<html><body><div style="font-family: arial,helvetica,sans-serif; font-size: 12pt; color: #000000"><div>There will be a seminar next Friday. It is of interest to PRad group. </div><div><br></div><div data-marker="__SIG_PRE__">-Eugene</div><div><br></div><hr id="zwchr" data-marker="__DIVIDER__"><div data-marker="__HEADERS__"><b>From: </b>"Stephanie Tysor" <stysor@jlab.org><br><b>To: </b>jlab-seminars@jlab.org<br><b>Cc: </b>"Janet Prater" <prater@jlab.org>, "Kim Kindrew" <kindrew@jlab.org><br><b>Sent: </b>Friday, January 6, 2017 11:04:24 AM<br><b>Subject: </b>[Jlab-seminars] Upcoming Physics Seminars: January 13, 2017 (Jan C. Bernauer), January 20, 2017 (Randolf Pohl)<br></div><div><br></div><div data-marker="__QUOTED_TEXT__"><p><br></p><div style="mso-element:para-border-div;border:none;border-bottom:solid
windowtext 1.5pt;
padding:0in 0in 1.0pt 0in" data-mce-style="mso-element: para-border-div; border: none; border-bottom: solid windowtext 1.5pt; padding: 0in 0in 1.0pt 0in;"><p class="MsoNormal" style="text-align:center;border:none;
mso-border-bottom-alt:solid windowtext
1.5pt;padding:0in;mso-padding-alt:0in 0in 1.0pt 0in" align="center" data-mce-style="text-align: center; border: none; mso-border-bottom-alt: solid windowtext 1.5pt; padding: 0in; mso-padding-alt: 0in 0in 1.0pt 0in;"><b style="mso-bidi-font-weight:normal" data-mce-style="mso-bidi-font-weight: normal;"><span style="font-size:48.0pt;line-height:
115%;font-family:"Times New Roman",serif" data-mce-style="font-size: 48.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">Physics Seminar</span></b></p></div><p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:
0in;margin-bottom:.0001pt;text-align:center;line-height:normal" align="center" data-mce-style="mso-margin-top-alt: auto; margin-bottom: .0001pt; text-align: center; line-height: normal;"><b style="mso-bidi-font-weight:normal" data-mce-style="mso-bidi-font-weight: normal;"><span style="font-size:20.0pt;font-family:
"Times New
Roman",serif;mso-fareast-font-family:"Times New
Roman"" data-mce-style="font-size: 20.0pt; font-family: 'Times New Roman',serif; mso-fareast-font-family: 'Times New Roman';">Jan C. Bernauer</span></b></p><p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:
0in;margin-bottom:.0001pt;text-align:center;line-height:normal" align="center" data-mce-style="mso-margin-top-alt: auto; margin-bottom: .0001pt; text-align: center; line-height: normal;"><b style="mso-bidi-font-weight:normal" data-mce-style="mso-bidi-font-weight: normal;"><span style="font-size:20.0pt;font-family:
"Times New
Roman",serif;mso-fareast-font-family:"Times New
Roman"" data-mce-style="font-size: 20.0pt; font-family: 'Times New Roman',serif; mso-fareast-font-family: 'Times New Roman';">Massachusetts Institute of Technology</span></b></p><p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:
0in;margin-bottom:.0001pt;text-align:center;line-height:normal" align="center" data-mce-style="mso-margin-top-alt: auto; margin-bottom: .0001pt; text-align: center; line-height: normal;"><b style="mso-bidi-font-weight:normal" data-mce-style="mso-bidi-font-weight: normal;"><span style="font-size:20.0pt;font-family:
"Times New
Roman",serif;mso-fareast-font-family:"Times New
Roman"" data-mce-style="font-size: 20.0pt; font-family: 'Times New Roman',serif; mso-fareast-font-family: 'Times New Roman';"> </span></b></p><p class="MsoNormal" style="text-align:center" align="center" data-mce-style="text-align: center;"><i style="mso-bidi-font-style:
normal" data-mce-style="mso-bidi-font-style: normal;"><span style="font-size:20.0pt;line-height:115%;font-family:"Times
New Roman",serif;
mso-fareast-font-family:"Times New Roman"" data-mce-style="font-size: 20.0pt; line-height: 115%; font-family: 'Times New Roman',serif; mso-fareast-font-family: 'Times New Roman';">Two-photon Exchange in Proton Elastic Scattering</span></i></p><p class="MsoNormal" style="text-align:center" align="center" data-mce-style="text-align: center;"><span style="font-size:16.0pt;line-height:115%;font-family:"Times New
Roman",serif" data-mce-style="font-size: 16.0pt; line-height: 115%; font-family: 'Times New Roman',serif;"><br> </span><span style="font-size:18.0pt;line-height:115%;font-family:"Times
New Roman",serif" data-mce-style="font-size: 18.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">Abstract:</span></p><p class="MsoNormal" style="text-align:center" align="center" data-mce-style="text-align: center;"><br> <i style="mso-bidi-font-style:normal" data-mce-style="mso-bidi-font-style: normal;"><span style="font-size:14.0pt;line-height:
