What IS a Cross Section pt. 2: Differential Cross Sections in Particle Physics

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  • Опубліковано 12 лис 2024

КОМЕНТАРІ • 211

  • @Leo-ex6bl
    @Leo-ex6bl 4 роки тому +57

    Small correction: The Higgs mass at ≈125GeV was not predicted by the Standard Model but is actually a fit result from the measurement data. There were some contraints on the Higgs mass based on other experiments but no actual prediction.

    • @AndrewDotsonvideos
      @AndrewDotsonvideos  4 роки тому +7

      Thanks for pointing that out!

    • @goktrenks
      @goktrenks 4 роки тому

      OP,what do you mean by "fit result"?Sorry,1st yr undergrad here

    • @ozymandias3303
      @ozymandias3303 4 роки тому +6

      goktrenks when they draw invariant mass distribution(aka plot) the saw some pike. This pike in mass corresponds to Higgs mass. In order to get this value they get some functions with parameters and tried to fit aka find values of parameters so that function looks like original distribution. One of the parameters of this fit function corresponds to the mass of the Higgs. en.wikipedia.org/wiki/Curve_fitting some wiki article about that
      P.s. sorry English isn’t my native language.

    • @goktrenks
      @goktrenks 4 роки тому

      @@ozymandias3303 Thanks!

  • @maureendotson4634
    @maureendotson4634 4 роки тому +229

    What’s going on smart son! Another great video ~ Mom💕

    • @Chase-b5t
      @Chase-b5t 4 роки тому +12

      Hi Mrs. Dotson! 👋 Just wanted to comment that you are a great mother for following and supporting your son's videos so much. I wish my mom cared about my stuff like that 😅

    • @laRa-zg8ys
      @laRa-zg8ys 4 роки тому +2

      kindly read everything from this site to know about the absolute truth islam -onereason.org/

    • @jaykay2218
      @jaykay2218 4 роки тому +8

      @@laRa-zg8ys fuck off please

    • @rezrez4901
      @rezrez4901 4 роки тому +6

      @@laRa-zg8ys No one whats to, fuck off

    • @michaelg5932
      @michaelg5932 4 роки тому +5

      @@laRa-zg8ys this is physics, not religion, so as the 2 people above me said, get ur ass outa here

  • @samilamby
    @samilamby 4 роки тому +98

    “If you think this graph looks gross, just imagine calculating it” - I felt that on a deep level

  • @NearlyPerfectGames
    @NearlyPerfectGames 4 роки тому +47

    Andrew you probably won’t see this but I just started my undergrad as a physics major in part because of you. I’m scared but excited wish me luck!

    • @Smapiecus
      @Smapiecus 4 роки тому +12

      Yoo same dude! Good luck! I hope you do well and enjoy it.

    • @AndrewDotsonvideos
      @AndrewDotsonvideos  4 роки тому +18

      Wow best of luck!

    • @kensmusic1134
      @kensmusic1134 4 роки тому +6

      haha another string theory enthusiast...

    • @jumbojimbo706
      @jumbojimbo706 4 роки тому +4

      I’m doing physics with astrophysics and I’m dead scared

    • @deathstroke8639
      @deathstroke8639 4 роки тому +2

      Honestly. I'm lowkey deciding to switch to physics because of a couple reasons but his teachings on physics is definitely one of them

  • @xbulletboi563
    @xbulletboi563 4 роки тому +108

    i dont even understand this and i enjoy it.

    • @thequark222
      @thequark222 4 роки тому +4

      I can relate....

    • @mathnasiumalumni7608
      @mathnasiumalumni7608 4 роки тому

      Polish hotdogs?

    • @ramansb8924
      @ramansb8924 4 роки тому

      I feel the same 🔥😂🔥

    • @xCaleb
      @xCaleb 4 роки тому

      xBulletBoi bro same haha. I’m just a computer engineer going for a comp sci masters 🤷‍♂️

    • @Justin-wd2vy
      @Justin-wd2vy 4 роки тому

      Keep at it. Eventually you will.

