Summer Students 2012

Table of contents:

Proposals

Procedure

• Please go ahead and submit your proposal for CERN summer students urgently tomorrow Feb 15.
• Link for potential supervisors to submit a project proposal(s): http://hrapps.cern.ch/auth/f?p=112:1
• Login: AIS login name and password
• Once you have completed your proposal please don't forget to hit the "create" button in order to submit your proposal as otherwise it will not be registered.

1. laser calib (and possibly more ECAL related)
2. HCAL noise
3. JetMET
4. photons in pile-up
5. razor pheno (optimization of variables etc) more than one can go in here (chris look the bayesian prop by sezen also)
6. Higgs WW, ZZ, gammagamma
7. upgrade/ high pileup related

Javier Duarte

• Razor 1

In the inclusive hadronic razor analysis in CMS, searches for supersymmetry and other new physics are performed using a two-dimensional shape analysis in the razor kinematic variables, R and MR. A maximum-likelihood fit in a control region in R and MR is performed to model the Standard Model (SM) background independently in six different boxes (final state categories). One important feature of the analysis is the universal exponential scaling behavior of the SM backgrounds in the two variables, independent of type (ttbar+jets, W/Z+jets, etc.). The project is to impose this universality at the level of the ML fit by building a simultaneous maximum-likelihood fit workspace for all six boxes in RooFit (thus correlating the exponential shape parameters in all six boxes). This will promote the empirical universal scaling to a fundamental, rather than emergent, part of the razor analysis. The student will also explore how to optimize this procedure in order to use it to interpret the results of the analysis in the framework of the Constrained Minimal Supersymmetric Standard Model as well as simplified models.

• Razor 2

In the inclusive hadronic razor analysis in CMS, searches for supersymmetry and other new physics are performed using a two-dimensional shape analysis in the razor kinematic variables, R and MR. Though the analysis is successful in hadronic channels, it is not known how to modify the analysis to look for new physics involving direct electroweak production in leptonic channels . Specifically, in di-lepton channels, if the leptons emerge from separate cascade decay chains, and thus are well separated, the razor variables are a suitable choice to characterize the event. If the leptons emerge from the same cascade decay, the razor variables do not characterize the event well. One direction the student may explore is how to classify events in the two categories, and thus modify the analysis chain based on the different signatures.

with this expected value for the student:

The student will learn advanced computing methods, data regression, maximum-likelihood fitting, and modern statistical methods. The student will also learn about beyond-the-Standard-Model physics, such as supersymmetry, and the phenomenological implications of LHC results.

Emanuele Di Marco

• H->ZZ: low pt electrons and look-alikes:

Recent CMS data collected at pp collisions at 7 TeV excuded, at 95% confidence level, a Standard Model Higgs boson in the mass domain 127 < mH < 600 GeV, while the direct LEP limit is mH>115 GeV. In the allowed range, CMS finds a 1.9sigma excess at mH=124 GeV. The golden mode in terms of purity and sensitivity to the Higgs mass is H -> ZZ -> 4 leptons final state. The student will work on low level quantities to raise the sensitivity for a mH<130 GeV Higgs boson, such as recostruction of low pT electrons, definition of data control samples to characterize the backgrounds, and will define the custom identification to cope with the new LHC running conditions (8 TeV with increased pileup). He will also study the applications of the full kinematics available in this channel to characterize the properties of a possible signal for a resonance in the still allowed mass range to distinguish a Standard Model Higgs boson from Higgs "look-alikes".

• H->WW: use of singularity variables and razor to enhance mass sensitivity

Recent CMS data collected at pp collisions at 7 TeV excuded, at 95% confidence level, a Standard Model Higgs boson in the mass domain 127 < mH < 600 GeV, while the direct LEP limit is mH>115 GeV. In the allowed range, CMS finds a 1.9sigma excess at mH=124 GeV. For this Higgs mass, due to the large BR and very clean final state, the most sensitive channel at CMS is H->WW->2l2nu. The problem with this decay mode is the absence of a clear mass peak due to two undetected neutrinos. The student should start from the baseline analysis, and revisit the strategy of the usage of available decay kinematics. Recent theory and phenomenological sudies propose the usage of a plethora of singularity variables to search for this mode, and in particular to separate the signal from non-resonant WW production. The student will implement this strategy, and compare the gain in sensitivity using these techniques. He will use the full CMS dataset available.

