Lepton Asymmetries in FCNC Decays of Λb

Lepton polarization asymmetries for FCNC decays of the $Λ_b$ baryon

Branching ratios, lepton forward-backward asymmetries, and lepton polarization asymmetries for the flavor-changing neutral current (FCNC) dileptonic decays of the $Λ_b$ baryon to the ground state and a number of excited state $Λ$ baryons are calculated using form factors extracted using wave functions from a constituent quark model. The SM branching ratios for the transition to the ground state calculated using these quark model form factors are consistent with the recent measurement reported by the LHCb collaboration. It is shown that the lepton polarization asymmetries are largely insensitiv…

Lepton FCNC in Type III Seesaw Model

In Type III seesaw model, there are tree level flavor changing neutral currents (FCNC) in the lepton sector, due to mixing of charged particles in the leptonic triplet introduced to realize seesaw mechanism, with the usual charged leptons. In this work we study these FCNC effects in a systematic way using available experimental data. Several FCNC processes have been studied before. The new processes considered in this work include: lepton flavor violating processes $τ\to P l$, $τ\to V l$, $V \to l \bar l'$, $P \to l \bar l'$, $M\to M' l \bar l'$ and muonium-antimuonium oscillation. Results obt…

Charge and spin asymmetries in elastic lepton-nucleon scattering

Elastic lepton scattering off of a nucleon has proved to be an efficient tool to study the structure of the hadron. Modern cross section and asymmetry measurements at Jefferson Lab require effects beyond the leading order Born approximation to be taken into account. Availability of unpolarized beams of both electrons and positrons in respective experiments would enable to reduce systematic uncertainties due to higher-order charge-odd contributions. In addition, information on an unpolarized electron-to-positron cross section ratio could serve as a test for theoretical models that provide predi…

介子凝聚与轻子味不对称性在宇宙学引力波背景中的特征

Signatures from pion condensation and lepton flavor asymmetries in the cosmological gravitational wave background

研究大QCD时期轻子味不对称性如何引发介子凝聚，并探讨其对低频引力波谱的特征影响，通过比较引力波信号与标准情况下的轻子不对称性提供新约束。