The measurements of the anomalous like-sign dimuon charge asymmetry in ppˉp \bar{p} collisions by the D\O\ Collaboration

In this short review we present the history, an overview of the analysis, and some personal comments on the anomalous like-sign dimuon charge asymmetry measurements by the D\O\ Collaboration.Comment: 6 pages, 2 figures. arXiv admin note: text overlap with arXiv:1109.143

Trying to understand dark matter

We present some "back-of-the-envelope" calculations to try to understand cold dark matter, its searches, and extensions of the Standard Model. Some of the insights obtained from this exercise may be useful.Comment: 16 pages, 1 figur

Constraints on neutrino masses from Baryon Acoustic Oscillation measurements

From 21 independent Baryon Acoustic Oscillation (BAO) measurements we obtain the following sum of masses of active Dirac or Majorana neutrinos: $\sum m_\nu = 0.711 - 0.335 \cdot \delta h + 0.050 \cdot \delta b \pm 0.063 \textrm{ eV,}$ where $\delta h \equiv (h - 0.678) / 0.009$ and $\delta b \equiv (\Omega_b h^2 - 0.02226) / 0.00023$. This result may be combined with independent measurements that constrain the parameters $\sum m_\nu$, $h$, and $\Omega_b h^2$. For $\delta h = \pm 1$ and $\delta b = \pm 1$, we obtain $m_\nu < 0.43$ eV at 95\% confidence.Comment: 2 pages, 0 figure

Measurements of the cosmological parameters Ωm\Omega_m, Ωk\Omega_k, Ωde(a)\Omega_\textrm{de}(a), H0H_0, and ∑mν\sum m_\nu

From Baryon Acoustic Oscillation measurements with Sloan Digital Sky Survey SDSS DR14 galaxies, and the acoustic horizon angle $\theta_*$ measured by the Planck Collaboration, we obtain $\Omega_m = 0.2724 \pm 0.0047$, and $h + 0.020 \cdot \sum{m_\nu} = 0.7038 \pm 0.0060$, assuming flat space and a cosmological constant. We combine this result with the 2018 Planck `TT,TE,EE$+$lowE$+$lensing' analysis, and update a study of $\sum m_\nu$ with new direct measurements of $\sigma_8$, and obtain $\sum m_\nu = 0.27 \pm 0.08$ eV assuming three nearly degenerate neutrino eigenstates. Measurements are consistent with $\Omega_k = 0$, and $\Omega_\textrm{de}(a) = \Omega_\Lambda$ constant.Comment: 11 pages, 6 figure

Trying to understand mass

We try to understand how particles acquire mass in general, and in particular, how they acquire mass in the standard model and beyond.Comment: 19 pages, 5 figure

Anomalous dimuon charge asymmetry in proton-antiproton collisions

We present an overview of the measurements of the like-sign dimuon charge asymmetry by the DO Collaboration at the Fermilab Tevatron proton-antiproton Collider. The results differ from the Standard Model prediction of CP violation in mixing and interference of B^0 and B^0_s by 3.6 standard deviations.Comment: 6 pages, 6 figures, Proceedings of Rencontres de Moriond, EW session, 201

Ratio between two Λ\Lambda and Λˉ\bar{\Lambda} production mechanisms in pp scattering

We consider $\Lambda$ and $\bar{\Lambda}$ production in a wide range of proton scattering experiments. The produced $\Lambda$ and $\bar{\Lambda}$ may or may not contain a diquark remnant of the beam proton. The ratio of these two production mechanisms is found to be a simple universal function $r = [ \kappa/(y_p - y) ]^i$ of the rapidity difference $y_p - y$ of the beam proton and the produced $\Lambda$ or $\bar{\Lambda}$, valid over four orders of magnitude, from $r \approx 0.01$ to $r \approx 100$, with $\kappa = 2.86 \pm 0.03 \pm 0.07$, and $i = 4.39 \pm 0.06 \pm 0.15$.Comment: 2 pages, 2 figure

On CP violation and the measurement of the dimuon charge asymmetry at hadron colliders

B factories measure the CP violation parameter of B^0 Bbar^0 mixing and decay. Hadron colliders measure the dimuon charge asymmetry of an admixture of B hadrons. In this note we discuss a subtle point on how the CP violation parameter of B^0_s Bbar^0_s mixing and decay can be extracted from these measurements.Comment: 7 pages, 0 figure

Like-sign dimuon charge asymmetry in the decay of B B-bar pairs

We discuss the CP-violating dimuon charge asymmetry of events p p-bar ---> B B-bar X ---> mu mu X in the Standard Model. Our conclusion is that the asymmetry is larger than previously expected and may reach a few percent for the (B_d^0, B-bar_d^0) system. The analysis is also extended to the Two Higgs Doublet Model (Model II).Comment: 9 pages, 3 Postscript figure

Understanding the like-sign dimuon charge asymmetry in ppˉp \bar{p} collisions

The D\O\ collaboration has measured the like-sign dimuon charge asymmetry in $p \bar{p}$ collisions at the Fermilab Tevatron collider. The result is significantly different from the standard model expectation of CP violation in mixing. In this paper we consider the possible causes of this asymmetry and identify one standard model source not considered before. It decreases the discrepancy of the like-sign dimuon charge asymmetry with the standard model prediction, although does not eliminate it completely.Comment: 7 pages, 0 figure