Welcome to TeX.SE. The font is in the Times Roman family. Do you have access to the pdf file? If so, do look under File -> Properties -> Fonts to access the font-related information directly.
– MicoDec 23 '18 at 19:48
I did not claim that the newtxmath math font package was in use. There are many, many Times Roman clones out there. Anyway, do you have access to the pdf file?
– MicoDec 23 '18 at 19:59
@erika21148: run in a terminal pdffonts <file>.pdf and you'll get a list of the used fonts.
– Dec 23 '18 at 20:48
I fear that this is not even LaTeX, most likely, it's InDesign or a similar desktop publishing software used by publishing houses, may be it's mathematical pi or math & technical, etc. With all this number of Times clones available for use in LaTeX, it's a shame that a decent math font is not available yet in any of these clones. Even commercial ones like mtpro2 aren't as good as those used internally by big publishing companies. There are new attempts like stix2 but still not as good either.
– AboAmmarDec 24 '18 at 10:51
newtxmathmath font package was in use. There are many, many Times Roman clones out there. Anyway, do you have access to the pdf file? – Mico Dec 23 '18 at 19:59pdffonts <file>.pdfand you'll get a list of the used fonts. – Dec 23 '18 at 20:48mathematical piormath & technical, etc. With all this number of Times clones available for use in LaTeX, it's a shame that a decent math font is not available yet in any of these clones. Even commercial ones likemtpro2aren't as good as those used internally by big publishing companies. There are new attempts likestix2but still not as good either. – AboAmmar Dec 24 '18 at 10:51