HONR268N

9/19/2020

HW1:

Similarities and differences between electron, muon, and tau leptons:

Commands:

• • 'mkdir' - makes a directory

  • 'cd ../..' - changes a directory

9/21/2020

LECTURE

• learned about fundamental particles

• apparently the universe can fully collapse at any time due to the probability of fundamental particles, if they aren't where they are "supposed" to be I could be "transported to mars"

• starting HW2

HW2: 

Fundamental particles: 

• quarks (up, down, top, bottom, strange, charm) 

  • leptons (electron, electron neutrino, muon, muon neutrino, tau, tau neutrino)

Fundamental forces: 

• strong

• weak

• electromagnetic 

• gravitational

Particles in standard model of physics:

1. up quark

2. down quark

3. charm quark

4. strange quark

5. top quark

6. bottom quark

7. electron

8. electron neutrino

9. muon

10. muon neutrino

11. tau

12. tau neutrino

13. gluon

14. photon

15. W boson

16. Z boson

17. higgs boson

Spin of fundamental particles: spin is the angular momentum, the way it turns about an axis

• 1/2

  • except gluon, photon, W boson, and Z boson have spin 1

  • higgs boson has spin 0

Difference between bosons and fermions

• fermions: build matter

• bosons: cause interactions

What is Linux?

Linux is an operating system just like Mac and Windows, except Linux allows users to understand and see exactly what is it doing. 

What is a Linux Shell?

A place in which the user runs their commands to the computer.

How do you find which shell your are working in?

Type "echo $0"

What is basic linux command structure?

command -option1 -option2 -option3... tagret1 target2

What do the following commands do?

• pwd - shows current directory

• ls - shows where I've logged onto

• ls -l - shows how many times I have logged on

• ls -lr - shows how many times I've logged on, where I have, and the amount of other users that have also logged on

• ls .. - shows everyone that has logged on

• ls -CFx cdls - cannot access cdls, the file doesn't exist

  • cd .. - changes a directory

  • mkdir - makes a directory

• find - shows me a bunch of different places

• rmdir - removes the directory if empty

• which - gives information about other commands typed in after it

• whoami - tells me who I am, my username

• echo - anything typed in after echo is told back to me in the next line

• cat - allows to create a new file

• more - view context of a text file

What is the difference between ls, ls ., and ls .., ls /, ls ./

ls and ls . and ls ./ are the same thing, ls .. refers to a directory one level up, ls / is a directory above that

How can get help to learn more about linux commands on the command line?

use --help  after any command

What is symbol ~ used for in the directory structure?

Allows you to reference your home directory

What do uparrow and enter keys do?

up arrow allows you to do the same command as you did on the line before, the enter key allows you to run the command typed into the current line

What kind of programs/apps you can use to open the following file types: 

• .txt - wordpad

• .C - notepad

• .cpp - notepad, repl.it

• .root - root 

• .sh - vim

• .csh - photoshop

What do operators, > and >> do?

> overwrites the file or creates one if it doesn't exist, >> appends to a file or creates one if it doesn't exist

What is emacs?

emacs is a text editor

What is the difference between the commands?

• emacs -nw mycode.C - terminal mode 

• emacs mycode.C - edit the C code

• emacs mycode.C & - run background process

What do you expect to happen if you run the command ‘emacs myfile.txt &’ where the file myfile.txt does not exist already.

a new file is created

How do you save a file in emacs?

type C-x

How do you search some string in emacs?

C-s

What did it seem like the 'touch' command does?

update time stamp of the file

Why do you think we include that '.' after the 'find' commands?

to separate the command from the thing we are finding 

Based on the outputs from the four 'find' commands, what purpose do you think the '*' character serves? (Hint: it's called the "wildcard" character in linux jargon)

I think it means any file with that word or number in it comes up

What did the 'rm' command do, and how do you think 'rm' differs from the 'rmdir' command we saw earlier? Warning: There is no way to undo the 'rm' command!

removes the directory no matter what, not just if empty

Finally, to test your understanding, why do you think that you should never run the command 'rm *'? True story: a thoughtless 'rm *' almost deleted all of Toy Story 2! (https://www.youtube.com/watch?v=8dhp_20j0Ys)

deletes anything with a name

Try the following commands and answer the questions below. echo "test", echo "test1" > log.txt, ls, cat log.txt, echo "test2" > log.txt, cat log.txt, echo "test3" >> log.txt, cat log.txt

What do the '>' and '>>' operators do? How are they similar? How are they different?

