Zini Rahman

The discovery reach of CP violation in neutrino oscillation with non-standard interaction effects

We have studied the CP violation discovery reach in a neutrino oscillation experiment with superbeam, neutrino factory and monoenergetic neutrino beam from the electron capture process. For NSI satisfying model-dependent bound for shorter baselines (like CERN-Frejus set-up) there is insignificant effect of NSI on the the discovery reach of CP violation due to δ. Particularly, for the superbeam and neutrino factory we have also considered relatively longer baselines for which there could be significant NSI effects on CP violation discovery reach for higher allowed values of NSI. For the monoenergetic beam only shorter baselines are considered to study CP violation with different nuclei as neutrino sources. Interestingly for non-standard interactions— and of neutrinos with matter during propagation in longer baselines in the superbeam, there is the possibility of better discovery reach of CP violation than that with only Standard Model interactions of neutrinos with matter. For complex NSI we have shown the CP violation discovery reach in the plane of Dirac phase δ and NSI phase . The CP violation due to some values of δ remain unobservable with present and near future experimental facilities in the superbeam and neutrino factory. However, in the presence of some ranges of off-diagonal NSI phase values there are some possibilities of discovering total CP violation for any value even at confidence level for neutrino factory. Our analysis indicates that for some values of NSI phases total CP violation may not be at all observable for any values of δ. Combination of shorter and longer baselines could indicate in some cases the presence of NSI. However, in general for NSIs the CP violation discovery reach is better in neutrino factory set-ups. Using a neutrino beam from the electron capture process for nuclei Sn and 152Yb, we have shown the discovery reach of CP violation in a neutrino oscillation experiment. Particularly for Sn nuclei CP violation could be found for about 51% of the possible δ values for a baseline of 130 km with boost factor . Although the nuclei 152Yb is technically more feasible for the production of a mono-energetic beam, it is found to be unsuitable in obtaining good discovery reach of CP violation.

Quantum Eraser Using a Modified Stern-Gerlach Setup

We propose a new setup to demonstrate quantum eraser, using spin-1/2 particles in a modified Stern-Gerlach setup, with a double slit. The which-way information can be erased simply by applying a transverse magnetic field with an additional magnet, resulting in the emergence of two complementary staggered interference patterns. Use of the classic SternGerlach setup, and the unweaving of the washed out interference without any coincident counting, is what makes this proposal novel. Subject Index: 061 §1. Complementarity and quantum eraser It is well known that particles and light both, are capable of exhibiting a dual nature. This is commonly referred to as wave-particle duality. What is commonly not emphasized, is the fact that these natures are mutually exclusive — for example, light can act either as a particle, or as a wave at a time. This has its foundation in Bohr’s complementarity principle. 1) It can be best understood in the context of Young’s double slit experiment with particles. Complementarity principle implies that in such an experiment, there is a fundamental incompatibility between the “Welcher-Weg”, or which-way information and the observation of interference pattern. Thus any attempt to obtain information about which slit the particle went through, necessarily destroys the interference pattern. Replying to Einstein’s famous thought experiment regarding a recoiling double-slit, Bohr had demonstrated that the uncertainty in the initial position of the double-slit is precisely enough to wash out the interference pattern. However, it turns out that it was just fortuitous that the uncertainty principle seemed to wash out the interference pattern. It has been argued that one could have the which-way information without appreciably affecting the spatial part of the wave function of the particle. 2) This can be done by entanglement of the particle with a variable, playing the role of a which-way marker. So, uncertainty principle is not the fundamental reason for washing out of interference in a double-slit experiment entanglement is. The double-slit experiment, with entanglement can be understood in the following way. Let us now assume that the initial state of the particle was entangled with

Discovery reach of CP violation in neutrino oscillation experiments with standard and non-standard interactions

Considering the value of mixing angle ?13 as obtained in recent Daya Bay and MINOS experiments we have explored the discovery reach of CP violation in the leptonic sector due to complex ? phase in neutrino oscillation experiments with superbeam. We have considered two experimental set-up corresponding to two baselines of 130 Km and 2300 Km respectively. Considering numerical simulation we have shown how the discovery reach of CP violation will change due to the presence of various non-standard interactions (NSIs). Although it is known that short baseline is better choice for CP violation study for Standard Model (SM) interactions of neutrinos with matter but in presence of NSI we find that sometimes better discovery reach is possible in relatively longer baselines.