Calculation of right-handed fraction of leptons (pi decay)

In summary, the conversation revolves around understanding recurring formulas in homework solutions and their general validity and derivation. The specific example problem involves the decay of pi^- via electrons or muons, with a goal to correct the measured ratio of R = 1.3e-4. The solution involves the use of the branching ratio formula R = 3.3 * (1-\beta_e)/(1-\beta_\mu), considering that W bosons only couple to left-handed particles and right-handed anti-particles. The conversation also delves into the conservation of angular momentum and the concept of left-handed and right-handed particles. The speaker is seeking clarification on the general formula for the amount of left-handed and right-handed particles and how these formulas were originally
  • #1
black1corn

Homework Statement


I would like to understand whether reocurring formulas in the example solutions to my homework problems hold in general and ideally where they're derived from. (I'm new here; if there's there a way to embed formulas in f.i. latex code please tell me.)
As an example problem: pi^- can decay via electrons or muons. Phase space considerations lead to a branching ratio of w = 3.3 (electrons would be produced much more likely). The goal of the execise is to correct this ratio to the one measured in experiments (R = 1.3e-4), considering that W bosons couple only to left-handed particles and right-handed anti-particles.
The solution is given by:

Homework Equations


R = 3.3 * \frac{1-\beta_e}{1-\beta_\mu}
3. The Attempt at a Solution [/B]
From angular momentum conservation it's clear to me that lepton and corresponding anti-neutrino both have to be right-handed as for pi^-: J^P=0^-. It's intuitively clear to me that the (suppressed) right-handed fraction of leptons is smaller and thus an amount of 1-\beta (=1-p/E) makes sense for the momenta in question. What I don't know/am able to find out is whether generally the amount of left-handed particles is \beta and the right-handed amount 1-\beta and how these formulas were originally found.

Any clarification on this would be greatly appreciated.
 
Physics news on Phys.org

1. What is the purpose of calculating the right-handed fraction of leptons in pi decay?

The right-handed fraction of leptons is a measure of the asymmetry in the decay of the pion, a subatomic particle. It is used to study the fundamental interactions of particles and to test the predictions of the Standard Model of particle physics.

2. How is the right-handed fraction of leptons calculated?

The right-handed fraction of leptons is calculated by comparing the number of leptons that emerge from the decay of a pion in a specific direction with the total number of leptons produced in all directions. This calculation involves complex mathematical equations that take into account the properties of the pion and the interactions of particles in the decay process.

3. What is the significance of the right-handed fraction of leptons in particle physics?

The right-handed fraction of leptons is significant because it provides insight into the fundamental forces and interactions that govern the behavior of particles. It can also help to identify the existence of new particles or interactions beyond those predicted by the Standard Model.

4. How does the right-handed fraction of leptons vary in different types of pi decay?

The right-handed fraction of leptons can vary in different types of pi decay depending on the properties of the pion and the particles involved in the decay process. It can also vary with the energy of the particles and the angle at which the leptons are measured.

5. What are the potential implications of the right-handed fraction of leptons for our understanding of the universe?

The right-handed fraction of leptons is a crucial tool for testing the predictions of the Standard Model and for searching for new physics beyond it. Any deviations from the expected value could lead to new discoveries and a deeper understanding of the fundamental nature of the universe. It also has potential applications in fields such as particle accelerators and medical imaging technology.

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