115%;font-family:"Times New Roman",serif" data-mce-style="font-size: 14.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">Recent interest in the proton electromagnetic form factors is partly motivated by the discrepancy found in the determination of the electric-to-magnetic form factor ratio using different techniques. Results from scattering experiments using the Rosenbluth technique indicate that the form factor ratio is constant as a function of $Q^2$ while experiments employing polarization show a clear, roughly linear, decline of the ratio. A possible explanation is the typically unaccounted for contribution of hard two-photon exchange to the scattering process. Theoretical calculations show large variations, many indicating an effect of the right sign and magnitude. Direct verification was sought by experiments at VEPP-3, Jefferson Lab and by the OLYMPUS collaboration at DESY. In the talk, I will discuss the<br> OLYMPUS experiment and results and summarize our current understanding of TPE and the proton form factors in the context of the three experiments.</span></i></p><p class="MsoNormal" style="text-align:center" align="center" data-mce-style="text-align: center;"><i style="mso-bidi-font-style:
normal" data-mce-style="mso-bidi-font-style: normal;"><span style="font-size:14.0pt;line-height:115%;font-family:"Times
New Roman",serif" data-mce-style="font-size: 14.0pt; line-height: 115%; font-family: 'Times New Roman',serif;"> </span></i></p><p class="MsoNormal" style="text-align:center" align="center" data-mce-style="text-align: center;"><b style="mso-bidi-font-weight:
normal" data-mce-style="mso-bidi-font-weight: normal;"><span style="font-size:14.0pt;line-height:115%;font-family:"Times
New Roman",serif" data-mce-style="font-size: 14.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">Friday, January 13, 2017</span></b></p><p class="MsoNormal" style="text-align:center" align="center" data-mce-style="text-align: center;"><b style="mso-bidi-font-weight:
normal" data-mce-style="mso-bidi-font-weight: normal;"><span style="font-size:14.0pt;line-height:115%;font-family:"Times
New Roman",serif" data-mce-style="font-size: 14.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">11:00 am</span></b></p><p class="MsoNormal" style="text-align:center" align="center" data-mce-style="text-align: center;"><b style="mso-bidi-font-weight:
normal" data-mce-style="mso-bidi-font-weight: normal;"><span style="font-size:14.0pt;line-height:115%;font-family:"Times
New Roman",serif" data-mce-style="font-size: 14.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">CEBAF Auditorium</span></b></p><p class="MsoNormal" style="text-align:center" align="center" data-mce-style="text-align: center;"><b style="mso-bidi-font-weight:
normal" data-mce-style="mso-bidi-font-weight: normal;"><span style="font-size:14.0pt;line-height:115%;font-family:"Times
New Roman",serif" data-mce-style="font-size: 14.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">_________________________________________________________________________________</span></b></p><p class="MsoNormal" style="text-align:center" align="center" data-mce-style="text-align: center;"><br></p><div style="mso-element:para-border-div;border:none;border-bottom:solid
windowtext 1.5pt;
padding:0in 0in 1.0pt 0in" data-mce-style="mso-element: para-border-div; border: none; border-bottom: solid windowtext 1.5pt; padding: 0in 0in 1.0pt 0in;"><p class="MsoNormal" style="text-align:center;border:none;
mso-border-bottom-alt:solid windowtext
1.5pt;padding:0in;mso-padding-alt:0in 0in 1.0pt 0in" align="center" data-mce-style="text-align: center; border: none; mso-border-bottom-alt: solid windowtext 1.5pt; padding: 0in; mso-padding-alt: 0in 0in 1.0pt 0in;"><b style="mso-bidi-font-weight:normal" data-mce-style="mso-bidi-font-weight: normal;"><span style="font-size:28.0pt;line-height:
115%;font-family:"Times New Roman",serif" data-mce-style="font-size: 28.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">Physics Seminar</span></b></p></div><p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:
0in;margin-bottom:.0001pt;text-align:center;line-height:normal" align="center" data-mce-style="mso-margin-top-alt: auto; margin-bottom: .0001pt; text-align: center; line-height: normal;"><b style="mso-bidi-font-weight:normal" data-mce-style="mso-bidi-font-weight: normal;"><span style="font-size:16.0pt;font-family:
"Times New
Roman",serif;mso-fareast-font-family:"Times New
