13595363
CheckMATE: Confronting your favourite new physics model with LHC data
Abstract In the first three years of running, the LHC has delivered a wealth of new data that is now being analysed. With over 20 fb−1 of integrated luminosity, 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 task. Check mate (Check Models At Terascale Energies) is a program package which accepts simulated event files in many formats for any model. The program then determines whether the model is excluded or not at 95% C.L. by comparing to many recent experimental analyses. Furthermore the program can calculate confidence limits and provide detailed information about signal regions of interest. It is simple to use and the program structure allows for easy extensions to upcoming LHC results in the future. Program summary Program title: CheckMATE Catalogue identifier: AEUT_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEUT_v1_0.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.: 179960 No. of bytes in distributed program, including test data, etc.: 6089336 Distribution format: tar.gz Programming language: C++, Python. Computer: PC, Mac. Operating system: Linux, Mac OS. RAM: Bytes Classification: 11.9. External routines: ROOT, Python, Delphes (included with the distribution) 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. Solution method: CheckMATE is a program package which accepts simulated event files in many formats for any model. The program then determines whether the model is excluded or not at 95% C.L. by comparing to many recent experimental analyses. Furthermore the program can calculate confidence limits and provide detailed information about signal regions of interest. It is simple to use and the program structure allows for easy extensions to upcoming LHC results in the future. 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-kt jet algorithm [4]. • C L s prescription [5]. • In analyses that use the MT2 kinematical discriminant we use the Oxbridge Kinetics Library [6, 7] and the algorithm developed by Cheng and Han [8]. • 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 50 s/1 s 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 arXiv:1307.6346 . [2] M. Cacciari, G.P. Salam, G. Soyez, FastJet User Manual, Eur. Phys. J. C72 (2012) 1896. arXiv:1111.6097 , http://dx.doi.org/10.1140/epjc/s10052-012-1896-2 . [3] M. Cacciari, G.P. Salam, Dispelling the N3 myth for the k t jet-finder, Phys. Lett. B641 (2006) 57–61. arXiv:hep-ph/0512210 , http://dx.doi.org/10.1016/j.physletb.2006.08.037 . [4] M. Cacciari, G.P. Salam, G. Soyez, The Anti-k(t) jet clustering algorithm, JHEP 0804 (2008) 063. arXiv:0802.1189 , http://dx.doi.org/10.1088/1126-6708/2008/04/063 . [5] A.L. Read, Presentation of search results: the cl’s technique, Journal of Physics G: Nuclear and Particle Physics 28 (10) (2002) 2693. URL http://stacks.iop.org/0954-3899/28/i=10/a=313 [6] C. Lester, D. Summers, Measuring masses of semiinvisibly decaying particles pair produced at hadron colliders, Phys. Lett. B463 (1999) 99–103. arXiv:hep-ph/9906349 , http://dx.doi.org/10.1016/S0370-2693(99)00945-4 . [7] A. Barr, C. Lester, P. Stephens, m(T2): The Truth behind the glamour, J. Phys. G29 (2003) 2343–2363. arXiv:hep-ph/0304226 , http://dx.doi.org/10.1088/0954-3899/29/10/304 . [8] H.-C. Cheng, Z. Han, Minimal Kinematic Constraints and m(T2), JHEP 0812 (2008) 063. arXiv:0810.5178 , http://dx.doi.org/10.1088/1126-6708/2008/12/063 .
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.
118182564
A Simple Baryon Triality Model for Neutrino Masses
We make a simple ansatz for the supersymmetric lepton-number violating Yukawa couplings, by relating them to the corresponding Higgs Yukawa couplings. This reduces the free B$_3$ parameters from 36 to 6. We fit these parameters to solve the solar and atmospheric neutrino anomalies in terms of neutrino oscillations. The resulting couplings are consistent with the stringent low-energy bounds. We investigate the resulting LHC collider signals for a stau LSP scenario.
53580211
The higgsino–singlino world at the large hadron collider
We consider light higgsinos and singlinos in the next-to-minimal supersymmetric standard model at the large hadron collider. We assume that the singlino is the lightest supersymmetric particle and that the higgsino is the next-to-lightest supersymmetric particle with the remaining supersymmetric particles in the multi-TeV range. This scenario, which is motivated by the flavor and CP issues, provides a phenomenologically viable dark matter candidate and improved electroweak fit consistent with the measured Higgs mass. Here, the higgsinos decay into on (off)-shell gauge boson and the singlino. We consider the leptonic decay modes and the resulting signature is three isolated leptons and missing transverse energy which is known as the trilepton signal. We simulate the signal and the Standard Model backgrounds and present the exclusion region in the higgsino–singlino mass plane at the large hadron collider at $$\sqrt{s}=14$$s=14 TeV for an integrated luminosity of 300 fb$$^{-1}$$-1.
16726847
Testing neutrino masses in the R-parity violating minimal supersymmetric standard model with LHC results
Within the R–parity violating minimal supersymmetric standard model (MSSM), we use a hierarchical ansatz for the lepton–number violating trilinear Yukawa couplings by relating them to the corresponding Higgs–Yukawa couplings. This ansatz reduces the number of free parameters in the lepton–number violating sector from 36 to 6. Baryon–number violating terms are forbidden by imposing the discrete gauge symmetry Baryon Triality. We fit the lepton–number violating parameters to the most recent neutrino oscillation data, including the mixing angle θ13 found by Daya Bay. We find that we obtain phenomenologically viable neutrino masses and mixings only in the case of normal ordered neutrino masses and that the lepton–number violating sector is unambiguously determined by neutrino oscillation data. We discuss the resulting collider signals for the case of a neutralino as well as a scalar tau lightest supersymmetric particle. We use the ATLAS searches for multi–jet events and large transverse missing momentum in the 0, 1 and 2 lepton channel with 7 TeV center–of–mass energy in order to derive exclusion limits on the parameter space of this R–parity violating supersymmetric model.
