Discovering Exotics at Jefferson Lab

The Hadron and Nuclear Physics group at the University of York is looking for a bright and enthusiastic PhD student to
discover exotic particles at Jefferson Laboratory utilizing intense electron beam and CLAS detector.
The fundamental theory thought to describe the strong interaction is Quantum Chromodynamics (QCD). QCD permits a large variety of bound states of quarks. The simplest and best-established configurations are mesons (quark-anti-quark systems) and baryons (3 quark systems). The field is currently undergoing rapid change with claims of tetraquarks, pentaquarks, hexaquarks and hadronic molecules only recently starting to reveal themselves. The advance has been made possible through exploiting cutting-edge particle beams at the frontiers of intensity, coupled for the first time with large acceptance particle detectors. The field has attracted very significant public interest and has high scientific impact. Stories about discoveries of new exotic particles attract significant media attention.
Our group is leading exciting studies which are revealing six-quark states - hexaquarks [PRL 1,2,3,4]. We exploit the uniquely clean and controlled production environment accessible through photo- and electro-induced reactions. Proving the exotic nature of a new particle is a challenging task for the majority of the cases. However hexaquarks, where baryon number B=2 are easily identifiable. Our group was involved in a recent discovery of a first non-trivial hexaquark, the d* (2380), having quark content uuuddd. A large fraction of our current activities are now devoted to this discovery: we have recently shown that the d*(2380) may form copiously within neutron stars influencing fundamental properties [PLB] and also be produced significantly in early Universe.
Like any other particles, the d*(2380) does not appear alone, but as a part of an SU(3) multiplet. In the d*'s case it is antidecuplet, so we expect 9 more particles with the same spin-parity (JP = 3+) but different strangeness to be discovered. The next candidate for the discovery would be ds - a particle with a quark content uuudds. This particle can be produced in large quantities at the JLab facility and detected by the high acceptance CLAS12 detector apparatus. After the energy and the luminosity upgrade of the JLab one can collect adequate statistics within few weeks of data taking. The first CLAS beam time with a deuteron target has been just started. For a PhD student it would be a golden opportunity to start the project with the data taking and complete it with an important discovery paper.