> and >> creates new directory, >> adds to the directory, > makes the only thing on the directory what you put after

What is one potential danger of using the '>' operator?

could delete what is currently in the directory

What do you expect to see if you run:

• ls -l > log.txt - nothing until I run the cat code

• cat log.txt - showing me who was in this directory and when, just me

Use google and collect 10 Linux commands that you think could be useful for you. For example, one such command would be to find and replace a word or phrase in a large text file. Show that your commands actually work.

1. df shows used space on my computer 

1. exit closes window, not sure how to show this one worked, but my window closed and I have to log in again

2. finger gives me user information (directory, last login, etc...) 

1. free gives memory usage of my computer 

1. history gives history of commands used (including when I spelled history wrong...) 

1. pwd prints current directory 

1. printf '....' changes color of text or background 

1. clear clears all previous commands and gives a clean command space (clear was typed before this) 

• 1. cal displays a calendar 

• 1. passwd changes password (took my a few tries to get a "good" password) 

9/23/2020

LECTURE

• spin works about the same in very small particles and in very big objects

• there are many symmetries in particle physics

• photon is the only massless particle

• other "charges" called colors in quarks and gluons, neither can exist alone, outside of the nucleus their color needs to be neutralized

• quantum mechanics is confusing

• continued on HW2 and starting HW3

HW3:

What is a shell script?

a list of commands run by an interpreter

What do line #!/bin/tcsh on top of a shell script means?

defines what shell you are using for interpreting and running the script

What is command 'chmod +x' used for?

makes a file executable

What do ’touch’ command do?

touch can change timestamps on files or create a file

How do you execute a shell scripts?

you can run the script using ./<filename>

What is the argument to a shell script?

arguments to shell scripts are basically the variable being put into the script

What is the difference between ’sometext’ and ‘$sometext’ in a shell script?

sometext is just text, $sometext is the variable assigned under that text

What is piping (|) in linux and how to use it?

piping transfers information from one command to other commands, to use it you do "where the output is | where it will be inputted" 

How can you search and replace something in a file from command line or from within a shell script.

to find a file you use the cat command, to replace certain words you use this: sed -i 's/old-text/new-text/g' input.txt

testscript.tcsh

tcsh ./testscript.tcsh <argument>

(where instead of the word argument you would use a different word such as "cms" or "make".) Can you figure out what this script does? 

it seems like this script displays the usernames of all accounts in the directory above me who have used this script

many more names later... 

./testscript.tcsh <argument>

ls –l testscript.tcsh

chmod +x testscript.tcsh

ls –l testscript.tcsh

./testscript.tcsh  <argument>

What do you think chmod command does?

makes the file excecutable

Now, as an exercise, try using emacs to write a simple script based on testscript.tcsh called homesearch.tcsh which takes one input, <input>.

homesearch.tcsh should search your home directory and its subdirectories for any files which contain <input> somewhere in their name. Finally, homesearch.tcsh should log the results of the search to a file called homesearch_<input>.txt. (Don't forget to 'chmod +x' your new script!) Try:

touch testfile

./homesearch.tcsh testfile

cat homesearch_testfile.txt

What is the output of this script?

not sure if I did this right, but I definitely converted the output to the correct file 

In Linux, what is piping (done with the symbol  |  )?  Write a short description.

Piping means converting the output of one command to be the input of another command. To do this you do something like this "command1 | command2 | command3 | ......" The data flows through the connected commands. 

The command

sed -i -e 's/one/two/g' test.txt

searches the word "one" everywhere in the file test.txt and replaces it with the word "two."

Copy paste the following text to create test.txt file in your directory. Write a script that uses this and/or other commands to :

1. replace every "was" with "is"

It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity, it was the season of Light, it was the season of Darkness, it was the spring of hope, it was the winter of despair, we had everything before us, we had nothing before us, we were all going direct to Heaven, we were all going direct the other way—in short, the period was so far like the present period, that some of its noisiest authorities insisted on its being received, for good or for evil, in the superlative degree of comparison only.

There were a king with a large jaw and a queen with a plain face, on the throne of England; there were a king with a large jaw and a queen with a fair face, on the throne of France. In both countries it was clearer than crystal to the lords of the State preserves of loaves and fishes, that things in general were settled for ever.

It was the year of Our Lord one thousand seven hundred and seventy-five. Spiritual revelations were conceded to England at that favoured period, as at this. Mrs Southcott had recently attained her five-and-twentieth blessed birthday, of whom a prophetic private in the Life Guards had heralded the sublime appearance by announcing that arrangements were made for the swallowing up of London and Westminster. Even the Cock-lane ghost had been laid only a round dozen of years, after rapping out its messages, as the spirits of this very year last past (supernaturally deficient in originality) rapped out theirs. Mere messages in the earthly order of events had lately come to the English Crown and People, from a congress of British subjects in America: which, strange to relate, have proved more important to the human race than any communications yet received through any of the chickens of the Cock-lane brood.

