Investigation of the level spectra of nuclei in the northeast region of doubly magic^(40)Ca with intruder orbit g_(9/2)

This study utilizes large-scale shell model calculations with the extended pairing and multipole–multipole force model(EPQQM)to investigate low-lying states in the nuclei of^(42)Ca,^(42)Sc,and^(42−44)Ti.The model space in this study includes the fp shell as well as the intruder g_(9/2)orbit,which accurately reproduces the positive parity levels observed in the aforementioned nuclei and predicts high energy states with negative parity coupled with the intruder g_(9/2).The study further predicts two different configurations in^(43)Ti at around 6 MeV,specificallyπf_(7/2)^(2)νg_(9/2)andπf_(7/2)g_(9/2)νf_(7/2),both of which involve the intruder orbit g_(9/2).The levels coupled with the intruder g_(9/2)in^(44)Ti are predicted to lie between 7 and 11 MeV.The inclusion of the intruder orbit g_(9/2)is crucial for the exploration of high energy states in the northeast region of the doubly magic nucleus^(40)Ca.

Search for single production of vectorlike B-quarks at the LHC

New vectorlike quarks have been proposed in many scenarios of new physics beyond the Standard Model,which address the hierarchy problem and may be potentially discovered at the Large Hadron Collider(LHC).Based on a model-independent framework,we propose to search for the vectorlike B-quark(VLQ-B)and focus on resonant production via b-gluon fusion through chromomagnetic interactions.We then explore the possible signals of the VLQ-B through the B→tW decay mode at the 14 TeV LHC.After a rapid simulation of signal and background events,the 2σ excluded regions and the 5σdiscovery reach in the parameter plane of k_(B)-M_(B)are obtained at the LHC with an integrated luminosity of 300(3000)fb^(-1)in the dilepton final states.