BEGIN:VCALENDAR VERSION:2.0 METHOD:PUBLISH PRODID:-//Missouri State University/Calendar of Events//EN CALSCALE:GREGORIAN X-WR-TIMEZONE:America/Chicago BEGIN:VTIMEZONE TZID:America/Chicago BEGIN:DAYLIGHT TZOFFSETFROM:-0600 TZOFFSETTO:-0500 DTSTART:20070311T020000 RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU TZNAME:CDT END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:-0500 TZOFFSETTO:-0600 DTSTART:20071104T020000 RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU TZNAME:CST END:STANDARD END:VTIMEZONE BEGIN:VEVENT UID:c27e5e31-c1f4-4b29-babd-a3edad0c6926.217364@calendar.missouristate.edu CREATED:20210823T223316Z LAST-MODIFIED:20210823T223316Z LOCATION:Kemper Hall 206 SUMMARY:PAMS Seminar: "A Measurement of the 2S1/2-8D5/2 Transition in Hydr ogen" by Dr. Adam Brandt DESCRIPTION:Adam Brandt is an alumnus of PAMS\, graduating in 2014 with a BS in Physics. He recently finished his PhD studies at Colorado State Uni versity in atomic physics\, and now works at NIST in the Ion Storage grou p.\n\n\nAbstract:Over the past decade\, there has been renewed interest i n precision spectroscopy of atomic hydrogen and hydrogen-like species due to the so-called proton radius puzzle. The proton radius puzzle arose la rgely due to a measurement of the Lamb shift on muonic hydrogen\, a hydro gen atom where the electron is replaced a muon\, which resulted in a dete rmination of the proton radius that was in significant statistical disagr eement with the proton radius obtained from hydrogen spectroscopy at the time. We present a new measurement of the 2S1/2–8D5/2 transition with a c ryogenic hydrogen beam\, and the spectroscopy laser directly referenced t o a coherent optical frequency comb. The measured resonance frequency is ?=770649561570.8(2.0) kHz\, which corresponds to a relative uncertainty 2 .5×10-12. Combining our result with the most recent measurement of the 1S –2S transition\, we find a proton radius of rp=0.8581(50) fm and a Rydber g constant of R8=10973731.568330(52) m-1. Our result has a 3.4 s disagree ment with the proton radius obtained from the muonic hydrogen Lamb shift measurement and a combined 1.8 s disagreement with the 2014 hydrogenic wo rld average.\n\n\nThis seminar will be held in Kemper 206. X-ALT-DESC;FMTTYPE=text/html:<html><head><title></title></head><body><p><s trong>Adam Brandt&nbsp\;is an alumnus of PAMS\, graduating in 2014 with a BS in Physics. He recently finished his PhD studies at Colorado State Un iversity in atomic physics\, and&nbsp\;</strong><b>now works at NIST in t he Ion Storage group.</b></p>\n<p>Abstract:<br>Over the past decade\, the re has been renewed interest in precision spectroscopy of atomic hydrogen and hydrogen-like species due to the so-called proton radius puzzle. The proton radius puzzle arose largely due to a measurement of the Lamb shif t on muonic hydrogen\, a hydrogen atom where the electron is replaced a m uon\, which resulted in a determination of the proton radius that was in significant statistical disagreement with the proton radius obtained from hydrogen spectroscopy at the time. We present a new measurement of the 2 S1/2–8D5/2 transition with a cryogenic hydrogen beam\, and the spectrosco py laser directly referenced to a coherent optical frequency comb. The me asured resonance frequency is ?=770649561570.8(2.0) kHz\, which correspon ds to a relative uncertainty 2.5×10-12. Combining our result with the mos t recent measurement of the 1S–2S transition\, we find a proton radius of rp=0.8581(50) fm and a Rydberg constant of R8=10973731.568330(52) m-1. O ur result has a 3.4 s disagreement with the proton radius obtained from t he muonic hydrogen Lamb shift measurement and a combined 1.8 s disagreeme nt with the 2014 hydrogenic world average.</p>\n<p>This seminar will be h eld in Kemper 206.</p></body></html> DTSTART;TZID=America/Chicago:20210916T160000 DTEND;TZID=America/Chicago:20210916T170000 SEQUENCE:0 URL:https://physics.missouristate.edu/seminars.htm CATEGORIES:Public,Alumni,Current Students,Faculty,Future Students,Staff END:VEVENT END:VCALENDAR