16990556
Effective dynamic range in measurements with flash analog-to-digital convertor
Flash Analog-to-Digital Convertor (FADC) is frequently used in Nuclear and Particle Physics experiments, often as the major component in big multi-channel systems. The large data volume makes the optimization of operating parameters necessary. This article reports a study of a method to extend the dynamic range of an 8-bit FADC from the nominal 28 value. By comparing the integrated pulse area with that of a reference profile, good energy reconstruction and event identification can be achieved on saturated events from CsI(TI) crystal scintillators. The effective dynamic range can be extended by at least four more bits. The algorithm is generic and is expected to be applicable to other detector systems with FADC readout. (C) 2003 Elsevier B.V. All rights reserved.
122336835
Validity of scaling relations between nucleon form factors
We prove, within the framework of analytic S-matrix theory and the physical mass spectrum, that the following scaling relations cannot be rigorously true for all t: (i) G M V (t)∝G E V (t), (ii) G M V (t)=R 1 (t)G E V (t)+R 2 (t), where R 1,2 (t) are rational functions of t, (iii) F Π (t)∝G E V (t), and (iv) F Π (t)∝G M V (t).
118579192
Multiplicity distributions of shower particles and target fragments in 84Kr36–emulsion interactions at 1 GeV per nucleon
This article focuses on multiplicity distributions of shower particles and target fragments for interaction of 84Kr36 with NIKFI BR-2 nuclear emulsion target at kinetic energy of ~1 GeV per nucleon. Experimental multiplicity distributions of shower particles, grey particles, black particles and heavily ionization particles are well described by multi-component Erlang distribution of multi-source thermal model. We have observed a linear correlation in multiplicities for the above mentioned particles or fragments. Further experimental studies have shown a saturation phenomenon in shower particle multiplicity with the increase of target fragment multiplicity.
119305151
Characteristics of compound multiplicity in 84Kr36 with various light and heavy targets at 1 GeV per nucleon
Interactions of 84Kr36 having kinetic energy around 1 GeV per nucleon with NIKFI BR-2 nuclear emulsion detector’s target reveal some of the important features of compound multiplicity. Present article shows that width of compound multiplicity distributions and value of mean compound multiplicity have linear relationship with mass number of the projectile colliding system.
119107308
Hadron spectra in p+p collisions at RHIC and LHC energies
We present the systematic analysis of transverse momentum (pT) spectra of identified hadrons in p+p collisions at Relativistic Heavy Ion Collider ( and 200 GeV) and at Large Hadron Collider (LHC) energies (, 2.76 and 7.0 TeV) using phenomenological fit functions. We review various forms of Hagedorn and Tsallis distributions and show their equivalence. We use Tsallis distribution which successfully describes the spectra in p+p collisions using two parameters, Tsallis temperature T which governs the soft bulk spectra and power n which determines the initial production in partonic collisions. We obtain these parameters for pions, kaons and protons as a function of center-of-mass energy . It is found that the parameter T has a weak but decreasing trend with increasing . The parameter n decreases with increasing which shows that production of hadrons at higher energies are increasingly dominated by point like qq scatterings. Another important observation is with increasing , the separation between the powers for protons and pions narrows down hinting that the baryons and mesons are governed by same production process as one moves to the highest LHC energy.
119188201
Emission characteristics of the projectile fragments at relativistic energy
A projectile (84Kr36) having kinetic energy around 1 A GeV has been used to expose NIKFI BR-2 emulsion target at GSI, Darmstadt, Germany. A total of 700 inelastic events has been identified and used in the present studies on projectile fragments. The emission angle of the projectile fragments are strongly affected by charge of the other projectile fragments emitted at same time with different emission angle is observed. The angular distribution studies show symmetrical nature for lighter charge projectile fragments. The symmetrical nature decreased with the charge of projectile fragments. We have observed at ~4o of emission angle for double charge projectile fragments, the momentum transfer during interaction is similar for various target species of emulsion. We have also observed a small but significant amplitude peaks on both side of the big peak for almost all light charge projectile fragments having different delta angle values. It reflects that there are a few percent of projectile fragments that are coming from the decay of heavy projectile fragments or any other process.
122369339
Electron identification and the detection of synchrotron radiation with a preshower detector
Abstract Results are presented from testbeam measurements made with a scintillating fiber preshower detector. The detector was designed to study the early development of electromagnetic showers and the conversion of synchrotron radiation photons. It was constructed with a 0.5 mm transverse granularity, and eight 0.25 radiation length ( X 0 ) longitudinal samplings. Data were taken with 50 GeV pions and electrons with energies between 10 and 200 GeV. Measurements, for electrons, of both the energy deposited and the shower width as a function of depth are presented in this paper. In addition, data were taken with a 1.8 m long magnet with a 2.5 T field placed directly upstream of the detector and the synchrotron radiation photons, generated by the electrons traversing it, were observed in our detector. Electron identification efficiencies and pion rejection factors based on the synchrotron radiation signal and the energy deposited in the last sampling layer (1.75 X 0 ) are presented.
119959917
Bounds on elastic absorptive parts
We reduce the general problem of obtaining bounds on elastic absorptive parts of a scattering amplitude subject to unitarity restrictions and any number of constraints involving partial wave amplitudes linearly to a form where it can be directly applied to any such problem. A series of bounds on absorptive parts for positive momentum transfer square t, within the Lehmann-Martin ellipse, is derived. These involve a knowledge of the first few momentum transfer derivatives of the absorptive part in the forward direction, i.e., t = 0. Upper and lower bounds on the higher t-derivatives of the absorptive part at t = 0 are also given.
56310271
Study of the shell effect on nuclear dissipation via neutron multiplicity measurement
Experimental neutron multiplicity data has been fitted using the Kramers' fission width, in statistical model calculations with and without inclusion of shell corrections in nuclear level density, nuclear masses and fission barrier. It has been found that the magnitude of dissipation strength changes to a large extent with inclusion of shell corrections in different ingredients of the statistical model. These observations clearly demonstrate the importance of shell corrections in statistical model calculations.
120223172
psi particles, SU(4), and anomalous currents
We propose assignment of the new ψ particles in an SU(4) symmetry scheme, incorporating SU(3) and a new additive quantum number, paracharge Z. Anomalous currents are introduced to account for the production and decays of these particles. Two more rather broad resonances at around 4.3 and 5.0 (±0.2) GeV are expected in the e + e - annihilation, one of which has recently been reported (at 4.15 GeV).
119834941
Analytic continued fraction theory for a class of confinement potentials
We study a general class of confinement potentials in Schrödinger theory using the analytic theory of continued fractions. We construct an infinite continued fraction representation for the Green's function and study its convergence, its analytic properties in the major coupling constant and its relation to the perturbation series. We prove the existence of normalizable confined state eigensolutions with equally spaced energy levels if certain constraints on the coupling constants of the theory are satisfied: we also show that under a separate set of constraints neither bound nor confined states exist.