Roman"" data-mce-style="font-size: 16.0pt; font-family: 'Times New Roman',serif; mso-fareast-font-family: 'Times New Roman';">Randolf Pohl</span></b></p><p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:
0in;margin-bottom:.0001pt;text-align:center;line-height:normal" align="center" data-mce-style="mso-margin-top-alt: auto; margin-bottom: .0001pt; text-align: center; line-height: normal;"><b style="mso-bidi-font-weight:normal" data-mce-style="mso-bidi-font-weight: normal;"><span style="font-size:16.0pt;font-family:
"Times New
Roman",serif;mso-fareast-font-family:"Times New
Roman"" data-mce-style="font-size: 16.0pt; font-family: 'Times New Roman',serif; mso-fareast-font-family: 'Times New Roman';">Johannes Gutenberg-University, Mainz Germany</span></b></p><p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:
0in;margin-bottom:.0001pt;text-align:center;line-height:normal" align="center" data-mce-style="mso-margin-top-alt: auto; margin-bottom: .0001pt; text-align: center; line-height: normal;"><b style="mso-bidi-font-weight:normal" data-mce-style="mso-bidi-font-weight: normal;"><span style="font-size:16.0pt;font-family:
"Times New
Roman",serif;mso-fareast-font-family:"Times New
Roman"" data-mce-style="font-size: 16.0pt; font-family: 'Times New Roman',serif; mso-fareast-font-family: 'Times New Roman';">Max-Planck Institute of Quantum Optics, Garching Germany</span></b></p><p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:
0in;margin-bottom:.0001pt;text-align:center;line-height:normal" align="center" data-mce-style="mso-margin-top-alt: auto; margin-bottom: .0001pt; text-align: center; line-height: normal;"><b style="mso-bidi-font-weight:normal" data-mce-style="mso-bidi-font-weight: normal;"><span style="font-size:16.0pt;font-family:
"Times New
Roman",serif;mso-fareast-font-family:"Times New
Roman"" data-mce-style="font-size: 16.0pt; font-family: 'Times New Roman',serif; mso-fareast-font-family: 'Times New Roman';"> </span></b></p><p class="MsoNormal" style="text-align:center" align="center" data-mce-style="text-align: center;"><i style="mso-bidi-font-style:
normal" data-mce-style="mso-bidi-font-style: normal;"><span style="font-size:14.0pt;line-height:115%;font-family:"Times
New Roman",serif;
mso-fareast-font-family:"Times New Roman"" data-mce-style="font-size: 14.0pt; line-height: 115%; font-family: 'Times New Roman',serif; mso-fareast-font-family: 'Times New Roman';">Shrinking the Proton –Laser Spectroscopy for Nuclear Physics and Fundamental Constants</span></i><span style="font-size:16.0pt;line-height:115%;font-family:"Times New
Roman",serif" data-mce-style="font-size: 16.0pt; line-height: 115%; font-family: 'Times New Roman',serif;"><br> Abstract:</span><span style="font-family:"Times New
Roman",serif" data-mce-style="font-family: 'Times New Roman',serif;"><br> <br> <i style="mso-bidi-font-style:normal" data-mce-style="mso-bidi-font-style: normal;">For more than a decade, the rms charge radius of the proton was known to be<br> 0.88fm, with about 1% uncertainty [1]. Two methods, elastic electron scattering<br> and precision laser spectroscopy of atomic hydrogen, yielded consistent values.<br> <br> In 2010, our result from laser spectroscopy of the exotic "muonic hydrogen" atom<br> yielded a 4% smaller value, 0.84 fm, with an uncertainty of less than 0.1%<br> [2,3]. In muonic hydrogen, a negative muon orbits a proton with a 200 times<br> smaller Bohr orbit than in regular hydrogen, which increases the sensitivity of<br> muonic hydrogen to the proton charge radius by 200^3 ~ 10 million!<br> Since 2010, the discrepancy increased to more than 7 sigmas [4], making it one<br> of the biggest discrepancies in the Standard Model.<br> <br> I will discuss the so-called "proton radius puzzle" [5], report on more<br> measurements in muonic atoms [6], and the result of a new measurement in regular<br> atomic hydrogen.</i><br> <br> </span><span style="font-size:9.0pt;line-height:115%;font-family:"Times
New Roman",serif" data-mce-style="font-size: 9.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">[1] P.J. Mohr et al. (CODATA 2006), Rev. Mod. Phys. </span><a href="callto:80,%20633%20%282008" target="_blank" data-mce-href="callto:80,%20633%20%282008"><span style="font-size:9.0pt;line-height:
115%;font-family:"Times New Roman",serif" data-mce-style="font-size: 9.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">80, 633 (2008</span></a><span style="font-size:9.0pt;line-height:115%;font-family:"Times
