Yes, it is feasible to publish a paper without a PhD; PhD students do it all the time. Papers are intended to be judged based on what they say, not who said it. Such papers are frequently written by graduate or undergraduate students, for example. However, these papers usually lack in rigor and fail to impress other scientists.
The main reason why people with no scientific background can't publish papers is that there are just too many details involved in making something sound. Only people with some experience of the literature could have enough knowledge to make their ideas sound original and useful. They would also need to plan their work out carefully, since they wouldn't be able to simply start writing down their ideas.
In conclusion, it is feasible to publish a paper without a PhD but it is difficult for someone without any relevant experience to do so.
Submitting an academic article for publication (and maybe having it approved) requires no credentials. You don't need a PhD or even to have attended college. However, if you can find out how to do it without a PhD, your lack of one will not be an impediment. An MS is enough.
An MA will get you published in some journals. But whether a PhD or not, you need to know how to write up what you've done so that it makes sense to other people. And whether it's a PhD or not, you need to do this based on actual research rather than just thinking about it all the time.
Once you've written something up that you think would be interesting to other people, you need to send it to a journal that they might be interested in. Most universities have some sort of library that will let you look up journals related to your field of study. They will tell you if there are any peer review processes that need to be completed before your work can be published, and if so, how these are done. If there aren't any formal review processes, then anyone with access to the journal can read your work once it has been submitted.
It is possible to get unpublished papers cited, but only if those who have read them go on to write their own versions of them.
Most PhD aspirants have no prior publishing history when they apply. Having some publications is a huge benefit in general, whereas not having one is typical. In fact, many people who finish their degrees never publish anything at all.
However, it is certainly possible to gain admission into a good doctoral program with no publications. You will need to make sure that your research is well thought out and there are relevant topics within the field so it is accepted. Generally speaking, if you can convince the committee that you are able to write a successful dissertation based on our limited knowledge about issues in your field, then they should allow you to proceed.
Publishing papers is not required for a PhD degree. In fact, many students do not publish at all during their studies. The only way to know if you are ready to defend your thesis is by applying to programs. If you cannot find any information about published work or evidence of research activity other than the application form, then assume that none exists and move on to another topic.
It is also worth mentioning that most universities require you to publish before you can be awarded your PhD. So even if you are able to get through the admission process with no publications, usually you would not be allowed to graduate.
The simple answer is no. Publications are not necessary for PhD applicants. The lengthier answer is that the admissions committee is looking for evidence that you have the ability to be an exceptional researcher. While publications are one method to demonstrate this, they are not the only way to demonstrate excellent research abilities. For example, if you develop some new technology that is used by others in your field, this would also be considered good evidence of your research skills.
Ultimately, your application will be judged on its own merits. If you can clearly and concisely describe your research interests and how they relate to the department's needs, then you will have a strong application.