Possibility that Charmed Vector Mesons are Lighter than Charmed Pseudoscalars

Chiral symmetry breaking and meson-nucleon sigma commutators: A review

“…In addition, no significant enhancement of (A'~u,~X ) is found with respect to (&~&s~X). A strong enhancement comes about, as just mentioned above, if eo is coupled to the Goldstone boson of scale invariance: In this case one expects (Altarelli, Cabibbo, and Maiani, 1971a;Crewther, 1971;Mathur, 1971) estimates, it appears that this could be something more than just an accidental coincidence. Taking these enhancements literally, this could mean that further admixtures in the symmetry-breaking…”

“…two very similar calculations (Reya, 1972;Nasrallah and Schilcher, 1973) using fixed-t dispersion relations yielded positive values for o~~~~, in agreement with other estimates, a negative value for the kaon -nucleon o-term appears to be more than unlikely. Although, at the present stage, it is virtually impossible to state a reliable lower limit for o-~~~~, Table II (Altarelli, Cabibbo, and Maiani, 1971a;Crewther, 1971;Mathur, 1971) our "conventional" understanding of symmetry-breaking mechanisms, which we are going to discuss now.…”

“…Since np breaks SU(3) X SU(3) and n8 breaks SU(3) as well as SU(3) X SU(3), we cannot allow (Ã~uo~X} to be different by as much as an order of magnitude, say, from (1V~u8~X} and still have the two symmetries broken by a comparable amount. LThere could be a possible enhancement of (A~ND~LV} with respect to (iV~n8~A}, if 'one assumes (Altarelli, Cabibbo, and Maiani, 1971a;Crewther, 1971;Mathur, 1971) uo to be coupled to the Goldstone boson of a further symmetry, namely scale invariance. However, the main motivation for a strongly enhanced (lV~up~cV) appears to be obsolete by now, since, according to Table I and to what we have said in Sec.…”

Lifetimes and heavy quark expansion

“…The charm-quark decay as the dominant contribution to D-meson decays was considered, e.g., in 1974/5 by Gaillard, Lee and Rosner [77], by Kingsley, Treiman, Wilczek and Zee [78], by Ellis, Gaillard and Nanopoulos [79] and by Altarelli, Cabibbo and Maiani [80]. In [79] the total lifetime of the charm meson was calculated to be about 0.5 ps −1 , by taking only the LO-QCD value of c 3 with vanishing internal quark masses into account.…”

Antitriplet charmed baryon decays with SU(3) flavor symmetry

“…Since BESIII and LHCb are expected to search for all possible antitriplet charmed baryon decays, one can test whether or not the studies of Λ þ c → B n M can be applied to Ξ 0;þ c → B n M. Theoretically, the factorization for the b baryon decays [8][9][10][11][12][13] does not work for the charmed baryon decays, which receive corrections by taking into account the nonfactorizable effects [14][15][16][17][18][19]. On the other hand, the possible b or c hadron decay modes can be examined by the SUð3Þ f symmetry [20][21][22][23][24][25][26][27][28][29][30][31]. Furthermore, the symmetry approach has been extended to explore the doubly and triply charmed baryon decays [31], which helps to establish the spectroscopies of the doubly and triply charmed baryon states [32], such as the to-be-confirmed Ξ þ cc state [33][34][35][36][37][38].…”