1763711
Electromagnetic radiation of baryons containing two heavy quarks
The two heavy quarks in a baryon which contains two heavy quarks and a light one can constitute a scalar or axial vector diquark. We study the electromagnetic radiation of such baryons: (i) ${\ensuremath{\Xi}}_{{(\mathrm{bc})}_{1}}\ensuremath{\rightarrow}{\ensuremath{\Xi}}_{{(\mathrm{bc})}_{0}}+\ensuremath{\gamma},$ (ii) ${\ensuremath{\Xi}}_{{(\mathrm{bc})}_{1}}^{*}\ensuremath{\rightarrow}{\ensuremath{\Xi}}_{{(\mathrm{bc})}_{0}}+\ensuremath{\gamma},$ (iii) ${\ensuremath{\Xi}}_{{(\mathrm{bc})}_{0}}^{**}(1/2,l=1)\ensuremath{\rightarrow}{\ensuremath{\Xi}}_{{(\mathrm{bc})}_{0}}+\ensuremath{\gamma},$ (iv) ${\ensuremath{\Xi}}_{{(\mathrm{bc})}_{0}}^{**}(3/2,l=1)\ensuremath{\rightarrow}{\ensuremath{\Xi}}_{{(\mathrm{bc})}_{0}}+\ensuremath{\gamma},$ and (v) ${\ensuremath{\Xi}}_{{(\mathrm{bc})}_{0}}^{**}(3/2,l=2)\ensuremath{\rightarrow}{\ensuremath{\Xi}}_{{(\mathrm{bc})}_{0}}+\ensuremath{\gamma},$ where ${\ensuremath{\Xi}}_{{(\mathrm{bc})}_{0(1)}},{\ensuremath{\Xi}}_{{(\mathrm{bc})}_{1}}^{*}$ are S-wave bound states of a heavy scalar or axial vector diquark and a light quark, and ${\ensuremath{\Xi}}_{{(\mathrm{bc})}_{0}}^{**}(lg~1)$ are P- or D-wave bound states of a heavy scalar diquark and a light quark. The analysis indicates that these processes can be attributed to two categories and the physical mechanisms which are responsible for them are completely distinct. Measurements can provide good judgment for the diquark structure and a better understanding of the physical picture.
119299313
CP violation in $B^{\pm} \rightarrow \pi^{\pm}\pi^{+}\pi^{-}$ in the region with low invariant mass of one $\pi^{+}\pi^{-}$ pair
Recently, the large CP asymmetries in B → πππ decays were found by the LHCb Collaboration to localize in the region m π+π− < 0.4 GeV. We find such large localized CP asymmetries may be due to the interference between a light scalar and ρ(770) intermediate resonances. Consequently, we argue that the distribution of CP asymmetries in the Dalitz plots of three-body B decays could be very helpful for identifying the presence of the scalar resonance.
120908811
Mass spectra of doubly heavy mesons in Regge phenomenology
In Regge phenomenology, we first study the spectra of charmonium and bottomonium in the (n, M-2) plane and predict masses of some charmonium and bottomonium states which have not been observed now. Then, with the aid of the additivity of intercepts and inverse slopes, we calculate the masses of ground S-wave and P-wave c (b) over bar meson states and their first radial excited states. The predictions are in reasonable agreement with the existing experimental data and those suggested in many other approaches. The predictions may be useful for the discovery of the unobserved c (c) over bar, b (b) over bar, c (b) over bar mesons and the J(P) assignment of these states.
13937852
Strong decays of heavy baryons in the Bethe-Salpeter formalism
In this paper we study the properties of diquarks (composed of u and/or d quarks) in the Bethe-Salpeter (BS) formalism under the covariant instantaneous approximation. We calculate their BS wave functions and study their effective interaction with the pion. Using the effective coupling constant among the diquarks and the pion, in the heavy quark limit m{sub Q}{yields}{infinity}, we calculate the decay widths of {sigma}{sub Q}{sup (*)} (Q=c, b) in the BS formalism under the covariant instantaneous approximation and then give predictions of the decay widths {gamma}({sigma}{sub b}{sup (*)}{yields}{lambda}{sub b}+{pi})
15163914
Supernova Neutrinos Detection On Earth
In this paper, we first discuss the detection of supernova neutrino on Earth. Then we propose a possible method to acquire information about θ13 smaller than 1.5 ◦ by detecting the ratio of the event numbers of different flavor supernova neutrinos. Such an sensitivity cannot yet be achieved by the Daya Bay reactor neutrino experiment.
117975255
QCD factorization for $\Lambda_b^0\to\Lambda_c^+\pi^-$
We prove that in the limit $m_b, m_c\to\infty$ with $m_c/m_b$ fixed, factorization holds at order $\alpha_s$ for the decay $\Lambda_b^0\to\Lambda_c^+\pi^-$. This proof is done in the infinite-momentum frame in which the momenta of $\pi$, $\Lambda_c$, and $\Lambda_b$ go to infinity. Our result is renormalization scale and scheme independent at $\mathcal{O}(\alpha_s)$. This is the same as QCD factorization for $B \to D \pi$.
17743185
Nuclear dependence in transverse momentum distribution for Drell-Yan pair
Abstract In terms of multiple scattering picture, I compute the nuclear dependence in Drell-Yan transverse momentum distribution, dσ / dQ 2 dq T 2 , in hadron-nucleus collisions. I present the results for large q T region and discuss the possible suppression in small q T region.
7040957
Coherent multiple scattering effect in DIS
We present a QCD calculation of the coherent multiple scattering effect on single hadron production in semi-inclusive lepton-nucleus deep inelastic scattering (DIS). We show that the destructive interference of coherent multiple scattering leads to suppression in hadron productions. The suppression is similar to the expectations of energy loss calculations. We compare our calculation with experimental data.
14098391
Probing quark-gluon correlation functions
We review the applicability of the QCD factorization theorem to multiple scattering in deeply inelastic lepton-nucleus scattering. We show why an A{sup 1/3}-type nuclear enhancement can be calculated consistently in perturbative QCD. We derive the transverse momentum broadening of the leading pions in deeply inelastic lepton-nucleus collisions. We argue that the measurement of such transverse momentum broadening can provide direct information on the multiple-parton correlation functions inside a nucleus. We also estimate the numerical values of the broadening at different values of x{sub B} and Q{sup 2}. (c) 2000 The American Physical Society.
19032960
Transverse momentum broadening due to the multiple scattering
Using the Drell-Yan process in hadron-nucleus collisions and deeply inelastic lepton-nucleus scattering (DIS) as examples, I show that the transverse momentum broadening can be expressed in terms of four-parton correlation functions. I argue that jet broadening in DIS provide an excellent measurement of the four-parton correlation functions and a test of QCD treatment of the multiple scattering.
12485364
Jet broadening in deeply inelastic scattering
In deeply inelastic lepton-nucleus scattering (DIS), the average jet transverse momentum is broadened because of the multiple scattering in the nuclear medium. The size of jet broadening is proportional to the multi-parton correlation functions inside nuclei. We show that at leading order, jet broadening in DIS and nulcear enhancement in di-jet momentum imbalance and Drell-Yan $ $ share the same four-parton correlation functions. We argue that jet broadening in DIS provide an indenpendent measurement of the four-parton correlation functions and a test of QCD treatment of multiple scattering.