Adi Bornheim

• New ECAL laser data analysis

The CMS ECAL is optimized for an excellent energy resolution for photons. This is crucial in the search for the Higgs boson decay into two photons. As the mass range in which the Higgs boson is being searched for is narrowing down, the decay mode into two photons is now the most relevant experimental signature for the Higgs search. The CMS ECAL performance depends critically on maintaining the stability of the detector response. This is ensured by a laser monitoring system which measures any instabilities in the hardware with a precision of about 0.1%. This data is used to correct the energy measurement of the ECAL. The light source for the monitoring system will be upgraded in March 2012. The goal of the project is to analyze the monitoring data using the new equipment, quantify its performance and make a comparative study based on physics data to demonstrate the expected improvements in the ECAL resolution.

• Hgg background studies

The search for the Higgs boson is one of the most important objectives of the LHC physics program. As the mass range in which the Higgs boson is being searched for is narrowing down, the decay mode into two photons is now the most relevant experimental signature for the Higgs search. The characteristics of the Higgs boson signal is that of a narrow resonance which has to be disentangled from a large, irreducible background. Optimizing the experimental sensitivity requires an excellent resolution for the photon energy measurement, a very good modeling of the detector response and a detailed understanding of the shape of the signal peak as well as the background spectrum underneath it. The goal of this project is to study various techniques to enhance the sensitivity for the Higgs search by optimizing the description of the signal and background shapes.

Alex Mott

• Trigger

The razor analysis in CMS searches for supersymmetry in a many different channels covering a wide variety of final states and has proven extremely sensitive in 2011. The analysis uses many sophisticated techniques in order to increase the sensitivity to a new physics signal, including careful understanding of the background through maximum-likelihood fits. As with all analysis, this takes quite a bit of time and study to achieve. In 2012, we seek to maximize the likelihood of discovery by implementing a real-time version of the analysis that can look for signs of new physics emerging in the data in real time. The student will implement an analysis to be on a high priority analysis cluster located at CERN, which will be extremely important for maximizing the potential of CMS for discovering supersymmetry in 2012.

Benefits to the student: The student will learn about beyond the Standard Model physics and cutting edge analysis techniques. The student will also learn about online operations and triggering, high-performance computing techniques and event reconstruction.

Artur Apresyan

• Project 1

Many searches for new physics involve signatures of missing transverse energy (MET), which signify presence of weakly interacting particles, such as neutrinos or dark matter candidates. To reliably establish presence of new signal, full control of the MET reconstruction is necessary, free of instrumental noise mimicking the genuine MET. It has been observed in CMS data that sometimes calorimeters record anomalous signals that correspond to particles hitting the transducers which appear as large energy deposits. Such events can then appear as signatures of new physics. The project will study in detail the origins of this noise in HCAL forward detector, by studying MC simulation of such noise hits, and optimizing the identification algorithms based in simulation. As a final stage, the algorithms will be tested in real data, and will be included in default CMS reconstruction to battle the increased rate of HCAL noise in 2012 high luminosity running.

• Project 2

Many searches for new physics involve signatures of missing transverse energy (MET), which signify presence of weakly interacting particles, such as neutrinos or dark matter candidates. To reliably establish presence of new signal, excellent resolution of MET reconstruction is crucial, to separate signals of new physics from known processes, and to measure the parameters of decays of such particles. In 2012 the LHC will attempt to collect as much data as possible by raising number of simultaneous collisions in each bunch crossing, expected average number of collisions being around 30 per crossing. This increased interaction rate will provide more chances to create rare particles. The large occupancy of events will however have a detrimental effect on MET reconstruction, reducing the sensitivity of searches of new physics, since MET resolution will be significantly reduced. The project will work to improving the MET reconstruction performance in CMS, by optimizing the reconstruction parameters used in CMS, and fine-tuning the thresholds of objects used in the MET calculation. The effect will be first studied in high occupancy events using MC and deducing the correlation with generator level quantities, and the results will be compared to CMS data. The improvements in the MET reconstruction will then be tested in the context of searches of new physics in events involving MET, such as SUSY searches.

