118911380
Factorization of B decays into two light mesons in soft collinear effective theory
We show that the amplitudes for B decays into two light mesons at leading order in soft-collinear effective theory are factorized to all orders in alpha_s. We construct gauge-invariant four-quark operators by employing the effective theories SCET_I for sqrt{m_b \Lambda} <\mu<m_b, and SCET_II for \mu <sqrt{m_b \Lambda} with Lambda ~0.5 GeV. These operators do not allow gluon exchanges between different sectors of the current and the matrix elements are reduced to the products of current matrix elements. The spectator interactions are also factorized at leading order in SCET and to all orders in alpha_s.
17641368
Factorization and resummation for color octet production
We discuss the production of heavy colored paricles at the Large Hadron Collider (LHC) through gluon-gluon fusion process. A factorization theorem is obtained for this process using Soft Collinear Effective Theory. Our factorization theorem does not depend on any assumptions regarding the physics above the mass of the heavy colored particle. In this sense it is universal. The matching coefficient at the heavy particle mass scale depends however on the unkown physics above that scale and thus it is model dependent. 
Due to the large mass of the heavy colored particle, i.e., the hard scale and near the partonic kinematic threshold for production of such particles a resummation of large logarithms needs to be performed. The resummation is justified due to the dominance of the gluon distribution function at small $x$. For phenomenological purposes we utilize the Manohar-Wise model.
13093742
Semi-inclusive hadronic B decays in the endpoint region
We consider in the soft-collinear effective theory semi-inclusive hadronic $B$ decays, $B\ensuremath{\rightarrow}XM$, in which an energetic light meson $M$ near the endpoint recoils against an inclusive jet $X$. We focus on a subset of decays where the spectator quark from the $B$ meson ends up in the jet. The branching ratios and direct $CP$ asymmetries are computed to next-to-leading order accuracy in ${\ensuremath{\alpha}}_{s}$ and to leading order in $1/{m}_{b}$. The contribution of charming penguins is extensively discussed, and a method to extract it in semi-inclusive decays is suggested. Subleading $1/{m}_{b}$ corrections and $SU(3)$ breaking effects are discussed.
118701906
Nonperturbative charming penguin contributions to isospin asymmetries in radiative B decays
Recent experimental data on the radiative decays B{yields}V{gamma}, where V is a light vector meson, find small isospin violation in B{yields}K*{gamma} while isospin asymmetries in B{yields}{rho}{gamma} are of order 20%, with large uncertainties. Using soft-collinear effective theory, we calculate isospin asymmetries in these radiative B decays up to O(1/m{sub b}), also including O(v{alpha}{sub s}) contributions from nonperturbative charming penguins (NPCP). In the absence of NPCP contributions, the theoretical predictions for the asymmetries are a few percent or less. Including the NPCP can significantly increase the isospin asymmetries for both B{yields}V{gamma} modes. We also consider the effect of the NPCP on the branching ratio and CP asymmetries in B{sup {+-}}{yields}V{sup {+-}}{gamma}.
118447534
Proper factorization theorems in high-energy scattering near the endpoint
A bstractConsistent factorization theorems in high-energy scattering near the threshold are presented in the framework of the soft-collinear effective theory. Traditional factorization theorem separates the soft and collinear parts successfully, but a final step should be supplemented if each part encounters infrared divergence. We present factorization theorems in which the infrared divergences appear only in the parton distribution functions and the infrared divergence is removed by carefully separating and reorganizing collinear and soft parts. The underlying physical idea is to isolate and remove the soft contributions systematically from the collinear part in loop corrections order by order. After this procedure, each factorized term in the scattering cross sections is free of infrared divergence, and can be safely computed using perturbation theory. This factorization procedure can be applied to various high-energy scattering processes. We show factorization theorems in Drell-Yan processes, deep inelastic scattering and Higgs production near the endpoint.
53724420
Soft Wilson lines in the soft-collinear effective theory
The effects of the soft gluon emission in hard scattering processes at the phase boundary are resummed in the soft-collinear effective theory (SCET). In SCET, the soft gluon emission is decoupled from the energetic collinear part, and is obtained by the vacuum expectation value of the soft Wilson-line operator. The form of the soft Wilson lines is universal in deep inelastic scattering, in the Drell-Yan process, in the jet production from e{sup +}e{sup -} collisions, and in the {gamma}*{gamma}*{yields}{pi}{sup 0} process, but its analytic structure is slightly different in each process. The anomalous dimensions of the soft Wilson-line operators for these processes are computed along the lightlike path at leading order in SCET and to first order in {alpha}{sub s}, and the renormalization group behavior of the soft Wilson lines is discussed.
120458097
A Study of the Azimuthal Decorrelation between Jets with Large Rapidity Separation
109775896
Results of radiation test of the cathode front-end board for CMS endcap muon chambers
Abstract After a brief overview of the CMS EMU electronics system, results on radiation induced single event effects, total ionization dose and displacement effects will be reported. These results are obtained by irradiating the components on electronics boards with 63 MeV protons and 1 MeV neutrons. During the proton irradiation, the electronics board was fully under power, all components on the board were active and the data were read out in the same way as designed for CMS. No deterioration of analog performance for each of the three CMOS ASICs on the tested board was observed, up to a dose of 10 krad . Each of the tested FPGAs survived beyond the dose of 30 krad . No single event latch-up was detected for the CMOS ASICs up to a proton fluence of 2×10 12 cm −2 . Single Event Upsets (SEU) in FPGAs were detected and their cross-sections measured. SEU mitigation with triple module redundancy and voting was implemented and tested.