A Review of the Mass Measurement Techniques proposed for the Large Hadron Collider

We review the methods which have been proposed for measuring masses of new particles at the Large Hadron Collider paying particular attention to the kinematical techniques suitable for extracting mass information when invisible particles are expected.Comment: 72 pages - in form to be published in JPhys

Re-weighing the evidence for a Higgs boson in dileptonic W-boson decays

We reconsider observables for discovering and measuring the mass of a Higgs boson via its di-leptonic decays: H --> WW* --> l nu l nu. We define an observable generalizing the transverse mass that takes into account the fact that one of the intermediate W-bosons is likely to be on-shell. We compare this new variable with existing ones and argue that it gives a significant improvement for discovery in the region m_h < 2 m_W.Comment: 3 pages, 2 figures. Changes in v2: (i) implemented a model of detector smearing, (ii) switched LHC simulation from 14 TeV to 7 TeV running, (iii) presenting results for 10 rather than 3 inverse femtobarns, (iv) corrected a typo in Fig 2 legend. Changes in v3: included published erratu

Building Morality: A New Strategy for Creating Human-Like Moral Psychology in Artificial General Intelligence

Humanity seems well on its way to creating artificial general intelligence, or AGI, within the next century. Such a creation poses great existential risk to humanity, as an AGI of suitable power could conceivably wipe us all out, either by accident or through actual malevolence, and this threat has lead many to search for a solution to the “Control Problem”. Current theories propose various kinds of rule-based solutions, like Asimov’s Three Laws of Robotics, supposing that a rule-based system would be sufficient for creating a cooperative AGI. I argue that this is not the case; rather, what is necessary is an AGI with a human-like moral system. Building on the work of Rawls and Mikhail, I have created a property-based, explanatorily accurate theory of moral grammar, which I believe will allow us to create human-like moral grammar in AGI. This, I argue, is the only way to ensure that our creations will be cooperative and work for the betterment of humanity rather than ending it

Finding Higgs bosons heavier than 2 m_W in dileptonic W-boson decays

We reconsider observables for discovering a heavy Higgs boson (with m_h > 2m_W) via its di-leptonic decays h -> WW -> l nu l nu. We show that observables generalizing the transverse mass that take into account the fact that both of the intermediate W bosons are likely to be on-shell give a significant improvement over the variables used in existing searches. We also comment on the application of these observables to other decays which proceed via narrow-width intermediates.Comment: v1:4 pages, 1 figure; v2: 6 pages, 2 figures, substantially revise

Use of an Activity Monitor and GPS Device to Assess Community Activity and Participation in Transtibial Amputees

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).This study characterized measures of community activity and participation of transtibial amputees based on combined data from separate accelerometer and GPS devices. The relationship between community activity and participation and standard clinical measures was assessed. Forty-seven participants were recruited (78% male, mean age 60.5 years). Participants wore the accelerometer and GPS devices for seven consecutive days. Data were linked to assess community activity (community based step counts) and community participation (number of community visits). Community activity and participation were compared across amputee K-level groups. Forty-six participants completed the study. On average each participant completed 16,645 (standard deviation (SD) 13,274) community steps and 16 (SD 10.9) community visits over seven days. There were differences between K-level groups for measures of community activity (F(2,45) = 9.4, p < 0.001) and participation (F(2,45) = 6.9, p = 0.002) with lower functioning K1/2 amputees demonstrating lower levels of community activity and participation than K3 and K4 amputees. There was no significant difference between K3 and K4 for community activity (p = 0.28) or participation (p = 0.43). This study demonstrated methodology to link accelerometer and GPS data to assess community activity and participation in a group of transtibial amputees. Differences in K-levels do not appear to accurately reflect actual community activity or participation in higher functioning transtibial amputees

Community activity and participation are reduced in transtibial amputee fallers: a wearable technology study

This author accepted manuscript (post print) is made available in accordance with the publisher copyright policy.Wearable technology is an important development in the field of rehabilitation as it has the potential to progress understanding of activity and function in various patient groups. For lower limb amputees, falls occur frequently, and are likely to affect function in the community. Therefore, the purpose of this study was to use wearable technology to assess activity and participation characteristics in the home and various community settings for transtibial amputee fallers and non-fallers. Participants were provided with an accelerometer-based activity monitor and global positioning system (GPS) device to record activity and participation data over a period of seven consecutive days. Data from the accelerometer and GPS were linked to assess community activity and participation. Forty-six transtibial amputees completed the study (79% male, 35% identified as fallers). Participants with a history of falls demonstrated significantly lower levels of community activity (p=0.01) and participation (p=0.02). Specifically, activity levels were reduced for recreational (p=0.01) and commercial roles (p=0.02), while participation was lower for recreational roles (p=0.04). These findings highlight the potential of wearable technology to assist in the understanding of activity and function in rehabilitation and to further emphasise the importance of clinical falls assessments to improve the overall quality of life in this population

The stransverse mass, MT2, in special cases

This document describes some special cases in which the stransverse mass, MT2, may be calculated by non-iterative algorithms. The most notable special case is that in which the visible particles and the hypothesised invisible particles are massless -- a situation relevant to its current usage in the Large Hadron Collider as a discovery variable, and a situation for which no analytic answer was previously known. We also derive an expression for MT2 in another set of new (though arguably less interesting) special cases in which the missing transverse momentum must point parallel or anti parallel to the visible momentum sum. In addition, we find new derivations for already known MT2 solutions in a manner that maintains manifest contralinear boost invariance throughout, providing new insights into old results. Along the way, we stumble across some unexpected results and make conjectures relating to geometric forms of M_eff and H_T and their relationship to MT2.Comment: 11 pages, no figures. v2 corrects minor typos. v3 corrects an incorrect statement in footnote 8 and inserts a missing term in eq (3.9). v4 and v5 correct minor typos spotted by reader

m_T2 : the truth behind the glamour

We present the kinematic variable, m_T2, which is in some ways similar to the more familiar `transverse-mass', but which can be used in events where two or more particles have escaped detection. We define this variable and describe the event topologies to which it applies, then present some of its mathematical properties. We then briefly discuss two case studies which show how m_T2 is vital when reconstructing the masses of supersymmetric particles in mSUGRA-like and AMSB-like scenarios at the Large Hadron Collider