1995/11/14 by Naoyuki Haba, Haba, Naoyuki, Chuichiro Hattori +7
Computer Science · Physics and Astronomy · #Computational Physics and Python Applications #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Particle physics theoretical and experimental studies #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/9511312
arxiv created 1995/11/14 · openalex publication_date 1995/11/14 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In the context of the Calabi-Yau string model we discuss the origin of characteristic pattern of quark-lepton masses and the CKM matrix. The discrete R-symmetry Z2k+1 × Z2 is introduced and the Z2 is assigned to the R-parity. The gauge symmetry at the string scale is broken into the standard model gauge group at an intermediate energy scale. At energies below the intermediate scale down-type quarks and also leptons are mixed with unobserved heavy states, respectively. On the other hand, there are no such mixings for up-type quarks. The large mixings between light states and heavy ones cause different mass pattern of leptons and down-type quarks from that of up-type quarks and yield a nontrivial CKM matrix for quarks but a trivial one for leptons. The mixing mechanism is illustrated using a two-generation toy model.