  • @mackenzie1380
    @mackenzie1380 4 роки тому +1

    some days when i’m sad i’ll binge your videos because i love physics, and then i realize i barely know what you’re talking about. but every time i hear, “what’s goin on smart people” i think, “he...he said i’m smart🥺”

  • @stpeter1241
    @stpeter1241 4 роки тому +8

    I just want to comment to Andrew that he inspired me to persue physics. You are my physics hero, thank you, you mean the world to me.
    Never stop posting you inspire more people than you could know!

  • @RC32Smiths01
    @RC32Smiths01 4 роки тому +14

    Hey man, for me it's such a great feeling to learn about this at an early stage. Great to see you back with the lessons!

  • @josev9059
    @josev9059 4 роки тому +7

    Dude, I just came out of my QM1 class and didn’t get this, you’re a hero

  • @JoeLewisFan
    @JoeLewisFan 4 роки тому

    I feel like u make these types of videos not only to let others needing help with these things but to also understand it further urself. Good job, keep it up

  • @lewisleslie2821
    @lewisleslie2821 4 роки тому +2

    You’re so good at making understandable analogies, relating abstract mathematical ideas to physical interpretations. Thats a valuable skill

  • @professorfinesser4322
    @professorfinesser4322 4 роки тому

    im so thankful people like you exist, we need y'all

  • @Erll_
    @Erll_ 4 роки тому +3

    Hi Andrew!
    I had recently taken particle physics before I graduated as an elective. The cross-sections part had me very confused but you explained it a lot better than my teacher!

    • @waqarali9166
      @waqarali9166 Рік тому

      imagine you are from sub continent and studying particle physics in Italy and your teacher have that accent which is as hard to understand as the cross section. :(

  • @alexblake8306
    @alexblake8306 4 роки тому +2

    I'm in Physics 2 right now and the fact that I actually know a couple of things you're saying and understand it is amazing. Even if it's just the simple pieces for this video.

  • @shawcampbell7715
    @shawcampbell7715 4 роки тому +2

    I can't wait till I come back to these videos after 2 years at uni and understanding them. Gonna be so satisfying

  • @sombal1999
    @sombal1999 4 роки тому +67

    4:22" allow me to demonstrate" I thought he was gonna throw the cat on the wall

  • @josewui414
    @josewui414 4 роки тому +4

    This is priceless knowledge for free. Thank you Papa Dotson.

  • @glass_parton
    @glass_parton 4 роки тому +1

    Thanks for the video! This has been my research the last two years (Drell-Yan differential cross section for CMS); I'm glad to finally learn it!

    • @AndrewDotsonvideos
      @AndrewDotsonvideos  4 роки тому +1

      Oh yeah I'm sure you have dreams (or nightmares) of them then!

  • @mohammadtarshihi364
    @mohammadtarshihi364 4 роки тому +2

    Finally! Andrew uploads and it’s cross section part 2

  • @lucidmath5481
    @lucidmath5481 2 роки тому

    andrews humour is the most underrated thing on the internet

  • @noha6926
    @noha6926 4 роки тому +1

    Hey Andrew I just fell on your channel and it's just so amazing!! Your explications are so clear it's so nice. With my 15 years old (16 tomorrow haha) and the fact that I'm not an English native speaker at all, I can't understand everything for sure, but I'm still so happy to learn about science and physics so thanks from Québec for your wonderful work!

  • @jigyasanigam5582
    @jigyasanigam5582 4 роки тому +1

    I discovered this channel today.. you are awesome! So nice to have found this, very early on in my PhD, it's a great support! :)

  • @sheennina1234
    @sheennina1234 4 роки тому +2

    As a physics major, i'm glad i found this channel, it makes me normal i like it 😂

  • @mrxcrdz4262
    @mrxcrdz4262 4 роки тому

    Hey Andrew,
    I was studying this for my thesis (just getting started) and I didn't understand anything until I saw your videos. It's amazing how you explain it and now I'm even more excited to learn. Thanks

  • @cristhianm
    @cristhianm 4 роки тому +1

    I don't understand any of this but I enjoy Andrew's talking and the way he explains concepts. To be honest I'm still subscribed to help out our boy here.

  • @robertsteinbeiss8478
    @robertsteinbeiss8478 4 роки тому +1

    Early thunbs up for your high aims presented as, "let's go, can't be that difficult"
    Would love to see future studends coming to your lectures and say, "Professor, we saw your historic lectures!"

