118656803
Realistic flipped SU(5) from orbifold SO(10)
We propose a realistic flipped SU(5) model derived from a five-dimensional orbifold SO(10) model. The Standard Model (SM) fermion masses and mixings are explained by combining the traditional Froggatt-Nielsen mechanism with the five-dimensional wave function profiles of the SM fermions. Employing tree-level spontaneous R-symmetry breaking in the hidden sector and extra(ordinary) gauge mediation, we obtain realistic supersymmetry breaking soft mass terms with non-vanishing gaugino masses. Including the messenger fields at the intermediate scale and Kaluza-Klein states at the compactification scale, we study gauge coupling unification. We show that the SO(10) unified gauge coupling is very strong and the unification scale can be much higher than the compactification scale. We briefly discuss proton decay as well.
119201106
Semi-direct Gauge-Yukawa mediation
We propose semi-direct Gauge-Yukawa mediation of supersymmetry (SUSY) breaking. The messenger fields mediating SUSY breaking to the visible sector do not directly couple with the goldstino field, and instead they have gauge and Yukawa interactions with some primary messenger fields which couple directly with the goldstino fields. From the explicit Feynman diagram calculations for the SUSY breaking soft masses, we find that the SUSY particle spectra can be realistic. Especially, this generalization of semi-direct gauge mediation solves the massless gaugino mass problem since the holomorphic soft mass terms of the messenger fields can be generated by Yukawa couplings. We also provide some arguments that this scenario can be realized naturally in some dynamical SUSY-breaking models such as the ISS-like model.
119232543
On naturalness of the MSSM and NMSSM
A bstractWith a bottom-up approach, we consider naturalness in the MSSM and NMSSM. Assuming the light stops, the LHC gluino search implies that the degree of fine tuning in both models is less than 2.5%. Taking the LHC hints for the SM-like Higgs boson mass mh ~ 125 GeV seriously, we find that naturalness will favor the NMSSM. We study the Higgs boson mass for several scenarios in the NMSSM: (1) A large λ and the doublet-singlet Higgs boson mixing effect pushing upward or pulling downward mh. The former case can readily give the di-photon excess of the Higgs boson decay whereas the latter case can not. However, we point out that the former case has a new large fine-tuning related to strong λ−RGE running effect and vacuum stability. (2) A small λ and the mixing effect pushing mh upward. Naturalness status becomes worse and no significant di-photon excess can be obtained. In these scenarios, the lightest supersymmetric particle (LSP) as a dark matter candidate is strongly disfavored by the XENON100 experiment. Even if the LSP can be a viable dark matter candidate, there does exist fine-tuning. The above naturalness evaluation is based on a high mediation scale for supersymmetry breaking, whereas for a low mediation scale, fine-tuning can be improved by about one order.
119234621
A Rediatively Light Stop Saves the Best Global Fit for Higgs Boson Mass and Decays
The LHC discovered the Standard Model (SM) like Higgs boson with mass around 125 GeV. However, there exist hints of deviations from Higgs decays. Including the Tevatron data, the deviations can be explained by the extremely mixed stop sector in the sense of best global fit (BGF). We analyze the relations among the competing reduced coupling hGG, Higgs boson mass,and LHC stop mass m_{\wt t_1} lower bound at the tree- and one-loop level. In particular, we point out that we use the light stop running mass in the Higgs boson mass calculation while the light stop pole mass in the Higgs decays. So the gluino radiative correction on the light stop mass plays the crucial role. Its large negative correction saves the GBF in the Minimal Supersymmetric SM (MSSM) and the next to the MSSM (NMSSM) constrained by the perturbativity. Moreover, a light stop is predicted: in the MSSM if we set the gluino mass M_3\lesssim4 TeV, we have m_{\wt t_1}<m_t; while in the NMSSM, imposing the least tuning condition we get m_{\wt t_1}\simeq130 GeV for M_3\simeq1.5 TeV.
119216010
Asymmetric origin for gravitino relic density in the hybrid gravity-gauge mediated supersymmetry breaking
A bstractWe propose the hybrid gravity-gauge mediated supersymmetry breaking where the gravitino mass is about several GeV. The strong constraints on supersymmetry viable parameter space from the CMS and ATLAS experiments at the LHC can be relaxed due to the heavy colored supersymmetric particles, and it is consistent with null results in the dark matter (DM) direct search experiments such as XENON100. In particular, the possible maximal flavor and CP violations from the relatively small gravity mediation may naturally account for the recent LHCb anomaly. In addition, because the gravitino mass is around the asymmetric DM mass, we propose the asymmetric origin of the gravitino relic density and solve the cosmological coincident problem on the DM and baryon densities ΩDM : ΩB ≈ 5 : 1. The gravitino relic density arises from asymmetric metastable particle (AMP) late decay. However, we show that there is no AMP candidate in the minimal supersymmetric Standard Model (SM) due to the robust gaugino/Higgsino mediated wash-out effects. Interestingly, AMP can be realized in the well motivated supersymmetric SMs with vector-like particles or continuous U(1)R symmetry. Especially, the lightest CP-even Higgs boson mass can be lifted in the supersymmetric SMs with vector-like particles.
