Chapter 12: Problem 14

Some neutral particles, like the \(\pi^{0}\), are their own antiparticles, but not the neutron. In what ways are \(n\) and \(\bar{n}\) the same? Speculate on how they might be different.

Short Answer

Expert verified

Answer: Neutrons and antineutrons are the same in terms of mass, charge, and spin, as both are neutral particles. However, they are different in their quark content, with neutrons consisting of one up quark and two down quarks, while antineutrons have one anti-up quark and two anti-down quarks. This difference in quark content leads to distinct interactions, annihilations, and decays between the two particles.

Step by step solution

Similarities between neutron and antineutron in terms of mass, charge, and spin

Firstly, let's discuss the similarities. The neutron and the antineutron both have the same mass, which is approximately \(937.9\,\text{MeV/c}^2\). They are both neutral particles which means they have no net electric charge. They also have the same value of intrinsic angular momentum, or spin, which is \(\frac{1}{2}\hbar\).

Quark content of the neutron and antineutron

Now, we must talk about the quark content of these particles. The neutron consists of three quarks: one up quark and two down quarks (denoted as \(u, d, d\)). The antineutron also consists of three quarks: one anti-up quark and two anti-down quarks (denoted as \(\bar{u}, \bar{d}, \bar{d}\)).

Differences between the neutron and the antineutron

The difference between the neutron and antineutron comes mainly from their quark content. The quark types are opposite in the antiparticle. This difference in quark content also has some consequences. For example, when a neutron and an antineutron interact, they can annihilate each other, resulting in a release of energy (unlike in the case of the \(\pi^{0}\), where there is no antiparticle counterpart). Another consequence of this difference in quark content is that their reactions with other particles will be different since the antineutron has different internal charges compared to the neutron.

Speculating on potential differences

Based on our understanding of neutrons and antineutrons, we can speculate on some possible differences. For instance, since their quark compositions are different, their weak decays could be different for neutron and antineutron producing different final-state particles. In conclusion, neutrons and antineutrons share similarities in mass, charge, and spin due to both being neutral particles. However, they have different quark compositions leading to distinct interactions and decays, making them different particles and not their own antiparticles.

Unlock Step-by-Step Solutions & Ace Your Exams!

Full Textbook Solutions
Get detailed explanations and key concepts
Unlimited Al creation
Al flashcards, explanations, exams and more...
Ads-free access
To over 500 millions flashcards
Money-back guarantee
We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Some neutral particles, like the \(\pi^{0}\), are their own antiparticles, but not the neutron. In what ways are \(n\) and \(\bar{n}\) the same? Speculate on how they might be different.

Short Answer

Step by step solution

Similarities between neutron and antineutron in terms of mass, charge, and spin

Quark content of the neutron and antineutron

Differences between the neutron and the antineutron

Speculating on potential differences

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Physics Textbooks

Conservation of Energy and Momentum

Torque and Rotational Motion

Classical Mechanics

Electromagnetism

Medical Physics

Kinematics Physics

Study anywhere. Anytime. Across all devices.