119300805
Light stop phenomenology
We consider the discovery potential of light stops in the MSSM at the LHC. Here, we assume that the lightest neutralino is the LSP and that the lighter stop i s the NLSP. Direct stop pair production is difficult to probe in scenarios with a small mass splitting between the stop and a neutralino. We discuss two different search channels: the monojet and the two b‐flavoured jets and large missing transverse energy signature. We present the discovery reach in the stop‐neutralino mass plane for both channels. The latter process is sensitive to the stop‐h iggsino‐b quark coupling. This allows us to test a supersymmetry relation involving superpotential couplings. We briefly comment on the possible precision with which the coupling can be measured.
13291931
Hidden sector gaugino condensation and the model independent axion
Abstract In the effective field theory framework, we consider the effect of supersymmetry breaking via gaugino condensation and supergravity in the hidden sector gauge group on the hidden sector vacuum angle θ h . The θ h parameter dependence of the potential yields phenomenologically acceptable invisible axion solutions if the U (1) R symmetry is broken down to a discrete subgroup Z N with N ≥3 ( N =4 is marginal). Anomalous U(1) superstring models are good candidates for this invisible axion resolution of the strong CP puzzle.
56138229
Gauge CP symmetry, wormhole effects, and strong CP problem
The recent observation of four dimensional CP as a discrete gauge symmetry in 8k + 1, 8k + 2 and 8k + 3 Minkowski dimensions calls for a serious reconsid­ eration of various solutions of the strong CP problem. In these possible higher dimensions, the relevant one is a ten dimensional string theory in which a possi­ bility of light fermions exists. We point out that the model independent axion in the heterotic string theory solves the strong CP problem. We also point out that the wormhole effects to low energy global and discrete symmetries are negligible. .. " JIf',!\f':-,',f,' ,. aJ , I <\ " ; \ ,k fL .::LJ.i2" ('If"T 11 . J' ., __ ".1: 1992 11!llllnrB1i1111111 -SAlUT? -·9/ --..5~ o 11bO 0011852 5 .................. • The recent observation of four dimensional CP as a discrete gauge symmetry in 8k +1, 8k +2 and 8k +3 Minkowski dimensions [1] calls for a new understand­ ing on the weak CP violation and the strong CP invariance. Among the possible higher dimensions, the relevant one is 10 because there exists a phenomenologi­ cally viable heterotic string theory [2]. The other extra dimensions not utilized by nature are only of academic interest. In the heterotic string theory, it has been known that the four dimensional CP must be a gauge symmetry since the theory does not have any discrete symmetry except Es +-+ E~ [3]. The discrete symmetry Es +-+ E~ cannot contain the four dimensional CP of light fermions and anti-fermions since they are singlets of E~. In string theories, therefore, the required weak CP violation must arise through spontaneous breaking [4]. The Kobayashi-Maskawa weak CP phase which looks like a hard CP violation at low energy may in fact have descended down from string scale physics through spon­ taneous breaking mechanism [5]. Inflation after the spontaneous CP violation might have removed the dangerous domain walls from our observable universe. The 'calculability' solutions of the Nelson-Barr type [6] to the strong CP problem have a rationale (8QCD = 0) in higher dimensions due to CP as a discrete gauge symmetry of Lagrangian. However, there are two questions to be cleared regarding the strong CP prob­ lem. Firstly, should we consider extra dimensions? Second, what is the effect of gravity on the four dimensional low energy symmetries? In this Letter, we consider both of these questions from Planck scale physics. Regarding the first question, an extension of spatial dimensions should not be in contradiction with low energy physics. Phenomenologically, there is no reason to extend the spatial dimensions. However, one may try to include more spatial dimensions to solve theoretical problems of the standard model. So in consideration of dis'crete and global symmetries in higher dimensions, at present the ten dimensional heterotic string is the only one to be considered. Thus, let us consider the (} parameter in the heterotic string theory in ten dimension. The heterotic string has a model-independent axion aMI [7] whose decay constant is
115614046
ORBIFOLD COMPACTIFICATION TOWARD STANDARD MODEL
Superstrings are supposed to be a candidate theory for unifying all known interactions. It will fail to be a physical theory if it turns out to be successful only for gravity. Therefore, the ultimate hope is to find a standard model from the string approach. One route to this objective is to go through D=10 N=l supergravity compactified on a Calabi -Yau space.1 Another more promising approach is to obtain 4 dimensional string models through orbifold compactifications.2,3
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.
29571166
Localized gravity and mass hierarchy in D = 6 with Gauss-Bonnet term
We obtain the localized gravity on the intersection of two orthogonal non-solitonic or solitonic 4-branes in D=6 in the presence of the Gauss-Bonnet term. The tension of the intersection is allowed to exist unlike the case without the Gauss-Bonnet term. We show that gravity could be confined to the solitonic 4-branes for a particular choice of the Gauss-Bonnet coupling. If the extra dimensions are compactified with the $T^2/(Z_2\times Z_2)$ orbifold symmetry, the mass hierarchy between the Planck scale and the weak scale can be explained by putting our universe at the TeV intersection of positive tension located at the orbifold fixed point.