France, less favoured on the whole as to matters spiritual than her sister of the shield and trident, rolled with exceeding smoothness down hill, making paper money and spending it. Under the guidance of her Christian pastors, she entertained herself, besides, with such humane achievements as sentencing a youth to have his hands cut off, his tongue torn out with pincers, and his body burned alive, because he had not kneeled down in the rain to do honour to a dirty procession of monks which passed within his view, at a distance of some fifty or sixty yards. It is likely enough that, rooted in the woods of France and Norway, there were growing trees, when that sufferer was put to death, already marked by the Woodman, Fate, to come down and be sawn into boards, to make a certain movable framework with a sack and a knife in it, terrible in history. It is likely enough that in the rough outhouses of some tillers of the heavy lands adjacent to Paris, there were sheltered from the weather that very day, rude carts, bespattered with rustic mire, snuffed about by pigs, and roosted in by poultry, which the Farmer, Death, had already set apart to be his tumbrils of the Revolution. But, that Woodman and that Farmer, though they work unceasingly, work silently, and no one heard them as they went about with muffled tread: the rather, forasmuch as to entertain any suspicion that they were awake, was to be atheistical and traitorous.

In England, there was scarcely an amount of order and protection to justify much national boasting. Daring burglaries by armed men, and highway robberies, took place in the capital itself every night; families were publicly cautioned not to go out of town without removing their furniture to upholsterers' warehouses for security; the highwayman in the dark was a City tradesman in the light, and, being recognised and challenged by his fellow-tradesman whom he stopped in his character of 'the Captain', gallantly shot him through the head and rode away; the mail was waylaid by seven robbers, and the guard shot three dead, and then got shot dead himself by the other four, 'in consequence of the failure of his ammunition': after which the mail was robbed in peace; that magnificent potentate, the Lord Mayor of London, was made to stand and deliver on Turnham Green, by one highwayman, who despoiled the illustrious creature in sight of all his retinue; prisoners in London gaols fought battles with their turnkeys, and the majesty of the law fired blunderbusses in among them, loaded with rounds of shot and ball; thieves snipped off diamond crosses from the necks of noble lords at Court drawingrooms; musketeers went into St Giles's, to search for contraband goods, and the mob fired on the musketeers, and the musketeers fired on the mob; and nobody thought any of these occurrences much out of the common way. In the midst of them, the hangman, ever busy and ever worse than useless, was in constant requisition; now, stringing up long rows of miscellaneous criminals; now, hanging a housebreaker on Saturday who had been taken on Tuesday; now, burning people in the hand at Newgate by the dozen, and now burning pamphlets at the door of Westminster Hall; to-day, taking the life of an atrocious murderer, and tomorrow of a wretched pilferer who had robbed a farmer's boy of sixpence.

All these things, and a thousand like them, came to pass in and close upon the dear old year one thousand seven hundred and seventy-five. Environed by them, while the Woodman and the Farmer worked unheeded, those two of the large jaws, and those other two of the plain and the fair faces, trod with stir enough and carried their divine rights with a high hand. Thus did the year one thousand seven hundred and seventy-five conduct their Greatnesses, and myriads of small creatures—the creatures of this chronicle among the rest—along the roads that lay before them.

initial: 

replacing was with is: 

9/28/2020

LECTURE

• • • video shown about the LHC

• • able to accelerate protons to 99.9% speed of light, when adding more energy (the velocity can't increase, so the mass does (E=mc^2)) their mass increases to about 40x the original mass, protons collide at energy of 14 TeV

  • mass and energy are considered the same, both are in eV

  • circular accelerators - more common because not limited by length

  • linear accelerator (linac) - limited by length 

  • cross section: transversal size of bunch at reaction points

  • luminosity (L): # collisions / cm^2

  • start HW4 and C++

HW4

Show that for small beta relativistic kinetic energy has the same expression as the usual KE (= 1/2 mv2)

KE relative = (γ − 1)mc^2

γ = 1/sqrt(1 - ((v^2)/(c^2)))

γ -1 = (v^2)/(2(c^2))

Show that pseudorapidity and rapidity are same for massless particles.

Pseudorapidity is used to express angles with respect to the beam axis. Rapidity is the hyperbolic angle that differentiates two frames of motion in relativistic velocities. Since relativisic particles don't have a significant mass, their momentum doesn't have to do with mass, so pseudorapidity becomes equal to rapidity. 

Why muons travel farthest in the detector.

