Generation (particle physics)

In particle physics, a generation or family is a division of the elementary particles. Between generations, particles differ by their flavour quantum number and mass, but their electric and strong interactions are identical. There are three generations according to the Standard Model of particle physics. Each generation contains two types of leptons and two types of quarks. The two leptons may be classified into one with electric charge −1 (electron-like) and neutral (neutrino); the two quarks may be classified into one with charge − (down-type) and one with charge + (up-type). The basic features of quark-lepton generation or families, such as their masses and mixings etc., can be described by some of the proposed family symmetries. Overview Each member of a higher generation has greater mass than the corresponding particle of the previous generation, with the possible exception of the neutrinos (whose small but non-zero masses have not been accurately determined). For exa

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PHYS-415: Particle physics I

Presentation of particle properties, their symmetries and interactions. Introduction to quantum electrodynamics and to the Feynman rules.

PHYS-439: Introduction to astroparticle physics

We present the role of particle physics in cosmology and in the description of astrophysical phenomena. We also present the methods and technologies for the observation of cosmic particles.

PHYS-416: Particle physics II

Presentation of the electroweak and strong interaction theories that constitute the Standard Model of particle physics. The course also discusses the new theories proposed to solve the problems of the Standard Model.

Dendrimer-Stabilized Titanate Nanowire Dispersions as Potential Nanocarriers

László Forró, Endre Horvath, Marko Pavlovic

The effect of poly(amido amine) (PAMAM) dendrimers of generations G2, G6, and G10 on the dispersion stability of titanate nanowires (TiONWs) as potential nanocarriers was clarified in order to develop biocompatible delivery systems. The PAMAMs adsorbed strongly on the oppositely charged TiONWs even under slightly alkaline conditions where the macromolecules possess low amounts of charged groups and they were able to reverse the charge of the particles. This process resulted in unstable dispersions near the dose where the charge reversal occurred, while stable samples were observed away from it. No generation dependence was found on the aggregation and charging behavior at low ionic strengths. Although heterogeneous adsorption of the dendrimers led to attractive patch-charge interactions at intermediate doses, interparticle forces of electrostatic origin described by Derjaguin and Landau, Verwey, and Overbeek (DLVO) played the major role in colloidal stability. The nanowires were found to adopt a face-to-face orientation within the aggregates, giving rise to the formation of well-defined bundles. Highly stable dispersions were observed once the TiONWs were coated with PAMAM dendrimers of higher generations even at elevated ionic strengths.

Amer Chemical Soc2015

Sleptonic SUSY: from UV framework to IR phenomenology

Majid Ekhterachian, Zhen Liu

We study an attractive scenario, "Sleptonic SUSY", which reconciles the 125 GeV Higgs scalar and the non-observation of superpartners thus far with potentially pivotal roles for slepton phenomenology: providing viable ongoing targets for LHC discovery, incorporating a co-annihilation partner for detectable thermal relic dark matter, and capable of mediating the potential muon g - 2 anomaly. This is accomplished by a modestly hierarchical spectrum, with sub-TeV sleptons and electroweakinos and with multi-TeV masses for the other new states. We study new elements in the UV MSSM realization of Sleptonic SUSY based on higher-dimensional sequestering and the synergy between the resulting gaugino-mediation, hypercharge D-term mediation and Higgs-mediation of SUSY-breaking, so as to more fully capture the range of possibilities. This framework stands out by harmoniously solving the flavor, CP and mu - B mu problems of the supersymmetric paradigm. We discuss its extension to orbifold GUTs, including gauge-coupling and b-tau unification. We also develop a non-minimal model with extra Higgs fields, in which the electroweak vacuum is more readily cosmologically stable against decay to a charge-breaking vacuum, allowing a broader range of sleptonic spectra than in the MSSM alone. We survey the rich set of signals possible at the LHC and future colliders, covering both R-parity conservation and violation, as well as for dark matter detection. While the multi-TeV squarks imply a Little Hierarchy Problem, intriguingly, small changes in parameter space to improve naturalness result in dramatic phase transitions to either electroweak-preservation or charge-breaking. In a Multiverse setting, the modest unnaturalness may then be explained by the "principle of living dangerously".

SPRINGER2022

Gauge coupling unification without leptoquarks

Georgios Karananas

We propose an interpretation of the gauge coupling unification scale which is not related to any new particle threshold. We revisit Grand Unified Theories and show that it is possible to completely eliminate the scalar as well as vector leptoquarks from the particle physics spectrum. As a consequence, in our approach the gauge hierarchy problem is put on different grounds, and the proton may be absolutely stable. In order to achieve that, we employ a number of nonlinear gauge-invariant constraints which only affect the superheavy degrees of freedom. We illustrate our considerations in a model based on the SU(5) group, with the generalization to other groups being straightforward. We discuss how scale or conformal invariance may be added to our proposal. (C) 2017 The Author(s). Published by Elsevier B.V.

2017

Standard Model

The Standard Model of particle physics is the theory describing three of the four known fundamental forces (electromagnetic, weak and strong interactions – excluding gravity) in the universe and cla

Quark

A quark (kwɔːrk,_kwɑːrk) is a type of elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and

Particle physics

Particle physics or high energy physics is the study of fundamental particles and forces that constitute matter and radiation. The fundamental particles in the universe are classified in the Standard