Searches for New Physics at CMS

The first searches for New Physics with the CMS detector at the LHC are presented. The discussed analyses are based on the data sample recorded in 2010 at a centre-of-mass energy of 7TeV, which corresponds to an integrated luminosity of about 35 pb−1. Searches for excited vector bosons, leptoquarks, extra dimensions as well as for supersymmetry in different final states are presented. No significant deviations from Standard Model expectations have been observed and thus limits on the parameter space of different New Physics scenarios are derived

Fit to Moments of Inclusive B->Xc lv and B-> Xs gamma Decay Distributions using Heavy Quark Expansions in the Kinetic Scheme

We present a fit to measured moments of inclusive distributions in B->Xc lv and B-> Xs gamma decays to extract values for the CKM matrix element |Vcb|, the b- and c-quark masses, and higher order parameters that appear in the Heavy Quark Expansion. The fit is carried out using theoretical calculations in the kinetic scheme and includes moment measurements of the Babar, Belle, CDF, CLEO and DELPHI collaborations for which correlation matrices have been published. We find |Vcb| = (41.96 +- 0.23(exp) +- 0.35(HQE) +- 0.59(Gamma_SL)) 10^-3 and m_b = 4.590 +- 0.025(exp) +- 0.30(HQE) GeV where errors are experimental and theoretical respectively. We also derive values for the heavy quark distribution function parameters m_b and \mu_\pi^2 in different theoretical schemes that can be used as input for the determination of |Vub|.Comment: 13 pages, 6 figures. v3: Fig 1+2 show absolute values for moments and fit rather than the difference. Updated some references. v2: Updated to include Belle photon moments and PDG 2005 lifetime. Included extrapolation factors for the BR(B->Xs gamma) to 1.6 Gev based on the HQE parameters from the fit and added an updated OPE expression for |Vub

RG-improved single-particle inclusive cross sections and forward-backward asymmetry in ttˉt\bar t production at hadron colliders

We use techniques from soft-collinear effective theory (SCET) to derive renormalization-group improved predictions for single-particle inclusive (1PI) observables in top-quark pair production at hadron colliders. In particular, we study the top-quark transverse-momentum and rapidity distributions, the forward-backward asymmetry at the Tevatron, and the total cross section at NLO+NNLL order in resummed perturbation theory and at approximate NNLO in fixed order. We also perform a detailed analysis of power corrections to the leading terms in the threshold expansion of the partonic hard-scattering kernels. We conclude that, although the threshold expansion in 1PI kinematics is susceptible to numerically significant power corrections, its predictions for the total cross section are in good agreement with those obtained by integrating the top-pair invariant-mass distribution in pair invariant-mass kinematics, as long as a certain set of subleading terms appearing naturally within the SCET formalism is included.Comment: 55 pages, 14 figures, 6 table

Measurement of the quasi-elastic axial vector mass in neutrino-oxygen interactions

The weak nucleon axial-vector form factor for quasi-elastic interactions is determined using neutrino interaction data from the K2K Scintillating Fiber detector in the neutrino beam at KEK. More than 12,000 events are analyzed, of which half are charged-current quasi-elastic interactions nu-mu n to mu- p occurring primarily in oxygen nuclei. We use a relativistic Fermi gas model for oxygen and assume the form factor is approximately a dipole with one parameter, the axial vector mass M_A, and fit to the shape of the distribution of the square of the momentum transfer from the nucleon to the nucleus. Our best fit result for M_A = 1.20 \pm 0.12 GeV. Furthermore, this analysis includes updated vector form factors from recent electron scattering experiments and a discussion of the effects of the nucleon momentum on the shape of the fitted distributions.Comment: 14 pages, 10 figures, 6 table