The process μ→νeeνˉμ\mu \to \nu_{e}e\bar{\nu}_{\mu} in the 2HDM with flavor changing neutral currents

We consider the process $\mu \to \nu_{e}e\bar{\nu}_{\mu}$in the framework of a two Higgs doublet model with flavor changing neutral currents (FCNC). Since FCNC generates in turn flavor changing charged currents in the lepton sector, this process appears at tree level mediated by a charged Higgs boson exchange. From the experimental upper limit for this decay, we obtain the bound $| \xi_{\mu e}/m_{H^{\pm}}| \leq 3.8\times 10^{-3}$ where$\xi_{\mu e}$refers to the mixing between the first and second lepton generations, and $m_{H^{\pm}}$denotes the mass of the charged Higgs boson. This bound is independent on the other free parameters of the model. In particular, for $m_{H^{\pm}}\simeq 100$GeV we get $| \xi_{e\mu}|$ $\lesssim 0.38$Comment: 2 pages, no figure

A Complete Set of Firmware for the TileCal Read-Out Driver

TileCal is the hadronic tile calorimeter of the ATLAS experiment at LHC/CERN. The Read-Out Driver (ROD) is the main component of the TileCal back-end electronics. The ROD is a VME 64x 9u board with multiple programmable devices which requires a complete set of firmware. This paper describes the firmware and functionalities of all these programmable devices, especially the DSP Processing Units daughterboards where the data processing takes place

Optical Buffer 1:16

This document is a manual describing the functionality and the operation of the Optical Buffer 1:16 (OB). The OB was specially designed to repeat optical signals during the TileCal Read-Out drivers (ROD) production. The data generated in one Optical Multiplexer Board (OMB) 6U prototypes were repeated with two OB in order to inject data simultaneously to four RODs

Totally Laparoscopic Roux-en-Y Duct-to-Mucosa Pancreaticojejunostomy After Middle Pancreatectomy A Consecutive Nine-case Series at a Single Institution

To present the results of a series of laparoscopic middle pancreatectomies with roux-en-Y duct-to-mucosa pancreaticojejunostomy. SUMMARY OF BACKGROUND DATA: Middle pancreatectomy makes it possible to preserve pancreatic parenchyma in the resection of lesions that traditionally have been treated by distal splenopancreatectomy or cephalic duodenopancreatectomy. The laparoscopic approach could minimize the invasiveness of the procedure and enhance the benefits of middle pancreatectomy. METHODS: From March 2005 to October 2007, 9 consecutive patients with benign or low malignant potential lesions in the pancreatic neck or body underwent surgery. Laparoscopic middle pancreatectomy with a roux-en-Y duct-to-mucosa pancreaticojejunostomy was planned on all of them. In the first 2 patients, the pancreas was transected by endostapler; in the last 7, the staple line was reinforced with absorbable polymer membrane. RESULTS: The intervention was concluded laparoscopically in every case except 1 (laparoscopic-assisted) in which pancreaticojejunostomy was performed by means of minilaparotomy. Mortality was 0% and perioperative morbidity was 33%, (fistula of the cephalic stump in the first 2 patients (22%)). The pancreaticojejunostomy fistula rate was 0%. The median postoperative hospital stay was 5 days (range, 3-41). In the last 7 patients, in which pancreas was transected with staple line reinforcement material there were no stump fistulas; morbidity decreased to 14% and the median hospital stay was 4 days (range, 3-30). CONCLUSIONS: Laparoscopic middle pancreatectomy is feasible and safe. Duct-to-mucosa pancreaticojejunostomy can be performed safely using this approach. The method of pancreatic transection seems to be decisive in the incidence of cephalic stump fistulas

Monte Carlo Performance of the TileCal Low pT Muon Identification Algorithm

This note describes the TileCal standalone low pT muon identification algorithm (TileMuId) developed to contribute to the Level-2 trigger. This algorithm is based on the characteristic muon energy deposition inside the calorimeter. The implementation of this algorithm in the core of the Digital Signal Processors (DSPs) in the TileCal Read-Out Drivers (RODs) is also discussed in this paper. The TileMuId performance with Monte Carlo data from single muons and bb events is shown in terms of efficiencies and fraction of fakes for both a fully Level-2 version and a ROD-based version of the algorithm

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector

Results of a search for H → τ τ decays are presented, based on the full set of proton-proton collision data recorded by the ATLAS experiment at the LHC during 2011 and 2012. The data correspond to integrated luminosities of 4.5 fb−1 and 20.3 fb−1 at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV respectively. All combinations of leptonic (τ → `νν¯ with ` = e, µ) and hadronic (τ → hadrons ν) tau decays are considered. An excess of events over the expected background from other Standard Model processes is found with an observed (expected) significance of 4.5 (3.4) standard deviations. This excess provides evidence for the direct coupling of the recently discovered Higgs boson to fermions. The measured signal strength, normalised to the Standard Model expectation, of µ = 1.43 +0.43 −0.37 is consistent with the predicted Yukawa coupling strength in the Standard Model