Search

The China Dark Matter Experiment reports results on light WIMP dark matter searches at the China Jinping Underground Laboratory with a germanium detector array with a total mass of 20 g. The physics threshold achieved is 177 eVee ("ee" represents electron equivalent energy) at 50% signal efficiency. With 0.784 kg-days of data, exclusion region on spin-independent coupling with the nucleon is derived, improving over our earlier bounds at WIMP mass less than 4.6 GeV. [ABSTRACT FROM AUTHOR]

Stimulated by the recent LHCb observation of a new exotic charged structure T+cc, we propose to use the central diffractive mechanism existing in the γp→D+̅T-ccΛ+c (̅T-cc is the antiparticle of T+cc) reaction to produce T+cc. Our theoretical approach is based on the chiral unitary theory where the T+cc resonance is dynamically generated. With the coupling constant of the T+cc to DD* channel obtained from chiral unitary theory, the total cross sections of the γp→D+̅T-ccΛ+c reaction are evaluated. Our study indicates that the cross section for γp→D+̅T-ccΛ+c reaction is on the order of 1.0 pb, which is accessible at the proposed the Electron-Ion Collider in China [Front. Phys. (Beijing) 16, 64701 (2021)] or the U.S. [Eur. Phys. J. A 52, 268 (2016)] due to the higher luminosity. If measured and confirmed in the future experiments, the predicted total cross sections can be used to verify the (molecular) nature of the T+cc. [ABSTRACT FROM AUTHOR]

We investigate the possibility of studying the strange hidden-charm pentaquark state Pcs(4459) by photon-induced reactions on a proton target in an effective Lagrangian approach. The production process is described by the t-channel K-exchange, the u-channel Λ exchange, the contract term, and the s-channel nucleon pole. Our theoretical approach is based on the assumption that Pcs(4459) with JP=1/2- or JP=3/2- can be interpreted as a molecule composed of ¯D∗Ξc. Using the coupling constants of the PJPcs to γΛ and K-p channels obtained from molecule picture of the PJPcs(4459), the total cross-sections of the process γp→PJPcsK+ is evaluated. Our calculation indicates that the cross-section for γp→P1/2-csK+ and γp→P3/2-csK+ are of the order of 10.0 pb and 5.0 pb, respectively. In addition, we compute the cross section by assuming Pcs(4459) as a compact pentaquark and find it is quite different from the results of ̅D*Ξc molecule. Those results can be measured in future experiments, such as the Electron-Ion Collider in China and the United States, and can be used to test the nature of the Pcs. [ABSTRACT FROM AUTHOR]

In this work, we report on a theoretical study of possible pentaquark states Λb0(5912) and Λb0(5920) in the γp→Λb0(*)B+ reactions within an effective Lagrangian approach. In addition to the contributions from the s-channel nucleon pole and t-channel B*- exchange, the contact term contribution is also included. Our theoretical approach is based on the chiral unitary theory where the Λb0(5912) and Λb0(5920) resonances are dynamically generated. Within the coupling constants of the Λb0(5912) and Λb0(5920) to Bp and B*p channels obtained from chiral unitary theory, the total and differential cross sections of the γp→Λb0(*)B+ are evaluated. Our calculation indicates that the cross section for γp→Λb0(5912)B+ and γp→Λb0(5920)B+ reactions are of the order of 0.0164 and 0.00527 nb, respectively. If measured in future experiments, such as the Electron-Ion Collider in China or the United States, then the predicted total cross sections and specific features of the angular distributions can be used to test the (molecular) nature of the Λb0(5912) and Λb0(5920) that they may be pentaquark states. [ABSTRACT FROM AUTHOR]