/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 48 Which of the following reactions... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 30: Problem 48

Which of the following reactions obey the conservation of baryon number? (a) \(\mathrm{p}+\mathrm{p} \rightarrow \mathrm{p}+\mathrm{e}^{+},(\mathrm{b}) \mathrm{p}+\mathrm{n} \rightarrow 2 \mathrm{e}^{+}+\mathrm{e}^{-}\)(c) \(\mathrm{p} \rightarrow \mathrm{n}+\mathrm{e}^{-}+\overline{\nu}_{\mathrm{c}},(\mathrm{d}) \mathrm{p}+\overline{\mathrm{p}} \rightarrow 2 \gamma\)

Short Answer

Expert verified
Reactions (c) and (d) obey conservation of baryon number.

Step by step solution

01

Understand Conservation of Baryon Number

Baryon number is a conserved quantity in particle reactions. Each baryon (such as a proton or neutron) has a baryon number of +1, while antibaryons (such as antiprotons) have a baryon number of -1. All other particles, like electrons, positrons, and photons, have a baryon number of 0. A reaction obeys baryon number conservation if the total baryon number before the reaction equals the total baryon number after the reaction.
02

Analyze Reaction (a)

For the reaction \( \mathrm{p} + \mathrm{p} \rightarrow \mathrm{p} + \mathrm{e}^{+} \),- Initial baryon number: \(1 + 1 = 2\) (from protons).- Final baryon number: \(1 + 0 = 1\) (from one proton and one positron).This reaction does not obey baryon number conservation since the baryon numbers do not match.
03

Analyze Reaction (b)

For the reaction \( \mathrm{p} + \mathrm{n} \rightarrow 2 \mathrm{e}^{+} + \mathrm{e}^{-} \),- Initial baryon number: \(1 + 1 = 2\) (from proton and neutron).- Final baryon number: \(0 + 0 + 0 = 0\) (from positrons and electron).This reaction does not obey baryon number conservation since the numbers do not match.
04

Analyze Reaction (c)

For the reaction \( \mathrm{p} \rightarrow \mathrm{n} + \mathrm{e}^{-} + \overline{u}_{\mathrm{c}} \),- Initial baryon number: \(1\) (from proton).- Final baryon number: \(1 + 0 + 0 = 1\) (from neutron, electron, and antineutrino).This reaction obeys baryon number conservation as the numbers are equal.
05

Analyze Reaction (d)

For the reaction \( \mathrm{p} + \overline{\mathrm{p}} \rightarrow 2 \gamma \),- Initial baryon number: \(1 - 1 = 0\) (from proton and antiproton).- Final baryon number: \(0\) (from two photons).This reaction obeys baryon number conservation.

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.

Over 30 million students worldwide already upgrade their learning with 91影视!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Particle Reactions
Particle reactions are processes where particles interact and transform into different particles. They can involve the transformation or interaction of particles like protons, neutrons, electrons, and their antiparticles. When particle reactions occur, it's essential to ensure that certain quantities are conserved. These conserved quantities include energy, charge, and baryon number. Baryons, such as protons and neutrons, are key players in these interactions. Understanding the conservation laws that govern these interactions helps physicists predict whether a reaction can occur under normal conditions.
Baryons and Antibaryons
In the realm of particle physics, baryons are particles composed of three quarks, and they include protons and neutrons. Each baryon has a baryon number of +1. On the flip side, antibaryons are composed of three antiquarks and have a baryon number of -1. Antiprotons and antineutrons fall into this category. Baryons and antibaryons can only interact in ways that maintain the overall baryon number in the universe. This approach ensures stability and consistency in the laws of physics. While baryons and antibaryons are subject to other forces and interactions, the baryon number conservation remains a cornerstone rule in determining the viability of particle reactions.
Baryon Number Conservation
The conservation of baryon number is a fundamental principle in particle physics. It dictates that the total baryon number before and after a particle reaction must remain the same. This means if you have two baryons before a reaction, you must still account for them in some form after the reaction. Assessing reactions for baryon number conservation helps in identifying feasible reactions. For example, in a reaction where a proton and a neutron combine, the total baryon number starts at 2. If the reaction's products do not have a combined baryon number of 2, then the conservation of baryon number is violated, making the reaction non-viable in nature without outside interference.
Physics Problem Solving
Solving problems in physics involves more than applying formulas; it requires a firm grasp of concepts. In analyzing particle reactions, one begins by identifying the particles involved and calculating their total baryon number. Next, observe the reaction products and reassess the total baryon number. By comparing these values, students can determine if a reaction is possible. This process develops critical thinking and reinforces understanding of particle interactions. Whether in academic settings or real-world applications, a structured approach to physics problems ensures accurate solutions and enhances learning.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

The nucleus \(_{8}^{15} \mathrm{O}\) has a half-life of 2.0 min. \(_{8}^{19}\mathrm{O}\) has a half-life of about 0.5 min. (a) If, at some, time, a sample contains equal amounts of \(_{8}^{15} \mathrm{O}\) and \(_{8}^{19} \mathrm{O},\) what is the ratio of \(_{8}^{15} \mathrm{O}\) to \(_{8}^{19} \mathrm{O}\) after 2.0 min? (b) After 10.0 min?

A proton and an antiproton annihilate, producing two photons. Find the energy, frequency, and wavelength of each photon emitted (a) if the initial kinetic energies of the proton and antiproton are negligible and (b) if each particle has an initial kinetic energy of 830 \(\mathrm{MeV} .\)

We are stardust. In \(1952,\) spectral lines of the element technetium-99 \(\left(^{99} \mathrm{Tc}\right)\) were discovered in a red-giant star. Red giants are very old stars, often around 10 billion years old, and near the end of their lives. Technetium has \(n o\) stable isotopes, and the half life of \(^{99} \mathrm{Tc}\) is \(200,000\) years. (a) For how many half-lives has the \(^{99} \mathrm{Tc}\) been in the red-giant star if its age is 10 billion years? (b) What fraction of the original \(^{99} \mathrm{Tc}\) would be left at the end of that time? This discovery was extremely important because it provided convincing evidence for the theory (now essentially known to be true) that most of the atoms heavier than hydrogen and helium were made inside of stars by thermonuclear fusion and other nuclear processes. If the Tc had been part of the star since it was born, the amount remaining after 10 billion years would have been so minute that it would not have been detectable. This knowledge is what led the late astronomer Carl Sagan to proclaim that "we are stardust."

Show that the net result of the proton-proton fusion chain that occurs inside our sun can be summarized as $$6 \mathrm{p}^{+} \rightarrow_{2}^{4} \mathrm{He}+2 \mathrm{p}^{+}+2 \beta^{+}+2 \gamma+2 \nu_{\mathrm{e}}$$

The measured energy width of the \(\phi\) meson is 4.0 \(\mathrm{MeV}\) and its mass is 1020 \(\mathrm{MeV} / c^{2} .\) Using the uncertainty principle (in the form \(\Delta E \Delta t \geq h / 2 \pi ),\) estimate the lifetime of the \(\phi\) meson.
See all solutions

Recommended explanations on Physics Textbooks

Physics of Motion

Read Explanation

Atoms and Radioactivity

Read Explanation

Space Physics

Read Explanation

Magnetism

Read Explanation

Wave Optics

Read Explanation

Magnetism and Electromagnetic Induction

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.