  • @captaincarcass8996
    @captaincarcass8996 4 роки тому +2

    your channel made me really interested in physics and potentially pursuing it as a career, very nice content. keep it up

  • @thebighadron
    @thebighadron 4 роки тому +2

    Awesome video, Yep would be great if you can make a follow up video to actually calculate the probabilities using the Feynman rules etc

  • @theoreticalphysicist9241
    @theoreticalphysicist9241 4 роки тому +2

    I’ve missed you dr Dotson that video was amazing. I would love to see the same video but in the math version.

  • @wardippy226
    @wardippy226 4 роки тому

    I go to high school at the moment (and i want to study physics at the unoversity) but deep down i know that some day when i am going to struggle because of my classes and because i won't understand it, your videos are going to help me. Thank you.

  • @MrCaptainFrosty
    @MrCaptainFrosty 4 роки тому +3

    People always ask WHAT is a cross section, never HOW is a cross section. Good video Andrew!

  • @GaryGP40
    @GaryGP40 4 роки тому +1

    Nice presentation. I like how you show the creation of the Higgs boson! I, for one, would love to see you work out the math as well, that would be an interesting way to learn this! Thanks again for another great video!

  • @sergniko
    @sergniko 4 роки тому +1

    Any video from you is good. Bring some more!

  • @andreareinhardsdottir5275
    @andreareinhardsdottir5275 4 роки тому +3

    Omg welcome back! You haven't made videos in over a month!!

  • @viniciusf.linhares1416
    @viniciusf.linhares1416 4 роки тому +1

    Man im studying for a internship in introductory pertubative QCD, your explanation was very usefull!
    Another videos in this direction would be nicelly welcoming.

  • @CCequalPi
    @CCequalPi 4 роки тому +1

    Id love to see this. Havent gotten past basic particle physics so itd be cool to see some qcd and other stuff from the standard model

  • @ashwinvishwakarma2531
    @ashwinvishwakarma2531 3 роки тому

    I would really like to see more on differential cross sections and how you calculate them

  • @dozzco2827
    @dozzco2827 4 роки тому +1

    Great video! Great to learn about important aspects of particle and nuclear physics 👍

  • @NikolajKuntner
    @NikolajKuntner 4 роки тому +2

    This was great, keep making more of those.

  • @ShadowZZZ
    @ShadowZZZ 4 роки тому +2

    particle physics is so difficult. great job explaining tho, I really liked the experimental data proving the higgs bozon towards the end. seeing the calculations I wouldnt understand much probably, but it could be entertaining.

  • @abhishekkp7121
    @abhishekkp7121 4 роки тому

    Now i feel happy.
    Its been a long time.
    Awesome video.

  • @chenicavhey
    @chenicavhey 3 роки тому

    I'm doing my probset in QM right now... thank you for this video

  • @DietterichLabs
    @DietterichLabs 4 роки тому +12

    I'm interested in seeing how you would present the math

    • @AndrewDotsonvideos
      @AndrewDotsonvideos  4 роки тому +3

      It'll definitely be a challenge to present it in a way that's not just vomiting P&S onto the whiteboard but I have some ideas.

  • @shmoogador5979
    @shmoogador5979 4 роки тому +1

    Andrew have you considered being a professor? Your videos are amazingly intuitive even for someone with a limited physics background.

  • @zae9359
    @zae9359 4 роки тому +1

    This is what I'm doing in my research right now! Just finished writing a program to calculate cross sections :)

    • @AndrewDotsonvideos
      @AndrewDotsonvideos  4 роки тому +1

      Awesome! For what process?

    • @zae9359
      @zae9359 4 роки тому

      @@AndrewDotsonvideos Inclusive electron scattering! I got a research assistantship from JLab this summer so I've only just started but it's been great so far. I'm looking at it at high Bjorken x values with different momentum and targets to study the electrons after scattering.

    • @AndrewDotsonvideos
      @AndrewDotsonvideos  4 роки тому

      Gwen nice! I had a couple internships there as well. Who are you working with?

    • @zae9359
      @zae9359 4 роки тому

      Andrew Dotson I’m working with the Niculescus! They’re my research advisors at my university. I was supposed to have a SULI internship this past summer but it got moved to next summer so we’ll see who I work with for that!

