line mass separation with the ion-guide technique. Extended decay schemes have been constructed for both the low- and high-spin states in ${}^{112}\mathrm{Rh}$. Mixing ratios for the collective transitions from the ${2}_{2}^{+}$ and ${3}_{1}^{+}$ states in ${}^{112}\mathrm{Pd}$ have been measured by $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$ angular correlation. The presence of two sets of ${0}^{+}$ and ${2}^{+}$ states in the 1.1\char21{}1.4 MeV range suggests the existence of an intruder band, the energy of which is the lowest in ${}^{110}\mathrm{Pd}$ with two neutrons fewer than the mid…
Study of ordered hadron chains with the ATLAS detector
2017
The analysis of the momentum difference between charged hadrons in high-energy proton-proton collisions is performed in order to study coherent particle production. The observed correlation pattern agrees with a model of a helical QCD string fragmenting into a chain of ground-state hadrons. A threshold momentum difference in the production of adjacent pairs of charged hadrons is observed, in agreement with model predictions. The presence of low-mass hadron chains also explains the emergence of charge-combination-dependent two-particle correlations commonly attributed to Bose-Einstein interference. The data sample consists of 190 μb-1 of minimum-bias events collected with proton-proton colli…
Searching for the 5H resonance in the t+n+n system
2003
19 pages, 7 figures, 2 tables, 2 appendices.-- PACS nrs.: 27.10.+h; 25.60.Gc.-- Printed version published Jul 28, 2003.
Development of a γ-γ-perturbed angular correlation one-detector method (1-PAC) for investigation of physico-chemical properties of matter
2002
Abstract A new method of the perturbed angular γ – γ -correlation (PAC) measurements was developed using one HPGe detector only (1-PAC). For quantifying the perturbation factor, the ratio R γ 1 + γ 2 of the summing peak composed of two cascade γ -rays (the perturbation-affected parameter) to the summing peak composed of one γ -ray and one X-ray (the perturbation non-affected parameter) was used. This method was demonstrated for the radionuclides 111 In and 111m Cd, identifying the chemical status of the radionuclides in aqueous solutions.
Forward-central two-particle correlations in p–Pb collisions at √sNN = 5.02 TeV
2016
Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2 GeV/c. peerReviewed