Muons travel the farthest because they do not interact with any of the other chambers in the detector. The electromagnetic calorimeter can only stop electrons and photons with matter. Even though muons are charged the same as electrons, they are much heavier, causing much more momentum, so they make it through this chamber with only a curve due to the field. The hadronic calorimeter can only stop hadrons (particles that contain quarks) with atomic nuclei. Therefore, they travel all the way to the muon detector where they usually lose the remainder of their energy. 

How can you create a file with emacs?

emacs -nw filename.filetype

How to print a statement in c++ code.

cout << "statement you want printed" << endl;

what is ‘ #include xyz’ mean in a C++ file?

includes a certain list commands (ex. cout contained in iostream) 

How to add comments in C++?

// comment

How do you compile c++ code to create and executable that you can then run as './executible-name’?

1. create an emacs with the file name executible-name.cpp

2. code something with an output using C++ language

3. C-x , C-c , y

4. g++ executable-name.cpp

5. ./a.out

What does the g++ compiler do?

compiles the code

What punctuation c++ code uses to separate the code lines?

;

What does command 'g++ -dumpspecs’ do?

gives a long list of specs and commands

How you define variables of kind int, double, float, bool,

int/double/float/bool/etc... variable = number;

What do the operators ++ and —, !=, ==, do?

++ adds 1

-- subtracts 1

!= says something is not equal to something else

== sets something equal to something else

How while and for loops work in c++?

while (a variable is less/more than something) {

    something happens;

    the variable -- or ++;

}

for (set initial variable, set parameter, initial varible -- or ++) {

    something happens using set variable in parenthesis;

}

How to add debug statements in the C++code?

You could put many cout statements in your code. You could also set a variable equal to 0 at the start, then change it to equal 1, if the value is 1 with this line, the code is working. 

Line : if(idebug)  cout<<"the current value of my variable is "<<my_variable_name<<endl;

Why muons travel farthest in the detector? You can find the answer using google. Give the reference of your source with the answer. 

Muons travel the farthest because they do not interact with any of the other chambers in the detector. The electromagnetic calorimeter can only stop electrons and photons with matter. Even though muons are charged the same as electrons, they are much heavier, causing much more momentum, so they make it through this chamber with only a curve due to the field. The hadronic calorimeter can only stop hadrons (particles that contain quarks) with atomic nuclei. Therefore, they travel all the way to the muon detector where they usually lose the remainder of their energy. 

References:     http://cms.web.cern.ch/news/muon-detectors     https://atlas.cern/discover/detector/calorimeter 

Photo:    https://physics.stackexchange.com/questions/355652/whats-the-difference-between-muons-and-electrons-in-experiment

What do the ++ and -– operations do? (and does this give you an idea why C++ has its name?)

++ adds 1, and -- subtracts 1, C++ may have it's name because it is new and improved C coding

Try using ++n instead of n++,  and same for the -- operator. What is the difference?

same output, I think it just adds 1 in front instead of after (1+n as opposed to n+1)

MAIN

VARIABLES

SOME OPERATIONS WITH NUMBERS

NON-NUMERIC VARIABLES 1

WHILE LOOP

FOR LOOP

CONVERTING WHILE LOOPS TO FOR LOOPS (TRY IT YOURSELF)

9/30/2020

LECTURE

• particle detection

• a way to "see" things without actually seeing them, we know what they are and what happens when they are put in different situations

• generic detector (innermost layer to outermost): tracking chamber, electromagnetic calorimeter, hadron calorimeter, muon chamber

• particles create tracks within these layers

• depending on where they end up and what kind of tracks they leave, we can see which particles they are

• tracking chamber: detects charged particles

• in electromagnetic and hadron calorimeter chambers the particles interact with the material so eventually run out of energy through creating new particles

• muons travel through all in a straight line, travel the farthest, figure out why in HW4

• https://www.lhc-closer.es/taking_a_closer_look_at_lhc/1.detectors

• continued and finished HW4

10/5/2020

LECTURE

• http://ispy-webgl.web.cern.ch/ispy-webgl/# : interactive simulation of detector

• watched a video tutorial 

• messed with tracker

• jets are the "cones" that tend to be from quarks, they are enclosing the showers of energy coming from a single point

• went over HW4 a little bit

• do HW5 next.....

HW5

Logic statements in C++,  if-else.

shown in "LOGIC STATEMENTS" code

if (condition) - do something if fits condition

else - do this if it doesn't

How you define Pointers in C++? How you can get the address and the value of a pointer?

define: int* p = &i

address: *p

How can you define a pointer with a new memory address?

int* p = new int(value)

Using ‘date' and ‘awk' commands in a script.

used in final script

LOGIC STATEMENTS

POINTERS

PROGRAM1

PROGRAM2

• program 1 creates two variables, j is only dependent on i in the first line, then it wasn't affected by i and i was never affected by j

• program 2 creates one variable then references the pointer to change that variable, changing this variable also changes the data in the pointer and vice versa

DECLARE NEW POINTER

MY CODE USING POINTERS 

Write a small C++ code that shows examples of if and while logic statements.  (START in class). Explain what the code does by using cout statements.

