In particle physics, what is the name of the antiparticle that corresponds to the electron and has the same mass as an electron but a positive charge?

Introduction / Context:
This question tests your knowledge of fundamental particles and antiparticles in modern physics. According to quantum theory and relativistic physics, every particle has a corresponding antiparticle with the same mass and opposite charge, if it is charged. For the electron, which is a negatively charged lepton, the corresponding antiparticle plays an important role in processes such as pair production and beta plus decay. Recognising its correct name is part of basic particle physics general knowledge.

Given Data / Assumptions:

• The particle of interest is the electron, a light, negatively charged particle.
• The antiparticle must have the same mass as the electron but opposite (positive) charge.
• Options include positron, proton, alpha particles and beta particles.
• We assume standard definitions from particle physics.

Concept / Approach:
The antiparticle of the electron is called the positron. It has the same rest mass as the electron but carries a positive electric charge of the same magnitude. When an electron and a positron meet, they can annihilate, converting their mass into energy, usually in the form of gamma ray photons. Protons and alpha particles are much more massive than electrons and are not antiparticles of electrons. The term beta particles can refer to either electrons or positrons emitted in nuclear beta decay, but it does not uniquely name the antiparticle of the electron. Therefore, the correct and specific name is positron.

Step-by-Step Solution:
Step 1: Recall that an antiparticle has the same mass and spin as its corresponding particle but opposite charge and some other quantum numbers. Step 2: The electron has negative charge and small mass, so its antiparticle must have positive charge and the same small mass. Step 3: The particle with these properties is known as the positron. Step 4: Check the other options: the proton is positively charged but about 1836 times heavier than the electron, so it cannot be the electron antiparticle. Step 5: Alpha particles are helium nuclei composed of two protons and two neutrons, with much larger mass and charge +2e. Step 6: Beta particles is a generic term that can refer to fast electrons or positrons emitted in beta decay, not a specific name for the antiparticle. Step 7: Conclude that positron is the only correct, specific antiparticle of the electron.

Verification / Alternative check:
In many nuclear physics examples, beta plus decay is written as p → n + e^+ + ν, where e^+ denotes the positron. This notation makes it clear that e^+ is the positive counterpart of the electron e^-. Experiments involving pair production also show a gamma photon converting into an electron (e^-) and a positron (e^+), again highlighting the particle antiparticle pair. Such standard reactions confirm that the antiparticle of the electron is indeed the positron.

Why Other Options Are Wrong:
Proton is a much heavier positively charged particle that forms part of the nucleus; it is not the antiparticle of the electron. Alpha particles are helium nuclei with charge +2e and significant mass, completely different from a single electron or its antiparticle. Beta particles is a general term for fast electrons or positrons from radioactive decay, but it is not a unique name for the electron antiparticle.

Common Pitfalls:
Students sometimes confuse proton with positron because both are positively charged and their names sound similar. The key difference is that a proton is a baryon in the nucleus, while a positron is a lepton with the same mass as the electron. Remembering that the prefix posi in positron indicates positive electron helps distinguish it from proton. Paying attention to mass as well as charge is important when identifying antiparticles.

Final Answer:
The antiparticle corresponding to the electron is called the Positron.