I'm a physics-majored undergrad student studying in the U.S. and I'm looking for some graduate programs in the UK. In my university, most graduate students are directly enrolled in the Ph.D. programs after completing their Bachelor's degree, but I'm not sure if this works the same in the UK. If I will eventually pursue a Ph.D. degree, do I need to first apply for the MSc programs? Is it possible to directly get into a doctorate program? Thanks!
You can certainly start a physics PhD in the UK with just a BSc. Your application would be strengthened if you have a final year dissertation as part of your degree (typically 5000-8000 words) as these are standard in the UK and help students get a bit of research experience.
However, the majority of applicants to UK physics PhDs will have what's called an "integrated Master's", usually designated as MPhys. These are four year degrees where you do not graduate after three years with a BSc but go straight into a fourth year, which will comprise more specialised courses and a longer dissertation project. They're not quite as research heavy as an MRes or MPhil, which are purely research-based Master's. Their closest equivalent is BSc+MSc.
I recommend you apply to PhDs and Master's at the same time -- you may well be successful with your PhD applications but if not, you certainly will with your Master's. However, you will still have to apply for PhDs once you have started your MSc -- you cannot upgrade or convert your enrollment to PhD once you are in (this may be possible with an MRes/MPhil but you would need to check the individual university's regulations).
Note that funding for an MSc must be found by the student -- you will not be able to earn money as a TA as is common in the US. UK students can take out a postgraduate loan from the government but I don't know if this is available to international students. Bear in mind that physics PhDs are competitive and you should apply to ten or more universities to increase your chances of acceptance. Good luck!
Most go straight from a Bachelor's degree (and that would be considered quite normal). Some have a Master's degree (which wouldn't be thought of as a negative) and an increasing number enrol in combined MRes/MPhil + PhD programmes (which involve doing a Master's before progressing to a PhD at the same university in the same field).