New Roman",serif" data-mce-style="font-size: 9.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">)<br> [2] Pohl et al. (CREMA coll.), Nature </span><a href="callto:466,%20213%20%282010" target="_blank" data-mce-href="callto:466,%20213%20%282010"><span style="font-size:9.0pt;line-height:
115%;font-family:"Times New Roman",serif" data-mce-style="font-size: 9.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">466, 213 (2010</span></a><span style="font-size:9.0pt;line-height:115%;font-family:"Times
New Roman",serif" data-mce-style="font-size: 9.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">)<br> [3] Antognini et al.,(CREMA coll.), Science </span><a href="callto:339,%20417%20%282013" target="_blank" data-mce-href="callto:339,%20417%20%282013"><span style="font-size:9.0pt;line-height:
115%;font-family:"Times New Roman",serif" data-mce-style="font-size: 9.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">339, 417 (2013</span></a><span style="font-size:9.0pt;line-height:115%;font-family:"Times
New Roman",serif" data-mce-style="font-size: 9.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">)<br> [4] Olive et al. (PDG 2014), Chin. Phys. C40, </span><a href="callto:090001%20%282014" target="_blank" data-mce-href="callto:090001%20%282014"><span style="font-size:9.0pt;line-height:115%;
font-family:"Times New Roman",serif" data-mce-style="font-size: 9.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">090001 (2014</span></a><span style="font-size:9.0pt;line-height:115%;font-family:"Times New
Roman",serif" data-mce-style="font-size: 9.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">)<br> [5] Pohl et al., Annu. Rev. Nucl. Part. Sci </span><a href="callto:63,%20175%20%282013" target="_blank" data-mce-href="callto:63,%20175%20%282013"><span style="font-size:9.0pt;line-height:
115%;font-family:"Times New Roman",serif" data-mce-style="font-size: 9.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">63, 175 (2013</span></a><span style="font-size:9.0pt;line-height:115%;font-family:"Times
New Roman",serif" data-mce-style="font-size: 9.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">)<br> [6] Pohl et al. (CREMA coll.), Science </span><a href="callto:353,%20669%20%282016" target="_blank" data-mce-href="callto:353,%20669%20%282016"><span style="font-size:9.0pt;line-height:
115%;font-family:"Times New Roman",serif" data-mce-style="font-size: 9.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">353, 669 (2016</span></a><span style="font-size:9.0pt;line-height:115%;font-family:"Times
New Roman",serif" data-mce-style="font-size: 9.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">)</span><i style="mso-bidi-font-style:normal" data-mce-style="mso-bidi-font-style: normal;"><span style="font-size:14.0pt;line-height:
115%;font-family:"Times New
Roman",serif;mso-fareast-font-family:"Times New
Roman"" data-mce-style="font-size: 14.0pt; line-height: 115%; font-family: 'Times New Roman',serif; mso-fareast-font-family: 'Times New Roman';"></span></i></p><p class="MsoNormal" style="text-align:center" align="center" data-mce-style="text-align: center;"><span style="font-family:"Times New Roman",serif" data-mce-style="font-family: 'Times New Roman',serif;"> </span></p><p class="MsoNormal" style="text-align:center" align="center" data-mce-style="text-align: center;"><b style="mso-bidi-font-weight:
normal" data-mce-style="mso-bidi-font-weight: normal;"><span style="font-size:12.0pt;line-height:115%;font-family:"Times
New Roman",serif" data-mce-style="font-size: 12.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">Friday, January 20, 2017</span></b></p><p class="MsoNormal" style="text-align:center" align="center" data-mce-style="text-align: center;"><b style="mso-bidi-font-weight:
normal" data-mce-style="mso-bidi-font-weight: normal;"><span style="font-size:12.0pt;line-height:115%;font-family:"Times
New Roman",serif" data-mce-style="font-size: 12.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">11:00 am</span></b></p><p class="MsoNormal" style="text-align:center" align="center" data-mce-style="text-align: center;"><b style="mso-bidi-font-weight:
normal" data-mce-style="mso-bidi-font-weight: normal;"><span style="font-size:12.0pt;line-height:115%;font-family:"Times
New Roman",serif" data-mce-style="font-size: 12.0pt; line-height: 115%; font-family: 'Times New Roman',serif;">CEBAF Auditorium<i style="mso-bidi-font-style:normal" data-mce-style="mso-bidi-font-style: normal;"></i></span></b></p><p><br></p><br>_______________________________________________<br>Jlab-seminars mailing list<br>Jlab-seminars@jlab.org<br>https://mailman.jlab.org/mailman/listinfo/jlab-seminars<br></div></div></body></html>