45811522
A framework to create customised LHC analyses within CheckMATE
Checkmate  is a framework that allows the user to conveniently test simulated BSM physics events against current LHC data in order to derive exclusion limits. For this purpose, the data runs through a detector simulation and is then processed by a user chosen selection of experimental analyses. These analyses are all defined by signal regions that can be compared to the experimental data with a multitude of statistical tools. 
 
Due to the large and continuously growing number of experimental analyses available, users may quickly find themselves in the situation that the study they are particularly interested in has not (yet) been implemented officially into the Checkmate  framework. However, the code includes a rather simple framework to allow users to add new analyses on their own. This document serves as a guide to this. 
 
In addition, Checkmate  serves as a powerful tool for testing and implementing new search strategies. To aid this process, many tools are included to allow a rapid prototyping of new analyses. 
 
Website: http://checkmate.hepforge.org/ 
Program summary 
Program title: CheckMATE, AnalysisManager 
 
Catalogue identifier: AEUT_v1_1 
 
Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEUT_v1_1.html 
 
Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland 
 
Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html 
 
No. of lines in distributed program, including test data, etc.: 181436 
 
No. of bytes in distributed program, including test data, etc.: 2169369 
 
Distribution format: tar.gz 
 
Programming language: C++, Python. 
 
Computer: PC, Mac. 
 
Operating system: Linux, Mac OS. 
 
Catalogue identifier of previous version: AEUT_v1_0 
 
Journal reference of previous version: Comput. Phys. Comm. 187(2015)227 
 
Classification: 11.9. 
 
External routines: ROOT, Python, Delphes (included with the distribution) 
 
Does the new version supersede the previous version?: Yes 
 
Nature of problem: The LHC has delivered a wealth of new data that is now being analysed. Both ATLAS and CMS have performed many searches for new physics that theorists are eager to test their model against. However, tuning the detector simulations, understanding the particular analysis details and interpreting the results can be a tedious and repetitive task. Furthermore, new analyses are being constantly published by the experiments and might be not yet included in the official CheckMATE distribution. 
 
Solution method: The AnalysisManager within CheckMATE framework allows the user to easily include new experimental analyses as they are published by the collaborations. Furthermore, completely novel analyses can be designed and added by the user in order to test models at higher centre-of-mass energy and/or luminosity. 
 
Reasons for new version: New features, bug fixes, additional validated analyses. 
 
Summary of revisions: New kinematic variables M_CT, M_T2bl, m_T, alpha_T, razor; internal likelihood calculation; missing energy smearing; efficiency tables; validated tau-tagging; improved AnalysisManager and code structure; new analyses; bug fixes. 
 
Restrictions: Only a subset of available experimental results have been implemented. 
 
Additional comments: Checkmate is built upon the tools and hard work of many people. If Checkmate is used in your publication it is extremely important that all of the following citations are included, 
• 
Delphes 3 [1]. 
 
• 
FastJet [2,3]. 
 
• 
Anti-ktkt jet algorithm [4]. 
 
• 
CLss prescription [5]. 
 
• 
In analyses that use the MT2MT2 kinematical discriminant we use the Oxbridge Kinetics Library [6,7] and the algorithm developed by Cheng and Han [8] which also includes the MT2blMT2bl variable [9]. 
 
• 
In analyses that use the MCTMCT family of kinematical discriminants we use MctLib [10,11] which also includes the MCT⊥MCT⊥ and MCTIIMCTII variables [12]. 
 
• 
All experimental analyses that were used to set limits in the study. 
 
• 
The Monte Carlo event generator that was used. 
 
 
Running time: The running time scales about linearly with the number of input events provided by the user. The detector simulation/analysis of 20000 events needs about 50s/1s for a single core calculation on an Intel Core i5-3470 with 3.2 GHz and 8 GB RAM. 
 
References: 
[1] 
J. de Favereau, C. Delaere, P Demin, A. Giammanco, V. Lematre, et al., “DELPHES 3, A modular framework for fast simulation of a generic collider experiment”, 2013. 
 
[2] 
M. Cacciari, G. P Salam, and G. Soyez, “FastJet User Manual”, Eur. Phys. J., vol. C72, p. 1896, 2012. 
 
[3] 
M. Cacciari and G. P Salam, ”Dispelling the N3 myth for the kt jet-finder”, Phys. Lett., vol. B641, pp. 57–61, 2006. 
 
[4] 
M. Cacciari, G. P Salam, and G. Soyez, “The Anti-k(t) jet clustering algorithm”, JHEP, vol. 0804, p. 063, 2008. 
 
[5] 
A. L. Read, “Presentation of search results: the cl’s technique”, Journal of Physics G: Nuclear and Particle Physics, vol. 28, no. 10, p. 2693, 2002. 
 
[6] 
C. Lester and D. Summers, “Measuring masses of semiinvisibly decaying particles pair produced at hadron colliders”, Phys. Lett., vol. B463, pp. 99–103, 1999. 
 
[7] 
A. Barr, C. Lester, and P Stephens, “m(T2): The Truth behind the glamour”, J. Phys., vol. G29, pp. 2343–2363, 2003. 
 
[8] 
H.-C. Cheng and Z. Han, “Minimal Kinematic Constraints and m(T2)”, JHEP, vol. 0812, p. 063, 2008. 
 
