相关论文: Neutralino annihilation beyond leading order
We study the neutralino decay in the supersymmetric extra U(1) models which can solve the $\mu$-problem. In these models the neutralino sector is extended at least into six components by an extra U(1) gaugino and a superpartner of a singlet…
How large can the dark matter self-annihilation rate in the late universe be? This rate depends on (rho_DM/m_chi)^2 <sigma_A v>, where rho_DM/m_chi is the number density of dark matter, and the annihilation cross section is averaged over…
We construct the S-wave part of the electromagnetic vector annihilation current to O(alpha_s v^2)$ on the lattice for heavy quarks whose dynamics are described by the NRQCD action, where v is the non-relativistic quark velocity. The lattice…
General relativistic calculations are made of neutrino-antineutrino annihilation into electron-positron pairs near the surface of a neutron star. It is found that the efficiency of this process is enhanced over the Newtonian values up to a…
In this paper we examine thoroughly the single (anti-)top quark production associated with a lightest neutralino at the possible CERN Large Hadron Electron Collider (LHeC). We calculate the full next-to-leading order (NLO) QCD corrections…
The lightest neutralino of R-parity conserving supersymmetric models serves as a compelling candidate to account for the presence of cold dark matter in the universe. In the minimal supergravity (mSUGRA) model, a relic density can be found…
We calculate the next-to-next-to-leading-order (NNLO) perturbative corrections to $P$-wave quarkonia annihilation decay to two photons, in the framework of nonrelativistic QCD (NRQCD) factorization. The order-$\alpha_s^2$ short-distance…
The 1-loop computation of the processes $\tchi_i \tchi_j \to \gamma Z$ has been performed at an arbitrary c.m. energy for any pair of MSSM neutralinos. As an application suitable for Dark Matter (DM) searches, the neutralino-neutralino…
We discuss a modification of the next-to-next-to-leading order (NNLO) subtraction scheme based on the residue-improved sector decomposition that reduces the number of double-real emission sectors from five to four. In particular, a sector…
The extracted value of the relic density has reached the few per-cent level precision. One can therefore no longer content oneself with calculations of this observable where the annihilation processes are computed at tree-level, especially…
Semi-annihilation is a generic feature of dark matter theories stabilised by symmetries larger than a $Z_2$. It contributes to thermal freeze out, but is irrelevant for direct and collider searches. This allows semi-annihilating dark matter…
We compute the next-to-next-to-leading order (NNLO) QCD corrections to the thrust distribution in electron-positron annihilation. The corrections turn out to be sizable, enhancing the previously known next-to-leading order prediction by…
We add to the Standard Model a new fermion $\chi$ with minimal baryon number 1/3. Neutron decay $n \to \chi\chi\chi$ into non-relativistic $\chi$ can account for the neutron decay anomaly, compatibly with bounds from neutron stars. $\chi$…
We compute analytically the tree-level annihilation rates of a collection of non-relativistic neutralino and chargino two-particle states in the general MSSM, including the previously unknown off-diagonal rates. The results are…
We present a calculation of next-to-leading-order (NLO) QCD corrections to total hadronic production cross sections and to light-hadron-decay rates of heavy quarkonium states. Both colour-singlet and colour-octet contributions are included.…
We derive a full set of exact, analytic expressions for the annihilation of the lightest neutralino pairs into all two-body tree-level final states in the framework of minimal supersymmetry. We make no simplifying assumptions about the…
We present the full $\mathcal{O}(\alpha_s)$ supersymmetric QCD corrections for gaugino annihilation and co-annihilation into light and heavy quarks in the Minimal Supersymmetric Standard Model (MSSM). We demonstrate that these channels are…
In the indirect detection of dark matter through its annihilation products, the signals depend on the square of the dark matter density, making precise knowledge of the distribution of dark matter in the Universe critical for robust…
A resonance in the neutralino-nucleus elastic scattering cross section is usually purported when the neutralino-sbottom mass difference m_sbottom-m_chi is equal to the bottom quark mass m_b ~ 4 GeV. Such a scenario has been discussed as a…
We calculate the complete next-to-leading order QCD corrections to the three-body decay of gluino into top-pair associated with a lightest neutralino in the minimal supersymmetric standard model. We obtain that the LO and NLO QCD corrected…