118503601
Brightening the (130 GeV) Gamma-Ray Line
The gamma-ray line from dark matter (DM) annihilation is too weak to observe, but its observation will uncover much information, e.g., the DM mass and an anomalously large annihilation rate ∼ 0.1 pb into di-photon. In this work, we construct a minimal effective theory (EFT) incorporating DM and heavier charged particles. A large annihilation rate is obtained from operator coefficients with resonance or strong coupling enhancement.The EFT is stringently constrained by the XENON100 and WMAP data. Without resonance, Dirac DM or colored charged particles are ruled out. It is pointed out that the di-gluon mode may correctly determine the DM relic density. Interestingly, this framework also provides an origin for the Higgs di-photon excess at the LHC. We apply the general analysis to the NMSSM, which can elegantly interpret the tentative 130 GeV gamma-ray line. A top-window model is also proposed to explain the gamma-ray line.
118363530
QCD EVOLUTION OF NAIVE-TIME-REVERSAL-ODD QUARK-GLUON CORRELATION FUNCTIONS
In this talk, we examine the existing calculations of QCD evolution kernels for the scale dependence of two sets of twist-3 quark-gluon correlation functions, Tq,F(x, x) and $T^{(\sigma)}_{q, F}(x, x)$, which are the first transverse-momentum-moment of the naive-time-reversal-odd Sivers and Boer-Mulders function, respectively. The evolution kernels at the leading order in strong coupling constant αs were derived by several groups with apparent differences. We identify the sources of discrepancies and are able to reconcile the results from various groups.
118412729
Evolution of twist-3 multiparton correlation functions relevant to single transverse-spin asymmetry
We construct two sets of twist-3 correlation functions that are responsible for generating the novel single transverse-spin asymmetry in the QCD collinear factorization approach. We derive evolution equations for these universal three-parton correlation functions. We calculate evolution kernels relevant to the gluonic pole contributions to the asymmetry at the order of {alpha}{sub s}. We find that all evolution kernels are infrared safe as they should be and have a lot in common with the Dokshitzer-Gribov-Lipatov-Alterelli-Parisi evolution kernels of unpolarized parton distributions. By solving the evolution equations, we explicitly demonstrate the factorization scale dependence of these twist-3 correlation functions.
118726740
Single transverse-spin asymmetry for D -meson production in semi-inclusive deep inelastic scattering
We study the single transverse-spin asymmetry for open charm production in the semi-inclusive lepton-hadron deep inelastic scattering. We calculate the asymmetry in terms of the QCD collinear factorization approach for D mesons at high enough P{sub hperpendicular} and find that the asymmetry is proportional to the twist-three trigluon correlation function in the proton. With a simple model for the trigluon correlation function, we estimate the asymmetry for both COMPASS and eRHIC kinematics and discuss the possibilities of extracting the trigluon correlation function in these experiments.
118463588
Transverse momentum broadening of vector boson production in high energy nuclear collisions
We calculate in perturbative QCD the transverse momentum broadening of vector boson production in high energy nuclear collisions. We evaluate the effect of initial-state parton multiple scattering for the production of the Drell-Yan virtual photon and W/Z bosons. We calculate both the initial- and final-state multiple scattering effect for the production of heavy quarkonia and their transverse momentum broadening in both nonrelativistic QCD and the color evaporation model of quarkonium formation. We find that J/{psi} and {upsilon} broadening in hadron-nucleus collision is close to 2C{sub A}/C{sub F} times the corresponding Drell-Yan broadening, which gives a good description of existing Fermilab data. Our calculations are also consistent with Relativistic Heavy Ion Collider data on J/{psi} broadening in relativistic heavy ion collisions. We predict the transverse momentum broadening of vector boson (J/{psi}, {upsilon}, and W/Z) production in relativistic heavy ion collisions at the Large Hadron Collider and discuss the role of the vector boson broadening in diagnosing medium properties.
119231626
Low-mass lepton pair production at large transverse momentum
We study the transverse momentum distribution of low-mass lepton pairs produced in hadronic scattering, using the perturbative QCD factorization approach. We argue that the distribution at large transverse momentum, Q{sub T}>>Q, with the pair's invariant mass Q as low as Q{approx}{lambda}{sub QCD}, can be systematically factorized into universal parton-to-lepton pair fragmentation functions, parton distributions, and perturbatively calculable partonic hard parts evaluated at a short-distance scale {approx}O(1/Q{sub T}). We introduce a model for the input lepton pair fragmentation functions at a scale {mu}{sub 0}{approx}1 GeV, which are then evolved perturbatively to scales relevant at the Relativistic Heavy Ion Collider. Using the evolved fragmentation functions, we calculate the transverse momentum distributions in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions at the Relativistic Heavy Ion Collider. We also discuss the sensitivity of the transverse momentum distribution of low-mass lepton pairs to the gluon distribution.