Can someone explain conserved quantities in this activity

Click For Summary

Discussion Overview

The discussion revolves around understanding conserved quantities in a specific activity related to particle physics, particularly focusing on baryon number, electric charge, and lepton number. Participants seek clarification on how these quantities are determined in observed and unobserved events within the context of the activity.

Discussion Character

  • Exploratory
  • Technical explanation
  • Homework-related

Main Points Raised

  • One participant requests help with an activity and expresses confusion over the answer to a specific question.
  • Another participant explains that to determine conserved quantities, one should compare the sums of charges and baryons before and after reactions, noting that if these sums differ, the quantity is not conserved.
  • A participant acknowledges a mistake in the provided link and asks for clarification using examples of observed and unobserved events.
  • Concerns are raised about the presence of lepton number in observed events that do not contain leptons, questioning how a lepton number can be assigned in such cases.
  • One participant clarifies that the lepton number can be zero in certain cases, such as for baryons.
  • A participant expresses gratitude and indicates that they now understand the topic better.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the interpretation of lepton numbers in observed events, as there is uncertainty regarding how to account for lepton number when leptons are absent.

Contextual Notes

Participants discuss the definitions and implications of conserved quantities without resolving the complexities involved in the assignment of lepton numbers in specific scenarios.

Physics news on Phys.org
Your link to the answer page is the same as the other link.

The basic concept to find those quantities: For each observed event, list the sum of charges, number of baryons and so on at both sides (before and after the reaction). If one of those numbers differ in any allowed reaction, the quantity is not conserved. If they are always the same, it might be a conservation rule (you cannot prove conservation rules, just see that you cannot find a violation).

The unobserved events can give you a hint which properties might be interesting to look at, especially if both sides are very similar.
 
also as the answers are baryon number, electric charge and lepton number
in the question it says that all three quantities should be in all the observed events while at least one is missing from all the unobserved events
I can kinda find the missing ones in the unobserved events but the observed events some of them don't have any leptons to begin with, then how can they have lepton number?
 
In this case the lepton number is 0. (the lepton number of a baryon is 0)
 
i think i get it now
thanks for all the help guys :D
 

Similar threads

  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 22 ·
Replies
22
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 35 ·
2
Replies
35
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
8
Views
2K