Students

Alex Atsushi Takeda

• Arrival: June 22, 2012
• Departure: August 31, 2012

Lisa Lee

• Arrival: June 23, 2012
• Departure: after 10 weeks

Valère Lambert

• Arrival: June 22, 2012
• Departure: August 31, 2012

Max Horton

• Arrival: June 25, 2012
• Departure: September 1, 2012

Chun Sung Bong

• Arrival: July 2, 2012
• Departure: September 9, 2012

General Information

Thank you for your email regarding your upcoming summer stay at CERN. This communication is regarding logistics, especially housing and insurance. Making your housing arrangement is up to you. It may be easier and cheaper to arrange rooming but it is entirely up to you. There are a list of resources on the web (see links below) and Ms. Yasemin Yazgan, who is the Relocation Assistant at CERN is also available to assist you.

Important contacts (cc’d in this email):

Ms. Yasemin Yazgan at CERN is the US-CMS contact and Relocation Assistant.

Dr. Iosif Legrand is the Caltech HEP group rep at CERN and needs to sign your registration when you arrive so that you get a valid CERN ID (without which you are not allowed to enter the lab). N.B. Even if your institute has a group at CERN with a different experiment you will get an account with CMS and your host institution will be Caltech for your CERN registration. This will be cross checked with Dr. Legrand when you arrive at CERN.

Dr. Dorian Kcira will help you with computer accounts at the Caltech clusters/T3 and other instructions on getting CMS accounts at CERN and certificates to run jobs on the grid and accessing all the internal CMS pages/twikis/news forums etc. as well as the Caltech/CMS ones.

You will need to arrange your own travel, housing and insurance very soon. I am the Administrative Manager of the HEP group at Caltech and can will help you with any remaining questions. Please keep me informed on all matters regarding health insurance and visas [if needed (French/Swiss)]. This must be done well in advance of your travel date. Also, as soon as you have your travel itinerary finalized, please forward it to me, with a copy to Lupe Llamas at Caltech.

Information on transportation and getting bikes from CERN are included in information below and you can also ask Ms. Yazgan (on the cc) if it is possible to book them now.

Student Housing:

Living in Geneva as an intern: includes health insurance information

http://internationalcenter.umich.edu/swt/work/resources/geneva.html

https://hr-recruit.web.cern.ch/hr-recruit/summies/Housing/Untitled_1.htm

Hostel preferred in Geneva : http://www.cstb.ch/

In France Thoiry: http://www.cstb.ch/

More from Ms Yasemin Uzunefe-Yazgan

Yasemin.uzunefe.yazgan@cern.ch

Relocation Assistant

US-CMS Project Office at CERN

Building 40-R-A02 E19200

CH-1211 Geneva Switzerland

Tel: (+41) 76 487 5868 or 165868

Fax:(+41) 22 766 8361 or 68361

https://twiki.cern.ch/twiki/bin/view/Main/USCMSProjectOfficeCERN

CMS

Advisor; M. Spiropulu

Research Project Mentors/Supervisors at CERN:

Artur Apresyan (Toleman Fellow) , Yi Chen (G3), Chris Rogan (G5) + others from the Caltech Group as needed.

For registrations at CMS: http://cms.cern.ch/iCMS/jsp/secr/reg/regCMS.jsp

Institute: Caltech

Institute Rep: Iosif.Legrand@cern.ch

CMS Workbook: https://twiki.cern.ch/twiki/bin/view/CMS/WorkBook

Caltech T3 accounts and Grid Certificates: Dorian Kcira, dkcira@caltech.edu

CERN

1. Register with CERN and CMS. Carefully follow the instructions on the WorkBookGetAccount Twiki page.

o Complete the CMS pre-registration form.

o Request a CMS Computing Account by email. AFS & NICE passwords are now the same for new users.

o Validate your accounts by passing CERN computer security and rules course.

