Rare particle decay search narrows X(3872) mystery, constrains exotic matter models
Scientists found no evidence for a theorized decay pathway of the exotic X(3872) particle, setting strict limits on how often it decays this way. The negative result constrains competing theories about whether this particle is conventional matter or something entirely new—crucial for validating quantum models used across particle physics research.
Originaltitel: Search for <em>X</em>(3872) â Ï<sup>0</sup>Ï<sup>0</sup>Ï<sub><em>c</em>1,2</sub>
<p>Using 10.1 fb(-1) of e(+)e(-) collision data collected by the BESIII detector with center-of-mass energies between 4.15 GeV and 4.30 GeV, we search for the decays X(3872) -> pi(0)pi(0)chi(c1, 2), where the X(3872) is produced in e(+)e(-) -> gamma X(3872). No evidence above 3 sigma is found for either decay. Upper limits at the 90% CL on the branching fractions of X(3872) -> pi(0)pi(0)chi(c1, 2) normalized to the branching fraction of X(3872) -> pi(+)pi(-)J/psi are set to be BX(3872) -> pi(0)pi(0)chi(c1))/B(X(3872) -> pi(+)pi(-)J/psi < 1.1 and B(X(3872) -> pi(0)pi(0)chi(c2))/B(X(3872) -> pi(+)pi(-)J/psi < 0.5, taking into account both statistical and systematic uncertainties.</p>