Search results for "baryon number"
showing 10 items of 28 documents
The baryon number two system in the Chiral Soliton Model
2012
We study the interaction between two B = 1 states in a chiral soliton model where baryons are described as non-topological solitons. By using the hedgehog solution for the B = 1 states we construct three possible B = 2 configurations to analyze the role of the relative orientation of the hedgehog quills in the dynamics. The strong dependence of the intersoliton interaction on these relative orientations reveals that studies of dense hadronic matter using this model should take into account their implications.
Longitudinal dynamics of multiple conserved charges
2021
Abstract It is the goal of the RHIC BES program and the future FAIR and NICA facilities to produce compressed baryonic matter. In experiments such as these, strong gradients in baryon density are expected, and therefore the diffusion of baryon number could play a major role in the description of the fireball. The constituents of the produced matter carry a multitude of conserved charges, namely the baryon number, strangeness and electric charge, so that the diffusion currents of conserved charge couple with each other. Therefore, baryon density gradients in the above-mentioned high-density collision experiments will generate equalizing currents in all conserved charges. In common fluid dyna…
Nuclear Parton Distributions - a DGLAP Analysis
1999
Nuclear parton distributions $f_A(x,Q^2)$ are studied within a framework of the DGLAP evolution. Measurements of $F_2^A/F_2^D$ in deep inelastic $lA$ collisions, and Drell--Yan dilepton cross sections measured in $pA$ collisions are used as constraints. Also conservation of momentum and baryon number is required. It is shown that the calculated $Q^2$ evolution of $F_2^{\rm Sn}/F_2^{\rm C}$ agrees very well with the recent NMC data, and that the ratios $R_f^A=f_A/f$ are only moderately sensitive to the choice of a specific modern set of free parton distributions. For general use, we offer a numerical parametrization of $R_f^A(x,Q^2)$ for all parton flavours $f$ in $A>2$, and at $10^{-6}\l…
Topological structure of dense hadronic matter
2007
8 pages, 4 figures.-- ISI Article Identifier: 000244425500052.
Searches for the baryon- and lepton-number violating decaysB0→Λc+l−,B−→Λl−, andB−→Λ¯l−
2011
Searches for $B$ mesons decaying to final states containing a baryon and a lepton are performed, where the baryon is either $\Lambda_c$ or $\Lambda$ and the lepton is a muon or an electron. These decays violate both baryon and lepton number and would be a signature of physics beyond the standard model. No significant signal is observed in any of the decay modes, and upper limits in the range $(3.2-520) \times 10^{-8}$ are set on the branching fractions at the 90% confidence level.
Dependence of hadron spectra on decoupling temperature and resonance contributions
2003
Using equilibrium hydrodynamics with initial conditions for the energy and net baryon number densities from the perturbative QCD + saturation model, a good simultaneous description of the measured pion, kaon and (anti)proton spectra in central Au+Au collisions at $\sqrt s=130 A$GeV is found with a single decoupling temperature $\Tdec=150...160$ MeV. The interplay between the resonance content of the EoS and the development of the transverse flow leads to inverse slopes and $$ of hadrons which increase with decreasing $\Tdec$. The origin of this result is discussed.
Unified Approach to Dense Matter
2004
We apply the Skyrme model to dense hadronic matter, which provides a unified approach to high density, valid in the large Nc limit. In our picture, dense hadronic matter is described by the classical soliton configuration with minimum energy for the given baryon number density. By incorporating the meson fluctuations on such ground state we obtain an effective Lagrangian for meson dynamics in a dense medium. Our starting point has been the Skyrme model defined in terms of pions, thereafter we have extended and improved the model by incorporating other degrees of freedom such as dilaton, kaons and vector mesons.
Numerical study of leptogenesis in a 5D split fermion model with bulk neutrinos
2010
We study numerically a 5D hybrid model which incorporates a split fermion scenario and bulk neutrinos. We perform a Monte Carlo analysis of the model in order to find the regions in the parameter space allowing for realization of the leptogenesis. We find that higher order Yukawa terms must be included in order the model to produce a CP violation and net baryon number sufficient for the creation of the observed baryon asymmetry of the Universe.
Neutrino Masses, Grand Unification, and Baryon Number Violation
2014
If grand unification is real, searches for baryon-number violation should be included on the list of observables that may reveal information regarding the origin of neutrino masses. Making use of an effective-operator approach and assuming that nature is SU(5) invariant at very short distances, we estimate the consequences of different scenarios that lead to light Majorana neutrinos for low-energy phenomena that violate baryon number minus lepton number (B-L) by two (or more) units, including neutron-antineutron oscillations and B-L violating nucleon decays. We find that, among all possible effective theories of lepton-number violation that lead to nonzero neutrino masses, only a subset is,…
A full picture of large lepton number asymmetries of the Universe
2017
A large lepton number asymmetry of (0.1−1) at present Universe might not only be allowed but also necessary for consistency among cosmological data. We show that, if a sizeable lepton number asymmetry were produced before the electroweak phase transition, the requirement for not producing too much baryon number asymmetry through sphalerons processes, forces the high scale lepton number asymmetry to be larger than about 03. Therefore a mild entropy release causing (10-100) suppression of pre-existing particle density should take place, when the background temperature of the Universe is around T = (10−2-102) GeV for a large but experimentally consistent asymmetry to be present today. We also …