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<div style=""><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Dear all,</span></div>
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<div style=""><font color="#000000" face="Calibri, Arial, Helvetica, sans-serif">find below a reminder for the theory seminar tomorrow.</font></div>
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<div style=""><font color="#000000" face="Calibri, Arial, Helvetica, sans-serif">Best regards,</font></div>
<div style=""><font color="#000000" face="Calibri, Arial, Helvetica, sans-serif">Carlota, Raza, Miguel</font></div>
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<div style=""><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Theory Seminar: Monday, May 20, 1:00 – 2:00pm, Room L102</span></div>
<div style=""><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Henry Lamm</span><span><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> </span></span><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">(University
of Maryland)</span></div>
<div style=""><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Title:</span><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> </span><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Model-independent
bounds on semi-leptonic decays $B_c^+$</span></div>
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<div style=""><font color="#222222" face="Arial, Helvetica, sans-serif" size="4"><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Abstract:</span></font><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> </span><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Model-independent
bounds on $R(J/\psi) \! \equiv \!\mathcal{BR} (B_c^+ \rightarrow J/\psi \, \tau^+\nu_\tau)/\mathcal{BR} (B_c^+ \rightarrow J/\psi \, \mu^+\nu_\mu)$ are obtained through a combination of dispersive relations, heavy-quark relations at zero-recoil, and the limited
existing form factor determinations from lattice QCD\@. The resulting 95\% confidence-level bound, $0.20\leq R(J/\psi)\leq0.39$, agrees with the recent LHCb result at $1.3 \, \sigma$, and removes the dominant model-dependent uncertainty from theory predictions.
Using the same techniques, a prediction of $R(\eta_c)=0.29(5)$ is obtained.</span><br>
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