Alter the script given below so that it outputs the list of files that were updated within the current month. Note that the marks which surround date | awk '{print $2}' are not apostrophes, but rather a backticks. The backtick can be found on the same key as '~' (to the left of the '1/!' key). (Hint: the resulting script will be shorter and simpler :-))

10/7/2020

LECTURE:

• looking into a CMS detector

• calorimeters sense energy

• talked for 10 minutes about a coordinate system

• high energy jets don't have the nice separate cones, they are so high energy they don't get impacted by the electric field very much and just form many small cones that may look like few bigger cones

• higgs discovery

10/12/2020

LECTURE

• standard model

  • 3 quark families

  • 3 lepton families

  • force carrier particles

• symmetries in universe are very important

• quantum mechanics + fields + relativity + symmetry

• particle detection

• neutrinos don't react in particle detectors

• conservation of energy and momentum to figure out particles and decays

• E=mc^2

• Galilean : x = x' + vt (v of frame), t = t'

• Lorentz: x = gamma(x' +vt'), t = gamma(t' + (vx')/c^2), gamma = 1/sqrt(1 - v^2/c^2)

• when velocity is small gamma is negligible

• postulates

  • laws of physics do not change

  • speed of light is constant (in vaccum)

• time dilation 

• length contraction

• 4 vectors: (x, y, z, ct) 4D

  • (Px, Py, Pz, E) -> momentum

• r, eta, phi

  • eta depends on theta

• E = gamma(m)

• natural units:

  • c = 1

  • h = 1

  • units: eV

• HW 5 extended to this Friday because cluster is out

Look up:

• phase velocity - can be greater than speed of light, velocity at which electric fields move forward, according to Einstein information can't travel faster than light, this isn't informations

• group velocity - laser light pulses sent through certain materials can exceed the speed of light, group velocity is packets of waves

• medium - place light is moving through, light moves different speeds through different mediums because it interacts with the particles in the medium, in a vacuum there are no other particles to interact to thats where light travels fastest

• c = 299,792,458 m/s

10/14/2020

LECTURE

• more relativity

• time is not absolute

• time dilated

• length contracted

• space time is curved

  • while in this reference frame all is normal

  • outside particles take longer to travel in it

• work on HW5

10/19/2020

LECTURE

• lorentz transformations

• natural units: c and h = 1

• proper time -

• proper length -

• measure particles in frame of reference they are in

• moving clocks runs lower

• moving lengths run shorter

• t = 1/sqrt(1-B^2) * proper time

• L = sqrt(1-B^2) * proper length

10/21/2020

LECTURE

• 4 vectors: x y z t defining a space

  • also used for energy and momentum

• as v approaches c gamma approaches infinity, v cannot exceed c

• action at a distance

  • takes time for one thing to affect something else at a distance

• entanglement

  • two particles are related so you can measure property of one particle and relate it to the property of another instantaneously

• action at a distance and entanglement are paradoxical

• in class assignment: muon life time and relativity, entanglement and action at a distance

10/26/2020

LECTURE

• start HW6

• continue assignment and discussion

HW6

What is ROOT? (answer in the context of LHC data analysis. We are not concerned with any other uses of the word ‘root’)

highest level directory

What does command ‘cmsenv’ do?

sets up environment for root

What happens when you run command ‘root'?

switches to root

What is the difference between commands ‘root' and 'root -l’

root screen vs regular screen

How do you quit a root session?

.quit

Working with arrays in C++.

shown in codes

How can you add single and multiline comments in C++?

single: //

multiline: /* multiline */

How to read data from a file in C++ code?

include fstream

use ifstream to get the file

cout the data from the file

How to create, write into, and close a txt file in C++

include fstream

oftream nameoffile;

myfile.open("file.txt");

myfile<< "text that is written";

myfile.close();

What is the difference between a vector and a scalar in C++?

vector is defined as 2 numbers and scaler is just one

How to use vectors in C++?

int vector[2] = {1, 10};

How to use a random number generator in C++? Which #include file is needed to use this function in your C++ code?