  • @Wolkenphoenix
    @Wolkenphoenix 4 роки тому +1

    Huh, I ended up watching the second video today already :D Nice video, looking forward to the next one :)

  • @tribananas
    @tribananas 4 роки тому +1

    This was very insightful. (Spoiler alert) The Higgs was a really cool example. Thanks, Andrew!

  • @name8166
    @name8166 4 роки тому +1

    Hey, ANDREW PLEASE ANSWER TWO QUESTIONS
    1) Can you make video lectures on Optical Physics??
    1) Are Walter Lewin classical Mechanics, Waves and vibrations, Electricity and Magnetism lectures enough for co-responding topics in Bachelor level Physics??

  • @laurencemcdonald9154
    @laurencemcdonald9154 3 роки тому

    Hey, great helpful video. Did you do a video on calculating the cross section for this type of decay? Would be super helpful for my thesis to further my understanding (specifically the gluon fusion resulting in the Higgs creation)

  • @presqpuperze9771
    @presqpuperze9771 4 роки тому +4

    "Just imagine calculating it" - Well, considering I am working on my bachelor's thesis on numeric stability of multi-loop integrals, I felt that.

  • @physicsforever4793
    @physicsforever4793 4 роки тому +18

    PLZ REPLY ANDREW
    Hey andrew, we want to invite you as a guest for our virtual conference.
    The other speakers in this conference are
    Alexi Starobinsky, Cosmologist, Kavli prize winner 2014.
    Jorge Pullin, Theoretical Physicist.
    Dan Hooper, Cosmologist.
    May I know how to contact you?

    • @AndrewDotsonvideos
      @AndrewDotsonvideos  4 роки тому +11

      Hi,
      my email is available on my about section. I haven't checked it in a couple weeks because I've been working on other projects, but now I have some time freed up.

    • @physicsforever4793
      @physicsforever4793 4 роки тому +10

      @@AndrewDotsonvideos Hey, thank you for replying. I have sent you an email . In fact I have sent you a couple of times. The latest one would be the invitation for the conference. You must have received it from this email (physicsforever242@gmail.com)

    • @toxxikanshul
      @toxxikanshul 4 роки тому +1

      @physics forever, im a research grad in cosmology. If i can also join you guys - ( anshul.verma690@gmail.com) . Ty

    • @physicsforever4793
      @physicsforever4793 4 роки тому +1

      @@toxxikanshul OK, we have sent you an email

    • @mokopa
      @mokopa 4 роки тому +1

      Eew Krauss is on the list

  • @xTechnoWOW
    @xTechnoWOW 4 роки тому +1

    Thanks for these great videos!

  • @gibbs-13
    @gibbs-13 4 роки тому +1

    Please give more lectures of Quantum Field Theory

  • @micahsell1
    @micahsell1 4 роки тому

    I would like to see a video about answering the question "Do you have to go to a prestigeous university to study physics?" More specifically to have the resources you need to become a successful physicist.

  • @duckandpug8693
    @duckandpug8693 4 роки тому +1

    Love you Andrew, you keep me going and all your subscribers, hope you life keeps getting better (((((( : ♥️🎃

  • @zakirreshi6737
    @zakirreshi6737 3 роки тому

    Thanks for great video and also for references

  • @vedantkashyap5703
    @vedantkashyap5703 4 роки тому +1

    Yes please the maths behind differential cross sections.... I'm studying field theory and particle physics this semester.

  • @kenpodolak
    @kenpodolak 4 роки тому

    Well done. Very good overview!

  • @gg-bn4gv
    @gg-bn4gv 3 роки тому

    yess please do a video with the math!

  • @riddhiyadav2532
    @riddhiyadav2532 4 роки тому +1

    I am going to apply for my pg program in particle physics soon🙈 And I recently found your channel, you are LITERALLY what I aspire to be. Your videos just gave me an extra boost of confidence that yeaahh this is what I wanna do!! Thank you for your efforts ❤️
    Also... Can you suggest me few topics I should have a good grasp over before starting with my pg in particle or theoretical physics? Both in maths and physics.

  • @humanfrommars5832
    @humanfrommars5832 4 роки тому +1

    Hlo Andrew. How often do u think that your interest fluctuates from physics

  • @hamiltonian450
    @hamiltonian450 4 роки тому +1

    also AnDROw what was the list of bad physics textbooks for? I was watin so eagerly for a vid on that or something..

