119291744
Neutrino masses and mixings in the baryon triality constrained minimal supersymmetric standard model
We discuss how the experimental neutrino oscillation data can be realized in the framework of the baryon triality ($B_3$) constrained supersymmetric Standard Model (cSSM). We show how to obtain phenomenologically viable solutions, which are compatible with the recent WMAP observations. We present results for the hierarchical, inverted and degenerate cases which illustrate the possible size and structure of the lepton number violating couplings. We work with a new, as yet unpublished version of SOFTSUSY, where we implemented full one--loop neutrino masses. Finally, we shortly discuss some phenomenological implications at the LHC.
14834509
Electroweak Contributions to Squark Pair Production
We compute electroweak contributions to the production of squark pairs at hadron colliders. These include the exchange of electroweak gauge bosons in the $s-$channel as well as electroweak gaugino exchange in the $t-$ and/or $u-$channel. In many cases these can interfere with the dominant QCD contributions. As a result, we find sizable contributions to the production of two SU(2) doublet squarks. At the LHC, they amount to 10 to 20% for typical mSUGRA (or CMSSM) scenarios, but in more general scenarios they can vary between -40 and $+55%$, depending on size and sign of the SU(2) gaugino mass. The electroweak contribution to the total squark pair production rate at the LHC is about 3.5 times smaller.
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.
119172488
Light Stop Searches at the LHC in Events with two b-Jets and Missing Energy
We propose a new method to discover light top squarks (stops) in the co-annihilation region at the Large Hadron Collider (LHC). The bino-like neutralino is the lightest supersymmetric particle (LSP) and the lighter stop is the next-to-LSP. Such scenarios can be consistent with electroweak baryogenesis and also with dark matter constraints. We consider the production of two stops in association with two b-quarks, including pure QCD as well as mixed electroweak-QCD contributions. The stops decay into a charm quark and the LSP. For a higgsino-like light chargino, the electroweak contributions can exceed the pure QCD prediction. We show the size of the electroweak contributions as a function of the stop mass and present the LHC discovery reach in the stop-neutralino mass plane.
118753210
CP asymmetries in the supersymmetric trilepton signal at the LHC
In the CP-violating Minimal Supersymmetric Standard Model, we study the production of a neutralino–chargino pair at the LHC. For their decays into three leptons, we analyze CP asymmetries which are sensitive to the CP phases of the neutralino and chargino sector. We present analytical formulas for the entire production and decay process, and identify the CP-violating contributions in the spin correlation terms. This allows us to define the optimal CP asymmetries. We present a detailed numerical analysis of the cross sections, branching ratios, and the CP observables. For light neutralinos, charginos, and squarks, the asymmetries can reach several 10%. We estimate the discovery potential for the LHC to observe CP violation in the trilepton channel.
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 .
121440952
Axion and axino contribution to dark matter
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.
119287694
Two dark matter components in dark matter extension of the minimal supersymmetric standard model and the high energy positron spectrum in PAMELA/HEAT data
We present a dark matter extension of the minimal supersymmetric standard model to give the recent trend of the high energy positron spectrum of the PAMELA/HEAT experiments. If the trend is caused indeed by dark matter, the minimal supersymmetric standard model needs to be extended. Here, we minimally extend the minimal supersymmetric standard model with one more dark matter component N together with a heavy lepton E and introduce the coupling e{sub R}E{sub R}{sup c}N{sub R}. This coupling naturally appears in the flipped SU(5) grand unification models. We also present the needed parameter ranges of these additional particles.
117909109
The photino, the axino and the gravitino in cosmology
11881623
Neutrino mass and lepton number violation with charged scalars
If there exist only three light neutrinos below the weak scale, the neutrino masses can arise by breaking the lepton number L. One example is the Zee mechanism for the neutrino masses. We study phenomenological implications of neutrino masses arising from the L violation through introduction of SU(2) X U(1) singlet scalars with Q_{em}=1 and 2.