You type in how many times you want to run it and it gives a histogram of the numbers and lists the numbers 

#include <math.h>

What do we mean by the ’seed’ of a random number generator?

number used to initialize the random number generator

What changes in the distribution of random numbers as you increase statistics?

when you enter 10 you only get a distribution with a few specific numbers, when you enter 100000 you get all the numbers evenly

What is ‘class' in C++?

can contain data members as well as data functions

Name two classes you have used in C++ code in this class?

stream, ana

How do you run C++ code with root?

root -l codename.C

How do you book, fill, draw, and save a histogram in C++ code to be used in root?

shown in code if it works (hopefully it will)

update: I figured it out (a miracle)

Note: you can, and in some cases should, use braces to specify rows and columns. Fins a simple example on google

int x[3][4] = {{1,2,3,4}, {5,6,7,8}, {9,10,11,12}};

Try removing this and see how the result changes. What does the & do?

all of the values are zero now

Show how we get to this number?

that number looks similar to how to convert between integer numbers and binary numbers, there are 8 bits in the system, so the maximum number that can be stored is 2^8n -1 

Put a cout statement into the code that makes it print the first 10 “random” numbers it generates. Run the executable a couple of times. What do you notice? (This is why they are called pseudo-random numbers.) Try changing the seed (it should be odd and large).  What happens then?

the numbers outputted are the same every time and don't fill up much of the histogram

the numbers are evenly distributed

Now try changing the number of times you call the random number generator from 1000 to other numbers (say, 10, 100, 100000, etc).  What do you notice about the contents of the histogram?

the histogram becomes more evenly distributed

NOTE: there is an intentional mistake in the code. 

Look at the .C file.  This is root code, so you will run it on the root prompt as

                                                root -l resolutions.C

Set N=1 and run it.  From this "data", what would you guess the mass of the mother particle is?  And, how far would you guess the true mother mass could be from this measured value? 

the mass is about 53, the mother mass should probably be within 10 of this

Now change N to 10.  What do you find? 

the average mass looks to be about 90

Change N to 100?  What do you find? 

the average mass looks to be about 85

Change N to 1000.  What do you find? 

the graph creates a nice point where the mass is about 92

Now open secretparameters.txt and change the first number in it to 1.  Repeat with N=1,10,100,1000.  What have you learned?

the mass is now around 10

ARRAYS AND VECTORS

1

2

(change LL[3][2])

READING DATA FROM FILE

RANDOM NUMBER GENERATOR

N = 1

N = 10

N = 100

N = 1000

10/28/2020

LECTURE

• opened root for the first time, that's about it

11/2/2020

LECTURE

• messed with random number generator

• Energy calibration and resolution of the CMS electromagnetic calorimeter in pp collisions at sqrt(s) = 7 TeV :

• The energy calibration of the electromagnetic calorimeter (ECAL) is accurate and precise. This has been tested using 2010-2011 proton proton collisions with a centre-of-mass energy of sqrt(s) = 7 TeV and integrated luminosities of 5 1/fb. All factors such as stability, alignment, and synchronization were taken care of and calibrated precisely. The data was compared to that of the CMS Monte Carlo simulation, there were initially some inconsistencies, but in the end the results were very similar. For electrons from Z-boson decays, the energy resolution is 2-5% throughout the ECAL barrel; in 125GeV Higgs boson decays, this energy resolution for photons is 1-5%. In conclusion, the CMS ECAL has been successfully calibrated to a very high degree. 

11/4/2020

LECTURE

• U(1) x SU(2) x SU(3)

  • em     weak    strong

  • group theory: quantum mechanics, relativity, fields, and symmetry

  • over arching symmetry group to include everything

  • em+weak+strong

    • electroweak(em+weak)

      • em

      • weak

    • strong

11/9/2020

LECTURE

• going over the report we read

• they are saying higgs is decaying into two photons or z or w or taus 

  • z decay into photon electron or muon

• higgs field interacts with other particles and with itself to give particles mass

• breakout room discussion: mainly went over the conclusion

• the Higgs can decay into a few particle pair options, but after that those particles can decay into other particles and so on and they think they have found something new

• these results are consistent with what they theorized

• with more testing they may find something that goes beyond the standard model

• the decay of the two photons indicates some new particle with a spin "different from one" 

11/11/2020

LECTURE

• • command to copy file: scp file meghanshemer@hepcms.umd.edu:/home/meghanshemer/

  • opened firefox with firefox & (it was very slow) 

  • attempt to open madgraph, it worked

11/16/2020

LECTURE

• discussing the paper (section 5):

• higgs decaying to two gammas is common in the low mass range

• sorting different events to find the most useful and accurate ones

• what happened at the point of collision was hypothesized by things that we know

• the specific event should be when the two photons meet specific criteria, certain mass and certain region and certain probability and certain eta

11/18/2020

HW7

Brief intro to the major detectors parts of the CMS detector.

shown in diagram

What is missing energy?

energy not detected in the detector, but is expected to be there due to laws of conservation

What are jets?

cones made up of hadrons that shoot out in particle collisions

How to distinguish between physics objects in the detector?

depends on their direction, where they are seen, and how far they make it through

11/23/2020

HW 8

How to use TLorentz vector class to get invariant mass of a particle that decays into two partciles?

shown in code

How to get C++ class code automatically from a root file?