  • @harry-ho9ti
    @harry-ho9ti 4 роки тому +1

    Pls do a lecture on Dirac Hole theory and Dirac theory in electromagnetic field.

  • @tp_2301
    @tp_2301 3 роки тому

    Is there going to be a part 3? I really enjoyed 1 and 2

  • @Supercatzs
    @Supercatzs 3 роки тому

    Get a load of THIS guy

  • @sakshamkshatri9649
    @sakshamkshatri9649 4 роки тому +4

    never clicked so fast !!

  • @DylanCVlogTV
    @DylanCVlogTV 4 роки тому +1

    Wouldn't the 125 target energy be more akin to heavy element creation or a proton/neutron isotope instead of a fundamental particle given that it's clearly unstable at that energy density?
    The Higgs energy state was a wonderful discovery, but I've always questioned it's true nature as a defined particle instead of a combination of quarks coming unglued through decay.

    • @pcb1852
      @pcb1852 4 роки тому

      It cannot simply be something like a heavy nucleus because it has baryon number zero. But you are right, it might be not a "fundamental particle" (however that would be exactly defined in a quantum field theory), there are several "composite Higgs" theories in the literature. In the Standard Model, the Higgs is a fundamental field in the Lagrangian, but the S.M. is certainly not the last word on this...

  • @joshuapasa4229
    @joshuapasa4229 4 роки тому +1

    Is there any way of knowing the out come of a particle interaction, or is the outcome also probabilistic?

    • @AndrewDotsonvideos
      @AndrewDotsonvideos  4 роки тому +1

      That is the cross section. sigma(2p-> 4l) is a measurement of the probability that the outcome will be 4 leptons if two protons go in.

  • @alex_romancino
    @alex_romancino 3 роки тому

    Please make a sequel!

  • @sverrehestholm723
    @sverrehestholm723 4 роки тому

    I love the lecture videos!

  • @maxwellsequation4887
    @maxwellsequation4887 4 роки тому

    Good day, Doctor Dotson

  • @sakshamsharma4184
    @sakshamsharma4184 4 роки тому +12

    Hi andrew i am your big fan
    From india
    I also want to pursue carrier in physics

  • @Nickx73
    @Nickx73 4 роки тому +1

    SHOW US THE MATH! :D Theoretical physicist here! :D

  • @macsentiffany618
    @macsentiffany618 4 роки тому +1

    Hi bro, big fan of your shit, and got a bit of a request for u. I am 18 and going to study pure physics next year, could you make a vid or two on calculus in physics for those of us who found pre uni physics and maths a doddle but struggle with stuff like this because we just haven't covered the material yet. Thanks

  • @karnvirbhangu334
    @karnvirbhangu334 4 роки тому +1

    Hello sir, I sent an email to you regarding the x-ray absorption cross section and fermi's golden rule could you please read through the email and make a video regarding that please.

  • @brooklynfbailey
    @brooklynfbailey 4 роки тому +1

    what are you're social media handles?

  • @gartenstuhl2396
    @gartenstuhl2396 3 роки тому

    As a medical engineer with no experience in quantum physics I came to better understand Compton scattering and the Klein-Nishina differential cross section and left with a headache.

  • @yenyelinito
    @yenyelinito 4 роки тому +2

    I’m a freshman, I don’t understand anything yet I still enjoy HAHA

  • @addy7464
    @addy7464 4 роки тому +1

    All you physics guys there does anyone know what d(rho)/4pi represent?

  • @markos1623
    @markos1623 4 роки тому

    I finally get it! Thanks 👍

  • @youtubegaming3281
    @youtubegaming3281 4 роки тому +4

    Make special theory of relativity by the way I love physics and you

    • @Kraflyn
      @Kraflyn 4 роки тому +1

      yeah, special theory for dummies, light clocks and space ships! no matrices. I second this! Peeps love those.

  • @ParthGChannel
    @ParthGChannel 4 роки тому +1

    Once you go quantum you never go back

  • @pugazharasuad
    @pugazharasuad 4 роки тому +1

    How it's going

  • @Kraflyn
    @Kraflyn 4 роки тому

    what do you think about the QED renormalization?

