# Quark Parton Model: Explaining Inelastic Scattering

• A
• Josh1079
In summary, the quark parton model assumes that inelastic lepton-hadron scattering can be explained by elastic lepton-hadron scattering. However, this does not seem to make sense to the author as elastic scattering would not lose energy.

#### Josh1079

Hi,

I've been studying the quark parton model recently and all seems fine at first. However, there's just one thing bugging me right now. So in the quark parton model it is assumed that inelastic lepton-hadron scattering can be explained by elastic lepton-hadron scattering, but how can it be? I've seen articles saying something like an incoherent sum of elastic scatterings and I suppose that's the answer, but I just don't get it how is it possible to sum a load of elastic scatterings into something inelastic? if each of them does not lose energy then why does the sum of them lose energy?

Might be a silly question but just bear with me please. Thanks.

If you scatter elastic from a parton then you give energy to this parton - if it gets enough energy this will lead to the creation of new particles from the hadron it was part of.

Josh1079 said:
So in the quark parton model it is assumed that inelastic lepton-hadron scattering can be explained by elastic lepton-hadron scattering
To me this sounds like you are talking about deep inelastic scattering, where you scatter a high energy lepton against a parton (not the entire hadron). This is a good approximation when the lepton is highly energetic in the hadron rest frame so that the partons can be considered free with respect to strong interactions. You then transfer a lot of energy to the parton, which upon further strong interactions leads to hadronisation and creation of new particles.

Hi mfb, Orodruin,

Thanks for the reply! I see that it is kind of a silly question. Haven't been thinking about scattering for too long. At that moment elastic scattering just occurred to me as saying "energy of lepton is conserved" which is, of course, totally false. Thank you guys so much for pointing that out!

## 1. What is the Quark Parton Model?

The Quark Parton Model is a theoretical framework used to explain the behavior of quarks and gluons inside a hadron during inelastic scattering processes. It was developed in the 1960s and 1970s by physicists Richard Feynman, Murray Gell-Mann, and others.

## 2. How does the Quark Parton Model explain inelastic scattering?

The Quark Parton Model proposes that the constituents of a hadron, such as protons and neutrons, are made up of smaller particles called quarks and gluons. During inelastic scattering, the quarks and gluons inside the hadron interact with the incident particle, causing a change in their momentum and energy. This model helps to explain the observed scattering patterns and allows for the calculation of cross-sections and other properties of the scattering process.

## 3. What is the significance of the Quark Parton Model?

The Quark Parton Model is significant because it provides a fundamental understanding of the structure of hadrons and how they interact with other particles. It also forms the basis for the theory of quantum chromodynamics (QCD), which describes the strong nuclear force that binds quarks together. The model has been extensively tested and has been successful in explaining a wide range of experimental data.

## 4. Are there any limitations to the Quark Parton Model?

While the Quark Parton Model has been successful in explaining many aspects of inelastic scattering, it has some limitations. For example, it does not take into account the effects of quark confinement, which is a phenomenon where quarks cannot exist as isolated particles but are always bound together in hadrons. Additionally, the model does not fully address the behavior of particles at very high energies or in extreme conditions, such as in a quark-gluon plasma.

## 5. How does the Quark Parton Model relate to the Standard Model of particle physics?

The Quark Parton Model is a key component of the Standard Model of particle physics, which is the prevailing theory that describes the fundamental particles and their interactions. It specifically falls under the category of the strong nuclear force, one of the four fundamental forces in the Standard Model. The model has been incorporated into the Standard Model and has played a crucial role in our understanding of the subatomic world.