HZZ4LeptonsAnalysisReduced->MakeClass("HiggsAnalysis")

numbers that are masses 

discovering Higgs

11/30/2020

LECTURE

• continued to find higgs mass on HW8, update: discovered the Higgs boson 

12/2/2020

HW9

What is the difference between CPU and GPU?

CPU - focuses on individual tasks and getting them done quickly

GPU - use parallel processors to get a lot done

How to define variables and do math operations?

variable=#

Print statements in python?

print(statement)

How to define Function?

def functionname(argument):

How to use inbuilt python functions round, min(), max(), sort(), sum(), len()

just put a variable in the parenthesis

Lists in python.

shown in "cat dog fish" and "legs" and lists

Booleans and Conditonals in python.

shown in boolean codes

% operator in python?

gives remainder when dividing numbers

for and while loop.

show in loop section

What are external liberaries?

other commands and functions that come from another source 

what is ‘import’?

how we import these libraries

How to make a plot and set labels and axes values?

shown in plots

Name two external libraries you used? Exaplin briefly what they are used for?

math - ......math functions

matplotlib - plotting

random function.

numpy has a random function built in

Zoo

Area

Cat dog fish

b=temp, not temp=b, then 2 will be the same as 1

Legs

Rounding to n

All the built in functions

Product of maxes

Boolean

^no output because the strings are the same length

^0 eggs, cannot make cake

% operator

Lists

Loops

Deck

^making and printing deck

^took out spades and added jokers

^cleared

Plots

^mine

CMS Analysis

HONR269L

1/28/2021

Bill Dorland - Developed a new code, called Gkeyll, to study fusion and astrophysical plasmas. This code can solve the Vlasov-Maxwell System, a set of equations. One of the only people in the world with a code that can do this. Studying the physics that is contained in the Vlasov-Maxwell system. This system has to do with the field a plasma creates due to the charged ions in it.

4 Kaustubh Agashe - Studying properties of the top quark with the LHC. Top quark is very heavy, so it decays extremely fast. Studying new models of this using MadGraph.

1 IceCube - Data analysis of IceCube data. The IceCube neutrino Observatory is located in Antarctica and run by CERN. They detect and cosmic and cosmic neutrino beams from as far away as the edge of our galaxy. These neutrinos may be the most energetic particles in existence. The neutrinos may also tell us about events in the universe like exploding stars, gamma-ray bursts, black holes, and neutrino stars. The cosmic rays interact the with atmosphere in strange ways that we don't yet understand.

3 LZ - Studying dark matter, this matter does not interact with electromagnetic waves and it not described in the standard model. The LZ Dark Matter experiment is located in Lead, South Dakota 1 mile underground. Liquified Xenon is used to interact with the dark matter, giving energy to the Xenon, which causes electromagnetic radiation and charged particles. Working on calibration of this energy and analyzing the data using ROOT and PYTHON.

SEGMENTED CRYSTAL CALORIMETERS - Work on making a new type of calorimeter for particle accelerator experiments. Simulate calorimeters and vary the parameters to see what happens. 

2 CMS LHC - Study W and Z bosons and the precision at which we measure them. Look for new physics. 

2/4/2021

ASSIGNMENT : ICE CUBE 

    Ice Cube is a neutrino observatory built in the south pole. The observatory is 1 km^2 in area and built underground. This high energy observatory is meant to detect neutrinos, it can track their paths and trace back where they came from in space. the neutrinos found in the observatory can come from many events in space like star explosions, blazars, and other cosmic events having to do with black holes and neutrino stars. These neutrinos travel straight paths in space because they have no charge and an extremely small mass; therefore they not influenced by any gravitational or electro-magnetic fields. On the other hand cosmic rays have charge and are influenced by electro-magnetic fields, so the neutrinos produced by the same events are much easier to study. The neutrinos coming from these astrophysical events are extremely high energy, way higher than anything we could replicate in an accelerator. One example of this is a neutrino with 300 TeV of energy that was studied in the observatory, compared to the proton collision in the LHC that are only 6.5 TeV. The neutrino observatory acts as a cosmic ray accelerator that we cannot build (yet). When the high energy neutrinos come in contact with the water in the ice, it can create charged leptons which travel through the ice faster than the speed of light in ice and are picked up by the observatory. The research at Ice Cube focuses mainly on neutrino astronomy, cosmic ray physics, neutrino physics, dark matter, and glaciology. 