[9] 
Y. Bai, H.-C. Cheng, J. Gallicchio, and J. Gu, “Stop the Top Background of the Stop Search”, JHEP, vol. 1207, p. 110, 2012. 
 
[10] 
D. R. Tovey, “On measuring the masses of pair-produced semi-invisibly decaying particles at hadron colliders”, JHEP, vol. 0804, p. 034, 2008. 
 
[11] 
G. Polesello and D. R. Tovey, “Supersymmetric particle mass measurement with the boost-corrected contransverse mass”, JHEP, vol. 1003, p. 030, 2010. 
 
[12] 
K. T. Matchev and M. Park, “A General method for determining the masses of semi-invisibly decaying particles at hadron colliders”, Phys. Rev. Lett., vol. 107, p. 061801, 2011.
54918406
Light stop searches at the LHC with monojet events
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54573705
Constraints on the $R$-parity violating minimal supersymmetric standard model with neutrino masses from multilepton studies at the LHC
In a recent paper, we proposed a hierarchical ansatz for the lepton-number-violating trilinear Yukawa couplings of the R-parity violating minimal supersymmetric standard model. As a result, the number of free parameters in the lepton-number-violating sector was reduced from 36 to 6. Neutrino oscillation data fixes these six parameters, which also uniquely determines the decay modes of the lightest supersymmetric particle and thus governs the collider signature at the LHC. A typical signature of our model consists of multiple leptons in the final state and significantly reduced missing transverse momentum compared to models with R-parity conservation. In this work, we present exclusion limits on our model based on multilepton searches performed at the Large Hadron Collider with 7 TeV center-of-mass energy in 2011 while accommodating a 125 GeV Higgs.
118562999
Amplification of endpoint structure for new particle mass measurement at the LHC
We introduce a new collider variable, M{sub CT2}, named as constransverse mass. It is a mixture of 'stransverse mass (M{sub T2})' and 'contransverse mass (M{sub CT})' variables, where the usual endpoint structure of M{sub T2} distribution can be amplified in the M{sub CT2} basis by a large Jacobian factor which is controlled by a trial missing particle mass. Thus, the M{sub CT2} projection of events increases our observability to measure several important endpoints from new particle decays, which are usually expected to be buried by irreducible backgrounds with various systematic uncertainties at the LHC. In this paper we explain the phenomenology of endpoint amplification in M{sub CT2} projection, and describe how one may employ this variable to measure several meaningful mass constraints of new particles.
15119917
Lepton Mass Matrices and Neutrino Oscillations
We investigate the phenomenological consequences of lepton mass matrices that could be originated from the family permutation symmetry and its suitable breakings. Adopting the recently proposed new mass matrix for the charged lepton mass matrix as well as the Majorana neutrino mass matrix considered before by the present authors, we find that the resulting lepton mixing matrix is consistent with the current data on various types of neutrino oscillation experiments. Our prediction of νμ ↔ ντ probability is smaller than 1.85 ×10−2 with ∆mμτ ≃ 0.7× 10−2 eV, which still lies beyond the scope of the planned CHORUS and other experiments searching for νμ ↔ ντ oscillation. Furthermore, three neutrinos being almost degenerate with ∑ |mνi | ∼ 6 eV, they can be hot dark matter candidates, and the lepton family number breaking effects such as μ → eγ and μ → 3e will be very small. ∗On leave of absence from Dept. of Physics, Seoul National University
122362560
Gaugino condensation and the cosmological implications of the hidden sector
Abstract We investigate the cosmological implications of models in which the breakdown of supersymmetry proceeds via gaugino condensation in a hidden sector, only gravitationally coupled to the observable sector. Semistable particles in the hidden sector are forbidden in the range between 100 eV and a few times 10 10 GeV. These constraints derived from the restrictions on energy density and nucleosynthesis are shown to have consequences for model building. As a byproduct of these investigations we point out a particularly attractive solution of the μ-problem and the strong CP -problem with a composite hidden sector axion.
121333200
Charm and fancy changing neutral currents with five quarks
Abstract We propose a five-quark weak interaction model based on the SU(2) × U(1) × U(1)′ gauge group. The fifth quark f with fancy flavor has electric charge 2 3 . The model induces the charm and fancy changing neutral currents in a natural fashion which are responsible for substantial D0 − D 0 mixing to explain the observed wrong-sign dimuon events. However, these flavor changing neutral currents do not couple to leptons, thus forbidding trimuons to appear as the experiments indicate thus far. We discuss in addition how our model can be extended to a vector-like theory.
64166550
EUDG IMPLEMENTATION IN KOREA FOR HIGH-ENERGY PHYSICS STUDY
Researchers in high energy physics (HEP) have had difficulties securing enough computing powers to store and process tons of data produced from accelerators. In addition, the fact that the researchers are distributed over the world compromises the efficiency of the high energy physics researches which are cooperative in nature. Grid, the so-called next generation Internet, is expected to overcome these difficulties. By integrating computing resources distributed over the world, Grid will allow increased accessibility to data, necessary computing powers, and storage space. In this paper, we describe the initial implementation experiences of HEP Data Grid in Korea using European Data Grid (EUDG) software developed by CERN.