Open system approach to Neutrino oscillations in a quantum walk framework

Quantum simulation provides a computationally-feasible approach to model and study many problems in chemistry, condensed-matter physics, or high-energy physics where quantum phenomenon define the systems behaviour. In high-energy physics, quite a few possible applications are investigated in the context of gauge theories and their application to dynamic problems, topological problems, high-baryon density configurations, or collective neutrino oscillations. In particular, schemes for simulating neutrino oscillations are proposed using a quantum walk framework. In this study, we approach the problem of simulating neutrino oscillation from the perspective of open quantum systems by treating the position space of quantum walk as environment. We have obtained the recurrence relation for Kraus operator which is used to represent the dynamics of the neutrino flavor change in the form of reduced coin states. We establish a connection between the dynamics of reduced coin state and neutrino phenomenology, enabling one to fix the simulation parameters for a given neutrino experiment and reduces the need for extended position space to simulate neutrino oscillations. We have also studied the behavior of linear entropy as a measure of entanglement between different flavors in the same framework.Comment: A section on 'Quantum circuit construction of PMNS Matrix' is adde

Nuclear Track Detectors. Searches for Exotic Particles

We used Nuclear Track Detectors (NTD) CR39 and Makrofol for many purposes: i) Exposures at the SPS and at lower energy accelerator heavy ion beams for calibration purposes and for fragmentation studies. ii) Searches for GUT and Intermediate Mass Magnetic Monopoles (IMM), nuclearites, Q-balls and strangelets in the cosmic radiation. The MACRO experiment in the Gran Sasso underground lab, with ~1000 m^2 of CR39 detectors (plus scintillators and streamer tubes), established an upper limit for superheavy GUT poles at the level of 1.4x10^-16 cm^-2 s^-1 sr^-1 for 4x10^-5 <beta<1. The SLIM experiment at the high altitude Chacaltaya lab (5230 m a.s.l.), using 427 m^2 of CR39 detectors exposed for 4.22 y, gave an upper limit for IMMs of ~1.3x10^-15 cm^-2 s^-1 sr^-1. The experiments yielded interesting upper limits also on the fluxes of the other mentioned exotic particles. iii) Environmental studies, radiation monitoring, neutron dosimetry.Comment: Talk given at "New Trends In High-Energy Physics" (experiment, phenomenology, theory) Yalta, Crimea, Ukraine, September 27-October 4, 200

Ultrahigh Energy Cosmic Rays: Facts, Myths, and Legends

This is a written version of a series of lectures aimed at graduate students in astrophysics/particle theory/particle experiment. In the first part, we explain the important progress made in recent years towards understanding the experimental data on cosmic rays with energies > 10^8 GeV. We begin with a brief survey of the available data, including a description of the energy spectrum, mass composition, and arrival directions. At this point we also give a short overview of experimental techniques. After that, we introduce the fundamentals of acceleration and propagation in order to discuss the conjectured nearby cosmic ray sources, and emphasize some of the prospects for a new (multi-particle) astronomy. Next, we survey the state of the art regarding the ultrahigh energy cosmic neutrinos which should be produced in association with the observed cosmic rays. In the second part, we summarize the phenomenology of cosmic ray air showers. We explain the hadronic interaction models used to extrapolate results from collider data to ultrahigh energies, and describe the prospects for insights into forward physics at the Large Hadron Collider (LHC). We also explain the main electromagnetic processes that govern the longitudinal shower evolution. Armed with these two principal shower ingredients and motivation from the underlying physics, we describe the different methods proposed to distinguish primary species. In the last part, we outline how ultrahigh energy cosmic ray interactions can be used to probe new physics beyond the electroweak scale.Comment: Lectures given at the 6th CERN-Latin-American School of High-Energy Physics, Natal, Brazil, March - April, 2011. (92 pages, 37 figures) Submitted for publication in a CERN Yellow Report. http://physicschool.web.cern.ch/PhysicSchool/CLASHEP/CLASHEP2011/