    • @AndrewDotsonvideos
      @AndrewDotsonvideos  4 роки тому +1

      That’s the only renormalized theory that makes sense to me conceptually

    • @Kraflyn
      @Kraflyn 4 роки тому

      @@AndrewDotsonvideos Huh, how exactly does it make sense? ... :D "Look, it doesn't work, everything is singular. Oh look, if we use totally unrealistic parameters such as mass and charge, we get the regular answer!" The only "real" magic I see here is that this reparametrization works in every single case with the same reparametrized mass and charge. The "lets try different mass" thing is the voodoo part of magic :D And yes, this is then applied to everything, such as quarks as well. Yes, QED was kind of proven when the screening of charge was measured through fine structure constant... but.. it's all circular... of course it was "proven", all the parameters were chosen so to fit the experimental results, all but one experimental result -- the mass and charge of a free particle :D So... it proves nothing... Or, the asymptotic freedom in QCD, same thing, same problem... I don't know... It stinks. Chime in with your thoughts please if you will. Been reading about it a lot for last few decades, nothing makes it seem any brighter to me... Regards! o/

  • @physicsperadox7849
    @physicsperadox7849 4 роки тому +1

    Bro i wana do p.hd in QM ,what do u think any pro tip

  • @alexavinagre470
    @alexavinagre470 4 роки тому +2

    Where's Kelly?

  • @andreareinhardsdottir5275
    @andreareinhardsdottir5275 4 роки тому +2

    Can you finish up your Phd and become a physics professor in Iceland?? (It pays well)

  • @sameerkooliyat3044
    @sameerkooliyat3044 4 роки тому

    When is the graphic tablet coming in?

  • @ritujithmanoj2133
    @ritujithmanoj2133 4 роки тому +3

    Is this related to differential calculus, cos that's what I only know

    • @Kraflyn
      @Kraflyn 4 роки тому

      a bit, yeah... :3

  • @andresfelipecanobotero8814
    @andresfelipecanobotero8814 4 роки тому +1

    Why is mass frame independent? I though that as a particle approaches c its mass goes up to inf? Or is that just 1/0 math nonesense?

    • @AndrewDotsonvideos
      @AndrewDotsonvideos  4 роки тому

      No. Mass never depends on your reference frame. Inertia increases as your speed increases, but that's because relativity shows that total energy contributes to the inertia of the system, not just the mass.

  • @iveharzing
    @iveharzing 4 роки тому +4

    This is all very interesting, but I'm still confused what the Differential Cross Section actually means.

    • @Kraflyn
      @Kraflyn 4 роки тому +1

      watch part 1

    • @AndrewDotsonvideos
      @AndrewDotsonvideos  4 роки тому +1

      It’s the probability of measuring a certain process within a certain range of a kinematic variable such as solid angle or energy.

    • @DaytonaStation
      @DaytonaStation 3 роки тому

      Andrew is great but he does not have control of DCS YET...neither do I.

  • @stevenhtut3388
    @stevenhtut3388 4 роки тому +2

    0:19..yes quite quite

  • @juancarlosdominguezsolis.4665
    @juancarlosdominguezsolis.4665 4 роки тому +1

    please do a video of lie groups in standar model please please please and i really love your videos (i have 16teen)

  • @brettsetera7075
    @brettsetera7075 4 роки тому

    He's gone full professor mode: "Just read Taylor " haha

  • @edwardwhite8253
    @edwardwhite8253 4 роки тому +2

    *me, who just got into college 2 weeks ago and just begun learning gauss's law watching this video* : ah yes electricity, i know a lot about electricity and charges and fluxes

  • @user-en5vj6vr2u
    @user-en5vj6vr2u 4 роки тому +3

    "Yeah I understand what's going on"

  • @phenixorbitall3917
    @phenixorbitall3917 4 місяці тому

    Nice

  • @abrahamnasr5397
    @abrahamnasr5397 4 роки тому

    I agree

  • @AnshishRay
    @AnshishRay 4 роки тому +1

    Andrew could you plz check your email. I have a question which i am not able to understand. It will be about geometry of spherical surfaces!!

  • @iamjustapoorboii598
    @iamjustapoorboii598 4 роки тому

    When he says lemme show u in the schrodinger's cat part while holding the cat i really thought he is going to yeet his cat on to the board