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.
35249306
Quantum violation of stochastic noncontextual hidden-variable theories.
We formulate stochastic noncontextual hidden-variable theories. In such theories the hidden state λ specifies not definite values, but expectation values A − (λ), ... of observables A, ... and noncontextuality means that A − (λ) is independent of which other commuting observables commuting with A are measured together with A. We show via Bell inequalities that such theories conflict with quantum theory and propose a two-photon experimental test. We also show that for a single particle of spin (2 n −1)/2, quantum violation of classical noncontextuality grows exponentially with n.
117295648
REGGE POLES AND ASYMPTOTIC BEHAVIOR IN THE ANALYTIC CONTINUATION OF THE PION-NUCLEON SCATTERING AMPLITUDE
37383185
JOINT PROBABILITIES REPRODUCING THREE EPR EXPERIMENTS ON TWO QUBITS
An eight-parameter family of the most general non-negative quadruple probabilities is constructed for EPR–Bohm–Aharonov experiments when only three pairs of analyser settings are used. It is a simultaneous representation of three different Bohr-incompatible experimental configurations involving mutually noncommuting observables valid for arbitrary quantum states.
123580858
Unitarity upper bound on the absorptive parts of elastic scattering amplitudes
We derive a unitarity upper bound on the absorptive part A(s, t) of the elastic-scattering amplitude in the physical region. In the diffraction peak region the bound on A(s, t)/A(s, 0) is a function only of the parameter σ tot 2 (−t)/4πσ el . Assuming the diffraction scattering to be purely absorptive and spin independent we find the pp, pp, and π ± p data to lie a little below the theoretical upper bound. Further the experimental curve of X(t)/X(0) vs −4tX(0)/σ el , where X(t)≡dσ/dt, seems "universal."
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).
120331693
Bianchi Type-I Cosmological Model Filled with Viscous Fluid in a Modified Brans-Dicke Cosmology
Adding the cosmological term, which is assumed to be variable in Brans-Dicke theory we have discussed about a Bianchi type-I cosmological model filled with viscous fluid with free gravitational field of Petrov type-D. The effect of viscousity on various kinematical parameters has been discussed. Finally, this model has been transformed to the original form (1961) of Brans-Dicke theory including a variable cosmological term.
118383356
System size dependence of hadron $p_T$ spectra in p+p and Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV
We make a systematic study of transverse momentum ($p_T$) spectra of hadrons produced in $p+p$ and in different centralities of Au+Au collisions at $\sqrt{s}=200$\,GeV using phenomenological fit functions. The Tsallis distribution gives a very good description of hadron spectra in $p+p$ collisions with just two parameters but does not produce the same in Au+Au collisions at intermediate $p_{T}$. To explain the hadron spectra in heavy ion collisions in a wider $p_{T}$ range we propose a modified Tsallis function by introducing an additional parameter which accounts for collective flow. The new analytical function gives a very good description of both mesons and baryons spectra at all centralities of Au+Au collisions in terms of parameters having a potential physics interpretation. With this modified Tsallis function we study the spectra of pions, kaons, protons, $\Lambda(1115)$ and $\Xi^{-}$ as a function of system size at $\sqrt{s_{NN}}$ = 200 GeV. The parameter representing transverse flow increases with system size and is found to be more far baryons than that for mesons in central Au+Au collisions. The freeze-out temperature for baryons increases with centrality in Au+Au collisions more rapidly than for mesons.
118562891
Constraints on Non-Commutative Physics Scale with Neutrino-Electron Scattering
Neutrino-electron scatterings ($\ensuremath{\nu}\ensuremath{-}e$) are purely leptonic processes with robust standard model predictions. Their measurements can therefore provide constraints to physics beyond the standard model. Noncommutative (NC) field theories modify space-time commutation relations, and allow neutrino electromagnetic couplings at the tree level. Their contribution to the neutrino-electron scattering cross section was derived. Constraints were placed on the NC scale parameter ${\ensuremath{\Lambda}}_{\mathrm{NC}}$ from $\ensuremath{\nu}\ensuremath{-}e$ experiments with reactor and accelerator neutrinos. The most stringent limit of ${\ensuremath{\Lambda}}_{\mathrm{NC}}g3.3\text{ }\text{ }\mathrm{TeV}$ at 95% confidence level improves over the direct bounds from collider experiments.
119195821
Probing Radio Emission in Seyfert Galaxies on Parsec- and Kiloparsec-scales
Seyfert galaxies have traditionally been classified as radio-quiet active galactic nuclei. A proper consideration of the nuclear optical emission however proves that a majority of Seyferts are radio-loud. Kpc-scale radio lobes/bubbles are in fact revealed in sensitive observations at low radio frequencies of several Seyferts. Through the use of very long baseline interferometry, we have been able to determine the direction of the parsec-scale jets in some of these Seyfert galaxies. The misalignment between the parsec-scale jets and the kpc-scale lobes that is typically observed, is either suggestive of no connection between the two, or the presence of curved jets that power the radio lobes. In this context, we briefly discuss our new low radio frequency GMRT observations of two Seyfert galaxies with lobes.
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).