2/11 - Initial Presentation

• • Happens 2,600 times a day

  • Get 100,000 background neutrinos

  • Doms are very stable due to cold dark, mainly break when the water has to refreeze around them

  • 10-1000x higher than LHC can produce

  • They get a huge load of data, they process many events and have to separate signal effects and background effects

  • Separating signals from background- get so many muons (they are penetrating and come from cosmic rays interacting with the atmosphere), also neutrinos (duh)

    • 1 in a million is a neutrino

    • 1 in a billion is an astrophysical neutrino (!!!! what we want)

  • Many simulations to understand signal and backgrounds

  • Ice is so old and affected by all aspects of nature (much more interesting than regular ice) active research still on this, we study the optics of this ice, want to understand the glacier to better understand the directions, can lessen the error which they report (sharpens focus of the data)

    • The ice was at the surface during a very volcanic point of time, it got a little messy so we have to consider that

    • Ice is one of the major things we don’t understand, well beyond simulation due to pressures, sizes, and temperatures 

    • Although not a major component of systematic errors with such high energy

  • https://youtu.be/rB9Pt05wiG8

  • Small angular difference after neutrino goes to muon or something, kinda sucks but working on it

  • At such high energies, we can clearly see neutrinos from the cosmos (as opposed to atmosphere)

  • Also, neutrinos give off the light when interacting with the ice

  • In atmospheric cosmic rays, neutrinos come with muons so neutrinos with a lot of muons are usually not what we're looking for

  • Track background, we see a lil spike for high energy neutrinos

  • Gives out so much light

  • 2 years - 28 events

  • No super significant source of neutrinos, they can come from all over

  • We can look for sources, pay attention to known sources and track neutrinos from them, look in direction of neutrino direction

2/15 - Looking into files, questions

• • How exactly do the DOMs work? I understand they are optical sensors and they can see the radiation (CHERENKOV) the particles make when passing through the ice, but is that all they track? Can they track the particles the neutrino decays into also?

  • What is the biggest discovery IceCube has made so far?

  • How do we get rid of the angular uncertainty or are we not sure yet? This angular uncertainty happens after the neutrino decays into whatever particle, is it due to energy or the neutrino decaying into multiple particles. If multiple particles could we track both?

  • Have you gotten multiple neutrinos from one source?

  • Building neutrino detectors in water is also common, is ice a better option? Wouldn't water be a better option due to higher density and less uncertainty about glaciers?

  • How does this experiment help understand dark matter?

2/25

• • Into docker? I think

  • Muon - hard to tell energy and if they are astrophysical, but can tell direction less than 1 deg error uncertainty

  • Electron - easier to tell energy and if they are astrophysical, but about 10 deg angular uncertainty

  • Tau - has a double bang, not observed yet

  • 2800 events per sec, filters them

  • Super high energy neutrinos come from the side

    • From up we get a lot of atmospheric neutrinos

    • From down the neutrinos don't make it through 

3/1

• • What do we want to look into

  • Point source analysis

3/4

• • Charge current interactions

    • W boson carries charge to create electron

    • Muons 

  • Focus on muons the most

    • Have the most interactions because of their tracks

    • Best angular resolution

  • 1000:1 event point source

  • Rest are background

  • Looking at events that stack up coming from one point in the sky

  • Neutral current and charge current interaction for electron and tau

  • High energy electrons are rare from cosmic ray

    • High energy electrons usually from exciting events

  • Muons travel farthest

    • Electron interact

    • Tau unstable

3/11 - 4/3

• • Got into lots of coding stuff with binned analysis

4/8 to final

• • Point source analysis using unbinned analysis techniques

  • Unbinned analysis uses likely hood with a variety of factors

  • basically: likely hood this point source is background versus likely hood this point source is signal

  • these likely good functions can be implemented into our code and analysis

ALL CODE IN THIS LINK:

https://github.com/mshemer/Ice-Cube-PS-Analysis

• mla analysis runs are the actual runs I did for the tests of TXS 056+0506

• basic mla analysis goes into unbinned TS (test statistic) using ns (number point sources) as opposed to FN (flux normalization)

• llh ratio explores some unbinned techniques

• the basic skymap countings go into binned analysis, each one building off the last

• data explore was a basic code we looked into early to understand the concepts

FINAL POSTER:

https://docs.google.com/presentation/d/1Zic9sAq-piInBri_CZ8Rf9Sq2M4K3X7nTK8CmywIPqA/edit?usp=sharing