1. Register your laptop for DHCP to gain access to the CERN domain.
2. Register with HyperNews
3. Some CERN web pages are protected like the ELog. Send email to " helpdesk@cern.ch" and request to be added to the CMS group.
4. If you are going to CERN, please review the CERN Users' Office web page.
5. Register with the Users' Office in the CERN main building (near the main cafeteria). Before you go to the Users' Office, fill out the CERN Registration Form and Proof of Employment Letter.

o Specify "CERN Hostel" for "Local Address in the Geneva Region" if that is where you normally stay while visiting.

o Use "+1-630-555-1212" format for phone numbers in the U.S.

o Use "DD/MM/YYYY" for the date format.

o Talk to Tami Kramer (FNAL/CMS team deputy) in 40/5-A15 (building 40, fifth euro-floor, room A15) -- she can sign your CERN registration form and provide you with a letter confirming your employment at FNAL (or talk to your own team leader if you are not a Fermilab employee).

o You can provide Teri's office on the form, if you do not have your own (phone extension 74799, +41-22-767-4799 from outside CERN).

o If you previously had a CERN ID or "Attestacion" card, you must bring it with you to the Users' Office.

1. Complete CERN Safety Training

o Must be done after receiving a CERN ID card.

o The Users' Office will give you instructions on safety training. Levels 1, 2, and 3 are covered by a video, available at 10:00 and 15:00 in English at room 55/02-005 (near main entrance) -- bring your CERN card to validate/record your training.

o If you will be going down to the CMS cavern (or elsewhere in the LHC tunnel) you must also complete Level 4, which can be done with with an AIS account from http://sir.cern.ch over the web. Generally, all regular CMS members will need to do this (e.g., required for any detector/electronics work and on-site shifts)

1. Obtaining CMS Online Cluster Account

o If you will be doing computing work at P5 (other than checking email from your laptop) then you will need a CMS online cluster account. This can be done only once you have an lxplus/afs account. Send your lxplus/afs user name to the online administrators ( cms-daq-cluster-admins@cern.ch) to request an account. The central user machine on this cluster is called cmsdaquser0.cern.ch

I hope this information is helpful. If you have any questions please contact me and if I can’t answer them for you, I will find the appropriate person to assist you.

CMS Caltech Summer Students Page 2010

Summer Student Index

Caltech Group Information

Group Meetings:
Every Tuesday 12:30 lunch meeting at CERN : Location varies.

Every Thursday 18:30 CERN (09:30 Caltech) in 31-S-023
http://indico.cern.ch/categoryDisplay.py?categId=1587

We said good bye to our beloved slot : Every Wednesday 17:30 CERN (08:30 Caltech) in 4-S-013

Group Information:

• http://hep.caltech.edu/cms/
• https://twiki.cern.ch/twiki/bin/view/CMS/CaltechGroup

Overview of Caltech CMS Group Activities (from DOE Review 2009)
Harvey's ppt slides

CMS Links

CMS main TWiki page:
https://twiki.cern.ch/twiki/bin/view/CMS

iCMS pages:
http://cms.cern.ch/iCMS/

CMS public pages:
http://cms.web.cern.ch/cms/index.html

Tutorials to get started

CMS for summer students: 07 July 2009

http://indico.cern.ch/conferenceDisplay.py?confId=62144

CMS Physics

CMS Physics Technical Design Report
http://cmsdoc.cern.ch/cms/cpt/tdr/

CMS Electromagnetic Calorimeter (ECAL)

Introduction to ECAL pdf

CMS Photons

CMS Photon Trigger Tutorial ppt

CMS Software (CMSSW)

CMS Offline Workbook:
https://twiki.cern.ch/twiki/bin/view/CMSPublic/WorkBook

CMS Software Tutorials:
https://twiki.cern.ch/twiki/bin/view/CMS/Tutorials

Summer School Lectures

CERN Summer Student Lectures
http://indico.cern.ch/categoryDisplay.py?categId=346

The 2009 (CERN-Fermilab) Hadron Collider Physics Summer School
http://indico.cern.ch/conferenceOtherViews.py?confId=44587&view=nicecompact

The 2009 European School of High-Energy Physics
http://physicschool.web.cern.ch/PhysicSchool/2009/Bautzen.html

The 2009 MCNet school on the Physics and Techniques of Event Generators
http://conference.ippp.dur.ac.uk/conferenceOtherViews.py?view=ippp&confId=264

Caltech Ph172 - Experimental High Energy Particle Physics

Notes and Links from Andy and Marat
http://www.hep.caltech.edu/~andyyen/ph172/