Searches for Majorana Neutrinos and Direct Searches for Exotics at LHCb

These proceedings present the LHCb results on Majorana neutrino searches and direct production of exotic particles using the data collected during Run I of LHC. For the former, Majorana neutrinos are searched for both on-shell and off-shell in $B$ and $D$ decays to final states with two same-sign muons. For the latter, different types of new particles are studied profiting the unique coverage of LHCb with respect to other detectors.Comment: 9 pages, 27 figures. To be published in the LISHEP 2015 proceeding

Muon Identification in the LHCb experiment

A short summary of the LHCb muon identification procedure is given in this article. First, the muon system of LHCb is presented, together with some examples of physics measurements of the experiment where the muon identification is crucial. Then, the muon identification algorithm is introduced in three single steps. With this, the efficiency vs. misidentification rate is shown for MC simulated data. The way this method will be calibrated with real data is also seen. Finally, some preliminary muon identification results with proton-proton collisions at sqrt(s) = 900 GeV are presented.Comment: Proceedings for the Moriond 2010 E

Sitio web sobre el acelerador lhc: recurso para el aula de “ciencias del mundo contemporáneo” lhc-closer.es

SITIO WEB SOBRE EL ACELERADOR LHC: RECURSOPARA EL AULA DE “CIENCIAS DEL MUNDOCONTEMPORÁNEO”lhc-closer.e

Search for the rare decays B0 (s) - μ+μ− and K0 S - μ+μ− with 1 fb−1 at LHCb

This thesis is devoted to the explanation of the searches for the very rare decays B0 (s) ! + and K0 S ! + , performed using the 1 fb1 of data taken by LHCb during 2011 from the LHC proton{ proton collisions at an energy of p s=7 TeV. The most relevant theory aspects concerning these searches will be presented. Furthermore, the LHCb experiment will be described, and some of its most interesting results in the rare decays area reported. The B0 (s) ! + search has not resulted in any signal excess above background, but has produced world best upper limits in the branching ratios of both channels: B(B0 ! + ) < 1:0 109 and B(B0 s ! + ) < 4:5 109, both at 95% con dence level. Finally, no signi cant signal excess has been found in the search for K0 S ! + neither, and again an upper limit on its branching ratio has been set: B(K0 S ! + ) < 11:2 109 at 95% con dence level. This upper limit is a factor of 35 better than the previous world best

Discovering True Muonium at LHCb

We study the potential of the LHCb experiment to discover, for the first time, the $\mu^+\mu^-$ true muonium bound state. We propose a search for the vector $1^3S_1$ state, $\mathcal{T\!M}$, which kinetically mixes with the photon and dominantly decays to $e^+e^-$. We demonstrate that a search for $\eta \to \gamma \mathcal{T\!M}$, $\mathcal{T\!M}\to e^+e^-$ in a displaced vertex can exceed a significance of 5 standard deviations assuming statistical uncertainties. We present two possible searches: an inclusive search for the $e^+e^-$ vertex, and an exclusive search which requires an additional photon and a reconstruction of the $\eta$ mass.Comment: 12 pages, 5 figures; v2: edits from comments and review, matched to PRD versio

A comparative study of calibration methods for low-cost ozone sensors in IoT platforms

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper shows the result of the calibration process of an Internet of Things platform for the measurement of tropospheric ozone (O 3 ). This platform, formed by 60 nodes, deployed in Italy, Spain, and Austria, consisted of 140 metal–oxide O 3 sensors, 25 electro-chemical O 3 sensors, 25 electro-chemical NO 2 sensors, and 60 temperature and relative humidity sensors. As ozone is a seasonal pollutant, which appears in summer in Europe, the biggest challenge is to calibrate the sensors in a short period of time. In this paper, we compare four calibration methods in the presence of a large dataset for model training and we also study the impact of a limited training dataset on the long-range predictions. We show that the difficulty in calibrating these sensor technologies in a real deployment is mainly due to the bias produced by the different environmental conditions found in the prediction with respect to those found in the data training phase.Peer ReviewedPostprint (author's final draft

Exclusive displaced hadronic signatures in the LHC forward region

The LHCb detector provides accurate vertex reconstruction and hadronic particle identification, which make the experiment an ideal place to look for light long-lived particles (LLP) decaying into Standard Model (SM) hadrons. In contrast with the typical search strategy relying on energetic jets and a high multiplicity of tracks from the LLP decay, LHCb can identify LLPs in exclusive, specific hadronic final states. To illustrate the idea, we study the sensitivity of LHCb to an exotic Higgs decay h → SS, followed by the displaced decay of GeV-scale scalars into charged kaons S → K+K−. We show that the reconstruction of kaon vertices in narrow invariant mass windows can efficiently eliminate the combinatorial backgrounds from B-meson decays. While the same signal is extremely difficult to probe in the existing displaced jet searches at ATLAS/CMS, the LHCb search we propose can probe the branching ratio BR(h → SS) down to 0.1% (0.02%) level with 15 (300) fb−1 of data. We also apply this projected bound to two scenarios with Higgs portal couplings, where the scalar mediator S either couples to a) the SM quarks only, or b) to both quarks and leptons in the minimal flavor violation paradigm. In both scenarios we compare the reach of our proposed search with the expected constraints from ATLAS and CMS on the invisible Higgs width and with the constraints from rare B-decays studies at LHCb. We find that for 1 GeV < mS < 2 GeV and 0.5 mm . cτ . 10 mm our proposed search will be competitive with the ATLAS and CMS projections, while at the same time providing crucial information of the hadronic interactions of S, which can not be obtained from the indirect measurement of the Higgs invisible width.The work of XCV is supported by MINECO (Spain) through the Ram´on y Cajal program RYC-2016-20073 and by XuntaGal under the ED431F 2018/01 project. YT is supported in part by the National Science Foundation under Grant Number PHY-1620074. YT would like to thank Aspen Center for Physics for hospitality during the completion of this work, which is supported by National Science Foundation grant PHY-1607611.S

Sitio web sobre el acelerador LHC: recurso para el aula de “Ciencias del Mundo Contemporáneo”

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Aromatic interactions of allenyl-anthracene derivatives with pi-electron acceptor molecules: an experimental and computational study

Electrostatic effects play an important role in aromatic interactions towards molecular recognition. Anthraceno-allenophanes are cyclic π-conjugated aromatic systems able to recognise complementary molecules through aromatic interactions. A computational and experimental study has shown that the dispersive contribution is the predominant stabilising term in the interaction of an allenyl-anthracene derivative with relevant π-acceptor molecules, such as pentafluorophenol, picric acid and 2,3-dichloro-5,6-dicyano-1,4-quinone.Agencia Estatal de Investigación | Ref. CTQ2017-85919-RXunta de Galicia | Ref. ED431C 2017/7Xunta de Galicia | Ref. ED431E 2018/07Xunta de Galicia | Ref. ED481B 2016/166-